JPH04146151A - Ink jet recorder and recording method - Google Patents

Abstract

PURPOSE:To stabilize the quality of recorded image by specifying the angle of carrying direction of a recording medium with respect to a horizontal face in a recording area within a specific range. CONSTITUTION:In an ink jet recorder comprising an ink jet recording head H provided with an ink delivery opposing to a recording medium, a recording area in which the recording medium opposes through a gap to the ink delivery part of the ink jet recording head H and means for carrying the recording medium into the recording area, the angle theta of carrying direction S of the recording medium with respect to a horizontal face in the recording area is set in a range of 25-40 deg. and the ink delivery part Ha in the ink jet recording head H is mounted on a carriage substantially in parallel with the surface of the recording medium thus delivering ink obliquely downward. According to the constitution, the recorder establishes an appropriate recording for different types of recording media.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a recording method and a recording apparatus for recording on a recording medium using an inkjet recording head. The invention particularly applies to printers and facsimile machines.

The present invention relates to an invention applicable to recording devices such as copying machines and word processors.

[Prior Art] Conventionally, two types of inkjet recording heads are known: a continuous type that uses an electromechanical transducer as the mainstream, and an on-demand type that ejects ink at the printing timing of a recording signal or the like.

Among these, ink ejection using thermal energy using an electrothermal converter has the advantage of being able to record ink ejection at high frequencies, and has recently been put into practical use in many cases, and has been adopted in the recording section of various models.

Conventionally, print heads mainly eject ink in a substantially horizontal direction, depending on the conveyance state of a print medium, and in special cases, some print heads eject ink vertically downward.

[Problems to be Solved by the Invention] The present invention is an object of the present invention to solve the following technical problems found by examining the positional relationship between a conventional recording head and a recording medium.

That is, as will be explained in detail later with reference to FIGS. 29 to 31, in a device that discharges ink in the horizontal direction, the recording area of the recording medium is vertical, so the adhered ink may flow and uneven density may occur. It has been discovered that in a device that discharges ink vertically downward, liquid (ink, water, etc.) adheres to the ink discharge portion, disrupting the discharge state.

The present invention recognizes the problem caused by the conveyance state of the recording medium forming the recording area and the configuration of the recording head corresponding thereto as a new technical problem, and the present invention is a recording method and a recording apparatus that solves this technical problem. Particularly, the present invention is characterized in that it maximizes the advantages of a recording head that uses an electrothermal transducer with excellent recording responsiveness as an element for generating energy used for ink ejection. The purpose is to provide a recording method and a recording device that can be used.

Another object of the present invention is to provide recording conditions that can achieve suitable recording for a recording apparatus capable of recording on different types of recording media.

Furthermore, another object of the present invention is to provide more suitable recording conditions for a recording medium having a translucent resin portion with poor ink absorption properties, and to achieve excellent recording even on plain paper. The objective is to provide a recording device that can.

Other objects of the invention will be apparent from the following description.

[Means and effects for solving the problem] The present invention achieves the above-mentioned object, and includes a recording area where a recording medium and an inkjet recording head face each other with a gap therebetween;
An inkjet recording method and apparatus for recording with ink, characterized in that the angle θ formed in the recording area with respect to a horizontal plane in the conveying direction of the recording medium is in a range of 25 degrees or more and 40 degrees or less. According to these aspects of the invention, the problems identified in the invention can be solved while maintaining good recording conditions on various recording media.

More specifically, the present invention provides an inkjet recording head having ink ejection facing a recording medium, a recording area where the recording medium and the ink ejection part of the inkjet recording head face each other with a gap therebetween, and the recording area. and a conveyance means for conveying a recording medium, wherein the conveyance means makes an angle θ in the recording area with respect to a horizontal plane in the conveyance direction of the recording medium in a range of 25 degrees or more and 40 degrees or less, The inkjet recording head is an inkjet recording apparatus characterized in that the ink ejection section is mounted on a carriage in a state substantially parallel to the surface of the recording medium and ejects ink obliquely downward. According to this specific invention, there is an advantage that the above-mentioned effects of the invention can be improved while simplifying the device configuration due to the stable recording state in which the recording head and the recording medium are brought into a substantially parallel state. .

In addition, by determining individual conditions for the configuration of the present invention,
A flexible invention includes an inkjet recording head including an ink ejection section facing a recording medium, a recording area where the recording medium and the ink ejection section of the inkjet recording head face each other with a gap therebetween, and an inkjet recording apparatus comprising: a conveying means for conveying a recording medium, the conveying means being capable of conveying different types of recording media to the recording area; Angle θ with respect to the horizontal plane in the transport direction
is in a range of 25 degrees or more and 40 degrees or less, and the inkjet recording head is configured such that the ink ejection section can be set at different angles with respect to the different recording media, and the ink ejection section is set at different angles with respect to the horizontal plane. The angle θH is 25
This is an inkjet recording apparatus characterized by ejecting ink diagonally downward within a range of 40 degrees or more.

According to this flexible invention, the above-mentioned problem can be solved under the condition that the recording medium and the recording head are within the same angle range, and good recording can be achieved even if there is some variation in the settings of each. There are advantages that can be achieved.

Particularly under this condition, it is more preferable that recording media of different types include a first recording medium with relatively low ink absorption and a second recording medium with higher ink absorption than the first recording medium. 2 recording media, and the angle θ8 of the ink ejection portion with respect to the horizontal plane is smaller with respect to the first recording medium than with respect to the second recording medium. According to this, the effect of the present invention can be relatively improved, and stable high-speed recording can be achieved also on the first recording medium.

Further, under this condition, the different types of recording media have a first recording medium with a relatively low ink absorbency and a second recording medium with a higher ink absorbency than the first recording medium. However, the angle θH of the ink ejection unit with respect to the horizontal plane is set to be a larger angle with respect to the first recording medium than with respect to the second recording medium, so that higher image quality can be achieved. This invention includes a recording means that makes the recording density recorded on the first recording medium within a predetermined time smaller than the recording density recorded on the second recording medium within a predetermined time.

The present invention is particularly effective for the inkjet recording head since it can achieve excellent recording even when the inkjet section has 64 or more inkjet sites. Further, it is more preferable for the present invention that the angle θ and the angle θH are in the range of 25 degrees or more and 35 degrees or less. Of course, the present invention, which includes an electrothermal transducer that generates thermal energy for ejecting ink from the ink ejection portion as the inkjet recording head, is applicable to recording using the electrothermal transducer as described above. Since the advantages of the head can be utilized more stably for recording, the effects of the present invention can be fully demonstrated.

Further features of the invention will be understood from the following description of the examples.

(The following is a margin) [Example 1] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic external perspective view of an inkjet recording apparatus according to an embodiment of the present invention. In Figure 1, 20
01 is a main case that forms part of the device case, and is fixed to a part of the frame of the inkjet recording device, which will be described later in FIG. Cover the area excluding the area corresponding to the width. The home position of the recording head is defined in one of these two end portions, and the recording head is located at this position when not recording, and the ejection recovery unit that performs capping of the ejection port surface of the recording head at this position is the main one. Covered by case 2001. As a result, when a part of the device case is opened to perform maintenance and inspection of the device, it is possible to prevent the recording head or ejection recovery unit from being accidentally touched, causing their position to shift, or damaging them themselves. I can do it.

Reference numeral 2003 denotes a middle case that similarly forms part of the device case, and mainly covers the part where the recording head moves during recording. The middle case 20a3 is provided so that it can be easily attached and detached, and a spur that corresponds to a paper ejection roller described later is attached to a part of the middle case 20a3.By attaching the middle case 2003, this spur can be applied with an appropriate pressing force. Press it against the paper ejection roller. Reference numeral 2005 denotes a paper feed lid that forms part of the device case and is provided so as to be openable and closable. The paper feed lid 2005 is pivoted at both ends of the near side in the drawing in its approximately rectangular shape, and is provided so that it can be opened upward in the drawing and held at a predetermined angle using this as a rotation axis. When the paper feed lid 2005 is held at this angle, it is almost in a straight line with the paper feed tray, which will be described later.
It becomes possible to place recording paper. 200'i is an ink lid provided on the front side of the apparatus and forming a part of the apparatus case. The ink lid 2007 is rotatably supported by a shaft provided at the lower part of the front side of the device, and the lid 2007 can be rotated as needed.
007 can be opened towards the front. This makes it possible to perform attachment/detachment operations such as attachment and detachment of the ink cartridges housed inside.

Reference numeral 2009 is a paper discharge tray that is detachably attached to the apparatus. A paper discharge tray 2009 is mounted at a predetermined angle at the rear of the apparatus, and can sequentially stack recording papers that have been recorded. Reference numeral 2011 denotes an operation section, which is provided on one side of the main case 20 in front of the device. Operation unit 2011
includes a display section 2011B that displays the status of the device, etc., and keys 2011A for inputting various commands to the device.

2 fA) and fB) are a side sectional view and a top view showing an inkjet recording apparatus according to an embodiment of the present invention with the apparatus cover shown in FIG. 1 removed. In addition, the second
Figure (Bl) shows a state in which the recording head, a carriage for mounting and moving the recording head, and a drive system for moving these are omitted.

In Figure 2 (Al and (Bl), 601 is a paper feed tray, which is not shown in the state where the paper feed cover 2005 shown in Figure 1 is opened (Fig. 2 fAl and fB))
Together with this, the paper feed section is configured. The paper feed tray 601 has a rotating shaft 601A provided at the rear end in the paper feed direction.
is rotatably supported by a side plate 2017 forming the device frame, and the front end of the paper feed tray 601 is supported by a spring 60.
2 is biased upward in FIG. 2(A). Due to these configurations, the recording sheets stacked on the paper feed tray 601 (FIG. 2 fA) and (B) are not shown. Also,
In the following, recording paper includes plastic sheets, etc.
(generally refers to a recording medium) has its leading end pressed by a pickup roller 604. In the above-mentioned paper feeding mechanism, 601C shown in FIG. It is a guide plate for
6010 is a groove through which the guide plate 601C moves according to the size of the recording paper.

The pickup roller 604 is a half-moon roller 604Aj:
It consists of a pair of rollers, i and idler roller 604B. As shown in FIG. Half-moon roller 60
It has a circular shape with a diameter slightly smaller than the diameter of the circumferential portion of 4A. Two pairs of pickup rollers 604 consisting of these one pair of rollers are provided near the front end of the paper feed tray 601 at a predetermined interval.
04 is fixed to a pickup roller shaft 604C that extends in a direction perpendicular to the direction in which recording paper is fed. One end of the pickup roller shaft 604C is rotatably supported by a part of the frame 2017, and the other end is connected to the clutch 619. Thereby, the driving force of the motor (not shown) is transmitted to the pickup roller shaft 604C via the clutch 619, and the pickup roller 604 can be rotated.

The recording paper stacked on the paper feed tray 601 is pressed by the pickup roller 604 as described above, so when the pickup roller 604 rotates, the recording paper first
The recording sheet is pushed out by the shoulder portion that connects the cutout portion and the circumferential portion of the half-moon roller 604A, and further, the recording paper conveyance path sent to.

Reference numeral 606 denotes a paper feed roller disposed on the downstream side of the pickup roller 604 on the recording paper conveyance path.

As shown in FIG. 2(B), four paper feed rollers 606 are arranged at predetermined intervals in the width direction of the recording paper being conveyed, and these four paper feed rollers are used to feed the paper. It is fixed to a roller shaft 606A (not shown in FIG. 2 FB+). As a result, the driving force of a paper feed motor (not shown) is transmitted to the paper feed roller shaft 606A, and the paper feed motor 606 can be rotated.

A pinch roller 607 is provided corresponding to each of the paper feed rollers 606, and is arranged so that its circumferential surface is in contact with the circumferential surface of the paper feed roller 606. 611
A pinch roller holder is provided corresponding to each of the pinch rollers 607, and one end of the pinch roller holder rotatably supports the pinch roller 607. Reference numeral 613 denotes a carriage rail, which is provided so as to extend over the movement area of the carriage, which will be described later. Pinch roller holder 6
11 is pivotally supported at its other end by a carriage rail 613, and is urged diagonally downward in FIG. 2 fAi by a spring 614 held between the carriage rail 613 and the pinch roller holder 611. . As a result, the pinch roller 607 presses the recording paper conveyed between the pinch roller 607 and the paper feed roller 606, and the paper feed roller 606 can convey the recording paper by the frictional force generated by this pressing force. can.

Reference numeral 608 denotes a platen for regulating the recording surface of the recording paper, and is disposed on the recording paper conveyance path at a location downstream of the paper feed roller 606 and the like and facing a recording head to be described later. Furthermore, a paper discharge roller 609 is provided on the downstream side of the platen 608. The paper ejection roller 609 is shown in FIG. 2 (B
), nine rollers are arranged at predetermined intervals in the width direction of the conveyed recording paper, and these rollers are connected to the paper ejection roller shaft 609A.
Fixed. The paper ejection roller shaft 609A is rotated by a motor (not shown), and the main case 2001 shown in FIG.
The recording paper is ejected to the paper ejection tray 2009 shown in FIG. 1 by cooperation with the spur held by.

In the recording paper transport path described above, the paper feed tray 601
The recording sheets stacked on top are separated one by one by a pick-up roller 604 and a separating plate 605 and fed to a conveyance path, and the fed recording sheets are guided by a paper guide 608A and passed through a paper feed roller 606. pinch roller 6
07. During this transport, the recording paper
One end of the paper edge detection sensor lever 615 is contacted, and the resulting movement of the other end of the lever 615 causes the paper edge photosensor 6 to
By changing the detection state by 17, the edge of the recording paper can be detected. Further, a reflective paper width sensor 623 is provided at the bottom of the carriage, which will be described later, and can detect the paper width of the recording paper being conveyed.

The paper feed roller 606 conveys the recording paper onto the platen 608 in response to the recording operation by the recording head, for example, one line at a time recorded by the recording head, thereby recording two images of characters, etc. on the recording paper. . At this time, the recording paper is urged toward the platen 608 by the paper presser plate spring 621, so that the recording area of the recording paper can be kept flat.

The recorded paper is discharged onto a paper discharge tray by a paper discharge roller 609.

As is clear from FIG. 2(A), the recording paper conveyance path from the paper feed tray 601 shown above to the paper ejection roller 609 and further to the paper ejection tray 2009 shown in FIG.
Since it is shaped like a letter, the stiffness of the recording paper allows the recording paper to come into close contact with the platen 608, thereby making it possible to keep the recording area on the recording paper flat.

In FIG. 2(A), 1 is a recording head section, and a third
It is equipped with four recording RAD chips corresponding to each ink color detailed in the figure. These head chips are attached to the carriage body 201 of the carriage section 200 so that they can be easily attached and detached. 203 is a carriage cover, and
205 is a head cover. By attaching these covers to the carriage body 201, the electrical connection to the recording chip and the positioning of the chip are performed.
Fixation etc. are done. In addition, 300 is the carriage main body 20
1. The sub-ink tank 300 collects air bubbles in the ink supply system and buffers pressure fluctuations that occur in the ink supply system as the carriage moves. It is possible to prevent the recording head from being affected by the fluctuation.

The above-mentioned recording head unit 1 and other elements mounted on the carriage body 201 are arranged so that the carriage body 201 is attached to a guide shaft 213 (only its cross section is shown in FIG. 2(A)).
A belt that is slidably engaged with the guide shaft 213 and connects the carriage main body 201 and a portion thereof is driven by a carriage motor (not shown), thereby making it possible to move along the guide shaft 213.

Further, in FIG. 2 fA1, reference numeral 211 is a position lever whose position can be changed manually by the operator, and one end of which can be freely rotated by a shaft 211C provided in a part of the carriage body 201. Pivotally supported. Further, the other end of the position lever 211 is provided with a hemispherical convex portion 211B, which is connected to the carriage portion 211B.
The position lever 211 can be fixed in three positions by engaging with three recesses formed in the side plate (not shown) of the 00. The position lever 211 is
When the carriage main body 201, that is, the recording radar chip mounted thereon is in the positions ■ and ■ shown in l, the guide shaft 2
13 as a rotation axis, and assumes a position according to the abutment between the position lever 211 and the carriage rail 613.

That is, the position lever 211 shown in FIG. 2(A)
In this positioning process, as shown in detail in FIG. 3, a portion of the carriage body 201 comes into slidable contact with the upper surface of the carriage rail 613. In this abutting relationship, the recording RAD tip is located relatively close to the platen 608.

On the other hand, when the position lever 211 is at position (2), the holding member 211A provided integrally with the position lever 211 comes into contact with the upper surface of the carriage rail 613. As a result, the carriage main body 201 uses this contact area as a point of action and also uses the guide shaft 213 as a fulcrum to rotate with the upward force shown in FIG. take a position.

In the configuration of the position lever shown above, for example, when recording paper with relatively poor ink absorption characteristics is used, by setting the lever 211 to position 2, the RAD tip for recording is spaced relatively far from the platen 608. This is because, in the above case, the recording paper may cause phenomena such as waving due to ink from recording, and this may cause problems such as the recording paper rubbing against the recording surface and damaging the ejection orifice surface of the RAD chip. This is because by setting the lever 211 to position (3), this problem can be prevented from occurring. Furthermore, when recording paper having relatively excellent ink absorption characteristics is used, such consideration is not necessary, and the position lever 211 may be set to position (2).

Further, the position (2) of the position lever 211 is such that when the carriage section 200 is at the home position, the carriage section 200
This is the position to prevent 00 from moving to the right. That is, as shown in FIG. 2 [B], the latching hole 613B provided near the left end of the carriage rail 613
The protrusion 21 provided at the tip of the position lever 211
10 is engaged, and movement of the carriage portion 200 (not shown in FIG. 2 FB+) to the right is prevented.

Note that the position of the position lever 211 can also be notified by display or sound.

That is, as mentioned above, the position of the position lever 211 is manually changed by the operator of this device, and for example, if the carriage unit 200 is at the home position and the position lever 211 is forgotten to be at position (2). If an attempt is made to record without changing the position, a message may be displayed indicating that the position lever will be released.

Also, depending on the three positions of the position lever 211,
The current position of the position lever 211 may be displayed.

Furthermore, when the device is subjected to more than a predetermined amount of vibration during transport, etc., the system detects this and at the same time detects the position of the position lever, and if this is position ■, that is, the position where the carriage part is not fixed, a message will be displayed. may be announced by a sound such as a buzzer.

According to this configuration for preventing carriage movement, it is possible to prevent accidents such as unnecessary movement of the carriage section 200 and recording head section 1 during transportation of the present recording apparatus, and damage to these and other parts of the apparatus. can.

In FIG. 2fA), 230 is a cover fixed to the apparatus frame, and is an ink supply tube that follows the carriage part 200 as it moves.

Protect flexible cables, etc.

In Figure 2 fA) and fB), at 9018, 9
01G901M and 901Y are ink cartridges installed in the ink supply unit described later, and the ink colors are black (BK), cyan (C), magenta (M
), an ink bag for storing yellow (Y) ink, and a waste ink bag for storing ink discharged by ink suction in ejection recovery processing. An ink absorber 911 is provided at the bottom of the ink supply unit to which the ink cartridge is attached. The ink absorber 911 has a restoring force against external forces such as pressure, and is inserted in a compressed state between the recess of the frame 913 forming the supply unit and the bottom plate 2015 forming the apparatus frame. Thereby, even if ink leaks from the ink cartridge 901, it can be absorbed by the absorber 911. In addition, vibrations caused by the drive of the motor transmitted through the bottom plate 2015 and the like can be absorbed by the absorber 911, thereby reducing noise caused by the drive of the device.

Note that the absorber used for absorbing vibrations does not necessarily need to be disposed at the bottom of the ink supply unit as in the upper part, but can be disposed at a more effective location for reducing device noise.

FIG. 3 is a sectional view of the carriage section 200 and the head section 1 showing details of the recording head section 1 mounted on the carriage main body 201 described above.

In FIG. 3, lO is a recording radar chip provided corresponding to each of the four colors of ink, and since there are four in the direction perpendicular to the diagram, only one is shown in the cross-sectional view of FIG. It can be done. The head chip 1O has the shape shown in the same figure and is connected in such a manner that a substrate made of 81 is laminated on a plate-shaped base made of 1, and furthermore, a substrate made of 81 is stacked on the Si base substrate. An electrothermal transducer for generating an electric current, electrode wiring for supplying power thereto, and a head driver for driving the electrothermal transducer according to a recording signal are formed on this substrate. A top plate having a concave portion for forming an ejection port, a liquid path communicating therewith, and a common liquid chamber for supplying ink to the liquid path is joined with the concave portion inside, thereby allowing the RAD chip 10 to be used for recording. is configured. The recording radar chip of this example has 64 ejection ports on its front surface where the ejection ports are provided. A front plate 11 having openings corresponding to the areas where these ejection ports are provided is disposed on the front side of the recording RAD tip IO. The electrothermal converter is disposed in the ink liquid path communicating with each of these ejection ports, and the electrothermal converter generates heat in response to the application of electric pulses to cause film boiling in the ink. Ink is ejected from the ejection port based on the generation of bubbles due to this film boiling.

The carriage cover 203, which constitutes one of the mounting members for the recording RAD chip 10, has a connector 207 for electrical connection with the electrical wiring terminal of the recording RAD chip 10.
Four pieces are held together according to the RAD chip lO for recording, and when the cover 203 is attached, that is, from the state where the cover 203 is removed as shown by the two-dot chain line in Fig. 3, by linear movement. Connectors 207 connect RAD chips 10 to their respective corresponding records during the attachment state shown by solid lines. This connection is to the recording head chip IO
This is done by inserting the terminal into the recess of the connector 207.

At this time, the four recording RAD chips 10 are attached to predetermined positions of the carriage body 201 in an accurately positioned state, and the connectors 207 are connected along these positions. Therefore, the insertion opening of the recess of the connector 207 is formed in an R shape so that the terminal can be inserted smoothly.

The operation of the carriage cover 203 is shown in Figure 2FA)
As shown in FIG. 2, the movement of the carriage body 201 is guided by engagement of a long hole 223 formed in a part of the carriage cover 203 with a shaft 221 provided on the carriage body 201. This carriage cover can particularly protect the recording chip and its terminal portion.

FIG. 4 (A'l to fc) is a diagram for explaining how to attach the recording/rad chip 10, and the figure fA) is a front view of the carriage body 201 and the recording head 10, B) is a side partial sectional view of the carriage body 201;
Figure fcl is a perspective view of the recording chip 10.

In these figures, reference numeral 15 denotes a guide groove formed in the recording head 10, and when the head chip 10 is mounted, a guide 21 is provided in the head mounting portion of the carriage body 201.
5. Reference numeral 13 denotes an ink supply pipe for supplying ink to the common liquid chamber in the recording RAD chip 10, and when the above-mentioned mounting operation is performed, the carriage main body 20
It is inserted into the supply port 219 provided in 1. With this configuration, from the sub-ink tank 300 to the supply tube 31
1. Ink is supplied to the common liquid chamber via the supply port 219 and the supply pipe 13.

The attachment of the recording RAD chip 10 to the carriage body 201 will be explained with reference to FIG. 4(A).

When installing the head chip 10, first, the guide groove 15 of the head chip 10 engages with the guide 215 on the carriage side, and the head depth 10 is moved in accordance with this engagement.
is moved downward, and the supply pipe 13 is inserted into the supply port 219 on the carriage side. The supply pipe 13 can be smoothly inserted into the supply port 219 by the guide. Then, this movement is stopped when a part of the bottom of the Herad tip 10 hits a part of the bottom of the head mounting part on the carriage side. At this time, a part of the head chip IO is inserted into a recess formed in the carriage body 201, as shown in FIG.
The position of the discharge direction is determined. Thereafter, the positions of the RAD chips for individual recording and the pitch between these chips are determined by mounting the head cover 205 as detailed in FIG.

FIGS. 5(A) to 5(C) are diagrams showing the details of the head cover 205. FIG. 5(A) is a front view of the head cover seen from the back side, FIG. Figure (C1
is a partial cross-sectional view seen from above.

The positioning of the head chip IO by the head cover 205 will be explained below in FIGS. 3, 43 (A) and 5 (
This will be explained with reference to A) to (C).

As explained in FIG. 4, the head cover 205 is attached to the recording chip 10 attached to the carriage main body 201, and the recording chip is attached to the recording chip 10 as shown in FIG.
It is attached to the carriage main body 201 so as to cover the side part of the O. By this attachment, the leaf springs 221 and 223 of the head cover 205 shown in FIGS. 3 and 5 use their elastic force to push the head chip 10 as shown in FIG.
It is pressed toward the reference surface 217 shown in Al and the bottom surface 221 of the head chip mounting section shown in FIG. 4 fA+. As a result, the recording RAD chips 10 are arranged in the array direction (the fourth
The positioning is performed in the horizontal direction in FIG. At this time,
The four reference planes 217 and the bottom surface 221 shown in FIG.
By attaching the head cover 205, the pitch between the ejection port rows of each head chip and the above-mentioned vertical positional relationship are accurately determined.

FIG. 6 is a sectional view showing another embodiment of positioning using a head cover.

As shown in FIG. 6, instead of the leaf spring 221 shown in FIG. 5, the head cover 205 is provided with a leaf spring 225 corresponding to each recording RAD chip. The leaf spring 225 is attached to the end of the head cover 205, and presses the chamfered portion of the head chip 10 when the cover 205 is attached. Thereby, this pressing force generates component forces in the ejection direction and the ejection port arrangement direction, and positioning in each direction in the head chip IO can be performed.

FIG. 7 (Al and fB) are perspective views showing details of the sub-tank 300 shown in FIG. 2 (A), etc., and FIG. The same figure (B) shows the surface on the opposite side.

Moreover, FIG. 8 is a partial perspective view showing the sub-tank in an exploded manner.

As shown in these figures, the sub-tank 300 consists of three parts. That is, a tank member 331 for forming an ink chamber and an air chamber. Intermediate plate 33 with connecting holes formed
3. and a connecting plate 33 in which a connecting groove and a connecting pipe are formed.
Consists of 5. Each of these members can be obtained, for example, by molding a resin material, and the members can be joined by ultrasonic welding.

The tank member 331 has four chambers 3 corresponding to each color of ink.
318, 331C, 331M, and 331Y.

The middle plate 333 has, as shown in detail in FIG.
Connecting holes connecting each chamber of the tank member 331 and the connecting groove of the connecting plate 335 are formed, and among these connecting holes, reference numeral 34
1 is the connecting pipe 321 shown in Fig. 7 fA).
The one designated by the reference numeral 343, which is connected to the connecting pipe 323 shown in FIG. It constitutes a part of the flow path of the air sucked from each of the above chambers by the suction force of the unit.
Although not shown in FIG. 8, connecting holes forming part of the ink supply path to the head chip IO are formed corresponding to the positions of the respective connecting pipes 325 shown in FIG. 7(A).

The connection plate 335 has, as shown in FIG. 7fAl,
Three types of connecting tubes are formed. That is, the connection tube 321 is connected to the ink supply tube from the ink cartridge 901 described above, and the connection tube 323 is connected to the suction pump of the ejection recovery unit, and the connection tube 325 is connected to the ink supply tube from the ink cartridge 901. The ink supply tube to the recording Radchip IO is connected to the connecting tube.

Furthermore, the arrangement of the connecting pipes is determined as follows. As shown in FIG. 4 (Al and (Bl), first, the sub-tank 30 is
0 is attached so that its elongated direction is along the arrangement direction of each recording head. At this time, each of the connecting tubes 325 is arranged on the connecting plate 335 so as to be located below the RAD tip IO to the corresponding record. As a result, the ink supply tubes 311 that connect the respective connecting tubes 325 and the RAD chips 10 to each record can smoothly supply ink by simply bending within the plane of the figure, as shown in Figure 4 (Bl). Furthermore, since the direction of bending of the tube 311 is limited to within the above-mentioned plane, the influence of the carriage movement on the ink supply can be reduced. Considering the shortest route from to each connection chamber and the influence of carriage movement, the installation position of the connection pipe 325 is as shown in Fig. 7 f.
As shown in Al, the positions are arranged in the longitudinal direction of the sub-tank 300. Therefore, connecting holes are provided in the intermediate plate 333 at positions corresponding to the respective connecting pipes 325 as described above.

The arrangement of the connecting pipes 321 and 323 is determined as follows.

First, the tubes connected to these connecting tubes are
The position of the connecting tube is determined along the longitudinal direction of the sub-ink tank 300, that is, along the moving direction of the carriage section indicated by arrow A in FIG. Second, the arrangement of the connecting tubes is determined so that the tubes corresponding to each of the four colors of ink are integrally connected to the connecting tube. Based on the above first and second arrangement conditions, the connection pipes 323 and 325 are arranged in a direction perpendicular to the direction of movement of the carriage, respectively.

In addition, each ink chamber 3 of the sub-ink tank 300
The shape of the sub-ink tank and the position of the connection hole, which will be described later, are taken into consideration so that the amount of ink and air in 31Y, M, C, and Bk are the same for each ink color.

The setting of the ink amount and air amount in each ink chamber of the sub-ink tank will be described below.

Ink is supplied to the RAD chip IO for recording by utilizing the water head difference between the ink in the sub-ink tank 300 and the ink in the recording head, and by balancing this water head difference with the surface tension of the ink near the ejection 80. be exposed.

In addition, from the ink tank 901 to the sub ink tank 300
Ink is supplied to the ink supply path by a pump action caused by centrifugal force generated within the ink supply path when the ink supply path between the two operates as the carriage moves.

In the ink supply system as described above, the sub tank 300
An ink portion and an air portion are formed in each ink chamber, and the proportion of these in the ink chamber is set depending on the position where a connecting hole, which will be described later, opens in the ink chamber.

That is, air is sucked from the ink chamber through one of these connecting holes by a suction pump, which will be described later, and ink is introduced into the sub-ink tank accordingly. Therefore, when the liquid level of this ink reaches the position of the connection hole for air suction, the ink is suctioned and the height of the ink liquid level does not rise above this position.

In this way, the air portion formed in the ink chamber is provided to buffer the pressure fluctuations caused by the pumping action in the ink supply system that occurs as the carriage moves, and thereby prevents the pressure fluctuations from being recorded. This can prevent the ink from propagating to the head and adversely affecting ink ejection.

However, in an inkjet recording device equipped with multiple ink tanks according to each ink color, as in this example, the positional relationship between the ink tanks and sub-ink tanks that are set according to each ink color determines the The water head difference that occurs between the two may be different. For example, Bk,
The ink tank corresponding to each ink color of C, M, and Y is Bk.
In a device where the ink chambers of the sub-ink tanks are arranged horizontally, the sub-ink tanks are stacked vertically in this order with the sub-ink tanks stacked on top in this order. This creates a water head difference between the ink tank and the ink tank.
The water head difference between the ink tank of ink Bk and the sub-ink tank becomes the smallest. Note that this water head difference between tanks is a water head difference in a negative direction with the direction in which ink is supplied to the recording head as a positive direction, and generally speaking, the water head difference between the tanks is a water head difference in a negative direction with the direction in which ink is supplied to the recording head as the positive direction. The pressure variation due to the action is the same for each ink color.

In such a case, assuming that the volume of the air space in the sub-ink tank is the same for each ink, the influence of the pressure fluctuation due to the pump action is most noticeable for ink Bk, as shown in Section 7 (C). becomes.

In other words, this pressure fluctuation may not be completely buffered in the air section, and in such a case, this fluctuation will reach the inside of the recording head, causing its internal pressure to be in the positive direction, causing effects such as making ejection unstable. bring.

One configuration to prevent this is to change the volume of the ink amount and air amount in each ink chamber according to the difference in water head between the ink tank and the sub-ink tank for each ink color. This is possible, but in this case, problems arise such as the shape of the sub-ink tank becoming complicated.

From the above viewpoint, in this example, as shown in FIG. 1, by arranging each ink tank 901 in the horizontal direction in the apparatus, the water head between the ink tank and the sub-ink tank is reduced between each ink color. The difference is the same, and the amount of ink and the amount of air in the ink chamber are the same for each ink color, as shown in FIG. 7(B).

The recording head used in this embodiment has, for example, 64 discharges 80 lined up at a pitch of 1/360 inch, and the diameter of the discharge ports is approximately 600μ. Further, the acceleration of the carriage up to the printing area is 3.6 mm/sec'', and the distance from the ejection opening at the bottom of the recording head to the center of the main tank is 50 mm.

In this configuration, the height from the lowest ejection port to the ink level in the sub-tank on the carriage is 25 mm.
In this case, a preferable result has been obtained in which the amount of air in the sub-tank divided by the amount of ink stored in the sub-tank is 1 or more. However, the amount of ink stored in the sub tank at this time is 0.5cc or more1
．． This is a case of 5cc or less.

With the above configuration, it is possible to effectively buffer pressure fluctuations in each ink chamber of the sub-ink tank and prevent the pressure inside the print head from becoming a positive pressure. can be made concise.

FIG. 1O is a top view showing the tube unit connected to the connecting pipes 321 and 323.
joints 351 and 353 respectively connected to 23
is shown. These tubes 355 and 357 follow the movement of the carriage in the direction shown by arrow C in the figure, and the arrangement of the connecting tubes shown above allows the tubes to be moved in a fixed direction (carriage movement direction). In this trailing portion of the tube, the tube only bends in certain directions. This makes it possible to reduce the influence of carriage movement on ink supply and the like.

According to the arrangement of the connecting pipes 321 and 323 shown above, grooves 337 and 339 as shown in FIG.
31 (BK, C, M, Y) are connected.

FIG. 9 is a sectional view showing another embodiment of the sub-ink tank 300. As shown in the figure, grooves for connecting each tank chamber and the connecting pipe can also be formed in the middle plate 333.

Figure 11 (A) and (B) are respectively Figure 2 (A)
and (B) are cross-sectional views showing details of the paper feeding mechanism shown in FIG.
B) shows the case of transporting cardboard.

In these figures, the pinch roller 607 is rotatably supported by a pinch roller holder 611, and the pinch roller holder 611 rotatably engages with the carriage rail 613 at an end 611B. Further, a spring 614 is inserted between the pinch roller holder 611 and the carriage rail 613, and the carriage rail 61
3 is biased downward in FIG. 11 by springs 631 hooked to hooks 613B at both ends thereof, as shown in FIG. It is being As a result, the pinch roller 607 can press the paper feed roller 606 due to the elastic force of the spring 614.

In the above configuration, as shown in FIG. 11(A), when relatively thin recording paper is conveyed, the pinch roller 6
The displacement of the pinch roller 607 caused by the thickness of the recording paper between the recording paper 07 and the paper feed roller 606 is absorbed by only the pinch roller holder 611 being displaced upward in FIG.

On the other hand, as shown in FIG. 11(B), in the case of relatively thick recording paper, the pinch roller 60 due to the thickness of the paper
The displacement of 7 cannot be completely absorbed by the rotational displacement of the pinch roller holder 611, and the pinch roller holder 611 further displaces in accordance with the displacement of the pinch roller 607 and abuts its end 611A against the carriage rail 613, thereby releasing the spring. Push it up against the elastic force of 631. That is, the displacement of the pinch roller 607 when relatively thick recording paper is conveyed is absorbed by the displacement of the pinch roller holder 611 and the subsequent displacement of the carriage rail 613.

At this time, the carriage rail 613 moves along the carriage main body 201 according to the position of the position lever 211 described above.
Alternatively, since it is in contact with the pressing member 211A, the carriage section 200, that is, the recording head section 1 is displaced in accordance with the displacement of the carriage rail 613.

According to the paper feeding mechanism described above, when the recording paper used is relatively thin, the pinch roller 607 feeds the paper through the recording paper by displacing the pinch roller holder 611 and applying an appropriate pressing force depending on the paper thickness. The roller 606 can be acted upon.

Also, if the recording paper is relatively thick, use the pinch roller holder 6.
11 and the carriage rail 613, the pinch roller 607 can apply an appropriate pressing force to the paper feed roller 606 according to the paper thickness, and
The distance between the recording paper and the recording head can be set appropriately depending on the thickness of the paper. It goes without saying that the paper feeding mechanism described above operates effectively regardless of the position of the position lever 211 (E or ■).

The configuration and operation of the paper feeding device according to the present invention will be described in detail with reference to FIGS. 12(A) and 12(B). In addition, in FIG. 12(A), the recording paper is a thin sheet 610A.
In the case of FIG. 12(B), the recording paper is a thick sheet 610B.
The behavior of the separation plate 605 in the case of the following is shown.

In these figures, 651 is a loosely fitting groove for supporting the separation plate 605 provided in the support member 603 that forms part of the device frame, and the opening direction of the groove 651 is approximately oriented toward the center of the axis of the pickup roller 604. It is formed like this.

The separation plate 605 also has a spring 612 held between the spring holding portion 605A and the bottom of the loose fitting groove 651, and hook-shaped claw portions 605B extending downward from both sides of the spring holding portion 605A. These claws 605
B is fitted into the engagement hole 651A provided at the bottom of the loose fit groove 651, thereby preventing the separation plate 605 from falling out of the loose fit groove 651. With the above configuration, the separation plate 6
05 is supported by the spring 612 and fits into the loose fitting groove 651.
This allows for internal swinging and vertical movement. Note that the spring 612 is selected to have an appropriate spring constant depending on the expected stiffness range of the recording paper used for recording.

In the paper feeding device configured as described above, FIG.
As shown in A), a thin sheet 610A that is relatively weak as a recording paper is placed in a feeding cassette, that is, a paper feeding tray 60.
Suppose that it is stored in 1. When the pickup roller 604 is driven by the feed signal in this state, the feed cassette 6
The thin sheet 610A located at the uppermost surface on 01 is sent out. First, the tip of the sheet 61OA is
It comes into contact with the separation plate 605.

In response, the separation plate 605 is displaced to a position corresponding to the stiffness of the thin sheet 610A and the spring force of the spring 612 supporting the separation plate 605, and the approach angle of the thin sheet 610A to the separation plate 605 ( The angle between the recording sheet entry direction and the plane of the separating plate can be set to the optimal angle.
It is possible to improve the conveyance force (frictional force) generated between the half-moon roller 604A and the recording sheet.

In addition, when a thick sheet 610B with relatively strong stiffness is stored in the feeding cassette 601 and fed as shown in FIG. 605, the separating plate 60
5 is pushed down, its shoulder 605C hits the bottom of the groove 651, and it rotates using this shoulder 605C as a rotation fulcrum. As a result, the angle of approach formed between the recording sheet and the separation plate 605 can be made smaller than that shown in FIG. It is possible to prevent the conveyance force (frictional force) from becoming excessive and avoid paper feeding failures in the case of thick paper.

(Recovery Unit) FIG. 13 shows a schematic configuration of a recovery unit 400 according to this example.

Here, 401 is a unit casing, and the following parts are held in this unit casing 401. 403
is the driving source for each part of the unit,
Driving force is transmitted to the worm wheel shaft 411 via a worm 407a attached to the motor output shaft 405 and a worm wheel 409 meshing with the worm 407a.

Reference numeral 420 denotes a cap portion that can come into contact with the ejection orifice forming surface lA of the recording head 1 to cover the ejection orifice periphery, and at least the portion that contacts the ejection orifice forming surface is formed of an elastic member such as rubber. Reference numeral 430 denotes a cap press-contact/equalization part for press-contacting the cap part 420 with the discharge port forming surface IA and ensuring a close contact state by conforming to the cap part 420. 440 is a pump, and the suction tube 4 communicates with the cap portion 420.
42 and the aforementioned sub-tank 300 through a suction tube 444 that communicates with the sub-tank 300, a suction force is applied to each of them, and the ink is sucked into the waste ink absorber (not shown) in the ink tank through a waste ink tube 446. discharge. This pump 440 is driven by a pump drive cam 450 provided on the shaft 411 and a pump drive lever 452 engaged with the pump drive cam 450.

In this example, the tube 442 that communicates between the cap portion 420 and the pump 440 is bent vertically upward from the in-cap communication hole 442A to which the tube 442 is connected, and is then connected to the pump 440 located below. It looks like this. As a result, after ink is suctioned from the ejection port via the cap part 420, if suction processing (empty suction) is not performed in the uncapped state or is not performed sufficiently, a small amount of ink can be sucked into the tube 440. remain within. That is, the presence of the bend prevents all ink from flowing into the pump. By utilizing this, for example, the ejection port forming surface IA can be kept in a moist atmosphere in the capped state when recording is interrupted or when recording is stopped.
It protects the discharge port from drying out and prevents clogging. Therefore, it becomes possible to make the bow processing unnecessary or minimal when recording is resumed. In addition, when the ink is not in use for a long time or the power is turned off, sufficient empty suction is performed to prevent ink from remaining in the tube, thereby preventing the ink from sticking in the tube.

In addition, in this example, when the unit 400 is attached to the device, the discharge side of the pump 440 is located at the bottom in the vertical direction, and the discharge flow path is arranged so as to face downward. The ink is discharged smoothly under the influence of gravity.

FIG. 14(A) is a side sectional view of the recovery unit 400. Here, reference numeral 461 denotes an access lever whose tip 461A enters a recess 205H provided in the recording head cover 205 to directly face the cap portion 420 to the ejection port formation surface IA, and at least its tip portion is used for scanning the recording head. It can be displaced or deformed in the direction (perpendicular to the drawing). 465 is an access lever drive arm;
It is coupled with the access lever 461. This arm is also rotatable around an axis 465A near one end.

A cam 467 is provided on the shaft 411 and engages with a pin 468 on the arm 465. 469 is a spring for regulating the movement of the arm 465 by making the bottle 468 conform to the contour of the cam 467;
The arm 46 is stretched between the protrusion 463 provided on the arm 46
5 is given the ability to rotate toward the cam 467 side.

471 is a cap holder that holds the cap portion 420;
473 is a holder guide lever provided integrally with the cap holder 47-1, and its tip 475 is connected to the housing 40.
It protrudes through the hole made in 1.

The cap holder 471 can move forward and backward with respect to the recovery unit 400 while holding the cap part 420, and as the cap holder 471 moves forward, the cap part 420 comes into contact with the discharge port forming surface IA, and as it retreats, this contact is released. In addition, the cap part 4
20 to the cap holder 471 are movable in the recording head scanning direction.

Reference numeral 477 is a spring for making the holder-side engaging portion move against the cam that restricts the forward and backward movement of the cap holder 471, and is provided at the tip end portion 475 of the holder guide lever.

The cap portion 420 is provided with an atmospheric communication hole, which will be described later.
This communication hole is also opened and closed via a cam 513, a drive lever 511, etc., which will also be described later. The opening/closing mechanism of this atmospheric communication hole, the advancing/retracting mechanism of the cap portion, the advancing/retracting mechanism of the access lever, etc. will be described later with reference to FIGS. 15 to 17.

In FIG. 14 (Al), reference numeral 481 is a locking portion for obtaining a locked state between the recovery unit 400 and the carriage portion 200 during recovery processing and the like.

Further, in this example, the pump 440 is provided in the housing-side pump receiving portion 4.
Holder 48 as shown in FIG. 14(B) provided in 01A
It is held at 3. This holder 483 has a substantially C-shape, and holds the pump 440 by its elastic deformation and restoring force. Note that 491 and 493 are locking portions on the housing side and the pump side, respectively, and are used for positioning the pump 440 and maintaining the mounting position.

Fig. 15 is a perspective view of the recovery unit centered on the opening/closing mechanism of the atmospheric communication hole in the cap, and Fig. 16 is a side cross section of the recovery unit centered on the opening/closing mechanism, the cap movement mechanism, and the access lever movement mechanism. It is a diagram.

First, the atmospheric communication mechanism will be explained.

In these figures, 501 is an atmosphere communication hole of the cap portion 420. Reference numeral 503 denotes an opening/closing lever, which includes an arm portion 503A provided with a pad 505 for closing the atmosphere communication hole portion 501 and an arm portion 503 that engages with the operating lever 511.
B, and is rotatably supported around a shaft 507. Reference numeral 509 is a spring for giving the opening/closing lever 503 the ability to rotate in the direction of closing the atmospheric communication hole.

The operating lever 511 includes a portion 511A that engages with the communication hole opening/closing cam 513 and an arm portion 503B of the opening/closing lever 503.
It has a portion 511B that engages with, and is rotatable around a shaft 515. Reference numeral 517 denotes a spring, which gives the actuating lever 511 a turning habit in the direction in which the portion 511A comes into contact with the cam 513. As a result, as the cam 513 is displaced, the space inside the cap portion 420 is communicated with/cut off from the atmosphere.

Next, a mechanism for advancing and retracting the cap portion 420 will be described.

In FIG. 16, the cap holder 471 and the holder guide lever 473 are indicated by two-dot chain lines. 521
is a roller provided on the holder guide lever 473, which engages with the cap advancing/retracting cam 523.

531 is an elongated hole provided in the elongated direction of the access lever 461, into which a pin 533 protruding from the cap holder 471 is inserted. Therefore, in this example, the cap portion 420 is guided by the elongated hole 531 during forward and backward movements.

Further, it is interlocked with the access lever 461 in the recording head scanning direction. A spring 535 cooperates with the spring 477 to bias the cap portion 420 in the backward direction. Further, 205H is a recess provided in the recording head cover 205 to receive the entry of the access lever 461.

Note that in FIG. 16, the access lever drive arm 465 is shown in a different position from that in FIG. 14 to simplify the illustration.

Next, the forward and backward movement of the access lever 461 and the cap portion 420 will be described.

In general, it is difficult to precisely stop the carriage at a position where the recording head ejection orifice forming surface and the cap are directly facing each other. Therefore, for example, a member that can protrude toward the recovery unit side is installed on the recording head side. It is possible to forcibly set the carriage in a position where the recording head side directly faces the cap by providing a receptive member and forcing the former into the latter. However, a carriage like this example has four recording heads. The head is mounted and has a large weight, and forcibly displacing it as described above not only requires a large amount of force, but also causes an excessive load on the thrusting member, cap, etc. It can also lead to

Therefore, in this example, a configuration is adopted in which the cap portion 420 side is displaced so as to directly face the recording head ejection port forming surface.

This will be explained using FIGS. 17(A) to (C).

First, the arrangement range H of the four recording heads to be covered by the cap parts and the arrangement range C of the four cap parts each covering the ejection orifice forming surface of the recording head separately are set as shown in FIG. Suppose that the carriage deviates by a certain amount and then stops.

When the access lever 461 is protruded from this state, the tapered portion 461■ of the tip portion 461A eventually engages with the recess 205H of the head cover 205, and the access lever 461 is supported so as to be displaceable in the carriage scanning direction S. If so, it will move to the left in the figure and then enter the recess 205H, as shown in FIG. Moreover, the leftward movement is caused by the bin 533 and the elongated hole 531.
Since they are engaged with each other, the cap holder 471 or the cap portion 420 are displaced in the same direction.

Therefore, in the state shown in FIG. 4C in which the access lever tip 461A has completed entering the recess 205H, there is no deviation between the range H and the range C, that is, the recording head and the cap portion 4
20, so that accurate capping can be performed by advancing the cap portion 420.

In this example, strict accuracy is not required regarding the different stop positions of the carriage, but the access lever can enter the recess as long as a certain degree of accuracy is secured. Conversely, the first dimension of the access lever tip shape, the fifth dimension of the recess shape, etc. are selected depending on the accuracy of the carriage stop position.

In order for the tip of the access lever to enter smoothly, the entire access lever must be attached to the housing so that it can be displaced in translation in the scanning direction S, as described above, or it must be centered around the rear swing fulcrum. be attached to the housing such that it can be oscillated, and furthermore, at least the tip portion 4
61A may be elastically deformable to some extent, or a combination thereof may be adopted. In any case, it is sufficient that the elongated hole 531 constitutes a path for guiding the cap portion 420 to a predetermined position (accurate cap position) via the bottle 533 when the plunge is completed. For example, if the access lever 461 is swingable about the rear fulcrum, unlike in FIG. 17, the access lever 461 will be tilted when the entry is completed, and the ranges H and C will not face each other when the cap is not on. However, since the elongated hole 531 is also inclined, if the bottle 533 moves forward along this elongated hole 531, the cap portion 420 will eventually be able to accurately cover the recording head ejection opening forming surface.

Access lever 4 due to such entry on the cap side
In order to be able to follow the displacement or deformation of the elongated hole 61 or the elongated hole 531 without restricting it, and to be able to move forward and backward along the elongated length of the elongated hole 531, the cap part itself must be It is preferable to attach it to the housing with some play.

In addition, in FIG. 17 (A1-(C)), 540 is a blade, which can move forward and backward by a cam provided in the recovery unit 400 like the above-mentioned parts, and moves the recording head according to the carriage scanning in the protruding state. It engages with and cleans the discharge port forming surface.

Figures 18(A) to (C) show the pump 4 used in this example.
40 configuration examples are shown.

Pump 440 has a cylinder body 551, cylinder heads 553 and 555, a piston 557, and a valve unit 559. The valve unit 559 is attached to the cylinder head 553 on the bar side, and the cylinder head 553 has a portion 56 that is snap fastened to a protrusion 561 on the cylinder body 551.
3, thereby making it possible to easily attach the valve unit 559 and cylinder head 553.

The valve unit 559 includes a valve element 565 that can open and close the ink inlet from the cap side and the sub-tank side, and a spring 567 that biases the valve element in the closing direction.

The piston 557 is arranged between a piston shaft 557A in which a flow passage 556 is formed in a part, a valve body 571 and a flange portion 573 provided on the piston shaft 557A, and the valve body and the flange in a loosely fitted state on the shaft 557A. , and a frame 570 having an ink flow path 570A formed therein. Further, the cylinder head 555 has a sealing portion 555A,
Similar to the cylinder head 553 above, the cylinder body 55
Attached to 1.

In such a configuration, when the piston 557 is displaced downward in the figure as shown in FIG.
opens the ink introduction port, thereby suctioning ink from the cap side and the sub-tank side, and since the valve body 571 closes the flow path 570A, the ink in the lower chamber flows through the pipe portion 575 without causing backflow. is discharged through. Thereafter, as shown in FIG. 5C, when the piston 557 is displaced upward, the valve body 571
is opened, and the ink stored in the upper chamber flows into the flow path 57.
0A and 556 into the lower chamber.

Further, at this time, since the valve body 565 closes the ink inlet, ink does not flow back to the cap side and the sub tank side.

The pump 440 configured and operated as described above is attached to the recovery unit housing 401 using a holder as shown in FIG. 14(B). In addition, in this example, the piston 44
A total of four 0's are provided, one per l cap, that is, one recording head. This has the following advantages:

In the case of this example, four recording heads are provided corresponding to inks of different colors (yellow, magenta, cyan, and black). However, the amount of ink to be sucked during recovery processing varies depending on the frequency of use, ink composition, etc. of each recording head.

Therefore, if a pump is used in combination, and assuming that approximately the same negative pressure acts on each head, it is necessary to use a pump whose capacity is determined in accordance with the amount of ink sucked from the recording head that requires the most ink consumption. This not only increases the size of the pump, but also causes more ink to be suctioned from the recording head, which requires less consumption during recovery processing.

On the other hand, in this example, the capacity of each pump can be determined in accordance with the amount of ink suction required by each recording head, and the inconvenience caused when the pump is used in combination can be avoided.

FIG. 19 is a conceptual diagram of the drive system of four pumps according to this example. As shown in the figure, in this example, the pump 440 has two side sets, and each set has a cam 450 attached to a shaft 471.
and lever 452. In this example, the cam phases of each set are made equal, that is, the four pumps 440 are driven in the same phase. Therefore, assembly work becomes easy.

However, the phases may be different for each set (or a cam or lever may be provided for each pump and each pump may be driven at a different phase. is preferable.

The operation timing of each part of the recovery unit such as the cam and each part driven by the cam can be determined, for example, as shown in FIG. 20. Note that in the figures, the "sensor" may be a sensor that detects the open state of the cap.

Furthermore, in the "small recovery" and "r main recovery" modes, for example, the amount of ink suction can be made different, so-called preliminary ejection can be added, etc. Further, after the recovery process, it is preferable to make the blade protrude and clean the discharge port forming surface.

Furthermore, in this example, the access lever is protruded prior to capping, and conversely, the capping is released prior to retraction of the access lever. This is because the cap portion 420 is moved back and forth along the elongated hole 531 of the access lever described above. Also, when applying capping,
and when canceling this, at any other appropriate timing,
The atmospheric communication hole of the cap portion 420 is opened. this is,
This is effective in preventing air intake into the ink discharge 80 and ink leakage due to undesirable pressure fluctuations occurring in the space within the cap when the cap is joined/separated.

(Arrangement of Ink Tanks) FIG. 21 is a plan view of the ink tank storage section of the apparatus of this example.

Here, 701 (7018, 701C, 701M
, 701Y) is an ink tank in the form of a cartridge having an ink storage section serving as an ink supply source and a waste ink storage section serving as a waste ink reservoir, and is removably attached to the main body of the apparatus.

703 (7038, 703G, 703M, 703Y
) is an ink supply pipe, which is connected to the ink storage section in the ink tank. Also, 7137 (707BK,
707G, 707) I! , 707Y) is a waste ink pipe, which communicates the pump 440 with the waste ink storage section in each ink tank.

Regarding the arrangement of ink tanks, etc., the following points were particularly taken into consideration in this example.

Due to its composition, ink has different susceptibility to thickening and sticking depending on the color. For example, black (BK), cyan (C),
Thickening and sticking tend to occur in the order of magenta (M) and yellow (Y). As a result, the ink tends to thicken and stick even within the ink supply pipe, which is a closed system. In this example, the supply tube was constructed using polyurethane tube, but whatever the material of the supply tube, a small amount of air may enter through the tube wall or the ink solvent may evaporate. Therefore, as the supply pipe becomes longer, the amount of air that enters or the amount of evaporation of the ink solvent increases.

Therefore, in this example, all the supply pipes are routed in the same direction (in this example, on the left side in the figure), and ink tanks containing ink that is likely to increase in viscosity and stick are arranged in order from the nearest to the supply side. In other words, the length of the supply tube for ink that is more likely to thicken and stick is made shorter (black, cyan, magenta, and yellow in this order from the left in the diagram). This makes it possible to reduce the amount of air entering or the amount of solvent evaporation.

Incidentally, the above also applies to the ink discharge system leading to the waste ink storage section.

In the figure, reference numeral 800 denotes an ink remaining amount pressure detecting device, which will be described next, and is arranged between the ink storage section in the ink tank 701 and the ink supply pipe 703. Also, 707
Reference numeral 709 denotes a cable that brings together wiring related to the ink remaining amount pressure detecting device 800 and wiring related to a sensor that detects whether or not an ink tank is attached, and 709 is a connector portion thereof.

(Remaining ink amount detection system) Figure 22 (A) is a plan view of the ink pressure detection device.
Figure (B) is a longitudinal cross-sectional view of the same device.

801 is a flow path member having an ink flow path 803 inside, and includes a pair of upper and lower members 801A and lower member 801B.
It consists of Upper member 801A has a circular opening 805. Reference numeral 807 is a ring-shaped diaphragm, the peripheral portion of which is held between the upper member 801A and the pressing member 809, and covers the peripheral portion of the opening 805. Upright stop members 811 are provided at the upper four corners of the upper member 801A.
are provided respectively, and through holes 813 are vertically formed in each of the four corners of the presser member 809.
A stepped portion 813A is formed on the outer side of the upper part of 13. The stop member 811 has elasticity, and a stop claw 811A is formed on the outside of the tip. The upper surface of the locking claw 811A is sloped.

Each stop member 8 is provided in each through hole +113 of the presser member 809.
11 is positioned, and the locking claw 811A of the stopper member 811 is locked to the stepped portion 813A, whereby the presser member 809 is fixed to the upper member 801A, and the diaphragm 807 is held between the upper member 801A and the presser member 809. Ru. Note that a protruding portion 881 is formed around the upper surface of the upper member 801A, and a notch 8 is formed around the lower surface of the corresponding presser member 809.
83 is formed, and by fitting them together, the pressing member 809 is positioned and fixed to the upper member 801A.

A support member 815 is attached to the center portion of the diaphragm 807 so as to close the inner opening, and a protrusion at the upper center of the support member 815 (located at the center of the opening 805) 8
The proximal end of the locking member 817 is fixed (for example, screwed) to the support member 815 so as to fit into the locking member 815A.

The locking member 817 includes two elastic locking pieces 8 that stand upright.
19, and a locking claw 8 is provided on the outside of the tip of each locking piece 819.
19A is formed. The upper surface of the locking claw 819A is sloped. Note that the two locking pieces 819 are connected to the opening 805.
are placed symmetrically from the center of the

A through hole 821 is formed vertically in the central part of the holding member 809, and two locking pieces 81 are inserted into this through hole 821.
9 is located. A coiled spring 82 is installed inside the through hole 821.
3 and a spring locking ring 825 are located, and the lower end of the spring 823 is located outside of the two locking pieces 819 through the through hole 82.
It is supported by an annular protrusion (spring receiver) 821A at the bottom of 1. The spring stop ring 825 has a locking piece 8 on the inside.
The spring 823 is prevented from being removed by the locking claw 819A of No. 19, and in this state, the upper end of the spring 823 is pushed down. The spring 823 is compressed by both (the annular protrusion 821A and the spring stop ring 825). Therefore, due to the repulsive force of the spring 823 (ignoring the pressure of ink in the ink flow path 803), the upper peripheral portion of the support member 815 is moved into the annular protrusion 821A.
The diaphragm 807 and the support member 815 are pulled upward so as to come into contact with the lower surface of the diaphragm 807 and the support member 815.

A notch 827 is formed on one side of the holding member 809, and an intermediate portion of a pair of contact members (conductive) 829, 831 is fixed to the bottom of this notch 827. The tip ends of the pair of contact members 829 and 831 are in contact with the lower surface of the annular protrusion 821A through a hole 827A formed at the bottom of the notch 827, and the rear ends are provided with a connector (for detecting the amount of ink remaining). Lead wires 835 and 837 from 833 (for connecting to the electrical circuit for the 833) are connected. A spring 823 is attached to the lower surface of the tip of the pair of contact members 829 and 831.
The upper surface of the support member 815 is pressed by the repulsive force to the upper surface peripheral portion (which has conductivity), and the upper surface of the supporting member 815 becomes electrically conductive with the upper surface of the support member 815.

The ink pressure sensing device configured as described above can be assembled very easily as follows.

First, the diaphragm 8 is placed on the opening 805 of the channel member 801.
07, and then lower the holding member 809 from above the channel member 801 so that the stopper members 811 are located in the through holes 813 at the four corners. As a result, the slope of the upper surface of the locking pawl 811A of the stopper member 811 hits the inner edge of the through hole 813 of the holding member 809, and the stopper member 811 is pushed by this.
1 tilts inward and enters the through hole 813 (that is, the pressing member 809 descends), and with the pressing member 809 pressing the diaphragm 807 from above, it enters the through hole 813.
The locking claw 1111 of the stopper member 811 is attached to the upper step portion 813A.
A moves elastically (returns to its original position) and is locked, and the pressing member 809 is positioned and fixed to the upper member 801A.

Next, the spring 823 is inserted into the through hole 821, its lower end is placed on the annular protrusion 821A, and the spring stop ring 825 is placed on the annular protrusion 821A.
is positioned above the two locking pieces 819 and pushed down. As a result, the slopes of the upper surfaces of the locking claws 819A of the two locking pieces 819 are pressed against the inner edge of the spring stop ring 825, and the two
The two locking pieces 819 are inclined inwardly to each other due to their elasticity.
The spring locking ring 825 descends, and the two locking pieces 819 are tilted outward from each other due to the elasticity again, and the two locking claws 819A are locked to the inner upper surface of the spring locking ring 825, thus preventing the spring from tightening. The retaining ring 825 is prevented from being removed by the two retaining pieces 819, and the spring 823 is compressed by the spring retaining ring 825 and the annular protrusion 821A. Note that the pair of contact members 829 and 831 are attached to the pressing member 809 in advance.

According to the above configuration, the distance between the spring stop ring 825 and the annular protrusion 821A is constant, and the spring 82
The compressive force (repulsive force) of No. 3 falls within a predetermined range. Therefore, the diaphragm 807 responds to the negative pressure within a predetermined range of the ink within the ink flow path 803, and the support member 815 opens the pair of contact members 829, 831.

Therefore, according to the ink pressure detection device of the present invention, the detected pressure falls within the range in which the remaining amount of ink is stabilized, for example as shown by arrow A in FIG. 24, without any adjustment.

Note that normally, the ink pressure in the ink flow path is detected by an ink sensor when the carriage is stopped or while the carriage is running (that is, excluding when the carriage returns). This is because, as shown in FIGS. 23(A) and 23(B), when the carriage 851 returns to the left side and returns to the right side, an inertial force acts on the ink in the ink flow path 853 as shown by the arrow in the figure, and the effect is As a result, extra negative pressure is applied to the ink in the ink flow path when returning to the left side, and extra pressure is applied to the ink in the ink flow path when returning to the right side, and the ink sensor 855
This is because the true amount of ink remaining in the ink cartridge 857 cannot be detected.

For reference, FIGS. 25(A) and 25(B) show a plan view and a vertical cross-sectional view of a conventional ink pressure detection device (ink sensor). 859 is a channel member having an ink channel 861 inside, 863 is a holding member, the diaphragm 865 is held between these members 859, 863, and the supporting member 8 is attached to the center of the diaphragm 865.
A center portion 867A of 67 protrudes into a through hole 869 at the center of the holding member 863, and a ring-shaped adjuster 871 is screwed into the upper part of this center portion 867A. The spring 873 is compressed by the portion 869A, and when the ink in the ink flow path 861 is higher than a predetermined negative pressure, the diaphragm 865Σ and the support member 867 are arched up by the repulsive force of the spring 873, and the annular protrusion 869A The peripheral upper surface of the support member 867 presses the tips of the pair of contact members 875 and 877 located on the lower surface of the support member 867 to bring them into electrical contact with each other.

According to such a configuration, when the ink in the ink flow path 861 falls below a predetermined negative pressure, the diaphragm 865 responds and the support member 867 descends, and as a result, the pair of contact members 875 and 877 The support member is separated from the tip and a predetermined negative pressure is thus detected. Therefore, the negative pressure detected by the pair of contact members 875 and 877 is caused by the spring 87
Corresponds to the repulsive force of 3.

However, in the conventional ink pressure detection device as described above, extremely troublesome adjustments must be made during assembly to bring the detected negative pressure to a predetermined value. That is, by appropriately turning the adjuster 871, the spring 87
3, the detected negative pressure value varies. For example, Figure 24 shows the relationship between the remaining amount of ink in the ink cartridge (g) and the negative pressure of ink in the ink flow path. As shown in the figure, the value of negative pressure to be detected is set to 65 ± 5 mm.
In order to make it approximately q, the pressure of the spring 873 must be finely adjusted using the adjuster 871, which is extremely troublesome.

(Supply Pipe Connection Portion) FIGS. 26(A) and 26(B) show an example of the configuration of the ink supply tube connection portion.

Here, 901 is a joint made of rubber, for example, attached to the main body frame 900, and is attached to the ink tank 7018.
~703Y is fitted into the ink supply pipe 7038 from 701Y, and ~9 is fitted into the communication pipe section 9258 described below.
It has a receiving part that receives the fitting of 25Y. This receiving part 9
03 is provided with a valve body 905 that narrows the ink flow path to such an extent that no ink leakage occurs when ~925Y is not attached to the communicating pipe portion 9258, and opens the ink flow path when it is attached.

Reference numeral 921 is a joint that is connected to the joint 901 on the main body frame 900 side to introduce ink to the recording head side, and the joint 921 has a distal end portion inserted into the receiving portion 903 of the joint 901 and a tube extending rearward. ~925Y to the communicating pipe portion 9258 having a portion, and the main body frame 900
a latch part 927 that engages with the engaging part 907 provided in the latch part 927, an operating part 929 for releasing the engaged state by opening the latch part 927 outward, and a protrusion 931 that will be described later with reference to FIG. Frame section 92 that holds these
3 are integrally formed by molding, for example, resin. A joint member 915 made of, for example, rubber is held on the frame portion 923 and has four flow paths formed therein. A communicating pipe portion 9 is provided at one end of the flow passages.
The rear extending portion of ~925Y is inserted into 258, and ~301Y is inserted into the supply pipe 3018 leading to the recording head at the other end. Further, 917 is the letters "B", "C", "M" and "Y" provided near the connection part of the joint member 915 to the supply pipe 301 by printing or pasting a sticker, and they are respectively black, 301C to supply pipe 3018 for cyan, magenta, and yellow.

This is a display to prevent erroneous connection of 301M and 301Y.

When joining the joint 921 to the joint 901, when the joint 921 is advanced in the direction of the arrow from the state shown in FIG. , and the latch portion 927 is pushed outward as the mounting operation is performed. When the surface portion 927T passes over the locking portion 907, the latch portion 927 is restored due to its spring property, and the joint 921 is locked as shown in FIG. 9(B). Also, in this state, the communication pipe portion 925 has entered the receiving portion 903 with the valve body 905 being pushed out, so that there is ink communication between both joints, that is, ink communication between the ink tank side and the recording head side. will be done.

By the way, in such a mounting operation, it is conceivable that the operator performs an erroneous operation, that is, performs an erroneous mounting operation in which the joint 921 shown in FIGS. 26(A) and 26(B) is turned upside down. In order to prevent this reliably and with a simple configuration, the following configuration is adopted in this example.

FIG. 27 is a side sectional view of the ink supply pipe connection section. In this example, the operating portion 929 and the protrusion 931 are connected to the joint 92.
1, and the operating portion 929 has a shape with a portion 943 for preventing erroneous attachment.

On the other hand, the body frame 900 is provided with a locking portion 941 that does not interfere with the portion 943 during normal mounting as shown in the figure, but engages with the portion 943 to prevent the mounting operation when the front and back surfaces are reversed and incorrectly mounted. This prevents incorrect mounting of the joint 921 with the front and back sides reversed, and prevents ink of a different color from being introduced into the recording head provided corresponding to each color.
Inconveniences such as color mixing can be prevented.

Note that the portion 943 for preventing incorrect attachment may be provided on the frame portion 923, or may be formed by extending the protrusion 931 inward of the frame portion and rising from the extending portion.

According to this example, it is possible to connect the ink supply tube without causing incorrect installation with a simple operation, but as shown in FIG.
By operating the operation part 929 from the state shown in FIG. 1, the engagement between the latch part 927 and the locking part 907 can be released, so that the joint 921 can be easily removed. Such ease of removal improves maintenance workability. Further, by this removal, the valve body 905 returns to the state shown in the figure (Al), so ink leakage does not occur.

Now, in consideration of further improving the workability of maintenance involving the removal of the joint 921, it is highly desirable not to burden the operator with paying attention to the location of the removed joint 921, etc.

Therefore, in this example, as shown in FIG.
is provided on the side plate 2017. The receiver parts 2o21 can be provided as a set in a number corresponding to the number of projections 931, but they can also be provided in correspondence with any two of the temples while maintaining balance. In addition, its location is on the side plate 20.
It can be provided at any predetermined position on 17, or it may be provided at various locations.

FIG. 28(B) shows a cross section taken along the line AA in FIG. 28(A) with the joint 921 placed thereon. In this way, the protrusion 9
31 is received in the hole 2023, and the lower end surface of the frame portion 923 is placed on the upper surface of the receiver portion 2021, so that the joint 921 is stably held. Further, in this state, the tip of the communicating tube portion 925 faces upward, so that no ink leakage occurs.

Note that various configurations for holding the joint 921 in this manner can be selected. For example, by utilizing the gap between the operating portion 929 and the protrusion 931 that appears in the side view, it is also possible to hook this onto a rod-shaped member provided on the side plate 2017 or the like, or an edge of the side plate or the like. In this case, tube 30
1, the operating portion 929 is held upside down from that shown in FIG. .

This is because even if it falls down, the extended portion engages with the side plate 2017 etc., thereby preventing further falling down.

In addition, in the above description, the ink supply system has a joint with a valve body on the upstream side in the ink supply direction, and a joint on the downstream side that opens the valve body in response to insertion, but the configuration of both joints can also be reversed. good.

In addition, such connections are not limited to the ink supply system.
Of course, the present invention can also be adopted for an ink discharge system leading to a waste ink storage section (in this example, provided in an ink tank).

(Inclination Angle of Recording Area) In this embodiment, the inclination angle that the recording area, where the recording medium and the inkjet recording head face each other with a gap in between, makes with respect to the horizontal plane is appropriately selected and determined. Let me first explain the reason.

In the recording method in which ink is ejected almost horizontally, the 29th
As shown in the figure, when a recording medium S with a slow ink absorption speed such as general high-quality paper (plain paper) is conveyed upward, when recording is performed on this recording medium S with an inkjet recording head H, the following occurs. condition was observed. That is, out of the recorded ink, the unabsorbed ink IR remaining on the surface of the recording medium S without being absorbed tends to flow downward due to gravity and become fixed on the recording medium. This is true even when using a so-called full-line type recording head in which the ejection ports are aligned over a range corresponding to the entire width of the recording medium, but especially in the case of a serial type as shown above, printing multiple times for all lines. When the scanned recorded image was examined, as shown in FIG. 30, in one scanned area, the density was lighter in the upper part and darker in the lower part, and density unevenness was observed. This problem was particularly noticeable when the amount of ink ejected by the print head was increased for the purpose of increasing the density. Furthermore, when a mixture of inks is used to form a color image (for example, red is a mixture of magenta and yellow inks, green is a mixture of cyan and yellow inks, and blue is a mixture of cyan and magenta inks). This problem is particularly noticeable.

On the other hand, in a recording method that ejects ink downward,
There is a problem in which liquid IA adheres as shown in FIG. 31. Here, the holder 3029 of the inkjet recording head IJP, the ink ejection part Ha of this head rJP,
A top plate 3033 for forming a liquid path, a discharge portion 3034 generally called an orifice, and a substrate 3031 equipped with a discharge energy generating element corresponding to this liquid path. A recording head having these silicon substrates 3030 is shown.

Note that this ink ejection portion Ha is usually subjected to a water repellent treatment.

This liquid IA is thought to be generated for the following reasons.

Firstly, the moisture in the recorded ink adheres after evaporation and forms condensation, secondly, the ink mist generated during recording adheres, and thirdly, due to contact with the cap of the recording head. This is due to residual ink or ink remaining after cleaning.

Although this liquid IA has the advantage that the fixing effect is promoted by heat, especially when an electrothermal transducer with excellent recording responsiveness is applied as the ejection energy generating element, the above-mentioned recording head configuration It has been found that the above problems tend to occur frequently. Furthermore, when the printing duty is high, such as when forming a color graphic image, the above-mentioned problem often occurs in welding.

The liquid IA generated due to these causes is
34, the ejection direction of the ejected ink is changed and the quality of the recorded image is degraded.

That is, in a recording method in which ink is ejected in a substantially horizontal direction, such a problem does not occur because the liquid IA flows away from the ink ejection part Ha due to the action of gravity.
On the other hand, in a recording method in which ink is ejected substantially vertically downward, the problem shown in FIG. 30 does not occur, but the problem described with reference to FIG. 31 occurs.

In order to effectively solve this problem, as in this embodiment, it is necessary to tilt the recording area with respect to the horizontal plane, and to make the ink ejection part Ha almost parallel to the recording area. Preferably, the recording head is tilted.

That is, by adopting the configuration and arrangement of the recording area as shown in FIG. 32, the problem as shown in FIG. 30 caused by the recording area being oriented in the vertical direction can be solved. Further, by taking the posture of the recording head as shown in FIG. 32, the liquid IA can be quickly flowed away from the area of the ink ejection portion Ha as shown in FIG. 33.

Therefore, in this embodiment, the above-mentioned inclination angle (θ) is appropriately determined. To this end, the present inventors used plain paper as a recording medium, and variously changed the inclination angle θ, that is, the angle that the recording area or ink ejection part makes with the horizontal plane (hereinafter also referred to as printing angle), as shown in FIG. 30. Evaluations were made regarding density unevenness due to ink flow as shown in FIG. 31 and wetting of the surface of the ink discharge portion 8 as shown in FIG.

The results are shown in Table 1.

(Margin below) As is clear from the wooden surface, the printing angle θ is 25° to 4
It was found that the angle is preferably 01, and more preferably 25'' to 35°.

By locating the ejection port surface at such an angle, the liquid IA caused by the suction recovery operation and others flows down to the lower part of the ejection port surface as shown in FIG. 33, and does not remain in the ejection port formation area Ha. This can be completely removed by further abutting an ink absorber provided at the bottom of the cap portion 420 in FIG. 13 or elsewhere, or provided separately.

Also, although it depends on the fixability on the recording medium, the angle (40
(more preferably 35 degrees or less) may be maintained not only in the recording area but also on the downstream side in the conveyance direction. Alternatively, a configuration may be adopted in which the conveying path is bent at an angle less than the above angle until the ink flow becomes a problem. If there is almost no conveyance distance between them, the paper discharge tray 2009 itself may be arranged so that the angle is equal to or less than the above angle.

Next, in view of the fixing properties of such a recording medium, it is also preferable to be able to change the printing angle θ.

FIG. 34 shows an example of its configuration, where NOV is a drive unit that supports the platen P and recording head H in a movable manner (printing angle can be changed), CON is a controller for making the displacement, and SEN is a fixing unit. This is a photosensor for detecting recording media with poor quality, such as OHP films.

As shown in the figure, in this example, the recording area has two types of angles θ1... with respect to the horizontal plane O depending on the type of recording medium. θ2(
The platen P can be set at a position PA shown by a solid line and a position PB shown by a broken line so that θ1>θ2). Additionally, in conjunction with this, the print head H (or the carriage that supports it) can be set at positions HA and HB so that the ink ejection portion is parallel or nearly parallel to the print area. In other words, when sensor SEN detects an OHP film, etc. with poor fixing properties (low absorbency), the angle θ1 selected for plain paper, etc. with good fixing properties (high absorbency) is , the angle θ smaller than this
The printing angle can be changed to 2. Additionally, integrally or independently, the angle θH formed by the ink ejection portion with respect to the horizontal plane is also made small in the case of an OHP film or the like.

Note that the angle θH that the ink ejection section makes with respect to the horizontal plane (that is, the angle that defines the distance (head gap) between the recording medium and the ink ejection section) changes depending on the thickness of the recording medium, as described above. It may be determined by the member used. The drive unit under the control of the controller CON,
It may be determined by MOV. In addition, from the viewpoint that it is sufficient that the ink discharge part and the recording area are almost parallel, and from the viewpoint of preventing ink flow on the recording medium and liquid adhesion on the ink discharge part, the points shown in Table 1 are as follows. Accordingly, the angle (θ1, θ2) that the platen makes with respect to the horizontal plane and the angle (θH) that the ink ejection unit makes with the horizontal plane may be independently controlled by the drive unit MOV.

Moreover, instead of changing the angle in this way, the recording density within a predetermined time may be changed (those with poor fixing properties are made smaller than those with good fixing properties).

Incidentally, as shown in FIG. 35, the above is similarly effective in obtaining an appropriate printing angle θ even when a so-called full multi (full line) type recording head is used.

In the same figure, 40388, 4038C, 4038
M and 4038Y are so-called full multi-type (full line type) black, cyan, magenta, and yellow recording heads in which ejection ports are provided over a range corresponding to the paper width of the recording medium S, respectively.

Then, as described above, the conveyance roller 4036
The ejection direction of the recording head is set at 25° to 35° with respect to the vertical plane so that the ink is ejected perpendicularly or almost perpendicularly to the recording surface of the recording medium S that is being conveyed at an angle of 25° to 35° from the horizontal plane. By oriented downward, the surface of the ejection port is less likely to get wet, and ink flow on the recording medium can be prevented. Therefore, a good image can be formed with less bleeding at the boundary between different color inks.

In the figure, 4029 is a recovery unit for improving the discharge condition, and includes a cap and the like.

By the way, when the configurations shown in FIGS. 11A and 11B are adopted, or when the configuration shown in FIG. 34 is adopted, the carriage of the recording head is tilted depending on the thickness or type of the recording medium. This results in displacement. Since the sub-tack 300 is attached to the carriage, its posture also changes.

As described above, in this example, the volume ratio between the air portion and the ink portion in the ink chamber of the sub-tank 300 is appropriately determined. Since the ink chamber is almost a closed system, even if the attitude of the sub-tank 300 changes, the above-mentioned volume ratio does not change in a short period of time, and a good operating condition can be obtained.
If air is mixed into the supply system after that, it will be introduced into the sub-tank 300, so that the ratio of the air portion may gradually become too large. Furthermore, due to variations in the amount of air mixed in due to differences in the length of the ink supply system, the volume ratio may vary among the sub-tanks, and the above-mentioned water head difference may also vary. In order to eliminate this variation (and achieve a uniform and good volume ratio in each head), the pump 44 described above is
By driving 0, suction is performed from the internal space of the sub-tank 300 via the suction pipe 444, but if this is performed at an arbitrary timing, there is a risk that an appropriate volume ratio may not be obtained. This is because a change in the attitude of the sub-tank 300 changes the height of the suction port that defines the liquid level within the sub-tank.

Therefore, in this example, the position of the suction port is determined so that an appropriate volume ratio can be obtained if suction is performed when the sub-tank 300 is in a predetermined posture, and suction is performed only when the sub-tank 300 is in the predetermined posture. do it like this.

The predetermined posture can be, for example, when the recording medium is not being conveyed and is in a basic posture in which carriage displacement (rotation around the shaft 213) cannot occur. Specifically, by using the timing between the end of recording on one or more recording media and the time when the next recording medium is conveyed, there will be no drop in recording throughput and a good quality can be achieved at all times. The volume ratio can be secured.

Note that in this example, a single pump is used for the recovery system and the suction system from the sub-tank for one color, and suction is performed at the same time, but from the viewpoint of maintaining the volume ratio,
The recovery process may also be performed at the above timing. Alternatively, by installing a valve in the middle of the suction path from the sub-tank and opening and closing it appropriately, it is possible to perform the recovery process without suction from the sub-tank, that is, without changing the volume ratio. Recovery processing can be performed even during recording processing on a single recording medium.Furthermore, the pumps of both systems may be separate units and driven independently of each other.

It goes without saying that appropriate modifications can be made without departing from the spirit of the present invention.

For example, on the upper side, a recording head, an ink tank, an ink supply system, an ink discharge system, an ink communication member, etc. are provided to accommodate ink of different colors, but it is not necessarily limited to ink of different colors; Each section may be provided corresponding to ink having widely different color tones, such as ink.

(Others) The present invention brings about excellent effects particularly in a bubble jet type recording head and recording apparatus among inkjet recording types.

This is because such a system can achieve higher recording density and higher definition.

For example, see its typical configurations and principles.

U.S. Patent No. 4723129, U.S. Patent No. 474079
Preferably, the method is carried out using the basic principle disclosed in the specification of No. 6. This method can be applied to both so-called on-demand type and continuous type, but in particular,
In the case of the on-demand type, the electrothermal transducer placed in correspondence with the sheet holding the liquid (ink) or the liquid path has a rapid temperature rise that corresponds to the recorded information and exceeds nucleate boiling. The electrothermal transducer generates thermal energy by applying at least one drive signal that provides a drive signal that causes film boiling to occur on the thermally active surface of the recording head, resulting in one-to-one correspondence to this drive signal. This is effective because it can form air bubbles within the liquid (ink). The growth and contraction of the bubble causes liquid (ink) to be ejected through the ejection opening to form at least one droplet. It is more preferable to use this drive signal in a pulse form, since the growth and contraction of bubbles can be carried out immediately and appropriately, making it possible to eject liquid (ink) with particularly excellent responsiveness. This pulse-shaped drive signal is described in U.S. Pat. Nos. 4,463,359 and 434.
5262 is suitable. Furthermore, if the conditions described in US Pat. No. 4,313,124 concerning the invention regarding the temperature increase rate of the heat acting surface are adopted, even more excellent recording can be performed.

The configuration of the recording head includes a combination configuration of an ejection port and a liquid path 1 electrothermal converter (straight liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned specifications, as well as a heat acting section. The present invention also includes configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose configurations in which the wafer is placed in a bending region. In addition, Japanese Patent Application Laid-Open No. 1989-5 discloses a configuration in which a common slit is used as a discharge part of a plurality of electrothermal converters.
No. 9-123670 and Japanese Patent Application Laid-Open No. 59/1989 which discloses a configuration in which a discharge portion is made to correspond to an opening that absorbs pressure waves of thermal energy.
The effects of the present invention are also effective even if the structure is based on the publication No.-138461. That is, regardless of the form of the recording head, according to the present invention, recording can be performed reliably and efficiently.

Furthermore, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium that can be recorded by a recording apparatus.

Such a recording head may have either a configuration in which the length is satisfied by a combination of a plurality of recording heads, or a configuration as a single recording head formed integrally.

In addition, even with the serial type shown above, the recording head is fixed to the device body, or by being attached to the device body, electrical connection to the device body and ink supply from the device body are possible. The present invention is also effective when using a replaceable chip type recording head or a cartridge type recording head in which an ink tank is integrally provided in the recording head itself.

Further, it is preferable to add recovery means for the recording head, preliminary auxiliary means, etc., which are provided as a configuration of the recording apparatus, to the present invention, because the effects of the present invention can be further stabilized. Specifically, these include capping means for the recording head, cleaning means, pressure or suction means, preheating means using an electrothermal transducer or another heating element, or a combination thereof; It is also effective to perform a preliminary ejection mode in which ejection is performed separately from recording in order to perform stable printing.

In addition, regarding the type and number of recording heads installed, for example, in addition to one type that corresponds to single-color ink, there is also a plurality of recording heads that correspond to multiple inks with different recording colors and densities. It may be something that can be done. That is, for example, the recording mode of the recording device is not only a recording mode of only the mainstream color such as black, but also a recording mode of multiple colors of different colors, although the recording head may be configured integrally or by a combination of multiple heads. The present invention is also extremely effective for devices equipped with at least one of full colors, or mixed colors.

In addition, in addition to being used as an image output terminal for information processing equipment such as a computer, the inkjet recording apparatus of the present invention may also take the form of a copying machine combined with a league, etc., or a facsimile machine having a transmission/reception function. It may also be something.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, for example, a sub-ink tank chamber provided corresponding to a plurality of ink colors, and a plurality of ink supply sources consisting of supply tubes, ink tanks, etc. By making the water head difference between the sub-ink tank chambers the same, the volumes of the ink section and the air section can be made the same between the sub-ink tank chambers.
This makes it possible to provide sub-ink tanks with a simple configuration in which each sub-ink tank chamber has the same shape, and it is also possible to effectively buffer pressure fluctuations occurring in the ink supply source or the like in the air section.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view of an inkjet recording device according to an embodiment of the present invention, and FIGS. Figure 3 is a cross-sectional view showing the recording head section mounted on the carriage; Figures 4 (A) to (C) are the side sectional view and top view shown with the device cover removed; FIGS. 5A to 5C are explanatory diagrams for explaining details of the head cover according to this example. FIG. 6 is a diagram showing recording head positioning using a head cover according to another embodiment. 7(A) and (B) are perspective views showing an example of the configuration of the sub-tank shown in FIG. 2. FIG. 7(C) is an ink supply system driven by a carriage. Figure 8 is an exploded perspective view of the sub-tank; Figure 9 is a cross-sectional view of another embodiment of the sub-tank; Figure 10 is the connection used in the ink supply system. Top view showing a configuration example of a pipe and a tube unit, FIG. 11(A)
i3 and (B) are side sectional views for explaining the operation of the paper feeding mechanism according to this example when transporting thin paper and thick paper, respectively; FIG. 12 (A)! 3 and (B) are side sectional views for explaining the operation of the paper feeding mechanism according to this example when transporting thin paper and thick paper, respectively, and FIG. 13 shows a schematic configuration of the recovery unit according to this example. 14(A) and 14(B) are a detailed side sectional view of the recovery unit and a front view of the pump holding part thereof, and FIG. 15 is a schematic side sectional view showing the opening/closing mechanism of the atmospheric communication hole in the cap part. FIG. 16 is a side sectional view of the recovery unit centered on the opening/closing mechanism, etc., and FIGS. 17(A) to (C) are views of the cap advancement/retraction mechanism, etc. according to this example. 18(A) to 18(C) are explanatory diagrams for explaining the configuration and operation of the pump used in this example. FIG. 19 is a schematic diagram showing an example of the pump drive system. FIG. 21 is an explanatory diagram for explaining the timing of the operation of each part of the recovery unit according to this example. FIG. 21 is a plan view of the ink tank storage section for explaining the ink tank arrangement according to this example, and FIGS. 23(A) and 23(B) are explanatory diagrams for explaining ink pressure fluctuations due to carriage operation, and FIG. 25A and 25B are explanatory diagrams showing the relationship between the remaining amount of ink and the negative pressure in the ink flow path, and FIGS. 25A and 25B are conventional ink pressure detection diagrams shown for comparison with the ink pressure detection device of this example. 26(A) and 26(B) are a top view for explaining an example of the configuration of the ink supply pipe connection part and its operation according to the present example, and FIG. 27 is a top view of the device. 28 (A) and (B) are a perspective view and a side sectional view showing an example of a configuration for holding one joint forming the connection portion on the copper plate wall surface, and FIG. 29 (A) and (B) are side sectional views. Figure 30 is an explanatory diagram for explaining the occurrence of problems when the printing angle is set perpendicular to the horizontal plane; Figure 31 is an explanatory diagram for explaining the occurrence of problems when the printing angle is set horizontally; Fig. 32 is an explanatory diagram for explaining the printing angle according to this example, Fig. 33 is an explanatory diagram for explaining one of its effects, and Fig. 34 is an explanatory diagram for explaining the printing angle according to the type of recording medium. FIG. 35 is an explanatory diagram showing an example of the configuration. FIG. 35 is an explanatory diagram for explaining the printing angle when a full multi-type recording head is used. 10...Recording head chip, 11... Front plate, 13 ... Supply pipe, 15 ... Guide groove, 201 ... Carriage body, 203 ... Carriage cover 205 ... Head cover 211 ... Position lever 213 ... Guide shaft, 215 ... Guide, 217... Reference plane, 221.223... Leaf spring, 300... Sub tank, 311... Tube, 3218K (C, M, Y), 3238K (C
, M, Y), 3258K (C, M, Y)...
・Connection pipe, 331... Tank member, 3318K (C, M, Y)... Storage chamber, 333...
Middle plate, 335... Connection plate, 337C(M), 339C(M)... Connection groove, 3
41C(M), 343C(M)...Connecting hole, 40
0...Recovery unit, 401...Unit housing, 403...Motor,...Worm,...Worm wheel. ...cap part, ...pump, ...cam, ...lever ...access lever ...cap holder, ...atmosphere communication hole, ...paper feed tray, ...spring, ...pickup roller, ...separation plate, ...paper feed roller, ...pinch roller, ...platen, ...paper ejection roller, ...pinch roller holder, ...carriage rail, ... Spring, 7018K (C, M, Y) ... Ink tank, 7
038K (C, M, Y)...Ink supply pipe, 7078
K (C, M, Y)... Waste ink pipe, 801... Channel member, 803... Ink channel, 807... Diaphragm, 809... Holding member, 819... Latching Piece, 823...Spring, 825...Spring stop ring, 901.921...Joint, 905...Valve body, 925...Communication pipe section. Engraving of the drawings (no changes in content) Figure 4 <C) Figure 5 (A) Figure 7 Mother-in-law and 4P1. Figure 9 Figure 12 (A) Figure 15 Figure 16 Figure 17 Figure 19 (A) 11! Figure 26 (A) 301 Sa-b Figure 28 Figure 29 Figure 30 Figure IJP Figure 31 Figure 32 A Figure 33 Figure 35 Procedural Amendment (75' stamped February 15, 1991)

Claims (1)

[Scope of Claims] 1) In an inkjet recording method in which recording is performed using ink in a recording area where a recording medium and an inkjet recording head face each other with a gap therebetween, with respect to a horizontal plane in the conveying direction of the recording medium in the recording area. An inkjet recording method characterized in that the angle θ formed is in a range of 25 degrees or more and 40 degrees or less. 2) The inkjet recording method according to claim 1, wherein the angle θ is in a range of 25 degrees or more and 35 degrees or less. 3) The inkjet recording head applied to the inkjet recording method includes an inkjet section that faces the recording medium and includes a plurality of inkjet portions, and generates thermal energy for ejecting ink from the inkjet portions. 3. The inkjet recording method according to claim 1, further comprising: an electrothermal converter. 4) In an inkjet recording apparatus comprising a conveyance means for conveying a recording medium to a recording area where the recording medium and an ink ejection part of an inkjet recording head face each other with a gap therebetween, the conveyance means conveys the recording medium in the recording area. An inkjet recording apparatus characterized in that an inkjet recording apparatus performs recording with an angle θ formed with respect to a horizontal plane in a range of 25 degrees or more and 40 degrees or less. 5) The inkjet recording apparatus according to claim 4, wherein the angle θ is in a range of 25 degrees or more and 35 degrees or less. 6) The inkjet recording head applied to the inkjet recording apparatus includes an inkjet section that faces the recording medium and includes a plurality of inkjet portions, and generates thermal energy for ejecting ink from the inkjet portions. 6. The inkjet recording apparatus according to claim 4, further comprising: an electrothermal transducer. 7) An inkjet recording head including an ink ejection section facing a recording medium, a recording area where the recording medium and the ink ejection section of the inkjet recording head face each other with a gap therebetween, and transporting the recording medium to the recording area. a means of transport;
In the inkjet recording apparatus, the conveyance means makes an angle θ in the recording area with respect to a horizontal plane in the conveyance direction of the recording medium in a range of 25 degrees or more and 40 degrees or less, and the inkjet recording head has the ink ejection section An inkjet recording apparatus characterized by being mounted on a carriage in a state substantially parallel to the surface of a recording medium and ejecting ink diagonally downward. 8) The inkjet recording head includes 64 or more ink ejection portions in the ink ejection portion facing the recording medium, and the angle θ is in a range of 25 degrees or more and 35 degrees or less. The inkjet recording device described in . 9) The inkjet recording apparatus according to claim 7 or 8, wherein the inkjet recording head includes an electrothermal transducer that generates thermal energy for ejecting ink from the ink ejection portion. 10) An inkjet recording head including an ink ejection section facing a recording medium, a recording area where the recording medium and the ink ejection section of the inkjet recording head face each other with a gap therebetween, and conveying the recording medium to the recording area. An inkjet recording apparatus comprising: a conveying means, the conveying means being capable of conveying different types of recording media to the recording area, and transporting the recording medium relative to a horizontal plane in the recording medium conveyance direction in the recording area. The angle θ is 2
The inkjet recording head has an angle in the range of 5 degrees or more and 40 degrees or less, and the inkjet recording head is capable of setting the ink ejection section at different angles with respect to the different recording media, and the angle formed by the ink ejection section with respect to the horizontal plane. An inkjet recording apparatus characterized in that θ_H is in a range of 25 degrees or more and 40 degrees or less, and ink is ejected diagonally downward. 11) The different types of recording media include a first recording medium that has a relatively low ink absorbency and a second recording medium that has a higher ink absorbency than the first recording medium, and the ink ejection 11. The inkjet recording apparatus according to claim 10, wherein the angle θ_H formed with respect to the horizontal plane of the portion is smaller with respect to the first recording medium than with respect to the second recording medium. 12) The different types of recording media include a first recording medium that has a relatively low ink absorbency and a second recording medium that has a higher ink absorbency than the first recording medium, and the ink ejection The angle θ_H formed with respect to the horizontal plane of the part is a larger angle with respect to the first recording medium than with respect to the second recording medium, and the recording density within a predetermined time of recording on the first recording medium is 11. The inkjet recording apparatus according to claim 10, further comprising a recording means that makes the recording density smaller than the recording density recorded on the recording medium within a predetermined time. 13) The inkjet recording head includes 64 or more ink ejection portions in the ink ejection portion facing the recording medium, and the angle θ and the angle θ_H are in a range of 25 degrees or more and 35 degrees or less. Claim 10
13. The inkjet recording device according to any one of items 1 to 12. 14) The first recording medium is a recording medium including a transparent resin portion, and the inkjet recording head includes an electrothermal transducer that generates thermal energy for ejecting ink from the ink ejection portion. The inkjet recording apparatus according to any one of claims 11 to 13, further comprising an inkjet recording apparatus.