JPH03136858A - liquid jet recording device - Google Patents

Abstract

PURPOSE:To make a unit compact and high speed recording stable by providing a start position between a home position for a main operation carriage and a recording area and an engagement position between former two and a device to give elastic power in the forward-moving direction and backward-moving direction of the carriage. CONSTITUTION:A home position A and a start position B are based on a carriage 2 positioning part 2a. If the carriage 2 finishes is printing, the positioning part 2a of the carriage 2 comes in contact with the positioning part 4a of a holder 4 at point C. In addition, if the carriage 2 moves in (a) direction, the holder 4 moves together, reaching a start position B. After this holder moves backward, it moves in (d) direction. In this case, a spring 8 acts concurrently as a damper when the carriage 2 stops at a start position. If the carriage 2 moves in (d) direction for printing, the holder 4 also moves together by the force of the spring 8. Then the positioning pin 4 of the holder 4 comes in contact with an elastic member 9 and the holder 4 stops, becoming separated from the carriage 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid jet recording apparatus equipped with a capping device for preventing clogging of droplet ejection ports of an ink jet head. [Prior Art] Conventionally, a capping device for preventing clogging of the droplet ejection ports of an inkjet head first moves a main scanning carriage carrying the inkjet head to a predetermined position, and then caps the nozzles of the inkjet head. A cap, which is generally made of an elastic material and covers the inkjet head, is pressed against the inkjet head using the power of a plunger or motor to seal the nozzle part. However, in such a configuration, in order to accurately determine the relative position of the nozzle part and the cap, the movement accuracy of the main scanning carriage is required to be high, and the accuracy of each component is also required to be high, and the device configuration is also complicated. The cost was high. Using the movement of the main scanning carriage 2 on which the inkjet head is mounted, the cap 3 is attached to the inkjet head 1.
A capping device has been devised that presses against the Third
Figures (a), (b), and (c) show this conventional configuration. Figure 3(a) shows the extreme end reversal position during normal recording, Figure 3(b) shows the contact position between the carriage and the cap holder, and Figure 3(C) shows the cap position. There is. In this configuration, when the main scanning carriage 2 moves to the position shown in FIG. , moves along the cam surface of the guide member 6, and presses the cap 3 against the inkjet head l at a position further away from the recording area as shown in FIG. However, because the capping position and the recovery position of the recording head are kept at the same position, that is, the same position as shown in FIG. [Problems] As mentioned above,
In the above conventional example, during printing, the inkjet head
In order to keep the condition of each ejection port constant, when ejecting droplets from all ejection ports (called preliminary ejection or idle ejection) into the cap 3, the scanning amount of the carriage 2 is set to the normal printing. This has the disadvantage that the scanning distance is longer than that required for printing, and the printing speed is reduced. In addition, from another point of view, if the contact point of the positioning part shifts to the home position side to perform capping operation at the home position, the home position position also shifts to the opposite side from the printing side, so the liquid jet There was a drawback that the main body of the recording device became large. In addition, from another perspective, there are cases where the recording head mounted on the carriage has multiple heads to perform dark and light ink or color recording, which increases the weight at the same time. When a recording head is installed, the weight increases compared to the conventional permanent type. As a result, the inertia of the carriage on which the print head is mounted has increased (this has tended to cause ink scattering when the carriage is reversed, and poor position accuracy due to insufficient braking force. Since the moving speed of the carriage increases in order to achieve high-speed recording, the above problem must be recognized as a more serious problem. [Summary of the Invention] A start position located between the home position of the main scanning carriage and a recording area facing the recording medium, and a cap holder and the main scanning carriage located between the start position and the recording area. means for applying an elastic force to the carriage in a direction opposite to the moving direction with respect to the engagement position with the main scanning carriage engagement portion and the movement of the carriage from the engagement position to the start position. Since this is a liquid jet recording device that is characterized by having
It is possible to achieve miniaturization of the device and stabilization of high-speed recording. A second aspect of the present invention provides a start position located between the home position of the main scanning carriage and a recording area facing the recording medium and performing recording, and a start position located between the start position and the recording area. , the engagement position between the main scanning carriage and the main scanning carriage engagement portion of the cap holder, and the engagement position, the start position, or the movement of the carriage from the engagement position between these to the start position. Since the liquid jet recording apparatus is characterized in that it has a means for preliminarily ejecting droplets into the cap while the inkjet head and the cap are separated and facing each other during movement, the inkjet head and the cap are separated from each other and face each other. The time required for recording can be shortened and even higher speed recording can be achieved. A third aspect of the present invention provides a start position, which is a reversal position during recording, located between the home position of the main scanning carriage and a recording area where recording is performed facing the recording medium; an engagement position between the main scanning carriage and the main scanning carriage engagement portion of the cap holder, which is located between the recording area, and in the starting position, the inkjet head and the cap are separated from each other and face each other. Since the liquid jet recording apparatus is characterized by this, the above-mentioned problem at the time of carriage reversal, particularly at high-speed reversal, can be solved and normal recording can be stabilized. [Example] The configuration of this example will be described using FIG. 1 and FIGS. 2(a) to (C). In this embodiment, the requirements of the invention described above are described as a most suitable embodiment in which the requirements of the invention are partially adopted. First, in FIG. 1, a main scanning carriage 2 having an inkjet head 1 is supported by a main scanning rail 7 and is movable in directions of arrows a and d for printing. Further, a holder 4 is disposed on the bottom plate 5 side of the main body, and is made of an elastic material and has a cap 3 that covers the tip of the inkjet head 1 to prevent clogging of the ejection port of the inkjet head 1. The holder is slidably placed on a guide 6 fixed to the bottom plate 5 by a positioning pin 4b of the holder. Further, the holder 4 is always pressed in the direction of arrow d by a spring 8. Further, A is a non-printing position where capping to prevent clogging of the inkjet head 1 and operations to recover a clogged ejection port are performed, such as suction recovery, pressure recovery, and circulation recovery of ink in the head. B is a normal standby position called a home position of the main scanning carriage 2, and a position called a start position where the main scanning carriage 2 starts operation for printing. In this case, the home position A and the start position B are based on the positioning portion 2a of the carriage 2. Next, the operation of the above configuration will be explained using FIGS. 2(a) to 2(C). The spring 8 in FIG. 1 is arranged diagonally, but in FIG. 2 it is arranged parallel to the desired pressing direction. After scanning and printing, the carriage 2 moves toward the start position B (in the direction of arrow a), and reaches the position of the carriage 2 at point C (standby position of the carriage 2) in FIG. Positioning part 2
a comes into contact with the positioning portion 4a of the holder 4. When the carriage 2 further moves in the a direction, the holder 4 also moves in the a direction together with the carriage 2 and reaches the start position B (Fig. 2 (b)), and the carriage 2 is reversed at this position to start the next printing. Therefore, change the direction of movement in the direction of arrow d. At this time, the spring 8 provided to press the holder 4 toward the printing side for positioning the carriage 2 and the holder 4 acts as a damper to suppress vibrations when the carriage 2 stops at the start position (when reversing). It also serves as a job. At this start position, the inkjet head and the cap are separated from each other and face each other, so the cap is effective in collecting the scattered ink when the carriage is reversed, especially when the ink is scattered due to the inertial force during high-speed reversal. achieve. In this example,
Furthermore, since the cap is close to the recording head, its effectiveness is further improved. The carriage 2 moves from the start position B in the d direction for the next printing. At this time, the holder 4 also moves in the d direction together with the carriage 2 by the force of the spring 8. Then, the positioning pin 4d of the holder 4 comes into contact with the elastic member 9 provided on a part of the stopper of the guide member 6, and the holder 4 stops and leaves the carriage 2. At this time, the elastic member 9
This function prevents the noise that would otherwise occur due to contact between the positioning pin 4d and a portion of the stopper of the guide member 6. The elastic member 9 in this case may be made of rubber or may be a compression coil spring. Furthermore, when ejecting droplets from all ejection ports (dry ejection) in order to keep the state of each ejection port constant during printing, the method shown in Fig. 2 (
If idle ejection is performed between position C and start position B in b), droplets resulting from idle ejection from the inkjet head 1 can be ejected into the cap 3. In this case, if the distance from the positioning part 2a of the carriage 2 to the center 1a of the ejection opening of the inkjet head 1 is the same, then the distance C from the positioning part 4a of the holder 4 to the center 3a of the cap 3 is the same for each head and cap. With this setting, when the positioning portion 2a of the carriage 2 and the positioning portion 4a of the holder 4 come into contact, the inkjet head 1 and the cap 3 can be positioned in the main scanning direction. In addition, during non-printing, as shown in FIG. 2(c), the carriage 2 moves beyond the start position B and further moves in the direction a, and as described in the conventional example, the positioning bin 4b disposed on the holder 4 As the holder 4 moves along the slope of the guide member 6, the holder 4 also moves toward the carriage 2 while moving in the direction a. Finally, at the home position A, the cap 3 comes into contact with the inkjet head 1, and the capping operation is completed. In the home position, if the ejection port of the inkjet head 1 becomes clogged, operations such as creating a negative pressure inside the cap 3 and drawing suction from the ejection port to restore the original state from the clogging state are possible. This is performed using a suction pump, tube, etc. (not shown). Figure 4 shows an ink tank 1 instead of the permanent type recording head for four colors of normal Y, M, C, and B.
Although the recording head is of a disposable type and is integrated with the 00, the other configurations described above are the same as those described above. FIG. 4 is a side view of this embodiment, FIGS. 5(a) and 5(b) are explanatory diagrams of the structure of the carriage of this recording head, FIG. 6 is a top view when the carriage is in the recording area, and FIG. 7 is FIG. 6 is a top view showing a state in which each head and each cap are facing each other and are separated from each other at an engagement starting point where the carriage and the cap holder engage with each other. In FIG. 4, reference numeral 101 denotes a control means that applies a recording signal R to each recording head 1 when the carriage is in the recording area, and as needed from the engagement position C to the start position B. While the carriage is moving to or at these positions C and B, a preliminary ejection signal PRE for preliminary ejection of droplets into the cap is applied to the recording head while the inkjet head and the cap are separated and facing each other. . Note that 10 is a fixing portion of the spring 8, and a spring hook fixed to the device is provided on a member 11. P is a guide that guides the recording sheet S, which is a recording medium, in the recording area. Fifth
Although the figure shows a configuration in which the recording head is positioned by applying pressure to the opening of the carriage laterally using a plate spring 203 and positioning is performed at the bottom of the carriage, the present invention is not limited to this. In this embodiment, since the ink tanks are relatively large, two pairs of symmetrical ink tanks are used, and the heads are located close to each other so that the cap structure can be miniaturized. Therefore, overall,
The above-mentioned metal engraving relationship is achieved by utilizing the space of the carriage, which is becoming larger, and since the above-mentioned characteristics of the present invention are provided, the overall size of the carriage is prevented from increasing. As can be understood from the above embodiment, the main scanning carriage having the inkjet head and the positioning part of the holder having the cap covering the tip of the inkjet head come into contact with each other as the main scanning carriage moves toward the home position, and the inkjet head and In a capping device that positions the cap in the main scanning direction, by having a configuration in which the main scanning carriage and the positioning part of the holder come into contact on the print side from the start position of the main scanning carriage, the positioning of the cap in the main scanning direction can be adjusted. In addition to keeping the amount of movement small and reducing the size of the main body, the positioning accuracy of the carriage and head at the scan start part (start position) is achieved, making it easy to empty the discharge into the cap during print scanning. I made it. Furthermore, when a part of the stopper of the holder provided on the guide member that guides the holder to the capping position and a positioning part that slides on the guide part of the guide member provided on the holder side come into contact when the holder is in the standby position. By placing an elastic member on the guide side or holder side that absorbs shock, noise at the time of contact is reduced and problems caused by contact between the carriage and holder during printing are eliminated. Furthermore, as the printing speed of liquid jet recording devices increases, the moving speed of the carriage tends to increase. In particular, if the speed during backing up (when one printing is completed and then turning over to the home position and returning) is increased, the vibration from backing up will remain when turning over at the start position, making printing stable at startup. In order to achieve this, it has become necessary to take measures such as providing a damper member, increasing the run-up distance before printing, or extending the stopping time of the carriage. In order to position the holder and the carriage, the present invention takes advantage of a configuration in which the positioning portions of the carriage and holder are in contact with each other on the printing side of the start position to solve this problem, and presses the holder on the side opposite to the home position in order to position the holder and the carriage. By using the elastic body provided for this purpose as a damper member when the carriage stops at the home position side, the number of parts and costs are reduced. Additionally, the run-up distance for printing can be shortened, and the carriage stop time can be shortened. The present invention provides excellent effects, particularly in bubble jet recording heads and recording apparatuses among ink jet recording systems, since it can further improve the recording responsiveness of the bubble jet recording head and recording apparatus. As for typical configurations and principles thereof, it is preferable to use the basic principles disclosed in, for example, US Pat. No. 4,723,129 and US Pat. No. 4,740,796. This method can be applied to both the so-called on-demand type and continuous type, but especially in the case of the on-demand type, it is necessary to arrange the liquid (ink) in accordance with the sheet and liquid path that hold it. As an electrothermal converter,
By applying at least one drive signal corresponding to recorded information and providing a rapid temperature rise above nucleate boiling, the electrothermal transducer generates thermal energy to cause film boiling on the thermally active surface of the recording head. As a result, bubbles in the liquid (ink) can be formed in one-to-one correspondence with this drive signal, which is effective. The growth and contraction of this bubble causes the liquid (ink) to be ejected through the ejection opening to form a small (at least one) drop.If this drive signal is in the form of a pulse, the growth and contraction of the bubble will occur immediately and appropriately. This is more preferable since liquid (ink) ejection with particularly excellent responsiveness can be achieved.This pulse-shaped drive signal is described in U.S. Pat. Nos. 4,463,359 and 4,345,262. The above-mentioned U.S. Pat.
If the conditions described in specification No. 3124 are adopted,
Even better recording can be performed. The configuration of the recording head includes, in addition to the combined configuration of ejection ports, liquid paths, and electrothermal converters (straight liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned specifications, a heat acting section. The configuration is placed in a bending area. U.S. Pat. No. 4,558,333 and U.S. Pat. No. 4,459,960 disclose
A configuration using the specification of No. 0 is also included in the present invention. In addition, Japanese Patent Application Laid-open No. 123670 of 1982 discloses a configuration in which a common slit is used as a discharge part for a plurality of electrothermal converters, and a hole that absorbs pressure waves of thermal energy is disclosed. The present invention is also effective as a configuration based on Japanese Patent Application Laid-Open No. 138461 of 1982, which discloses a configuration compatible with a discharge section. Further, it is preferable to add recovery means, preliminary auxiliary means, etc. for the recording head, which are provided as a configuration of the recording apparatus of the present invention, because the effects of the present invention can be further stabilized. Specifically, these include preheating means for the recording head using a caving means, a cleaning means, a pressurizing or suction means, 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 printing in order to perform stable printing. [Effects of the Invention] As explained above, the main scanning carriage having the inkjet head and the positioning part of the holder having the cap covering the tip of the inkjet head come into contact with each other as the main scanning carriage moves toward the home position side, and the inkjet head In a capping device that positions the cap in the main scanning direction, by having a configuration in which the main scanning carriage and the positioning part of the holder are in contact with each other on the printing side from the start position of the main scanning carriage,
The amount of movement of the main scanning carriage can be kept small (the size of the main body can be kept small), and empty ejection into the cap can be performed accurately with a simple configuration within the printing scan of the main scanning carriage.In other words, This prevents the scanning distance of the main scanning carriage from becoming longer due to idle ejection (
, copy speed does not decrease. In addition, since the same cap can be used to recover from clogging of the inkjet head and to process droplets during idle ejection, the process for waste liquid can be simplified. Additionally, contact between the holder and the carriage during print scanning has previously caused problems. Noise caused by contact between part of the stopper of the holder of the guide member and the guide and positioning part of the holder is reduced by placing an elastic body in part of the stopper on the guide side or the positioning part on the holder side. In addition, by actively utilizing the contact between the carriage and holder during print scanning, the elastic body provided to press the holder to the side opposite to the home position is used to position the holder and carriage. By configuring the printer to also function as a damper when stopped at the home position side, it is possible to achieve effects such as improving print quality during start-up during high-speed printing at low cost.

[Brief explanation of the drawing]

Figure 1 is a side view showing the configuration of an embodiment of the present invention, Figure 2 (
a) (b) (c) are explanatory diagrams for explaining the operation of the embodiment shown in Fig. 1, and Figs. 3 (a), (b), (
c) is an explanatory diagram illustrating the configuration of the conventional example, FIG. 4 is a side view of this embodiment, FIGS. 5(a) and (b) are explanatory diagrams of the carriage configuration of this recording head, and FIG. FIG. 7 is a top view showing a state in which each head and each cap face each other and are separated from each other at the starting point of the amount of engagement in which the carriage and the cap holder engage with each other. . 1 is an inkjet head, 2 is a main scanning carriage, 3
is the cap, 4 is the holder, 5 is the bottom plate, 6 is the guide, 7
is the main scanning rail, and 8 is the spring.

Claims (10)

[Claims] (1) It has a main scanning carriage for mounting an inkjet head, and a cap holder having a cap that covers the tip of the inkjet head at the home position. In a liquid jet recording device in which a scanning carriage contacts a main scanning carriage engagement portion of a cap holder and the cap holder and the main scanning carriage move simultaneously to a home position, the home position of the main scanning carriage and the recording medium a start position located between the recording area facing the recording area; and a start position located between the start position and the recording area;
An engagement position between the main scanning carriage and the main scanning carriage engagement portion of the cap holder, and elasticity in a direction opposite to the movement direction of the carriage from the engagement position to the start position. A liquid jet recording device comprising: means for applying force to the carriage. (2) The liquid jet recording device includes a cap of the cap holder facing the inkjet head from the engagement position, and during movement of the carriage from the engagement position to the start position. 2. The liquid jet recording apparatus according to claim 1, further comprising means for preliminarily ejecting droplets into the cap. (3) The liquid ejection head according to claim 1 or 2, wherein the inkjet head mounted on the carriage is a bubble jet type head equipped with an electrothermal converter that generates thermal energy to cause film boiling. Recording device. (4) The carriage is capable of mounting a plurality of inkjet heads, each of which is a bubble jet type head equipped with an electrothermal converter that generates thermal energy to cause film boiling. The liquid jet recording device according to item 1 or 2. (5) It has a main scanning carriage for mounting an inkjet head, and a cap holder having a cap that covers the tip of the inkjet head at the home position, and the main scanning carriage has a cap holder that covers the tip of the inkjet head at the home position. In a liquid jet recording device in which a scanning carriage contacts a main scanning carriage engagement portion of a cap holder and the cap holder and the main scanning carriage move simultaneously to a home position, the home position of the main scanning carriage and the recording medium a start position located between the recording area facing the recording area; and a start position located between the start position and the recording area;
An engagement position between the main scanning carriage and the main scanning carriage engagement portion of the cap holder, and a position where the inkjet head and the cap are separated from each other and face each other during the engagement position, the start position, or during movement of the carriage between these positions. A liquid jet recording apparatus characterized by comprising means for preliminarily ejecting droplets into the cap during the period of time. (6) The liquid jet recording apparatus according to claim 5, wherein the ink jet head mounted on the carriage is a bubble jet head equipped with an electrothermal converter that generates thermal energy to cause film boiling. (7) The carriage is capable of mounting a plurality of inkjet heads, each of which is a bubble jet type head equipped with an electrothermal converter that generates thermal energy to cause film boiling. Liquid injection recording device. (8) It has a main scanning carriage for mounting an inkjet head, and a cap holder having a cap that covers the tip of the inkjet head at the home position, and the main scanning carriage has a cap holder that covers the tip of the inkjet head at the home position. In a liquid jet recording device in which a scanning carriage contacts a main scanning carriage engagement portion of a cap holder and the cap holder and the main scanning carriage move simultaneously to a home position, the home position of the main scanning carriage and the recording medium a start position, which is a reversal position during recording, located between a recording area opposite to the recording area; and a start position, which is located between the start position and the recording area.
a liquid jet recording device comprising: an engagement position between the main scanning carriage and a main scanning carriage engagement portion of a cap holder; and in the starting position, the inkjet head and the cap face each other and are separated from each other. . (9) The liquid jet recording apparatus according to claim 8, wherein the ink jet head mounted on the carriage is a bubble jet head equipped with an electrothermal converter that generates thermal energy to cause film boiling. (10) The carriage is capable of mounting a plurality of inkjet heads, each of which is a bubble jet type head equipped with an electrothermal converter that generates thermal energy to cause film boiling. Liquid injection recording device.