JPH1178050A - Image forming device - Google Patents

Abstract

(57) [Problem] To provide an image forming apparatus capable of easily specifying a clogged nozzle among a large number of nozzles of a head and performing a cleaning process only on the specified clogged nozzle. An image forming apparatus causes an inkjet head to draw a line by sequentially ejecting ink from one end to the other end of a plurality of nozzles of the plurality of nozzles, and to form a straight line between the straight lines at equal intervals. Control section 1 as a head control means for recording the recorded recording check pattern
And the display device 8 and the keyboard 6 or PD 13 as selection means for selecting the nozzle 111 to be cleaned based on the result of the recording check pattern formed by being controlled by the control unit 1. A cap 136 and the like as cleaning means for performing a cleaning process only on the nozzle 111 are included.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus having a cleaning mechanism for eliminating clogging of nozzles of an ink jet head for discharging ink.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus using an ink-jet head (hereinafter simply referred to as a head), in order to find clogging of nozzles of the head, first, printing is actually performed with all nozzles, and the printing is performed. When it is determined that the image as an output result is unclear or dirty, the cleaning process has been performed on all nozzles.

[0003]

However, when only a few of the many nozzles are clogged, it is determined visually whether or not the nozzles are clogged by looking at the print output result. In some cases, it is difficult to determine whether perfect printing without clogging has been achieved.

In the above cleaning process,
Since the suction or idle discharge is performed for all the nozzles at once, there is a disadvantage that the consumption of ink discharged regardless of printing increases and the time required for the cleaning process also increases.

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides an image forming apparatus capable of easily specifying a clogged nozzle among a large number of nozzles of a head and performing a cleaning process only on the specified clogged nozzle. It is intended to provide a device.

[0006]

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to an image forming apparatus for forming an image using an ink jet head for discharging ink toward a recording medium, wherein the image forming apparatus is provided with an ink jet head. Among a plurality of nozzles, from one end to the other end, ink is sequentially discharged from each nozzle to draw a straight line, and a head control means for printing a print check pattern with equal intervals between the straight lines, and the head control means Based on the result of the recording check pattern formed by being controlled,
It is characterized by including a selecting means for selecting a nozzle to be cleaned and a cleaning means for performing a cleaning process only on the nozzle selected by the selecting means.

Here, the selection means may include a display means for individually displaying all the nozzles, and a specification means for individually specifying all the nozzles displayed by the display means.
The display means may have a flat or substantially flat display area. The specifying means may be a pointing device for indicating a specific part in the display area of the display means.

[0008] The cleaning means may include capping means for covering all nozzles of the ink jet head, and pump means for setting a space between the capping means and the ink jet head to a negative pressure. The capping means may include a tube for removing waste ink from nozzles of the inkjet head.

[0009] The ink jet head includes an ink discharge port both constituting a nozzle and an ink flow path communicating with the ink discharge port, and heat energy is supplied to the ink flow path as energy sufficient to discharge ink. A thermal energy generator to be applied may be provided. The thermal energy generator may be an electrothermal converter that causes film boiling of the ink. The ink ejection port may be provided at a position facing the thermal energy generator, and the ink ejection port may be provided on an extension of a direction along a surface of the thermal energy generator.

In the present invention, a memory having a memory, Y,
By executing a print check program for the nozzles that eject M, C, and K inks, finding out which nozzle is clogged, and identifying the number of the clogged nozzle, the clogging is performed. Only the nozzles that are in use can be cleaned. As a result, it is possible to reduce the consumption of ink used independently of printing during cleaning.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the image forming apparatus of the present invention.

Reference numeral 1 in FIG. 1 denotes a control section for controlling the entire apparatus, which is provided with a central processing unit (hereinafter, referred to as a CPU) such as a microprocessor and various I / O ports. , And control is performed by inputting a control signal or a data signal from each unit described later. Reference numeral 2 denotes a read-only memory (ROM) for storing a program of the procedure shown in FIG. 2, a system program, a manager program, other application programs, a character font, a dictionary, and the like. Reference numeral 3 denotes an externally added read-only memory (external RO
M) Read / write memory (RAM) for storing application programs, document information, etc. loaded from 4)
It is. Reference numeral 5 denotes a keyboard control device (specifying means; hereinafter, referred to as KBC) for controlling a keyboard 6 for inputting document information, various commands, and the like. Reference numeral 7 denotes a display control device (hereinafter, referred to as CRTC) for controlling a display device (display means; hereinafter, referred to as a CRT) 8 such as a flat panel having a flat or substantially flat display area using a liquid crystal or the like. Reference numeral 9 denotes a peripheral device control device (hereinafter referred to as PKC) which controls a floppy disk drive (hereinafter referred to as FDD) 10 and a hard disk drive (hereinafter referred to as HDD) 11 as external storage devices.
The program of the procedure shown in FIG. 2 may be stored in the FDD 10 or the HDD 11. Reference numeral 12 denotes a printing apparatus (hereinafter, referred to as PRT) that forms an image using a head. The PRT 12 is an element constituting a part of the image forming apparatus of the present invention. Reference numeral 13 denotes a pointing device such as a mouse (specifying means; hereinafter, referred to as PD).
This can be used to selectively instruct the display on the CRT 8. The specifying means and the display means constitute a selecting means for selecting a nozzle to be cleaned.

In the image forming apparatus shown in FIG.
A program exists on the OM 2, the PRT 12, the HDD 11 or the RAM 3.
It is set so that the target processing is performed while sequentially reading out the program through.

Next, an example of the configuration of the PRT 12 will be described with reference to FIGS.

FIG. 2 is a perspective view showing an example of the ink-jet head, FIG. 3 is a cross-sectional view of the head taken along line XX of FIG. 2, and FIG. 4 is the ink-jet head shown in FIGS. FIG. 5 is a perspective view showing an example of a head unit in which the ink jet head and the ink tank are integrated, and FIG. 5 is a perspective view showing a PRT 12 to which the ink jet head or the head unit can be detachably attached.

In FIG. 2, HD is an ink jet head, and 110 is a base on which the head HD is mounted. The head HD according to the present embodiment is schematically composed of a first head 112 having a row of ink ejection ports 111 and a second head 114 having a row of ink ejection ports 113 independent of the first head 112. . Here, the two heads 112 and 114 have substantially the same structure only in a mirror image relationship with each other, and therefore, as a representative of the two heads, only the configuration of the first head 112 will be described. The description of the configuration of the second head 114 is omitted.

In FIGS. 2 and 3, reference numeral 115 denotes a top plate having a flat surface which constitutes a part of the head face surface. The material for forming the top plate 115 is selected by comprehensively judging whether the moldability is good or not, and whether or not the ink is hardly eroded, and is generally selected from polysulfone. Can be Reference numeral 115a
Is a window formed on a part of the plane of the top plate 115, and the ink discharge ports 111 or 113 are exposed through the window 115a. Reference numeral 117 denotes a heater as a heat energy generator for generating heat energy used for discharging ink on a Si substrate, and a heater board formed with an aluminum wiring portion thereof by a film forming technique. The heater board 117 is provided with a shift register and a driving transistor in order to reduce the number of TAB pads. Further, a concave portion serving as an ink flow path 118 and an ink liquid chamber 119 is formed on the top plate 115 between the heater board 117 and the top plate 115 by molding or laser processing.
Here, the ink flow path 118 communicates with, for example, the ink discharge port 111, and the ink discharge port 111 and the ink flow path 118 form a nozzle. The ink liquid chamber 119 communicates with the ink tank TA shown in FIG. Normally, a sealant is used between the top plate 115 and the heater board 117 to prevent ink from leaking. One end of a wiring board 121 is connected to a terminal of the heater board 117 by wire bonding or the like. Also in this connection, a sealant is used to prevent and protect the connection portion from adhering ink. The other end of the wiring board 121 is curved and fixed to the base 110. First head 112 assembled in this manner
Are bundled and held by an elastic member 122 from the outside. The heater as a heat energy generator will be further described later.

The head HD having such a structure forms a head unit integrally with the ink tank TA as shown in FIG. This head unit includes a head H
In the vicinity of the D fixing position, a concave portion 123 with which the claw of the distribution cap CP can be engaged is formed.

Next, an example of the PRT 12 to which such a head unit HU or head cartridge HC can be detachably attached will be described with reference to FIG.

In FIG. 5, reference numeral 130 denotes a carriage on which two head units HU described above can be mounted at the same time. The carriage 130 is supported by scanning rails 132 and 133 extending parallel to each other on the chassis 131 so as to be reciprocally movable in the extending direction. A drive belt 134 for transmitting drive from a drive motor (not shown) and a head unit H
A flexible cable 135 for transmitting an image signal is connected to the head portion of the U. At a home position HP provided on one end side of the scanning rails 132 and 133, a suction or protection cap (capping means) 136 for the purpose of restoring ejection characteristics for each head of the head unit HU mounted on the carriage 130 is provided. Is provided by using a pump (pump means) (not shown) to make the space between the cap 136 and the head part a negative pressure, or by causing the head 136 to perform an idle discharge so as to discharge ink from the head part or the ink communicating therewith. It is possible to positively eliminate clogging of the flow path (nozzle) and the like. Although not shown, a waste ink tube which communicates with the inside of the cap 136 and removes waste ink from the head is attached to the cap 136.

Next, the operation of the image forming apparatus including the PRT 12 will be described with reference to FIG. FIG. 6 is a flowchart showing an operation in the image forming apparatus shown in FIG.

First, in step 20 of FIG.
"Print Check" displayed on CRT 8
When the “print check” is called by selectively instructing (for example, clicking) at 13 or the like, in step 21, either a color cartridge or a monochrome cartridge is mounted on the carriage 130 of the PRT 12. Is determined.
This determination process can be easily performed by making the configuration of the engagement claws and the like used when the cartridge is mounted on the carriage 130 different between, for example, a color cartridge and a monochrome cartridge. The reason why the discrimination process is performed is that the structure of the head cartridge itself is basically different between color and monochrome, and the data signal for controlling ink ejection is different.

Next, based on the cartridge information determined in step 21, data necessary for "print check" is created in step 22, data is stored in a buffer in step 23, and an output buffer is created in step 24. To store data.

Next, in step 25, the data stored in the output buffer is subjected to a printing process using a recording check pattern for each nozzle of the head cartridge. FIGS. 7 and 8 show the results of this printing process. These FIG.
8 and the results shown in FIG. 8 are obtained when a color cartridge having nozzles 1 to 16 dedicated to Y (yellow), M (magenta), C (cyan), and K (black) inks is mounted. The recording check pattern is such that, from one end to the other end of the plurality of nozzles, ink is sequentially ejected for each nozzle to draw a straight line, and the straight lines are equally spaced. According to such a recording check pattern, if ink is normally ejected from each nozzle, a plurality of straight lines appear at equal intervals, while if there is a non-ejection nozzle, the straight line that should have been drawn by the nozzle is It can be easily discriminated by the fact that the line disappears and the straight line looks wide apart only at that point. FIG. 7 shows that none of the nozzles is clogged, and FIG. 8 shows that some of the nozzles are clogged.
As shown in FIG. 8, the third and seventh nozzles of Y,
The sixth nozzle of M, the tenth nozzle of C, and the thirteenth nozzle of K are clogged.

Next, at step 26, "Clogged nozzle selection" is displayed on the CRT 8. FIG. 9 is a schematic diagram showing an example of the display of “Clogged nozzle selection”. During this display, it is possible to select only the number corresponding to the clogged nozzle. This selection may be made by inputting from the keyboard 6, or by clicking using the PD 13 such as a mouse, or using these input means together. With such a selection, the cleaning process can be performed only on the nozzles that are actually clogged, and the nozzles that are not clogged at all and exhibit normal ejection characteristics can be applied. The cleaning process need not be performed, and the amount of ink consumption required for the cleaning process can be reduced and saved.

Next, at step 27, it is determined whether or not a clogged nozzle exists. If there is no clogged nozzle as shown in FIG. 7, the process ends in step 31.
In this case, "end" displayed in FIG. 9 is selected. On the other hand, when there is a clogged nozzle as shown in FIG. 8, in step 28, "execution" displayed in FIG. select. This allows
The cleaning process can be performed only on the nozzle selected in step 29. After the completion of the cleaning process, a printing process for confirmation is performed in step 30. Here, when it is confirmed that the presence of the clogged nozzle has been resolved, the process ends in step 31. When it is confirmed again that the presence of the clogged nozzle has not been resolved, Return to step 26.

FIG. 10 is different from FIG. 9 in that "clogged nozzle selection" is performed for the nozzles of the monochrome cartridge.
It is a schematic diagram which shows the other example of display of. The selection display of “end” and “execution” in FIG. 10 is the same as in FIG. In any of the head cartridges, if necessary, cleaning processing can be performed on all nozzles. For example, if no printing is performed at all in the printing executed in step 25 of FIG. 6, it is necessary to perform a cleaning process on all nozzles.

In the present embodiment, the user's vision may be used to determine the presence or absence of the clogged nozzle in step 27, but in order to be more accurate, FIG. 7 or FIG. Alternatively, a clogged nozzle may be identified from the read image by photoelectrically reading a linear image as shown in FIG.

FIG. 11 shows details of the ejection openings of the head shown in FIG. 2, and is a schematic diagram showing an example of the arrangement of the ejection openings of the head in the color cartridge. By using the head having the configuration shown in FIG.
Or the result of FIG. 8 is obtained.

(Others) It should be noted that the present invention includes a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for performing ink ejection, particularly in an ink jet recording system. An excellent effect is obtained in a recording head and a recording apparatus of a type in which the state of ink is changed by the thermal energy. This is because according to such a method, it is possible to achieve higher density and higher definition of recording.

The typical configuration and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method is a so-called on-demand type,
Although it can be applied to any type of continuous type, in particular, in the case of the on-demand type, it can be applied to a sheet holding liquid (ink) or an electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recorded information and providing a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal transducer, and film boiling occurs on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal on a one-to-one basis.
This is effective because air bubbles inside can be formed. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of a liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further, if the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As the configuration of the recording head, in addition to the combination configuration (straight liquid flow path or right-angle liquid flow path) of the discharge port, liquid path, and electrothermal converter as disclosed in the above-mentioned respective specifications, U.S. Pat. No. 4,558,333 and U.S. Pat. No. 44,558 which disclose a configuration in which a heat acting portion is arranged in a bending region.
A configuration using the specification of Japanese Patent No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Application Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters, and an aperture for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the configuration is based on JP-A-59-138461, which discloses a configuration corresponding to a discharge unit. That is, according to the present invention, recording can be reliably and efficiently performed regardless of the form of the recording head.

Further, 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 on which a recording apparatus can record. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads, or a configuration as one integrally formed recording head.

In addition, even in the case of the serial type as described above, a recording head fixed to the apparatus main body or an electric connection with the apparatus main body or ink from the apparatus main body by being attached to the apparatus main body. The present invention is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is provided integrally with the recording head itself is used.

It is preferable to add a recording head ejection recovery unit, a preliminary auxiliary unit, and the like as the configuration of the recording apparatus of the present invention since the effects of the present invention can be further stabilized. If these are specifically mentioned, the recording head is heated using capping means, cleaning means, pressurizing or suction means, an electrothermal transducer, another heating element or a combination thereof. Pre-heating means for performing the pre-heating and pre-discharging means for performing the discharging other than the recording can be used.

The type and number of recording heads to be mounted are, for example, not only one provided for single color ink, but also a plurality of inks having different recording colors and densities. A plurality may be provided. That is, for example, the printing mode of the printing apparatus is not limited to a printing mode of only a mainstream color such as black, but may be any of integrally forming a printing head or a combination of a plurality of printing heads. The present invention is also very effective for an apparatus provided with at least one of the recording modes of full color by color mixture.

In addition, in the embodiments of the present invention described above, the ink is described as a liquid. However, an ink which solidifies at room temperature or lower and which softens or liquefies at room temperature may be used. In general, the ink jet method generally controls the temperature of the ink itself within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range. Sometimes, the ink may be in a liquid state. In addition, in order to positively prevent temperature rise due to thermal energy by using it as energy for changing the state of the ink from a solid state to a liquid state, or to prevent evaporation of the ink, the ink is solidified in a standing state and heated. May be used. In any case, the application of heat energy causes the ink to be liquefied by the application of the heat energy according to the recording signal and the liquid ink to be ejected, or to start solidifying when it reaches the recording medium. The present invention is also applicable to a case where an ink having a property of liquefying for the first time is used. In such a case, the ink
JP-A-54-56847 or JP-A-60-7
As described in Japanese Patent Publication No. 1260, it is also possible to adopt a form in which the sheet is opposed to the electrothermal converter in a state where it is held as a liquid or solid substance in the concave portion or through hole of the porous sheet. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, the form of the ink jet recording apparatus of the present invention is not only used as an image output terminal of an information processing apparatus such as a computer, but also for a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmission / reception function. It may take a form.

[0040]

As described above, according to the present invention,
By performing the cleaning process for eliminating the clogging of the nozzles of the inkjet head that ejects the ink only for the nozzles that are actually clogged, an excellent amount of ink consumption required for the cleaning process can be minimized. The effect can be achieved.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a perspective view illustrating an example of an inkjet head.

FIG. 3 is a cross-sectional view of one head taken along line XX of FIG. 2;

FIG. 4 is a perspective view showing an example of a head unit in which the ink jet head and the ink tank shown in FIGS. 2 and 3 are integrated.

FIG. 5 is a perspective view showing a printing apparatus to which an inkjet head or a head unit can be detachably attached.

FIG. 6 is a flowchart illustrating an operation of the image forming apparatus illustrated in FIG. 1;

FIG. 7 is a schematic diagram illustrating a result of a printing process.

FIG. 8 is a schematic diagram illustrating a result of a printing process.

FIG. 9 is a schematic diagram illustrating an example of display of clogged nozzle selection in the case of a color head cartridge.

FIG. 10 is a schematic diagram showing an example of a display of clogged nozzle selection in the case of a monochrome head cartridge.

FIG. 11 is a schematic diagram showing an example of an arrangement configuration of ejection openings of a head in a color cartridge.

[Explanation of symbols]

HD head TA ink tank HU head unit HC head cartridge 1 control unit (head control unit) 2 ROM 3 RAM 4 external ROM 5 keyboard control unit 6 keyboard (specifying unit) 7 display control unit 8 display unit (display unit) 9 peripheral device Control device 10 Floppy disk drive device 11 Hard disk drive device 12 Printing device 13 Pointing device (specifying means) 110 Substrate 111 Ink ejection port 112 First head 113 Ink ejection port 114 Second head 115 Top plate 117 Heater board 118 Ink flow path 119 Ink liquid chamber 120 Ink introduction path 121 Wiring board 122 Elastic member 123 Concave section 130 Carriage 131 Chassis 132 Scan rail 133 Scan rail 134 Drive belt 135 Flexible Buru 136 protective cap (cleaning means: capping means)

Claims (10)

[Claims] 1. An image forming apparatus that forms an image using an inkjet head that ejects ink toward a recording medium, wherein the inkjet head is provided with one end to the other end of a plurality of nozzles of the inkjet head. A head control means for sequentially ejecting ink for each nozzle to draw a straight line, and printing a print check pattern with equal intervals between the straight lines; and the printing formed by being controlled by the head control means. An image forming apparatus comprising: a selection unit that selects a nozzle to be cleaned based on a result of a check pattern; and a cleaning unit that performs a cleaning process only on the nozzle selected by the selection unit. 2. The apparatus according to claim 1, wherein said selection means includes display means for individually displaying all nozzles, and identification means for individually identifying all nozzles displayed by said display means. Image forming device. 3. The image forming apparatus according to claim 2, wherein the display unit has a flat or substantially flat display area. 4. The image forming apparatus according to claim 3, wherein the specifying unit is a pointing device that indicates a specific part in the display area of the display unit. 5. The cleaning device according to claim 1, wherein the cleaning device includes a capping device that covers all nozzles of the inkjet head, and a pump device that creates a negative pressure in a space between the capping device and the inkjet head. Item 2. The image forming apparatus according to Item 1. 6. The image forming apparatus according to claim 5, wherein the capping unit has a tube for removing waste ink from a nozzle of the inkjet head. 7. The ink-jet head includes an ink discharge port forming a nozzle and an ink flow path communicating with the ink discharge port, and the ink flow path has energy sufficient to discharge ink. 2. The image forming apparatus according to claim 1, further comprising a heat energy generator for applying heat energy. 8. The image forming apparatus according to claim 7, wherein the thermal energy generator is an electrothermal converter that causes film boiling of the ink. 9. The image forming apparatus according to claim 7, wherein the ink discharge port is provided at a position facing the thermal energy generator. 10. The image forming apparatus according to claim 7, wherein the ink ejection port is provided on an extension of a direction along a surface of the thermal energy generator.