JP2011230460A - Image forming apparatus and discharge head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify processing in the replacement of a discharge head.SOLUTION: IC chips 27a-27c for storing the impact position information and discharge amount information are provided at each of printheads 26a-26c. When receiving a print job, print data is created by reflecting the impact position information and the discharge amount information stored in the IC chips 27a-27c. Also, an ink drop is discharged from the nozzles of the printheads 26a-26c by using the created print data.

Description

  The present invention relates to an image forming apparatus and an ejection head.

  2. Description of the Related Art Conventionally, an image forming apparatus includes a plurality of print heads arranged along a main scanning direction in which a print head is reciprocated, and each print region is divided into a plurality of regions along the main scanning direction. On the other hand, when ink is ejected from each corresponding print head, a print shift in the sub-scanning direction of an image recorded in each print area occurs due to a position shift of each print head in the sub-scanning direction orthogonal to the main scanning direction. In this case, there has been proposed one that adjusts the timing of each print data supplied to each print head according to a correction value determined according to the amount of print misalignment (see, for example, Patent Document 1). In this apparatus, a test pattern including a plurality of color patches is printed before or after shipment from the operator's request, and correction values selected by the operator from the printed test patterns are stored in the EEPROM of the apparatus. By adjusting the timing of each print data in accordance with this correction value during printing, printing deviation caused by positional deviation in the sub-scanning direction between a plurality of print heads is suppressed.

JP 2004-284124 A

  However, in the above-described image forming apparatus, when the print head is replaced after shipment, the operator needs to instruct printing of the test pattern and reselect the correction value from the print result after the replacement. In order to improve the convenience of the operator, it is preferable that such processing at the time of replacing the print head can be omitted as much as possible.

  The main object of the image forming apparatus and the ejection head of the present invention is to simplify the process when replacing the ejection head.

  The image forming apparatus and the ejection head of the present invention employ the following means in order to achieve the above-described main object.

The image forming apparatus of the present invention includes:
An image forming apparatus that forms an image by discharging liquid onto a medium from nozzles of a plurality of discharge heads mounted on a mounting unit,
A plurality of recording means provided in each of the plurality of ejection heads, in which landing position information, which is information relating to a landing position of the liquid ejected from the nozzle, is recorded;
When image data is received and image formation is instructed, the landing position information about the nozzles of the corresponding discharge heads recorded in each of the plurality of recording units is reflected in the image data and used for image formation Control means for controlling the plurality of ejection heads such that liquid is ejected from the nozzles of the plurality of ejection heads to the medium based on the created formation data.
It is a summary to provide.

  In the image forming apparatus of the present invention, a plurality of recording means for recording landing position information, which is information related to the landing position of the liquid discharged from the nozzles, is provided in each of the plurality of discharge heads, and receives image data and receives image data. When formation is instructed, the formation position data for image formation is created by reflecting the landing position information about the nozzles of the corresponding ejection heads recorded in each of the plurality of recording units on the image data. Based on the formation data, the plurality of ejection heads are controlled such that liquid is ejected from the nozzles of the plurality of ejection heads to the medium. Accordingly, by providing each of the plurality of ejection heads with a plurality of recording means for recording the landing position information, it is not necessary to perform a process for confirming the landing position every time the ejection head is replaced, and processing when replacing the ejection head Can be simplified. Of course, image formation deviation can be suppressed by creating formation data reflecting the landing position information and discharging liquid from the nozzles of a plurality of discharge heads.

  In such an image forming apparatus of the present invention, the recording unit is a unit that records discharge amount information, which is information related to the discharge amount of the liquid discharged from the nozzle, in addition to the landing position information. The landing data and the ejection amount information recorded in the plurality of recording units may be reflected on the image data to create the formation data. By so doing, it is possible to further suppress image formation deviation.

  The image forming apparatus according to the present invention further includes a recording processing unit that records arrangement position information, which is information relating to an arrangement position of the ejection head, on the recording unit when the ejection head is attached to the carriage. You can also

  Furthermore, in the image forming apparatus of the present invention, the plurality of recording units may be a plurality of storage media that electromagnetically store information, or the plurality of recording units may be images indicating information. Can be printed on each of the plurality of ejection heads, or an image indicating information can be printed on a sticker attached to each of the plurality of ejection heads.

The discharge head of the present invention is
When a plurality of ejection heads mounted on the mounting unit and image data are received and an image formation is instructed, the image data is used to create image formation data and based on the created formation data A control unit that controls the plurality of discharge heads such that liquid is discharged onto a medium from nozzles of the plurality of discharge heads,
Recording means for recording landing position information, which is information used when creating the formation data and is information related to the landing position of the liquid ejected from the nozzle,
It is a summary to provide.

  The discharge head according to the present invention includes a plurality of recording means for recording landing position information that is information used when creating formation data and is information related to the landing position of the liquid discharged from the nozzle. Thereby, it is not necessary to perform the process of confirming the landing position every time the ejection head is replaced, and the process at the time of replacing the ejection head can be simplified.

1 is a configuration diagram showing an outline of the configuration of an inkjet printer 20. FIG. 2 is a configuration diagram showing an outline of the configuration of a print head unit 24. The block diagram which shows the outline of a structure of the mounting part 25. FIG. Explanatory drawing which shows an example of a target position and an actual landing position. 6 is a flowchart illustrating an example of a print processing routine.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing an outline of the configuration of an ink jet printer 20 which is an embodiment of the image forming apparatus of the present invention, FIG. 2 is a configuration diagram showing an outline of the configuration of a print head unit 24, and FIG. FIG. 6 is a configuration diagram showing an outline of a configuration of a mounting unit 25.

  As shown in FIG. 1, the inkjet printer 20 of the present embodiment transports the recording paper S from the back to the front (conveying direction) on the platen 40 by driving the paper feed roller 34 by the drive motor 32. A paper feed mechanism 30; a printer mechanism 21 that performs printing by ejecting ink droplets from the print heads 26a to 26c (see FIG. 2) of the print head unit 24 onto the recording paper S conveyed by the paper feed mechanism 30; 40, a capping device 41 that is formed at the right end in the drawing and covers the print head unit 24 during printing pause.

  The printer mechanism 21 guides the carriage belt 44 that is installed between the carriage motor 42a attached to the right side of the mechanical frame 48 and the driven roller 42b attached to the left side of the mechanical frame 48 by the carriage motor 42a. 46, the carriage 22 reciprocating left and right (main scanning direction orthogonal to the transport direction) in the drawing, and inks of each color of cyan (C), magenta (M), yellow (Y), and black (K) are individually provided. And an ink cartridge 50 that can be supplied to the carriage 22 and a plurality of print heads 26a to 26c (see FIG. 2) that discharge ink droplets by pressurizing each ink supplied from the ink cartridge 50. A head unit 24. Here, a linear encoder 29 for detecting the position of the carriage 22 is disposed on the rear surface of the carriage 22, and the position of the carriage 22 can be managed using the linear encoder 29.

  As shown in FIGS. 2 and 3, the print head unit 24 includes a mounting portion 25 provided at a lower portion of the carriage 22, and arrangement positions of the mounting portion 25 (three locations in the examples of FIGS. 2 and 3) 25a to 25c. And print heads 26a to 26c, respectively, attached thereto. The lower surface of the mounting positions 25a to 25c of the mounting portion 25 is opened so that the nozzles provided on the lower surfaces of the print heads 26a to 26c to be attached are exposed. Further, the print heads 26a to 26c are of the same type, and these may adopt a system in which a voltage is applied to the piezoelectric element to deform the piezoelectric element and pressurize the ink. Alternatively, a method may be adopted in which a voltage is applied to a heating resistor (for example, a heater) to pressurize the ink with bubbles generated by heating the ink. Further, the print heads 26a to 26c are provided with IC chips 27a to 27c that can electromagnetically read and write data by the controller 70, respectively. In the following description, the print heads 26a to 26c and the same print heads (replacement print heads not mounted on the mounting unit 25) are collectively referred to simply as print heads 26, and each of these print heads 26 is provided. IC chips (IC chips 27a to 27c provided on the print heads 26a to 26c and IC chips provided on the replacement print head) may be simply referred to as an IC chip 27 in some cases. The IC chip 27 stores landing position information, which is information regarding the landing positions of the plurality of nozzles of the print head 26 to be attached, and discharge amount information, which is information regarding the ink discharge amounts of the plurality of nozzles as a whole. Yes. In the present embodiment, the landing position information is obtained by performing a test or the like in advance to store the average value of the actual landing position deviation (coordinates) with respect to the target position of each nozzle and storing it in the IC chip 27. The average value of the deviation of the actual discharge amount (discharge weight) with respect to the target discharge amount (target discharge weight) of each nozzle is obtained by performing a test or the like in advance and stored in the IC chip 27. An example of the target position and the actual landing position is shown in FIG. In the example of FIG. 4, the actual landing position is −1 with respect to the target position in the x direction (corresponding to the main scanning direction when attached to the mounting portion 25), and the y direction (when attached to the mounting portion 25). This shows a case where it is shifted by +1 in the conveyance direction). As for the print head 26 attached to the mounting unit 25 before shipment, the information acquired by the test before being mounted on the mounting unit 25 may be written in the IC chip 27 before shipment. Information acquired by a test after being mounted on the mounting unit 25 may be written into the IC chip 27. On the other hand, with respect to the replacement print head (print head shipped as a single unit) 26, information obtained by the test of the print head 26 alone is written into the IC chip 27.

  The ink cartridge 50 adopts an off-carriage type in which the ink cartridge 50 is not mounted on the carriage 22, and cyan (C), magenta (M), yellow (Y) containing a pigment as a colorant in water as a solvent. ) And black (K) printing ink containers 52a to 52d, respectively. The ink cartridge 50 can supply ink from the ink containers 52a to 52d to the carriage 22 via the supply tubes 56a to 56d. In this embodiment, the off-carriage type is used. However, an on-carriage type in which the ink cartridge 50 is mounted on the carriage 22 may be used.

  The controller 70 is configured as a microprocessor centered on the CPU 72, and includes a ROM 73 that stores various processing programs and various data, a RAM 74 that temporarily stores data, and a flash memory 75 that can write and delete data. And an interface (I / F) 76 for exchanging information with an external device, and an input / output port (not shown). The RAM 74 is provided with a print buffer area, and print jobs sent from the user PC 90, which is a general-purpose personal computer, via the I / F 76 are stored in the print buffer area. The flash memory 75 also stores arrangement position information that is information related to the arrangement positions 25a to 25c of the mounting unit 25. In this embodiment, the arrangement position information uses coordinates (0, 0), (x1, y1), (x2, y2) of the positions of the upper left corners in FIG. 3 of the arrangement positions 25a to 25c. The controller 70 receives position signals from the linear encoder 29, landing position information from the IC chips 27a to 27c, discharge amount information, and the like via an input port, and also print jobs from the user PC 90 to the I / O. Input via F76. The controller 70 outputs a drive signal to the print heads 26a to 26c attached to the mounting unit 25, a drive signal to the drive motor 32, a drive signal to the carriage motor 42a, and the like via an output port. Print status information and the like are output to the user PC 90 via the I / F 76.

  Next, the operation of the ink jet printer 20 of the present embodiment configured as described above will be described. FIG. 5 is a flowchart illustrating an example of a print processing routine executed by the CPU 72 of the controller 70. This routine is executed when a print job is received from the user PC 90.

  When the print processing routine is executed, the CPU 72 of the controller 70 first stores data such as image data (RGB) included in the print job, arrangement position information, landing position information about the print heads 26a to 26c, and discharge amount information. Is input (step S100). Here, it is assumed that the arrangement position information is read and input from the memory stored in the flash memory 75. Further, in the present embodiment, the landing position information and the discharge amount information are read and input by a reading unit (not shown) written in the IC chips 27a to 27c.

  When data is input in this way, pixels are thinned out at a predetermined rate, or the average value of each gradation value between adjacent pixels is calculated and replaced with one pixel, or a new pixel is generated by interpolation between adjacent pixels. Resolution conversion processing for converting the resolution of the image data into the resolution for printing (step S110), or color conversion processing for converting RGB data into CMYK data with reference to a color conversion lookup table (LUT) (step S110). S120), a halftone process for converting CMYK data into binarized data is performed (step S130), and the binarized data subjected to the halftone process in consideration of the arrangement position information, the landing position information, and the discharge amount information is used. Print data (raster data indicating the target formation state of dots from the print heads 26a to 26c) is created (step Flop S140), performs a printing process by using the print data generated (step S150), and terminates this routine. Here, in the printing process, the carriage motor 34a is controlled so that the carriage 22 reciprocates in the main scanning direction, and the print heads 26a to 26c are controlled so that ink is ejected onto the paper S based on the print data. This is performed by repeating the process of controlling the drive motor 32 so that S is transported by a predetermined transport amount in the transport direction. Further, the print data is created in consideration of the arrangement position information (coordinates (0, 0), (x1, y1), (x2, y2) of the arrangement positions 25a to 25c), for example, for the print head 26a. The landing position is deviated by −1 in the x direction (main scanning direction) and +1 in the y direction (conveying direction) with respect to the target position (see FIG. 4), and the actual discharge amount is predetermined with respect to the target discharge amount. When the ejection amount is larger, the target ejection amount is changed so that the portion to be printed by the print head 26a in the print data is changed by +1 in the x direction and -1 in the y direction and decreased by a predetermined ejection amount. This is done by changing the data and creating print data. By creating the print data in this manner, printing on the paper S can be performed in consideration of the nozzle displacement of each print head 26, and the print displacement due to individual differences of the print heads 26 can be suppressed. . In addition, since the IC chip 27 storing the landing position information and the discharge amount information is provided in each print head 26, after the print head 26 is replaced, the landing position information and the discharge amount information about the replaced print head 26 are obtained. There is no need to test. That is, it is possible to further simplify the processing when the print head 26 is replaced.

  Here, the correspondence between the components of the present embodiment and the components of the present invention will be clarified. The mounting portion 25 of the present embodiment corresponds to a “mounting portion”, the print head 26 (26a to 26c) corresponds to “a plurality of ejection heads”, and the IC chip 27 (27a to 27c) corresponds to “a plurality of recording units”. When the print job is received, the print data is created by considering the position information, landing position information, and discharge amount information after performing resolution conversion processing, color conversion processing, and halftone processing. The controller 70 that executes the print processing routine of FIG. 5 for performing print processing using the print data corresponds to “control means”.

  According to the ink jet printer 20 of the present embodiment described above, the IC chip 27 storing the landing position information and the discharge amount information is provided in each print head 26. Therefore, after the print head 26 is replaced, the replaced print head 26 is replaced. It is not necessary to perform a test for obtaining the landing position information and the discharge amount information. That is, it is possible to further simplify the processing when the print head 26 is replaced. In addition, print data is created reflecting the landing position information and ejection amount information stored in the IC chips 27a to 27c provided in the print heads 26a to 26c, and ink droplets are ejected from the nozzles of the print heads 26a to 26c. Since printing is performed by discharging, image formation deviation can be suppressed.

  It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that the present invention can be implemented in various modes as long as it belongs to the technical scope of the present invention.

  In the above-described embodiment, the landing position information, the discharge amount information, and the like are stored in the IC chip 27. However, any device that stores at least the landing position information may be used, and instead of or in addition to the discharge amount information. Further, arrangement position information and the like may be stored. When only the landing position information is stored in the IC chip 27, the print data may be generated in consideration of the arrangement position information and the landing position information when performing the printing process. Further, when arrangement position information is stored in the IC chip 27, this information may not be stored in the flash memory 75.

  In the above-described embodiment, the landing position information stored in the IC chip 27 is information regarding the landing positions of the plurality of nozzles of the print head 26 to be attached. However, each nozzle row (nozzles of the same color) of the print head 26 is used. Group) landing position information, or information regarding each nozzle landing position of the print head 26. In the former case, the landing position information of the number of types of ink colors (four in the above embodiment) is stored in one IC chip 27, and in the latter case, the number of nozzles is stored in one IC chip 27. Landing position information is stored. In the above-described embodiment, the discharge amount information stored in the IC chip 27 is information regarding the ink discharge amount as a whole of the plurality of nozzles of the print head 26 to be attached. Information regarding the discharge amount of the color nozzle group) or information regarding the discharge amount of each nozzle of the print head 26 may be used.

  In the embodiment described above, the arrangement position information is stored in the flash memory 75 with the coordinates (fixed values) of the arrangement positions 25a to 25c formed on the mounting unit 25, and is used when creating print data. The actual coordinates when the print head 26 is attached to the arrangement positions 25a to 25c may be stored in the flash memory 75 or the IC chip 27 and used when creating print data. In this case, when the print head 26 is replaced after shipment, it is necessary to perform processing for storing the arrangement position information in the flash memory 75 or the IC chip 27. However, the arrangement error of the print head 26 to the arrangement positions 25a to 25c is necessary. This makes it possible to create print data more appropriately.

  In the above-described embodiment, the print data is created by reflecting the landing position information and the ejection amount information with respect to the image data in the ink jet printer 20, but the landing position information with respect to the image data is created in the user PC 90. The print data may be created reflecting the discharge amount information. In this case, the user PC 90 needs to receive landing position information, ejection amount information, and the like from the inkjet printer 20. In this case, it can be considered that the ink jet printer 20 and the user PC 90 correspond to the image forming apparatus of the present invention.

  In the above-described embodiment, the IC chip 27 storing the landing position information, the discharge amount information, and the like is provided in each print head 26. However, an image (bar code or the like) indicating such information is directly displayed on the print head 26. It is good also as what prints or prints on the sticker for affixing on the print head 26. FIG. In this case, when creating print data in an inkjet printer including an image reading unit (such as a barcode reader), an image may be read by the image reading unit and used to create print data.

  In the above-described embodiment, the ink droplets are ejected from the three print heads 26a to 26c mounted on the mounting unit 25. However, the number of the print heads 26 mounted on the mounting unit 25 is not limited to three. Or may be four or more.

  In the embodiment described above, the print heads 26a to 26c are of the same type, but may be of different types. For example, each print head 26 may eject ink droplets of different colors.

  In the above-described embodiment, a method of performing printing while moving the print head unit 24 in the main scanning direction is used. However, the print head unit is formed to be long enough to fill the print area in the width direction of the print medium, and is formed in the apparatus main body. It is also possible to use a so-called line printer that performs printing while transporting only the print medium while being fixedly arranged on the printer.

  In the above-described embodiment, the print data is generated and printed using the image data received from the user PC 90. However, the print data is generated and printed using the image data stored in a memory card or the like. It may be done.

  In the embodiment described above, the inkjet printer 20 is shown as an example of the image forming apparatus of the present invention. However, the present invention forms an image by ejecting liquid onto the medium from the nozzles of a plurality of ejection heads mounted on the mounting unit. However, the present invention is not limited to this, and may be applied to OA equipment such as a facsimile machine and a multifunction machine.

  The present invention can be used in the manufacturing industry of image forming apparatuses.

  20 Inkjet printer, 21 Printer mechanism, 22 Carriage, 24 Print head unit, 25 Mount, 25a to 25c Arrangement position, 26, 26a to 26c Print head, 27, 27a to 27c IC chip, 29 Linear encoder, 30 Paper feed Mechanism, 32 drive motor, 34 paper feed roller, 40 platen, 41 capping device, 42a carriage motor, 42b driven roller, 44 carriage belt, 46 guide, 48 mechanical frame, 50 ink cartridge, 52a-52d ink container, 56a-56d Supply tube, 70 controller, 72 CPU, 73 ROM, 74 RAM, 75 flash memory, 76 interface (I / F), 90 user PC.

Claims (6)

An image forming apparatus that forms an image by discharging liquid onto a medium from nozzles of a plurality of discharge heads mounted on a mounting unit,
A plurality of recording means provided in each of the plurality of ejection heads, in which landing position information, which is information relating to a landing position of the liquid ejected from the nozzle, is recorded;
When image data is received and image formation is instructed, the landing position information about the nozzles of the corresponding discharge heads recorded in each of the plurality of recording units is reflected in the image data and used for image formation Control means for controlling the plurality of ejection heads such that liquid is ejected from the nozzles of the plurality of ejection heads to the medium based on the created formation data.
An image forming apparatus comprising: The image forming apparatus according to claim 1,
In addition to the landing position information, the recording means is means for recording discharge amount information that is information relating to the discharge amount of the liquid discharged from the nozzle,
The control means is means for creating the formation data by reflecting landing position information and discharge amount information recorded in the plurality of recording means on the image data.
Image forming apparatus. The image forming apparatus according to claim 1, wherein:
A recording processing unit that records arrangement position information, which is information relating to an arrangement position of the ejection head, on the recording unit when the ejection head is attached to the carriage;
Image forming apparatus. The image forming apparatus according to any one of claims 1 to 3,
The plurality of recording means are a plurality of storage media for electromagnetically storing information.
Image forming apparatus. The image forming apparatus according to any one of claims 1 to 3,
The plurality of recording means is an image in which information is printed on each of the plurality of ejection heads or an image in which information is printed on a sticker attached to each of the plurality of ejection heads.
Image forming apparatus. When a plurality of ejection heads mounted on the mounting unit and image data are received and an image formation is instructed, the image data is used to create image formation data, and based on the created formation data A control unit that controls the plurality of discharge heads such that liquid is discharged onto a medium from nozzles of the plurality of discharge heads,
Recording means for recording landing position information, which is information used when creating the formation data and is information related to the landing position of the liquid ejected from the nozzle,
A discharge head comprising:

Images