Image formation device and adjustment method

Abstract

To provide an image formation device and an adjustment method which can suppress deterioration of a sheet for adjustment that is used for adjusting an image reading part.SOLUTION: An image formation device 100 comprises: an image formation part 2 that forms an ink image on a sheet being conveyed along a conveying path; a heating part 4 that heats the sheet having the ink image formed thereon by the image formation part 2; an image reading part 5 that reads out the ink image formed on the sheet by the image formation part 2; a conveyance processing part 61 that executes conveyance processing for conveying the sheet for adjustment along the conveying path while stopping driving of the heating part 4; a reading processing part 62 that reads out an image of the sheet for adjustment being conveyed by the conveyance processing, using the image reading part 5; and an adjustment processing part 63 that adjusts the image reading part 5, on the basis of a read result by the reading processing part 62.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an image forming apparatus and an adjustment method.

Background Art

[0002] An image forming apparatus is known that includes an image forming unit that forms an image on a sheet conveyed along a predetermined conveyance path, a heating unit that heats the sheet on which the image has been formed by the image forming unit in the conveyance path, and an image reading unit that reads the image formed on the sheet by the image forming unit in the conveyance path (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in an image forming apparatus including the image reading unit, it is conceivable to convey a calibration sheet on which a calibration image for adjusting the image reading unit is pre-formed along the conveyance path, and to adjust the image reading unit based on the reading result of the calibration image by the image reading unit. However, when the calibration sheet is conveyed while the heating unit is driven, the calibration sheet deteriorates.

[0005] An object of the present invention is to provide an image forming apparatus and an adjustment method capable of suppressing deterioration of a calibration sheet used for adjusting an image reading unit.

Means for Solving the Problems

[0006] An image forming apparatus according to one aspect of the present invention includes an image forming unit, a heating unit, an image reading unit, a conveyance processing unit, a reading processing unit, and an adjustment processing unit. The image forming unit forms an ink image on a sheet conveyed along a predetermined conveyance path. The heating unit heats the sheet on which the ink image is formed by the image forming unit in the conveyance path. The image reading unit reads the ink image formed on the sheet by the image forming unit in the conveyance path. The conveyance processing unit executes a conveyance process of conveying an adjustment sheet on which a predetermined adjustment image is previously formed along the conveyance path without forming the ink image in a state where the driving of the heating unit is stopped. The reading processing unit reads the adjustment image of the adjustment sheet conveyed by the conveyance process using the image reading unit. The adjustment processing unit adjusts the image reading unit based on the reading result by the reading processing unit.

[0007] An adjustment method according to another aspect of the present invention is executed in an image forming apparatus including an image forming unit that forms an ink image on a sheet conveyed along a predetermined conveyance path, a heating unit that heats the sheet on which the ink image is formed by the image forming unit in the conveyance path, and an image reading unit that reads the ink image formed on the sheet by the image forming unit in the conveyance path, and includes a conveyance step, a reading step, and an adjustment step. In the conveyance step, a conveyance process of conveying an adjustment sheet on which a predetermined adjustment image is previously formed along the conveyance path without forming the ink image in a state where the driving of the heating unit is stopped is executed. In the reading step, the adjustment image of the adjustment sheet conveyed by the conveyance process is read using the image reading unit. In the adjustment step, the image reading unit is adjusted based on the reading result in the reading step.

Advantages of the Invention

[0008] According to the present invention, it is possible to suppress deterioration of an adjustment sheet used for adjusting an image reading unit.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

[0010] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Note that the following embodiments are merely examples of embodying the present invention and do not limit the technical scope of the present invention.

[0011] [Configuration of Image Forming Apparatus 100] First, with reference to FIGS. 1 to 3, the configuration of an image forming apparatus 100 according to an embodiment of the present invention will be described. In FIG. 2, the first sheet conveyance path 13 and the second sheet conveyance path 14 are indicated by a two-dot chain line. Also, in FIG. 2, the cap unit 3 disposed at the cap position P3 is indicated by a broken line.

[0012] The image forming apparatus 100 is a printer capable of forming an image on a sheet by an inkjet method. Note that the present invention may be applied to image forming apparatuses such as a facsimile apparatus, a copying machine, and a multifunction machine capable of forming an image on a sheet by an inkjet method.

[0013] As shown in FIGS. 1 and 2, the image forming apparatus 100 includes a sheet conveyance unit 1, an image forming unit 2, a cap unit 3, a heating unit 4, an image reading unit 5, an operation display unit 6, a control unit 7, and a housing 8.

[0014] The housing 8 houses each component of the image forming apparatus 100. In the housing 8, each of a plurality of paper feed cassettes 11 shown in FIG. 2 is detachably provided. In each of the paper feed cassettes 11, a sheet on which an image is to be formed is placed. As shown in FIG. 2, three paper feed cassettes 11 (11A, 11B, 11C) are provided in the housing 8. On the outer surface of the housing 8, a paper discharge tray 12 shown in FIG. 2 is provided. In the paper discharge tray 12, a sheet on which an image is formed by the image forming unit 2 is discharged. Note that the number of paper feed cassettes 11 provided in the housing 8 is not limited to three.

[0015] As shown in FIG. 2, inside the housing 8, a first sheet conveyance path 13 and a second sheet conveyance path 14 for guiding a sheet conveyed by the sheet conveyance unit 1 are provided. The first sheet conveyance path 13 is a movement path of a sheet that reaches the paper discharge tray 12 from the vicinity of the three paper feed cassettes 11 via the image forming unit 2 and the heating unit 4. In the first sheet conveyance path 13, the sheet is conveyed in a first conveyance direction D1 (see FIG. 2) toward the paper discharge tray 12. The second sheet conveyance path 14 is used for inverting a sheet on which an image is formed on a first surface (an example of a specific surface of the present invention). The first surface faces the upper side of the sheet placed in the paper feed cassette 11. The second sheet conveyance path 14 branches from a branch position P1 (see FIG. 2) on the downstream side of the heating unit 4 in the first conveyance direction D1 in the first sheet conveyance path 13, and merges at a merge position P2 (see FIG. 2) on the upstream side of the image forming unit 2 in the first sheet conveyance path 13 in the first conveyance direction D1. In the second sheet conveyance path 14, the sheet is conveyed in a second conveyance direction D2 (see FIG. 2) toward the merge position P2. The second sheet conveyance path 14 is an example of the inversion conveyance path of the present invention.

[0016] The sheet conveyance unit 1 conveys a sheet inside the housing 8. As shown in FIG. 2, the sheet conveyance unit 1 includes a plurality of pickup rollers 21, a plurality of first conveyance roller pairs 22, and a plurality of second conveyance roller pairs 23.

[0017] A plurality of pickup rollers 21 are provided corresponding to the plurality of paper feed cassettes 11. Each of the pickup rollers 21 takes out one sheet from the corresponding paper feed cassette 11 and sends out the taken-out sheet to the first sheet conveyance path 13. A plurality of first conveyance roller pairs 22 are provided side by side along the first sheet conveyance path 13. Each of the first conveyance roller pairs 22 conveys the sheet in the first conveyance direction D1 (see FIG. 2). Among the plurality of first conveyance roller pairs 22, the first conveyance roller pair 22A (see FIG. 2) provided at the most downstream in the first conveyance direction D1 reversely rotates at the timing after the rear end of the conveyed sheet passes through the branch position P1, thereby sending out the sheet to the second sheet conveyance path 14. A plurality of second conveyance roller pairs 23 are provided side by side along the second sheet conveyance path 14. Each of the second conveyance roller pairs 23 conveys the sheet in the second conveyance direction D2 (see FIG. 2).

[0018] In the image forming apparatus 100, when a single-sided image forming process for forming an image on one side (the first side) of the sheet placed on the paper feed cassette 11 is executed, the sheet is conveyed along the first conveyance path that reaches the paper discharge tray 12 without passing through the second sheet conveyance path 14. The first conveyance path is a path that reaches the paper discharge tray 12 via the first sheet conveyance path 13. Further, in the image forming apparatus 100, when a double-sided image forming process for forming images on both sides (the first side and the second side on the back side of the first side) of the sheet accommodated in the paper feed cassette 11 is executed, the sheet is conveyed along the second conveyance path that reaches the paper discharge tray 12 via the second sheet conveyance path 14. The second conveyance path is a path that reaches the paper discharge tray 12 via the first sheet conveyance path 13 and the second sheet conveyance path 14 and then via the first sheet conveyance path 13 again. The plurality of paper feed cassettes 11 are an example of the plurality of sheet placement portions of the present invention. Further, the second conveyance path is an example of the specific conveyance path of the present invention.

[0019] The image forming unit 2 forms an ink image on the sheet conveyed along the first conveyance path or the second conveyance path. As shown in FIG. 3, the image forming unit 2 includes line heads 31 to 34 corresponding to the respective colors of black, cyan, magenta, and yellow, and a head frame 35 that supports them. The head frame 35 is supported by the housing 8. Note that the number of line heads provided in the image forming unit 2 is not limited to four.

[0020] As shown in FIG. 3, the line heads 31 to 34 are long in the width direction D3 orthogonal to the first conveyance direction D1. Specifically, each of the line heads 31 to 34 has a length corresponding to the width of the largest-sized sheet among the sheets that can be accommodated in the paper feed cassette 11 in the width direction D3. Each of the line heads 31 to 34 is fixed to the head frame 35 at a predetermined interval along the first conveyance direction D1.

[0021] As shown in FIG. 3, each of the line heads 31 to 34 has a plurality of recording heads 30. Each of the recording heads 30 discharges ink toward the sheet conveyed by the sheet conveyance unit 1. Specifically, a plurality of nozzles 30A (see FIG. 3) for ink discharge having openings are provided on the opposing surface of each of the recording heads 30 with respect to the conveyed sheet. Further, each of the recording heads 30 includes a pressure chamber (not shown) corresponding to each of the nozzles 30A, a piezoelectric element (not shown) provided corresponding to each of the pressure chambers, and a communication flow path (not shown) communicating with each of the pressure chambers. The piezoelectric element discharges ink from the nozzle 30A in response to the application of a predetermined drive voltage. Specifically, the piezoelectric element discharges ink from the nozzle 30A by pressurizing the ink accommodated in the pressure chamber.

[0022] As shown in FIG. 3, in line head 31, three recording heads 30 are arranged in a staggered pattern along the width direction D3. Also, in each of line heads 32 to 34, similar to line head 31, three recording heads 30 are arranged in a staggered pattern along the width direction D3. Ink of the same color as the color corresponding to each of line heads 31 to 34 is supplied to each of line heads 31 to 34 from an ink container (not shown).

[0023] The cap portion 3 is provided so as to be movable between a cap position P3 (see FIG. 2) that caps all the nozzles 30A (see FIG. 3) included in the image forming portion 2 and a retracted position P4 (see FIG. 2) retracted from the cap position P3. The cap position P3 is a position below the image forming portion 2. The retracted position P4 is a position downstream of the cap position P3 in the first conveyance direction D1. For example, the cap portion 3 is formed in a tray shape having an opposing surface that opposes the lower surfaces of each of line heads 31 to 34.

[0024] The heating portion 4 heats the sheet on which the ink image is formed by the image forming portion 2 in the first sheet conveyance path 13. The heating portion 4 dries the ink adhering to the sheet by heating the sheet on which the ink image is formed. As shown in FIG. 2, the heating portion 4 is provided downstream of the image forming portion 2 in the first conveyance direction D1 in the first sheet conveyance path 13. Also, the heating portion 4 is provided above the sheet conveyed along the first sheet conveyance path 13.

[0025] For example, the heating portion 4 includes a heat source that emits infrared rays in response to power supply, a reflector that reflects the infrared rays emitted from the heat source downward above the heat source, and a warm air fan that blows air downward above the reflector. The heating portion 4 heats the sheet by blowing warm air onto the sheet from above the sheet conveyed along the first sheet conveyance path 13. Note that the heating portion 4 is not limited to the above-described configuration, and any configuration may be used as long as it can heat the sheet conveyed along the first sheet conveyance path 13.

[0026] The image reading unit 5 reads the ink image formed on the sheet by the image forming unit 2 in the second sheet conveyance path 14. The reading result by the image reading unit 5 is used for adjusting the image forming conditions by the image forming unit 2 and the like.

[0027] As shown in FIGS. 1 and 2, the image reading unit 5 includes a line sensor 41 and an AFE (analog front end) circuit 42.

[0028] As shown in FIG.  2, the line sensor 41 is provided in the second sheet conveyance path 14. Further, the line sensor 41 is provided above the sheet conveyed along the second sheet conveyance path 14. That is, the line sensor 41 faces the first surface of the sheet conveyed along the second sheet conveyance path 14. The line sensor 41 can read an image for one line along the main scanning direction in the same direction as the width direction D3 (see FIG. 3) from the sheet passing through the arrangement position of the line sensor 41 in the second sheet conveyance path 14. For example, the line sensor 41 is a CIS (contact image sensor). The line sensor 41 includes a plurality of imaging elements arranged side by side in the width direction D3. Each of the imaging elements includes a light emitting unit and a light receiving unit. The light emitting unit emits light toward the sheet conveyed along the second sheet conveyance path 14. The light receiving unit is provided so as to be able to receive the light emitted from the light emitting unit and reflected by the sheet conveyed along the second sheet conveyance path 14, and outputs an analog electrical signal according to the amount of received light. The line sensor 41 outputs an analog electrical signal corresponding to an image for one line along the main scanning direction at a predetermined interval according to the control signal input from the control unit 7.

[0029] The AFE circuit 42 is an electronic circuit that performs predetermined processing on the analog electrical signal output from the line sensor 41. Specifically, the AFE circuit 42 includes a signal conversion unit that converts the analog electrical signal output from the line sensor 41 into a digital electrical signal (image data). Further, the AFE circuit 42 includes an image processing unit that performs predetermined image processing such as shading correction on the image data output from the signal conversion unit. The AFE circuit 42 outputs the image data after the image processing is executed from the image processing unit to the control unit 7.

[0030] The operation display unit 6 has a display unit such as a liquid crystal display that displays various information in response to a control instruction from the control unit 7, and an operation key that inputs various information to the control unit 7 in response to a user's operation, or an operation unit such as a touch panel.

[0031] The control unit 7 includes control devices such as a CPU 51, a ROM 52, and a RAM 53. The CPU 51 is a processor that executes various arithmetic processes. The ROM 52 is a non-volatile storage device in which information such as a control program for causing the CPU 51 to execute various processes is stored in advance. The RAM 53 is a volatile or non-volatile storage device used as a temporary storage memory (working area) for various processes executed by the CPU 51. The CPU 51 executes various control programs stored in advance in the ROM 52. Thereby, the CPU 51 comprehensively controls the image forming apparatus 100. Note that the control unit 7 may be configured by an electronic circuit such as an integrated circuit (ASIC). Further, the control unit 7 may be provided separately from the main control unit that comprehensively controls the image forming apparatus 100.

[0032] By the way, in an image forming apparatus including the image reading unit 5, it is conceivable to convey a calibration sheet on which a calibration image for adjusting the image reading unit 5 is pre-formed along the second conveyance path, and to adjust the image reading unit 5 based on the reading result of the calibration image by the image reading unit 5. However, when the calibration sheet is conveyed in a state where the heating unit 4 is driven, the calibration sheet deteriorates.

[0033] On the other hand, in the image forming apparatus 100 according to the embodiment of the present invention, as will be described below, it is possible to suppress the deterioration of the adjustment sheet used for the adjustment of the image reading unit 5.

[0034] Specifically, in the ROM 52 of the control unit 7, an adjustment program for causing the CPU 51 to function as the conveyance processing unit 61, the reading processing unit 62, and the adjustment processing unit 63 shown in FIG. 1 is stored in advance. The CPU 51 functions as each of the above-described processing units by executing the adjustment program. The adjustment program is recorded on a computer-readable recording medium such as a CD, a DVD, and a flash memory, and may be read from the recording medium and stored in a nonvolatile storage device provided in the image forming apparatus 100. Further, the adjustment program may be a program for causing a plurality of processors to function as each of the processing units shown in FIG. 1. Further, some or all of the processing units included in the control unit 7 may be configured by electronic circuits.

[0035] The conveyance processing unit 61 executes a conveyance process of conveying the adjustment sheet on which the adjustment image, which is a predetermined adjustment image formed in advance without forming an ink image, is formed along the second conveyance path in a state where the driving of the heating unit 4 is stopped. The adjustment sheet is a sheet on which the adjustment image is formed on the first surface. For example, the adjustment image includes a strip-shaped single-color image that is long in the width direction D3.

[0036] Here, in the conveyance process, the adjustment sheet is conveyed in a state where the cap unit 3 is disposed at the cap position P3 (see FIG. 2). Thereby, it is possible to avoid the adjustment sheet from being soiled (deteriorated) by the ink dripping from the nozzles 30A.

[0037] Also, in the conveyance process, the adjustment sheet is conveyed at a specific conveyance speed slower than the conveyance speed of the sheet in the image formation process of forming an ink image on the sheet using the image forming unit 2. Thereby, it is possible to suppress damage to the adjustment sheet caused by contact between the adjustment sheet conveyed along the second conveyance path and the members arranged in the second conveyance path. For example, in the image formation process, the sheet is conveyed at a predetermined first speed. Also, in the conveyance process, the sheet is conveyed at a second speed that is half of the first speed. Note that the specific conveyance speed in the case where there are a plurality of conveyance speeds of the sheet in the image formation process may be a speed slower than the slowest conveyance speed among the plurality of conveyance speeds in the image formation process.

[0038] Also, in the conveyance process, among the plurality of paper feed cassettes 11, the adjustment sheet is conveyed from a specific paper feed cassette (an example of the specific sheet placement unit of the present invention) having the shortest distance along the second conveyance path to the image forming unit 2. Thereby, since the conveyance distance of the adjustment sheet becomes shorter, it is possible to reduce the chance of the adjustment sheet being damaged during the conveyance of the adjustment sheet accordingly. The specific paper feed cassette is determined in advance based on the arrangement position of each paper feed cassette 11 in the first sheet conveyance path 13. The specific paper feed cassette in the image forming apparatus 100 is the paper feed cassette 11A (see FIG. 2).

[0039] For example, the conveyance processing unit 61 causes the operation display unit 6 to display a predetermined guidance screen in response to a predetermined user operation on the operation display unit 6. For example, the guidance screen includes a message for guiding the user to place the adjustment sheet on the paper feed cassette 11A with the adjustment image facing upward and then operate the execution key included in the guidance screen.

[0040] When the transport processing unit 61 receives a user operation on the execution key, it stops the driving of the heating unit 4 and moves the cap unit 3 to the cap position P3 (see FIG. 2). Then, after the cap unit 3 has been moved to the cap position P3 and a predetermined standby time has elapsed since the driving of the heating unit 4 was stopped, the transport processing unit 61 executes the transport processing. For example, the transport processing is realized by executing a printing job of printing a blank paper image on both sides of a sheet (that is, printing no image). Here, when the cap unit 3 is arranged at the cap position P3 when the transport processing unit 61 receives a user operation on the execution key, the cap unit 3 does not need to be moved. Also, when the heating unit 4 is stopped when the transport processing unit 61 receives a user operation on the execution key, the transport processing unit 61 may immediately execute the transport processing after the cap unit 3 has been moved to the cap position P3.

[0041] In addition, when the paper feed cassette 11A is not mounted on the housing 8, the transport processing unit 61 may cause the operation display unit 6 to display a first error screen including a message indicating that the paper feed cassette 11A is not mounted, instead of executing the transport processing. Also, when the size of the sheet placed on the paper feed cassette 11A does not match the size of the adjustment sheet stored in the ROM 52 in advance, the transport processing unit 61 may cause the operation display unit 6 to display a second error screen including a message indicating that the adjustment sheet is not placed on the paper feed cassette 11A, instead of executing the transport processing. The size of the sheet placed on the paper feed cassette 11A may be determined by a well-known method. Also, when no sheet is placed on the paper feed cassette 11A, the transport processing unit 61 may cause the operation display unit 6 to display the second error screen, instead of executing the transport processing. Also, when a paper jam occurs during the execution of the transport processing, the transport processing unit 61 may cause the guidance screen to be displayed on the operation display unit 6 again after the paper jam has been resolved.

[0042] The reading processing unit 62 reads the adjustment image of the adjustment sheet conveyed by the transport processing using the image reading unit 5.

[0043] The adjustment processing unit 63 adjusts the image reading unit 5 based on the reading result by the reading processing unit 62.

[0044] For example, the adjustment processing unit 63 adjusts the emission light amount of each of the imaging elements included in the line sensor 41 based on the reading result by the reading processing unit 62. Further, the adjustment processing unit 63 may adjust the execution conditions of the image processing executed by the image processing unit of the AFE circuit 42 based on the reading result by the reading processing unit 62.

[0045] [Adjustment Processing] Hereinafter, with reference to FIG. 4, an example of the procedure of the adjustment processing executed by the control unit 7 in the image forming apparatus 100 will be described together with the procedure of the adjustment method of the present invention. Here, steps S11, S12,... represent the numbers of the processing procedures (steps) executed by the control unit 7. Note that the adjustment processing is executed when a user operation instructing the execution of the adjustment processing is received on the operation display unit 6.

[0046] <Step S11> First, in step S11, the control unit 7 causes the operation display unit 6 to display the guidance screen.

[0047] <Step S12> In step S12, the control unit 7 determines whether or not a user operation on the execution key included in the guidance screen has been received.

[0048] Here, when the control unit 7 determines that a user operation on the execution key has been received (Yes side of S12), the process proceeds to step S13. If a user operation on the execution key has not been received (No side of S12), the control unit 7 waits for a user operation on the execution key in step S12.

[0049] <Step S13> In step S13, the control unit 7 stops the driving of the heating unit 4.

[0050] <Step S14> In step S14, the control unit 7 moves the cap unit 3 to the cap position P3 (see FIG. 2).

[0051] <Step S15> In step S15, the control unit 7 determines whether or not the waiting time has elapsed since the drive of the heating unit 4 stopped.

[0052] Here, when the control unit 7 determines that the waiting time has elapsed (Yes side in S15), the process proceeds to step S16. Also, if the waiting time has not elapsed (No side in S15), the control unit 7 waits for the waiting time to elapse in step S15.

[0053] <Step S16> In step S16, the control unit 7 executes the conveyance process. The processes of steps S11 to S16 are an example of the conveyance step of the present invention and are executed by the conveyance processing unit 61 of the control unit 7.

[0054] <Step S17> In step S17, the control unit 7 reads an image of the sheet conveyed by the conveyance process (the adjustment image of the adjustment sheet) using the image reading unit 5. The process of step S17 is an example of the reading step of the present invention and is executed by the reading processing unit 62 of the control unit 7.

[0055] <Step S18> In step S18, the control unit 7 adjusts the image reading unit 5 based on the reading result by the reading processing unit 62. The process of step S18 is an example of the adjustment step of the present invention and is executed by the adjustment processing unit 63 of the control unit 7.

[0056] As described above, in the image forming apparatus 100, the conveyance process of conveying the adjustment sheet along the second conveyance path is executed while the driving of the heating unit 4 is stopped. Thereby, deterioration of the adjustment sheet can be suppressed as compared with a configuration in which the adjustment sheet is conveyed while the heating unit 4 is driven.

[0057] Further, in the image forming apparatus 100, the adjustment sheet is conveyed along the second conveyance path. As a result, the adjustment sheet with the adjustment image facing downward is discharged to the paper discharge tray 12. Therefore, fading due to sunlight or the like can be suppressed as compared with a configuration in which the adjustment sheet with the adjustment image facing upward is discharged to the paper discharge tray 12.

[0058] Note that the conveyance process may be a process of conveying the adjustment sheet regardless of the arrangement position of the cap unit 3.

[0059] Further, the conveyance process may be a process of conveying the adjustment sheet at the same speed as the conveyance speed of the sheet in the image forming process.

[0060] Further, the conveyance process may be a process of conveying the adjustment sheet from an arbitrary paper feed cassette 11.

[0061] Further, the image reading unit 5 may be disposed on the first sheet conveyance path 13. For example, the image reading unit 5 may be disposed on the downstream side in the first conveyance direction D1 of the heating unit 4 in the first sheet conveyance path 13. In this case, the conveyance process may be a process of conveying the adjustment sheet along the first conveyance path. Further, the image forming apparatus 100 may not include the second sheet conveyance path 14.

[0062] [Supplementary Note of the Invention] Hereinafter, an outline of the invention extracted from the above-described embodiment will be appended. Note that each configuration and each processing function described in the following supplementary note can be arbitrarily combined by making selections.

[0063] <Supplementary Note 1> An image forming apparatus including: an image forming unit that forms an ink image on a sheet conveyed along a predetermined conveyance path; a heating unit that heats the sheet on which the ink image is formed by the image forming unit in the conveyance path; an image reading unit that reads the ink image formed on the sheet by the image forming unit in the conveyance path; a conveyance processing unit that executes a conveyance process of conveying an adjustment sheet on which a predetermined adjustment image is previously formed along the conveyance path without forming the ink image in a state where driving of the heating unit is stopped; a reading processing unit that reads the adjustment image of the adjustment sheet conveyed by the conveyance process using the image reading unit; and an adjustment processing unit that adjusts the image reading unit based on a reading result by the reading processing unit.

[0064] <Appendix 2> The image forming unit has nozzles that eject ink onto the sheet, and the image forming apparatus includes a cap unit that is movably provided between a cap position that caps the nozzles and a retracted position that is retracted from the cap position. In the conveyance process, the adjustment sheet is conveyed in a state where the cap unit is disposed at the cap position. The image forming apparatus according to Appendix 1.

[0065] <Appendix 3> In the conveyance process, the adjustment sheet is conveyed at a specific conveyance speed that is slower than the conveyance speed of the sheet in an image forming process of forming the ink image on the sheet using the image forming unit. The image forming apparatus according to Appendix 1 or 2.

[0066] <Appendix 4> The apparatus includes a plurality of sheet placement units on which the sheet conveyed along the conveyance path is placed. In the conveyance process, the adjustment sheet is conveyed from a specific sheet placement unit that has the shortest distance along the conveyance path to the image forming unit among the plurality of sheet placement units. The image forming apparatus according to any one of Appendices 1 to 3.

[0067] <Appendix 5> An image forming apparatus according to any one of Appendices 1 to 4, comprising a reverse conveyance path used for reversing a sheet on which an ink image is formed on a specific surface by the image forming unit, the conveyance path including a specific conveyance path passing through the reverse conveyance path, the adjustment sheet being the sheet on which the adjustment image is formed on the specific surface, and in the conveyance process, the adjustment sheet being conveyed along the specific conveyance path.

[0068] <Appendix 6> An adjustment method executed by an image forming apparatus including an image forming unit that forms an ink image on a sheet conveyed along a predetermined conveyance path, a heating unit that heats the sheet on which the ink image is formed by the image forming unit in the conveyance path, and an image reading unit that reads the ink image formed on the sheet by the image forming unit in the conveyance path, the adjustment method including: a conveyance step of executing a conveyance process of conveying a adjustment sheet on which a predetermined adjustment image is previously formed along the conveyance path without forming the ink image while the driving of the heating unit is stopped; a reading step of reading the adjustment image of the adjustment sheet conveyed by the conveyance process using the image reading unit; and an adjustment step of adjusting the image reading unit based on the reading result of the reading step.

Explanation of Reference Numerals

[0069] 1 Sheet conveyance unit 2 Image forming unit 3 Cap unit 4 Heating unit 5 Image reading unit 6 Operation display unit 7 Control unit 8 Housing 11 Paper feed cassette 12 Paper discharge tray 13 First sheet conveyance path 14 Second sheet conveyance path 21 Pickup roller 22 First pair of conveyance rollers 23 Second pair of conveyance rollers 30 Recording head 30A Nozzle 31 Line Head 32 Line Head 33 Line Head 34 Line Head 35 Head Frame 41 Line Sensor 42 AFE Circuit 61 Conveying Processing Unit 62 Reading Processing Unit 63 Adjusting Processing Unit 100 Image Forming Apparatus

Claims

1. An image forming unit that forms an ink image on a sheet conveyed along a predetermined conveyance path; A heating unit that heats the sheet on which the ink image is formed by the image forming unit in the conveyance path; An image reading unit that reads the ink image formed on the sheet by the image forming unit in the conveyance path; A conveyance processing unit that executes a conveyance process of conveying an adjustment sheet on which a predetermined adjustment image is previously formed along the conveyance path without forming the ink image while the driving of the heating unit is stopped; A reading processing unit that reads the adjustment image of the adjustment sheet conveyed by the conveyance process using the image reading unit; An adjustment processing unit that adjusts the image reading unit based on a reading result by the reading processing unit; An image forming apparatus comprising the above.

2. The image forming unit has nozzles that discharge ink onto the sheet, The image forming apparatus, Comprises a cap unit that is movably provided between a cap position that caps the nozzles and a retracted position retracted from the cap position, In the conveyance process, the adjustment sheet is conveyed with the cap unit disposed at the cap position. The image forming apparatus according to claim 1.

3. In the conveyance process, the adjustment sheet is conveyed at a specific conveyance speed slower than the conveyance speed of the sheet in the image forming process of forming the ink image on the sheet using the image forming unit. The image forming apparatus according to claim 1 or 2.

4. Comprises a plurality of sheet placement units on which the sheet conveyed along the conveyance path is placed, In the conveyance process, the adjustment sheet is conveyed from a specific sheet placement unit having the shortest distance along the conveyance path to the image forming unit among the plurality of sheet placement units. The image forming apparatus according to claim 1 or 2.

5. Comprises a reverse conveyance path used for reversing the sheet on which the ink image is formed on a specific surface by the image forming unit, The conveyance path includes a specific conveyance path passing through the reverse conveyance path, The adjustment sheet is a sheet on which the adjustment image is formed on the specific surface, In the conveyance process, the adjustment sheet is conveyed along the specific conveyance path. The image forming apparatus according to claim 1 or 2.

6. An image forming apparatus including an image forming unit that forms an ink image on a sheet conveyed along a predetermined conveyance path, a heating unit that heats the sheet on which the ink image is formed by the image forming unit in the conveyance path, and an image reading unit that reads the ink image formed on the sheet by the image forming unit in the conveyance path, and a method for adjustment executed by the image forming apparatus, a conveyance step of executing a conveyance process of conveying a adjustment sheet on which a predetermined adjustment image is previously formed without forming the ink image in a state where driving of the heating unit is stopped along the conveyance path, a reading step of reading the adjustment image of the adjustment sheet conveyed by the conveyance process using the image reading unit, an adjustment step of adjusting the image reading unit based on a reading result of the reading step, and an adjustment method including the above steps.

Images