Image forming apparatus, adjustment method, and adjustment program

Abstract

To prevent a reduction in productivity of an image forming apparatus.SOLUTION: An image forming apparatus comprises: a first reading unit; a second reading unit that is different from the first reading unit; a first adjustment unit 123 that executes first shading processing of adjusting an output value of the first reading unit on the basis of the output value of the first reading unit; a second adjustment unit 129 that executes second shading processing of adjusting an output value of the second reading unit on the basis of the output value of the second reading unit; and a determination unit 125 that determines timing at which the first shading processing is executed and timing at which the second shading processing is executed, on the basis of a first condition for starting the first shading processing and a second condition for starting the second shading processing.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus, an adjustment method, and an adjustment program, and more particularly to an image forming apparatus equipped with a plurality of reading devices that read recording media, an adjustment method executed by the image forming apparatus, and an adjustment program that causes a computer to execute the adjustment method. [Background technology]

[0002] An image forming apparatus may include a reading device that optically reads a recording medium. For example, Japanese Patent Application Laid-Open No. 2001-177725 describes an image forming apparatus that performs calibration by having multiple reading devices read test patterns and correcting image formation conditions based on the outputs of the multiple reading devices.

[0003] The image forming apparatus described in Japanese Patent Laid-Open No. 2001-177725 forms an image by reading an image using a reading device. In contrast to this, image forming apparatuses have emerged that have an inspection function that reads an image formed on a recording medium by the image forming apparatus using a reading device and inspects the image formed on the recording medium by the image forming apparatus. To maintain inspection accuracy, a shading process is required to correct the output of the reading device. The image reading process by the reading device is performed consecutively with the image forming process by the image forming apparatus. Therefore, while the shading process is being performed on the reading device, the image forming apparatus cannot form an image, resulting in a problem of reduced productivity. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-177725 Summary of the Invention [Problem to be solved by the invention]

[0005] SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus that suppresses a decrease in productivity.

[0006] Another object of the present invention is to provide an adjustment method that suppresses a decrease in productivity of an image forming apparatus.

[0007] It is still another object of the present invention to provide an adjustment program that suppresses a decrease in productivity of an image forming apparatus. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, according to one aspect of the present invention, an image forming apparatus includes a first reading unit, a second reading unit different from the first reading unit, a first adjustment unit that performs a first adjustment process to adjust an output value of the first reading unit based on an output value of the first reading unit, a second adjustment unit that performs a second adjustment process to adjust an output value of the second reading unit based on an output value of the second reading unit, and a determination unit that determines the timing at which the first adjustment process and the second adjustment process are each performed based on a first condition under which the first adjustment process is started and a second condition under which the second adjustment process is started.

[0009] According to another aspect of the present invention, an adjustment method is an adjustment method executed by an image forming device, the image forming device having a first reading unit and a second reading unit different from the first reading unit, and causing the image forming device to execute a first adjustment step of executing a first adjustment process of adjusting an output value of the first reading unit based on an output value of the first reading unit, a second adjustment step of executing a second adjustment process of adjusting an output value of the second reading unit based on an output value of the second reading unit, and a determination step of determining the timing of executing each of the first adjustment process and the second adjustment process based on a first condition under which the first adjustment process is started and a second condition under which the second adjustment process is started.

[0010] According to yet another aspect of the present invention, the adjustment program is an adjustment program executed by a computer that controls an image forming apparatus, the image forming apparatus having a first reading unit and a second reading unit different from the first reading unit, and causes the computer to execute a first adjustment step of executing a first adjustment process of adjusting an output value of the first reading unit based on an output value of the first reading unit, a second adjustment step of executing a second adjustment process of adjusting an output value of the second reading unit based on an output value of the second reading unit, and a determination step of determining the timing of executing each of the first adjustment process and the second adjustment process based on a first condition under which the first adjustment process is started and a second condition under which the second adjustment process is started. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a front view showing an example of an image forming apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram schematically illustrating an example of the internal structure of a paper feed unit. [Figure 3] FIG. 2 is a diagram illustrating an example of an internal configuration of a type inspection unit. [Figure 4] FIG. 2 is a diagram illustrating an example of an internal configuration of an image forming unit. [Figure 5] FIG. 2 is a diagram illustrating an example of an internal configuration of an intermediate paper ejection unit. [Figure 6] FIG. 2 is a diagram schematically illustrating an example of the internal configuration of an image inspection unit. [Figure 7] FIG. 2 is a diagram schematically illustrating an example of the internal configuration of a post-processing unit. [Figure 8] FIG. 2 is a block diagram showing an example of a hardware configuration of the image forming apparatus. [Figure 9] 2 is a block diagram showing an example of functions of a CPU included in the image forming apparatus according to the present embodiment. FIG. [Figure 10] 10 is a flowchart illustrating an example of the flow of an adjustment process. [Figure 11] 10 is a flowchart showing an example of the flow of an adjustment process in a first modified example. [Figure 12]10 is a flowchart showing an example of the flow of an adjustment process in a second modified example. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same components are designated by the same reference numerals. The names and functions of these components are also the same. Therefore, detailed description thereof will not be repeated.

[0013] FIG. 1 is a front view showing an example of an image forming apparatus according to an embodiment of the present invention. Referring to FIG. 1, image forming apparatus 1 includes a paper feed unit 11, a type inspection unit 12, an image forming unit 13, an intermediate paper discharge unit 14, an image inspection unit 15, and a post-processing unit 16. Paper feed unit 11, type inspection unit 12, image forming unit 13, intermediate paper discharge unit 14, image inspection unit 15, and post-processing unit 16 are arranged in this order along a conveyance path. Recording media housed in paper feed unit 11 are conveyed along the conveyance path to post-processing unit 16. Recording media are media on which an image can be formed with toner, and include paper sheets such as paper and overhead projector (OHP) sheets. In this embodiment, a case where paper is used as an example of a recording medium will be described.

[0014] FIG. 2 is a diagram schematically illustrating an example of the internal structure of the paper feed unit. Referring to FIG. 2, paper feed unit 11 includes a first paper feed tray 41, a second paper feed tray 42, and a third paper feed tray 43. Each of first paper feed tray 41, second paper feed tray 42, and third paper feed tray 43 can accommodate multiple sheets of paper. The types, sizes, and orientations of the sheets accommodated in each of first paper feed tray 41, second paper feed tray 42, and third paper feed tray 43 may be the same or different. Paper feed unit 11 removes one sheet at a time from either first paper feed tray 41, second paper feed tray 42, or third paper feed tray 43 and supplies the sheet to type inspection unit 12. Each of first paper feed tray 41, second paper feed tray 42, and third paper feed tray 43 is equipped with a pickup roller and a separation roller, which removes one sheet at a time from the topmost sheet of a stack of multiple sheets. The paper sheets picked up by the pickup roller and the separation roller are transported by the supply rollers 44. The supply rollers 44 transport the paper sheets along a transport path P1. The transport path P1 is a path leading to the type inspection unit 12. The paper sheets transported by the supply rollers 44 proceed along the transport path P1 and are supplied to the type inspection unit 12.

[0015] 3 is a diagram schematically illustrating an example of the internal configuration of the type inspection unit. Referring to FIG. 3, the type inspection unit 12 includes a first reading unit 45, a first conveyance roller 46, and a first discharge roller 47. The first conveyance roller 46 receives the paper supplied from the paper supply unit 11 and conveys the paper along a conveyance path P1. The first discharge roller 47 receives the paper conveyed by the first conveyance roller 46 and conveys the paper. The paper conveyed by the first discharge roller 47 is conveyed along the conveyance path P1 and supplied to the image forming unit 13.

[0016] The first reading unit 45 is disposed between the first conveying roller 46 and the first discharging roller 47. The first reading unit 45 is an optical sensor having a detection area within the conveying path P1.

[0017] The first reading unit 45 is disposed between the first conveyance roller 46 and the first discharge roller 47. The first reading unit 45 includes a first CIS 45a and a second CIS 45b disposed on opposite sides of the conveyance path P1. The first CIS 45a and the second CIS 45b are contact image sensors with identical performance. The first CIS 45a and the second CIS 45b each include a light source extending in a main scanning direction intersecting the paper conveyance direction and multiple photoelectric conversion elements arranged on their reading surfaces aligned in the main scanning direction. The first CIS 45a and the second CIS 45b are disposed with their reading surfaces facing the conveyance path P1. Therefore, while the paper passes between the first CIS 45a and the second CIS 45b, the first CIS 45a and the second CIS 45b read the top and bottom surfaces of the paper, respectively. The output values ​​of the first CIS 45a and the second CIS 45b indicate the light reflectance. Reflectance indicates the ratio of the amount of light received by a photoelectric conversion element to the amount of light output by a light source. Light reflectance varies depending on the condition of the paper surface, and there is a specific relationship between light reflectance and the color of the paper surface. The whiter the paper surface, the greater the light reflectance. Therefore, by determining the relationship between the whiteness of the paper and light reflectance through experiments, etc., the whiteness of the paper can be determined from the light reflectance. Light reflectance also varies depending on the paper basis weight, and there is a specific relationship between the light reflectance and the paper basis weight. Therefore, by determining the relationship between the paper basis weight and light reflectance through experiments, etc., the paper basis weight can be determined from the light reflectance.

[0018] The first reading unit 45 may include a transmissive sensor. A transmissive optical sensor includes a light-emitting unit and a light-receiving unit, and the light-emitting unit and the light-receiving unit are arranged so that they face each other across the transport path P1. The first reading unit 45 detects paper in the area within the transport path P1 between the light-emitting unit and the light-receiving unit. The first reading unit 45 outputs a value indicating light transmittance. The transmittance indicates the ratio of the amount of light received by the light-receiving unit to the amount of light output by the light-emitting unit. The light transmittance varies depending on the basis weight of the paper, and there is a predetermined relationship between the light transmittance and the basis weight of the paper. The greater the basis weight of the paper, the smaller the light transmittance. Therefore, by determining the relationship between the basis weight of the paper and the light transmittance through experiments, etc., the basis weight of the paper can be determined from the light transmittance.

[0019] The first reading unit 45 may also include an ultrasonic sensor. The ultrasonic sensor includes an ultrasonic transmitter and an ultrasonic receiver and is a transmission type. The ultrasonic sensor is arranged so that the ultrasonic transmitter and ultrasonic receiver face each other across the conveying path P1. The ultrasonic transmitter includes a piezoelectric element and a drive circuit for the piezoelectric element, and emits ultrasonic waves. The ultrasonic receiver includes a piezoelectric element and a detection circuit for detecting electromotive force generated in the piezoelectric element, and detects the electromotive force generated in the piezoelectric element by the ultrasonic waves transmitted from the ultrasonic transmitter. The area within the conveying path P1 between the ultrasonic transmitter and the ultrasonic receiver is the detection area.

[0020] The ultrasonic sensor outputs a value indicating the attenuation of ultrasonic waves. Here, the value indicating the attenuation of ultrasonic waves is referred to as the attenuation rate. The attenuation rate of ultrasonic waves differs significantly between stacked paper, which is made up of multiple sheets of paper, and unstuck paper. This is because stacked paper consists of two sheets of paper overlapping each other. When two sheets of paper overlap, a gap exists between the two sheets, so the attenuation rate of ultrasonic waves due to the stacked paper is significantly smaller than the attenuation rate of ultrasonic waves due to a single sheet of paper. Therefore, the presence or absence of overlapping two sheets of paper can be detected from the ultrasonic attenuation rate. The attenuation rate also indicates the ratio of the volume of ultrasonic waves transmitted through the object being conveyed to the volume of ultrasonic waves emitted. The attenuation rate of ultrasonic waves varies depending on the basis weight of the paper, and there is a predetermined relationship between the attenuation rate of ultrasonic waves and the basis weight of the paper. The greater the basis weight of the paper, the smaller the attenuation rate of ultrasonic waves. Therefore, the basis weight of the paper may be determined from the ultrasonic attenuation rate by experimentally determining the relationship between the basis weight of the paper and the attenuation rate of ultrasonic waves.

[0021] FIG. 4 is a schematic diagram illustrating an example of the internal configuration of the image forming unit. Referring to FIG. 4, the image forming unit 13 includes image forming units 20Y, 20M, 20C, and 20K, which correspond to yellow, magenta, cyan, and black, respectively. Here, "Y," "M," "C," and "K" represent yellow, magenta, cyan, and black, respectively. Printing data for yellow, magenta, cyan, and black is input to the image forming units 20Y, 20M, 20C, and 20K, respectively. Since the image forming units 20Y, 20M, 20C, and 20K differ only in the color of the toner they use, we will explain the image forming unit 20Y for forming a yellow image. Hereinafter, for the sake of explanation, the horizontal direction perpendicular to the paper transport direction is referred to as the front-to-rear direction. The direction from the back to the front is referred to as the front, and the direction from the front to the back is referred to as the rear.

[0022] The image forming unit 20Y includes a developing device 21Y, a photosensitive drum 22Y which is an image carrier, a charging roller 23Y, an exposure device 24Y, a primary transfer roller 26Y, a toner bottle 27Y, and a toner hopper 28Y.

[0023] Toner bottle 27Y, toner hopper 28Y, and developing unit 21Y are arranged in this order on a path along which toner is transported. Toner hopper 28Y is arranged immediately before developing unit 21Y. Toner is supplied from toner hopper 28Y to developing unit 21Y via the toner transport path.

[0024] The developing unit 21Y includes a developing roller 25Y, which has a built-in magnet roller and holds the charged toner stored in the developing unit 21Y by magnetic force. The photosensitive drum 22Y has a cylindrical shape, and around the photosensitive drum 22Y, a charging roller 23Y, an exposure device 24Y, a developing roller 25Y, and a primary transfer roller 26Y are arranged in this order along the rotation direction of the photosensitive drum 22Y.

[0025] After the surface of the photosensitive drum 22Y is charged by the charging roller 23Y, it is irradiated with laser light emitted by the exposure device 24Y. The exposure device 24Y exposes an image-corresponding portion of the surface of the photosensitive drum 22Y to light, forming an electrostatic latent image. This forms an electrostatic latent image on the photosensitive drum 22Y. Next, the developing device 21Y develops the electrostatic latent image formed on the photosensitive drum 22Y with toner. Specifically, toner held by the developing roller 25Y is placed on the electrostatic latent image formed on the photosensitive drum 22Y by the action of electric field force, thereby forming a toner image on the photosensitive drum 22Y. The toner image formed on the photosensitive drum 22Y is transferred onto the intermediate transfer belt 29, which is an image carrier, by the action of electric field force using the primary transfer roller 26Y.

[0026] The intermediate transfer belt 29 is suspended by a drive roller R1 and a driven roller R2 so as not to slacken. When the drive roller R1 rotates clockwise in FIG. 1, the intermediate transfer belt 29 rotates clockwise in the drawing at a predetermined speed. As the intermediate transfer belt 29 rotates, the driven roller R2 also rotates clockwise.

[0027] As a result, the image forming units 20Y, 20M, 20C, and 20K transfer toner images onto the intermediate transfer belt 29 in this order. The timing at which each of the image forming units 20Y, 20M, 20C, and 20K transfers a toner image onto the intermediate transfer belt 29 is adjusted by detecting a reference mark on the intermediate transfer belt 29. As a result, yellow, magenta, cyan, black, and white toner images are superimposed on the intermediate transfer belt 29.

[0028] A receiving roller R5, a secondary transfer roller R3, a pair of fixing rollers R4, and a discharge roller R6 are arranged in this order in the conveying direction along the conveying path P1. The receiving roller R5 receives the paper conveyed from the type inspection unit 12 and conveys the paper toward the secondary transfer roller R3.

[0029] The secondary transfer roller R3 is disposed opposite the driven roller R2. An electric field force is generated between the secondary transfer roller R3 and the driven roller R2 by the secondary transfer roller R3. As a result, when a sheet of paper transported along the transport path P1 passes between the secondary transfer roller R3 and the driven roller R2, the toner image formed on the intermediate transfer belt 29 is transferred to the first side of the sheet of paper by the action of the electric field force. The sheet of paper onto which the toner image has been transferred is transported to the pair of fixing rollers R4. The pair of fixing rollers R4 heats and pressurizes the sheet of paper passing between them. This melts the toner and fixes it to the first side of the sheet of paper.

[0030] A first switching claw 33 is disposed on the transport path P1 between the pair of fixing rollers R4 and the discharge rollers R6. The image forming unit 13 includes a reversing device 30 below the transport path P1. The reversing device 30 includes a reversing path P2, a reversing roller R7 disposed on the reversing path P2, and an evacuation tray 34. The first switching claw 33 switches the paper's traveling direction to either the transport path P1 or the reversing path P2. When the first switching claw 33 switches the paper's traveling direction to the transport path P1, the paper transported by the pair of fixing rollers R4 travels along the transport path P1 and is received by the discharge rollers R6. The discharge rollers R6 receive the paper transported by the pair of fixing rollers R4 and transport the paper. The paper transported by the discharge rollers R6 travels along the transport path P1 and is supplied to the intermediate paper discharge unit 14.

[0031] When the first switching claw 33 switches the paper travel direction to the reverse path P2, the paper transported by the fixing roller pair R4 travels along the reverse path P2. The reverse path P2 includes an evacuation path 31 and a resupply path 32. The evacuation path 31 is a path that leads from a position upstream of the first switching claw 33 on the transport path P1 to the evacuation tray 34. The resupply path 32 is a path that leads from the evacuation tray 34 to a position upstream of the receiving roller R5 on the transport path P1.

[0032] When first switching claw 33 switches the paper travel direction to reverse path P2, the paper transported by fixing roller pair R4 enters retreat path 31. A plurality of rollers are arranged on retreat path 31, and the plurality of rollers transport the paper. The paper transported by the plurality of rollers on retreat path 31 proceeds along retreat path 31 and is received by reverse roller R7.

[0033] The reversing roller R7 rotates in a forward direction to transport the paper toward the evacuation tray 34. After transporting a predetermined amount of paper to the evacuation tray 34, the reversing roller R7 reverses its rotation direction and rotates in the opposite direction. When the reversing roller R7 rotates in the opposite direction, the paper, part of which is stored in the evacuation tray 34, is transported in the opposite direction to the direction in which it was transported up to that point, and enters the resupply path 32. The resupply path 32 has multiple rollers arranged therein, and the multiple rollers transport the paper. The paper transported by the multiple rollers is transported along the resupply path 3232 and enters the transport path P1.

[0034] Receiving roller R5 receives the paper sheet transported along resupply path 32 by the multiple rollers of resupply path 32, and transports the paper sheet toward secondary transfer roller R3. The upward-facing side of the paper sheet received by receiving roller R5 through resupply path 32 is the second side opposite to the first side that faces upward while the paper sheet is supplied from type inspection unit 12 and transported along transport path P1. Therefore, an image is formed on the second side of the paper sheet transported along resupply path 32 while it is transported along transport path P1 by receiving roller R5.

[0035] When forming a full-color image, the image forming section 13 drives all of the image forming units 20Y, 20M, 20C, and 20K, but when forming a monochrome image, it drives any one of the image forming units 20Y, 20M, 20C, and 20K. An image can also be formed by combining two or more of the image forming units 20Y, 20M, 20C, and 20K.

[0036] 5 is a diagram showing an example of the internal configuration of the intermediate paper discharge unit. Referring to FIG. 5, the intermediate paper discharge unit 14 includes an intermediate purge tray 61, a second switching claw 63, a first receiving roller 64, a first paper discharge roller 65, and a first purge roller 67. The first receiving roller 64 and the first paper discharge roller 65 are arranged in this order on the conveyance path P1 in the paper conveyance direction. The first receiving roller 64 receives the paper conveyed from the image forming unit 13 and conveys the paper toward the first paper discharge roller 65.

[0037] A second switching claw 63 is disposed on the conveying path P1 between the first receiving roller 64 and the first paper discharge roller 65. In the intermediate paper discharge unit 14, an intermediate purge path P3 that branches off from the conveying path P1 is formed above the conveying path P1. The second switching claw 63 switches the traveling direction of the paper to either the conveying path P1 or the intermediate purge path P3.

[0038] When the second switching claw 63 switches the paper travel direction to the transport path P1, the paper transported by the first receiving rollers 64 travels along the transport path P1. The first paper ejection rollers 65 accept the paper transported by the first receiving rollers 64 and transport the paper. The paper transported by the first paper ejection rollers 65 travels along the transport path P1 and is supplied to the image inspection unit 15.

[0039] When the second switching claw 63 switches the paper travel direction to the intermediate purge path P3, the paper transported by the first receiving roller 64 travels along the intermediate purge path P3. The intermediate purge path P3 is a path that extends from the branch point upstream of the second switching claw 63 on the transport path P1 to the intermediate purge tray 61.

[0040] When the second switching claw 63 switches the paper travel direction to the intermediate purge path P3, the paper transported by the first receiving roller 64 enters the intermediate purge path P3 and is received by the first purge roller 67. The paper transported by the first purge roller 67 proceeds along the intermediate purge path P3 and is discharged to the intermediate purge tray 61.

[0041] 6 is a diagram schematically illustrating an example of the internal configuration of the image inspection unit. Referring to FIG. 6, image inspection unit 15 includes a second reading unit, a first conveyance roller 52, and a second conveyance roller 53. First conveyance roller 52 receives the paper sheet discharged from intermediate paper discharge unit 14 and conveys the paper sheet along conveyance path P1. Second conveyance roller 53 receives the paper sheet conveyed by first conveyance roller 52 and conveys the paper sheet. The paper sheet conveyed by second conveyance roller 53 is conveyed along conveyance path P1 and supplied to post-processing unit 16.

[0042] A second reading unit is disposed between the second conveyance rollers 53. The second reading unit includes a third CIS 51a and a fourth CIS 51b, which are disposed on opposite sides of the conveyance path P1. The third CIS 51a and the fourth CIS 51b are contact image sensors with identical performance. Each of the third CIS 51a and 51b includes a light source extending in a main scanning direction intersecting the paper conveyance direction and multiple photoelectric conversion elements arranged on the reading surface in a line in the main scanning direction. The third CIS 51a and the fourth CIS 51b are disposed with their respective reading surfaces facing the conveyance path P1. Therefore, while the paper passes between the third CIS 51a and the fourth CIS 51b, the third CIS 51a and the fourth CIS 51b read the top and bottom surfaces of the paper, respectively. The third CIS 51a and the fourth CIS 51b have higher performance than the first CIS 45a and the second CIS 45b.

[0043] 7 is a diagram schematically illustrating an example of the internal configuration of the post-processing unit. Referring to FIG. 7, the post-processing unit 16 includes a paper discharge tray 71, a purge tray 72, a third switching claw 73, a second receiving roller 74, a second purge roller 75, and a second paper discharge roller 76. The second receiving roller 74 and the second paper discharge roller 76 are arranged in this order on the conveyance path P1 in the paper conveyance direction. The second receiving roller 74 receives the paper conveyed from the image inspection unit 15 and conveys it toward the second paper discharge roller 76.

[0044] A third switching claw 73 is disposed on the conveying path P1 between the second receiving roller 74 and the second paper discharge roller 76. In the post-processing section 16, a purge path P4 is formed above the conveying path P1, branching off from the conveying path P1. The third switching claw 73 switches the traveling direction of the paper to either the conveying path P1 or the purge path P4.

[0045] When the third switching claw 73 switches the paper travel direction to the transport path P1, the paper transported by the second receiving rollers 74 travels along the transport path P1. The second paper discharge rollers 76 receive the paper transported by the second receiving rollers 74 and transport the paper. The paper transported by the second paper discharge rollers 76 travels along the transport path P1 and is discharged onto the paper discharge tray 71.

[0046] When the third switching claw 73 switches the paper travel direction to the purge path P4, the paper transported by the second receiving roller 74 travels along the purge path P4. The purge path P4 is a path that extends from the branch point upstream of the third switching claw 73 on the transport path P1 to the purge tray 72.

[0047] When the third switching claw 73 switches the paper travel direction to purge path P4, the paper transported by the second receiving roller 74 enters purge path P4 and is received by the second purge roller 75. The paper transported by the second purge roller 75 proceeds along purge path P4 and is discharged to the purge tray 72.

[0048] Although not shown in the figure, post-processing unit 16 includes a mechanism for performing post-processing on sheets. The mechanism for performing post-processing includes processes for processing sheets. The processes for processing sheets include a punching process for forming punch holes, a stapling process for driving staples into a stack of multiple sheets, and a bending process for folding sheets.

[0049] Fig. 8 is a block diagram showing an example of the hardware configuration of an image forming apparatus. Referring to Fig. 8, image forming apparatus 1 includes a main circuit 110. Main circuit 110 is provided in any of paper feed unit 11, type inspection unit 12, image forming unit 13, intermediate paper discharge unit 14, image inspection unit 15, and post-processing unit 16. Here, an example will be described in which main circuit 110 is provided in image forming unit 13. Note that main circuit 110 may be provided in a housing separate from paper feed unit 11, type inspection unit 12, image forming unit 13, intermediate paper discharge unit 14, image inspection unit 15, and post-processing unit 16.

[0050] The main circuit 110 includes a CPU (Central Processing Unit) 111 that controls the entire image forming apparatus 1, a communication interface (I / F) unit 112, a ROM (Read Only Memory) 113, a RAM (Random Access Memory) 114, a hard disk drive (HDD) 115 as a large-capacity storage device, and an external storage device 118. The CPU 111 is connected to the paper feed unit 11, the type inspection unit 12, the image forming unit 13, the intermediate paper discharge unit 14, the image inspection unit 15, the post-processing unit 16, and the operation panel 18, and controls the entire image forming apparatus 1.

[0051] ROM 113 stores programs executed by CPU 111 or data required to execute the programs. RAM 114 is used as a work area when CPU 111 executes the programs. RAM 114 also temporarily stores image data continuously sent from document reading unit 130.

[0052] The communication I / F unit 112 is an interface for connecting the image forming apparatus 1 to a network. The communication I / F unit 112 communicates with other computers or data processing devices connected to the network using a communication protocol such as TCP (Transmission Control Protocol) or FTP (File Transfer Protocol). The network to which the communication I / F unit 112 is connected is a local area network (LAN), and the connection type may be either wired or wireless. Furthermore, the network is not limited to a LAN, and may be a wide area network (WAN), a public switched telephone network (PSTN), the Internet, or the like.

[0053] External storage device 118 is controlled by CPU 111, and is equipped with a CD-ROM (Compact Disk Read Only Memory) 119 or a semiconductor memory. In this embodiment, an example will be described in which CPU 111 executes a program stored in ROM 113. CPU 111 may control external storage device 118 to read a program to be executed by CPU 111 from CD-ROM 119, store the read program in RAM 114, and execute it.

[0054] The recording medium for storing the programs executed by CPU 111 is not limited to CD-ROM 119, but may be a flexible disk, cassette tape, optical disk, semiconductor memory, or other medium. Optical disks include magnetic optical discs (MOs), mini discs (MDs), and digital versatile discs (DVDs). Semiconductor memories include IC cards, optical cards, mask ROMs, and erasable programmable ROMs (EPROMs). CPU 111 may also load a program stored in HDD 115 into RAM 114 and execute it. Programs stored in HDD 115 include programs downloaded from a computer connected to the network and stored in HDD 115. Programs stored in HDD 115 also include programs written to HDD 115 by a computer connected to the network. The term "program" as used herein refers not only to programs directly executable by CPU 111 but also to source programs, compressed programs, encrypted programs, and the like.

[0055] Operation panel 18 is provided on the top of the housing of image forming unit 13. Operation panel 18 includes display unit 19a and operation unit 19b. Display unit 19a is, for example, a liquid crystal display (LCD) that displays an instruction menu for the user, information about acquired image data, etc. Note that instead of an LCD, any device that displays images, such as an organic EL (electroluminescence) display, can be used.

[0056] The operation unit 19b includes a touch panel or hard keys. The touch panel detects a position on the display surface of the display unit 19a designated by a user. The hard keys are, for example, contact switches.

[0057] Fig. 9 is a block diagram showing an example of functions of a CPU included in the image forming apparatus 1 according to the present embodiment. The functions shown in Fig. 9 are realized by CPU 111 included in image forming apparatus 1 as CPU 111 executes an adjustment program stored in ROM 113, HDD 115, or CD-ROM 119. Referring to Fig. 9, CPU 111 includes first sensor control unit 121, first adjustment unit 123, determination unit 125, second sensor control unit 127, second adjustment unit 129, and job execution unit 131.

[0058] By executing a print job, the job execution unit 131 controls the paper feed unit 11, type inspection unit 12, image forming unit 13, intermediate paper discharge unit 14, image inspection unit 15, and post-processing unit 16, and causes the image forming device 1 to form an image on a recording medium. When the image forming device 1 forms images on multiple sheets of paper, the paper feed unit 11 continuously supplies the sheets of paper at predetermined intervals. The sheets of paper supplied from the paper feed unit 11 are transported from the type inspection unit 12 to the post-processing unit 16. Therefore, multiple sheets of paper exist between the paper feed unit 11 and the post-processing unit 16.

[0059] The job execution unit 131 controls the paper feed unit 11, selects one of the three paper feed trays 151, 152, and 153 in accordance with the printing conditions, and transports the paper stored in the selected one as the object to be transported.

[0060] The first sensor control unit 121 controls the first reading unit 45 to acquire information about the physical properties of the paper. The information about the physical properties includes basis weight, thickness, hardness, moisture content, and surface condition. The first sensor control unit 121 determines the type of paper based on the information about the physical properties of the paper. For example, the relationship between light reflectance and basis weight is determined in advance by experiment or simulation, and the determined relationship is maintained. The first sensor control unit 121 determines the basis weight from the light reflectance based on this relationship. The first sensor control unit 121 determines the type of paper from the determined basis weight by referring to a table that defines the relationship between paper type and basis weight. Paper types include paper and envelopes. Paper also includes plain paper, high-quality paper, recycled paper, and photo paper.

[0061] Furthermore, if the first reading unit 45 is equipped with a transmission-type photoelectric sensor, the first sensor control unit 121 may determine the basis weight from the light transmittance. The relationship between the light transmittance and the basis weight is determined in advance by experiment or simulation, and the determined relationship is maintained. The first sensor control unit 121 determines the basis weight from the light transmittance based on this relationship. Furthermore, if the first reading unit 45 is equipped with an ultrasonic sensor, the basis weight of the paper may be determined from the attenuation rate of ultrasonic waves. The relationship between the attenuation rate of ultrasonic waves and the basis weight is determined in advance by experiment or simulation, and the determined relationship is maintained. The first sensor control unit 121 determines the basis weight from the attenuation rate of ultrasonic waves based on this relationship.

[0062] The first sensor control unit 121 determines whether the paper type is normal or not in response to detecting the paper type. The second sensor control unit 127 determines whether the paper type matches the type defined in the print job. If the paper type matches the type defined in the print job, the second sensor control unit 127 outputs information indicating the type to the job execution unit 131. If the paper type does not match the type defined in the print job, the first sensor control unit 121 outputs a type abnormality signal indicating that the type is abnormal to the job execution unit 131.

[0063] The second sensor control unit 127 controls the image inspection unit 15 to inspect the image formed on the paper. The second sensor control unit 127 acquires first inspection data output by the third CIS 51a of the image inspection unit 15 after reading the paper and second inspection data output by the fourth CIS 51b after reading the paper. The second sensor control unit 127 determines whether the image is normal based on the first inspection data and the second inspection data. For example, the second sensor control unit 127 compares the first inspection data and the second inspection data with data included in the print job. If the difference between either the first inspection data or the second inspection data and the data included in the print job is smaller than a predetermined threshold, the second sensor control unit 127 outputs an image normal signal to the job execution unit 131 indicating that the image is normal. If the difference between either the first inspection data or the second inspection data and the data included in the print job is equal to or greater than the threshold, the second sensor control unit 127 outputs an image abnormality signal to the job execution unit 131 indicating that the image is abnormal.

[0064] In response to receiving the type abnormality signal from the first sensor control unit 121, the job execution unit 131 halts execution of the print job. The job execution unit 131 controls the paper feed unit 11 to halt paper feed, and controls the intermediate paper discharge unit 14 to purge the paper before image formation. The paper to be purged is paper that has already been supplied from the paper feed unit 11 and has not yet had an image formed on it by the image forming unit 13 at the stage when the type abnormality signal is received from the first sensor control unit 121. The job execution unit 131 controls the image forming unit 13 to transport the paper to the intermediate paper discharge unit 14 without forming an image on the paper to be purged. The job execution unit 131 also controls the intermediate paper discharge unit 14 to switch the second switching claw 63 to the intermediate purge path P3, and discharge the paper to be purged to the intermediate purge tray 61.

[0065] In response to an image abnormality signal being input from the second sensor control unit 127, the job execution unit 131 purges the sheet on which the image abnormality has been detected. Specifically, the job execution unit 131 controls the post-processing unit 16 to switch the third switching claw 73 to the purge path P4, and discharges the sheet on which the image abnormality has been determined by the second sensor control unit 127 to the discharge tray 71. The job execution unit 131 may also execute recovery processing. The recovery processing is processing for resuming image formation from the page on which the image abnormality has been determined.

[0066] The first adjustment unit 123 executes a first shading process for each of the first CIS 45a and the second CIS 45b to determine a correction value. The first shading process is executed for each of the first CIS 45a and the second CIS 45b to correct for variations in light intensity in the main scanning direction and variations in the sensitivity of the photoelectric conversion elements of each of the first CIS 45a and the second CIS 45b. The first adjustment unit 123 causes each of the first CIS 45a and the second CIS 45b to read a reference surface. The reference surface is a flat surface prepared in advance and has a reference color such as white. The first adjustment unit 123 places a first shading plate having the reference surface between the first CIS 45a and the second CIS 45b and obtains output values ​​output by each of the first CIS 45a and the second CIS 45b after reading the reference surface. The first adjustment unit 123 determines correction values ​​for correcting the output values ​​based on the output values ​​of the first CIS 45a and the second CIS 45b. Note that a first shading plate for the first CIS 45a and a first shading plate for the second CIS 45b may be used. Furthermore, instead of moving the first shading plate, the first adjustment unit 123 may move each of the first CIS 45a and the second CIS 45b.

[0067] The first adjustment unit 123 executes the first shading process at a predetermined time interval. It takes a predetermined time for the first adjustment unit 123 to finish the first shading process after starting it. Hereinafter, the time interval at which the first adjustment unit 123 executes the first shading process will be referred to as the first interval, and the time from when the first adjustment unit 123 starts the first shading process to when it finishes it will be referred to as the first time. The first interval is a value determined by the user of the image forming apparatus 1. The first time is a value determined by the specifications of each of the first CIS 45a and the second CIS 45b. Note that the first time may also be determined by the user. The first interval and the first time are stored in advance in the HDD 115.

[0068] The second adjustment unit 129 performs a second shading process on each of the third CIS 51a and the fourth CIS 51b to determine a correction value. The second shading process is performed on each of the third CIS 51a and the fourth CIS 51b to correct for variations in light intensity in the main scanning direction and variations in the sensitivity of the photoelectric conversion elements of each of the third CIS 51a and the fourth CIS 51b. The first adjustment unit 123 causes each of the third CIS 51a and the fourth CIS 51b to read a reference surface. The reference surface is a flat surface prepared in advance and has a reference color such as white. The first adjustment unit 123 places a second shading plate having a reference surface between the third CIS 51a and the fourth CIS 51b and obtains output values ​​output by each of the third CIS 51a and the fourth CIS 51b after reading the reference surface. The first adjustment unit 123 determines correction values ​​for correcting the output values ​​based on the output values ​​of the third CIS 51a and the fourth CIS 51b. Note that a second shading plate for the third CIS 51a and a second shading plate for the fourth CIS 51b may be used. Furthermore, the second adjustment unit 129 may move each of the third CIS 51a and the fourth CIS 51b instead of moving the second shading plate.

[0069] The second adjustment unit 129 executes the second shading process at a predetermined time interval. It takes a predetermined time for the second adjustment unit 129 to finish the second shading process after it starts. Hereinafter, the time interval at which the second adjustment unit 129 executes the second shading process is referred to as the second interval, and the time from when the second adjustment unit 129 starts the second shading process to when it finishes is referred to as the second time. The second interval is a value determined by the user of the image forming apparatus 1. The second time is a value determined by the specifications of each of the third CIS 51a and the fourth CIS 51b. The second time may also be determined by the user. The second interval and the second time are stored in advance in the HDD 115.

[0070] The determination unit 125 determines the timings at which the first shading process and the second shading process are executed based on a first condition and a second condition. The first condition is a condition under which the first shading process is started. The second condition is a condition under which the second shading process is started. The first condition includes a first interval. The second condition includes a second interval.

[0071] The determining unit 125 changes one of the first interval and the second interval based on the other so that one of the first interval and the second interval becomes an integer multiple of the other, or vice versa.

[0072] When the first interval is longer than the second interval, the determination unit 125 changes the second interval so that the first interval becomes an integer multiple of the second interval. When the first interval is changed, the first difference between before and after the change of the first interval may be smaller than the second difference between before and after the change of the second interval. In this case, the second interval is changed while maintaining the first interval at which the first shading process is executed at the value set by the user.

[0073] If the first interval is longer than the second interval, the determination unit 125 may change the first interval so that the first interval becomes an integer multiple of the second interval. If the second interval is shorter than the first interval, the determination unit 125 changes the first interval while maintaining the second interval, at a value set by the user, at which the second shading process is executed.

[0074] Furthermore, when the first time is longer than the second time, the determination unit 125 determines the timing at which the second shading process is executed so that the second shading process is executed while the first shading process is being executed. When the second time is longer than the first time, the determination unit 125 determines the timing at which the first shading process is executed so that the first shading process is executed while the second shading process is being executed.

[0075] The determination unit 125 outputs a first adjustment instruction to the first adjustment unit 123 at the timing when the first shading processing is to be executed. The first adjustment unit 123 executes the first shading processing in response to the first adjustment instruction being input from the determination unit 125. The determination unit 125 outputs a second adjustment instruction to the second adjustment unit 129 at the timing when the second shading processing is to be executed. The second adjustment unit 129 executes the second shading processing in response to the second adjustment instruction being input from the determination unit 125.

[0076] 10 is a flowchart showing an example of the flow of the adjustment process. The adjustment process is performed by CPU 111 included in image forming apparatus 1 as CPU 111 executes an adjustment program stored in ROM 113, HDD 115, or CD-ROM 119. Referring to FIG. 10, CPU 111 acquires a first interval (step S01) and proceeds to step S02. The first interval set by the user is stored in HDD 115. CPU 111 reads the first interval from HDD 115.

[0077] In step S02, CPU 111 acquires the second interval and proceeds to step S03. The second interval set by the user is stored in HDD 115. CPU 111 reads the second interval from HDD 115.

[0078] In step S03, the first interval and the second interval are compared. If the first interval is greater than the second interval, CPU 111 proceeds to step S04; otherwise, CPU 111 proceeds to step S05.

[0079] In step S04, the second interval is changed and the process ends. The second interval is changed so that the first interval becomes an integer multiple of the second interval. In step S05, the first interval is changed and the process ends. The first interval is changed so that the second interval becomes an integer multiple of the first interval.

[0080] This allows the second shading process to be executed while the first shading process is being executed, thereby making it possible to shorten the time during which at least one of the first shading process and the second shading process is executed as much as possible.

[0081] <First Modification> The image forming apparatus 1 in the above embodiment determines the timings at which the first shading process and the second shading process are performed based on the first interval and the second interval. In contrast, the image forming apparatus 1 in the first modified example determines the timings at which the first shading process and the second shading process are performed based on the first time and the second time.

[0082] In a first modified example, the first condition includes a first time, and the second condition includes a second time. The determination unit 125 changes one of the first interval and the second interval based on the other. The determination unit 125 determines the other of the first interval and the second interval to be changed based on the first time and the second time. Specifically, if the first time is longer than the second time, the determination unit 125 changes the first interval based on the second interval. If the first interval is longer than the second interval, the determination unit 125 changes the first interval so that the first interval becomes an integer multiple of the second interval. If the second interval is longer than the first interval, the determination unit 125 changes the first interval so that the second interval becomes an integer multiple of the first interval.

[0083] If the second time is longer than the first time, the determination unit 125 changes the second interval based on the first interval. If the first interval is longer than the second interval, the determination unit 125 changes the second interval so that the first interval becomes an integer multiple of the second interval. If the second interval is longer than the first interval, the determination unit 125 changes the second interval so that the second interval becomes an integer multiple of the first interval.

[0084] This allows the first shading process and the second shading process to be executed in parallel, thereby shortening the time required for at least one of the first shading process and the second shading process to the shortest possible time.

[0085] 11 is a flowchart showing an example of the flow of the adjustment process in the first modified example. Referring to FIG. 11, CPU 111 acquires a first time (step S11) and proceeds to step S12. The first time set by the user is stored in HDD 115. CPU 111 reads out the first time from HDD 115.

[0086] In step S12, the CPU 111 acquires the second time and proceeds to step S13. The second time set by the user is stored in the HDD 115. The CPU 111 reads the second time from the HDD 115.

[0087] In step S13, the first time and the second time are compared. If the first time is longer than the second time, CPU 111 proceeds to step S14, but if not, proceeds to step S15.

[0088] In step S14, the first interval is changed and the process ends. The first interval is changed so that the first interval becomes an integer multiple of the second interval or the second interval becomes an integer multiple of the first interval. In step S15, the second interval is changed and the process ends. The second interval is changed so that the first interval becomes an integer multiple of the second interval or the second interval becomes an integer multiple of the first interval.

[0089] This allows the second shading process to be executed while the first shading process is being executed, thereby making it possible to shorten the time during which at least one of the first shading process and the second shading process is executed as much as possible.

[0090] <Second Modification> The image forming apparatus 1 in the second modified example determines the timings at which the first shading process and the second shading process are performed based on the first time, the second time, the first interval, and the second interval.

[0091] In a second modified example, the first condition includes a first time and a first interval. The second condition includes a second time and a second interval. The determination unit 125 changes one of the first interval and the second interval based on the other. The determination unit 125 determines the other of the first interval and the second interval to be changed based on the first time, the first interval, the second time, and the second interval. Specifically, if the first interval is longer than the second interval and the first time is equal to or shorter than the second time, the determination unit 125 changes the first interval based on the second interval. Specifically, the determination unit 125 changes the first interval so that the first interval is an integer multiple of the second interval.

[0092] If the first interval is equal to or shorter than the second interval and the first time is longer than the second time, the determination unit 125 changes the second interval based on the first interval. Specifically, the determination unit 125 changes the second interval so that the second interval becomes an integer multiple of the first interval.

[0093] The decision unit 125 changes either the first interval or the second interval based on the other when the first interval is longer than the second interval and the first time is longer than the second time, or when the first interval is equal to or shorter than the second interval and the first time is equal to or shorter than the second time.

[0094] This allows the first shading process and the second shading process to be executed in parallel, thereby shortening the time required for at least one of the first shading process and the second shading process to the shortest possible time.

[0095] 12 is a flowchart showing an example of the flow of adjustment processing in the second modified example. Referring to FIG. 12, CPU 111 acquires the first interval and the time (step S21), and proceeds to step S22. The first interval and the first time set by the user are stored in HDD 115. CPU 111 reads out the first interval and the first time from HDD 115.

[0096] In step S22, CPU 111 acquires the second interval and the second time, and proceeds to step S23. The second interval and the second time set by the user are stored in HDD 115. CPU 111 reads the second interval and the second time from HDD 115.

[0097] In step S23, the first interval and the second interval are compared. If the first interval is greater than the second interval, CPU 111 proceeds to step S24; otherwise, CPU 111 proceeds to step S27.

[0098] In step S24, the first time is compared with the second time. If the first time is greater than the second time, CPU 111 proceeds to step S25; otherwise, CPU 111 proceeds to step S26. In step S26, the first interval is changed, and the process ends. The first interval is changed so that the first interval becomes an integer multiple of the second interval. In step S25, one of the first interval and the second interval is changed based on the other, and the process ends.

[0099] In step S27, the first time and the second time are compared. If the first time is greater than the second time, CPU 111 proceeds to step S28; otherwise, CPU 111 proceeds to step S29. In step S28, the second interval is changed, and the process ends. The second interval is changed so that the second interval becomes an integer multiple of the first interval. In step S29, one of the first interval and the second interval is changed based on the other, and the process ends.

[0100] This makes it possible to shorten the time required to perform at least one of the first shading process and the second shading process as much as possible.

[0101] <Third Modification> In the above-described embodiment, the first shading process executed by the first adjustment unit 123 and the second shading process executed by the second sensor control unit 127 have been described as examples of adjustment processes. However, adjustment processes are not limited to these. The adjustment process may be any process that prevents the image forming apparatus 1 from forming an image while it is being executed. For example, the adjustment process may be a calibration process that changes the setting values ​​of the image forming apparatus 1.

[0102] <Summary of implementation form> (Item 1) A first reading unit; a second reading unit different from the first reading unit; a first adjustment unit that executes a first adjustment process to adjust the output value of the first reading unit based on the output value of the first reading unit; a second adjustment unit that executes a second adjustment process to adjust the output value of the second reading unit based on the output value of the second reading unit; and a determination unit that determines the timing at which the first adjustment process and the second adjustment process are executed based on a first condition for starting the first adjustment process and a second condition for starting the second adjustment process.

[0103] According to this aspect, the timings for executing the first adjustment process and the second adjustment process are determined based on the first condition for starting the first adjustment process and the second condition for starting the second adjustment process. Therefore, the first adjustment process and the second adjustment process are executed in parallel, and the period during which either the first adjustment process or the second adjustment process is executed can be shortened as much as possible. As a result, an image forming apparatus can be provided that suppresses a decrease in productivity.

[0104] (Item 2) The first condition and the second condition include a first interval at which the first adjustment process is performed and a second interval at which the second adjustment process is performed, respectively; Item 2. The image forming apparatus according to item 1, wherein the determination unit changes one of the first interval and the second interval based on the other.

[0105] According to this aspect, since one of the first interval and the second interval is changed based on the other, the first adjustment process and the second adjustment process can be executed in parallel.

[0106] (Item 3) The image forming apparatus according to Item 2, wherein the determination unit changes the other so that the one becomes an integer multiple of the other or the other becomes an integer multiple of the one.

[0107] According to this aspect, one is changed so that the other becomes an integer multiple of the other, or vice versa. Therefore, even if the first interval and the second interval are different, it is possible to easily determine the timing at which the first adjustment process and the second adjustment process are executed in parallel.

[0108] (Item 4) The image forming apparatus according to item 2 or 3, wherein the one of the two is longer than the other of the two.

[0109] According to this aspect, when the first interval is longer than the second interval, the second interval is changed, and when the first interval is shorter than the second interval, the first interval is changed. This makes it easy to determine the timing at which the first adjustment process and the second adjustment process are executed in parallel.

[0110] (Item 5) An image forming apparatus as described in Item 2 or 3, wherein the one of the two is the first interval when the first time during which the first adjustment process is executed is longer than the second time during which the second adjustment process is executed, and is the second interval when the first time is shorter than the two hours.

[0111] According to this aspect, if the first time during which the first adjustment process is executed is longer than the second time during which the second adjustment process is executed, the second interval is changed, and if the first time during which the first adjustment process is executed is shorter than the second time during which the second adjustment process is executed, the first interval is changed. Since the process that takes longer to execute is given priority, it is possible to ensure the accuracy of the process.

[0112] (Item 6) The image forming apparatus according to item 5, wherein the determination unit determines the timing at which one of the processes is executed so that the other process is executed while the other process is being executed.

[0113] According to this aspect, the time during which the first adjustment process and the second adjustment process are executed in parallel is lengthened, and therefore the period during which either the first adjustment process or the second adjustment process is executed can be shortened as much as possible.

[0114] (Item 7) An image forming unit that forms an image on a recording medium is further provided, the first reading unit reads a recording medium before an image is formed by the image forming unit; 7. The image forming apparatus according to any one of items 1 to 6, wherein the second reading unit reads a recording medium on which an image has been formed by the image forming unit.

[0115] (Item 8) The image forming apparatus according to any one of items 1 to 6, further comprising a characteristics determining unit that determines information relating to the characteristics of the recording medium based on the output value of the first reading unit.

[0116] (Item 9) An adjustment method executed in an image forming apparatus, The image forming apparatus includes a first reading unit, a second reading unit different from the first reading unit, a first adjustment step of performing a first adjustment process of adjusting the output value of the first reading unit based on the output value of the first reading unit; a second adjustment step of performing a second adjustment process to adjust the output value of the second reading unit based on the output value of the second reading unit; and a determination step of determining the timing at which the first adjustment process and the second adjustment process are to be executed based on a first condition at which the first adjustment process is started and a second condition at which the second adjustment process is started, in the image forming device.

[0117] According to this aspect, it is possible to provide an adjustment method that suppresses a decrease in productivity of an image forming apparatus.

[0118] (Item 10) An adjustment program executed by a computer that controls an image forming apparatus, The image forming apparatus includes a first reading unit, a second reading unit different from the first reading unit, a first adjustment step of performing a first adjustment process of adjusting the output value of the first reading unit based on the output value of the first reading unit; a second adjustment step of performing a second adjustment process to adjust the output value of the second reading unit based on the output value of the second reading unit; and a determination step of determining the timing at which the first adjustment process and the second adjustment process are to be executed, based on a first condition at which the first adjustment process is started and a second condition at which the second adjustment process is started.

[0119] According to this aspect, it is possible to provide an adjustment program that suppresses a decrease in productivity of an image forming apparatus.

[0120] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0121] 1 image forming device, 11 paper feed unit, 12 type inspection unit, 13 image forming unit, 14 intermediate paper discharge unit, 15 image inspection unit, 16 post-processing unit, 18 operation panel, 45 first reading unit, 45a first CIS, 45b second CIS, 51 second reading unit, 51a third CIS, 51b fourth CIS, 111 CPU, 112 communication I / F unit, 113 ROM, 114 RAM, 115 HDD, 118 external storage device, 119 CD-ROM, 121 first sensor control unit, 123 first adjustment unit, 125 determination unit, 127 second sensor control unit, 129 second adjustment unit, 130 document reading unit, 131 job execution unit.

Claims

1. a first reading unit; a second reading unit different from the first reading unit; a first adjustment unit that executes a first adjustment process to adjust the output value of the first reading unit based on the output value of the first reading unit; a second adjustment unit that executes a second adjustment process to adjust the output value of the second reading unit based on the output value of the second reading unit; and a determination unit that determines the timing at which the first adjustment process and the second adjustment process are executed based on a first condition for starting the first adjustment process and a second condition for starting the second adjustment process.

2. the first condition and the second condition include a first interval at which the first adjustment process is performed and a second interval at which the second adjustment process is performed, respectively; The image forming apparatus according to claim 1 , wherein the determination unit changes one of the first interval and the second interval based on the other.

3. The image forming apparatus according to claim 2 , wherein the determining unit changes the other so that the one becomes an integer multiple of the other or the other becomes an integer multiple of the one.

4. 4. The image forming apparatus according to claim 2, wherein the one of the first and second electrodes is longer than the other of the first and second electrodes.

5. 4. An image forming apparatus according to claim 2, wherein the one of the first and second intervals is the first interval when the first time for which the first adjustment process is executed is longer than the second time for which the second adjustment process is executed, and the one of the first and second intervals is the second interval when the first time is shorter than the second time.

6. The image forming apparatus according to claim 5 , wherein the determination unit determines the timing at which one of the processes is executed so that the other process is executed while the other process is being executed.

7. further comprising an image forming unit that forms an image on a recording medium; the first reading unit reads a recording medium before an image is formed by the image forming unit; 4. The image forming apparatus according to claim 1, wherein the second reading section reads a recording medium on which an image has been formed by the image forming section.

8. 4. The image forming apparatus according to claim 1, further comprising a characteristics determining section that determines information relating to characteristics of the recording medium based on the output value of the first reading section.

9. An adjustment method performed in an image forming apparatus, The image forming apparatus includes a first reading unit and a second reading unit different from the first reading unit, a first adjustment step of performing a first adjustment process of adjusting the output value of the first reading unit based on the output value of the first reading unit; a second adjustment step of performing a second adjustment process to adjust the output value of the second reading unit based on the output value of the second reading unit; and a determination step of determining the timing at which the first adjustment process and the second adjustment process are to be executed based on a first condition for starting the first adjustment process and a second condition for starting the second adjustment process, in the image forming device.

10. An adjustment program executed by a computer that controls an image forming apparatus, The image forming apparatus includes a first reading unit and a second reading unit different from the first reading unit, a first adjustment step of performing a first adjustment process of adjusting the output value of the first reading unit based on the output value of the first reading unit; a second adjustment step of performing a second adjustment process to adjust the output value of the second reading unit based on the output value of the second reading unit; and a determination step of determining the timing at which the first adjustment process and the second adjustment process are to be executed based on a first condition at which the first adjustment process is started and a second condition at which the second adjustment process is started.

Images