JP2005010569A - Image density correction quantity setting device, device and system for image formation, and method and program for setting image density correction quantity - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To optionally set a correction quantity for uneven density correction. <P>SOLUTION: Set is the correction quantity which is a physical quantity affecting the density of an image when an image forming device that forms the image by forming an electromagnetic latent image on a cylindrical photoreceptor which rotates in a 2nd direction crossing a 1st direction by exposing the photoreceptor to a light beam moving in the 1st direction, and developing and transferring the electrostatic latent image to a recording medium while the photoreceptor rotates. The correction quantity is set individually corresponding to at least one of a plurality of positions in the 2nd direction between reference-position corresponding positions corresponding to reference positions on the recording medium based upon a predetermined reference position as a reference rotational position of the photoreceptor. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image density correction amount setting device, an image forming apparatus, an image forming system, an image density correction amount setting method, and an image density correction amount setting program. More specifically, the present invention relates to an image density at the time of image formation. An image density correction amount setting device, an image density correction amount setting method, and an image density correction amount setting program for setting a correction amount for an influential physical amount, and correcting the physical amount based on the set correction amount to obtain a corrected physical amount. The present invention relates to an image forming apparatus that forms an image based on the image forming apparatus, an image density correction amount setting device, and an image forming system including the image forming device.
[0002]
[Prior art]
In a copying machine, a laser printer, an electrophotographic copying machine, etc., a light beam scans the surface of the photosensitive member to form a latent image, and the latent image is developed and transferred to a recording medium such as paper. Accordingly, an image forming apparatus that forms an image on a recording medium has become widespread. In such an image forming apparatus, there is a problem that non-uniformity (density unevenness) occurs in the density of the formed image. It is known that this uneven density occurs due to a plurality of factors. For example, the cause of density unevenness that occurs when a latent image is formed on a photoconductor includes uneven charge potential / image potential due to nonuniformity of sensitivity (chargeability / photosensitivity) of the photoconductor, and nonuniform exposure energy distribution. Etc. Also in the development process, unevenness in the amount of toner supplied to the latent image on the photoconductor and nonuniformity in the distance between the developing roll and the photoconductor cause unevenness in the developed toner image. Further, in the process of transferring an image from the photosensitive member to the recording medium via the intermediate transfer member, uneven charging of the transfer device and unevenness of the force (nip force) for holding the recording medium are caused by unevenness of the image on the recording medium. It is a factor. Further, in a tandem image forming apparatus having an independent photosensitive drum for each color, when transferring another color (secondary color) on top of a certain color that has already been transferred to the intermediate transfer member, a transfer roll It is known that if the nip force of the toner is too strong, a retransfer phenomenon in which the toner returns to the photosensitive drum of the secondary color occurs, resulting in density unevenness.
[0003]
Conventionally, various techniques for eliminating density unevenness are known. For example, the final image (test image) is read by a scanner mounted on the image forming apparatus to detect a density distribution in the main scanning direction or the sub-scanning direction, and pixel data based on a correction distribution created based on the density distribution There is provided a method of forming an image by correcting the image (see Patent Document 1).
[0004]
[Patent Document 1]
JP-A-11-112810
[Patent Document 2]
JP-A-6-3911
[Patent Document 3]
JP-A-8-30145
[Patent Document 4]
JP 2000-56522 A
[0005]
[Problems to be solved by the invention]
However, in this density correction method, since the correction amount is automatically calculated based on the detected density distribution, the correction amount cannot be arbitrarily set. Therefore, there is a problem that when the corrected image is visually confirmed and density unevenness still exists, this cannot be solved. Further, since a scanner for reading a test image is required, a large-scale device is required.
[0006]
The present invention has been made in view of the above facts, and is an image density correction amount setting device, an image density correction amount setting method, and an image density correction amount that can arbitrarily set a correction amount for correcting density unevenness. It is an object of the present invention to provide a setting program and an image forming apparatus and an image forming system related thereto.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, an image density correction amount setting device according to the first aspect of the present invention is a cylindrical photosensitive device in which a light beam moving in a first direction rotates in a second direction intersecting the first direction. By exposing the body, an electrostatic latent image is formed on the photoconductor, and the electrostatic latent image is developed and transferred to the recording medium while the photoconductor rotates, whereby an image is formed on the recording medium. An image density correction amount setting device that sets a correction amount of a physical quantity that affects an image density at the time of image formation of an image forming apparatus to be formed, and is a predetermined reference that serves as a reference for the rotational position of a photoconductor Based on the position, at least one of the plurality of positions in the second direction between the two reference position corresponding positions corresponding to the reference position on the recording medium that is continuously determined by the rotation of the photosensitive member with respect to the recording medium. Settings to be set individually according to the position And it includes a stage.
[0008]
That is, the setting means corresponds to a reference position on the recording medium that is continuously determined by the rotation of the photosensitive member with respect to the recording medium based on a predetermined reference position serving as a reference for the rotational position of the photosensitive member. The setting is individually made corresponding to at least one of a plurality of positions in the second direction between the two reference position corresponding positions.
[0009]
Therefore, the correction amount can be arbitrarily set. Here, the physical quantity is an amount that controls the exposure amount of the light beam, and the amount that controls the exposure amount is the drive current of the optical scanning device that emits the light beam.
[0010]
Further, in the case where each of the plurality of positions and the correction amount corresponding to each of the plurality of positions are determined in advance, the setting unit may set the plurality of positions in the second direction of the image as in claim 2. The correction amount is set individually by setting the correction amount at another position instead of at least one position, or at least one position of a plurality of positions in the second direction of the image as in claim 3 The correction amount may be individually set or changed by changing the correction amount corresponding to.
[0011]
Further, as in claim 4, the apparatus further comprises density detecting means for detecting the density at a plurality of predetermined positions in the second direction of the image, and the predetermined correction amount is the density of the image detected by the density detecting means. It may be set by setting means based on this.
[0012]
That is, the setting means predetermines the correction amount based on the image density detected by the density detection means. Here, the length in the first direction of the area on the image where the density is detected by the density detecting means may be shorter than the length in the first direction of the image.
[0013]
According to another aspect of the present invention, the setting unit may set a correction amount for each image forming condition in image formation. Here, the image forming condition is at least one of the color of the material used to form the image, the number of the colors, and the fineness of the image to be formed. Note that the fineness of an image is the size of halftone dots in the area of the image or the resolution of halftone dots.
[0014]
That is, since the setting unit can set the correction amount corresponding to the image forming condition in image formation, it is possible to set the correction amount suitable for the image forming condition for each image forming condition.
[0015]
According to a sixth aspect of the present invention, the setting means may set the correction amount so that the image density of a region on the recording medium sandwiching the reference position corresponding position in the second direction is continuous. In other words, the correction amount is set so that the image density of the area on the recording medium sandwiching the reference position corresponding position in the second direction is continuous.
[0016]
Accordingly, the correction amount set corresponding to the plurality of positions in the second direction between the two reference position corresponding positions is repeatedly applied to the correction between the plurality of reference position corresponding positions determined repeatedly in the second direction. In this case, the image density is continuous in a region sandwiching the reference position corresponding position, and a natural image can be obtained. For example, among the plurality of positions in the second direction between the two reference position corresponding positions, the density at the position closest to the one reference position corresponding position is set so that the density is continuous in the region sandwiching the reference position corresponding position. The correction amount may be set so that the density at the position closest to the other reference position corresponding position is continuous.
[0017]
Further, as set forth in claim 7, the setting means may set the correction amount so that the image density of a region on the recording medium sandwiching the reference position corresponding position in the second direction is constant.
[0018]
According to an eighth aspect of the present invention, there is provided an image forming apparatus comprising: the correction amount set by the image density correction amount setting device according to any one of the first to seventh aspects; and the electrostatic latent image writing position in the second direction. The physical quantity is corrected based on a predetermined reference position that serves as a reference for the rotational position of the photoconductor, and an image is formed based on the corrected physical quantity.
[0019]
That is, a predetermined relationship between a correction amount set by the image density correction amount setting device and a predetermined reference position serving as a reference for the electrostatic latent image writing position and the rotation position of the photosensitive member in the second direction. The physical quantity is corrected based on the above, and an image is formed based on the corrected physical quantity. Accordingly, the physical quantity that affects the density of the image is corrected based on the correction amount set by the image density correction amount setting device, and the image is formed based on the corrected physical quantity. It is possible to obtain an image having the same. In addition, since the positional relationship between the photosensitive member and the recording medium is determined based on the relationship obtained in advance between the electrostatic latent image writing position and the reference position of the rotational position of the photosensitive member, accurate correction can be performed.
[0020]
Further, the image forming apparatus includes a potential detection unit that detects a surface potential of the photosensitive member and a potential detected by the detection unit of the electrostatic latent image formed based on the corrected physical quantity is a target potential. And a control means for controlling the physical quantity based on the determination result by the determination means. Here, the position in the second direction of the photoconductor where the electric potential is detected by the electric potential detection means may be any of a plurality of positions between the reference positions of the photoconductor, or may be the first position.
[0021]
According to another aspect of the present invention, the image forming apparatus may form a correction amount setting image based on image data for forming an image having an area having a constant density over the second direction.
[0022]
That is, since the correction amount setting image is formed based on the image data for forming an image having an area having a constant density, the correction amount is set so that the density of the area of the correction amount setting image is constant. Can be set. Here, as in the tenth aspect, it is possible to form the correction amount setting image based on at least one image forming condition when forming the image. That is, the correction amount setting image may be formed based on one image forming condition, or the correction amount setting image may be formed based on a plurality of image forming conditions.
[0023]
According to another aspect of the invention, the image forming apparatus includes a writing position detection unit that detects a writing position of the electrostatic latent image, a reference position detection unit that detects a reference position, and a writing position detected by the writing position detection unit. You may make it further provide a calculation means for calculating the relationship between the position and the reference position detected by the reference position detection means, and a storage means for storing the relationship calculated by the calculation means. In this case, the predetermined relationship is a relationship stored in the storage unit.
[0024]
That is, the relationship between the writing position detected by the writing position detection means and the reference position detected by the reference position detection means can be stored in the storage means.
[0025]
Further, when the correction amount setting image is formed, the portion representing the reference position in the correction amount setting image as in claim 12 based on the relationship between the writing position stored in the storage unit and the reference position. An image may be formed, or a partial image representing a plurality of positions between the reference position corresponding positions may be formed in the correction amount setting image as in the thirteenth aspect. Further, the correction amount setting image may further include a partial image (mark) that indicates a position for detecting the density on the correction amount setting image.
[0026]
An image forming system according to a fourteenth aspect of the present invention is the image density correction amount setting device according to any one of the first to seventh aspects, and the image forming system according to any one of the eighth to thirteenth aspects. An image forming apparatus. Here, the image density correction amount setting device may be inside the image forming apparatus or outside the image forming apparatus.
[0027]
According to a fifteenth aspect of the present invention, there is provided an image density correction amount setting method by exposing a cylindrical photosensitive member rotating in a second direction in which a light beam moving in a first direction intersects the first direction. An electrostatic latent image is formed on the photoconductor, and the electrostatic latent image is developed and transferred to the recording medium while the photoconductor rotates, so that the image of the image forming apparatus forms an image on the recording medium. An image density correction amount setting method for setting a correction amount of a physical quantity that affects the density of an image at the time of formation, wherein the recording medium is based on a predetermined reference position that serves as a reference for the rotational position of the photoconductor Individually corresponding to at least one of a plurality of positions in the second direction between two reference position corresponding positions corresponding to the reference position on the recording medium that is continuously determined by the rotation of the photosensitive member. Set.
[0028]
According to a sixteenth aspect of the present invention, there is provided an image density correction amount setting program that exposes a cylindrical photosensitive member rotating in a second direction in which a light beam moving in a first direction intersects the first direction. An image of an image forming apparatus in which an electrostatic latent image is formed on a photosensitive member, and the electrostatic latent image is developed and transferred to a recording medium while the photosensitive member rotates, thereby forming an image on the recording medium. An image density correction amount setting program for causing a computer to set a correction amount of a physical quantity that affects the image density at the time of forming the image, based on a predetermined reference position that serves as a reference for the rotational position of the photoreceptor, Corresponding to at least one of a plurality of positions in the second direction between two reference position corresponding positions corresponding to a reference position on the recording medium determined continuously by rotation of the photosensitive member with respect to the recording medium. Set individually .
[0029]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.
[0030]
FIG. 1 is a schematic diagram of an image forming apparatus provided with an image density correction amount setting apparatus according to an embodiment of the present invention.
[0031]
The image forming apparatus 10 includes photosensitive members 12Y, 12M, 12C, and 12K corresponding to four colors of yellow (Y), magenta (M), cyan (C), and black (K) along the intermediate transfer belt 14. Has been placed. Hereinafter, for the members provided for each color, alphabets indicating the respective colors are attached to the end of the reference numerals, but in the case of description without particularly distinguishing the colors, the alphabet letters at the end of the reference numerals are omitted. . In the vicinity of each photoconductor 12, an optical scanning device 18Y, 18M, which scans a light beam based on image data in the axial direction of each rotating photoconductor 12 and exposes the photoconductor 12 to form a latent image. 18C and 18K are provided. The optical scanning device 18 includes a semiconductor laser as a light source, a rotary polygon mirror that reflects the light beam emitted from the semiconductor laser, and irradiates the photosensitive member 12 with the light beam, a predetermined optical system, and a main scanning start timing. And an SOS sensor for detecting (SOS) (both not shown). Reference position detection sensors 26Y, 26M, 26C and 26K for detecting the reference position of the photoconductor along the rotation direction of the photoconductor 12 and the surface of the photoconductor 12 are arranged around each photoconductor 12Y, 12M, 12C and 12K. Chargers 16Y, 16M, 16C and 16K to be charged, potential sensors 20Y, 20M, 20C and 20K for detecting the charged potential / image potential (exposure potential) on the surface of the photoconductor, and a latent image formed on the photoconductor surface of each color. Developers 22Y, 22M, 22C, and 22K that supply toner to form toner images, and first transfer units 24Y, 24M, 24C, and 24K that transfer toner images to the intermediate transfer belt 14, and transfer to the photoreceptor 12 after transfer. A cleaner (not shown) that removes the remaining toner and a static elimination lamp (not shown) that neutralizes the photoreceptor 12 are provided. To the intermediate transfer belt 14, toner images are sequentially transferred from the photoconductors 12 of the respective colors to form color toner images. A density sensor 32 is provided downstream of the photoreceptors 12Y, 12M, 12C, and 12K in the transport direction of the intermediate transfer belt 14, and detects the density of the patch 30 on the test image. The detected density is compared with a desired density, and the toner supply amount is adjusted based on the comparison result. On the further downstream side of the intermediate transfer belt 14, a second transfer device 34 including two opposed rollers is provided. Between the two rollers of the second transfer unit 34, the toner image on the intermediate transfer belt 14 and the paper 38 discharged from the paper feed unit 36 and conveyed are fed into the intermediate transfer belt 14. The toner image is transferred onto the paper 38. The paper 38 to which the toner image has been transferred is conveyed to a fixing device 40 including a pressure roller 40A and a heating roller 40B and subjected to a fixing process, whereby a desired image is formed on the paper 38.
[0032]
A patch sensor 44 that detects L * a * b (hue, saturation, and brightness) of the patch 42 on the test image is provided downstream of the fixing device 40 in the conveyance direction of the paper 38.
[0033]
Image formation by the image forming apparatus 10 is performed by repeatedly performing predetermined image formation in a predetermined region along the first direction in a second direction that intersects the first direction. That is, by scanning the light beam in the axial direction of the photoconductor 12, an image of a predetermined area is formed, and by rotating the photoconductor 12, image formation of the predetermined area is repeated to form the entire image. On the photoconductor 12, the axial direction of the photoconductor 12 is the main scanning direction, and the rotation direction is the sub-scanning direction. In the present specification, directions on the paper corresponding to the main scanning direction and the sub scanning direction of the photoconductor 12 are referred to as a main scanning direction and a sub scanning direction, respectively.
[0034]
Next, the correction control unit 50 according to the present embodiment will be described with reference to FIG.
[0035]
The correction control unit 50 includes a CPU 52, a memory 54 storing an image density correction amount setting program, a timing setting ASIC 56, and an I / O port 60 that are connected to each other via a bus 58. Detection results from the potential sensors 20Y, 20M, 20C, and 20K, the reference position detection sensors 26Y, 26M, 26C, and 26K, the density sensor 32, and the patch sensor 44 are input to the I / O port 60.
[0036]
The I / O port 60 further includes a user interface unit 62 including an input unit 62A for inputting a correction amount, image forming conditions, and the like, a graphic interface for performing input, and a display unit 62B for displaying input contents. It is connected. The I / O port 60 is further connected to a lighting control unit 64. The lighting control unit 64 controls the amount of exposure by the optical scanning device 18 by controlling the drive current supplied to the semiconductor laser provided in the optical scanning device 18. The correction amount in the present embodiment is a change amount with respect to the current value of the drive current.
[0037]
The image density correction amount setting device according to the present embodiment includes a user interface unit 62 as a setting unit, and a correction control unit 50 including a memory 54 as a storage unit and a CPU 52 as a control unit. Is provided inside.
[0038]
Next, the operation of the present embodiment will be described with reference to the drawings.
[0039]
The image density correction amount setting program according to the present embodiment will be described with reference to the flowchart of FIG. The subroutines of steps 100, 200, 500, 900, and 1200 will be described in detail later.
[0040]
The image density correction amount setting program 90 shown in FIG. 3 is started when an unillustrated correction amount setting start button is pressed by the operator in the user interface unit 62, and the CPU 52 of the correction control unit 50 follows the operator's input to the input unit 62A. Will run.
[0041]
In step 100, an in-plane unevenness confirmation print for confirming current density unevenness (image density distribution) in the main scanning direction and the sub-scanning direction of the image formed by the image forming apparatus as described above is output. Details of the confirmation print output process will be described later. In step 200, the IN / OUT correction amount in the main scanning direction is set, and a correction confirmation print is output. Here, the IN / OUT correction sets a correction amount that linearly changes from the main scanning start point (IN) to the main scanning end point (OUT), and the drive current supplied to the semiconductor laser based on the correction amount is set. Correction is performed to preliminarily correct density unevenness in the main scanning direction of an image formed by the image forming apparatus.
[0042]
In step 300, it is determined whether or not density unevenness (in-plane unevenness) in the main scanning direction has been eliminated. When the operator who has visually confirmed the density unevenness of the image of the correction confirmation print selects a predetermined button described later, it is determined that the in-plane unevenness has been eliminated, and the image density correction amount setting program 90 is terminated. On the other hand, if the operator does not select the predetermined button, it is determined that the in-plane unevenness has not been eliminated, and the process proceeds to step 400. In step 400, it is determined whether or not to return to the state before the IN / OUT correction. A determination is made based on an input by an operator, which will be described later. If the determination is affirmative, the process proceeds to step 1500, the set value is returned before IN / OUT correction, and the image density correction amount setting program 90 is terminated. On the other hand, if the determination is negative, the process proceeds to step 500 with the correction amount after correction being set as the set value without returning to the setting value before correction.
[0043]
In step 500, correction shape / level correction in the main scanning direction is executed. Here, the correction shape in the main scanning direction is a plurality of different combinations of a plurality of positions in the main scanning direction and correction amounts corresponding to each of the plurality of positions, and specifically, the optical scanning device 18. 5 is a basic pattern (representative shape) at each position in the main scanning direction of an image, with a correction amount for correcting the drive current supplied to the semiconductor laser. In this embodiment, ten basic patterns as shown in FIG. 15 are prepared in advance as correction shapes. On the other hand, the correction level is a set of correction amounts prepared in advance to change the inclination of the correction shape, which is a basic pattern. In the present embodiment, a set of nine correction amounts as shown in FIG. 16 is prepared in advance for each correction shape as a correction level. Therefore, by selecting the correction shape, the basic pattern of the correction amount in the main scanning direction can be specified, and the inclination of the basic pattern can be changed by selecting the correction level. An operator sets a correction shape, a correction level, and an image forming condition, and a correction check print for checking the correction based on these settings is output. In step 600, it is determined whether or not density unevenness has been eliminated. Specifically, when the operator who visually confirms the image of the correction confirmation print selects a predetermined button described later, it is determined that the in-plane unevenness has been eliminated, and the image density correction amount setting program 90 is terminated. To do. On the other hand, if the operator does not select the predetermined button, it is determined that the in-plane unevenness has not been eliminated, and the process proceeds to step 700. In step 700, it is determined whether or not to return to the state before the correction shape / level correction. A determination is made based on an input by an operator, which will be described later. If the determination is affirmative, the process proceeds to step 1600, the set value is returned before the correction shape / level setting, and the image density correction amount setting program 90 is terminated. On the other hand, if the determination is negative, the process proceeds to step 800 with the correction amount after correction being set as the set value without returning to the setting value before correction.
[0044]
In step 800, it is determined whether or not manual adjustment in the main scanning direction is performed. Here, the manual adjustment is to individually set the correction amount of the physical quantity (semiconductor laser drive current) that affects the image density during image formation corresponding to a plurality of positions in the main scanning direction of the image. In this case, density unevenness in the main scanning direction of an image formed by the image forming apparatus is corrected.
[0045]
Specifically, the determination in step 800 inquires of the operator whether or not to perform manual adjustment in the main scanning direction by displaying a message on the display unit 62B.
[0046]
If the operator makes an input for manual adjustment to the input unit 62A, the process proceeds to step 900 where manual adjustment in the main scanning direction is executed and a correction confirmation print is output.
[0047]
In step 1000, it is determined whether or not density unevenness has been eliminated. When the operator who has visually confirmed the density unevenness of the image of the correction confirmation print selects a predetermined button described later, it is determined that the in-plane unevenness has been eliminated, and the image density correction amount setting program 90 is terminated. On the other hand, if the operator does not select the predetermined button, it is determined that the in-plane unevenness has not been eliminated, and the process proceeds to step 1100. In step 1100, it is determined whether or not to return to the state before the manual adjustment. A determination is made based on an input by an operator, which will be described later. If the determination is affirmative, the process proceeds to step 1700, the set value is returned before manual adjustment, and the image density correction amount setting program 90 is terminated. On the other hand, if the determination is negative, the process proceeds to step 1200 while the correction amount after correction remains the set value without returning to the setting value before correction.
[0048]
If the determination in step 800 is negative, the process proceeds to step 1200 without performing manual adjustment in steps 900-1100. In step 1200, density correction in the sub-scanning direction is executed. In density correction in the sub-scanning direction, a sub-scanning direction sensor detection pattern is printed out, and the density in the sub-scanning direction is detected. Next, the correction amount in the sub-scanning direction calculated based on the detected density is displayed, and a sub-scanning direction sensor detection pattern is output based on the correction amount. In step 1300, it is determined whether or not density unevenness has been eliminated. When the operator who visually confirms the density unevenness of the sub-scanning direction sensor detection pattern image selects a predetermined button to be described later, it is determined that the in-plane unevenness has been eliminated, and the image density correction amount setting program 90 is executed. finish. On the other hand, if the operator does not select the predetermined button, it is determined that the in-plane unevenness has not been eliminated, and the process proceeds to step 1400. In step 1400, it is determined whether or not to return to the state before the sub-scanning direction correction is performed. A determination is made based on an input by an operator, which will be described later. If the determination is affirmative, the process proceeds to step 1800, the set value is returned before correction in the sub-scanning direction, and the image density correction amount setting program 90 is terminated. On the other hand, if the determination is negative, the image density correction amount setting program 90 is terminated with the correction amount after correction being set as the set value without returning to the setting value before correction.
[0049]
Next, the in-plane unevenness confirmation print output routine in step 100 of the above-described image density correction amount setting program 90 will be described in detail with reference to FIG. In step 101, the in-plane unevenness confirmation print output screen 110 shown in FIG. 5 is displayed on the display unit 62B. The in-plane unevenness confirmation print output screen 110 is configured so that image forming conditions for image formation when outputting a confirmation print can be designated. As the image forming conditions, the color of the material used for forming the image and the fineness of the formed image can be specified. The Color column 112 for setting a color is a color for which density unevenness is to be confirmed. Y, M, C, K, S (special color), R (red), G (green), B (blue), and 3C (gray) Consists of buttons for each color to select from. The Cin column 114 for setting the image density coverage (Input Coverage, hereinafter referred to as Cin) representing the image area ratio per dot of the input image data as a numerical value representing the fineness of the image includes Cin 20% and 60%. From both the “main scanning direction check 20/60% batch” button 114A for outputting a confirmation print for confirming density unevenness in the main scanning direction, and a Cin input field 114B for arbitrarily inputting a Cin value. Become. The Screen column 118 includes buttons 118A to 118F for selecting the screen line number representing the fineness of the image and the screen type. The in-plane unevenness confirmation print output screen 110 further includes a tray column 120 for selecting a paper feed tray, a set number column 122 for setting the number of prints, and a check print for all colors in each of the main scanning direction and the sub-scanning direction. A “main scanning / sub-scanning direction check color batch” button 124 to be output, a “main scanning direction unevenness correction” button 126 for displaying a main scanning direction correction adjustment screen 220 (FIG. 12) described later, and a sub-scanning described later. “To sub-scanning direction unevenness correction” button 128 for displaying the direction density correction screen 1380 (FIG. 24), and “PRINT START” button 130 for instructing output of a confirmation print under the conditions set by the various buttons described above. A “Close” button 132 for closing the screen is provided.
[0050]
In step 102, at any position of the in-plane unevenness confirmation print output screen 110, “The in-plane density distribution can be confirmed. Set the color, Cin, screen, tray, number of confirmation prints, and press the PRINT START button. Please press "screen message appears.
[0051]
In step 103, the operator selects the above-described various buttons provided on the in-plane unevenness confirmation print output screen 110, whereby the in-plane unevenness confirmation print output setting is input. In step 104, the in-plane unevenness confirmation print is output according to the setting input in step 103, and the in-plane unevenness confirmation print output routine is terminated.
[0052]
As an example of an image output as an in-plane unevenness confirmation print, FIGS. 6 to 10 show outputs when the “collective color for main scanning / sub-scanning direction check” button 124 is selected. 6 and 7 are images for confirming density unevenness in the main scanning direction. A single color band having a constant Cin extending along the main scanning direction (horizontal direction in the drawing) is drawn for each Cin and each color, and is repeated in the sub-scanning direction. In FIG. 6, the band 142, the band 144, the band 146, and the band 148 are each Y, M, C, and K, and are formed with 20% Cin. The band 150, the band 152, the band 154, and the band 156 are each formed of Y, M, C, and K, and Cin is 60%. Note that the characters written on the band in FIG. 6 are for explanation of the figure and do not need to be printed on the actual confirmation print, but are printed to facilitate the confirmation by the operator. May be. By visually confirming the density unevenness of each of these bands, the color and Cin that need to be corrected can be determined. In FIG. 7, the band 161, the band 162, the band 163, and the band 164 are 3C (gray), R, G, and B, respectively, and are formed with Cin 20%. The band 165, the band 166, the band 167, and the band 168 are 3C (gray), R, G, and B, respectively, and are formed with Cin 60%.
[0053]
FIG. 8 and FIG. 9 are images for confirming density unevenness in the sub-scanning direction, and a single color band having a constant Cin extending along the sub-scanning direction (vertical direction in the drawing) is each Cin and color. Each is drawn and repeated in the main scanning direction. In FIG. 8, 172 and 174 are bands printed with Cin of 60% and 20%, respectively, and the color is Y. 176 and 178 are bands printed with Cin of 60% and 20%, respectively, and the color is C. In FIG. 9, 182 and 184 are bands printed with Cin of 60% and 20%, respectively, and the color is M. 186 and 188 are bands printed with Cin of 60% and 20%, respectively, and the color is K. As another example of the in-plane unevenness confirmation print, FIG. 10 shows an output when the “main scanning direction check 20/60% batch” button is selected. FIG. 10 is an image for confirming density unevenness in the main scanning direction, and a Cin 20% band and a Cin 60% band are printed for the color selected in the Color column 112. FIG. Note that the characters written on the band in FIG. 10 are for explanation of the figure and do not need to be printed on the actual confirmation print, but are printed for easy confirmation by the operator. May be.
[0054]
In addition to the example described above, by selecting the Screen field 118, it is possible to output a confirmation print for confirming density unevenness for a desired screen line number and screen type. Also, by selecting each of color, Cin, and screen, it is possible to output a confirmation print that arbitrarily combines these.
[0055]
Next, the main scanning direction IN / OUT correction execution routine 200 in step 200 of the above-described image density correction amount setting program 90 will be described in detail with reference to FIG.
[0056]
The main scanning direction IN / OUT correction execution processing routine 200 is started when the “To main scanning direction unevenness correction” button 126 is selected on the in-plane unevenness confirmation print output screen 110 (FIG. 5).
[0057]
In step 201, the main scanning direction correction adjustment screen 220 is displayed on the display unit 62B. The main scanning direction correction adjustment screen 220 is provided with an IN / OUT correction column 222 for setting an IN / OUT correction amount. The IN / OUT correction column 222 includes a correction color display column 222A in which correctable colors are displayed, and an IN / OUT correction amount individual input column for individually inputting an IN / OUT correction amount for a color desired to be corrected. 222B and an update column 222C for designating whether or not the correction amount input to the IN / OUT correction amount individual input column 222B is set as a set value. The value input in the update field 222C is used to determine whether or not to return the set value before IN / OUT correction in step 400 of the image density correction amount setting program 90 described above.
[0058]
The correction amount input to the IN / OUT correction amount individual input field 222B is the difference between the change amount of the exposure amount and the current value of the exposure amount between IN and OUT (the correction amount on the OUT side with reference to the IN side). It is a numerical value expressed as a percentage (%). The correction amount may be a positive number or a negative number. If the number is positive, the correction amount increases from IN to OUT, and if the number is negative, the correction amount decreases from IN to OUT. To do.
[0059]
FIG. 13A shows the relationship between the position in the main scanning direction and the correction amount when the IN / OUT correction amount is + 25% and −25%. The horizontal axis is the position in the main scanning direction, and the vertical axis is the correction amount. The image is divided into six areas 254 from one end to the other end in the main scanning direction. The widths of the areas do not have to be uniform. In FIG. 13A, only the area 5 has a width of 58 mm, and the other areas have a width of 53 mm. When the correction amount is + 25%, the correction amount at OUT increases by 25% with respect to the correction amount at IN as shown by the straight line 250. On the other hand, when the correction amount is −25%, the correction amount at OUT is reduced by 25% with respect to the correction amount at IN as shown by the straight line 252.
[0060]
FIGS. 13B and 13C show correction data created by the correction control unit 50 based on the IN / OUT correction amount input by the operator in the IN / OUT correction amount individual input field 222B. The data includes a correction amount 262 in each area in the main scanning direction (an area between a plurality of positions in the main scanning direction), and an UP / DOWN direction 264 indicating whether the correction amount increases or decreases in the area. Consists of. The correction amount 262 here is the IN / OUT correction amount input by the operator in the IN / OUT correction amount individual input field 222B divided by the number of areas in the main scanning direction. Specifically, when the IN / OUT correction amount input by the operator is 25% and the number of areas is 6, the correction amount 262 of each area is 25 ÷ 6≈4.16. Accordingly, the correction amount 262 represents how much the change amount of the exposure amount (drive current) with respect to the current value changes within the area.
[0061]
The main scanning direction correction adjustment screen 220 is further configured so that a correction amount can be set in accordance with image forming conditions in image formation. As the image forming conditions, the color of the material used for forming the image and the fineness of the formed image can be specified. The Color column 226 (see FIG. 12) for setting a color is provided with a button for each color for selecting a color for outputting the correction confirmation print. The Cin column 230 for setting Cin includes a “20/60% batch for main scanning direction check” button 230A and a Cin input column 230B for inputting Cin. The Screen column 232 includes buttons 232A to 232F for selecting the screen line number and the screen type.
[0062]
The main scanning direction correction adjustment screen 220 further outputs a tray column 234 for selecting a paper feed tray, a set number column 236 for setting the number of prints, and a confirmation print for all colors in the main scanning direction. “Check Color Collective” button 228, “To main scanning direction uneven adjustment (manual adjustment) screen” button 240 for displaying a main scanning direction manual adjustment screen 920 (FIG. 19) described later, and sub-scanning direction density correction described later. “To sub-scanning direction unevenness correction screen” button 242 for displaying screen 1380 (FIG. 24), “PRINT START” button 248 for outputting a confirmation print under the conditions set by the various buttons described above, main scanning direction “Setting” for setting the correction amount input on the correction adjustment screen 220 as a setting value of the correction amount applied at the time of image formation "Close" button 246 for closing tongue 244, and the main scanning direction correction adjustment screen 220 is provided.
[0063]
Whether or not the “set” button 244 has been selected when the “Close” button 246 is selected is stored in the memory 54, and the steps 300 and 600 of the image density correction amount setting program 90 in FIG. And in step 1000, it is used to determine whether or not density unevenness has been eliminated. When the operator who has visually confirmed the density unevenness of the image of the correction check print selects the “CLOSE” button 246 after selecting the “SET” button 244, it is determined that the in-plane unevenness has been eliminated. . On the other hand, if the operator selects the “CLOSE” button 246 without selecting the “set” button 244, it is determined that the in-plane unevenness has not been eliminated.
[0064]
The shape / level correction column 224 and the correction shape column 238 will be described later together with the details of the correction shape / level correction.
[0065]
In step 202, “Implement IN / OUT correction in the main scanning direction. Set the color to be corrected, IN / OUT correction amount, and set Color, Cin, Screen, Tray, Number of copies. If it is on, clear * and press the start button. "Is displayed on the display 62B. “Adjust” refers to the Adjust column 224D of the main scanning direction correction adjustment screen 220, and “*” is automatically displayed in the Adjust column 224D when the correction amount is set by the main scanning direction manual adjustment described later. .
[0066]
In the next step 203, the previous set value is displayed in the IN / OUT correction amount individual input field 222B and the shape / level correction field 224. Further, when “*” is displayed in the above-described Adjust field 224D, the IN / OUT correction amount individual input field 222B and the shape / level correction field 224 are blank, and when “*” is cleared. Displays the previous set value. That is, even when a correction amount is set by main adjustment in the main scanning direction and “*” is displayed in the Adjust column 224D, by correcting “*”, correction in the main scanning direction is performed instead of the correction amount by manual adjustment. The setting of the correction amount on the adjustment screen 220 can be applied.
[0067]
In step 204, the IN / OUT correction amount and the image forming conditions such as the color to be corrected, Cin, and screen are input by the operator via the input unit 62A. The operator visually confirms the confirmation print output by the in-plane unevenness confirmation print output processing 100 to confirm the unevenness in the main scanning direction, and inputs an IN / OUT correction amount so that the unevenness is appropriately corrected.
In step 205, when the “PRINT START” button 248 is selected by the operator, a message “execution in progress” is displayed.
[0068]
In step 206, the current value of the IN / OUT correction amount and the current value of the correction shape / level described later are combined, and the combined value is converted for register input and stored in the register. Since the correction shape / level has not yet been set in step 206, the current value of the correction shape / level is the previous value or the initial value.
[0069]
In step 207, after setting the IN / OUT correction conditions, potential setup is performed. In the potential setup, first, a charging potential is set, an image potential with a light amount based on the correction amount input in step 204 is detected, a light amount that becomes a desired potential is obtained based on the detected image potential, and the light amount and This is done by controlling the optical scanning device 18 by the lighting control unit 64.
[0070]
In step 208, it is determined whether or not a potential abnormality (Fail) has occurred. An abnormality in potential occurs when a desired image potential cannot be obtained because the amount of light exceeds the maximum value. If a potential abnormality occurs and the determination in step 208 is affirmed, the process proceeds to step 211, and a message “Fail in XX color. Correction could not be performed.” Is displayed. In the next step 212, the setting value (correction value) is returned before the IN / OUT correction, and then the IN / OUT correction execution processing routine 200 is terminated.
[0071]
On the other hand, if the potential setup has been performed without any potential abnormality, the determination in step 208 is negative and the process proceeds to step 209. In step 209, the IN / OUT correction amount input in step 204 is set as the current setting value of the correction amount, and whether the value input by the operator as the IN / OUT correction amount is positive or negative, that is, correction. The UP / DOWN direction indicating whether the amount increases or decreases is set as the current set value. These set values are stored in the memory 54. In step 210, a confirmation print is printed out based on the correction amount after IN / OUT correction and the image forming conditions input in step 204, and the main scanning direction IN / OUT correction execution processing routine 200 ends.
[0072]
Next, the main scanning direction correction shape / level correction execution processing routine 500 in step 500 of the above-described image density correction amount setting program 90 will be described in detail with reference to FIG.
[0073]
In step 501, a message “Please set the correction shape, correction level, Cin, Screen, tray, number of sheets and press the PRINT START button” on the display unit 62B displaying the main scanning direction correction adjustment screen 220 is displayed. Is displayed.
[0074]
In step 502, the correction shape / correction level and correction conditions are input by the operator via the input unit 62A. Specifically, an input is made to the shape / level correction field 224 of the main scanning direction correction adjustment screen 220. The shape / level correction field 224 includes a correction color display field 224A, a correction shape input field 224B for inputting a desired shape number among the correction shapes displayed in the correction shape field 238, and a correction for inputting a correction level. The level input field 224C, the Adjustment field 224D in which “*” is displayed when the correction amount is set by manual adjustment, the correction shape / level input in the correction shape input field 224B and the correction level input field 224C An update field 224E for designating whether or not to set a value. The value (Yes or No) input in the update field 224E is used to determine whether or not to return the set value before correction shape / level correction in step 700 of the image density correction amount setting program 90 described above.
[0075]
An example of the correction shape in the present embodiment is shown in FIG. The horizontal axis in FIG. 15 represents the position in the main scanning direction, and the vertical axis represents the correction amount. From one end to the other end of the image in the main scanning direction is divided into six areas 520 of areas 0-5, and a correction amount is determined for each area 520. The corrected shape 522 is No. 1 to No. Ten pieces up to 10 are prepared in advance.
[0076]
Correction shape No. The correction level in 1 is shown in FIG. In FIG. 16, columns represent areas in the main scanning direction and rows represent levels, and the correction amount for each area at each level is shown. The correction amount represents the change amount of the change amount with respect to the current value of the exposure amount in the area. At level 1, the correction amount is 0% in all areas. Level 1 indicates the correction shape No. 1 in FIG. 1 corresponds to the straight line 524. In FIG. 16, the correction amount of level 6 is 6% in all areas. However, since the area 0-2 is in the DOWN direction, the correction amount is decreased, and in the area 3-5, the correction is increased in the UP direction.
[0077]
Level 6 corresponds to the straight line 526 in FIG. The correction amount of level 9 is 8% in all areas, decreases in the DOWN direction in area 0-2, and increases in the UP direction in area 3-5. Level 9 corresponds to the straight line 528 in FIG.
[0078]
Thus, even with the same correction shape, the inclination (change amount) of the correction amount differs depending on the level. The operator visually confirms the confirmation print output by the in-plane unevenness confirmation print output processing 100 to confirm the unevenness in the main scanning direction, and inputs the correction shape / level so that the unevenness is appropriately corrected.
[0079]
In step 503, when the “PRINT START” button 248 is selected by the operator, a message “in execution” is displayed.
[0080]
In step 504, the current value of the IN / OUT correction amount and the current value of the correction shape / level are combined, and the combined value is converted for register input and stored in the register. The synthesis of the IN / OUT correction amount and the correction shape / level will be described with reference to FIG.
[0081]
A straight line 540 in FIG. 17A indicates the correction amount with respect to the position in the main scanning direction when the IN / OUT correction amount is −10%. FIG. 17B corresponds to the straight line 540 and represents the correction amount and the UP / DOWN direction for each area. A straight line 542 in FIG. 1 shows the correction amount for the position in the main scanning direction when the correction level is 3. FIG. 17C corresponds to the straight line 542 and represents the correction amount and the UP / DOWN direction for each area.
[0082]
A straight line 544 in FIG. 17A represents a combination of the IN / OUT correction amount represented by the straight line 540 and the correction amount represented by the straight line 542 and the correction amount based on the correction level. As shown in FIG. 17D, the combined correction amount is a value obtained by adding a sign corresponding to UP / DOWN to the IN / OUT correction amount for each area in FIG. 17B, and FIG. ) Is a value obtained by adding a correction shape for each area and a correction amount based on the correction level to a value added with a sign corresponding to UP / DOWN. In this way, when a plurality of correction amounts are set for the same area, the plurality of correction amounts can be combined. The combination of the IN / OUT correction amount and the correction shape / level is not limited to addition, and may be an average value.
[0083]
In step 505, the potential setup is performed after setting the IN / OUT correction conditions. In step 506, it is determined whether or not a potential abnormality (Fail) has occurred. If a potential abnormality occurs and the determination is affirmed, the process proceeds to step 509, and a message “Fail in XX color. Correction could not be performed.” Is displayed. In the next step 510, after the set value (correction value) is returned before the correction shape / level correction, the main scanning direction correction shape / level correction execution processing routine 500 is terminated.
[0084]
On the other hand, if the potential setup has been performed without any potential abnormality, the determination in step 506 is denied and the process proceeds to step 507. In step 507, the correction shape and the correction level are set as the current set values and stored in the memory 54. In step 508, a confirmation print is printed out under conditions after applying the IN / OUT correction and the correction shape / level correction, and the main scanning direction correction shape / level correction execution processing routine 500 is ended.
Next, the main scanning direction manual adjustment execution processing routine 900 in step 900 of the above-described image density correction amount setting program 90 will be described in detail with reference to FIG. In the main scanning direction manual adjustment execution processing routine 900, when the determination in step 800 of the image density correction amount setting program 90 is affirmed, or in the main scanning direction correction adjustment screen 220, “uneven main scanning direction uneven adjustment (manual adjustment)”. Activated when the “To Screen” button 240 is selected.
[0085]
In step 901, the main scanning direction manual adjustment screen 920 (FIG. 19) is displayed on the display unit 62B. On the main scanning direction manual adjustment screen 920, as shown in FIG. 19, the fine adjustment profile column 922 for fine adjustment of the position in the main scanning direction and the correction amount, and the position adjusted in the fine adjustment profile column 922 are displayed. In addition, a correction position and correction amount table 924 that displays the correction amount and can input the position and the correction amount is provided.
[0086]
The fine adjustment profile column 922 is provided with a color column 928 for selecting a color to be corrected, and a correction profile display column 926 in which the horizontal axis indicates the position in the main scanning direction and the vertical axis indicates the correction amount. In the correction profile display field 926, each of a plurality of positions in the main scanning direction and the corresponding correction amount are displayed. When any one of the Y, M, C, K, and S buttons in the color column 928 is selected, a correction profile is displayed in the correction profile display column 926 based on the current set value of the correction amount for that color.
[0087]
In the correction profile display field 926, a cross mark 932 with crossed arrows is displayed at each position in the main scanning direction where the correction amount is set. In the example of FIG. 19, the main scanning direction includes a plurality of areas defined by a plurality of positions. Seven cross marks 932 from A to G are displayed at a plurality of positions (area boundaries).
[0088]
The cross marks 932 are connected by straight lines, and the straight lines form a correction profile 930. The cross mark 932 can be moved in all directions by being dragged with an input device such as a mouse, and a cross mark can be added by an operation such as a double click. Accordingly, it is possible to individually set correction amounts at a plurality of positions. Further, the correction amount is set at another position by moving the cross mark in the horizontal axis direction, and the correction amount is changed by moving the cross mark in the vertical axis direction.
[0089]
When the cross mark 932 is moved or added, the shape of the correction profile 930 is changed by changing at least one of the position and the correction amount. In the correction position and correction amount table 924, the position and correction amount of each cross mark 932 are displayed for each color. When the cross mark 932 is dragged in the correction profile display field 926, the position and correction amount displayed in the correction position and correction amount table 924 are also changed, and when the cross mark 932 is added, the correction position and correction amount table 924 is displayed. Will also add data.
[0090]
It is also possible to change the position and correction amount of the cross mark 932 by inputting numbers into the correction position and correction amount table 924. In this case, the correction profile 930 is changed according to the input to the correction position and correction amount table 924. The main scanning direction manual adjustment screen 920 is provided with a “to main scanning direction unevenness correction (IN / OUT, shape correction) screen” button 934 for returning to the main scanning direction correction adjustment screen 220.
[0091]
In step 901, the main scanning direction manual adjustment screen 920 (FIG. 19) is displayed, and as an initial setting, a correction profile 930 when Y is selected in the color column 928, and a correction table (correction position and correction amount). Table) 924 is displayed.
[0092]
In step 902, “If fine adjustment (manual adjustment) is required, select a color to be corrected, display a color profile / table, and display the position / correction amount A to be corrected. Press the G cross mark to move and set. "Message is displayed. In step 903, the correction position and the correction amount are input via the input unit 62A. The input of the correction position and the correction amount may be performed by moving the cross mark 932, or may be performed by inputting a number into the correction position and correction amount table 924.
[0093]
In Step 904, “Return to the main scanning direction unevenness correction (IN / OUT, shape / level) screen, set Color, Cin, Screen, tray, number of sheets, and press the PRINT START button” on the display 62B. A message is displayed.
[0094]
In Step 905, the operator selects the “To main scanning direction unevenness correction (IN / OUT, shape correction) screen” button 934, and displays the main scanning direction correction adjustment screen 220 (main scanning direction unevenness correction ( IN / OUT, shape / level) screen) is displayed. “*” Is displayed in the Adjust field 224D, and the IN / OUT correction amount individual input field 222B and the shape / level correction field 224 of the IN / OUT correction field 222 are blank. “*” In the Adjust column 224D indicates that the correction amount is set by the manual adjustment in the main scanning direction.
[0095]
In step 906, when the “PRINT START” button 248 is selected by the operator, a “currently executing” message is displayed. In step 907, the correction position and the correction amount input to the main scanning direction manual adjustment screen 920 in step 903 are converted for register input and stored in the register.
[0096]
In step 908, the potential setup is performed after setting the position and the correction amount. In step 909, it is determined whether or not a potential abnormality (Fail) has occurred. If a potential abnormality occurs and the determination is affirmed, the process proceeds to step 912, and a message “Fail in XX color. Correction could not be performed.” Is displayed. In the next step 913, the set value is returned before manual adjustment, and then the main scanning direction manual adjustment execution processing routine 900 is terminated.
[0097]
On the other hand, if the potential setup has been performed without any potential abnormality, the determination in step 909 is denied and the process proceeds to step 910. In step 910, the correction position and the correction amount input on the main scanning direction manual adjustment screen 920 are set as the current set values and stored in the memory 54. . In step 911, a check print is printed out under the condition after correction by manual adjustment, and the main scanning direction manual adjustment execution processing routine 900 is terminated. Next, the sub-scanning direction correction execution routine 1200 will be described in detail with reference to FIGS. The sub-scanning direction correction execution processing routine 1200 is executed not only in step 1200 of the image density correction amount setting program 90 described above, but also in the in-plane unevenness confirmation print output screen 110 (FIG. 5). This is also executed when the “To” button 128 is selected or when the “To sub-scanning direction unevenness correction screen” button 242 is selected on the main scanning direction correction adjustment screen 220 (FIG. 12).
[0098]
The sub-scanning direction correction execution processing routine 1200 includes a sub-scanning direction density detection processing routine shown in FIG. 20 and a sub-scanning direction correction processing routine shown in FIG. The sub-scanning direction density detection processing routine will be described below with reference to FIG.
[0099]
In step 1201, a sub-scanning direction density detection screen 1230 (FIG. 21) is displayed on the display unit 62B. The sub-scanning direction density detection screen 1230 includes a Color field 1232 for selecting a color for detecting density, a tray field 1234, a Cin input field 1236 for inputting a Cin value, a set number field 1238 for setting the number of prints, and a detection. A “Start detection” button 1240 for starting the image and a “To sub-scanning direction unevenness correction screen” button 1248 for displaying the sub-scanning direction correction screen 1380 are provided. In the density detection result profile 1242 representing the density detection result for the position on the circumference of the photoreceptor in the sub-scanning direction, the density 1244 for each area in the sub-scanning direction is plotted. The density detection result table 1246 displays density values for each area.
[0100]
In step 1202, a message “Detect the density distribution in the sub-scanning direction. Select the color, Cin, tray, and number to be detected and press the detection start button.” Is displayed on the display unit 62B.
[0101]
In step 1203, the operator inputs detection conditions such as color, Cin, tray, and number of sheets via the input unit 62A, and the “detection start” button 1240 is selected.
[0102]
In step 1204, a potential setup is performed. In the next step 1205, it is determined whether or not a potential failure has occurred. If a potential abnormality has occurred and the determination in step 1205 is affirmative, the process proceeds to step 1214, and a subscan is displayed after the message “Fail has occurred in XX. Could not be detected.” The direction concentration detection processing routine is terminated.
[0103]
On the other hand, if the potential setup is performed without any potential abnormality, the determination in step 1205 is negative and the process proceeds to step 1206. In step 1206, the photoconductor reference position is detected by the reference position detection sensor 26. The photoconductor reference position is for determining the reference position of the rotation position of the photoconductor. The reference position detection sensor 26 includes, for example, a light emitter and a light receiver. A notch is provided in the disk that rotates together with the photoconductor, and the optical axis of the light emitter passes through the notch so that the light receiver detects the light, and the photoconductor reference position is detected.
[0104]
In step 1207, the relationship between the image writing timing and the photoconductor reference position detected in step 1206 is calculated and stored in the memory 54 which is a storage unit. The image writing timing is a value controlled by the timing setting ASIC 56.
[0105]
In step 1208, the sub-scanning direction sensor detection pattern 1260 shown in FIG. 22 is printed out on the paper. The sub-scanning direction sensor detection pattern 1260 is written on the paper starting from the pattern image writing position 1264 on the paper conveyed in the paper conveyance direction 1262. The pattern actually written includes a patch 42 for detecting the density (L * a * b) by the patch sensor 44 and a constant density, a mark 1272 for determining the timing for detecting the density of the patch, and a photoconductor reference. A position 1278 and a division position 1280 that divides the circumference of the photosensitive member into 16 areas are shown in FIG. 22 for the sake of convenience of explanation. It is not drawn in the scanning direction sensor detection pattern 1260. The photoconductor reference position 1278 is determined based on the relationship between the image writing timing stored in step 1207 and the photoconductor reference position, and the position on the paper corresponding to the photoconductor reference position is written. .
[0106]
In step 1209, the patch sensor 44 detects L * a * b of the patch 42 of the sub-scanning direction sensor detection pattern 1260 printed out in step 1206. More specifically, the patch at the position corresponding to the patch sensor detection center 1268 at the timing when the mark 1272 is detected by the optical sensor for detecting the reflectance at the position corresponding to the mark sensor detection center 1274 in FIG. The sensor 44 detects L * a * b at the patch detection position 1270.
[0107]
In step 1210, it is determined whether or not an abnormality (Fail) has occurred in the patch sensor 44. If an abnormality occurs and the determination is affirmative, the process proceeds to step 1215, and after the message “Fail in XX. Normal detection failed.” Is displayed, the sub-scanning direction density detection processing routine is executed. finish.
[0108]
If no abnormality occurs in the patch sensor 44 and the determination in step 1208 is negative, the process proceeds to step 1211. In step 1211, the L * a * b detection value is converted into density data.
[0109]
In step 1212, the density at each of the divided positions 1280 with respect to the photoconductor reference position 1278 is calculated, and a density detection result profile is created. Since the division position 1280 and the detection position 1270 do not coincide with each other, the density at each division position 1280 is calculated by interpolating or approximating the density data based on the density data at the detection position 1270.
[0110]
In step 1213, the density detection result profile 1242 and the density detection result table 1246 of all the division positions in the sub-scanning direction are displayed on the sub-scanning direction density detection screen 1230 based on the density at each division position 1280 calculated in step 1212. Then, the sub-scanning direction density detection processing routine ends.
[0111]
The sub-scanning direction correction processing routine will be described below with reference to FIG.
In step 1350, the sub-scanning direction correction screen 1380 (FIG. 24) is displayed on the display unit 62B. The sub-scanning direction correction screen 1380 has a Color column 1382 for selecting a color whose density is to be corrected, a Screen column 1384 for selecting the screen line number and screen type, a Cin input column 1386 for inputting a Cin value, and the number of printed sheets. Set number field 1388 for setting the “Set” button 1390, “Correction clear” button 1392 for clearing the correction, that is, setting the correction value to zero, and “PRINT START” for printing the sub-scanning direction sensor detection pattern 1260. A button 1394 and a “Close” button 1396 are provided.
[0112]
Whether or not the “set” button 1390 is selected when the “Close” button 1396 is selected is stored in the memory 54, and the density in step 1300 of the image density correction amount setting program 90 in FIG. This is used to determine whether or not the unevenness has been resolved. If the operator who has visually confirmed the density unevenness of the correction confirmation print image selects the “Set” button 1390 and then selects the “Close” button 1396, it is determined that the in-plane unevenness has been eliminated. . On the other hand, when the operator selects the “Close” button 1396 without selecting the “Set” button 1390, it is determined that the in-plane unevenness has not been eliminated.
[0113]
In the correction profile display field 1398 representing the correction amount for the position in the sub-scanning direction, the correction profile 1402 is formed by plotting the correction amount for each position in the sub-scanning direction. Positions 0 and 16 in the sub-scanning direction correspond to the photoreceptor reference position 1278 in FIG. Cross marks A-Q are displayed at positions 0 and 16 of the correction profile 1402 together with the correction amount plot. The correction profile 1402 can be displayed for each of the six areas in the main scanning direction by selecting the correction profile display field 1404 for each area in the main scanning direction.
[0114]
The correction amount and position corresponding to the correction profile 1402 are displayed in the correction amount adjustment table 1406.
[0115]
The cross mark AQ displayed in the correction amount profile 1402 can be moved in all directions by being dragged with an input device such as a mouse, and a mark can be added by an operation such as a double click. Is also possible. Accordingly, it is possible to individually set correction amounts at a plurality of positions. Further, the correction amount is set at another position by moving the mark in the horizontal axis direction, and the correction amount is changed by moving the mark in the vertical axis direction.
[0116]
When the cross mark is moved or added, the shape of the correction profile 1402 is changed by changing at least one of the position and the correction amount. The correction amount adjustment table 1406 displays the positions and correction amounts of the cross marks A-Q under the conditions selected in the Color column 1382, the Screen column 1384, and the Cin column 1386. When the cross mark is dragged in the correction profile display field 1398, the position and correction amount displayed in the correction amount adjustment table 1406 are also changed, and when the cross mark (correction amount plot) is added, the correction amount adjustment table 1406 is also displayed. Data is added.
[0117]
It is also possible to change the position of the cross mark and the correction amount by inputting numbers in the correction amount adjustment table 1406. In this case, the correction profile 1402 is changed according to the input to the correction amount adjustment table 1406.
[0118]
In the update field 1408, “Yes” or “No” for designating whether to return to the setting value before performing the sub-scanning direction can be input for each color. The input to the update field 1408 is used for the determination in step 1400 of the image density correction amount setting program 90 described above.
[0119]
In step 1351, a correction amount for each area is obtained based on the density detection result profile created in step 1212 of the sub-scanning direction density detection processing routine and the relationship between the light amount and the density obtained experimentally in advance. Then, a sub-scanning direction correction profile is created. Here, the relationship between the light quantity and the density obtained experimentally in advance is defined as ΔD as the difference between the target density and the detected density, Δexp as the amount of change in the light quantity for obtaining ΔD, and Sensitivity as the sensitivity. Then
Δexp = (1 / Sensitivity) * ΔD
It is represented by
Here, Sensitivity is calculated as follows, where Cin is X and sensitivity coefficient is b0-b6.
Sensitivity = b0 + b1 * X + b2 * X²+ B3 * X³+ B4 * X⁴+ B5 * X⁵+ B6 * X⁶
It should be noted that the division position 1280 for dividing one photoconductor circumference in the sub-scanning direction does not coincide with the detection position 1270 (see FIG. 22), but the density detection created in step 1212 of the sub-scanning direction density detection processing routine. Since the result profile is a density profile at the division position 1280 obtained based on the density at the detection position, the sub-scanning direction correction profile created in step 1351 is also a correction amount profile at the division position 1280. is there. The created profile is displayed as a correction profile 1402 on the sub-scanning direction correction screen 1380 (FIG. 24).
[0120]
In step 1352, the main scanning direction correction amount and the sub-scanning direction correction amount obtained in step 1351 are combined, and the combined correction amount is converted for register input and stored in the register.
[0121]
In step 1353, a potential setup is performed. In the next step 1354, it is determined whether or not a potential failure has occurred. If a potential abnormality has occurred and the determination in step 1354 is affirmative, the process proceeds to step 1362, and after the message “Fail has occurred in XX color. Correction could not be performed.” Is displayed, sub-scanning is performed. The direction correction processing routine is terminated.
[0122]
On the other hand, if the potential setup has been performed without any potential abnormality, the determination in step 1354 is negative, and the process proceeds to step 1355. In step 1355, the sub-scanning direction correction amount obtained in step 1351 is set as the current set value and stored in the memory 54. In step 1356, the sub-scanning direction sensor detection pattern 1260 is printed out under the conditions after the main scanning direction correction and the sub-scanning direction correction.
[0123]
In step 1357, a message “Please manually adjust the correction amount with the cross mark on the sub-scan correction amount adjustment table or the correction amount profile with reference to the photoconductor reference position and division position on the printed pattern”. Is displayed on the display 62B.
[0124]
In step 1358, the correction position and the correction amount are input by the operator via the input unit 62A. The input of the correction position and the correction amount may be performed by moving the cross mark or may be performed by inputting a number into the correction amount adjustment table 1406.
[0125]
In step 1359, only when the “correction clear” button 1392 is selected by the operator, the sub-scanning direction correction profile is cleared (flat) and the correction amount is set to zero. In step 1360, when the “PRINT START” button 1394 is selected by the operator, a “currently executing” message is displayed.
[0126]
In step 1361, the sub-scanning direction sensor detection pattern is printed out under the conditions after manual adjustment. Here, prior to printout, the main scanning direction correction amount and the manually adjusted sub-scanning direction correction amount are combined, converted to register input, and stored in the register, and processing similar to steps 1353 to 1355 is performed. There is a need. When the sub-scanning direction sensor detection pattern is printed out, the sub-scanning direction correction processing routine ends.
[0127]
The synthesis of the main scanning direction correction amount and the sub scanning direction correction amount in step 1352 of the above-described sub scanning direction correction processing routine will be described below with reference to FIGS.
[0128]
25A and 25B show an example of the main scanning direction correction amount in which the IN / OUT correction and the correction shape / level correction are combined. A correction amount is set for each of six areas in the main scanning direction. The correction amount here represents how much the change amount of the exposure amount (drive current) with respect to the current value changes within the area.
FIGS. 26A and 26B show an example in which the sub-scanning direction correction amount is set for each of the 16 areas in the sub-scanning direction. Here, the correction amount represents a change amount with respect to the current value of the exposure amount (drive current). The patch sensor 44 for detecting the density in the sub-scanning direction detects the density at a certain point in the main scanning direction in the sub-scanning direction. Accordingly, the correction amount in the sub-scanning direction is calculated for a certain point in the main scanning direction, and this correction amount is used for combining with all areas in the main scanning direction. That is, the correction amount in the sub-scanning direction is constant in all areas in the main scanning direction corresponding to one area in the sub-scanning direction.
[0129]
FIG. 27 shows a correction amount obtained by combining the main scanning direction correction amount of FIG. 25B and the sub-scanning direction correction amount of FIG. In FIG. 27, a column 1460 indicates an area number in the sub-scanning direction, and a column 1462 indicates a correction amount in the sub-scanning direction shown in FIG. Columns 1464-1474 are composite corrections obtained by adding the main scanning direction correction amounts in the six areas in the main scanning direction of FIG. 26B and the sub-scanning direction correction amounts of column 1462 (FIG. 25B). The amount is shown for each area.
[0130]
A correction amount in the main scanning direction, which is a value representing how much the change amount of the exposure amount (drive current) with respect to the current value changes in the main scanning direction area, is a change amount with respect to the current value of the exposure amount. By adding the correction amount in the sub-scanning direction, the change amount with respect to the current value of the exposure amount at the starting point (area 0, column 1464) in the main scanning direction is determined.
[0131]
For example, in the column 1464 (main scanning area 0) and the column 1460 (sub-scanning direction area number) is 7, the correction amount is −4.5 to −6.5%. This is because the correction amount in the area 0 in the main scanning direction in FIG. 25B is 2% and the direction is DOWN, and the correction amount in the sub-scanning direction area 7 in FIG. 26B is −4.5%. This is because. That is, the amount of change with respect to the current value of the exposure amount at the starting point in the main scanning direction is −4.5%, and changes by 2% from −4.5% to −6.5% in the area 0.
[0132]
Thus, the main scanning direction correction amount is set for each of the six main scanning direction areas, the sub scanning direction correction amount is set for each of the 16 sub scanning direction areas, and the two are combined, as shown in FIG. In this way, the correction amount can be set for each of 6 * 19 = 96 areas to adjust the light amount. Therefore, accurate density unevenness correction can be performed over the entire image plane without requiring a large-scale device such as a scanner. Also, since different values can be set for each area, it is possible to set a correction amount with a high degree of freedom. Furthermore, fine adjustment can be performed by manual adjustment after setting a rough correction amount by IN / OUT correction and correction shape / level correction, so that complicated operation is not required and operability is high.
[0133]
In the sub-scanning direction, an example in which the correction amount is determined based on the density distribution detected by the patch sensor 44 has been described. However, the operator may check the density unevenness for each area by visual observation. In this case, by referring to the photoconductor reference position 1278 drawn in the sub-scanning direction sensor detection pattern 1260 and the division position 1280 that divides the circumference of the photoconductor into a plurality of areas, Since the correspondence with the position on the sheet can be known, a more accurate correction amount can be set.
[0134]
When the density is detected by the patch sensor 44, the density is detected at a certain point in the main scanning direction, and the sub-scanning direction correction amount at the one point is applied to all the main scanning direction areas. However, in the case of visual observation, it is also possible to set correction amounts in the sub-scanning direction at a plurality of points in the main scanning direction. In addition, by installing the patch sensors 44 at a plurality of positions in the main scanning direction, it is possible to detect the density in the sub-scanning direction at a plurality of points in the main scanning direction and calculate the correction amount.
[0135]
Further, in order to check the density unevenness in the sub-scanning direction, the example using the sub-scanning direction sensor detection pattern 1260 in which the patch 42 having a single color and a constant density as shown in FIG. 22 is used has been described. It is not limited to. For example, as shown in FIG. 29, a sub-scanning direction sensor all-color collective detection pattern 1510 in which a plurality of patches drawn in different colors may be used. In the sub-scanning direction sensor all-color collective detection pattern 1510, a Y patch 1512, an M patch 1514, a C patch 1516, and a K patch 1518 are formed. Twelve reference positions 1520 and division positions 1522 that divide the reference positions 1520 are formed. When the sub-scanning direction sensor all-color collective detection pattern 1510 is used, the density is visually confirmed, or a patch sensor for detecting the density of each of the patches 1512 to 1518 is individually provided. You may detect in a lump.
[0136]
The image density correction amount setting program 90 continuously performs in-plane unevenness confirmation print output, main scanning direction IN / OUT correction, main scanning direction correction shape / level correction, main scanning direction manual adjustment, and sub-scanning direction correction. Although the example performed as one procedure has been described, the present invention is not limited to this. For example, the correction main screen 1560 shown in FIG. 30 is displayed, and the operator desires from the “in-plane unevenness confirmation print” button 1562, “main scanning direction unevenness correction” button 1564, and “sub-scanning direction unevenness correction” button 1566. It is also possible to perform each processing independently by selecting the button of the processing to be performed.
[0137]
In the main scanning direction correction shape / level correction, an example in which a confirmation print is output when one level is applied to one shape has been described. However, the present invention is not limited to this. For example, as shown in FIG. 31, the operator can set a level 1614 for each of a plurality of shapes 1612 and press a “PRINT START” button 1618 to simultaneously output confirmation prints of a plurality of corrected shapes. . Further, when the operator presses the “PRINT START” button 1618 after selecting the “all levels” button 1616, the confirmation prints at all levels are output for the shape selected by the shape selection radio button 1620. It may be.
[0138]
In this embodiment, the example in which the correction control unit 50 is provided in the image forming apparatus has been described. However, the present invention is not limited to this. For example, as illustrated in FIG. A communication control unit 15 may be provided, and the communication control unit 15 may be connected to an external personal computer PC50 via the communication line 11. In this case, the PC 50 corresponds to the correction control unit 50, and constitutes an image density correction amount setting device together with a mouse as the input unit 62A and a display as the display unit 62B.
[0139]
Further, the case where the correction amount in the main scanning direction changes linearly will be described, and an example in which the marks 932 are connected with a straight line is also given in the manual adjustment. However, the present invention is not limited to this, and it may be approximated by a straight line or a curve based on the correction amount of the mark position. Alternatively, the curve may be drawn using a known curve drawing method in which the marks are connected by a curve and the curvature is changed by the handle.
[0140]
In this embodiment, the example in which the correction amount is set for each color has been described. However, the present invention is not limited to this. For example, in order to correct the density unevenness caused by the retransfer phenomenon in which the toner returns to the photosensitive drum after the secondary color, a confirmation print is formed by superimposing a plurality of colors, and each color is corrected based on the confirmation print. An amount may be set. In this case, among the photoreceptors corresponding to a plurality of colors used for image formation, the retransfer phenomenon is most likely to occur on the most downstream side, so the correction amount is set in order from the most downstream color. Is preferred. In order to form a confirmation print by superimposing a plurality of colors, a plurality of colors may be selected as image forming conditions.
[0141]
Furthermore, in order to check the color shift that is formed by shifting the image of each color on the paper, a confirmation print is formed by overlaying multiple colors. The image writing timing may be adjusted by the ASIC 56. For example, FIG. 33 shows a schematic diagram in the case of forming gray (3C) by overlapping three colors of Y, M, and C. The band 1630 is formed by sequentially stacking a band 1632, a band 1634, and a band 1636, each formed of Y, M, and C. In the band 1630, the colors of the band 1634 and the band 1632 are seen at the upper and lower ends of the gray portion 1644 formed from three colors, and color misregistration occurs. Therefore, for example, when the writing timing of the band 1632 is adjusted so that writing is performed from the position indicated by the tip of the arrow 1638 and the writing timing of the band 1634 is adjusted so that writing is performed from the position indicated by the arrow 1640, As in a band 1642, an image having no color shift formed only of gray is obtained.
[0142]
In the present embodiment, an example has been described in which the screen is displayed on the display unit 62B and the correction amount is set while referring to the screen. However, the present invention is not limited to this. For example, by looking at the output image of the confirmation print without referring to the screen, the correction amount is input in the order of the predetermined positions corresponding to the main scanning direction and the sub-scanning direction, and the correction amount is set. Also good.
[0143]
Further, the example in which the image density correction amount setting program is stored in advance in the memory 54 has been described. However, the image density correction amount setting program may be external to the image density correction amount setting device. It is also possible to download via the recording medium, record it on a portable recording medium, and take it in from the recording medium.
[0144]
【The invention's effect】
As described above, according to the present invention, the correction amount of the physical quantity that affects the image density at the time of image formation is individually set corresponding to a plurality of positions in a predetermined direction of the image. It has an excellent effect that it can be set arbitrarily.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of an image forming apparatus according to an embodiment of the present invention.
FIG. 2 is a block diagram illustrating a configuration of a correction control unit according to the embodiment of the present invention.
FIG. 3 is a flowchart showing the overall flow of density unevenness correction processing according to the embodiment of the present invention.
4 is a flowchart showing an in-plane unevenness confirmation printout routine in step 100 of FIG.
5 is a diagram showing an in-plane unevenness confirmation print output screen for executing the in-plane unevenness confirmation print output process of FIG. 4; FIG.
FIG. 6 is a main scanning direction detection pattern (for YMCK) according to an embodiment of the present invention.
FIG. 7 is a main scanning direction detection pattern (for RGB, 3C) according to the embodiment of the present invention;
FIG. 8 is a sub-scanning direction detection pattern (for YC) according to an embodiment of the present invention.
FIG. 9 is a sub-scanning direction detection pattern (for MK) according to the embodiment of the present invention.
FIG. 10 is a main scanning direction detection pattern (for Cin 20% and 60% collectively) according to an embodiment of the present invention.
FIG. 11 is a flowchart showing a main scanning direction IN / OUT correction execution processing routine of step 200 of FIG. 3;
12 is a diagram showing a main scanning direction correction adjustment screen for executing the main scanning direction IN / OUT correction processing of FIG. 11 and the main scanning direction correction shape / level correction processing of FIG. 14;
FIG. 13A is a diagram illustrating area division in the main scanning direction and inclination of the IN / OUT correction amount; 13B and 13C are diagrams showing the IN / OUT correction amount for each area corresponding to FIG. 13A. FIG. 13B shows the case where the IN / OUT correction amount is + 25% in the entire main scanning direction. The case where the IN / OUT correction amount is −25% in the entire main scanning direction is shown.
14 is a flowchart showing a main scanning direction correction shape / level correction execution processing routine in step 500 of FIG. 3;
FIG. 15 is a diagram illustrating an example of a correction shape in the main scanning direction.
16 is a correction shape No. 2 is a diagram showing a correction amount (%) for each area at each correction level.
FIG. 17 is a diagram illustrating IN / OUT inclination correction, correction shape / level correction, and a combination result thereof;
18 is a flowchart showing a main scanning direction manual adjustment execution processing routine in step 900 of FIG. 3;
19 is a diagram showing a main scanning direction manual adjustment screen for executing the main scanning direction manual adjustment of FIG. 18;
20 is a flowchart showing a sub-scanning direction density detection processing routine of sub-scanning direction unevenness correction processing in step 1200 of FIG. 3;
FIG. 21 is a diagram showing a sub-scanning direction density detection screen for executing the sub-scanning direction density detection processing routine of FIG. 20;
FIG. 22 is a sub-scanning direction sensor detection pattern according to the embodiment of the present invention.
FIG. 23 is a flowchart showing a sub-scanning direction correction processing routine of sub-scanning direction unevenness correction processing in step 1200 of FIG. 3;
24 is a diagram showing a sub-scanning direction correction screen for executing the sub-scanning direction correction processing routine of FIG. 23. FIG.
FIG. 25 is a diagram illustrating an example of a correction amount in the main scanning direction.
FIG. 26 is a diagram illustrating an example of a correction amount in the sub-scanning direction.
27 is a diagram showing an example of the combination of the main scanning direction correction amount shown in FIG. 25 and the sub-scanning direction correction amount shown in FIG.
FIG. 28 is a diagram showing area division on the surface of the photoreceptor.
FIG. 29 shows a sub-scanning direction sensor all-color batch detection pattern as a modification of the embodiment of the present invention.
FIG. 30 is a diagram showing a screen for individually executing in-plane confirmation print output, main scanning direction unevenness correction, and sub-scanning direction unevenness correction as a modification of the embodiment of the present invention;
FIG. 31 is a diagram showing a screen for outputting correction results in the main scanning direction for a plurality of correction shapes / levels as a modification of the embodiment of the present invention.
FIG. 32 is a diagram illustrating an example in which an image density correction amount setting apparatus is provided outside the image forming apparatus as a modification of the embodiment of the present invention.
FIG. 33 is a schematic diagram showing adjustment of image writing timing as a modification of the embodiment of the present invention.
[Explanation of symbols]
10 Image forming apparatus
62A input section (input means)
62B Display section (display means)
52 CPU (control means, correction amount synthesis means)
54 Memory (storage means)

Claims (16)

An electrostatic latent image is formed on the photosensitive member by exposing a cylindrical photosensitive member rotating in a second direction in which the light beam moving in the first direction intersects the first direction. Correction of a physical quantity that affects the image density when forming an image of an image forming apparatus that forms an image on the recording medium by developing the electrostatic latent image and transferring it to the recording medium while rotating An image density correction amount setting device for setting an amount,
2 corresponding to the reference position on the recording medium which is continuously determined by the rotation of the photosensitive member with respect to the recording medium based on a predetermined reference position serving as a reference for the rotational position of the photosensitive member. An image density correction amount setting device comprising setting means for individually setting corresponding to at least one of a plurality of positions in the second direction between two reference position corresponding positions. Each of the plurality of positions and the correction amount corresponding to each of the plurality of positions are predetermined,
The setting unit individually sets the correction amount by setting a correction amount at another position instead of at least one of the plurality of positions in the second direction of the image. Image density correction amount setting device. Each of the plurality of positions and the correction amount corresponding to each of the plurality of positions are predetermined,
The setting unit individually sets the correction amount by changing the correction amount corresponding to at least one of the plurality of positions in the second direction of the image. The image density correction amount setting device described. Density detecting means for detecting density at a plurality of predetermined positions in the second direction of the image;
The image density correction amount setting apparatus according to claim 2 or 3, wherein the predetermined correction amount is set by the setting means based on the density of the image detected by the density detection means. The image density correction amount setting apparatus according to claim 1, wherein the setting unit sets the correction amount for each image forming condition in the image formation. 6. The image density correction according to claim 1, wherein the setting unit sets the correction amount so that an image density of a region on the recording medium sandwiching the reference position corresponding position in the second direction is continuous. Quantity setting device. 7. The image density correction according to claim 1, wherein the setting unit sets the correction amount so that an image density of a region on the recording medium sandwiching the reference position corresponding position in the second direction is constant. Quantity setting device. 8. The correction amount set by the image density correction amount setting device according to claim 1 and a reference for a writing position of the electrostatic latent image and a rotation position of the photoconductor in the second direction. An image forming apparatus that corrects the physical quantity based on a predetermined relationship between predetermined reference positions and forms the image based on the corrected physical quantity. 9. The image forming apparatus according to claim 8, wherein the image forming apparatus forms a correction amount setting image based on image data for forming an image having an area having a constant density in the second direction. Image forming apparatus. The image forming apparatus according to claim 8 or 9, wherein the correction amount setting image can be formed based on at least one image forming condition when forming the image. Writing position detecting means for detecting the writing position of the electrostatic latent image;
Reference position detecting means for detecting the reference position;
Calculating means for calculating a relationship between the writing position detected by the writing position detecting means and the reference position detected by the reference position detecting means;
Storage means for storing the relationship calculated by the calculation means,
The image forming apparatus according to claim 8, wherein the predetermined relationship is the relationship stored in the storage unit. When forming the correction amount setting image, a partial image representing the reference position is formed in the correction amount setting image based on the relationship between the writing position and the reference position stored in the storage unit. The image forming apparatus according to claim 11. When forming the correction amount setting image, based on the relationship between the writing position and the reference position stored in the storage unit, the correction amount setting image includes the plurality of positions between the reference position corresponding positions. The image forming apparatus according to claim 11, wherein a partial image representing the position of the image is formed. An image density correction amount setting device according to any one of claims 1 to 7,
An image forming apparatus according to any one of claims 8 to 13,
An image forming system comprising: An electrostatic latent image is formed on the photosensitive member by exposing a cylindrical photosensitive member rotating in a second direction in which the light beam moving in the first direction intersects the first direction. Correction of a physical quantity that affects the image density when an image is formed by an image forming apparatus that forms an image on the recording medium by developing the electrostatic latent image and transferring the image to the recording medium while rotating An image density correction amount setting method for setting an amount,
2 corresponding to the reference position on the recording medium, which is continuously determined by the rotation of the photosensitive member relative to the recording medium, based on a predetermined reference position serving as a reference for the rotational position of the photosensitive member. An image density correction amount setting method for individually setting corresponding to at least one of a plurality of positions in the second direction between two reference position corresponding positions. An electrostatic latent image is formed on the photosensitive member by exposing a cylindrical photosensitive member rotating in a second direction in which the light beam moving in the first direction intersects the first direction. Correction of a physical quantity that affects the image density when forming an image of an image forming apparatus that forms an image on the recording medium by developing the electrostatic latent image and transferring it to the recording medium while rotating An image density correction amount setting program for causing a computer to set an amount,
2 corresponding to the reference position on the recording medium which is continuously determined by the rotation of the photosensitive member with respect to the recording medium based on a predetermined reference position serving as a reference for the rotational position of the photosensitive member. An image density correction amount setting program for individually setting at least one of a plurality of positions in the second direction between two reference position corresponding positions.

Images