JP2017156440A - Image forming apparatus and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus and a program that can create correction data for gradation correction to which density unevenness in an image forming surface of a recording medium is added.SOLUTION: An image forming apparatus 10 comprises an image forming part 42 that forms, on a recording medium, a first image that is an image for detecting density unevenness of an image and is formed of a plurality of images with different densities, and a second image that is an image used for creation of correction data for gradation correction and is formed of a plurality of images with different densities. When density unevenness of at least one image of the plurality of images forming the first image formed by the image forming part 42 is out of an allowable range, the image forming apparatus creates the correction data on the basis of the second image that is adjusted to include the density unevenness within an allowable range and formed by the image forming part 42.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an image forming apparatus and a program.

  Patent Document 1 discloses that a photoconductor is exposed by repeatedly performing exposure along a first direction of the photoconductor in a second direction intersecting the first direction, and the exposed photoconductor is used. There is disclosed a color difference distribution calculation device that calculates a color difference distribution corresponding to a density distribution in a direction corresponding to the first direction of an image formed in this manner. This color difference distribution calculation device is obtained from the density detected by the detection means based on a detection means for detecting the density of the image and a previously determined relationship between the density of the image and the color difference corresponding to the density. Computing means for computing a color difference distribution corresponding to the density distribution in the direction corresponding to the first direction.

  Japanese Patent Application Laid-Open No. 2004-228620 has an arrangement unit that arranges a color correction image corresponding to the size of each area in each area divided into a predetermined number of divisions, and is formed in each area of the recording medium. An image processing apparatus is disclosed that includes correction amount calculation means for calculating a correction amount for each region based on colorimetric data obtained by measuring the color correction image and a target value. The image processing apparatus further includes a difference calculating unit that calculates a value indicating a difference between the regions of the correction amount calculated for each region by the correction amount calculating unit. In addition, when the value indicating the difference between the correction amounts calculated by the difference calculating unit is equal to or less than a predetermined value, the image processing apparatus stores the same correction amount for a plurality of areas related to the correction amount. And color correction means for performing color correction for each region using the correction amount stored in the storage means.

Japanese Patent No. 4487524 JP 2014-086930 A

  An object of the present invention is to provide an image forming apparatus and a program capable of generating correction data for gradation correction in consideration of density unevenness in an image forming surface of a recording medium.

  In order to achieve the above object, an image forming apparatus according to claim 1 is an image for detecting density unevenness of an image, a first image composed of a plurality of images each having a different density, and a tone correction image And forming a second image composed of a plurality of images each having a different density on a recording medium, and a plurality of images constituting the first image formed by the forming means. When the density unevenness of at least one image of the image is outside the allowable range, the correction data is obtained based on the second image formed by adjusting the density unevenness within the allowable range by the forming unit. Generating means for generating.

  According to a second aspect of the present invention, in the first aspect of the invention, the generation unit may cause density unevenness of at least one of a plurality of images constituting the first image formed by the forming unit. If the density of each image constituting the first image is outside the allowable range, the density of the first image formed by the forming unit is set to the density of the input image data when forming the first image. The correction data for each density is generated based on the second image formed by performing the matching or approaching adjustment on the forming means, and the correction data is generated by synthesizing the generated correction data for each density. .

  According to a third aspect of the present invention, in the invention according to the first or second aspect, the forming unit forms at least one of a plurality of images constituting the first image formed by the forming unit. When the density unevenness of the second image is outside the allowable range, the second image is divided into a number of regions corresponding to the number of density steps of the first image, and the density unevenness in the second image is outside the allowable range. An area corresponding to the density level of the image constituting the first image is formed on the recording medium.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the forming unit forms the first image without performing gradation correction. The second image is formed by performing gradation correction.

  On the other hand, in order to achieve the above object, a program according to claim 5 is for causing a computer to function as a generation unit of the image forming apparatus according to any one of claims 1 to 4. .

  According to the first and fifth aspects of the invention, it is possible to generate correction data for gradation correction that takes into account density unevenness in the image forming surface of the recording medium.

  According to the second aspect of the present invention, it is possible to generate correction data for gradation correction in consideration of density unevenness in the image forming surface of the recording medium for each density of the first image.

  According to the third aspect of the present invention, it is possible to reduce the amount of consumption of consumables used for forming the image as compared with the case where the second image is formed without being divided.

  According to the fourth aspect of the present invention, it is possible to avoid the influence caused by the correction of the first image.

1 is a block diagram illustrating a configuration of an image forming apparatus according to an embodiment. It is a top view which shows an example of the test chart which concerns on embodiment. 6 is a graph showing an example of the relationship between the formation position in the sheet crossing direction and the density of the output image when the density of the input image according to the embodiment is 60%. 6 is a graph showing an example of the relationship between the formation position in the cross direction of paper and the density of an output image when the density of an input image according to an embodiment is 20%. 6 is a graph showing an example of the relationship between the formation position in the sheet crossing direction and the density of the output image when the density of the input image according to the embodiment is 60%. 6 is a graph showing an example of the relationship between the formation position in the cross direction of paper and the density of an output image when the density of an input image according to an embodiment is 20%. It is a flowchart which shows the flow of a process of the correction data generation process program which concerns on embodiment. 6 is a graph for explaining density adjustment by an image forming unit according to an embodiment. 6 is a graph for explaining density adjustment by an image forming unit according to an embodiment. It is a top view which shows an example of the test chart corresponding to the low density | concentration which concerns on embodiment. It is a top view which shows an example of the test chart corresponding to the high density | concentration which concerns on embodiment. It is the schematic which shows an example of the error notification screen which concerns on embodiment.

  DETAILED DESCRIPTION Hereinafter, exemplary embodiments for carrying out the present invention will be described in detail with reference to the drawings.

  With reference to FIG. 1, a configuration of an image forming apparatus 10 according to the present exemplary embodiment will be described. In the following, when yellow is represented by Y, magenta color is represented by M, cyan color is represented by C, and black is represented by K, each component and toner image need to be distinguished for each color. In the following description, reference numerals (Y, M, C, K) of colors corresponding to are attached. Further, in the following, when the component parts and the toner image are collectively referred to without being distinguished for each color, the description of the color at the end of the code is omitted.

  As shown in FIG. 1, the image forming apparatus 10 according to the present embodiment includes a control unit 12, a paper supply unit 40, an image forming unit 42, an image reading unit 44, a paper discharge unit 46, a communication line I / F (InterFace ) 48 and an operation display unit 50.

  The control unit 12 according to the present embodiment includes a CPU (Central Processing Unit) 20 that controls the overall operation of the image forming apparatus 10 and a ROM (Read Only Memory) 22 in which various programs, various parameters, and the like are stored in advance. I have. The control unit 12 also includes a RAM (Random Access Memory) 24 used as a work area when the CPU 20 executes various programs, a non-volatile storage unit 26 such as a flash memory, and an input / output I / F 28. .

  The CPU 20, the ROM 22, the RAM 24, the storage unit 26, and the input / output I / F 28 are connected to each other via a bus 30 such as an address bus, a data bus, and a control bus. Further, a paper supply unit 40, an image forming unit 42, an image reading unit 44, a paper discharge unit 46, a communication line I / F 48, and an operation display unit 50 are connected to the input / output I / F 28.

  The sheet supply unit 40 according to the present embodiment includes a sheet storage unit on which a plurality of sheets P (see also FIG. 2) as an example of a recording medium are stacked, and a single sheet P stacked on the sheet storage unit. A supply mechanism and the like are provided that are taken out and supplied to an image forming unit 42 described later.

  The image forming unit 42 according to the present embodiment includes Y, M, C, and K image forming units. Each color image forming unit includes an image carrier, a charger that charges the surface of the image carrier, and an exposure device that irradiates exposure light that forms an electrostatic latent image on the surface of the charged image carrier. Each color image forming unit includes a developing unit that develops an electrostatic latent image formed on the surface of the image holding member by irradiation of exposure light from an exposure device with a developer and visualizes the image as a toner image.

  Further, the image forming unit 42 includes an endless intermediate transfer belt, and a primary transfer roll disposed on the opposite side of each color image holding body with the intermediate transfer belt interposed therebetween. With the above configuration, the toner images of each color Y, M, C, and K, which are sequentially formed on the image carrier of each color image forming unit, are transferred onto the intermediate transfer belt in a multiple manner by the primary transfer roll of each color. The

  The image forming unit 42 is provided on the opposite side of the auxiliary roll and the intermediate transfer belt, and transfers the toner image transferred on the intermediate transfer belt onto the conveyed paper P. It has a roll. The secondary transfer roll is grounded, and the auxiliary roll forms a counter electrode of the secondary transfer roll. By applying a secondary transfer bias to the auxiliary roll, the toner image is transferred from the intermediate transfer belt to the paper P. Transcribed.

  Further, the image forming unit 42 includes a fixing device that fixes the toner image transferred onto the paper P by pressurizing and heating.

  The image reading unit 44 according to the present embodiment includes an image reading sensor such as a CCD (Charge Coupled Device) line sensor. The image reading unit 44 reads the image formed on the paper P by the image forming unit 42 and outputs the image data obtained by reading to the CPU 20 via the input / output I / F 28.

  The paper discharge unit 46 according to the present embodiment has a discharge unit from which the paper P is discharged and the paper P on which the image is formed by the image forming unit 42 and the image read by the image reading unit 44 on the discharge unit. A discharge mechanism for discharging is provided.

  The communication line I / F 48 according to the present embodiment transmits / receives communication data to / from an external device. The operation display unit 50 according to the present embodiment accepts an instruction from the user to the image forming apparatus 10, while displaying various information related to the operation status of the image forming apparatus 10 to the user. The operation display unit 50 includes, for example, a display button that realizes reception of an operation instruction by executing a program, a display provided with a touch panel on a display surface on which various information is displayed, and hardware keys such as a numeric keypad and a start button. including.

  By the way, the image forming apparatus 10 according to the present embodiment is equipped with a generation function for generating correction data used for gradation correction for correcting gradation characteristics of image data indicating an image to be formed.

  With reference to FIG. 2, the test chart TC formed on the paper P by the image forming unit 42 in order to realize the generation function will be described. As shown in FIG. 2, the test chart TC according to the present embodiment includes a first image G1C, G1M, G1Y, G1K, and a second image G2.

  The first image G1 according to the present embodiment is an image for detecting unevenness in image density, and is composed of a plurality of images having different densities. Specifically, the first image G1 is a band-shaped image having a plurality of levels (two levels in the present embodiment) for each color of Y, M, C, and K. In FIG. 2, the symbol “H” is added to the end of the first image G1 having a high density (60% density in the present embodiment), and a low density (20% density in the present embodiment). A symbol “L” is attached to the end of the first image G1.

  The first image G1 is a belt-like image having a longitudinal direction in a crossing direction (hereinafter simply referred to as “crossing direction”) that intersects (in the present embodiment, orthogonal) with the transport direction of the paper P. The image has a uniform density. The term “orthogonal” as used herein means orthogonality within a range including errors such as the installation positions of the component parts in the image forming apparatus 10. In addition, the first image G1 is formed in a range that covers a range in the crossing direction of the image forming area of the paper P.

  On the other hand, the second image G2 according to the present embodiment is an image used to generate correction data, and is an image in which a plurality of patch images PG having a rectangular shape and different densities and colors are arranged in a matrix. ing.

  In the image forming apparatus 10 according to the present embodiment, image data indicating the test chart TC (hereinafter referred to as “test image data”) is stored in the storage unit 26 in advance. In the following, the image data of the portion corresponding to the first image G1 of the test image data is referred to as “first image data”, and the image data of the portion corresponding to the second image G2 is referred to as “second image data”. In the image forming apparatus 10 according to the present embodiment, correction data generated using the second image G2 at the time of shipment from a factory, for example, is stored in advance in the storage unit 26 as initial data.

  By the way, in the image forming apparatus 10 according to the present exemplary embodiment, in the image formed on the paper P by the image forming unit 42, density unevenness may occur in the image forming surface of the paper P. Further, this uneven density may vary depending on the density of the image. This density unevenness will be described with reference to FIGS. Note that FIG. 3 shows the formation position and density Dout in the intersecting direction of the output image formed at a uniform density on the paper P when the density Cin of the input image is high (here, 60% density) for a certain color. An example of the relationship is shown. 4 shows the formation position of the output image formed at a uniform density on the paper P in the crossing direction when the density of the input image is low (20% density in this case) for the same color as in FIG. An example of the relationship with the density Dout is shown.

  On the other hand, FIGS. 5 and 6 correspond to FIGS. 3 and 4 on a one-to-one basis, respectively, and the output image formed on the paper P in another example of the same color as the example shown in FIGS. 3 and 4. 2 shows an example of the relationship between the formation position and the concentration Dout with respect to the crossing direction.

  As shown in FIGS. 3 and 4, even if the density variation along the crossing direction in the image forming surface is relatively small for the high density image, the density variation is relatively small for the low density image. May be big. On the other hand, as shown in FIGS. 5 and 6, even if the density variation along the intersecting direction in the image forming surface is relatively large for the high density image, the density variation is low for the low density image. Sometimes it is relatively small. As described above, the density unevenness (hereinafter simply referred to as “density unevenness”) along the intersecting direction in the image forming surface of the output image may vary depending on the image density.

  In this case, if the correction data is generated without considering the density and density unevenness of the output image, the accuracy of the correction data may be reduced. Therefore, in the image forming apparatus 10 according to the present embodiment, density unevenness is detected based on the first image G1, and correction data is generated based on the second image G2 in consideration of the detected density unevenness.

  Next, the operation of the image forming apparatus 10 according to the present embodiment will be described with reference to FIG. FIG. 7 is a flowchart showing a processing flow of the correction data generation processing program executed by the CPU 20. The correction data generation processing program is executed, for example, when an instruction to start execution is input by the user via the operation display unit 50 or every time an image is formed on a predetermined number (for example, 1000 sheets) of paper P. Etc. are executed. The correction data generation processing program is installed in the ROM 22 in advance.

  In step 100 of FIG. 7, the CPU 20 initializes the counter to 0 (zero). In the next step 102, the CPU 20 reads test image data and correction data stored in the storage unit 26. Then, the CPU 20 does not perform gradation correction on the first image data, performs gradation correction on the second image data using the correction data, and controls the image forming unit 42 to test the test chart. TC is formed on the paper P.

  In the next step 104, the CPU 20 controls the image reading unit 44 to read the test chart TC formed on the paper P and obtain image data obtained by reading. In the following, the portion corresponding to the first image G1 of the image data obtained by reading is referred to as “first read image data”, and the portion corresponding to the second image G2 is referred to as “second read image data”. . In the following, the first image G1 indicated by the first image data is referred to as “input first image G1”, and the first image G1 indicated by the first read image data is referred to as “output first image G1”. Further, hereinafter, the second image G2 indicated by the second image data is referred to as “input second image G2”, and the second image G2 indicated by the second read image data is referred to as “output second image G2”.

  In step 106, the CPU 20 determines whether the density unevenness of the output first image G1 indicated by the first read image data acquired in step 104 is within an allowable range for each color of Y, M, C, and K. judge. Specifically, for example, the CPU 20 determines that the density difference between the color regions formed at corresponding positions between the input first image G1 and the output first image G1 is the density of the input first image G1 in advance. It is determined whether or not it is within a predetermined ratio range (for example, within a range of ± 10%).

  In this step 106, for example, the CPU 20 derives the similarity between the input first image G1 and the output first image G1, and the derived similarity is equal to or greater than a predetermined threshold (for example, 90%). By determining whether or not the density unevenness of the output first image G1 is within an allowable range, it may be determined. Further, for example, the CPU 20 may generate a density histogram from the output first image G1, and determine whether or not the density unevenness of the output first image G1 is within an allowable range. If the determination at step 106 is affirmative, the CPU 20 proceeds to step 128. If the determination is negative, the CPU 20 proceeds to step 108.

  In this embodiment, as an example, correction data is generated in step 128 to be described later for colors for which the density unevenness of both the high density and low density output first images G1 is determined to be within the allowable range. . On the other hand, the processing from step 108 to step 126 described later is performed for the color for which the density unevenness of at least one of the high density and low density output first images G1 is determined to be outside the allowable range.

  In the processing from step 108 to step 126 below, the density of each stage of the first image G1 (in this embodiment, two stages of high density and low density) is the target (hereinafter referred to as “target density”). .) Is repeatedly executed.

  In step 108, the CPU 20 controls the image forming unit 42, and the density unevenness of the output first image G1 indicated by the first read image data corresponding to the target density acquired in the immediately preceding step 104 or step 110 is obtained. The test chart TC is formed on the paper P after adjusting the density of the image formed by the image forming unit 42 so as to be within the allowable range.

  Specifically, when the target density is a low density, the CPU 20 uses the density Dout of the output first image G1 as the density of the input first image G1 at each formation position in the cross direction (see FIG. 8 as an example). 20%), the image forming unit 42 is adjusted so as to match or approach, and the test chart TC is formed on the paper P. Similarly, when the target density is high, the CPU 20 uses the density Dout of the output first image G1 as the density (60% of the input first image G1) at each formation position in the intersecting direction as shown in FIG. 9 as an example. The test chart TC is formed on the paper P by adjusting the image forming unit 42 so as to match or be close to.

  In the present embodiment, the density of the output first image G1 is adjusted along the cross direction by adjusting the amount of exposure light irradiated by the exposure device of the image forming unit 42 along each image forming position in the cross direction. However, the present invention is not limited to this. If the density of the output first image G1 can be adjusted along the crossing direction, the density of the output first image G1 is adjusted along the crossing direction by adjusting the components of the image forming unit 42 other than the exposure apparatus. May be.

  Further, in the present embodiment, when the test chart TC is formed in this step 108, the CPU 20 sets the second image G2 to a number corresponding to the number of density steps of the first image G1 for the second image G2. An area corresponding to the target density in the second image G <b> 2 is formed on the paper P. Specifically, for example, the CPU 20 uses the second image G2 as a second patch image PG having a density TH1 (for example, 50%) or more and 100% or less according to the density level of the first image G1. The image G2H is divided into a second image G2L composed of a patch image PG having a density exceeding 0% and less than the threshold TH1.

  Then, when the target density is a low density, the CPU 20 controls the image forming unit 42 to form the second image G2L on the paper P as the second image G2, as shown in FIG. 10 as an example. On the other hand, when the target density is high, the CPU 20 controls the image forming unit 42 to form the second image G2H on the paper P as the second image G2, as shown in FIG.

  In the next step 110, the CPU 20 controls the image reading unit 44 to read the test chart TC formed on the paper P and obtain image data obtained by reading. In the next step 112, the CPU 20 allows the density unevenness of the output first image G <b> 1 indicated by the first read image data acquired in step 110 for the first image G <b> 1 of the target density to be in the allowable range, as in step 106. It is determined whether it is in. When this determination is a negative determination, the CPU 20 proceeds to step 122, while when the determination is affirmative, the CPU 20 proceeds to step 114.

  In step 114, the CPU 20 determines the density of the image formed on the paper P based on the test image data (second image data) stored in the storage unit 26 and the second read image data acquired in step 110. Original data for generating correction data that matches or approaches the target density is generated. In the next step 116, the CPU 20 determines whether or not the original data has been generated in step 114 for all of the multiple levels of density of the first image G1. When this determination is a negative determination, the CPU 20 returns to step 108, while when the determination is affirmative, the CPU 20 proceeds to step 118. When the processing from step 108 to 114 is executed, in step 108, a density that has not been processed until then is set as a processing target.

  In step 118, the CPU 20 combines the original data of each density generated in step 114 into one original data. In the next step 120, the CPU 20 generates correction data from the original data synthesized in step 118 and stores (updates) the correction data in the storage unit 26, and then ends the correction data generation process. That is, in this step 120, for the low density portion, correction data is generated based on the second image G2L formed by adjusting the low density first image G1 to be within the allowable range. On the other hand, in step 120, for the high density portion, correction data is generated based on the second image G2H formed by adjusting the high density first image G1 to be within the allowable range.

  On the other hand, in step 122, the CPU 20 increments the counter by 1 (counter ← counter + 1). In the next step 124, the CPU 20 determines whether or not the counter is greater than or equal to the threshold value TH2. If the determination is negative, the CPU 20 returns to step 108, but if the determination is affirmative, the CPU 20 proceeds to step 126. The threshold value TH2 is a value for preventing the processes in steps 108 to 112 and step 122 from being repeated infinitely, and may be set as appropriate.

  In step 126, the CPU 20 notifies that there is an abnormality in the density of the image formed by the image forming unit 42, and then ends the correction data generation process. Specifically, the CPU 20 displays on the display of the operation display unit 50 an error notification screen for notifying that an abnormality has occurred in the density of the image formed by the image forming unit 42.

  FIG. 12 shows an example of an error notification screen according to the present embodiment. As shown in FIG. 12, in the error notification screen according to the present embodiment, information indicating that an abnormality has occurred in the density of the image formed by the image forming unit 42, the color in which the abnormality has occurred, Information indicating the density is displayed. Here, when ending the display of the error notification screen, the user designates an end button displayed at the bottom of the error notification screen.

  In step 126, the CPU 20 may notify that the abnormality has occurred by voice or the like. Further, the CPU 20 may notify the fact that the abnormality has occurred by controlling the image forming unit 42 to form information indicating that the abnormality has occurred on the paper P. Further, the CPU 20 may notify that the abnormality has occurred by transmitting information indicating that the abnormality has occurred to a maintenance staff or the like via a network. Moreover, you may combine two or more of these some alerting | reporting methods.

  On the other hand, in step 128, the CPU 20 determines the image formed on the paper P based on the test image data (second image data) stored in the storage unit 26 and the second read image data acquired in step 104. After the correction data for making the density coincide with or approaching the target density is generated and stored (updated) in the storage unit 26, the correction data generation process is terminated.

  In the above embodiment, the case has been described where the second images G2H and G2L divided in step 108 according to the number of density levels of the first image G1 are formed on the paper P, but the present invention is not limited to this. For example, the second image G <b> 2 may be formed on the paper P in step 108 as in step 102. In the case of this embodiment, when the original data is generated in step 114, image data obtained by dividing the second read image data in the same manner as in step 108 may be used.

  Further, in this embodiment, for example, in step 112, it is determined whether or not the density unevenness is within the allowable range for the density other than the target density, and the density for which the density unevenness is determined to be within the allowable range is determined in step 110. The original data may be generated in step 114 using the acquired second read image data.

  In the above embodiment, for example, for the density at which the density unevenness is determined to be within the allowable range in step 106, the original data is used in the same manner as in step 114 using the second read image data acquired in step 104. It is good also as a form which produces | generates.

In the above-described embodiment, the case where two levels are applied as the number of density levels of the first image G1 has been described. However, the present invention is not limited to this. For example, three or more levels may be applied as the number of density levels of the first image G1. In this embodiment, when the number of steps of density of the first image G1 is three, an embodiment in which 30%, 60% and 90% density images are formed on the paper P as the first image G1 is exemplified. Is done. Further, in this embodiment, the second image G2 corresponding to the density stage of the first image G1 formed in step 108 is more than 0% and less than 33%, more than 33% and less than 66%, more than 66%. An example in which the second image G2 composed of patch images PG having a density of 100% or less is formed on the paper P is exemplified.

  Moreover, although the said embodiment demonstrated the case where the strip | belt-shaped image which makes a cross direction a longitudinal direction was applied as 1st image G1, it is not limited to this. For example, as the first image G1, a belt-like image having the transport direction as the longitudinal direction may be applied. In the case of this embodiment, density unevenness along the transport direction is detected based on the density of the output first image G1.

  Moreover, in the said embodiment, it is good also as a form which can set the target density | concentration applied by the process from step 108 to step 126 by a user. For example, in the above-described embodiment, when a user who frequently forms a high density image sets the target density as a high density, the processing from step 108 to step 126 is executed only for the high density. Illustrated.

  In the above-described embodiment, the case where the test chart is read by the image reading unit 44 provided inside the image forming apparatus 10 has been described. However, the present invention is not limited to this. The test chart may be read by an image reading device external to the image forming apparatus 10. As an example of this case, the image forming apparatus 10 obtains image data obtained by reading a test chart by an external image reading apparatus from the image reading apparatus, and the above embodiment is based on the obtained image data. The form which performs correction data generation processing similarly to is illustrated.

  Further, in the above embodiment, the process of performing gradation correction on a part of the test image data (second image data) in step 102 and step 108 and not performing gradation correction on the other part (first image data). Alternatively, it may be executed by an image processing apparatus outside the image forming apparatus 10. As an example of this case, an external image processing apparatus acquires correction data and test image data from the image forming apparatus 10, performs gradation correction on a part of the acquired test image data, and performs gradation correction on other parts. An example of generating image data that has not been transmitted and transmitting it to the image forming apparatus 10 is illustrated.

  In the above-described embodiment, a case has been described in which the occurrence of an abnormality in the density of an image formed by the image forming unit 42 has been described. However, the present invention is not limited to this. For example, it is good also as a form which memorize | stores in the memory | storage part 26 as log information that the said abnormality has generate | occur | produced. In the case of this embodiment, a maintenance staff or the like grasps that the abnormality has occurred by referring to the log information during maintenance work of the image forming apparatus 10 or the like.

  Moreover, although the said embodiment demonstrated the case where the correction data generation process program was previously installed in ROM22, it is not limited to this. For example, the correction data generation processing program may be provided by being stored in a storage medium such as a CD-ROM (Compact Disk Read Only Memory) or provided via a network.

  Furthermore, in the above-described embodiment, the correction data generation process is described as being realized by a software configuration using a computer by executing a program, but the present invention is not limited to this. For example, the correction data generation process may be realized by a hardware configuration or a combination of a hardware configuration and a software configuration.

  In addition, the configuration (see FIG. 1) of the image forming apparatus 10 described in the above embodiment is merely an example, and unnecessary portions are deleted or new portions are added within the scope not departing from the gist of the present invention. Needless to say, you can also.

  The processing flow of the correction data generation processing program described in the above embodiment (see FIG. 7) is also an example, and unnecessary steps can be deleted or new steps can be performed without departing from the gist of the present invention. Needless to say, they may be added or the processing order may be changed.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 12 Control part 20 CPU
22 ROM
26 Storage Unit 42 Image Forming Unit 44 Image Reading Unit 50 Operation Display Unit G1 First Image G2 Second Image P Paper

Claims (5)

An image for detecting density unevenness in an image, a first image composed of a plurality of images each having a different density, and an image used for generating correction data for gradation correction, each having a plurality of images having different densities Forming means for forming a configured second image on a recording medium;
When the density unevenness of at least one of the plurality of images constituting the first image formed by the forming unit is outside the allowable range, the forming unit adjusts the density unevenness to be within the allowable range. Generating means for generating the correction data based on the second image formed in the above manner;
An image forming apparatus. The generation unit is configured to determine the density of each image constituting the first image when the density unevenness of at least one of the plurality of images constituting the first image formed by the forming unit is outside an allowable range. The second image formed by adjusting the density of the first image formed by the forming unit to match or approach the density of the input image data when forming the first image. The image forming apparatus according to claim 1, wherein the correction data for each density is generated based on the image data, and the correction data is generated by synthesizing the generated correction data for each density. The forming unit converts the second image to a density of the first image when density unevenness of at least one of the plurality of images constituting the first image formed by the forming unit is out of an allowable range. 2. The area is divided into a number corresponding to the number of stages, and an area corresponding to a density level of an image constituting the first image in which density unevenness in the second image is outside an allowable range is formed on a recording medium. Alternatively, the image forming apparatus according to claim 2. The image according to any one of claims 1 to 3, wherein the forming unit forms the first image without performing gradation correction, and forms the second image by performing gradation correction. Forming equipment.   The program for functioning a computer as a production | generation means of the image forming apparatus in any one of Claims 1-4.