JP2013218034A - Image forming apparatus - Google Patents

Abstract

An image forming apparatus capable of suppressing a rapid change in color even when a correction amount is large and suppressing a decrease in image quality.
An image forming apparatus detects a correction amount from a patch image for adjustment in order to adjust an image forming condition. When the correction amount is detected, when images are continuously formed on a plurality of sheets, the correction amount is gradually increased from the correction amount smaller than the detected correction amount, and the correction amount is reflected in the image forming conditions. Then, the image forming conditions are corrected step by step. The image forming apparatus forms an image based on an image forming condition in which the correction amount is reflected.
[Selection] Figure 5

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus having a function of adjusting image forming conditions.

  2. Description of the Related Art Conventionally, image forming apparatuses such as electrophotographic copying machines and laser printers that transfer an electrostatic latent image formed on the surface of a photosensitive drum onto a recording medium after developing with toner are known. A toner image is formed with each of a plurality of color toners such as Y (yellow), M (magenta), C (cyan), and K (black), and a color image is formed by superimposing these toner images. There is a color image forming apparatus configured to form. In such a color image forming apparatus, when the transfer position of the toner image of each color on the recording medium is shifted, the quality of the color image is deteriorated.

  In addition, since the image forming apparatus uses electrostatic force for image formation, various characteristics for image formation are likely to change due to environmental changes and temporal changes. For this reason, the density of the formed image tends to fluctuate. Such fluctuations in image density lead to a decrease in image quality.

  In order to suppress a decrease in image quality due to a positional shift and density fluctuation, the image forming apparatus normally has a function for adjusting image forming conditions. Such functions include, for example, image forming conditions automatically during print jobs such as paper registration adjustment (hereinafter referred to as “paper registration”) and paper process control (hereinafter referred to as “paper processing control”). A function for performing the adjustment is known. In the inter-sheet registration tone, for example, a pattern image (patch image) for adjustment is formed between sheets using each of a plurality of colors of toner, and the positional relationship between the formed patch images of the respective colors is confirmed. By adjusting the image formation timing of each color (registration adjustment), misalignment of the image of each color is prevented. In the inter-paper process controller, for example, a test patch image is formed between papers at a predetermined timing, and the image forming conditions are adjusted based on a value obtained by measuring the density of the patch image with a density sensor.

  As described above, the image forming conditions are generally adjusted by detecting the correction amount based on the patch image and reflecting the correction amount in the image forming conditions.

  Here, when the correction amount reflected in the image forming conditions is large, there is a large difference in image quality between pages before the correction amount is reflected and after the correction amount is reflected. If the difference in image quality is large, it will be noticeable, and users who use such printed materials will feel uncomfortable.

  With respect to such a problem, Patent Document 1 described later proposes an image forming apparatus that suppresses an excessive correction that is not necessary. The image forming apparatus of Patent Document 1 adjusts the color balance based on the exposure energy of light applied to the photosensitive drum when forming an electrostatic latent image and the development energy when developing the electrostatic latent image. The color balance is adjusted in advance by controlling one of the exposure energy and the development energy, and then detecting the density of the density detection pattern reflecting the control of the other to detect the other of the exposure energy and the development energy. Control. If the balance of exposure energy and development energy is fixed and the color balance is adjusted, correction may be more effective than necessary. Therefore, in Patent Document 1, the first density, which is the target value of the print density, is compared with the second density detected from the patch image, and the exposure energy and development are determined based on a predetermined density difference generation condition. Determine the order of energy control. Thereby, it is suppressed that correction | amendment becomes too effective more than necessary.

JP 2011-13397 A

  Although the image forming apparatus disclosed in Japanese Patent Laid-Open No. 2004-26883 can suppress the correction from being excessively necessary, if the required correction amount itself is large, there is a large difference in image quality between pages before and after the correction amount is reflected. Arise. For this reason, a sudden change in color may occur, and there is still room for improvement.

  The present invention has been made in order to solve the above-described problems, and one object of the present invention is to suppress a sudden change in color even when a correction amount is large, thereby reducing image quality. An image forming apparatus capable of suppressing the above problem is provided.

  In order to achieve the above object, an image forming apparatus according to one aspect of the present invention is an image forming apparatus capable of continuously forming images on a plurality of sheets. The image forming apparatus includes a correction amount detection unit for detecting a correction amount from an adjustment patch image and a continuous image formation on a plurality of sheets in order to adjust image forming conditions. A correction means for gradually increasing the correction amount from a correction amount smaller than the detected correction amount and reflecting the correction amount in the image forming conditions, and correcting the image forming conditions in stages, and the correction amount by the correcting means And image forming means for forming an image based on the image forming conditions in which is reflected.

  The correction amount is detected from the adjustment patch image, and the correction amount is gradually increased from the correction amount smaller than the detected correction amount, and the correction amount is reflected in the image forming condition, and the image forming condition is corrected step by step. . When forming images continuously on multiple sheets of paper, the correction amount is reflected in the image forming conditions while gradually increasing the correction amount, so the image quality is large before and after the correction amount is reflected. There is no difference. For this reason, even when the detected correction amount is large, it is possible to suppress a sudden change in color, so that the user who uses the printed material does not feel uncomfortable.

  Preferably, the image forming apparatus includes a threshold value storage unit for storing a predetermined correction amount value as a threshold value, and the correction amount detected by the correction amount detection unit is greater than the threshold value stored in the threshold value storage unit. And a correction amount determination unit for determining whether or not the image forming condition is corrected, and a unit for correcting the image forming condition based on the correction amount detected by the correction amount detection unit. In this case, it is preferable that the correction unit stepwise when the correction amount determination unit determines that the value of the correction amount detected by the correction amount detection unit is larger than the threshold value stored in the threshold value storage unit. The means for correcting and correcting the image forming conditions is determined by the correction amount determination means so that the value of the correction amount detected by the correction amount detection means is not larger than the threshold value stored in the threshold value storage means. In this case, the image forming condition is corrected based on the correction amount detected by the correction amount detecting means.

  If the detected correction amount is larger than the threshold value, the image forming conditions are corrected step by step. For example, if a correction amount value that would cause a large difference in image quality between pages before and after reflecting the correction amount is set as a threshold value, if the detected correction amount is larger than the threshold value, it is detected. If the correction amount is reflected on the image forming conditions at once, a large difference in image quality occurs before and after the correction amount is reflected. In such a case, abrupt color change can be easily suppressed by correcting the image forming conditions in stages. On the other hand, when the detected correction amount is equal to or less than the threshold value, even if the detected correction amount is reflected on the image forming conditions at once, there is no significant difference in image quality before and after the correction amount is reflected. In such a case, by correcting the image forming condition based on the detected correction amount, it is possible to easily suppress a decrease in image quality while suppressing a rapid change in color.

  More preferably, the correcting unit includes a unit for correcting the image forming condition step by step in units of pages.

  By correcting the image forming conditions step by step in units of pages, the correction amount can be reflected in the image forming conditions while suppressing a large change in image quality between pages.

  The correction unit may include a unit for correcting the image forming conditions in units of copies step by step.

  By correcting the image forming conditions step by step in units of copies, the correction amount can be reflected in the image forming conditions while suppressing a large change in image quality between copies. Pages included in the same part have the same image quality, and the correction amount can be reflected for each part. Usually, since printed materials are distributed in units of copies, users of printed materials are less likely to notice due to changes in image quality.

  More preferably, the correction unit gradually increases the correction amount from the correction amount smaller than the detected correction amount until the detected correction amount is reached, and reflects the correction amount in the image forming condition to gradually increase the image forming condition. Means for performing the correction. Thus, even when the detected correction amount is large, the large correction amount can be reflected in the image forming conditions without causing the user of the printed material to feel uncomfortable.

  More preferably, the image forming apparatus further includes a correction amount storage means for storing a predetermined correction amount value applied to one correction when the image forming conditions are corrected step by step. The means includes means for gradually increasing the correction amount while adding the predetermined correction amount stored in the correction amount storage means each time correction is performed, and correcting the image forming conditions in stages. Thereby, it is possible to easily correct the image forming conditions step by step.

  More preferably, the patch image is composed of a toner image printed on the transfer medium, and the correction amount detection means includes means for detecting the density correction amount based on the print density of the patch image. Thus, it is possible to easily correct the print density while suppressing a sudden change in color.

  More preferably, the image forming apparatus further includes a plurality of image forming units that form toner images of different colors on a transfer medium, the patch image is composed of toner images of different colors, and the correction amount detecting means is And means for detecting a positional deviation correction amount based on a positional deviation amount of patch images formed by the different image forming units. Thereby, it is possible to easily correct the positional deviation of the print image while suppressing the occurrence of a sudden color change.

  As described above, according to the present invention, even when the correction amount is large, it is possible to easily obtain an image forming apparatus capable of suppressing a rapid color change and suppressing a decrease in image quality.

1 is a diagram illustrating an overall configuration of an image forming apparatus according to a first embodiment of the present invention. FIG. 2 is a diagram showing a simplified configuration of an image forming unit. FIG. 2 is a control block diagram illustrating a hardware configuration of the image forming apparatus illustrated in FIG. 1. 2 is a flowchart showing a control structure of a program executed by the image forming apparatus of FIG. It is a detailed flow of step S1020 of FIG. FIG. 2 is a diagram for explaining image quality adjustment processing executed by the image forming apparatus in FIG. 1. FIG. 10 is a diagram for describing image quality adjustment processing that is executed by an image forming apparatus according to a modification of the first embodiment. 10 is a flowchart illustrating a control structure of a program executed by the image forming apparatus according to the second embodiment of the present invention. It is a detailed flow of step S2000 of FIG. FIG. 10 is a diagram for describing image quality adjustment processing executed by an image forming apparatus according to a second embodiment. 10 is a flowchart illustrating a control structure of a program executed by an image forming apparatus according to a third embodiment of the present invention. It is a detailed flow of step S3000 of FIG. FIG. 10 is a diagram for explaining image quality adjustment processing executed by an image forming apparatus according to a third embodiment. 10 is a flowchart illustrating a control structure of a program executed by an image forming apparatus according to a fourth embodiment of the present invention. It is a detailed flow of step S4010 of FIG. It is a detailed flow of step S4020 of FIG. It is a figure for demonstrating the image quality adjustment process performed with the image forming apparatus which concerns on 4th Embodiment.

  In the following embodiments, the same parts are denoted by the same reference numerals. Their functions and names are also the same. Therefore, detailed description thereof will not be repeated.

(First embodiment)
[overall structure]
Referring to FIG. 1, an image forming apparatus 100 according to the present embodiment is a tandem color image forming apparatus that includes four image forming units 22K, 22C, 22M, and 22Y.

  The first image forming unit 22K is an image forming unit for forming a black toner image, and the second image forming unit 22C is an image forming unit for forming a cyan toner image, and a third image. The forming unit 22M is an image forming unit for forming a magenta toner image, and the fourth image forming unit 22Y is an image forming unit for forming a yellow toner image. The detailed configuration of these image forming units 22K, 22C, 22M, and 22Y will be described later.

  Below the four image forming units 22K, 22C, 22M and 22Y, a laser scanner unit (hereinafter referred to as “LSU”) 24 is arranged. The LSU 24 includes a laser oscillation unit 26 including a semiconductor laser and an LSU control device 28 that controls the laser oscillation unit 26. The LSU control device 28 includes an ASIC (Application Specific Integrated Circuit) (not shown). The LSU 24 exposes the image forming units 22K, 22C, 22M, and 22Y by laser scanning according to the output image data signal.

  An endless transfer belt 30 is disposed above the four image forming units 22K, 22C, 22M, and 22Y. The transfer belt 30 is wound around two support rollers 32 provided at a distance from each other on the left and right sides, and rotates counterclockwise as indicated by an arrow R in FIG. As a material of the transfer belt 30, a material in which an appropriate amount of an electron conductive conductive material is contained in a resin such as polyimide or polyamide can be used. In the following description, with reference to the secondary transfer position in which the secondary transfer roller 34 that is paired with the one support roller 32 (on the right side in FIG. 1) is disposed with respect to the rotation direction of the transfer belt 30. Express upstream and downstream.

  From the upstream side to the downstream side in the rotation direction R of the transfer belt 30, the first image forming unit 22K for forming a black toner image, the second image forming unit 22C for forming a cyan toner image, and for forming a magenta toner image The third image forming unit 22M and the fourth image forming unit 22Y for forming a yellow toner image are arranged in this order.

  On the downstream side of the fourth image forming unit 22 </ b> Y, a detection device D <b> 1 for detecting a correction amount related to positional deviation from a patch image of a predetermined pattern formed on the transfer belt 30 is provided. The detection device D1 is disposed in the vicinity of the transfer belt 30.

  Above the transfer belt 30, there is provided a control device 36 including a computer including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The overall operation of the image forming apparatus 100 is controlled by the control device 36.

  The detection device D1 includes a semiconductor laser as a light emitting element, a condensing lens, and a photosensor (all not shown) as a light receiving element in the casing. The semiconductor laser generates laser light for reading the toner image on the transfer belt 30. The condensing lens narrows the light from the semiconductor laser onto the transfer belt 30. The photosensor includes a phototransistor or a photodiode, receives reflected light from the transfer belt 30, and outputs an electric signal corresponding to the amount of light to the control device 36. In the detection device D1, under the control of the control device 36, the laser light of the semiconductor laser is squeezed by the condensing lens, irradiated on the surface of the transfer belt 30, and the reflected light is received by the photosensor. The pattern interval of the toner image formed on the surface of the transfer belt 30 can be measured on the order of microns.

  Inside the transfer belt 30, a primary transfer roller 40 for transferring a single color toner image formed by the image forming units 22K, 22C, 22M, and 22Y onto the transfer belt 30 is provided to each of the image forming units 22K, 22C, and 22M. , 22Y, respectively. The single color toner images formed by the image forming units 22K, 22C, 22M, and 22Y are transferred so as to be superimposed on the transfer belt 30 to form one color image.

  The secondary transfer roller 34 described above, which transfers the color image formed on the transfer belt 30 to the sheet, on the downstream side in the rotation direction R of the transfer belt 30 from the fourth image forming unit 22Y that forms the yellow toner image. Is arranged. A belt cleaning unit 42 for cleaning the surface of the transfer belt 30 is provided downstream of the secondary transfer roller 34 in the rotation direction R of the transfer belt 30.

  The belt cleaning unit 42 includes a belt cleaning brush 44 and a belt cleaning blade 46 that are in contact with the transfer belt 30. The belt cleaning blade 46 is disposed downstream of the belt cleaning brush 44 in the rotation direction R of the transfer belt 30.

  Below the LSU 24, a tray 48 for storing paper is disposed. The sheets in the tray 48 are conveyed to a secondary transfer position where the secondary transfer roller 34 faces the transfer belt 30 by a plurality of sets (four sets in the present embodiment) of paper feed rollers 54. In FIG. 1, the sheet conveyance direction is indicated by an arrow P.

  On the downstream side of the secondary transfer roller 34 in the paper conveyance direction P, a fixing unit 50 for fixing the color image transferred onto the paper on the paper is provided. A paper discharge roller 52 for discharging the paper on which the color image is fixed from the color image forming apparatus 100 is provided further downstream of the fixing unit 50 in the paper transport direction P.

  In the color image forming apparatus 100 having the above-described configuration, the single color toner images formed by the image forming units 22K, 22C, 22M, and 22Y are sequentially transferred onto the transfer belt 30 and are then transferred onto the transfer belt 30. An image is formed. The color image on the transfer belt 30 is secondarily transferred onto a sheet conveyed by a plurality of pairs of paper feed rollers 54 at a secondary transfer position, and then fixed on the sheet by a fixing unit 50. The paper on which the color image is fixed is discharged from the color image forming apparatus 100 by the paper discharge roller 52. On the other hand, after the secondary transfer, the toner remaining on the transfer belt 30 without being transferred to the paper is removed by the belt cleaning unit 42.

  The image forming apparatus 100 also has a function (image quality adjustment function) for adjusting (correcting) image forming conditions such as paper registration and tone control.

  The inter-sheet registration tone is a function for correcting a positional deviation of the printing position. In the inter-sheet registration tone, a patch image of a predetermined pattern is formed on the transfer belt 30 by each of the image forming units 22K, 22C, 22M, and 22Y, and the pattern interval of each color is read by the detection device D1. The amount of misalignment (correction amount) of the printing position between each color is detected from the read pattern interval, and the image quality is adjusted (position misalignment adjustment) by reflecting the detected amount of correction in the image forming conditions.

  The paper spacing process control is a function for adjusting the printing density. In each of the image forming units 22K, 22C, 22M, and 22Y, a detection device D2 (see FIG. 3) including a density sensor is disposed in the vicinity of a later-described photosensitive drum and in the vicinity of the transfer belt 30. In the inter-sheet process controller, a test patch image is formed by each of the image forming units 22K, 22C, 22M, and 22Y, and is detected by a detection device D2 (density sensor) disposed in the vicinity of each photosensitive drum and in the vicinity of the transfer belt 30. Then, the print density of the patch image on the photosensitive drum and the patch image on the transfer belt 30 are read, and the correction amount is detected based on the read print density. Image quality adjustment (density adjustment) is performed by reflecting the detected correction amount in the image forming conditions. Specifically, the print density is adjusted by adjusting the developing bias voltage value, the charging potential setting value, the laser power, and the like based on the detected correction amount.

  In the inter-sheet registration tone and the inter-sheet process control, patch images are formed between sheets at a predetermined timing in a print job, and image forming conditions are adjusted.

  In the following description, the image forming units 22K, 22C, 22M, and 22Y are collectively referred to as “image forming unit 22”.

[Configuration of image forming unit]
Referring to FIG. 2, image forming unit 22 includes a photosensitive drum 60. Around the photosensitive drum 60, a charger 62 for charging the photosensitive drum 60, a developing device 64 for visualizing an electrostatic latent image on the photosensitive drum 60, and the photosensitive drum 60 remain after the primary transfer. A photosensitive drum cleaner 66 that removes toner-containing residues is arranged in this order along the rotational direction Rd of the photosensitive drum 60.

  The charger 62 performs corona discharge on the photosensitive drum 60 to charge the photosensitive drum 60 to a predetermined potential. On the outer peripheral surface of the photosensitive drum 60 charged to a predetermined potential by the charger 62, exposure by laser scanning from the LSU 24 is performed to form an electrostatic latent image.

  The developing device 64 includes a developing tank 68 in which a two-component developer is accommodated, and the developing tank 68 is provided with an opening 70 at a position facing the outer peripheral surface of the photosensitive drum 60. A developing roller 72 and a regulating blade 74 are provided in the developing tank 68 at a position facing the opening 70.

  The developing roller 72 carries the developer on its outer peripheral surface and transports it to supply the two-component developer to the photosensitive drum 60 to develop the electrostatic latent image. The developing roller 72 is disposed with a predetermined gap with respect to the outer peripheral surface of the photosensitive drum 60.

  The regulating blade 74 is a member for regulating the layer thickness of the two-component developer carried and conveyed on the surface of the developing roller 72, and is disposed with a predetermined gap with respect to the surface of the developing roller 72. Yes.

  The two-component developer accommodated in the developing tank 68 is agitated by the agitator 76. The agitator 76 is rotatably supported in the developing tank 68.

  The photosensitive drum cleaner 66 includes a cleaning blade 78, a cleaner housing 80, and a seal 82. The cleaning blade 78 is arranged so that its edge portion 84 is pressed against the surface (outer peripheral surface) of the photosensitive drum 60 in a direction opposite to the rotation direction Rd of the photosensitive drum 60, so that the edge portion 84 is exposed to light. It is a member for scraping off the residue on the surface of the body drum 60. The cleaning blade 78 is disposed in the cleaner housing 80 so that the edge portion 84 thereof is pressed against the rotation direction Rd of the photosensitive drum 60 at a position where the rotation direction of the photosensitive drum 60 is downward. Is arranged.

[Hardware configuration]
With reference to FIG. 2, the control device 36 is substantially a computer as described above, and controls the entire image forming apparatus 100. A common BUS line 150 extends from the control device 36. A storage unit 110, an image forming unit 120, an LSU control device 28, a detection device D 1, a detection device D 2, and an environment detection unit 130 are connected to the BUS line 150.

  The CPU of the control device 36 performs various controls according to a program for realizing the image forming process of the present embodiment. A program executed by the CPU is stored in the ROM or the storage unit 110 in the control device 36.

  The program stored in the ROM or the storage unit 110 of the control device 36 is read from the ROM or the storage unit 110 at the time of execution, stored in the RAM in the control device 36, and is stored in a CPU register called a program counter. It is read from the address in the indicated RAM, and is interpreted and executed by the CPU. Data necessary for execution is read from an address specified by an instruction in the register, RAM or storage unit 110 in the CPU. Similarly to this, the result of the execution is also stored at the address specified by the above-mentioned register in the CPU, the RAM, or the instruction of the storage unit 110.

  Further, the common BUS line 150 has an interface with a network line 106 such as a LAN (Local Area Network) line connected to another device using an application program such as a personal computer (PC), a word processor, and a graphic drawing tool. An NIC (Network Interface Card) 108 is also connected. The CPU of the control device 36 controls the storage unit 110, the detection device D1, the detection device D2, the LSU control device 28, the environment detection unit 130, the image forming units 22K, 22C, 22M, and 22Y, and the NIC 108 to input images. A desired operation such as image output and communication with other devices is executed, and data is stored in or read from the RAM or storage unit 110 of the control device 36 and the LSU control device 28.

  The image forming program according to the present embodiment is transmitted from an external device to the control device 36 via the network line 106 and the NIC 108 and stored in the internal RAM or the storage unit 110.

  The storage unit 110 includes, for example, an HDD (Hard Disk Drive). The storage unit 110 stores a computer program for realizing general operations of the image forming apparatus 100. The storage unit 110 also stores image data received by the image forming apparatus 100. The storage unit 110 further includes a data recording area 112 for recording various data in the image forming apparatus 100, a correction value storage unit 114 that stores a value of a predetermined correction amount applied when correcting the image forming conditions, and a predetermined value. A threshold value storage unit 116 that stores the value of the corrected amount as a threshold value is included. The data recording area 112 includes, for example, a first recording area 112a for recording the cumulative number of printed sheets, a second recording area 112b for recording an average printing ratio, a third recording area 112c for recording a reference printing ratio, and a photosensitive drum. A fourth recording area 112d for recording the traveling distance of the recording medium, and a fifth recording area 112e for recording the traveling distance of the transfer belt 30. The correction value storage unit 114 stores a predetermined correction amount value smaller than the threshold value, which is applied at the time of each of the positional deviation correction and the density correction. The threshold value stored in the threshold value storage unit 116 is a value serving as a reference when determining whether or not the detected correction amount is large. For example, when the detected correction amount is reflected in the image forming condition, the threshold value is a value of a correction amount that may cause a large difference in image quality before and after the correction amount is reflected. Note that the value of the correction amount stored in the correction value storage unit 114 and the value of the threshold value stored in the threshold value storage unit 116 can be appropriately changed by a user's setting change operation.

  In the present embodiment, the detected correction amount is not reflected on the image forming condition at once, but the correction amount is gradually reflected on the image forming condition while gradually increasing the correction amount. The correction value storage unit 114 stores a correction amount value to be applied to one correction, and the correction amount is gradually increased by adding the correction amount.

  The LSU control device 28 is constituted by a computer including a CPU, a ROM, a RAM, and the like, and has a laser exposure control function. The LSU control device 28 includes an image quality adjustment unit 160 that forms a patch image and adjusts image formation conditions such as a paper interval registration tone and a paper interval process control.

  The image forming unit 120 prints an image indicated by image data on a sheet. In addition to the image forming unit 22 and the transfer belt 30, the image forming unit 120 conveys the sheet. And a counter 126 that counts the number of rotations or the number of printed sheets of the photosensitive drum.

  The environment detection unit 130 detects the usage environment of the image forming apparatus 100 and includes, for example, a temperature sensor that detects temperature, a humidity sensor that detects humidity, and the like.

  The CPU of the control device 36 forms the patch image at a predetermined timing based on the usage environment such as temperature and humidity detected by the environment detection unit 130, the number of printed sheets counted by the counter 126, and the like. When the patch image is formed, the correction amount is detected from the patch image as described above.

Software configuration
With reference to FIGS. 4 and 5, a control structure of a computer program executed in the image forming apparatus 100 in order to perform image quality adjustment during a print job will be described. This program is activated when a print job execution instruction is received. Since both the positional deviation correction and the density correction are executed in the same manner, the positional deviation correction and the density correction will be described below simply as the correction of the image forming condition without distinguishing between the positional deviation correction and the density correction. In the following, “increasing the correction amount” means increasing in absolute value.

  Referring to FIG. 4, this program is executed after step S1000 for starting a print job and after step S1000, determines whether or not a correction amount is detected based on the patch image, and controls according to the determination result. Step S1010 for branching the flow of steps S1020, Step S1020 for adjusting the image quality by adjusting the image forming conditions when it is determined that the correction amount is detected in Step S1010, Step S1020 and after Step S1020 Step S1030 is executed when it is determined in S1010 that the correction amount has not been detected, and it is determined whether or not the print job has ended, and the flow of control is branched according to the determination result. If it is determined in step S1030 that the print job has not ended, control returns to step S1010. If it is determined in step S1030 that the print job has ended, the program ends.

  FIG. 5 is a detailed flow of step S1020 of FIG. Referring to FIG. 5, this routine refers to the threshold value stored in threshold value storage unit 116 to determine whether or not the detected correction amount is larger than the threshold value, and the flow of control is determined according to the determination result. In step S1100 to be branched and in step S1100, if it is determined that the detected correction amount is larger than the threshold value, step S1110 for initializing the variable n (n = 1) and step S1110 are executed after step S1110. Step S1120 for setting the correction amount obtained by multiplying the value of the correction amount stored in the storage unit 114 by the variable n as a correction amount for reflecting in the image forming conditions, and the step S1120 are executed after the step S1120. Step S1130 for correcting the image forming conditions by reflecting the conditions, executed after Step S1130, and the corrected image forming conditions are 1 Step S1140 for printing a page, and a step executed after step S1140 to determine whether or not the set correction amount is greater than or equal to the detected correction amount, and to branch the control flow according to the determination result S1150.

  This routine further includes step S1160 in which, when it is determined in step S1150 that the set correction amount is not equal to or greater than the detected correction amount, the correction amount is increased (n = n + 1) and control is returned to step S1120. When it is determined in step S1100 that the detected correction amount is equal to or less than the threshold value, step S1170 for setting the detected correction amount as a correction amount to be applied when correcting the image forming condition, after step S1170, and This is executed when it is determined in step S1150 that the set correction amount is equal to or larger than the detected correction amount, and the correction is executed by reflecting the set correction amount in the image forming conditions, and this routine is terminated. Step S1180. In step S1160, the correction amount is increased by adding the correction amount value stored in the correction value storage unit 114 to the set correction amount.

[Operation]
With reference to FIGS. 4 to 6, the operation of the image forming apparatus 100 according to the present embodiment based on the above-described structure and flowchart will be described.

  When a print instruction is given by the user, a print job is executed (step S1000 shown in FIG. 4). The image forming apparatus 100 forms a patch image at a predetermined timing on the basis of the usage environment such as temperature and humidity detected by the environment detection unit 130, the number of printed sheets counted by the counter 126, and the like. And image quality adjustment such as a paper interval control computer.

  When the patch image is formed, the image forming apparatus 100 detects the correction amount by reading the formed patch image. When the correction amount is detected (YES in step S1010), the image forming apparatus 100 refers to the threshold value stored in the threshold value storage unit 116 and determines whether or not the detected correction amount is larger than the threshold value (step S1010). Step S1100 shown in FIG. This threshold value is a value of a correction amount that will cause a large difference in image quality before and after the correction amount is reflected when the detected correction amount is reflected in the image forming conditions. For this reason, when the detected correction amount is larger than the threshold value, if the correction amount is reflected in the image forming conditions, the difference in image quality between pages increases and a rapid color change occurs.

  In order to eliminate such an inconvenience, when the detected correction amount is larger than the threshold value, the image forming apparatus 100 gradually increases the correction amount from the correction amount smaller than the threshold value and gradually reflects the correction amount in the image forming conditions. I will let you. Specifically, the correction value stored in the correction value storage unit 114 is referred to, and the correction value having the same value is set as a correction value to be reflected in the image forming conditions (step S1120). Then, the image forming condition is corrected with the correction amount (step S1130), and one page is printed with the corrected image forming condition (step S1140).

  Next, the image forming apparatus 100 determines whether or not the set correction amount is equal to or greater than the detected correction amount (step S1150). Since the initially set correction amount is smaller than the detected correction amount, it is determined here that the correction amount is not equal to or greater than the detected correction amount (NO in step S1150).

  Subsequently, the image forming apparatus 100 increases the correction amount by adding the correction amount value stored in the correction value storage unit 114 to the set correction amount (step S1160). In this case, the correction amount is twice the correction amount value stored in the correction value storage unit 114. Then, the image forming apparatus 100 newly sets the increased correction amount as a correction amount that reflects the image forming conditions (step S1120). The image forming conditions are corrected with the newly set correction amount (step S1130), and the next page is printed (step S1140). The image forming apparatus 100 repeats the above operation until the set correction amount becomes equal to or greater than the detected correction amount. If the set correction amount is equal to or greater than the detected correction amount (YES in step S1150), the correction amount is reflected in the image forming conditions, image quality adjustment is performed, and the remaining pages are printed. When a new correction amount is set, the newly set correction amount becomes the set correction amount.

  Referring to FIG. 6, when the detected correction amount is larger than the threshold value, image forming apparatus 100 reflects the correction amount in the image forming condition while gradually increasing the correction amount from the correction amount smaller than the detected correction amount. The image forming conditions are corrected step by step. When the set correction amount reaches the detected correction amount, the increase in the correction amount stops, and the image forming conditions are corrected with substantially the same correction amount as the detected correction amount.

  On the other hand, when the detected correction amount is equal to or smaller than the threshold value (NO in step S1100 shown in FIG. 5), image forming apparatus 100 sets the detected correction amount as a correction amount that reflects the image forming conditions (step shown in FIG. 5). S1170). The image forming conditions are corrected with the set correction amount (step S1180), and the remaining pages are printed. In this case, the detected correction amount is reflected on the image forming conditions at a time.

[Effects of the present embodiment]
As is clear from the above description, the following effects can be obtained by using the image forming apparatus 100 according to the present embodiment.

  The correction amount is detected from the adjustment patch image, and the correction amount is gradually increased from the correction amount smaller than the detected correction amount, and the correction amount is reflected in the image forming condition, and the image forming condition is corrected step by step. . When forming images continuously on multiple sheets of paper, the correction amount is reflected in the image forming conditions while gradually increasing the correction amount. Therefore, before and after reflecting the correction amount, There is no big difference in image quality. For this reason, even when the detected correction amount is large, it is possible to suppress a sudden color change. Therefore, the user who uses the printed material does not feel uncomfortable.

  If the detected correction amount is larger than the threshold value, the image forming conditions are corrected step by step. If a correction amount value that will cause a large difference in image quality between pages before and after reflecting the correction amount is set as a threshold value, and the detected correction amount is larger than the threshold value, the detected correction value If the amount is reflected on the image forming conditions at once, a large difference in image quality occurs before and after the correction amount is reflected. In such a case, abrupt color change can be easily suppressed by correcting the image forming conditions in stages. On the other hand, when the detected correction amount is equal to or less than the threshold value, even if the detected correction amount is reflected on the image forming conditions at once, there is no significant difference in image quality before and after the correction amount is reflected. In such a case, by correcting the image forming condition based on the detected correction amount, it is possible to easily suppress a decrease in image quality while suppressing a rapid change in color.

  By correcting the image forming conditions step by step in units of pages, the correction amount can be reflected in the image forming conditions while suppressing a large change in image quality between pages.

  Here, in the conventional image forming apparatus, when the detected correction amount is larger than the threshold value, the correction amount having the same value as the threshold value is used only once instead of the detected correction amount in order to suppress a rapid color change. It was reflected in the image forming conditions. In this case, although the image quality can be prevented from changing abruptly before and after the correction amount is reflected, not all of the necessary correction amount can be reflected in the image forming conditions.

  On the other hand, in the present embodiment, the correction amount is gradually increased from the correction amount smaller than the detected correction amount until the detected correction amount is reached, and the correction amount is reflected in the image forming conditions, so that the image is stepwise. Since the forming conditions are corrected, even when the detected correction amount is large, the large correction amount can be reflected in the image forming conditions without causing the user of the printed matter to feel uncomfortable. Therefore, all of the necessary correction amount (target correction amount) can be reflected in the image forming conditions.

  In addition, in the present embodiment, the same correction amount as the detected correction amount can be reflected in the image forming conditions regardless of the threshold value, so that the threshold value can be reduced. Therefore, when the detected correction amount is equal to or less than the threshold value, even if the detected correction amount is reflected in the image forming conditions at once, there is a large difference in image quality before and after the correction amount is reflected. Can be prevented.

(Modification of the first embodiment)
When the correction amount is reflected in the image forming conditions step by step, the printing may end before the correction amount reflected in the image forming condition reaches the detected correction amount. That is, there may be a case where all the correction amounts cannot be reflected in one copy. In this modification, when printing a plurality of copies, if all the correction amounts cannot be reflected in one copy, the remaining correction amounts that cannot be reflected are reflected in the next copy. It is controlled to let you.

  Referring to FIG. 7A, when the detected correction amount is larger than the threshold value, the correction amount is gradually increased while gradually increasing the correction amount from the correction amount smaller than the threshold value, as in the first embodiment. This is reflected in the image forming conditions. When one set of printing is completed before the set correction amount reaches the detected correction amount, the remaining correction amount until the detected correction amount is reached, as shown in FIG. This is reflected in the printing of the part. That is, at the time of printing the next part, the correction amount is gradually reflected on the image forming conditions while gradually increasing the correction amount from the correction amount set at the time of printing the previous part. This operation is repeated until the set correction amount reaches the detected correction amount.

(Second Embodiment)
The image forming apparatus according to the present embodiment is different from the first embodiment in which the image forming conditions are corrected step by step in increments of pages. .

  The image forming apparatus according to the present embodiment has the same hardware configuration as the image forming apparatus 100 according to the first embodiment. However, the ROM or the program stored in the storage unit 110 of the control device 36 is different.

Software configuration
Referring to FIG. 8, in the image forming apparatus according to the present embodiment, each process except for the process in step S2000 is the same as each process executed by the computer program shown in FIG. In the present embodiment, step S2000 is included instead of step S1020 shown in FIG.

  FIG. 9 is a detailed flow of step S2000 of FIG. Referring to FIG. 9, in the image forming apparatus according to the present embodiment, each process except for the process in step S2100 is the same as each process executed by the computer program shown in FIG. Hereinafter, different parts will be described.

  Referring to FIG. 9, this routine is executed after step S1130, and includes step S2100 in which one copy (one portion) is printed under the corrected image forming conditions and the control proceeds to step S1150.

[Operation]
With reference to FIGS. 9 and 10, the operation of the image forming apparatus according to the present embodiment based on the above-described structure and flowchart will be described. Operations other than the operation of performing printing under the corrected image forming conditions are the same as those in the first embodiment. Therefore, detailed description of similar operations will not be repeated.

  When the detected correction amount is larger than the threshold value, the image forming apparatus gradually reflects the correction amount in the image forming condition while gradually increasing the correction amount from the correction amount smaller than the threshold value, as in the first embodiment. I will let you. When the image forming condition is corrected with the set correction amount, the image forming apparatus prints one part under the corrected image forming condition (step S2100 shown in FIG. 9).

[Effects of the present embodiment]
As is clear from the above description, the following effects can be obtained by using the image forming apparatus according to the present embodiment.

  By correcting the image forming conditions step by step in units of copies, the correction amount can be reflected in the image forming conditions while suppressing a large change in image quality between copies. Pages included in the same part have the same image quality, and the correction amount can be reflected for each part. Usually, since printed materials are distributed in units of copies, users of printed materials are less likely to notice due to changes in image quality.

(Third embodiment)
When the detected correction amount is larger than the threshold value, the image forming apparatus according to the present embodiment first reflects the correction amount having the same value as the threshold value in the image forming condition, and then calculates the correction amount from the correction amount having the same value as the threshold value. The correction amount is gradually reflected in the image forming conditions while gradually increasing.

  The image forming apparatus according to the present embodiment has the same hardware configuration as the image forming apparatus 100 according to the first embodiment. However, the ROM or the program stored in the storage unit 110 of the control device 36 is different.

Software configuration
Referring to FIG. 11, in the image forming apparatus according to the present embodiment, each process except for the process in step S3000 is the same as each process executed by the computer program shown in FIG. In the present embodiment, step S3000 is included instead of step S1020 shown in FIG.

  FIG. 12 is a detailed flow of step S3000 of FIG. Referring to FIG. 12, this routine refers to the threshold value stored in threshold value storage unit 116 to determine whether or not the detected correction amount is larger than the threshold value, and the flow of control is determined according to the determination result. In steps S3100 and S3100 for branching, if it is determined that the detected correction amount is larger than the threshold, steps S3110 for initializing the variable n (n = 0) and steps S3110 are executed after step S3110. A correction amount obtained by adding a correction amount obtained by multiplying the correction amount value stored in the correction value storage unit 114 to the correction amount by the variable n with respect to the correction amount having the same value as the value is set as a correction amount to be reflected in the image forming conditions. Step S3120, Step S3130 which is executed after Step S3120 and corrects the image forming condition by reflecting the set correction amount in the image forming condition. Step S3140 is executed after 3130 and one page is printed under the corrected image forming conditions, and after step S3140, the value of the correction amount stored in the correction value storage unit 114 is set to the set correction amount. And step S3150 for increasing the correction amount by adding (n = n + 1).

  This routine is further executed after step S3150, and is newly executed as a correction amount for reflecting the increased correction amount in the image forming conditions, and after step S3160, and the newly set correction amount is used for the image. Step S3170 for correcting the image forming condition by reflecting it in the forming condition, Step S3180 executed after Step S3170, printing one page (next page) under the corrected image forming condition, and executed after Step S3180 Step S3190 for determining whether or not the set correction amount is equal to or greater than the detected correction amount and branching the control flow according to the determination result. If it is determined in step S3190 that the set correction amount is not greater than or equal to the detected correction amount, control returns to step S3150.

  In this routine, when it is determined in step S3100 that the detected correction amount is equal to or less than the threshold value, the detected correction amount is set as a correction amount to be applied when correcting the image forming conditions. In steps S3200 and S3200, Thereafter, and when it is determined in step S3190 that the set correction amount is equal to or larger than the detected correction amount, the correction is executed by reflecting the set correction amount in the image forming conditions. And step S3210 to end the routine.

[Operation]
The operation of the image forming apparatus according to the present embodiment based on the above-described structure and flowchart will be described with reference to FIGS.

  When a print instruction is given by the user, a print job is executed (step S1000 shown in FIG. 11). The image forming apparatus forms a patch image at a predetermined timing based on the usage environment such as temperature and humidity detected by the environment detection unit 130, the number of printed sheets counted by the counter 126, and the like. Execute image quality adjustment such as a paper interval control computer.

  When the patch image is formed, the image forming apparatus detects the correction amount by reading the formed patch image. When the correction amount is detected (YES in step S1010), the image forming apparatus refers to the threshold value stored in the threshold value storage unit 116 and determines whether or not the detected correction amount is larger than the threshold value (FIG. Step S3100 shown in FIG.

  If the detected correction amount is larger than the threshold (YES in step S3100), the image forming apparatus gradually increases the correction amount from the correction amount having the same value as the threshold and gradually reflects the correction amount in the image forming conditions. Go. Specifically, referring to the threshold value stored in the threshold storage unit 116, the correction amount having the same value is set as the correction amount to be reflected in the image forming conditions (step S3120). Then, the image forming conditions are corrected with the correction amount (step S3130), and one page is printed with the corrected image forming conditions (step S3140).

  Next, the image forming apparatus increases the correction amount by adding the correction amount value stored in the correction value storage unit 114 to the set correction amount (step S3150). Then, the image forming conditions are corrected with the correction amount (step S3170), and the next page is printed with the corrected image forming conditions (step S3180).

  Subsequently, the image forming apparatus determines whether or not the set correction amount is equal to or larger than the detected correction amount (step S3190). If the set correction amount is smaller than the detected correction amount (NO in step S3190), the image forming apparatus adds the correction amount value stored in correction value storage unit 114 to the set correction amount. As a result, the correction amount is further increased (step S3150). Then, similarly to the above, the increased correction amount is newly set as a correction amount to be reflected in the image forming conditions (step S3160). The image forming conditions are corrected with the set correction amount (step S3170), and the next page is printed (step S3180). The image forming apparatus repeats the above operation until the set correction amount is equal to or greater than the detected correction amount.

  When the set correction amount is equal to or greater than the detected correction amount (YES in step S3190), the image forming apparatus reflects the correction amount in the image forming conditions, performs image quality adjustment, and prints the remaining pages. .

  Referring to FIG. 13, when the detected correction amount is larger than the threshold value, the correction amount is set as an image forming condition while gradually increasing the correction amount from a correction amount smaller than the detected correction amount (a correction amount having the same value as the threshold value). Reflecting this, the image forming conditions are corrected step by step. When the set correction amount reaches the detected correction amount, the increase in the correction amount stops, and the image forming conditions are corrected with substantially the same correction amount as the detected correction amount.

  On the other hand, when the detected correction amount is equal to or smaller than the threshold (NO in step S3100 shown in FIG. 12), the detected correction amount is set as a correction amount that reflects the image forming conditions (step S3200). The image forming apparatus corrects the image forming conditions with the set correction amount (step S3210), and prints the remaining pages. In this case, the detected correction amount is reflected on the image forming conditions at a time.

[Effects of the present embodiment]
As is clear from the above description, the following effects can be obtained by using the image forming apparatus according to the present embodiment.

  When the detected correction amount is larger than the threshold value, as described above, the correction amount is gradually increased from the correction amount having the same value as the threshold value, and the correction amount is reflected in the image forming condition, and the image forming condition is gradually increased. Make corrections. Therefore, it is easy to increase the correction amount up to the detected correction amount. Therefore, it is possible to easily reflect all the correction amounts in one copy.

(Fourth embodiment)
In the image forming apparatus according to the present embodiment, if the detected correction amount is larger than the threshold value and all of the correction amounts cannot be reflected in the print job, the remaining correction amounts that could not be reflected Is controlled to be reflected in the next print job. If all the correction amounts cannot be reflected in the print job, a correction amount smaller than the detected correction amount is stored as a set correction amount. When a correction amount smaller than the detected correction amount is stored, the correction amount storage flag is set to “1”. The correction amount storage flag is a flag indicating whether or not a correction amount smaller than the detected correction amount is stored at the end of the print job. When a correction amount smaller than the detected correction amount is stored at the end of the print job, the correction amount storage flag is set to “1”, and a correction amount greater than the detected correction amount is stored at the end of the print job The correction amount storage flag is set to “1”.

  The image forming apparatus according to the present embodiment has the same hardware configuration as the image forming apparatus 100 according to the first embodiment. However, the ROM or the program stored in the storage unit 110 of the control device 36 is different.

Software configuration
Referring to FIG. 14, in the image forming apparatus according to the present embodiment, each process except for the processes in steps S4000, S4010, S4020, and S4030 is the same as the processes executed by the computer program shown in FIG. It is the same. Hereinafter, different parts will be described.

  This program is executed after step S1000, and includes step S4000 which determines whether or not the correction amount storage flag is set to “1” and branches the control flow according to the determination result. If it is determined in step S4000 that the correction amount storage flag is not set to “1”, the control proceeds to step S1010.

  The program further performs step S4010 in which the first image quality adjustment is performed by adjusting the image forming conditions when it is determined in step S1010 that the correction amount has been detected. In step S4000, the correction amount storage flag is set to “ If it is determined that the correction amount is set to “1”, the correction amount is set in step S4020 in which the second image quality adjustment is performed by adjusting the image forming conditions, after step S4010 and step S4020, and in step S1010. Step S4030 that is executed when it is determined that the print job has not been detected, determines whether or not the print job has ended, and branches the control flow according to the determination result. If it is determined in step S4030 that the print job has not ended, control returns to step S4000. If it is determined in step S4030 that the print job has ended, the program ends.

  FIG. 15 is a detailed flow of step S4010 of FIG. Referring to FIG. 15, in the image forming apparatus according to the present embodiment, each process except for the processes in steps S4100 and S4110 is the same as each process executed by the computer program shown in FIG. Hereinafter, different parts will be described.

  When it is determined in step S1150 that the set correction amount is not equal to or greater than the detected correction amount, this routine determines whether or not the print job has ended, and the flow of control is determined according to the determination result. Step S4100 for branching and Step S4110 for setting the correction amount storage flag to “1” and ending this routine when it is determined in Step S4100 that the print job has ended. If it is determined in step S4100 that the print job has not ended, control proceeds to step S1160.

  FIG. 16 is a detailed flow of step S4020 of FIG. Referring to FIG. 16, this routine is executed after step S4200 for reading the set correction amount, and after step S4200, and the value of the correction amount stored in correction value storage unit 114 as the read correction amount. Step S4210 for increasing the correction amount by adding (n = n + 1).

  This routine is further executed after step S4210. Step S4220 is newly set as a correction amount that reflects the increased correction amount in the image forming conditions, and the routine is executed after step S4220. Step S4230 for correcting the image forming condition by reflecting it in the forming condition, Step S4240 executed after Step S4230, Step S4240 for printing one page under the corrected image forming condition, and Step S4240 executed and set. It is determined whether or not the correction amount being detected is equal to or greater than the detected correction amount, and step S4250 is made to branch the control flow according to the determination result.

  This routine further determines whether or not the print job is completed when it is determined in step S4250 that the set correction amount is not equal to or greater than the detected correction amount, and the flow of control according to the determination result. In step S4260 and step S4250, when it is determined that the set correction amount is greater than or equal to the detected correction amount, the correction amount storage flag is set to “0”, and this routine is ended. S4270. If it is determined in step S4260 that the print job has not ended, control returns to step S4210. If it is determined in step S4260 that the print job has ended, this routine ends.

[Operation]
With reference to FIGS. 14 to 17, the operation of the image forming apparatus according to the present embodiment based on the above-described structure and flowchart will be described.

  When the user gives a print instruction, a print job is executed (step S1000 shown in FIG. 14). When executing the print job, the image forming apparatus determines whether the correction amount storage flag is set to “1”. That is, it is determined whether all the detected correction amounts can be reflected in the previous print job. When the correction amount storage flag is set to “1” (YES in step S4000), it indicates that a correction amount smaller than the detected correction amount is stored, so that the detected correction amount during the previous print job is stored. It is determined that all of these could not be reflected. On the other hand, when the correction amount storage flag is set to “0” (NO in step S4000), it is detected during the previous print job to indicate that a correction amount greater than the detected correction amount is stored. It is determined that all the correction amounts have been reflected.

  The image forming apparatus forms a patch image at a predetermined timing based on the usage environment such as temperature and humidity detected by the environment detection unit 130, the number of printed sheets counted by the counter 126, and the like. Execute image quality adjustment such as a paper interval control computer.

  Referring to FIG. 17A, when the correction amount storage flag is set to “0” (NO in step S4000 shown in FIG. 14), the correction amount is detected (step shown in FIG. 14). In step S1010, YES, the image forming apparatus gradually increases the correction amount from the correction amount smaller than the detected correction amount and reflects the correction amount in the image forming conditions in a stepwise manner, as in the first embodiment. Then, the image forming conditions are corrected. When the print job ends before the set correction amount reaches the detected correction amount (YES in step S4100 shown in FIG. 15), the image forming apparatus sets the correction amount storage flag to “1” (FIG. 15). Step S4110 shown in FIG.

  Referring to FIG. 17B, when the correction amount storage flag is set to “1” (YES in step S4000 shown in FIG. 14), the set correction amount is read (step shown in FIG. 16). In step S4200, the correction amount is increased by adding the correction amount value stored in the correction value storage unit 114 to the read correction amount (step S4210 shown in FIG. 16). The image forming apparatus sets the increased correction amount as a correction amount that reflects the image forming conditions (step S4220 shown in FIG. 16). The image forming conditions are corrected with the set correction amount (step S4230 shown in FIG. 16), and one page is printed with the corrected image forming conditions (step S4240 shown in FIG. 16).

  Subsequently, the image forming apparatus determines whether or not the set correction amount is equal to or greater than the detected correction amount (step S4250). If the set correction amount is equal to or greater than the detected correction amount (YES in step S4250), the image forming apparatus sets the correction amount storage flag to “0” (step S4270). Then, image quality adjustment is performed by reflecting the set correction amount equal to or greater than the detected correction amount in the image forming conditions, and the remaining pages are printed. If the set correction amount is not equal to or greater than the detected correction amount (NO in step S4250), the correction amount is gradually reflected in the image forming conditions while gradually increasing the correction amount.

  When the correction amount storage flag is set to “0” and the detected correction amount is equal to or smaller than the threshold value, the image forming apparatus uses the detected correction amount as in the first embodiment. It is set as a correction amount to be reflected in the image forming conditions (step S1170 shown in FIG. 15). The image forming conditions are corrected with the set correction amount (step S1180 shown in FIG. 15), and the remaining pages are printed. In this case, the detected correction amount is reflected on the image forming conditions at a time.

[Effects of the present embodiment]
As is clear from the above description, the following effects can be obtained by using the image forming apparatus according to the present embodiment.

  If the detected correction amount is larger than the threshold value and all the correction amounts cannot be reflected in the print job, the remaining correction amounts that could not be reflected are reflected in the next print job. Also with this configuration, it is possible to suppress the deterioration of the image quality while suppressing a rapid color change.

[Modification]
In the above embodiment, an example in which the present invention is applied to a color image forming apparatus has been described. However, the present invention is not limited to such an embodiment. The present invention can also be applied to, for example, a monochrome image forming apparatus other than a color image forming apparatus.

  In the above-described embodiment, an example has been described in which a threshold value is set, and when the detected correction amount is larger than the threshold value, the correction amount is reflected step by step in the image forming condition. Is not limited. Regardless of whether or not the detected correction amount is larger than the threshold value, the correction amount may be reflected in the image forming conditions step by step. In that case, the threshold need not be set.

  In the above embodiment, when the correction amount is gradually reflected in the image forming conditions while gradually increasing the correction amount, the correction amount is gradually increased while being gradually increased to a linear shape (linear shape). Although an example in which the amount is reflected in the image forming conditions has been shown, the present invention is not limited to such an embodiment. For example, the correction amount may be gradually reflected in the image forming conditions while gradually increasing the correction amount in a non-linear manner.

  In the above-described embodiment, an example in which the value of a predetermined correction amount applied to one correction is stored in advance and the correction amount is gradually increased by adding the value of the correction amount has been described. The invention is not limited to such an embodiment. For example, when performing inter-sheet registration adjustment, inter-sheet process control, etc., a predetermined correction amount value applied to one correction is calculated from the remaining number of printed sheets, and the correction amount is gradually increased from the calculated correction amount. However, the correction amount may be reflected in the image forming conditions step by step.

  In the first embodiment, an example is shown in which the correction amount is increased for each page and the correction amount is reflected in the image forming conditions step by step. However, the present invention is limited to such an embodiment. Not. For example, the correction amount may be increased for each of a plurality of pages, and the correction amount may be reflected in the image forming conditions step by step.

  In the second embodiment, an example has been described in which the correction amount is increased for each copy, and the correction amount is reflected step by step in the image forming conditions. However, the present invention is limited to such an embodiment. Not. For example, the correction amount may be increased for each of a plurality of copies, and the correction amount may be reflected in the image forming conditions step by step.

  Embodiments obtained by appropriately combining the techniques disclosed above are also included in the technical scope of the present invention.

  The embodiment disclosed herein is merely an example, and the present invention is not limited to the embodiment described above. The scope of the present invention is indicated by each claim of the claims after taking into account the description of the detailed description of the invention, and all modifications within the meaning and scope equivalent to the wording described therein are included. Including.

22C, 22M, 22Y, 22K, 22 Image forming unit 26 Laser oscillator 28 LSU control device 30 Transfer belt 36 Control device 60 Photosensitive drum 100 Image forming device 110 Storage unit 114 Correction value storage unit 116 Threshold storage unit 120 Image forming unit 130 Environment Detection Unit 160 Image Quality Adjustment Unit D1, D2 Detection Device

Claims (8)

An image forming apparatus capable of continuously forming images on a plurality of sheets,
Correction amount detecting means for detecting a correction amount from the adjustment patch image in order to adjust the image forming conditions;
When forming an image continuously on a plurality of sheets, the correction amount is gradually increased from the correction amount smaller than the detected correction amount, and the correction amount is reflected in the image forming conditions, so that the image is stepwise. Correction means for correcting the forming conditions;
An image forming unit configured to form an image based on an image forming condition in which a correction amount is reflected by the correcting unit. Threshold storage means for storing a predetermined correction amount value as a threshold;
Correction amount determination means for determining whether or not the correction amount detected by the correction amount detection means is greater than a threshold value stored in the threshold value storage means;
Means for correcting the image forming condition based on the correction amount detected by the correction amount detection means,
When the correction amount determination unit determines that the correction amount value detected by the correction amount detection unit is greater than the threshold value stored in the threshold value storage unit, the correction unit performs image formation step by step. Correct the conditions,
The means for performing the correction is determined when the correction amount determination means determines that the value of the correction amount detected by the correction amount detection means is not greater than the threshold stored in the threshold storage means. The image forming apparatus according to claim 1, wherein the image forming condition is corrected based on a correction amount detected by the correction amount detecting unit.   The image forming apparatus according to claim 1, wherein the correcting unit includes a unit for correcting the image forming condition step by step in units of pages.   The image forming apparatus according to claim 1, wherein the correcting unit includes a unit for correcting the image forming conditions step by step in units of copies.   The correction means gradually corrects the correction amount from the correction amount smaller than the detected correction amount until the detected correction amount is reached, and reflects the correction amount in the image forming condition to gradually correct the image forming condition. The image forming apparatus according to claim 1, further comprising means for performing the steps. A correction amount storage means for storing a value of a predetermined correction amount to be applied to one correction when the image forming conditions are corrected stepwise;
The correction means includes means for gradually correcting the image forming condition by gradually increasing the correction amount while adding the predetermined correction amount stored in the correction amount storage means each time correction is performed. The image forming apparatus according to claim 1 or 2. The patch image consists of a toner image printed on a transfer medium,
The image forming apparatus according to claim 1, wherein the correction amount detection unit includes a unit for detecting a density correction amount based on a print density of the patch image. A plurality of image forming units for forming toner images of different colors on a transfer medium;
The patch image is composed of the toner images of different colors,
The correction amount detection unit includes a unit for detecting a positional shift correction amount based on a positional shift amount of the patch images formed between the different image forming units. The image forming apparatus described in 1.

Images