JP2008032926A - Image forming system and control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming system which optimumly performs the image adjustment of an image forming apparatus equipped with a post processor. <P>SOLUTION: An image forming processing to form an image is performed, and whether the image adjustment is necessary is judged. When it is judged that the image adjustment is necessary, the operating situation of the post processor 102 is confirmed, and when the post processor 102 is in operation, the image adjusting processing judged as the necessary processing is inhibited. When the operation of the post processor 102 is ended, the inhibition of the image adjusting processing is released, and the image adjusting processing judged as the necessary processing is started. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming system including an image forming apparatus that forms an image on a recording medium using an electrophotographic method, and a post-processing apparatus that performs post-processing of the recording medium discharged from the image forming apparatus, and control thereof. Regarding the method.

  As a conventional image forming system, there is an image forming apparatus including a post-processing device that performs post-processing such as stapling and punching. In such an image forming system, control of the image forming apparatus and control of stapling processing, punching processing, and the like in the post-processing apparatus are executed independently.

  Some of the conventional image forming apparatuses have an image adjustment function that stabilizes an image to be formed. As an image adjustment function, a toner pattern is formed on an image carrier such as an intermediate transfer belt, the formation position or density of the toner pattern is detected, and an image misregistration (registration misalignment) or image There is one that detects these density deviations and adjusts them (see, for example, Patent Document 1).

  Conventionally, relatively few image forming apparatuses having only a print function that does not have an image reading function such as a scanner can be connected to a post-processing apparatus. However, even in a small image forming apparatus, if the post-processing can be performed on the recording medium as necessary, the form of the recording medium that can be output is widened, and the usability is improved. For this reason, it is considered that various uses will increase in the future for small image forming apparatuses to which a post-processing apparatus can be connected.

However, in the image forming apparatus having the conventional post-processing apparatus as described above, the vibration during the stapling operation of the post-processing unit, for example, the staple unit is transmitted to the image reading unit, and the image reading unit is shaken by the vibration to read the image. There was a problem of deterioration. In order to prevent the deterioration of the read image, an image forming apparatus that interrupts reading of a document image while the post-processing apparatus is executing post-processing has been proposed (for example, see Patent Document 2). As a result, reading of the image reading unit is interrupted during post-processing by the post-processing device, so that vibration during the stapling operation is transmitted to the image reading unit, and deterioration of the read image due to shaking of the image reading unit due to vibration is prevented. be able to.
Japanese Patent Laid-Open No. 2002-72574 Japanese Patent Laid-Open No. 2005-79613

  However, in the conventional image forming apparatus, when an image adjustment toner pattern (patch) is formed on the image carrier during the post-processing operation of the post-processing apparatus, patch formation unevenness (positional deviation) and density unevenness occur. End up. When image adjustment is performed by detecting a patch in which such formation unevenness or density unevenness occurs, image adjustment cannot be performed with high accuracy. In particular, when the patch detection unit is provided on the recording medium discharge side in the image forming apparatus, if the detection unit detects a patch during the post-processing operation, the detection unit is accurate because of the influence of vibration due to the post-processing operation. The patch cannot be detected. For this reason, an optimal image adjustment value cannot be obtained, and an unstable image is formed.

  The phenomenon as described above appears more prominently in a small image forming apparatus equipped with a post-processing device.

  As described above, in the conventional image forming apparatus, optimal image adjustment cannot be performed, and a stable optimal image may not be formed.

  An object of the present invention is to provide an image forming system including an image forming apparatus and a post-processing apparatus that can optimally perform image adjustment, and a control method thereof.

  In order to achieve the above object, the image forming system according to claim 1 includes an image forming apparatus having an image forming means for transferring a toner image developed on an image carrier to a recording medium based on image information; In an image forming system comprising a post-processing device for post-processing the recording medium discharged from a forming device, a toner pattern forming means for forming a measurement toner pattern on the image carrier, and the image carrier A reading unit that reads the measurement toner pattern formed above, a determination unit that determines whether or not to adjust an image forming condition of the image forming unit, a determination unit that determines that the image forming condition is adjusted; And prohibiting the formation of the measurement toner pattern or reading of the measurement toner pattern when the post-processing device is executing the post-processing. And having a stage.

  8. The image forming system control method according to claim 7, further comprising: an image forming apparatus having an image forming unit that transfers a toner image developed on an image carrier to a recording medium based on image information; and a paper discharge from the image forming apparatus. In a control method of an image forming system having a post-processing device for performing post-processing of the recorded medium, a toner pattern forming step for forming a measurement toner pattern on the image carrier, and a toner pattern forming step formed on the image carrier. A reading step for reading the measured toner pattern, a determining step for determining whether or not to adjust the image forming condition of the image forming unit, a determination that the image forming condition is adjusted in the determining step, and the post-processing When the apparatus is performing the post-processing, the measurement toner pattern forming step or the measurement toner pattern reading is performed. And inhibits the step.

  According to the present invention, when the image forming condition of the image forming unit is determined to be adjusted and the post-processing unit is performing post-processing, it is prohibited to form the measurement toner pattern on the image carrier. The measurement toner pattern is not formed during the post-processing. Therefore, it is possible to prevent formation unevenness and density unevenness from occurring in the measurement toner pattern, and the image forming conditions of the image forming unit are adjusted based on the measurement toner pattern formed during the post-processing. This can be prevented. Therefore, it is possible to prevent the image adjustment by detecting the measurement toner pattern in which the formation unevenness or the density unevenness has occurred, and the image adjustment of the image forming unit can be optimally performed. Thereby, a desired optimum image can be stably formed.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, the image forming system 100 according to the first embodiment of the present invention will be described.

  FIG. 1 is a cross-sectional view showing a schematic configuration of an image forming system 100 according to the first embodiment of the present invention.

  As shown in FIG. 1, the image forming system 100 includes an image forming apparatus 101 and a post-processing apparatus 102.

  First, the image forming apparatus 101 will be described. FIG. 2 is a cross-sectional view illustrating a schematic configuration of the image forming apparatus 101.

  The image forming apparatus 101 is a small full-color printer that does not include an image reading unit, and includes an image forming unit 1 having four image forming units 1Y, 1M, 1C, and 1Bk as shown in FIG. ing. The image forming unit 1Y is an image forming unit that forms a yellow image, and the image forming unit 1M is an image forming unit that forms a magenta image. The image forming unit 1C is an image forming unit that forms a cyan image, and the image forming unit 1Bk is an image forming unit that forms a black image. These four image forming units 1Y, 1M, 1C, and 1Bk are arranged in a line at a predetermined interval on a straight line that is inclined obliquely downward and rearward.

  Each of the image forming units 1Y, 1M, 1C, and 1Bk is provided with drum-type electrophotographic photosensitive members (hereinafter referred to as photosensitive drums) 2a, 2b, 2c, and 2d as image carriers. Around each photosensitive drum 2a, 2b, 2c, 2d, there are primary chargers 3a, 3b, 3c, 3d, developing devices 4a, 4b, 4c, 4d, transfer rollers 5a, 5b, 5c, 5d as transfer means, The drum cleaners 6a, 6b, 6c, and 6d are disposed, respectively. A laser exposure unit 7 is installed below the primary chargers 3a, 3b, 3c, 3d and the developing units 4a, 4b, 4c, 4d.

  Each developing unit 4a, 4b, 4c, 4d contains yellow toner, cyan toner, magenta toner, and black toner, respectively.

  Each of the photosensitive drums 2a, 2b, 2c, and 2d is a negatively charged OPC photosensitive member, has a photoconductive layer on the surface of an aluminum drum base, and is driven in a direction indicated by an arrow (not shown) by a driving device (not shown). 2 in a clockwise direction) at a predetermined process speed.

  Primary chargers 3a, 3b, 3c, and 3d as primary charging means bring the surface of each photosensitive drum 2a, 2b, 2c, and 2d to a predetermined negative potential by a charging bias applied from a charging bias power source (not shown). Charge uniformly.

  The developing devices 4a, 4b, 4c, and 4d contain toner, and are developed as toner images by attaching toners of colors corresponding to the electrostatic latent images formed on the photosensitive drums 2a, 2b, 2c, and 2d, respectively. Visualization).

  Transfer rollers 5a, 5b, 5c and 5d as primary transfer means are disposed so as to be able to contact the photosensitive drums 2a, 2b, 2c and 2d via the intermediate transfer belt 8 in the primary transfer portions 32a, 32b, 32c and 32d, respectively. Has been.

  The drum cleaners 6a, 6b, 6c, and 6d are cleaning blades and the like for removing residual transfer toner remaining on the photosensitive drums 2a, 2b, 2c, and 2d from the photosensitive drums 2a, 2b, 2c and 2d, respectively. have.

  The intermediate transfer belt 8 is disposed above the photosensitive drums 2 a, 2 b, 2 c, and 2 d and is stretched between the secondary transfer counter roller 10 and the tension roller 11. The secondary transfer counter roller 10 is disposed in the secondary transfer portion 34 so as to be in contact with the secondary transfer roller 12 via the intermediate transfer belt 8. The intermediate transfer belt 8 is made of a dielectric resin such as a polycarbonate, a polyethylene terephthalate resin film, or a polyvinylidene fluoride resin film.

  Further, the intermediate transfer belt 8 is inclined so that the primary transfer surface 8b formed on the surface facing the photosensitive drums 2a, 2b, 2c, 2d is inclined with the secondary transfer roller 12 side downward. .

  As described above, the intermediate transfer belt 8 is disposed to face the photosensitive drums 2a, 2b, 2c, and 2d so as to be movable on a plane that is in contact with the upper surfaces of the photosensitive drums 2a, 2b, 2c, and 2d. Therefore, in the intermediate transfer belt 8, a primary transfer surface 8b that is a surface facing the photosensitive drums 2a, 2b, 2c, and 2d is inclined so that the secondary transfer portion 34 side is downward. Specifically, the inclination angle of the primary transfer surface 8b is set to about 15 °. Further, the intermediate transfer belt 8 is disposed on the secondary transfer unit 34 side to apply a driving force to the intermediate transfer belt 8, and the secondary transfer counter roller 10 and the primary transfer units 32a to 32a. It is stretched by two tension rollers 11 that are arranged on the opposite side across 32d and apply tension to the intermediate transfer belt 8.

  The secondary transfer counter roller 10 is disposed so as to be in contact with the secondary transfer roller 12 via the intermediate transfer belt 8 at the secondary transfer unit 34. A belt cleaning unit (not shown) for removing and collecting the residual toner remaining on the surface of the intermediate transfer belt 8 is installed outside the endless intermediate transfer belt 8 and in the vicinity of the tension roller 11. Yes. A fixing device 16 having a fixing roller 16a and a pressure roller 16b has a vertical path configuration on the downstream side (upward in FIG. 2) of the transfer material (recording medium) P with respect to the secondary transfer unit 34. is set up.

  The exposure unit 7 includes laser light emitting means that emits light corresponding to time-series electric digital pixel signals of input image information, a polygon lens, a reflection mirror, and the like. The exposure device 7 exposes the photosensitive drums 2a, 2b, 2c, and 2d so that images are formed on the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d charged by the primary chargers 3a, 3b, 3c, and 3d, respectively. An electrostatic latent image of each color corresponding to the information is formed.

  The image forming apparatus 101 includes a transport unit 50 that transports the transfer material P from the paper feed cassette 17 or the manual feed tray 20 as illustrated in FIG.

  Next, an image forming operation by the image forming apparatus 101 described above will be described.

  When an image formation start signal is issued, the photosensitive drums 2a, 2b, 2c, 2d are driven to rotate at a predetermined process speed in the image forming units 1Y, 1M, 1C, 1Bk, and primary chargers 3a, 3b, 3c. , 3d are uniformly charged negatively. The exposure unit 7 irradiates an externally input color-separated image signal from the laser light emitting element, and passes each color on each photosensitive drum 2a, 2b, 2c, 2d via a polygon lens, a reflection mirror, and the like. An electrostatic latent image is formed.

  First, the electrostatic latent image formed on the photosensitive drum 2a is attached with yellow toner by the developing device 4a to which a developing bias having the same polarity as the charging polarity (negative polarity) of the photosensitive drum 2a is applied. As a visible image. This yellow toner image is driven by a transfer roller 5a to which a primary transfer bias (a reverse polarity (positive polarity) to toner) is applied in a primary transfer portion 32a between the photosensitive drum 2a and the transfer roller 5a. Primary transfer is performed on the intermediate transfer belt 8.

  The intermediate transfer belt 8 onto which the yellow toner image has been transferred is moved in the direction of the image forming unit 1M. In the image forming unit 1M, the magenta toner image formed on the photosensitive drum 2b is transferred by the primary transfer unit 32b in the same manner as the operation in the image forming unit 1Y described above, and is transferred onto the intermediate transfer belt 8. Overlaid on the yellow toner image.

  The intermediate transfer belt 8 onto which the magenta toner image has been transferred is moved in the direction of the image forming unit 1C. Similarly, cyan and black toner images formed on the photosensitive drums 2c and 2d in the image forming units 1C and 1Bk are primary on the yellow and magenta toner images superimposed and transferred on the intermediate transfer belt 8. The images are sequentially overlapped at the transfer portions 32c and 32d. As a result, a full-color toner image is formed on the intermediate transfer belt 8.

  As described above, when the toner image is transferred to the intermediate transfer belt 8 in each image forming unit, the transfer residual toner remaining on the photosensitive drums 2a, 2b, 2c, and 2d is drum cleaners 6a, 6b, and 6c. , 6d are scraped off and collected by a cleaner blade or the like.

  Then, the transfer material P fed from the paper feed cassette 17 or the manual feed tray 20 through the transport path 18 has the full-color toner image on the intermediate transfer belt 8 at the leading edge of the secondary transfer counter roller 10 and the secondary transfer roller 12. Is conveyed to the secondary transfer unit 34 by the registration roller 19 in synchronization with the timing of reaching the secondary transfer unit 34 between the two. Then, the full-color toner image is collectively transferred onto the transfer material P conveyed to the secondary transfer unit 34 by the secondary transfer roller 12 to which a secondary transfer bias (opposite polarity (positive polarity) to the toner) is applied. Next transferred.

  The transfer material P on which the full-color toner image is formed is conveyed to the fixing device 16 and is conveyed to the fixing nip portion between the fixing roller 16a and the pressure roller 16b, and is heated and pressed in the fixing nip portion. It is thermally fixed on the surface of the transfer material P. Then, the transfer material P on which the full-color toner image is fixed is discharged onto a paper discharge tray 22 formed on the upper surface of the image forming apparatus 101 by a paper discharge roller 21. A series of image forming operations in the image forming apparatus 101 ends. Incidentally, secondary transfer residual toner or the like remaining on the intermediate transfer belt 8 is removed and collected by a belt cleaning unit (not shown).

  The above is the image forming operation at the time of single-sided image formation in the image forming apparatus 101. At the time of double-sided image formation, the transfer material P on which the toner image is formed on one side as described above is not discharged onto the paper discharge tray 22, and the transfer material P is reversed in the paper supply unit 50, and the secondary transfer unit. 34, and a toner image is transferred and discharged onto the paper discharge tray 22 in the same manner as in the case of forming the one-sided image.

  Next, the post-processing device 102 will be described.

  As shown in FIG. 1, the post-processing device 102 is discharged from the post-processing unit 103 and the post-processing unit 103 that performs post-processing on the recording paper (transfer material P) discharged from the image forming apparatus 101. And a paper discharge tray 104 on which the recording paper is placed. Regardless of whether or not post-processing is performed in the post-processing unit 103, the recording paper is discharged to the paper discharge tray 104.

  The post-processing unit 103 performs, for example, stapling, punching, and folding as post-processing. In the stapling process, the post-processing unit 103 bundles and aligns the recording sheets discharged from the image forming apparatus 101, and performs a stapling operation that stops a predetermined position of the aligned recording sheets. Specifically, the post-processing unit 103 aligns the recording paper bundle in order to staple to an accurate position, and a predetermined stapling position of the aligned recording paper bundle, for example, any one of the upper and lower corners or The staple unit is moved to two places in the main scanning direction to be bound.

  Further, the post-processing unit 103 bundles and aligns the recording sheets discharged from the image forming apparatus 101 in the punching process, and two or more predetermined punch positions of the aligned recording sheet bundle, for example, in the main scanning direction or Punching is performed to make holes in three places.

  In the folding control, the post-processing device 103 performs a folding operation for folding the recording paper bundle on which the staple processing has been performed into a predetermined form, for example, a half.

  The post-processing unit 103 executes non-sort processing and position shift processing for each bundle discharge. In the non-sort processing, the recording paper output from the image forming apparatus 101 is discharged as it is to the paper discharge tray 104, and in the position shift processing for each bundle discharge, the recording paper is placed at a different position on the paper discharge tray 104 for each recording paper bundle. Drain the bundle.

  Next, the electrical configuration of the image forming apparatus 101 will be described.

  FIG. 3 is a block diagram illustrating an electrical configuration of the image forming apparatus 101.

  As shown in FIG. 3, the image forming apparatus 101 includes a CPU 171 that performs basic control of the image forming apparatus 101, a ROM 174 in which a control program is written, a work RAM 175 as a work area of the CPU 171, and an input / output port 173. Prepare. The CPU 171, the input / output port 173, the ROM 174, and the RAM 175 are connected by an address bus or a data bus. The input / output port 173 is connected to various loads (not shown) such as a motor and a clutch for controlling the image forming apparatus 101, and a sensor (not shown) for detecting the position of the transfer material P.

  The CPU 171 sequentially performs input / output control via the input / output port 173 in accordance with the contents of the control program stored in the ROM 174, and executes the image forming operation as described above. An operation unit 172 is connected to the CPU 171 and controls display means and key input means of the operation unit 172. The operator can instruct the CPU 171 to switch the image forming operation mode and the operation unit display via the key input means. The CPU 171 displays the state of the image forming apparatus 101 and the operation mode setting by key input.

  As shown in FIG. 3, an external I / F processing unit 400, an image memory unit 300, an image forming unit 200, an image adjustment unit 700, and an image adjustment processing control unit 800 are connected to the CPU 171. The external I / F processing unit 400 transmits and receives image data and processing data from an external device such as a PC. The image memory unit 300 performs image expansion processing, storage processing for temporarily storing images, and the like. The image forming unit 200 performs predetermined processing on the line image data transferred from the image memory unit 300 so that the exposure unit 7 exposes the photosensitive drum.

  Next, the image memory unit 300 will be described in detail with reference to FIG. FIG. 4 is a block diagram illustrating a schematic configuration of the image memory unit 300.

  As illustrated in FIG. 4, the image memory unit 300 includes a page memory 301, a memory controller 302, and a compressed data decompression unit 303. The page memory 301 is configured by a memory such as a DRAM. The memory controller 302 performs input / output of images such as writing of image data received from the external I / F processing unit 400 to the page memory 301 and reading of images from the page memory 301 to the image forming unit 200. That is, the memory controller 302 performs access between the page memory 301 and the image forming unit 200.

  Further, the memory controller 302 determines whether the image data from the external device received from the external I / F processing unit 400 is compressed data. If it is determined that the image data is compressed data, the memory controller 302 performs a compressed data decompression process. After performing decompression processing using the unit 303, processing for writing to the page memory 301 is performed.

  The memory controller 302 further adjusts access to the page memory 301 for generation of a DRAM refresh signal of the page memory 301, writing from the external I / F processing unit 400, and reading to the image forming unit 200. The memory controller 302 controls the write address to the page memory 301, the read address from the page memory 301, the read direction, and the like according to instructions from the CPU 171.

  Next, the configuration of the external I / F processing unit 400 will be described with reference to FIG. FIG. 5 is a block diagram illustrating a schematic configuration of the external I / F processing unit 400.

  As illustrated in FIG. 5, the external I / F processing unit 400 includes a USB I / F unit 401, a Centro I / F unit 402, and a network I / F unit 403. The external I / F processing unit 400 transmits image data and print command data transmitted from the external device 500 as an external device to any of the USB I / F unit 401, the Centro I / F unit 402, or the network I / F unit 403. To receive via. Also, the external I / F processing unit 400 transmits the status information of the image forming apparatus 101 determined by the CPU 171 to the external apparatus 500. Here, the external device 500 is a computer, a workstation, or the like.

  Print command data received from the external device 500 via any of the USB I / F unit 401, the Centro I / F unit 402, or the network I / F unit 403 is processed by the CPU 171. The CPU 171 uses the image forming unit 200, the input / output port 173 in FIG. 3, and the like to set the print operation to be executed and the execution timing of the print operation.

  In the external I / F processing unit 400, image data received from the external device 500 via any of the USB I / F unit 401, the Centro I / F unit 402, or the network I / F unit 403 is converted into print command data. It is transmitted to the image memory unit 300 according to the timing based on it. Then, the image memory unit 300 processes the received image data so that the image forming unit 200 performs image formation.

  Next, the configuration of the post-processing apparatus 102 will be described with reference to FIG. FIG. 6 is a block diagram showing an electrical configuration of the post-processing apparatus 102.

  As illustrated in FIG. 6, the post-processing device 102 includes a CPU 601, a RAM 602, and a ROM 603, and the CPU 601 performs overall control of the entire post-processing device 102 based on a predetermined control program stored in the ROM 603. A RAM 603 is a work area for the CPU 602. In addition, the post-processing device 102 includes a status detection unit 604 that detects the operation status of the post-processing device 102. The status detection unit 604 can detect whether or not a post-processing operation is being executed in the post-processing device 102.

  As shown in FIG. 2, the image forming apparatus 101 is disposed, for example, between the image forming unit 1 and the secondary transfer facing roller 10 at a position facing the lower surface of the intermediate transfer belt 8. An image adjustment function including the optical sensor 60 and the density sensor 70 is provided. The image adjustment function is realized by an image adjustment unit 700 shown in FIG. In this embodiment, the image adjustment function includes a color misregistration adjustment function (registration adjustment function) and a toner density adjustment function. Hereinafter, the image adjustment function will be described.

  First, the color misregistration adjustment function will be described. The color misregistration adjustment function is realized by performing color misregistration adjustment processing.

  In the color misregistration adjustment process, as shown in FIG. 8 using the image forming unit 1, a measurement toner pattern (hereinafter referred to as “horizontal bar” pattern) of each color having a predetermined width extending in the main scanning direction on the intermediate transfer belt 8. ) And a measuring toner pattern (hereinafter referred to as a “character shape” pattern) for each color of the character shape. A pair of measurement toner patterns is formed on the front side (front side in FIG. 1) and the back side (back side in FIG. 1) of the intermediate transfer belt 8. Next, the width (see 8-a) between the “horizontal bar” patterns of each color formed on the intermediate transfer belt 8 and the open side width (see 8-b) of the “cross-shaped” pattern of each color are optical sensors. 60 is detected. The detection signal is converted into an electric signal by the light receiving circuit 701 and stored in the pattern width storage unit (register) 702. Next, the detection signal stored in the pattern width storage unit 702 is analyzed by the analysis unit 703. Based on the analysis result, the CPU 171 of the image forming apparatus 101 controls the image forming unit 200 to adjust the image writing position. To do.

  In the analysis unit 703, for example, the value of the width 8-a of the yellow “horizontal bar” pattern and the magenta “horizontal bar” pattern in the sub-scanning direction and a predetermined sub-scan stored in the ROM 704 in advance. Compare with the threshold. As a result of this comparison, when the detection value of the optical sensor 60 is larger than the sub-scanning threshold value, the writing timing of the image forming unit 1M in the sub-scanning direction of the output image is delayed. In this case, the CPU 171 adjusts the writing start timing of the image forming unit 1M in the sub-scanning direction by a value corresponding to the difference between the detection value and the sub-scanning threshold value. In this way, the registration deviation in the sub-scanning direction is corrected.

  The analysis unit 703 also compares the width of the “character shape” pattern with a predetermined value, and the CPU 171 adjusts the writing timing in the main scanning direction by a value corresponding to the difference. For example, when an image is written from the left direction in FIG. 8, if the value of the open side width 8-b of the “character shape” pattern is larger than a predetermined main scanning threshold value stored in advance in the ROM 704, the output image The writing timing in the main scanning direction is delayed. In this case, the CPU 171 adjusts the writing timing in the main scanning direction to be delayed by a value corresponding to the difference between the detected value and the main scanning threshold value. In this way, the registration deviation in the main scanning direction is corrected.

  As described above, the writing timing in the main scanning direction and the writing timing in the sub-scanning direction are corrected, and the correction value is stored in a backup RAM (not shown). The “horizontal bar” pattern and the “cross-shaped” pattern reflecting the correction value are formed when performing registration correction. Thereby, the registration deviation can be converged.

  Next, the toner density adjustment function will be described. The toner density adjustment function is realized by performing toner density adjustment processing.

  In the present embodiment, the developing devices 4a, 4b, 4c, and 4d include a two-component developer in which toner and a carrier are mixed as a developer, and the image forming apparatus 101 uses the two-component developer. It is assumed that the development method used is adopted. When such a two-component developer is used, it is necessary to keep the ratio of toner and carrier (T / C ratio) in the developing device constant to maintain high image quality. For this purpose, toner density adjustment processing is performed.

  In the toner density adjustment process, a measurement toner pattern (patch) having a predetermined target density is formed on the surface of the intermediate transfer belt 8, the density of the patch is detected by the density sensor 70, and the detected density and the current density are detected. The analysis unit 703 compares the target density. The target density is determined by the set toner replenishment amount and the toner / carrier ratio, and is stored in the ROM 704 in advance. As a result of the comparison, if it is determined that the detected patch density is higher than the target density, toner supply amount adjustment such as reducing the toner supply amount of the corresponding color is performed to lower the toner density. When it is determined that the detected patch density is lower than the target density, toner supply amount adjustment such as increasing the corresponding toner supply amount is performed to increase the toner density. In the toner replenishment amount adjustment, the distance from the target density is calculated from the difference between the detected patch density and the target density, and the toner replenishment amount is adjusted. In the toner density adjustment process, similarly to the color misregistration adjustment process, the light receiving circuit 701 converts the detection signal of the density sensor 70 into an electrical signal, and the CPU 171 controls the image forming unit 200 to adjust the toner supply amount. .

  Further, as shown in FIG. 9, the image forming apparatus 101 includes an image adjustment process control unit 800 for controlling execution of the image adjustment process. The image adjustment process control unit 800 operates in an image adjustment control process described later. FIG. 9 is a block diagram illustrating a schematic configuration of the image adjustment processing control unit 800.

  As shown in FIG. 9, the image adjustment processing control unit 800 includes an image adjustment processing execution determination unit 801, an output counter 802, a video counter 803, a threshold setting unit 804, a post-processing operation status determination unit 805, an image An adjustment processing prohibition unit 806.

  The image adjustment process execution determination unit 801 determines whether image adjustment (color shift adjustment or toner density adjustment) is necessary in an image adjustment control process described later.

  An output counter 802 counts the number of transfer materials on which an image has been formed in the image forming apparatus 101 and calculates the number of formed images. The output counter 802 counts the number of transfer materials on which an image is formed independently for each type of image adjustment processing. In other words, the output counter 802 calculates the color misregistration adjustment count value by counting the number of transfer materials on which an image is formed for color misregistration adjustment processing, and also transfers the image formed for toner density adjustment processing. The count value for toner density adjustment is calculated by counting the number of sheets.

  The video counter 803 counts the image data signal output to the image forming unit 200 for each color to calculate the video count number. The video counter 803 counts image data signals independently for yellow, cyan, magenta, and black colors to be developed. That is, the video counter 803 counts the image data signal for the color misregistration adjustment process to calculate the color misregistration adjustment count value, and counts the image data signal for the toner density adjustment process to adjust the toner density. Calculate the count value.

  The threshold setting unit 804 stores a predetermined threshold for the image adjustment processing execution determination unit 801 to determine whether image adjustment is necessary. In other words, the threshold setting unit 804 stores a color misregistration adjustment threshold in which the number of image formations that can be determined to be necessary to perform color misregistration adjustment or a video count for each color is set. Further, the threshold setting unit 804 stores a toner adjustment threshold in which the number of image formations or the video count for each color that can be determined to require execution of toner density adjustment is set. The color misregistration adjustment threshold and the toner adjustment threshold are values obtained in advance through experiments or the like, for example.

  As will be described later, the image adjustment processing execution determination unit 801 compares the color misregistration adjustment count value, which is the count value of the output counter 802 or the video counter 803, with the color misregistration adjustment threshold value of the threshold value setting unit 804 to determine the color It is determined whether or not the deviation adjustment needs to be executed. Also, the image adjustment processing execution determination unit 801 compares the toner concentration adjustment count value, which is the count value of the output counter 802 or the video counter 803, with the toner concentration adjustment threshold value of the threshold setting unit 804, and performs toner concentration adjustment. Determine if it needs to be done.

  The post-processing operation status determination unit 805 is connected to the status detection unit 604 of the post-processing device 102, and whether or not the post-processing device 102 is executing the post-processing operation based on the detection result of the status detection unit 604. Is determined.

  The image adjustment processing prohibition unit 806 prohibits or starts execution of the image adjustment processing in the image forming unit 200 via the CPU 171 as will be described later.

  Note that the functions of the image adjustment unit 700 and the image adjustment processing control unit 800 described above may be performed by the CPU 171.

  Next, image adjustment control processing executed in the image forming apparatus 101 will be described with reference to FIG.

  FIG. 10 is a flowchart of the image adjustment control process. The image adjustment process control process is a process for controlling execution of the image adjustment process.

  This process is started when an image formation start signal is issued. First, an image forming operation is started, and an image forming process for forming an image on the transfer material P is executed in the image forming unit 200 (step S1001). Next, it is determined whether or not image adjustment is necessary (step S1002). In step S <b> 1002, the image adjustment processing execution determination unit 801 determines whether the image forming number of the output counter 802 or the video count number of the video counter 803 has reached the threshold setting unit 804. In step S1002, it is determined whether or not it is necessary to execute each type of image adjustment processing. That is, the color misregistration adjustment count value is compared with the color misregistration adjustment threshold value, and the toner density adjustment count value is compared with the toner density adjustment threshold value. When the color misregistration adjustment count value has reached the color misregistration adjustment threshold, it is determined that the color misregistration adjustment processing is necessary, and when the toner density adjustment count value has reached the toner density adjustment threshold, the toner density adjustment processing is performed. Is determined to be necessary.

  If it is determined in step S1002 that image adjustment is necessary, the operation status of the post-processing apparatus 102 is confirmed (step S1003). The determination in step S1003 is performed by the post-processing operation status determination unit 805. When the post-processing apparatus 102 is operating, for example, when the stapling operation is being performed, the post-processing operation may adversely affect the measurement toner pattern formed for image adjustment. The execution of the performed image adjustment processing is prohibited (step S1004), and the process waits until the operation of the post-processing apparatus 102 is completed (step S1005). In step S <b> 1004, the measurement toner pattern (“horizontal bar” pattern, “cross-shaped” pattern, or patch) (see FIG. 8) in the image forming unit 1 is formed, and the “horizontal bar” pattern or The detection of the “character shape” pattern or the detection of the patch density by the density sensor 70 is prohibited. Further, the prohibition of the image adjustment process in step S1004 is performed by the image adjustment process prohibition unit 806 prohibiting the execution of the image adjustment process of the image forming unit 200 via the CPU 171.

  Next, when the operation of the post-processing apparatus 102 is completed, the image adjustment processing prohibition unit 806 cancels the prohibition of the image adjustment processing, and the image forming unit 200 starts the image adjustment processing determined to be necessary in step S1002 (step S1006). ). In step S1006, image adjustment processing is executed as described above, and measurement toner pattern formation, measurement toner pattern detection, and image adjustment (color misregistration adjustment or toner density adjustment) are performed.

  On the other hand, if the post-processing apparatus 102 is not operating in step S1003, the process immediately proceeds to step S1006.

  Next, when the image adjustment process is completed in step S1006, it is confirmed whether or not there is image data of the next page to be image formed (step S1007). If there is image data of the next page, the process of step S1001 is performed. Returning, the image forming process is continued to form the image of the next page on the recording medium. On the other hand, if there is no next page, the process is terminated.

  If it is determined in step S1002 that image adjustment is not necessary, the process immediately proceeds to step S1007.

  In step S1006, when the image adjustment process determined to be necessary in step S1002 is executed, the corresponding count value (color misregistration adjustment count value or toner density adjustment count value) is cleared.

  As described above, the image forming system 100 according to the first embodiment of the present invention determines that it is necessary to adjust the image forming conditions (image writing timing or toner density) of the image forming unit 1, In addition, when the post-processing device 102 is performing a post-processing operation, execution of the image adjustment process is prohibited. That is, the formation of the measurement toner pattern on the intermediate transfer belt 8 and the detection of the measurement toner pattern are prohibited. Therefore, the measurement toner pattern is not formed on the intermediate transfer belt 8 while the post-processing apparatus 102 is performing the post-processing operation. Accordingly, it is possible to prevent occurrence of uneven formation and uneven density in the measurement toner pattern due to vibration caused by the post-processing operation of the post-processing device 102. Further, it is possible to prevent the measurement toner pattern detection accuracy from being lowered due to vibrations caused by the post-processing operation of the post-processing device 102. This prevents the image forming condition from being adjusted based on the measurement toner pattern formed during the post-processing operation or based on the detection result of the measurement toner pattern detected during the post-processing operation. can do. Therefore, it is possible to prevent the image adjustment based on the measurement toner pattern detected with poor accuracy by detecting the measurement toner pattern in which the formation unevenness or the density unevenness is detected and performing image adjustment. The image adjustment of the unit 1 can be performed optimally. Thereby, a desired optimum image can be stably formed.

  Note that the effect described above is that the post-processing apparatus is installed at a location relatively close to the image forming unit such as the upper part of the image forming apparatus main body, and the image with high possibility that the vibration of the post-processing operation affects the image formation. This is particularly effective in the forming apparatus.

  Next, an image forming system 100 according to a second embodiment of the present invention will be described.

  The image forming apparatus according to the present embodiment differs from the image forming system 100 according to the first embodiment of the present invention in the content of the image adjustment control process. Hereinafter, with respect to the image forming system 100 according to the first embodiment of the present invention, the same components are denoted by the same reference numerals, and redundant description is omitted, and only different portions will be described.

  FIG. 11 is a flowchart of an image adjustment control process executed in the image forming apparatus 101 according to this embodiment.

  In this process, when the image adjustment of the image forming unit 1 is performed, if the post-processing apparatus 102 is in the post-processing operation, the timing for performing the image adjustment process is changed.

  Similar to the first embodiment, this processing is started when an image formation start signal is issued. First, an image forming operation is started, and an image forming unit 200 forms an image on the transfer material P. A forming process is executed (step S1101). Next, it is determined whether or not image adjustment is necessary (step S1102). The process of step S1102 is performed similarly to the process of step S1002 of FIG.

  If it is determined in step S1102 that image adjustment is necessary, the operation status of the post-processing device 102 is confirmed (step S1103) as in step S1003 of FIG. When the post-processing apparatus 102 is in operation, for example, when the stapling operation is in progress, the post-processing operation may affect the measurement toner pattern formed for image adjustment. Is changed (step S1104).

  In step S1104, for example, the image adjustment process is executed so that the image adjustment process is executed after the image formation process in step S1101 is executed for all image data for which an image output instruction has been issued from an external device in the current process. Change the timing. In step S1104, a flag (Flag = 1) indicating that the image adjustment timing has been changed is set. When the process of step S1104 ends, the process proceeds to step S1106.

  On the other hand, if the post-processing apparatus 102 is not operating in step S1103, image adjustment processing is started (step S1105). In step S1105, image adjustment processing is executed as in step S1006 of FIG. 10 described above, and measurement toner pattern formation, measurement toner pattern detection, and image adjustment (color shift adjustment or toner density adjustment) are performed. . Next, when the image adjustment process ends in step S1105, the process proceeds to step S1106.

  In step S1106, it is confirmed whether there is image data of the next page to be image-formed. If there is a next page, the process returns to step S1101, and the image forming process is continued on the recording medium. Create an image of the page. On the other hand, if there is no next page, it is determined whether Flag = 1 or not (step S1107).

  If Flag = 1, since the image adjustment execution timing has been changed in step S1104, the image adjustment process is started and executed in the same manner as in step S1105 (step S1108), and this process ends. On the other hand, if Flag = 1 is not true, this processing is immediately terminated.

  If it is determined in step S1102 that image adjustment is not necessary, the process immediately proceeds to step S1106.

  If there is a next page in step S1106, it is considered in step S1102 executed after step S1101 whether or not the image adjustment timing has already been changed in step S1104. That is, if the image adjustment timing has already been changed in step S1104, that is, if Flag = 1, it is determined that image adjustment is not necessary, and the process proceeds to step S1106.

  When the image adjustment process determined to be necessary in step S1102 is executed in steps S1105 and S1108, the corresponding count value (color misregistration adjustment count value or toner density adjustment count value) is cleared.

  As described above, according to the image forming system according to the second embodiment of the present invention, it is determined that the image forming condition (image writing timing or toner density) of the image forming unit 1 is adjusted, and the post-processing device 102 is adjusted. However, when the post-processing operation is being executed, the execution timing of the image adjustment processing is changed, and the image adjustment processing is executed after the output of all the image data is finished and the operation of the post-processing device 102 is finished. Therefore, the same effects as those of the first embodiment of the present invention can be obtained, and the image adjustment of the image forming unit 1 can be optimally performed. Thereby, a desired optimum image can be stably formed.

  Next, an image forming system according to a third embodiment of the present invention will be described.

  The image forming apparatus according to the present embodiment differs from the image forming system 100 according to the first embodiment of the present invention in the content of the image adjustment control process. Hereinafter, with respect to the image forming system 100 according to the first embodiment of the present invention, the same components are denoted by the same reference numerals, and redundant description is omitted, and only different portions will be described.

  FIG. 12 is a flowchart of image adjustment control processing executed in the image forming apparatus according to the present embodiment.

  As shown in FIG. 12, the image adjustment control process in this embodiment is set as a post-process executed by the post-processing device 102 between step S1002 and step S1003 of the image adjustment control process of FIG. The difference is that step S1201 for confirming the type of processing is performed.

  In step S <b> 1201, the post-processing operation status determination unit 805 accesses the status detection 604 of the post-processing device 102 and determines the type of post-processing selected to be executed in the post-processing device 102. In the post-processing device 102, when the non-sort process or the position shift process for each bundle discharge is selected as the post process to be executed, the process proceeds to step S1006 and the image adjustment process is started. The non-sort process or the position shift process for each bundle discharge has less vibration generated during the operation, and less vibration transmitted to the image forming unit 1 or the like. For this reason, even if the image adjustment process is performed during the non-sort process or the position shift process for each bundle discharge, the image adjustment is not appropriately performed. Therefore, in step S1201, when the non-sort process or the position shift process for each bundle discharge is selected as the post-process, the image adjustment process is started.

  On the other hand, if the post-processing apparatus 102 selects the post-processing to be executed as the stapling process, the punching process, or the folding process, the process proceeds to step S1003 to determine whether the post-processing operation is in progress. If the image adjustment process is performed during the staple process, the punch process, or the folding process, the image adjustment process cannot be optimally performed as described above. In this case, as in the first embodiment, Whether or not the selected post-processing is being executed is confirmed, and if it is not being executed, the image adjustment processing is started.

  Also in the third embodiment of the present invention, the same effects as in the first embodiment of the present invention can be achieved.

  In the image adjustment control process according to the second embodiment of the present invention, the process of step S1201 may be performed between step S1102 and step S1103. In this case, in step S1201, when the post-processing device 102 is selected as a post-process to execute the non-sort process or the position shift process for each bundle discharge, the process proceeds to the process of step S1105, and the image adjustment process is started. On the other hand, in step S1201, if the post-processing device 102 selects the post-processing to be executed as staple processing, punch processing, or folding processing, the process proceeds to step S1103 to determine whether post-processing is in progress. To do.

  In the first to third embodiments of the present invention, the color misregistration adjustment process or the toner density adjustment process is executed as the image adjustment process. However, the image adjustment process is not limited to this. . Further, although the color misregistration adjustment processing is performed by forming the measurement toner pattern shown in FIG. 8, FIG. 8 illustrates the measurement toner pattern, and the measurement toner pattern of another form is read. The result may be reflected in the formed image.

  In each of the above embodiments, the image forming apparatus has been described as a small-sized image forming apparatus that does not include a reading unit such as a scanner, but may be an image forming apparatus that includes a reading unit.

  Another object of the present invention is to supply a storage medium storing software program codes for realizing the functions of the above-described embodiments to a system or apparatus, and the computer of the system or apparatus (or CPU, MPU, or the like). Is also achieved by reading and executing the program code stored in the storage medium.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the program code and the storage medium storing the program code constitute the present invention. .

  Examples of the storage medium for supplying the program code include a floppy (registered trademark) disk, a hard disk, a magneto-optical disk, a CD-ROM, a CD-R, a CD-RW, a DVD-ROM, a DVD-RAM, and a DVD. An optical disc such as RW or DVD + RW, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used. Alternatively, the program code may be downloaded via a network.

  Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (Operating System) running on the computer based on the instruction of the program code. Includes a case where the functions of the above-described embodiments are realized by performing part or all of the actual processing.

  Furthermore, after the program code read from the storage medium is written to a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the expanded function is based on the instruction of the program code. This includes a case where a CPU or the like provided on the expansion board or the expansion unit performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.

1 is a cross-sectional view showing a schematic configuration of an image forming system according to a first embodiment of the present invention. It is sectional drawing which shows schematic structure of the image forming apparatus in FIG. FIG. 2 is a block diagram illustrating an electrical configuration of the image forming apparatus in FIG. 1. It is a block diagram which shows schematic structure of the image memory part in FIG. FIG. 4 is a block diagram illustrating a schematic configuration of an external I / F processing unit in FIG. 3. It is a block diagram which shows the electrical structure of the post-processing apparatus in FIG. It is a block diagram which shows schematic structure of the image adjustment part in FIG. FIG. 6 is a diagram illustrating an example of a measurement toner pattern formed in an image adjustment process. FIG. 2 is a block diagram illustrating a schematic configuration of an image adjustment processing control unit provided in the image forming apparatus of FIG. 3 is a flowchart of image adjustment control processing executed in the image forming apparatus of FIG. 1. It is a flowchart of the image adjustment control process performed in the 2nd Embodiment of this invention. It is a flowchart of the image adjustment control process performed in the 3rd Embodiment of this invention.

Explanation of symbols

1 Image forming units 1Y, 1M, 1C, 1Bk Image forming units 2a, 2b, 2c, 2d Photosensitive drum (image carrier)
3a, 3b, 3c, 3d Primary chargers 4a, 4b, 4c, 4d Developers 5a, 5b, 5c, 5d Transfer rollers 6a, 6b, 6c, 6d Drum cleaner 7 Exposure section 8 Intermediate transfer belt (image carrier)
12 Secondary transfer roller 16 Fixing device 60 Optical sensor 70 Density sensor 100 Image forming system 101 Image forming apparatus 102 Post-processing device 604 Status detection unit 700 Image adjustment unit 800 Image adjustment processing control unit 801 Image adjustment processing execution determination unit 802 Output counter 803 Video counter 804 Threshold setting unit 805 Post-processing operation status determination unit 806 Image adjustment processing prohibition unit

Claims (7)

An image forming apparatus having image forming means for transferring a toner image developed on an image carrier based on image information to a recording medium, and a post-processing apparatus for performing post-processing of the recording medium discharged from the image forming apparatus In an image forming system comprising:
Toner pattern forming means for forming a measurement toner pattern on the image carrier;
Reading means for reading the measurement toner pattern formed on the image carrier;
Determining means for determining whether or not to adjust the image forming conditions of the image forming means;
Prohibition of prohibiting formation of the measurement toner pattern or reading of the measurement toner pattern when the determination means determines that the image forming conditions are to be adjusted and the post-processing apparatus is executing the post-processing. And an image forming system.   The image forming system according to claim 1, wherein when the post-processing is finished, the prohibiting unit cancels prohibition of the formation of the measurement toner pattern or reading of the measurement toner pattern.   In the image forming period in which the image forming unit forms an image on the recording medium, the prohibiting unit prohibits the formation of the measurement toner pattern or the reading of the measurement toner pattern. The image forming system according to claim 1, wherein the prohibition of the measurement toner pattern formation or the reading of the measurement toner pattern is canceled. Post-processing of the post-processing device includes a first process for binding the recording medium, and a second process for discharging the recording medium as it is without post-processing of the recording medium,
4. The image forming system according to claim 1, wherein the prohibiting unit operates according to the first processing and prohibits the operation according to the second processing. 5.   The toner pattern forming unit forms a registration shift measurement pattern for detecting a registration shift as the measurement toner pattern, and forms the image based on reading information of the registration shift measurement pattern read by the reading unit. 4. The image forming system according to claim 1, further comprising image adjusting means for adjusting conditions.   The toner pattern forming unit forms a density measurement pattern for detecting a density shift as the measurement toner pattern, and an image for adjusting the image forming condition based on reading information of the density measurement pattern read by the reading unit. The image forming system according to claim 1, further comprising an adjusting unit. An image forming apparatus having image forming means for transferring a toner image developed on an image carrier based on image information to a recording medium, and a post-processing apparatus for performing post-processing of the recording medium discharged from the image forming apparatus In an image forming system control method comprising:
A toner pattern forming step of forming a measurement toner pattern on the image carrier;
A reading step of reading the measurement toner pattern formed on the image carrier;
A determination step of determining whether or not to adjust image forming conditions of the image forming unit;
If the determination step determines that the image forming conditions are to be adjusted and the post-processing device is executing the post-processing, the measurement toner pattern formation step or the measurement toner pattern reading step is prohibited. A control method for an image forming system.

Images