JP2010130076A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of associating an image information used as an image formation object with a read image to generate an unevenness correction information. <P>SOLUTION: Original image data is compounded with identification information by an information synthesis portion 212 to generate composite image data. By an image formation unit, an image expressed by the composite image data is formed at a recording medium. The original image data and the identification information are associated each other and stored at an original image data storage 204. The image formed at the recording medium by the image reading unit is read, and image data and identification information are acquired from the read image by an image separator 216. The original image data associated with the identification information are read by an original image data reader 218. Unevenness in the image is detected by an unevenness detector 220, based on the original image data and the read image data. An unevenness correction information is generated by an unevenness correction information generator 222, based on the unevenness in the detected image. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus.

  Conventionally, various techniques have been proposed for correcting in-plane unevenness using print image data. For example, an image forming apparatus that extracts a region that can be used as a patch from a document image and detects a color is known (Patent Document 1).

  In addition, when correcting unevenness using an actual image, if there is no appropriate area in the document, using the fact that the in-plane unevenness is stable for a certain period of time, extract the area across multiple documents, An image processing system that forms a correction pattern is known (Patent Document 2).

Also, an image processing system that extracts a portion where uniform colors are continuous is known as a region for detecting unevenness (Patent Document 3). There is also known an image forming apparatus that detects the position of a photoconductor and changes the correction amount according to the position of the photoconductor (Patent Document 4).
JP 2005-217747 A JP 2007-59974 A JP 2007-36330 A JP 2000-267363 A

  Even when no reading device is provided inside the apparatus, the image information that is the object of image formation and the image information of the read image can be correlated to generate unevenness correction information. An object is to provide a forming apparatus.

  In order to achieve the above object, an image forming apparatus according to the first aspect of the present invention synthesizes image information that is an image formation target and identification information for identifying the image information, thereby combining the combined image information. Synthesizing means for generating the image, image forming means for forming an image represented by the synthesized image information synthesized by the synthesizing means on a recording medium, and image storage means for storing the image information and the identification information correspondingly An image reading unit that reads an image formed on the recording medium, an image information acquisition unit that acquires the image information and the identification information from the composite image information of the image read by the image reading unit, and the image Image reading means for reading the image information corresponding to the acquired identification information from the storage means, the acquired image information, and read by the image reading means. An unevenness detecting means for detecting unevenness of the image based on the image information, and an unevenness correction information generating means for generating unevenness correction information for correcting the unevenness based on the unevenness of the image detected by the unevenness detecting means. It is comprised including.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the image forming unit forms a latent image on the surface of the image holding body based on the rotatable image holding body and the composite image information. A latent image forming means for forming; a developing means for developing a latent image on the surface of the image carrier with a developer; and a transfer means for transferring the developed image to a recording medium. Position detecting means for detecting a positional relationship with a rotational position of the body, wherein the synthesizing means is a position indicating the positional relationship detected by the image information, identification information of the image information, and the positional detecting means. And the related information is combined to generate the composite image information, and the image information acquisition unit obtains the image information, the identification information, and the position from the composite image information of the image read by the image reading unit. Related information And, wherein the correcting information generating means, based on the unevenness of said detected image by the unevenness detecting means generates the non-uniformity correction information for correcting the unevenness for the acquired position relation information positional relationships shown.

  According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the combining unit includes the image information, identification information of the image information, and date / time information indicating a current date or date / time. The combined image information is generated, and the image information acquisition unit acquires the image information, the identification information, and the date / time information from the combined image information of the image read by the image reading unit. The correction information generation means generates the unevenness correction information based on the unevenness of the image detected by the unevenness detection means, the acquired date / time information, and the current date or date / time.

  According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the combining unit includes the image information, identification information of the image information, and the image information. The composite image information is generated by combining the direction information indicating the direction of a predetermined direction, and the image information acquisition unit is configured to generate the composite image information from the composite image information of the image read by the image read unit. The identification information and the direction information are acquired, and the unevenness detection unit is configured to determine the acquired image information and the image information read by the image reading unit based on the acquired direction information. The image unevenness is detected in correspondence with the predetermined direction indicated by the direction information.

  According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects, the synthesizing unit identifies the image information, identification information of the image information, and the apparatus itself. And the apparatus information for generating the composite image information, and the image information acquisition means, from the composite image information of the image read by the image reading means, the image information, the identification information, The device information is acquired, and the unevenness correction information generation unit does not generate the unevenness correction information when the acquired device information is not the device information of the device itself.

  As described above, according to the image forming apparatus of the first aspect, even when the reader is not provided in the apparatus, the image information that is the object of image formation and the image of the read image The effect that the unevenness correction information can be generated in correspondence with the information is obtained.

  According to the image forming apparatus of the second aspect, it is possible to generate unevenness correction information for correcting unevenness with respect to the positional relationship between the recording medium and the rotational position of the image carrier.

  According to the image forming apparatus of the third aspect, it is possible to generate the unevenness correction information according to the date and time information when the image is formed.

  According to the image forming apparatus of the fourth aspect, it is possible to detect the unevenness by matching the directions of the image information to be image formed and the image information of the read image.

  According to the image forming apparatus of the fifth aspect, when the apparatus information obtained from the read image is not the apparatus information of the own apparatus, it is possible to prevent generation of unevenness correction information. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the embodiment of the present invention, a case where the present invention is applied to an image forming apparatus will be described as an example.

  As shown in FIG. 1, the image forming apparatus 10 according to the first embodiment includes an image reading unit 12, an image forming unit 14, an intermediate transfer belt 16, a paper feeding unit 17, a paper conveyance path 18, a fixing device 19, The image processing apparatus 20 includes an image forming control apparatus 21, a paper discharge unit 22, and a user interface (UI) apparatus 23.

  The image forming apparatus 10 has a function as a full-color copying machine using the image reading unit 12 and a function as a facsimile in addition to a printer function for printing image data received from a personal computer (not shown). ing.

  First, the outline of the image forming apparatus 10 will be described. In the upper part of the image forming apparatus 10, an image reading unit 12, an image processing apparatus 20, and an image forming control apparatus 21 are arranged. The image reading unit 12 reads an image displayed on the document 30 and outputs it to the image processing apparatus 20. The image processing apparatus 20 performs image processing such as correction processing described later on the read image data input from the image reading unit 12 or image data input from a personal computer or the like via a network line such as a LAN. And output to the image formation control device 21. The image forming control device 21 controls the image forming unit 14 based on the image data subjected to image processing. Note that the image formation control device 21 may be included in the image processing device 20 as a part of the image processing device 20.

  A UI device 23 such as a touch panel is provided on the upper surface of the image forming apparatus 10. The UI device 23 displays control information and instruction information of the image forming apparatus 10 and accepts input by the user such as instruction information. That is, the user can operate the image forming apparatus 10 via the UI device 23. Note that the UI device 23 may accept only an input such as a switch, may perform only an output such as a display, or may be a combination of these.

  Below the image reading unit 12, a plurality of image forming units 14 are arranged corresponding to the colors constituting the color image. In this example, the first image forming unit 14K, the second image forming unit 14Y, and the third image forming corresponding to each color of black (K), yellow (Y), magenta (M), and cyan (C). The unit 14M and the fourth image forming unit 14C are arranged horizontally at a certain interval along the intermediate transfer belt 16. The intermediate transfer belt 16 rotates as an intermediate transfer member in the direction of an arrow A in the figure, and these four image forming units 14K, 14Y, 14M, and 14C have different colors based on image data input from the image processing apparatus 20. Toner images are sequentially formed, and transferred (primary transfer) to the intermediate transfer belt 16 at a timing at which the plurality of toner images are superimposed on each other. The order of the colors of the image forming units 14K, 14Y, 14M, and 14C is not limited to the order of black (K), yellow (Y), magenta (M), and cyan (C). ), Magenta (M), cyan (C), black (K), and the like.

  The sheet conveyance path 18 is disposed below the intermediate transfer belt 16. The recording paper 32 supplied from the paper supply means 17 is transported on the paper transport path 18, and the toner images of each color transferred onto the intermediate transfer belt 16 are collectively transferred (secondary transfer). The transferred toner image is fixed by the fixing device 19 and discharged to the outside along the arrow B.

  Next, each configuration of the image forming apparatus 10 will be described in detail. As shown in FIG. 1, the image reading unit 12 includes a platen glass 124 on which the document 30 is placed, a platen cover 122 that presses the document 30 onto the platen glass 124, and an image of the document 30 placed on the platen glass 124. And an image reading unit 130 for reading. The image reading unit 130 illuminates the original 30 placed on the platen glass 124 with a light source 132, and displays a reflected light image from the original 30 as a full-rate mirror 134, a first half-rate mirror 135, and a second half-rate. Scanning exposure is performed on an image reading element 138 made of a CCD or the like through a reduction optical system including a mirror 136 and an imaging lens 137, and the color material reflected light image of the document 30 is transferred to predetermined dots by the image reading element 138. It is configured to read at a density (for example, 16 dots / mm).

  The image processing apparatus 20 performs predetermined image processing such as color conversion on the read image data read by the image reading unit 12 or image data input via a network line. The color material reflected light image of the document 30 read by the image reading unit 12 is, for example, document reflectance data of three colors of red (R), green (G), and blue (B). By the image processing by 20, the original color material gradation data of four colors of yellow (Y), magenta (M), cyan (C), and black (K) is converted.

  The image formation control device 21 generates a pulse signal according to the image data (YMCK) input from the image processing device 20 and outputs the pulse signal to the optical scanning device 140. More specifically, the image formation control device 21 performs the first optical scanning device 140K, the second optical scanning device 140Y, the third optical scanning device 140M, and the fourth light, which will be described later, based on the image data. A pulse signal is output to the scanning device 140C to form an image.

  The first image forming unit 14K, the second image forming unit 14Y, the third image forming unit 14M, and the fourth image forming unit 14C are arranged in parallel in the horizontal direction at a certain interval. The configuration is almost the same except that the color of the image to be changed is different. Accordingly, the first image forming unit 14K will be described below. The configuration of each image forming unit 14 is distinguished by adding K, Y, M, or C.

  The image forming unit 14K forms an electrostatic latent image by an optical scanning device 140K that scans a laser beam in accordance with image data input from the image processing device 20, and a laser beam scanned by the optical scanning device 140K. And an image forming apparatus 150K.

  The optical scanning device 140K modulates the semiconductor laser 142K according to the black (K) image data, and emits the laser light LB (K) from the semiconductor laser 142K according to the image data. The laser beam LB (K) emitted from the semiconductor laser 142K is applied to the rotary polygon mirror 146K via the first reflection mirror 143K and the second reflection mirror 144K, and is deflected and scanned by the rotation polygon mirror 146K. The light is irradiated onto the photosensitive drum 152K of the image forming apparatus 150K through the second reflecting mirror 144K, the third reflecting mirror 148K, and the fourth reflecting mirror 149K.

  The image forming apparatus 150K includes a photosensitive drum 152K as an image carrier that rotates at a predetermined rotation speed in the direction of arrow A, and primary charging as a charging unit that uniformly charges the surface of the photosensitive drum 152K. Scorotron 154K, a developing device 156K for developing the electrostatic latent image formed on the photosensitive drum 152K, a cleaning device 158K, and a rotational position sensor 160K provided to face the surface of the photosensitive drum 152K. And. The photosensitive drum 152K is uniformly charged by the scorotron 154K, and an electrostatic latent image is formed by the laser beam LB (K) irradiated by the optical scanning device 140K. The electrostatic latent image formed on the photosensitive drum 152K is developed with black (K) toner by the developing device 156K and transferred to the intermediate transfer belt 16. Residual toner, paper dust, and the like adhering to the photosensitive drum 152K after the toner image transfer process are removed by the cleaning device 158K. The rotational position sensor 160K detects the rotational position of the photosensitive drum 152K.

  Similarly to the above, the other image forming units 14Y, 14M, and 14C also form yellow (Y), magenta (M), and cyan (C) toner images, and the formed toner images of the respective colors. Transfer to the intermediate transfer belt 16.

  The intermediate transfer belt 16 has a constant tension between the drive roll 164, the first idle roll 165, the steering roll 166, the second idle roll 167, the backup roll 168, and the third idle roll 169. The drive roll 164 is rotationally driven by a drive motor (not shown), and is driven to circulate at a predetermined speed in the direction of arrow A. The intermediate transfer belt 16 is formed into an endless belt by, for example, forming a flexible synthetic resin film such as polyimide in a belt shape and connecting both ends of the synthetic resin film formed in a belt shape by welding or the like. It has been done.

  Further, the intermediate transfer belt 16 has a first primary transfer roll 162K, a second primary transfer roll 162Y, a third primary transfer roll 162M, at positions facing the image forming units 14K, 14Y, 14M, and 14C, respectively. And a fourth primary transfer roll 162C, and the toner images of the respective colors formed on the photosensitive drums 152K, 152Y, 152M, and 152C are transferred onto the intermediate transfer belt 16 in a multiple manner by these primary transfer rolls 162. Is done. The residual toner adhering to the intermediate transfer belt 16 is removed by a cleaning blade or brush of a belt cleaning device 189 provided downstream of the secondary transfer position.

  A surface position sensor 170 is provided to face the surface of the intermediate transfer belt 16 and detects the position of the surface of the intermediate transfer belt 16.

  In the paper transport path 18, a paper feed roller 180 for taking out the recording paper 32 from the paper feed means 17, a first roller pair 181, a second roller pair 182, and a third roller pair 183 for paper transport, A registration roll 184 is provided that conveys the recording paper 32 to the secondary transfer position at a predetermined timing.

  In addition, a secondary transfer roll 185 that is in pressure contact with the backup roll 168 is disposed at the secondary transfer position on the paper transport path 18, and each color toner image transferred onto the intermediate transfer belt 16 is Secondary transfer is performed on the recording paper 32 by the pressing force and electrostatic force of the secondary transfer roll 185. The recording paper 32 onto which the toner image of each color is transferred is conveyed to the fixing device 19 by the first conveyance belt 186 and the second conveyance belt 187.

  The fixing device 19 melts and fixes the toner to the recording paper 32 by performing heat treatment and pressure treatment on the recording paper 32 to which the toner images of the respective colors are transferred.

  Next, the functional configuration of the image processing apparatus 20 will be described. As shown in FIG. 2, the image processing apparatus 20 includes an original image data generation unit 200, an identification information generation unit 202, an original image data storage unit 204, a time direction information generation unit 206, a detection position acquisition unit 208, and a print condition generation unit. 210, information composition unit 212, data output unit 214, image separation unit 216, original image data reading unit 218, unevenness detection unit 220, unevenness correction information generation unit 222, unevenness correction information storage unit 224, input image reception unit 226, color A space conversion unit 228, a correction unit 230, and a data output unit 232 are provided.

  Each of the above components included in the image processing apparatus 20 may be realized in software by a CPU, a memory, a program, or the like, or may be realized in hardware by an ASIC or the like. Further, the image processing apparatus 20 may be included not only in the image forming apparatus 10 but also in a personal computer, for example.

  In the image processing apparatus 20, the original image data generation unit 200 generates correction-only image data as original image data, and outputs the correction-dedicated image data to the identification information generation unit 202, the original image data storage unit 204, and the information synthesis unit 212. When the correction-dedicated image data is input, the identification information generation unit 202 generates identification information for identifying the correction-dedicated image data, and outputs the identification information to the original image data storage unit 204 and the information synthesis unit 212. The original image data storage unit stores the input correction-specific image data and identification information in association with each other.

  The time direction information generation unit 206 generates date information indicating the current date and time when the correction-dedicated image data is to be printed, and direction information indicating the vertical direction of the image represented by the correction-dedicated image data.

  The detection position acquisition unit 208 acquires the rotation position of each photosensitive drum 152 detected by each rotation position sensor 160 and the surface position of the intermediate transfer belt 16 detected by the surface position sensor 170. The printing condition generation unit 210 transfers the toner image from each photosensitive drum 152 to the intermediate transfer belt 16 based on the acquired rotational position of each photosensitive drum 152 and the acquired surface position of the intermediate transfer belt 16. The positional relationship between the rotational position of each photosensitive drum 152 and the surface position of the intermediate transfer belt 16 at the time, and the position of the recording paper 32 and the surface position of the intermediate transfer belt 16 when the toner image is transferred to the recording paper 32 Print condition information indicating the relationship is generated.

  The information synthesizing unit 212 synthesizes identification information, date / time information, direction information, and printing condition information with the correction-dedicated image data, generates synthesized image data, and outputs the synthesized image data to the data output unit 214. The data output unit 214 outputs the input composite image data to the image formation control device 21.

  Further, in the image processing apparatus 20, when the read image data from the image reading unit 12 is input, the image separation unit 216 converts the read image data into correction-dedicated image data, identification information, date / time information, direction information, and print. Separated into condition information, identification information is output to the original image data reading unit 218, correction-only image data and direction information are output to the unevenness detection unit 220, and date / time information and print condition information are output to the unevenness correction information generation unit 222. Output. The image separation unit 216 is an example of the image information acquisition unit of the present invention.

  The original image data reading unit 218 reads the correction-dedicated image data as the original image data stored corresponding to the input identification information from the original image data storage unit 204 and outputs it to the unevenness detection unit 220.

  The unevenness detection unit 220 compares the correction-dedicated image data separated from the read image data with the correction-dedicated image data read as the original image data, detects the unevenness of the image, and detects the detected unevenness. The represented unevenness data is output to the unevenness correction information generation unit 222. At this time, the unevenness detection unit 220 matches the correction-dedicated image data read out as the original image data with the correction-dedicated image data based on the vertical direction indicated by the input direction information, and compares the correction-dedicated image data.

  The unevenness correction information generation unit 222 is configured to cancel each detected unevenness as unevenness correction information for the positional relationship indicated by the printing condition information based on the input unevenness data, date and time information, and printing condition information. The unevenness correction information for converting the pixel value is generated, and the unevenness correction information for the positional relationship indicated by the printing condition information stored in the unevenness correction information storage unit 224 is updated. At this time, the unevenness correction information generation unit 222 generates unevenness correction information that takes into account the variation of unevenness over time based on the date and time indicated by the date and time information and the current date and time. For example, as the date and time indicated by the date and time information is closer to the current date and time, the degree of unevenness that contributes to the generation of the unevenness correction information is increased, and as the date and time indicated by the date and time information is farther from the current date and time, it contributes to the generation of unevenness correction information. Reduce the degree of unevenness. The updated unevenness correction information is used by the correction unit 230 in subsequent image processing. The unevenness correction information storage unit 224 stores unevenness correction information for each positional relationship.

  In addition, when updating the unevenness correction information, the previously generated unevenness correction information may be discarded and updated to newly generated unevenness correction information, or the previously generated unevenness correction information may be updated. The unevenness correction information may be updated according to the newly generated unevenness correction information. At this time, it may be possible to instruct whether to discard the previous unevenness correction information or to update the unevenness correction information according to the previous unevenness correction information by a user operation. The UI device 23 may display whether or not the unevenness correction information is updated, the degree of update of the unevenness correction information, or the update method.

  Note that a conventionally known method may be used as the unevenness detection method, the unevenness correction information generation method, and the unevenness correction method, and detailed description thereof is omitted in this embodiment.

  In the image processing apparatus 20, the input image receiving unit 226 receives input image data from the image reading unit 12 illustrated in FIG. 1 or the user's personal computer, and outputs the input image data to the color space conversion unit 228. The input image data is, for example, an image that is represented by 8 bits for each of RGB and belongs to the sRGB space.

  The color space conversion unit 228 converts the input image (RGB) into a CIELAB (L *, a *, b *) color space (or CIEXYZ) that is a colorimetric value using a predetermined profile (color reproduction characteristics). . In addition, the color space conversion unit 228 converts the converted CIELAB color space image data into image data in the color system YMCK color space suitable for the printing process by using the profile, and outputs the image data to the correction unit 230. Output. Here, the profile is information indicating the color reproduction characteristics of the image, and is, for example, an ICC profile. Note that the color space conversion unit 228 may convert the input RGB color space image into YMCK color space image data using a color conversion table stored in advance.

  The correction unit 230 corrects the input image data to a gradation suitable for the printing process, performs the unevenness correction process, and outputs it to the data output unit 232. More specifically, the correction unit 230 acquires printing condition information regarding the current printing process from the printing condition generation unit 210 and corresponds to the positional relationship indicated by the printing condition information stored in the unevenness correction information storage unit 224. The pixel value of each pixel is converted with reference to the unevenness correction information.

  The data output unit 232 outputs the image data in the YMCK color space input from the correction unit 230 to the image formation control device 21. Since the pixel value of the image data is converted by the correction unit 230, the image formation control device 21 controls the amount of exposure light to the photosensitive drum 152 so as to be suitable for unevenness correction. The data output unit 232 may output the input image data to a memory for storing image data.

  Next, the operation of the image forming apparatus 10 according to the first embodiment will be described.

  First, when the user operates the UI device 23 to instruct the formation of an unevenness correction image, the unevenness correction image print processing routine shown in FIG. 3 is executed in the image processing apparatus 20 of the image forming apparatus 10.

  First, in step 100, correction-dedicated image data is generated, and in step 102, identification information for identifying the correction-dedicated image data generated in step 100 is generated.

  In step 104, date / time information indicating the current date / time and direction information indicating the vertical direction of the correction-only image data are generated. In step 106, the rotational position of each photosensitive drum 152 is acquired from each rotational position sensor 160. At the same time, the surface position of the intermediate transfer belt 16 is acquired from the surface position sensor 170.

  In step 108, the rotational position of each photosensitive drum 152 and the surface position of the intermediate transfer belt 16 are determined based on the rotational position of each photosensitive drum 152 and the surface position of the intermediate transfer belt 16 acquired in step 106. Printing condition information indicating the positional relationship between the recording paper 32 and the surface position of the intermediate transfer belt 16 is generated.

  In the next step 110, the correction-dedicated image data generated in step 100 is added to the identification information generated in step 102, date / time information and direction information generated in step 104, and generated in step 108. The combined print condition information is combined to generate composite image data.

  In step 112, the composite image data generated in step 110 is output to the image formation control device 21 so that the image represented by the composite image data is formed on the recording paper 32. At this time, the image formation control device 21 controls the image formation unit 14 based on the composite image data. For this reason, the amount of light exposed to the photosensitive drum 152 is controlled, and an image represented by the composite image data is formed on the recording paper 32.

  In the next step 114, the correction-dedicated image data generated in step 100 and the identification information generated in step 102 are associated with each other, stored in the original image data storage unit 204, and unevenness correction image printing processing. End the routine.

  Next, the recording paper 32 printed by the unevenness correction image printing processing routine is placed on the platen glass 124 of the image reading unit 12 by the user and the UI device 23 is operated to generate unevenness correction information. 4 is executed in the image processing apparatus 20 of the image forming apparatus 10.

  First, in step 120, composite image data as read image data read by the image reading unit 12 is acquired. In step 122, the combined image data acquired in step 120 is separated into correction-dedicated image data, identification information, date / time information, direction information, and printing condition information.

  In the next step 124, correction-only image data as original image data corresponding to the identification information obtained in step 122 is read from the original image data storage unit 204. In step 126, the direction obtained in step 122 is read. Based on the information, the correction-dedicated image data obtained in step 122 and the correction-dedicated image data read in step 124 are compared in a state where the top and bottom directions are aligned to detect image unevenness.

  In step 128, the image unevenness corresponding to the positional relationship indicated by the printing condition information is canceled based on the image unevenness detected in step 126 and the date / time information and printing condition information obtained in step 122. To generate unevenness correction information. In step 130, the unevenness correction information corresponding to the positional relationship indicated by the printing condition information generated in step 128 is stored in the unevenness correction information storage unit 224, and the unevenness correction information generation processing routine is terminated.

  When the user makes a print request via the personal computer or the image reading unit 12, the input image receiving unit 226 receives the input image data via the network or the image reading unit 12 in the image processing apparatus 20. Acquired and received image data (for example, 8 bits for each of RGB) is output to the color space conversion unit 228.

  Then, the color space conversion unit 228 performs color conversion on the input image data in the RGB color space to the CIELAB color space using the profile, performs predetermined image processing, and then converts the converted CIELAB using the different profile. The color space data is converted into image data in the YMCK color space depending on the output device. The color space conversion unit 228 may color-convert input image data in the RGB color space into image data in the YMCK color space using a color conversion table. The color space conversion unit 228 outputs the image data whose color space has been converted to the correction unit 230.

  Then, the correction unit 230 acquires the printing condition information regarding the current printing process from the printing condition generation unit 210, and the unevenness correction information corresponding to the positional relationship indicated by the printing condition information stored in the unevenness correction information storage unit 224. For example, the color signal is corrected.

  Then, the data output unit 232 outputs the image data input from the correction unit 230 to the image formation control device 21. The image forming control device 21 controls the image forming unit 14 based on the image data. For this reason, the amount of light exposed to the photosensitive drum 152 is controlled, and an image subjected to unevenness correction processing is formed on the recording paper 32.

  As described above, according to the first embodiment, the reader is provided inside the apparatus by acquiring the identification information of the correction-dedicated image data that is the original image data from the read image data. Even if there is not, it is possible to detect the unevenness and generate the unevenness correction information by taking correspondence between the correction-dedicated image data as the original image data and the correction-dedicated image data obtained from the read image.

  In addition, when printing condition information used for unevenness correction is printed on the recording paper together with the correction-dedicated image data and the printed recording paper is read, the printing condition information is acquired, and the positional relationship indicated by the printing condition information It is possible to generate unevenness correction information for correcting unevenness corresponding to.

  Further, if a reading device for reading a document set by the user is provided without providing a reading device in the conveyance path of the recording paper on which the image is formed, the correction-dedicated image data as the original image data is read. It is possible to take correspondence with the correction-dedicated image data obtained from the image.

  The actual image data to be actually printed is printed by printing correction-dedicated image data used exclusively for unevenness correction on a recording sheet, reading the recording sheet on which the correction-dedicated image data is printed, and generating unevenness correction information. Compared to the case where unevenness is detected by reading a printed recording sheet, more or more accurate unevenness correction can be performed with one image.

  Next, a second embodiment will be described. Since the configuration of the image forming system according to the second embodiment is the same as that of the first embodiment, the same reference numerals are given and the description thereof is omitted.

  In the second embodiment, the apparatus information for identifying the image forming apparatus is combined with the correction-dedicated image data, and the unevenness correction information is generated according to the apparatus information. This is mainly different from the first embodiment.

  In the image forming apparatus 10 according to the second embodiment, the image processing apparatus 20 generates apparatus information for identifying the image forming apparatus, and the information combining unit 212 performs correction-specific image data, identification information, The date / time information, the direction information, the printing condition information, and the device information are combined to generate combined image data, which is output to the data output unit 214.

  Further, in the image processing device 20, the image separation unit 216 uses the corrected image data, identification information, date and time information, direction information, printing condition information, and device information from the composite image data that is the read image data. , And whether the obtained device information matches the device information of its own device. If they do not match, reading by the original image data reading unit 218, detection of unevenness by the unevenness detection unit 220, And the unevenness correction information by the unevenness correction information generation unit 222 is stopped.

  Note that the other configuration of the image forming apparatus 10 according to the second embodiment is the same as that of the first embodiment, and a description thereof will be omitted.

  Next, the unevenness correction information generation processing routine according to the second embodiment will be described with reference to FIG. In addition, about the process similar to 1st Embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

  First, in step 120, composite image data as read image data read by the image reading unit 12 is acquired. In step 122, the combined image data acquired in step 120 is separated into correction-dedicated image data, identification information, date / time information, direction information, printing condition information, and apparatus information.

  Then, in step 200, it is determined whether or not the device information obtained in step 122 matches the device information indicating the own device. The correction information generation processing routine ends. On the other hand, if the device information matches, the process proceeds to step 124.

  In step 124, the correction-dedicated image data corresponding to the identification information obtained in step 122 is read from the original image data storage unit 204, and in step 126, image unevenness is detected. Then, in step 128, unevenness correction information is generated, and in step 130, the unevenness correction information generated in step 128 is stored in the unevenness correction information storage unit 224, and the unevenness correction information generation processing routine ends.

  Since other operations of the image forming apparatus according to the second embodiment are the same as those of the first embodiment, description thereof is omitted.

  As described above, when the device information obtained from the read image data is not the device information of the own device, it is possible to cancel the generation of the unevenness correction information by taking the correspondence with the correction-dedicated image data.

  In the first embodiment and the second embodiment described above, the case where the identification information, the printing condition information, and the like are printed as they are has been described as an example. However, the present invention is not limited to this. An index (for example, a bar code) indicating “” may be printed. In this case, the correspondence relationship between the index and information such as identification information and printing condition information is stored in advance, and the identification information and printing condition information corresponding to the index are obtained from the index obtained from the read image data. What is necessary is just to acquire information.

  Next, a third embodiment will be described. In addition, about the part which becomes the structure similar to 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  In the third embodiment, various types of information such as identification information are combined with actual image data such as image data input for image formation and read image data for copying, and an image is recorded on a recording sheet. Is different from the first embodiment mainly in that various information is represented by an invisible pattern.

  As shown in FIG. 6, the image processing apparatus 350 of the image forming apparatus according to the third embodiment includes an input image receiving unit 300, an identification information generating unit 202, a composite area extracting unit 302, an original image data accumulating unit 204, Time direction information generation unit 206, detection position acquisition unit 208, print condition generation unit 210, information synthesis unit 312, data output unit 214, image separation unit 316, original image data reading unit 218, unevenness detection unit 220, unevenness correction information generation Unit 222, unevenness correction information storage unit 224, input image reception unit 226, color space conversion unit 228, correction unit 230, and data output unit 232.

  In the image processing apparatus 350, the input image receiving unit 300 receives input image data from the original image data from the image reading unit 12 or the user's personal computer when the formation of the unevenness correction image is instructed, and the identification information. The data is output to the generation unit 202, the synthesis area extraction unit 302, the original image data storage unit 204, and the information synthesis unit 212.

  The synthesis region extraction unit 302 performs spatial frequency analysis of the input image data, and extracts a region having a spatial frequency other than the spatial frequency of the unevenness region as illustrated in FIG. 7 as a synthesis region of various information. . For example, an edge portion of the image, a fine texture area, and the like are extracted as a synthesis area.

  The information synthesis unit 312 converts each of the identification information, date / time information, direction information, and printing condition information into an invisible pattern such as a digital watermark, and synthesizes the input image data and the converted invisible pattern, Composite image data is generated and output to the data output unit 214.

  In the image processing apparatus 350, when the read image data from the image reading unit 12 is input, the image separation unit 316 converts the read image data into real image data, identification information, date / time information, direction information, and print data. While separating into invisible patterns representing each of the condition information, the invisible patterns are converted into identification information, date / time information, direction information, and printing condition information. The image separation unit 316 outputs identification information to the original image data reading unit 218, outputs image data and direction information to the unevenness detection unit 220, and outputs date information and print condition information to the unevenness correction information generation unit 222. To do.

  The unevenness detection unit 220 compares the actual image data separated from the read image data with the image data read as the original image data, detects unevenness in the image, and displays unevenness data representing the detected unevenness. Is output to the unevenness correction information generation unit 222.

  Next, in the image forming apparatus according to the third embodiment, when the user issues a print request via the personal computer or the image reading unit 12 and instructs the formation of the unevenness correction image, the image of the image forming apparatus 10 is displayed. In the processing device 350, a non-uniformity correction image printing processing routine is executed as described below.

  First, input image data is acquired via the personal computer or the image reading unit 12, and identification information for identifying the acquired input image data is generated.

  Then, spatial frequency analysis is performed on the input image data, and a region having a spatial frequency other than the spatial frequency of the uneven region is extracted as a synthesis region.

  In addition, date / time information indicating the current date / time and direction information indicating the vertical direction of the correction-dedicated image data are generated, and the rotational position of each photosensitive drum 152 is acquired, and the surface position of the intermediate transfer belt 16 is acquired.

  Then, based on the acquired rotational position of each photosensitive drum 152 and the surface position of the intermediate transfer belt 16, the positional relationship between the rotational position of each photosensitive drum 152 and the surface position of the intermediate transfer belt 16, and the recording paper 32. Print condition information indicating the positional relationship between the intermediate transfer belt 16 and the surface position of the intermediate transfer belt 16 is generated. Next, each of the generated identification information, the generated date / time information and direction information, and the generated printing condition information is converted into an invisible pattern, and the converted invisible pattern is synthesized with the input image data. To generate composite image data.

  Then, the generated composite image data is output to the image formation control device 21, and the image represented by the composite image data is printed on the recording paper 32. Further, the input image data and the generated identification information are associated with each other and stored in the original image data storage unit 204, and the unevenness correction image printing processing routine is ended.

  Note that other configurations and operations of the image forming apparatus according to the third embodiment are the same as those of the first embodiment, and thus description thereof is omitted.

  As described above, according to the third embodiment, the identification information of the actual image data that is the original image data is obtained from the read image data, so that no reading device is provided inside the device. Even in this case, it is possible to detect unevenness and generate unevenness correction information by taking correspondence between actual image data as original image data and image data obtained from the read image.

  In addition, when printing information such as printing condition information used for unevenness correction is printed on a recording sheet together with actual image data, and the printed recording sheet is read, the printing condition information is acquired and the position indicated by the printing condition information Unevenness correction information for correcting unevenness corresponding to the relationship can be generated.

  In the first to third embodiments, the original image data and the information such as the identification information have been described as an example of printing on the recording paper with the same toner. However, the present invention is not limited, and information such as identification information may be printed on recording paper using ink different from toner. For example, information such as identification information may be printed on a recording sheet using a transparent infrared absorbing ink, and the information such as identification information printed on the recording sheet may be read by an infrared camera.

  Further, the case where the direction information indicates the top and bottom direction of the image data has been described as an example. However, the present invention is not limited to this, and the direction information indicates another direction of the image data, for example, the horizontal direction. May be.

  In addition, the case where the date / time information indicates the date / time when the image formation by the original image data is performed has been described as an example, but the present invention is not limited to this. Only the date when it was performed may be shown.

  Moreover, although the case where the identification information, the printing condition information, the date information, the direction information, and the device information are combined with the original image data has been described as an example, the present invention is not limited to this. Thus, only the identification information may be combined, or the identification information and at least one of the printing condition information, date / time information, direction information, and device information may be combined with the original image data. Also good.

  In addition, the case where image formation based on synthesized image data in which information such as identification information is synthesized when an instruction to form an image for unevenness correction is instructed by a user operation has been described as an example. Rather than using a composite image data that combines information such as identification information when a certain amount of time has elapsed or when the number of printed sheets has reached a certain number An image may be formed. In this case, the user may be prompted to operate the reading unit to instruct generation of unevenness correction information.

  Further, a method of printing various information such as the identification information on a recording sheet with an invisible pattern may be applied to the first embodiment or the second embodiment.

1 is a schematic diagram illustrating a configuration of an image forming apparatus according to a first embodiment of the present invention. 1 is a block diagram illustrating a configuration of an image processing apparatus in an image forming apparatus according to a first embodiment of the present invention. 3 is a flowchart showing the contents of a non-uniformity correction image print processing routine in the image processing apparatus of the image forming apparatus according to the first embodiment of the present invention. 3 is a flowchart showing the contents of a non-uniformity correction information generation processing routine in the image processing apparatus of the image forming apparatus according to the first embodiment of the present invention. 10 is a flowchart showing the contents of a non-uniformity correction information generation processing routine in the image processing apparatus of the image forming apparatus according to the second embodiment of the present invention. It is a block diagram which shows the structure of the image processing apparatus in the image forming apparatus which concerns on the 3rd Embodiment of this invention. It is a graph which shows the example of the spatial frequency of a nonuniformity area.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 12 Image reading unit 14 Image forming unit 16 Intermediate transfer belts 20 and 350 Image processing apparatus 21 Image forming control apparatus 30 Document 32 Recording paper 152 Photosensitive drum 156 Developer 160 Rotational position sensor 170 Surface position sensor 200 Original image Data generation unit 202 Identification information generation unit 204 Original image data storage unit 206 Time direction information generation unit 208 Detection position acquisition unit 210 Print condition generation unit 212, 312 Information composition unit 216, 316 Image separation unit 218 Original image data read unit 220 Unevenness Detection unit 222 Unevenness correction information generation unit 230 Correction unit 302 Composite region extraction unit

Claims (5)

A combining unit that combines the image information to be image formed with the identification information for identifying the image information, and generates combined image information;
Image forming means for forming an image represented by the synthesized image information synthesized by the synthesizing means on a recording medium;
Image storage means for storing the image information and the identification information correspondingly;
Image reading means for reading an image formed on the recording medium;
Image information acquisition means for acquiring the image information and the identification information from the composite image information of the image read by the image reading means;
Image reading means for reading out the image information corresponding to the acquired identification information from the image storage means;
Unevenness detecting means for detecting unevenness of an image based on the acquired image information and the image information read by the image reading means;
Unevenness correction information generating means for generating unevenness correction information for correcting unevenness based on the unevenness of the image detected by the unevenness detecting means;
An image forming apparatus including: The image forming means includes: a rotatable image holding body; a latent image forming means for forming a latent image on the surface of the image holding body based on the composite image information; A developing means for developing the image, and a transfer means for transferring the developed image to a recording medium,
Position detection means for detecting a positional relationship between the recording medium and the rotational position of the image carrier,
The synthesizing unit synthesizes the image information, identification information of the image information, and positional relationship information indicating the positional relationship detected by the position detecting unit to generate the synthesized image information,
The image information acquisition unit acquires the image information, the identification information, and the positional relationship information from the composite image information of the image read by the image reading unit,
2. The unevenness correction information for correcting unevenness with respect to the positional relationship indicated by the acquired positional relationship information based on the unevenness of the image detected by the unevenness detecting unit. Image forming apparatus. The synthesizing unit synthesizes the image information, identification information of the image information, and date / time information indicating a current date or date / time to generate the synthesized image information,
The image information acquisition unit acquires the image information, the identification information, and the date / time information from the composite image information of the image read by the image reading unit,
The correction information generation unit generates the unevenness correction information based on the unevenness of the image detected by the unevenness detection unit, the acquired date / time information, and a current date or date / time. Image forming apparatus. The synthesizing unit synthesizes the image information, identification information of the image information, and direction information indicating a predetermined direction of the image information to generate the synthesized image information,
The image information acquisition unit acquires the image information, the identification information, and the direction information from the composite image information of the image read by the image reading unit,
The unevenness detecting means associates the acquired image information and the image information read by the image reading means with a predetermined direction indicated by the direction information based on the acquired direction information. The image forming apparatus according to claim 1, wherein unevenness of the image is detected. The synthesizing unit synthesizes the image information, identification information of the image information, and device information for identifying the own device, and generates the synthesized image information.
The image information acquisition unit acquires the image information, the identification information, and the device information from the composite image information of the image read by the image reading unit,
The image forming apparatus according to claim 1, wherein the unevenness correction information generation unit does not generate the unevenness correction information when the acquired device information is not device information of the own device.

Images