JP2008173868A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform image formation of a sample image by using image data of a page suitable for confirming the image quality when the image formation of the sample image is performed by the job image data during image formation of the image data of the job. <P>SOLUTION: An image forming apparatus 1 includes a printer part 40, a compression IC 150, and a controlling part 110. The printer part 40 selects the sample image data for the sample image among the image data of page units of the job and forms the image of the sample image by the sample image data selected. The compression IC 150 compresses the image data of the page units. The controlling part 110 judges whether the image data size after compression by the compression part of the sample image data selected is at least a specified value or not, and when the image data size after compression is not the specified value or larger, the selected sample image data are changed to the image data of other page unit, and the image formation of the sample image is performed by using the changed image data of the other page unit as the sample image data. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus.

  2. Description of the Related Art Conventionally, some image forming apparatuses that form an image on a sheet include a stacker for stacking sheets on which images have been formed. This stacker has a capability of stacking a large amount (for example, about 5000 sheets) of paper on which images have been formed. The stacked paper sheets are stacked on the stacker with the door closed, and the stacked paper sheets are removed with the door open.

  That is, in the image forming apparatus, when the sheets on which images have been formed are stacked on the stacker, the images on the sheets cannot be visually confirmed. Thus, for example, if defective printing occurs due to density reduction or smearing from about 3000 sheets during continuous printing of 5000 sheets, the latter 2000 sheets are discarded, and the image forming time and resources for that amount are discarded. Was wasted. Further, when checking the paper stacked in the stacker during the continuous printing, it is necessary to temporarily interrupt the image forming process, resulting in a reduction in work efficiency.

For this reason, some image forming apparatuses print a sample image during continuous printing, and output the sample image to a sub-tray that can be visually recognized from the outside, thereby confirming it visually. For example, Patent Document 1 discloses a technique related to a color printer that outputs a sample image based on a set execution cycle of the sample image. Patent Document 2 discloses a technique for outputting a sample image to a sub-tray when a sample image is printed using a page image being continuously printed while stacking continuously printed sheets on a stacker. It is disclosed.
JP-A-8-197779 JP 2005-153374 A

  However, in the above-described conventional technology, the sample image can be visually observed during the continuous image formation. However, when the sample image is formed using the image data during the continuous image formation, the sample image is formed. For this reason, when the selected page image data is a blank page or a solid black page, it has not been possible to confirm deterioration of image quality or density reduction from the sample image formed.

  The present invention has been made in view of the above-described problems of the prior art, and is suitable for confirming image quality when a sample image is formed by job image data during image formation of a job. Another object of the present invention is to provide an image forming apparatus for forming an image of a sample image with image data of a page.

In order to solve the above problem, the invention according to claim 1 selects sample image data for a sample image from image data in units of pages of a job, and images a sample image by the selected sample image data. In an image forming apparatus having a printer unit to form,
A compression unit that compresses the image data in units of pages;
It is determined whether the image data size after compression by the compression unit of the selected sample image data is greater than or equal to a predetermined value, and when the image data size after compression is not greater than or equal to a predetermined value, the selected sample image It has a control part which changes data into image data of other page units, and performs image formation of a sample image by using the changed image data of other page units as sample image data.

  According to a second aspect of the present invention, in the first aspect of the invention, the other page unit image data to be changed is image data of the next page of the page unit image data of the selected job. It is characterized by that.

  According to a third aspect of the present invention, in the first aspect of the present invention, the image data size after compression is different from the image data of the page unit of the job. The image data has the largest image data size.

  According to the first aspect of the present invention, when the sample image is formed from the image data of the page unit of the job, the sample is sampled with the image data determined based on the data size after compression of the image data of the page unit. An image can be formed, and a sample image suitable for confirmation of image quality by an image having a large amount of information can be formed.

  According to the second aspect of the present invention, the image quality can be confirmed with an appropriate sample image by excluding the blank image and the thin image that are difficult to confirm as the sample image.

  According to the third aspect of the present invention, the image quality can be confirmed as an image having a large amount of information for image quality confirmation as a sample image, and the accuracy of the image quality confirmation is improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments. The embodiment of the present invention shows the most preferable mode of the invention, and the scope of the invention is not limited to this.

  First, the features of the apparatus of the present embodiment will be described with reference to FIGS. FIG. 1 is a conceptual diagram illustrating the configuration of the image forming apparatus 1. FIG. 2 is a block diagram schematically illustrating a functional configuration of the image forming apparatus 1.

  First, the outline of the configuration of the image forming apparatus 1 will be described. As shown in FIG. 1, the image forming apparatus 1 includes an image reading unit 20, an operation display unit 30, a printer unit 40, a paper feed unit 50, and a post-processing unit 60.

  The image reading unit 20 includes an ADF unit 21 (Auto Document Feeder) that is an automatic document feeder, and a scanner unit 22. The ADF unit 21 conveys the document placed on the document table. The scanner unit 22 optically scans the document transported by 21 through the contact glass or optically scans the document placed on the platen glass, and performs photoelectric scanning with a CCD image sensor 23 (Charge-Coupled Devices). Conversion is performed to read an image of a document, and image data is acquired.

  The image data read by the image reading unit 20 is subjected to various types of image processing by the control unit 110 described later, and is output to the printer unit 40 as image data for image formation.

  The operation display unit 30 includes various function keys such as a numeric button, a start key for instructing start of image formation, and a utility key. The operation display unit 30 receives user input and outputs the input information to the control unit 110. The operation display unit 30 includes an LCD 31 (Liquid Crystal Display), and a touch panel that accepts touch input on the screen is configured on the LCD 31, and displays various operation screens such as a setting condition setting screen and various processing results.

  The printer unit 40 performs electrophotographic image formation. The printer unit 40 transports a sheet fed from the sheet feeding unit 50, an image forming unit 42 that forms an image on the sheet, and a sheet on the sheet. And a fixing unit 43 that fixes the formed toner image.

  The image forming unit 42 includes a photosensitive drum as an image carrier, a charging unit that charges the photosensitive drum, an exposure unit such as an LD (LASER Diode) that performs exposure scanning on the surface of the photosensitive drum based on image data, and a photosensitive unit. A developing unit that develops the electrostatic latent image on the drum, a transfer unit that transfers the toner image formed on the photosensitive drum to a sheet, and a cleaning unit that removes residual toner on the photosensitive drum. The

  In the present embodiment, the printer unit 40 performs image formation by the electrophotographic method. However, the present invention is not limited to this, and other image forming methods such as an inkjet method, a thermal transfer method, a dot impact method, and the like. It is good.

  The paper feed unit 50 includes four paper feed trays 51 to 54. In the present embodiment, the four paper feed trays are provided. However, the present invention is not limited to this, and the number is not particularly limited. Each of the paper feed trays 51 to 54 can store paper of different paper types and sizes, such as plain paper, back paper, recycled paper, and high-quality paper.

  The post-processing unit 60 performs various types of post-processing such as sorting processing, punching (punching) processing, stapling processing, half-folding processing, cutting processing, and the like on the paper on which the image is formed by the printer unit 40 under the control of a post-processing control unit described later. Various post-processing units (not shown in particular) that perform processing and a transport unit 62 that transports post-processed paper to an output destination.

  The post-processing unit 60 also stacks about 5000 sheets as a discharge destination of the transport unit 62, and a stacker 63 capable of taking out the stacked sheets with an open / close door, and easily confirms the discharged sheets from the outside. The configuration includes a sub-tray 64 as a possible paper discharge tray, a main tray 65 as a paper discharge tray that can be sorted and output by changing the paper discharge position for each unit under the control of the post-processing control unit. is there.

  Next, the functional configuration of the image forming apparatus 1 will be described. As shown in FIG. 2, the image forming apparatus 1 includes a control board 100, a printer controller 10, an image reading unit 20, an operation display unit 30, a printer unit 40, a post-processing unit 60, and an HDD 70 (Hard Disk Drive).

  The printer controller 10 includes a controller control unit 11, a DRAM control IC 12 (Integrated Circuit), an image memory 13, a communication control unit 14, and a NIC 15 (Network Interface Card).

  The controller control unit 11 comprehensively controls the operation of each unit, and outputs data such as image data output from a user terminal PC (Personal Computer) on a LAN (Local Area Network) via the communication control unit 14 and the NIC 15. Is distributed to the DRAM control IC 160 as a job.

  The DRAM control IC 12 controls the storage of output data received by the NIC 15 and the communication control unit 14 in the image memory 13 and the reading of output data from the image memory 13. The DRAM control IC 12 is connected to the DRAM control IC 160 via a PCI (Peripheral Components Interconnect) bus, and reads output data to be printed from the image memory 13 and outputs it to the DRAM control IC 160 in accordance with an instruction from the controller control unit 11. To do.

  The image memory 13 is composed of DRAM (Dynamic Random Access Memory), and temporarily stores input output data.

  The communication control unit 14 controls communication of the NIC 15. The NIC 15 is a communication interface for connecting to a LAN, and receives output data to be printed from the user terminal PC via the LAN. The received output data is output to the DRAM control IC 12.

  The image reading unit 20 includes the ADF unit 21 illustrated in FIG. 1, a scanner unit 22 having a CCD image sensor 23, and an image reading control unit 24. The image reading control unit 24 controls the ADF unit 21 and the scanner unit 22 according to an instruction from the control unit 110 to execute optical scanning of the document surface, and outputs the read analog image signal to the reading processing unit 140.

  The operation display unit 30 includes a touch panel configured integrally with an LCD 31 serving as a display unit, various function keys (not shown), and an operation display control unit 32. The operation display control unit 32 outputs operation signals operated by various function keys or a touch panel to the control unit 110. In addition, the operation display control unit 32 displays various operation screens, various processing results, and the like on the LCD 31 in accordance with instructions from the control unit 110.

  The printer unit 40 includes various units related to image formation, such as the image forming unit 42, and a printer control unit 44. The printer control unit 44 controls the operation of each unit of the printer unit 40 in accordance with an instruction from the control unit 110 and causes the image forming unit 42 and the like to form an image based on the image data input from the writing processing unit 190.

  The post-processing unit 60 includes various post-processing units (not shown), a post-processing control unit 61, a transport unit 62, a stacker 63, and a sub-tray 64. The post-processing control unit 61 controls various post-processing units so as to perform various post-processings on the image-formed paper output from the printer unit 40 in accordance with instructions from the control unit 110. In addition, the post-processing control unit 61 controls the transport unit 62 so as to change the output destination of the post-processed paper to the stacker 63 or the sub-tray 64 in accordance with an instruction from the control unit 110.

  The HDD 70 stores information in a readable and writable manner. The HDD 70 stores compressed image data compressed by the compression IC 150 as will be described later.

  The control board 100 includes a control unit 110, a nonvolatile memory 120, a RAM 130 (Random Access Memory), a read processing unit 140, a compression IC 150, a DRAM control IC 160, an image memory 170, a decompression IC 180, and a write processing unit. 190 and a watch IC 200.

  The control unit 110 includes a CPU (Central Processing Unit) and the like, and centrally controls each unit of the image forming apparatus 1. The control unit 110 reads a specified program or data from the system program, various application programs, and setting information stored in the non-volatile memory 120, expands it in the RAM 130, and cooperates with the program expanded in the RAM 130. Various processes are executed.

  The control unit 110 also controls the HDD 70 to store the compressed image data compressed by the compression IC 150 and the compressed image data stored in the image memory 170.

  The nonvolatile memory 120 is configured by a flash memory or the like, and stores various programs and data in a rewritable manner. For example, the nonvolatile memory 120 stores a counter that counts the number of sheets on which images have been formed. The nonvolatile memory 120 stores data such as a threshold for determining the compression rate of the compressed image data compressed by the compression IC 150 described later and stored in the compression memory 171 or the data size of the compressed image data.

  The reading processing unit 140 performs various processes such as analog processing, A / D conversion processing, and shading processing on the analog image signal input from the image reading control unit 24 of the image reading unit 20 to generate digital image data. The generated digital image data is output to the compression IC 150.

  The compression IC 150 performs a compression process on the digital image data input from the reading processing unit 140 or the printer controller 10 and outputs the digital image data to the DRAM control IC 160. This compression of image data is performed by using a known encoding technique such as entropy code, universal code, non-universal code, differential prediction code, and fractal code for the value of each pixel in the image data and its redundant part. It is to convert to a data size shorter than the size.

  For example, if the data of six pixels is represented by the character string “black black black black black black”, the meaning is maintained by replacing it with the symbol “black 6” meaning “there are six blacks”. As it is, 6 characters can be changed to 2 characters, and the data size can be compressed to 1/3.

  That is, in the compression processing in the compression IC 150, when the image before compression is monotonous, that is, when there is no variation in data for each pixel, the compression rate (compression efficiency) by encoding is high (image data after compression). Amount / image data amount before compression is low). Conversely, when the image before compression is complicated, that is, when the data for each pixel varies or the data for each pixel is dense, the compression rate is low (the amount of compressed image data / compression The value of the previous image data amount becomes high).

  Similarly, when page image data of the same size is compressed by the compression IC 150, the data size for each page image data decreases when the page image is monotonous and increases when it is complicated. That is, the image data (compressed image data) after being compressed by the compression IC 150 differs in the compression rate and the data size of the image data per page depending on the complexity of the image.

  Thus, it can be seen that the smaller the data size after compression, the more monotonous the image data before compression. That the image data is monotonous means that there is little image quality information and it is not suitable for visual confirmation as a sample image. By comparing the data size of the compressed image data with other image data, it is possible to determine whether the image data for the sample image is appropriate as the sample image.

  As a specific example of compressed image data, an image is divided into blocks of a fixed size (8 × 8 pixels), discrete cosine transform (DCT) is performed for each block, and the converted data is quantized. Then, JPEG (Joint Photographic Experts Group) which performs entropy coding by Huffman code and compresses it is available. Although not specifically listed, the compressed image data in the compression IC 150 may be other than JPEG as long as it is a compression format in which the compression rate and the data size per page differ depending on the degree of complexity of the image as described above. .

  The DRAM control IC 160 controls the compression processing of the digital image data by the compression IC 150 and the decompression processing of the compressed image data by the decompression IC 180 in accordance with an instruction from the control unit 110, and performs input / output control of image data to the image memory 170. . For example, when an instruction to store an analog image signal read by the image reading unit 20 is given, the compression processing of the digital image data input from the reading processing unit 140 is executed by the compression IC 150, and the compressed image data is stored in the image memory 170. Stored in the compression memory 171.

  Further, when the print control of the compressed image data stored in the compression memory 171 is instructed, the DRAM control IC 160 reads the compressed image data from the compression memory 171, performs decompression processing by the decompression IC 180, and stores it in the page memory 172. . Further, when an instruction to print out the uncompressed image data stored in the page memory 172 is given, the uncompressed image data is read from the page memory 172 and output to the write processing unit 190.

  The image memory 170 includes a compression memory 171 such as a DRAM and a page memory 172. The compression memory 171 is a memory for storing compressed image data. The page memory 172 is a memory for temporarily storing uncompressed image data to be printed before printing.

  The decompression IC 180 performs decompression processing on the input compressed image data. The writing processing unit 190 generates print data for image formation based on the uncompressed image data input from the DRAM control IC 160 and outputs the print data to the printer unit 40 (image forming unit 42).

  The clock IC 200 counts date information such as date and time, acquires date information at the time of the request, and outputs it to the control unit 110 in response to a request from the control unit 110.

  Next, operations performed by the control unit 110 of the image forming apparatus 1 will be described with reference to FIGS. FIG. 3 is a flowchart showing the operation of the image forming apparatus 1. FIG. 4 is a conceptual diagram illustrating a setting screen of the image forming apparatus 1. FIG. 5 is a flowchart showing the paper feed process of the image forming apparatus 1. FIG. 6A is a flowchart showing the image forming process of the image forming apparatus 1, and FIG. 6B is a flowchart showing the next page image forming process of the image forming apparatus 1. FIG. 7 is a flowchart showing the paper discharge process of the image forming apparatus 1. FIG. 8A is a conceptual diagram illustrating output of a sample image, and FIG. 8B is a conceptual diagram illustrating output of a sample image with image data of the next page.

  As shown in FIG. 3, the control unit 110 receives an operation instruction from the operation display unit 30 or the like, and performs a setting process for performing various settings such as an image forming condition (step S1). Next, the image data read by the image reading unit 20, the image forming instruction from the operation display unit 30, job information including image data to be formed input from the user terminal PC via the printer controller 10, and the like are received. The input image data is compressed by the compression IC 150 and stored in the compression memory 171 and an image formation start process for warming up the printer unit 40 is executed (step S2).

  In the setting process in step S1, a sample output setting screen G as shown in FIG. 4 is displayed on the LCD 31, and an input of a setting value is accepted based on an operation from the touch panel of the operation display unit 30. The sample output setting screen G forms an image of a sample image when an image is formed on a predetermined number of sheets, and forms a sample image when a predetermined time has elapsed since the previous image formation of the sample image. This is a setting screen for performing mode setting relating to image formation of a sample image such as performing or outputting a sample at a predetermined time.

  The sample output setting screen G has a screen configuration including a mode setting region G1, a cycle setting region G2, and a recovery setting region G3. The mode setting area G1 is an area for selecting and setting the above-described mode. The period setting area G2 is an area for setting the number of sheets and the period in the mode set in the mode setting area G1. The recovery setting area G3 determines whether or not to perform recovery with another image data when the image data of the sample job is not suitable for the image formation of the sample image when the image data of the job being executed is formed. This is an area for setting. By referring to the sample output setting screen G, the user can make various settings relating to sample image output.

  Here, a case where a mode for outputting a sample image when an image is formed on a predetermined number of sheets in step S1 will be described.

  Following step S2, the control unit 110 sequentially decompresses the image data stored in the compression memory 171 using the decompression IC 180 based on the image formation instruction and job information received in step S2, and stores the image data in the page memory 172. Paper feed processing for feeding the paper stacked on the paper feed unit 50 and transporting it to the printer unit 40 until the job for image formation based on the page image data is completed (step S6: YES) (step S3). The image forming process (step S3) for forming an image on the paper conveyed to the printer unit 40, and the paper after the image formation is discharged to the stacker 63, sub-tray 64, main tray 65, etc. of the post-processing unit 60 The process (step S4) is sequentially performed for each page.

  Here, details of the paper feed process (step S3) performed by the control unit 110 by controlling the paper feed unit 50 will be described. As shown in FIG. 5, the control unit 110 uses the value of the sample output counter, which is a number counter for performing sample output for every predetermined number of sheets set in the RAM 130, and the set value set in step S1. By comparing, it is determined whether or not it is time to output the sample image (step S31).

  When a mode is set in step S1, such as forming a sample image when a predetermined time elapses from the previous sample image formation, or forming a sample image at a predetermined time. In step S31, determination is made as to whether or not it is time to form an image of the sample image based on the time information when the previous sample image was formed in the RAM 130 and the current time acquired from the clock IC 200. Is done.

  If it is not time to form the sample image in step S31 (NO), the control unit 110 acquires information (paper size, paper discharge destination, etc.) regarding the page to be fed from the image forming job (step S32). Based on the acquired information, paper discharge destination information regarding the page to be fed is set (step S33), and the above-described sample output counter is incremented (step S34).

  In step S31, when it is time to form a sample image (YES), the control unit 110 acquires information related to the page to be fed as in step S32 (step S35), and performs normal image formation. The job to be performed is temporarily stopped, the sample image output is set in the RAM 130 or the like (step S36), and the sample output counter is cleared (step S37). That is, the control unit 110 sets the page image data at the time of the temporary suspension in step S36 in the job as sample image data.

  Subsequent to steps S34 and S37, the control unit 110 issues a paper feed request to the paper feed unit 50 to feed paper from a paper feed tray that stores paper of a paper size based on the information acquired in step S32. (Step S38), the paper is conveyed to the printer unit 40, and the paper feed process is terminated.

  As described above, in the paper feed process for each page, it is determined whether or not it is the sample image output timing when each page is fed, and the normal paper feed process (steps S32 to S34) is performed based on the determination. , S38), or a paper feed process (steps S35 to S38) in which the job is temporarily suspended and the sample image output is set.

  Next, details of the image forming process (step S4) performed by the control unit 110 by controlling the printer unit 40 will be described. As shown in FIG. 6A, when the image forming process is started, the control unit 110 determines whether or not the sample image output is set (step S41).

  When sample image output is set in step S41, the control unit 110 sets the data size of the compressed image data stored in the compression memory 171 that is the current page image data to be processed and the nonvolatile memory 120. It is determined whether or not the data size is a predetermined value or more, that is, whether or not the image data is a complex image suitable for sample image output (step S42).

  When the sample image output is not set (step S41: NO), or when the control unit 110 determines that the data size is equal to or larger than a predetermined value and the page image data is image data suitable for sample image output ( (Step S42: YES), the compressed image data stored in the current compression memory 171 to be processed is decompressed by the decompression IC 180 and output to the printer unit 40, the image is formed on the paper (step S43), and the process ends. If the data size is less than the predetermined value and the page image data is not suitable for sample image output (step S42: NO), the control unit 110 performs the next page image forming process (step S44), and performs the image forming process. finish.

  Here, details of the next page image forming process performed by the control unit 110 will be described. As shown in FIG. 6A, when the next page image forming process is started, the control unit 110 determines whether or not there is a next page in the currently executed job (step S441).

  When there is a next page in step S441 (YES), similarly to step S42, the control unit 110 stores the compressed image data stored in the compression memory 171 that is the page image data of the next page with a data size greater than or equal to a predetermined value. It is determined whether or not there is (step S442). If the compressed image data of the next page has a data size less than the predetermined value (NO), the number of pages is incremented (step S443), and the process proceeds to the next page. If the compressed image data of the next page has a data size greater than or equal to a predetermined value (YES), the compressed image data of the next page is decompressed by the decompression IC 180 and output to the printer unit 40 to form an image on paper (step) S444), the image forming process is terminated.

  If there is no next page in step S441 (NO), the control unit 110 selects compressed image data having the maximum data size among all the compressed image data stored in the compression memory 171 that is page image data related to the job. The image is selected and decompressed by the decompression IC 180 and output to the printer unit 40 to form an image on a sheet (step S445), and the image forming process is terminated.

  As described above, in the image forming process in units of pages, it is determined whether or not the sample image output is set when the image is formed for each page. If the sample image output is not set, normal image formation is performed. If set, it is determined whether the page image data is suitable for sample image output based on the data size of the compressed image data related to the page image data to be processed, and is suitable for image formation of the sample image The processing configuration performs image formation with the page image data.

  Further, in the page-by-page image forming process, when the page image data to be processed is not suitable for the image formation of the sample image, the next page image forming process is performed, and the page image data of the next page is suitable for the sample image output. This is a processing configuration for sequentially determining whether or not to form an image with page image data suitable for sample image output after the page image data to be processed. If there is no page image data suitable for sample image output after the page image data to be processed, the data size after compression is the largest among all page image data related to the job, and it is suitable for sample image output. This is a processing configuration for performing image formation with page image data.

  Next, details of the paper discharge process (step S5) performed by the control unit 110 by controlling the post-processing unit 60 will be described. As shown in FIG. 7, when the paper discharge process is started, the control unit 110 determines whether or not sample image output is set (step S51).

  When the sample image output is not set in step S51 (NO), the control unit 110 outputs the sheet after image formation output from the printer unit 40 based on information such as the paper discharge destination acquired from the image formation job. After the post-processing, an instruction to discharge the paper to the stacker 63 and the main tray 65 is output to the post-processing unit 60, the normal paper discharge process is executed (step S52), and the paper discharge process is terminated.

  When the sample image output is set in step S51 (YES), the control unit 110 performs post-processing on an instruction to discharge the image-formed paper output from the printer unit 40 based on the sample output setting to the sub-tray 64. Output to the unit 60 and execute a paper discharge process for discharging the sample image (step S53), clear the sample image output setting set in the RAM 130 and the like, and restart the job (step S54). The paper discharge process is terminated.

  As described above, in the paper discharge process for each page, it is determined whether or not the sample image output is set. If it is not set, the normal paper discharge process is performed, and if it is set, the printer unit 40 is set. Is a processing configuration in which the sample image output from is output to the sub-tray 64 and the job is resumed.

  The image forming apparatus 1 performs the above-described processing of steps S3 to S5 in units of pages, thereby sequentially forming images with, for example, 1 to 16 image data (page image data) as illustrated in FIG. When a sample image is output every 7 pages in a job to be performed, images are sequentially formed on pages 1 to 6 and then output to the stacker 63 by normal paper discharge, and the seventh page is output to the sub-tray as a sample image output. Then, image formation for the seventh and subsequent pages is performed again and output to the stacker 63 by normal paper discharge.

  Here, as shown in FIG. 8B, when the seventh page is blank paper (which may be a black solid or monotonous page) and is not suitable for sample image output, the image forming apparatus 1 determines that the sample image This is the page after the 7th page that was the output target page, and is suitable for sample image output. If there is no such page, the data size after compression is the largest among pages 1 to 16, and it is suitable for sample image output. A sample image is output on a certain page (eight page which is the next page in the illustrated example).

  As described above, the image forming apparatus 1 selects the sample image data for the sample image from the image data in units of pages of the job, and the printer unit 40 that forms the sample image with the selected sample image data. A compression IC 150 for compressing the image data in units of pages, and determining whether or not the image data size of the selected sample image data after being compressed by the compression unit is greater than or equal to a predetermined value. If the image data size is not greater than or equal to a predetermined value, the selected sample image data is changed to image data for other page units, and the image data of the sample image is formed using the changed image data for other page units as sample image data. It is the structure which has the control part 110 to perform.

  For this reason, when the image forming apparatus 1 forms a sample image on a sheet from image data in page units of a job, the image forming apparatus 1 uses the image data determined based on the compressed data size of the input image data. It is possible to form a sample image suitable for confirmation of image quality.

  Note that the description in the above-described embodiment shows an example, and the present invention is not limited to this. The configuration and operation in the above-described embodiment can be changed as appropriate without departing from the scope of the invention.

1 is a conceptual diagram illustrating the configuration of an image forming apparatus 1. 2 is a block diagram schematically showing a functional configuration of the image forming apparatus 1. FIG. 3 is a flowchart showing an operation of the image forming apparatus 1. 3 is a conceptual diagram illustrating a setting screen of the image forming apparatus 1. FIG. 4 is a flowchart illustrating a paper feed process of the image forming apparatus 1. (A) is a flowchart showing an image forming process of the image forming apparatus 1, and (b) is a flowchart showing a next page image forming process of the image forming apparatus 1. 4 is a flowchart showing a paper discharge process of the image forming apparatus 1. (A) is a conceptual diagram illustrating output of a sample image, and (b) is a conceptual diagram illustrating output of a sample image with image data of the next page.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 100 Control board 110 Control part 120 Non-volatile memory 130 RAM
140 Reading processing unit 150 Compression IC
160 DRAM control IC
170 Image memory 171 Compression memory 172 Page memory 180 Decompression IC
190 Write processing unit 200 Clock IC
10 Printer Controller 11 Controller Control Unit 12 DRAM Control IC
13 Image memory 14 Communication control unit 15 NIC
20 Image Reading Unit 21 ADF Unit 22 Scanner Unit 23 CCD Image Sensor 24 Image Reading Control Unit 30 Operation Display Unit 31 LCD
32 Operation Display Control Unit 40 Printer Unit 41 Conveying Mechanism 42 Image Forming Unit 43 Fixing Unit 44 Printer Control Unit 50 Paper Feed Units 51-54 Paper Feed Tray 60 Post-Processing Unit 61 Post-Processing Control Unit 62 Carrying Unit 63 Stacker 64 Subtray 65 Main Tray 70 HDD
G Sample output setting screen G1 Mode setting area G2 Period setting area G3 Recovery setting area PC User terminal

Claims (3)

In an image forming apparatus having a printer unit that selects sample image data for a sample image from image data in page units of a job, and forms a sample image with the selected sample image data.
A compression unit that compresses the image data in units of pages;
It is determined whether the image data size after compression by the compression unit of the selected sample image data is greater than or equal to a predetermined value, and when the image data size after compression is not greater than or equal to a predetermined value, the selected sample image An image forming apparatus comprising: a control unit that changes data to image data of another page unit, and forms an image of a sample image using the changed image data of another page unit as sample image data.   2. The image forming apparatus according to claim 1, wherein the other page unit image data to be changed is image data of the next page of the page unit image data of the selected job.   2. The other page-unit image data to be changed is image data having an image data size having the largest compressed image data size among the page-unit image data of the job. The image forming apparatus described in 1.

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