Image forming apparatus and image forming system

Abstract

The present invention provides an image forming apparatus and an image forming system. The image forming apparatus includes: a printer configured to print image data on a print medium; a memory; and a controller configured to compare reference image data with an image printed on the print medium, wherein the controller is configured to: perform layout processing of the image data on the print medium based on the size of the print medium and the image size of the image data, calculate offset information during the layout processing of the image data on the print medium, and store the image data subjected to the layout processing and the offset information in the memory.

Description

Technical Field

[0001] The present invention relates to an image forming apparatus and an image forming system. Background Art

[0002] In recent years, a printing system that can inspect a sheet printed by a printing apparatus during conveyance by an inspection apparatus has been known. When inspecting a printed sheet, the inspection apparatus first reads an image of the conveyed printed sheet and registers the read image as a reference image. Then, the inspection apparatus analyzes an image of the output product (printed sheet) of the executed printing job and compares the image with the reference image to determine whether the printed sheet is normal. For example, the inspection apparatus can detect missing lines, missing images, printing stains, missing pages, and color drift in a barcode or grid line by inspection.

[0003] Some inspection systems are configured to print an image to be inspected in advance and register the image read by the inspection apparatus as a reference image in the inspection apparatus. However, since an inspection system having such a configuration reads a printed sheet during the process of registering the reference image, an operator needs to visually inspect whether the printed output sheet or the read image is suitable as the reference image. The larger the number of pages, the greater the amount of inspection operations by the operator. Therefore, the inspection operation may take a long time and operation errors may occur. In view of this, an inspection system is known which is configured to compensate for the amount of adjustment made to raster data during an image processing operation during raster image processor (RIP) image inspection and set the obtained image data as a reference image in the inspection apparatus (Japanese Patent Application Laid-Open No. 2019-95476).

[0004] However, the input image of a printing job does not necessarily have the same size as the sheet size.

[0005] For example, considering the print margins of a printing apparatus, some jobs are configured such that the input image does not include the margin portion. Some printing jobs are configured to print image data on a sheet having a size different from the size of the image data. If the image data of the above printing job is registered as a reference image in the inspection apparatus, since the size of the read image read by the inspection apparatus is the same as the sheet size, the read image does not match the reference image in size during printing. Therefore, the inspection result may be abnormal due to misalignment of the inspection position. Summary of the Invention

[0006] According to one aspect of the present invention, an image forming apparatus includes: a printer configured to print image data on a print medium; a memory; and a controller configured to compare reference image data with an image printed on the print medium, wherein the controller is configured to perform layout processing of the image data on the print medium based on the size of the print medium and the image size of the image data, calculate offset information during the layout processing of the image data on the print medium, and store the image data subjected to the layout processing and the offset information in the memory.

[0007] Other features of the present invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is an overall view of the hardware configuration of an image forming system.

[0009] Figure 2 is a block diagram illustrating the system configuration of the image forming system.

[0010] Figure 3 is a schematic diagram illustrating a mechanical cross-sectional view of the image forming apparatus.

[0011] Figure 4 is a flowchart illustrating a conventional process for registering a reference image.

[0012] Figure 5 is a flowchart illustrating a process for registering a reference image according to an exemplary embodiment.

[0013] Figure 6 is a diagram illustrating the margins of a sheet printed by the image forming apparatus.

[0014] Figure 7A 、 Figure 7B and Figure 7C are diagrams illustrating the relationship between an input image with margins removed and the sheet size.

[0015] Figure 8A 、 Figure 8B and Figure 8C are diagrams illustrating the relationship between an input image and the sheet size when the specified sheet size is different from the input image size.

[0016] Figure 9 is a flowchart illustrating a process for generating layout information and registering a reference image.

[0017] Figure 10A 、 Figure 10B and Figure 10CIt is a diagram showing the orientation difference between the illustrated image data and the sheet and the layout offset amount.

[0018] Figure 11 It is a flowchart showing the processing during the inspection by the inspection device.

[0019] Figure 12A 、 Figure 12B and Figure 12C It is a diagram showing the orientation of the reference image and the inspection position of the inspection image. Detailed Description of the Invention

[0020] Exemplary embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following exemplary embodiments are not intended to limit the present invention, and all combinations of the features described in the exemplary embodiments are not necessarily indispensable for the solution means of the present invention. The external controller according to the exemplary embodiment may be referred to as an image processing controller, a digital front end (DFE), or a print server. The image forming apparatus may be referred to as a multifunction peripheral (MFP).

[0021] Figure 1 It is an overall view of the hardware configuration of an image forming system according to a first exemplary embodiment. The image forming system includes an image forming apparatus 101 and an external controller 102. The image forming apparatus 101 and the external controller 102 are communicably connected via an internal local area network (LAN) 105 and a video cable 106. The external controller 102 is communicably connected to a personal computer (PC) 103 via an external LAN 104. A print instruction is given from the PC 103 to the external controller 102.

[0022] A printer driver having a function of converting print data into a print description language that can be processed by the external controller 102 is installed on the PC 103. A user who performs printing can issue a print instruction from each application via the printer driver. The printer driver transmits the print data to the external controller 102 based on the print instruction from the user. After receiving the print instruction from the PC 103, the external controller 102 performs data analysis and rasterization processing, and submits the print data to the image forming apparatus 101 and gives a print instruction. The external controller 102 submits the print data to the image forming apparatus 101 via the internal LAN 105, and submits the rasterized image data via the video cable 106.

[0023] Next, the image forming apparatus 101 will be described. The image forming apparatus 101 includes a plurality of apparatuses having different functions, and the apparatuses are connected and configured to be able to perform complex print processing such as binding.

[0024] The printing device 107 forms an image on a sheet conveyed from a sheet feeding unit located below the printing device 107 using toner. Although the following description will be given by taking a sheet as an example, any printing medium other than paper can also be used.

[0025] The configuration and operation principle of the printing device 107 will be described below. A light beam (such as a laser) modulated based on image data and reflected by a rotating polygon mirror is used as scanning light to irradiate a photosensitive drum.

[0026] The electrostatic latent image formed on the photosensitive drum by the laser is developed using toner, and the developed toner image is transferred onto the sheet via a transfer belt. Such a series of image forming processes are sequentially performed using yellow (Y), magenta (M), cyan (C), and black (K) toners to form a full-color image on the sheet. The sheet with the full-color image formed thereon is conveyed to a fixing device. The fixing device includes a roller and a belt. The roller includes a built-in heat source such as a halogen heater, and melts and fixes the toner on the sheet onto which the toner image is transferred by heat and pressure. The inserter 108 is a device for inserting an inserted sheet. The inserter 108 can insert the inserted sheet into the sheet group printed and conveyed by the printing device 107 at a given position.

[0027] The inspection device 109 is a device for determining whether a printed image is normal by reading the image on the conveyed sheet (printed product) and comparing the generated image data with pre-registered reference image data. After the determination, for example, the printed products determined to be normal and the printed products determined to be defective are separately discharged.

[0028] The high-capacity stacker 110 is a device capable of stacking a large number of sheets. The finisher 111 is a device for performing finishing processing on the conveyed sheets. The finisher 111 can perform finishing processes such as binding, punching, saddle stitching, etc. according to settings, and discharges the resulting product to a discharge tray.

[0029] Refer to Figure 1 The described image forming system is configured such that the external controller 102 is connected to the image forming device 101. However, the present invention is not limited to the configuration connected to the external controller 102.

[0030] More specifically, the image forming device 101 can be connected to an external LAN 104, and the PC 103 can transmit print data that can be processed by the image forming device 101. In this configuration, the image forming device 101 performs data analysis and rasterization processing, and executes printing processing.

[0031] Figure 2 is a block diagram illustrating the system configuration of the image forming device 101, the external controller 102, and the PC 103.

[0032] First, the configuration of the printing device 107 of the image forming apparatus 101 will be described. The printing device 107 of the image forming apparatus 101 includes a communication interface (I / F) 217, a LAN I / F 218, a video I / F 220, a hard disk driver (HDD) 221, a central processing unit (CPU) 222, a memory 223, an operation unit 224, and a display 225. The printing device 107 of the image forming apparatus 101 further includes an original exposure unit 226, a laser exposure unit 227, an image forming unit 228, a fixing unit 229, and a sheet feeding unit 230. These components are connected via a system bus 231.

[0033] The communication I / F 217 is connected to the inserter 108, the inspection device 109, the large-capacity stacker 110, and the finisher 111 via a communication cable 254, and performs communication for controlling these devices.

[0034] The LAN I / F 218 is connected to the external controller 102 via the internal LAN 105 and transmits print data.

[0035] The video I / F 220 is connected to the external controller 102 via a video cable 106 and transmits rasterized image data.

[0036] The HDD 221 is a storage device that stores programs and data. The CPU 222 comprehensively controls image processing and printing based on programs and the like stored in the HDD 221. The memory 223 stores programs used by the CPU 222 when performing various types of processing, as well as image data, and serves as a work area.

[0037] The operation unit 224 accepts various setting inputs and operation instructions from the user. The display 225 displays setting information about the image forming apparatus 101 and the processing status of print jobs.

[0038] The original exposure unit 226 performs processing for reading an original using the copying function or the scanning function. The original exposure unit 226 reads original data by illuminating a sheet placed by the user with an exposure lamp and capturing an image using a charge-coupled device (CCD) camera.

[0039] The laser exposure unit 227 is a device for performing primary charging and laser exposure to irradiate a photosensitive drum with a laser to form an electrostatic latent image. First, the laser exposure unit 227 performs primary charging to charge the surface of the photosensitive drum to a uniform negative potential. Next, the laser exposure unit 227 uses a laser driver to irradiate the photosensitive drum with a laser while adjusting the reflection angle using a polygon mirror. The negative charges in the irradiated part are thereby neutralized to form an electrostatic latent image. The image forming unit 228 is a device for transferring toner onto a sheet. The image forming unit 228 includes a developing unit, a transfer unit, and a toner replenishing unit, and transfers the toner on the photosensitive drum onto the sheet via a transfer belt.

[0040] In the developing unit, a developing cylinder causes negatively charged toner to adhere to the electrostatic latent image on the surface of the photosensitive drum, thereby visualizing the electrostatic latent image. The transfer unit performs primary transfer and secondary transfer. In primary transfer, a positive potential is applied to a primary transfer roller, and the toner on the surface of the photosensitive drum is transferred to the transfer belt. In secondary transfer, a positive potential is applied to a secondary transfer outer roller to transfer the toner on the transfer belt onto the sheet. The fixing unit 229 is a device for melting the toner on the sheet and fixing the toner to the sheet by heat and pressure. The fixing unit 229 includes a heating roller and a pressure roller. The sheet feeding unit 230 is a device for feeding a sheet. The sheet feeding operation and the conveying operation are controlled by using rollers and various sensors.

[0041] Next, the configuration of the inserter 108 of the image forming apparatus 101 will be described. The inserter 108 of the image forming apparatus 101 includes a communication I / F 232, a CPU 233, a memory 234, and a feed control unit 235. These components are connected via a system bus 236. The communication I / F 232 is connected to the printing apparatus 107 via a communication cable 254 and performs control communication. The CPU 233 performs various controls for feeding a sheet based on a control program stored in the memory 234. The memory 234 is a storage device that stores the control program. The feed control unit 235 controls the rollers and sensors while controlling the feeding and conveying of the sheet from the sheet feeding unit of the inserter 108 and the sheet conveyed from the printing apparatus 107 based on an instruction from the CPU 222.

[0042] Then, the configuration of the inspection device 109 of the image forming apparatus 101 will be described. The inspection device 109 of the image forming apparatus 101 includes a communication I / F 237, a CPU 238, a memory 239, an imaging unit 240, a display unit 241, an operation unit 242, and an HDD 272. These components are connected via a system bus 243. The communication I / F 237 is connected to the printing apparatus 107 via a communication cable 254 and performs control communication.

[0043] The communication cable 254 and the communication I / F 237 are also used to receive a reference image to be used for inspection from the printing device 107. The received reference image is stored in the HDD 272. The CPU 238 performs various types of control for inspection based on the control program stored in the memory 239. The memory 239 is a storage device that stores the control program.

[0044] The imaging unit 240 captures an image of the conveyed sheet based on an instruction from the CPU 238. The CPU 238 compares the image captured by the imaging unit 240 with the reference image stored in the HDD 272 and determines whether the printed image is normal. The display unit 241 displays the inspection result and the setting screen. The operation unit 242 is operated by the user and accepts instructions to change the settings of the inspection device 109 and register the reference image. The HDD 272 stores the reference image.

[0045] If the inspection device 109 does not include the HDD 272, the reference image can be stored in the HDD 221. The inspection device 109 can be configured to read the reference image from the HDD 221 into the memory 239 and use the reference image in the process of determining whether the printed image is normal.

[0046] Next, the configuration of the large-capacity stacker 110 of the image forming apparatus 101 will be described. The large-capacity stacker 110 of the image forming apparatus 101 includes a communication I / F 244, a CPU 245, a memory 246, and a discharge control unit 247. These components are connected via a system bus 248. The communication I / F 244 is connected to the printing device 107 via a communication cable 254 and performs control communication. The CPU 245 performs various types of control for sheet discharge based on the control program stored in the memory 246. The memory 246 is a storage device that stores the control program. The discharge control unit 247 controls the conveyance of the sheet to the stacking tray, the escape tray, and the finisher 111 in the subsequent stage based on an instruction from the CPU 245.

[0047] Next, the configuration of the sorter 111 of the image forming apparatus 101 will be described. The sorter 111 of the image forming apparatus 101 includes a communication I / F 249, a CPU 250, a memory 251, a discharge control unit 252, and a sorting processing unit 253. These components are connected via a system bus 255. The communication I / F 249 is connected to the printing apparatus 107 via a communication cable 254 and performs control communication. The CPU 250 performs various types of control for sorting and sheet discharging based on a control program stored in the memory 251. The memory 251 is a storage device that stores the control program. The discharge control unit 252 controls the conveyance and discharge of sheets based on an instruction from the CPU 250. The sorting processing unit 253 controls sorting processes such as binding, punching, and saddle stitching based on an instruction from the CPU 250.

[0048] Next, the configuration of the external controller 102 will be described. The external controller 102 includes a CPU 208, a memory 209, an HDD 210, a keyboard 211, a display 212, a LAN I / F 213, a LAN I / F 214, and a video I / F 215 that are connected via a system bus 216. The CPU 208 comprehensively performs processes such as receiving print data from the PC 103, raster image processor (RIP) processing, and transmitting the print data to the image forming apparatus 101 based on programs and data stored in the HDD 210.

[0049] The memory 209 stores programs and data used by the CPU 208 during various types of processing and serves as a work area. The HDD 210 stores programs and data to be used for print processing and other operations. The keyboard 211 is a device for inputting operation instructions for the external controller 102. The display 212 displays information about applications running on the external controller 102 using still or moving image video signals. The LAN I / F 213 is connected to the PC 103 via an external LAN 104 and transmits print instructions. The LAN I / F 214 is connected to the image forming apparatus 101 via an internal LAN 105 and transmits print data as a print instruction. The video I / F 215 is connected to the image forming apparatus 101 via a video cable 106 and transmits rasterized image data.

[0050] Next, the configuration of the PC 103 will be described. The PC 103 includes a CPU 201, a memory 202, an HDD 203, a keyboard 204, a display 205, and a LAN I / F 206 that are connected via a system bus 207. The CPU 201 generates print data and executes print instructions based on a document processing program stored in the HDD 203.

[0051] The CPU 201 also comprehensively controls the devices connected to the system bus 207. The memory 202 stores the programs and data used by the CPU 201 during various types of processing and serves as a workspace. The HDD 203 stores the programs and data to be used for print processing and other operations. The keyboard 204 is a device for inputting operation instructions for the PC 103. The display 205 uses still or moving image video signals to display information about the applications running on the PC 103. The LAN I / F 206 is connected to the external LAN 104 and transmits print instructions.

[0052] In the foregoing description, the external controller 102 and the image forming apparatus 101 are connected via the internal LAN 105 and the video cable 106. However, the external controller 102 and the image forming apparatus 101 may be configured to be connected only via the video cable 106, as long as data for printing can be transmitted and received. Each of the memories 202, 209, 223, 234, 239, 246, and 251 may be any storage device for storing data and programs. For example, each of the memories 202, 209, 223, 234, 239, 246, and 251 may be replaced with a volatile random access memory (RAM), a non-volatile ROM, a built-in HDD, an external HDD, or a universal serial bus (USB) memory.

[0053] Figure 3 is a mechanical cross-sectional view of the image forming apparatus 101. The printing device 107 prints the formed image on a sheet. The sheet feed tables 301 and 302 can store various types of sheets. Information (sheet size and sheet type) about the sheets stored in each of the sheet feed tables 301 and 302 can be set from the operation unit 224 of the printing device 107.

[0054] Each of the sheet feed tables 301 and 302 can separate only the topmost sheet stored in the sheets and convey the sheet to the sheet conveyance path 303. The developing stations 304, 305, 306, and 307 form images using Y, M, C, and K color toners, respectively, to form a color image. The toner image formed here is transferred to the transfer belt 308 at one time. The transfer belt 308 rotates clockwise in the figure, and the toner image is transferred to the sheet conveyed from the sheet conveyance path 303 at the secondary transfer position 309.

[0055] The display 225 displays the printing status of the image forming apparatus 101 and information for setting. The fixing unit 311 fixes the toner image onto the sheet. The fixing unit 311 includes a pressure roller and a heating roller, and melts and pressurizes the toner by passing the sheet between the rollers to fix the toner image onto the sheet. The sheet passing through the fixing unit 311 is conveyed to the sheet conveyance path 315 through the sheet conveyance path 312.

[0056] Depending on the sheet type, additional melting and pressurization may be required for fixing. In this case, the sheet passing through the fixing unit 311 is conveyed to the second fixing unit 313 through the upper sheet conveyance path. The second fixing unit 313 applies additional melting and pressurization, and then the sheet is conveyed to the sheet conveyance path 315 through the sheet conveyance path 314. If the image forming mode is the duplex mode, the sheet is conveyed to the sheet inversion path 316. The sheet is inverted using the sheet inversion path 316, conveyed to the duplex conveyance path 317, and the sheet undergoes image transfer on the second side at the secondary transfer position 309.

[0057] The inserter 108 inserts an inserted sheet. The inserter 108 includes an inserter tray 321, and merges the inserted sheet fed to the inserter tray 321 into the conveyance path. Thus, the inserted sheet can be inserted into a series of sheets conveyed from the printing apparatus 107 at a given position and conveyed to a subsequent apparatus.

[0058] The sheet passing through the inserter 108 is conveyed to the inspection device 109. The inspection device 109 includes cameras 331 and 332 facing each other. The camera 331 is intended to read the front side of the sheet, while the camera 332 is intended to read the back side of the sheet. The inspection device 109 can use the cameras 331, 332 to read the image of the sheet conveyed to the sheet conveyance path 333 when the sheet reaches a predetermined position, and determine whether the image printed by the printing apparatus 107 is normal. The display unit 241 displays the result of the inspection performed by the inspection device 109.

[0059] The high-capacity stacker 110 is a high-capacity stacker on which a large number of sheets can be stacked.

[0060] The high-capacity stacker 110 includes a stacking tray 341, and the stacking tray 341 serves as a tray for stacking sheets determined to be normal sheets (printed products) by the inspection device 109. The sheet passing through the inspection device 109 enters the high-capacity stacker 110 through the sheet conveyance path 344. If the sheet is a normal sheet, the sheet from the sheet conveyance path 344 passes through the sheet conveyance path 345 and is stacked on the stacking tray 341.

[0061] The high-capacity stacker 110 further includes a discharge tray 346 that serves as an ejection tray. The discharge tray 346 is an ejection tray for ejecting sheets determined to be defective sheets (printed products) by the inspection device 109. When outputting a sheet to the discharge tray 346, the sheet is conveyed from the sheet conveyance path 344 to the discharge tray 346 via the sheet conveyance path 347. In the process of conveying the sheet to a post-processing device (collator 111) in a subsequent stage of the high-capacity stacker 110, the sheet is conveyed through the sheet conveyance path 348. The reversing unit 349 reverses the sheet. The reversing unit 349 is used to stack the sheets on the stacking tray 341.

[0062] If a sheet is to be stacked on the stacking tray 341, the reversing unit 349 is used to reverse the sheet once so that the sheet is output in the same orientation as when input. If a sheet is to be conveyed to the discharge tray 346 or to a subsequent post-processing device, since the sheet is only ejected without being flipped during stacking, the reversing operation using the reversing unit 349 is not performed.

[0063] The collator 111 is a device for performing a collating process on the conveyed sheets based on a user-specified function. Specifically, the collator 111 has collating functions such as binding (single binding and double binding), punching (double-hole punching and triple-hole punching), and saddle stitching. The collator 111 includes a discharge tray 351 and a discharge tray 352. Sheets are output to the discharge tray 351 through the sheet conveyance path 353. The sheet conveyance path 353 is not available for the collating process.

[0064] Sheets are conveyed to the processing unit 355 via the sheet conveyance path 354 to perform a collating process such as binding. In the processing unit 355, the user-specified collating function is performed on the sheets, and the resulting sheets are output to the discharge tray 352. Each of the discharge trays 351 and 352 can be raised and lowered. The discharge tray 351 can be lowered so that sheets that have undergone the collating process in the processing unit 355 can be stacked thereon. If saddle stitching is specified, the saddle stitching processing unit 356 performs saddle stitching on the sheets, folds the sheets in half, and outputs the sheets to the saddle stitching tray 358 via the sheet conveyance path 357. The saddle stitching tray 358 has a conveyor configuration for conveying the saddle-stitched bundles stacked on the saddle stitching tray 358 to the left.

[0065] Figure 4 It is a flowchart illustrating a conventional process for registering a reference image.

[0066] Use Figure 2The system configuration shown checks the printed product printed by the image forming apparatus 101. For the check, a reference image is registered in advance in the HDD 272 of the inspection apparatus 109. During printing, the images on the sheet are read using cameras 331 and 332, and the images are compared with the reference image to determine whether the images on the sheet are normal. So far, the reference image has been registered by actually performing printing, reading the images on the sheet using cameras 331 and 332, and registering the read images in the HDD 272 as the reference image.

[0067] In step S401, the operation unit 242 accepts the operator mode setting of the inspection apparatus 109. Thereby, the inspection apparatus 109 is set to the reference image registration mode. In the normal registration mode, since the images on the sheet read by cameras 331 and 332 are registered as the reference image, the inspection apparatus 109 enters the standby state to wait for the sheet to be conveyed to the sheet conveyance path 333.

[0068] In step S402, the external controller 102 accepts a print instruction from the PC 103. The print instruction accepted here is a print job that the operator wants to check.

[0069] In step S403, the printing apparatus 107 executes the print job and prints the image data on the sheet. The inspection apparatus 109 reads the printed sheet using cameras 331 and 332, and stores the read images in the HDD 272. The operator visually observes the output printed sheet or the preview image displayed on the display unit 241, and determines whether the read images are suitable as the reference image.

[0070] In step S404, if the registration of the reference image is accepted (Yes in step S404), the process ends. On the other hand, if the registration of the reference image is not accepted (No in step S404), the process returns to step S401. Here, the operator cleans the image forming apparatus 101 and changes the settings of the print job, so that the read images can be registered as the reference image. Steps S401 to S404 are repeated until the inspection apparatus 109 accepts the registration of the reference image.

[0071] Since the normal registration of the reference image includes actually printing the print job and inputting the reference image by the same input method as the inspection image, it is not necessary to consider the image size and orientation, and the inspection can be performed by simple image comparison. However, if the print job includes a large number of pages, since the operator visually determines whether all pages are suitable as the reference image, there are problems of possible inspection errors and long inspection time.

[0072] Figure 5 is a flowchart illustrating the process for registering a reference image according to the present exemplary embodiment.

[0073] In the present exemplary embodiment, instead of reading a print sheet, the reference image is registered by registering image data generated based on rasterized image data (raster data). In the present exemplary embodiment, the rasterized image data is described as being received from the external controller 102 via the video cable 106. However, this is not restrictive. For example, the image forming apparatus 101 may receive a print job (e.g., including page description language (PDL) data) from the PC 103 and rasterize the image data. Figure 4

[0074] In step S501, the operator makes a setting from the operation unit 242 to set the inspection device 109 to the reference image registration mode. Different from the conventional registration mode, the printing device 107 waits for the input of the rasterized image data from the external controller 102 via the video cable 106.

[0075] In step S502, the external controller 102 receives a print instruction from the PC 103. The print instruction includes print settings, which at least include the size of the sheet to be printed, the resolution, the image orientation, the image size per page, and the image data. The print instruction received here is a print job that the operator wants to inspect. In the present exemplary embodiment, the print instruction is received to provide operability consistent with the conventional process for registering the reference image. However, an instruction to register the print job as a reference image registration job may be received from the PC 103.

[0076] In step S503, the printing device 107 determines the layout of the image data input from the external controller 102 via the video cable 106 to be printed on the sheet, and determines the rotation angle of the image and the offset from the sheet edge based on the layout.

[0077] Then, the printing device 107 transmits the image data as the reference image to the inspection device 109 via the communication cable 254, and transmits the calculated rotation angle of the image and the offset information regarding the offset from the sheet edge as layout information. The details of the process of step S503 are as Figure 9 shown. The inspection device 109 registers the image data as the reference image in the memory 239 together with the layout information.

[0078] ​In step S504, if the registration of the reference image is accepted (Yes in step S504), the process ends, and the reference image stored in the HDD 272 in step S503 is retained. On the other hand, if the registration of the reference image is not accepted (No in step S504), the process returns to S501, and the reference image stored in the HDD 272 is deleted. Here, the operator changes the settings of the print job so that the input image data can be registered as the reference image. Steps S501 to S504 are repeated until the inspection device 109 accepts the registration of the reference image.

[0079] Although the reference image is stored in the HDD 272 in step S503, alternatively, the reference image can be stored in the memory 239. In this case, if the registration of the reference image is accepted in step S504, the reference image stored in the memory 239 is stored in the HDD 272. If the registration of the reference image is not accepted in step S504, the reference image stored in the memory 239 is not stored in the HDD 272.

[0080] Then, the reference Figures 6 to 10C will describe the details of the process for generating and transferring the reference image in step S503. First, the reference Figure 6 will describe the relationship between the image data to be printed on the sheet and the margins.

[0081] Figure 6 FIG. is a diagram showing the margins of the sheet for the image forming apparatus 101 to print. The sheet 601 is the sheet on which the image data is to be printed and is conveyed in the direction of the arrow. The area within the dashed line 602 is the area where the image forming apparatus 101 actually prints the image, and the area outside the dashed line 602 is the area where no image is printed. Therefore, if image data of the same size as the sheet size of the sheet 601 is received from the external controller 102, the image in that area cannot be printed in the area outside the dashed line 602.

[0082] In the present exemplary embodiment, all the top, bottom, left, and right margins have the same width. However, if the printable areas at the leading and trailing edges or the distal and proximal sides in the conveyance direction are different depending on the configuration of the image forming apparatus 101, the top, bottom, left, and right margins may have different widths.

[0083] Figure 7A 、 Figure 7B and Figure 7CFIG. is a diagram showing the relationship between the input image with the page margins removed and the sheet size. The image forming apparatus 101 receives rasterized image data from the external controller 102 via the video cable 106. In an image forming apparatus used in a printing system configured to connect to an external controller, it is usually a high-speed machine, and the input speed of the image data can affect the throughput of the printing system. Therefore, in order to minimize the data size of the image data as much as possible, there is an external controller 102 which is configured to remove the edge image that is not desired to be printed by the image forming apparatus 101 and transmit the resulting image data to the image forming apparatus 101. More specifically, such an external controller 102 transmits only the image within the dotted line 602 of Figure 6 as image data to the image forming apparatus 101.

[0084] Figure 7A FIG. illustrates an example of the image data of the image with the page margins removed. Figure 7B FIG. illustrates the sheet size 702 of the A4 sheet size which is the actual sheet to be printed. The image 701 of the image data received from the external controller 102 falls within Figure 6 the dotted line 602 of, that is, smaller than the A4 sheet size. The CPU 222 reserves a memory as large as the A4 sheet size in the memory 223, and generates an image of the A4 sheet size by laying out the image data corresponding to the image 701 at the center. The image forming apparatus 101 prints the laid-out A4-size image to produce Figure 7C the print output shown. The printed product 703 is an A4 sheet, and the image data on the image 701 is centered and printed in the area 704. In the present exemplary embodiment, since the top, bottom, left, and right page margins have the same width, the image 701 is printed centered. However, if the page margins are not uniform, the image 701 may be printed off-center based on the page margins.

[0085] Figure 8A 、 Figure 8B and Figure 8C FIGS. are diagrams showing the relationship between the input image and the sheet size when the specified sheet size is different from the input image size. Similar to Figure 7A 、 Figure 7B and Figure 7C , Figure 8A shows the image data received from the external controller 102, Figure 8B shows the size of the sheet to be printed, while Figure 8C shows the print output.

[0086] In Figure 8A 、 Figure 8B and Figure 8C ,no edge image data is removed from the image data received from the external controller 102.

[0087] Figure 8A , Figure 8B and Figure 8C illustrate examples of image data having a print aspect ratio different from the aspect ratio of the sheet size used for print output. A print job can specify the sheet to be printed for each image, and can specify a sheet size different from the image size. The sheet size 802 is the A3 sheet size, and an image 801 having a print aspect ratio different from the aspect ratio of the A3 sheet size is printed on the sheet.

[0088] The CPU 222 reserves a memory as large as the A3 sheet size in the memory 223, and generates an image of the A3 sheet size by laying out the image data corresponding to the image 801 at the center. Since the image forming apparatus 101 can only feed the A3 sheet from the short side first, the orientation of the sheet during printing is the orientation of the printed product 803, that is, the sheet is fed from the short side first along the arrow direction.

[0089] Therefore, the CPU 222 rotates the laid-out A3-size image data by -90° and prints the rotated image data. As Figure 8C shown, the resulting print output is a landscape A3 sheet, and the rotated image data of the image 801 is printed at the center on the landscape A3 sheet as shown in the image 804. It should be understood that the image 804 can be laid out near one side instead of the center.

[0090] Figure 9 is a flowchart illustrating the process for generating layout information and registering a reference image. The program of the printing apparatus 107 related to the flowchart is stored in the HDD 221, loaded into the memory 223, and executed by the CPU 222.

[0091] In step S901, the printing apparatus 107 reads the page data regarding the print job. The page data includes the image data and information related to the image size of the page, the sheet size of the sheet to be printed, the resolution, and the image orientation.

[0092] In step S902, the printing apparatus 107 compares the long side of the image size in the page data read in step S901 with the long side of the sheet size and the short side of the image size with the short side of the sheet size, and determines whether the image size is the same as the sheet size.

[0093] If the image size is the same as the sheet size (Yes in step S902), the process proceeds to step S905. If the image size is different from the sheet size (No in step S902), the process proceeds to step S903. In step S903, the printing apparatus 107 determines whether to rotate the image to fit the sheet based on whether the image data is portrait or landscape with respect to the portrait sheet. For a portrait sheet, if the image data is landscape, the printing apparatus 107 determines to rotate the image.

[0094] Specific examples will be described below with reference to Figure 10A 、 Figure 10B and Figure 10C Description of specific examples. Figure 10A FIG. illustrates the image data, while Figure 10B FIG. illustrates the sheet size. In the example shown, the landscape image 1001 and the portrait sheet 1002 differ in orientation by 90°. In Figure 10A and Figure 10B In the case of, the landscape image 1001 is rotated by 90° to fit the portrait sheet 1002. In step S903, if the printing apparatus 107 determines to rotate the image (Yes in step S903), the process proceeds to step S904. If the printing apparatus 107 determines not to rotate the image (No in step S903), the process proceeds to step S905.

[0095] In step S904, the printing apparatus 107 determines the rotation angle of the image with respect to the sheet. In step S905, the printing apparatus 107 determines the image orientation for actually printing the image data. The sheet size refers to the sheet size of the portrait sheet. For example, if as Figure 8A 、 Figure 8B and Figure 8C shown, an A3 sheet is used, since the A3 sheet can only be fed from the short side first, the printing apparatus 107 determines to rotate the image.

[0096] If finishing such as binding or punching is desired, since the finishing can only be performed in a certain direction due to the mechanical configuration, the orientation of the image to be printed matches the orientation of the sheet for finishing. The printing apparatus 107 finally determines the orientation of the image to be printed on the sheet taking into account the finishing, and also determines the final rotation angle of the image data taking into account the rotation angle determined in step S903.

[0097] In step S906, when laying out the image on the sheet, the printing apparatus 107 calculates the position where the image is to be positioned and printed on the sheet. In the present exemplary embodiment, as described with reference to Figure 7A 、 Figure 7B 、 Figure 7C 、 Figure 8A 、 Figure 8B and Figure 8CAs described, the image data is laid out in the center of the sheet. It should be understood that the image data can be laid out on one side of the sheet close to the edge rather than in the center. Specific examples will be described below with reference to Figure 10C In Figure 10C Since the orientation of image 1001 is different from that of sheet 1002, image 1001 is rotated relative to sheet 1002, and since the sheet size is different from the image size, image 1004 is laid out in the center of sheet 1003.

[0098] If the deviation between the sheet and the image is transmitted to the inspection device 109 together with the image data in advance, the inspection device 109 can determine at which position on the sheet scanned during the inspection for comparison. Since the deviation is only intended to uniquely determine the positional relationship between the sheet and the image, the offset from the edge of the sheet can be derived as the deviation. For example, the offset (position information) 1007 in the X direction from the left edge of the sheet to the image and the offset (position information) 1008 in the Y direction from the upper edge of the sheet to the image are derived as the deviation.

[0099] In the present exemplary embodiment, the image is laid out in the center of the sheet. Therefore, the offset in each of the X direction and the Y direction is derived by (sheet size - image size) / 2. Hereinafter, the final rotation angle determined in step S905, the offset (position information) from the edge of the sheet to the image determined in step S906, and the print surface setting regarding on which surface of the sheet the image is printed are collectively referred to as layout information.

[0100] In step S907, the printing device 107 transmits, via the communication cable 254, the image data (image data laid out on the sheet) subjected to the layout process and the layout information (at least the offset information) to the inspection device 109. The inspection device 109 registers the image data subjected to the layout process as a reference image in the memory 239 and stores the layout information (at least the offset information) as associated information.

[0101] In step S908, the printing device 107 determines whether the page processed in steps S901 to S907 is the last page. If the page is not the last page (in step S908, "no"), the process proceeds to step S901. If the page is the last page (in step S908, "yes"), the process ends.

[0102] Figure 11 is a flowchart showing the processing procedure during the inspection by the inspection device 109. The program of the inspection device 109 related to the flowchart is executed by the CPU 238.

[0103] If a print job to be inspected is started, in step S1101, the inspection device 109 initializes the variables to be used in the flowchart. The process proceeds to step S1102.

[0104] The variables to be initialized include the number of copies N, the number of pages P, and the number of sides D. The inspection device 109 initializes each variable to 1. In step S1102, the inspection device 109 waits for a print sheet to be conveyed to the sheet conveyance path 333. If a sensor 334 upstream of the sheet conveyance path 333 detects a sheet (Yes in step S1102), the process proceeds to step S1103. In step S1103, the inspection device 109 scans the sheet using cameras 331 and 332 after a predetermined time has elapsed since the sheet was detected by the sensor 334. Thus, the sheet is scanned from the leading edge in the conveyance direction, and an inspection image is generated. In the present exemplary embodiment, regardless of whether the print sheet is single-sided or double-sided, both sides of the sheet are scanned using cameras 331 and 332.

[0105] In step S1104, the inspection device 109 reads the rotation angle (final rotation angle) and the reference image from the layout information stored in the memory 239. If the rotation angle is not 0° (No in step S1104), the process proceeds to step S1105 for image rotation. If the rotation angle is 0° (Yes in step S1104), the process proceeds to step S1106. In step S1105, the inspection device 109 rotates the reference image by an angle as large as the rotation angle.

[0106] For example, Figure 12A The reference image 1201 is illustrated. Figure 12B The rotated reference image 1202 is illustrated, where the rotation angle is -90°.

[0107] In step S1106, the inspection device 109 reads the offsets from the sheet edge included in the layout information stored in the memory 239 and determines whether the offsets in both the X and Y directions are 0. If both offsets are 0 (Yes in step S1106), since there is no need to adjust the inspection position of the image, the process proceeds to step S1108. If any one of the offsets in the X direction and the Y direction is not 0 (No in step S1106), the process proceeds to step S1107.

[0108] In step S1107, as Figure 12CAs shown, since the inspection image scanned in step S1103 has a different size from the reference image, the inspection device 109 inspects the inspection image by shifting the reference image relative to the inspection image by an amount equal to the offset. In step S1108, since the inspection image and the reference image have the same image size, the inspection device 109 performs a normal inspection. In step S1109, the inspection device 109 increments the page number P and the number of sides D by one respectively.

[0109] In step S1110, the inspection device 109 notifies the printing device 107 of the inspection result. The process proceeds to step S1118. In step S1118, if the inspection result is normal ("Yes" in step S1118), the process proceeds to step S1111. If the inspection result is abnormal ("No" in step S1118), the process proceeds to step S1119. In step S1119, the printing device 107 processes based on the inspection result. Examples of such processing include instructing the high-capacity stacker 110 to discharge the sheets to the discharge tray 346 (the tray on which the printed products with abnormal inspection results are stacked) and pausing the printing. After step S1119, the process proceeds to step S1120.

[0110] In step S1120, the inspection device 109 determines whether the image formation mode is the double-sided mode. If the image formation mode is not the double-sided mode ("No" in step S1120), the process proceeds to step S1114. If the image formation mode is the double-sided mode ("Yes" in step S1120), the process proceeds to step S1121. In step S1121, the inspection device 109 determines whether the double sides have been inspected based on the number of sides D. In step S1121, if the inspection device 109 determines that the double sides have been inspected (D > 2) ("Yes" in step S1121), the process proceeds to step S1114. If the double sides have not been inspected (D ≤ 2) ("No" in step S1121), the process proceeds to step S1122. In step S1122, the inspection device 109 increments the page number P by one. The process proceeds to step S1114.

[0111] In step S1111, the inspection device 109 determines whether both sides of the inspection sheet are printed. If both sides are printed ("Yes" in step S1111), the process proceeds to step S1112. If only one side of the inspection sheet is printed ("No" in step S1111), the process proceeds to step S1113. In step S1112, the inspection device 109 determines whether both sides have been inspected based on the number of sides D. If the inspection of both sides has been completed (D>2) ("Yes" in step S1112), the process proceeds to step S1123. If the inspection of both sides has not been completed (D≤2) ("No" in step S1112), the process proceeds to step S1104 to inspect the other side.

[0112] In step S1113 , since only one side of the sheet is printed, the inspection device 109 deletes the inspection image of the unprinted side.

[0113] In step S1123 , the checking device 109 discharges the sheet whose inspection result is normal to the tray (the tray on which the printed products with normal inspection results are stacked). In step S1114 , the checking device 109 initializes the number of sides D to 1.

[0114] In step S1115, the checking device 109 checks the number of pages P to determine whether the checking up to the last page has been completed. If the checking up to the last page has been completed ("Yes" in step S1115), the process proceeds to step S1116. If the checking up to the last page has not been completed ("No" in step S1115), the process proceeds to step S1102.

[0115] In step S1116, the checking device 109 initializes the number of pages P to 1, and since one copy has been printed, the number of copies N is increased. In step S1117, the checking device 109 checks the number of copies N to determine whether the designated number of copies has been checked. If the designated number of copies has not been checked ("No" in step S1117), the process proceeds to step S1102. If the designated number of copies has been checked ("Yes" in step S1117), the process ends.

[0116] Figure 12A , Figure 12B and Figure 12C is a diagram illustrating the rotation of a reference image and the inspection position of an inspection image.

[0117] Figure 12A There is illustrated an example of the reference image registered in the memory 239. For example, it is assumed that the reference image 1201 is a portrait A3 image. Figure 12B The image is illustrated as a reference image 1201 after being rotated by -90°. For example, the rotated reference image 1202 is used for inspection.

[0118] Figure 12C An inspection image is illustrated. Since the reference image 1202 is only as large as the dashed box 1204 in the inspection image 1203, the inspection image 1203 is inspected by comparing it with the reference image by offsetting from the upper left corner of the inspection image 1203 along the arrow 1205 shown. This enables inspection at the appropriate position.

[0119] According to the configuration of this exemplary embodiment, if the image size of a print job is different from the sheet size, layout information including the rotation angle of the image and the offset from the sheet edge can be registered in the inspection device 109 together with the reference image, taking into account the layout on the sheet during printing. In addition, appropriate inspection can be performed by adjusting the rotation and comparison position of the reference image during inspection. In this exemplary embodiment, the image size is described as smaller than the sheet size. However, it should be understood that if the image size is larger than the sheet size, appropriate inspection can be performed by generating the reference image with the same layout as during printing.

[0120] Other embodiments

[0121] Embodiments of the present invention can also be implemented by the following method, that is, software (program) that executes the functions of the above embodiments is provided to a system or device via a network or various storage media, and the computer or central processing unit (CPU), microprocessing unit (MPU) of the system or device reads and executes the program.

[0122] Although the present invention includes multiple embodiments, it should be understood that the present invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims should be given the broadest interpretation to cover all such variations and equivalent structures and functions.

Claims

1. An image forming apparatus, the image forming apparatus comprising: A printer configured to print image data on a print medium; A memory; And A controller configured to compare reference image data with an image printed on the print medium, wherein the controller is configured to Perform layout processing of the image data on the print medium based on the size of the print medium and the image size of the image data, In the layout processing of the image data on the print medium, calculate offset information, where the offset information is position information about the position of the image data from the edge of the print medium, and Store the image data after the layout processing and the offset information in the memory, wherein, when the controller compares the reference image data with the image printed on the print medium, in the case where the offset information is not 0, the controller uses the offset information to determine the position of the reference image corresponding to the position of the scanned image, and the scanned image is obtained by scanning the image printed on the print medium.

2. The image forming apparatus according to claim 1, wherein, The offset information includes position information about the position of the image data from the edge of the print medium along the X direction and position information about the position of the image data from the edge of the print medium along the Y direction.

3. The image forming apparatus according to claim 1, wherein, The layout processing includes laying out the image data in the center of the print medium.

4. The image forming apparatus according to claim 1, wherein, The layout processing includes comparing the size of the print medium with the image size of the image data, and rotating the image data in the case where the size of the print medium is different from the image size.

5. The image forming apparatus according to claim 1, wherein, The memory is configured to store the offset information page by page in the case where the printer prints multi-page image data on the print medium.

6. The image forming apparatus according to any one of claims 1 to 5, the image forming apparatus further comprising a scanner configured to read a sheet and generate image data, wherein, The controller is configured to compare the image data after the layout processing stored in the memory with the image data generated by the scanner based on the offset information.

7. The image forming apparatus according to claim 6, wherein, The controller is configured to compare the entire image data after the layout processing with the entire generated image data in the case where the offset information is zero.

8. The image forming apparatus according to claim 6, wherein, The controller is configured to compare a part of the image data after the layout processing within the range based on the offset information with a part of the generated image data within the range based on the offset information in the case where the offset information is not zero.

9. An image forming system, the image forming system comprising: A printing device configured to print image data on a print medium; And A control device configured to compare reference image data with an image printed on the print medium, wherein the image forming system is configured to Perform layout processing of the image data on the print medium based on the size of the print medium and the image size of the image data, In the layout processing of the image data on the print medium, calculate offset information, where the offset information is position information about the position of the image data from the edge of the print medium, and Store the image data and the offset information for which the layout processing has been performed. Among them, when comparing the reference image data with the image printed on the print medium, in the case where the offset information is not 0, the offset information is used to determine the position of the reference image corresponding to the position of the scanned image, and the scanned image is obtained by scanning the image printed on the print medium.

10. The image forming system according to claim 9, wherein, The offset information includes position information on the position of the image data along the X direction from the edge of the print medium and position information on the position of the image data along the Y direction from the edge of the print medium.

11. The image forming system according to claim 9, wherein, The layout processing includes laying out the image data in the center of the print medium.

12. The image forming system according to claim 9, wherein,The layout processing includes comparing the size of the print medium with the image size of the image data, and rotating the image data in the case where the size of the print medium is different from the image size.

13. The image forming system according to claim 9, wherein, In the case where the printing device prints multi-page image data on the print medium, the offset information is stored page by page.

14. The image forming system according to any one of claims 9 to 13, the image forming system further comprising a reading device configured to read a sheet and generate image data, wherein, Compare the stored image data for which the layout processing has been performed with the image data generated by the reading device based on the offset information.

15. The image forming system according to claim 14, wherein, In the case where the offset information is zero, compare the entire image data for which the layout processing has been performed with the entire generated image data.

16. The image forming system according to claim 14, wherein, In the case where the offset information is not zero, compare the part of the image data for which the layout processing has been performed within the range based on the offset information with the part of the generated image data within the range based on the offset information.

Images