Image forming apparatus, control method thereof, and program

Abstract

To provide an image forming apparatus that reads a print position adjusting chart by ADF and specifies an appropriate image reading size including the paper edge of the chart.SOLUTION: An MFP 100 includes a printer 140 and an ADF unit 230. The MFP 100 controls the ADF unit 230 to read an image size larger than the sheet size of the print position adjusting chart 600 when printing the print position adjusting chart and acquiring a print position adjusting value from reading the same.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present invention relates to an image forming system that performs a process for adjusting the formation position of an image on a sheet. The image forming apparatus used in this image forming system can be applied to various apparatuses such as copiers, printers, FAX machines, and multifunctional machines thereof.

Background Art

[0002] Conventionally, in a printing apparatus (image processing apparatus) that forms an image on a sheet (paper), a function for adjusting the formation position of the image on the sheet (hereinafter referred to as "print position adjustment") has been used. In Patent Document 1, a technique for obtaining parameters for print position adjustment by printing an adjustment mark on a sheet and reading it with a reading device to obtain the positional relationship between the mark and the paper edge is disclosed. Also, as an example of the reading device, an automatic document feeder for sheets called ADF (Auto Document Feeder) is described. The parameters for print position adjustment are parameters that affect the cut shape for each cut sheet. Therefore, the operation of obtaining the parameters for print position adjustment is performed for each type of sheet.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In print position adjustment, since it is necessary to obtain the positional relationship between the mark and the paper edge, the paper edge of the sheet needs to be included in the image read from the ADF. In the ADF, since image reading is performed while transporting the sheet, a situation may occur where a part of the paper edge is missing depending on how the reading size of the image is specified when the sheet is transported. Therefore, it is desirable to appropriately specify the reading size of the image.

[0005] In view of the above-mentioned problems, the present invention aims to provide an image forming apparatus that reads a print position adjustment chart using an ADF and specifies an appropriate image reading size that includes the edges of the paper of the chart. [Means for solving the problem]

[0006] The present invention relates to an image forming apparatus comprising: an image forming unit for forming an image on a sheet; a reading unit for transporting the sheet and reading the image; means for causing the image forming unit to perform an image forming process for forming an image of a predetermined pattern on the sheet; reading means for reading the sheet on which the image of the predetermined pattern has been formed using the reading unit; and means for obtaining adjustment values ​​to be used for further image forming processing based on the reading results, wherein the reading means instructs the reading unit to read the image at an image size larger than the size of the sheet on which the image of the predetermined pattern has been formed. [Effects of the Invention]

[0007] According to the present invention, an image forming apparatus that reads a print position adjustment chart using an ADF can be provided that specifies an appropriate image reading size that includes the edges of the paper of the chart. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1(a) is a block diagram showing the configuration of the MFP100. Figure 1(b) is a block diagram showing the configuration of the scanner 130. Figure 1(c) is a block diagram showing the configuration of the printer 140. [Figure 2] This diagram shows the detailed configuration of the MFP100. [Figure 3] This diagram shows the sequence of operations for adjusting the print position. [Figure 4] Figure 4(a) shows the chart printing screen. Figure 4(b) shows the chart printing settings screen. Figure 4(c) shows the chart loading screen. [Figure 5] This is a flowchart illustrating the print position adjustment process. [Figure 6] Figure 6(a) shows the front surface of the adjustment chart. Figure 6(b) shows the back surface of the adjustment chart. Figure 6(c) is a diagram illustrating the measurement points on the adjustment chart. [Figure 7] This diagram shows the reading size in the sub-scanning direction for a standard document. [Figure 8] This figure shows the reading size in the sub-scan direction of the correction chart. [Figure 9] This diagram shows the reading size in the main scanning direction for a standard document. [Figure 10] This figure shows the reading size in the main scanning direction of the correction chart. [Figure 11] This is a flowchart illustrating the data loading process. [Figure 12] This diagram shows the loading size for correction charts of irregular or long sizes. [Figure 13] This is a flowchart illustrating the loading process for irregularly shaped and long-format documents. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described in detail below with reference to the drawings and examples. Note that the following embodiments are not intended to limit the invention as defined in the claims, and not all combinations of configurations and processes described in the embodiments are necessarily essential to the solution of the invention. Some or all of the configurations and processes described in the embodiments may be replaced with equivalents. Furthermore, some configurations and processes may be omitted.

[0010] (Example 1) In this embodiment, we will describe an image forming apparatus that obtains adjustment values ​​for image position (print position) by printing an adjustment chart (correction chart) on a sheet and reading it with an ADF (reading unit). In this embodiment, we will explain in detail the chart reading process.

[0011] Figure 3 is a sequence diagram showing an example of using this system. In this embodiment, the main communication takes place between the operator 300 and the MFP 100. Here, the state of the process starting from the state where the cassette library editing screen is displayed will be described.

[0012] In step 301 (hereinafter referred to as S301 etc.), the operator instructs the start of image position adjustment.

[0013] In S302, the MFP 100 determines to start image position adjustment and displays an image position adjustment screen.

[0014] In S303, the operator who has confirmed the image position adjustment screen sets the specification of the paper feed cassette to be adjusted, the method of executing the image position adjustment, etc., and instructs the execution of the image position adjustment. According to this instruction, the MFP 100 starts the image position adjustment process.

[0015] In S304, the MFP 100 performs adjustment chart output. The output adjustment chart (output) is stacked and placed on the paper discharge unit of the MFP 100. The number of adjustment charts output at this time may be one or a plurality. Also, the number of output adjustment charts may be a preset number or a number specified by the operator. Along with the output of the adjustment chart, the MFP 100 displays an adjustment chart reading screen.

[0016] In S305, the operator places the output adjustment chart on the placement unit 231 of the ADF unit 230 (document reading unit) according to the notification content of the reading screen and instructs the start of reading.

[0017] In S306, the MFP 100 performs a process of reading the adjustment chart placed on the image reading unit.

[0018] In S307, the MFP 100 obtains an image position adjustment value (parameter, printing position deviation amount) based on the image read from the adjustment chart.

[0019] In this embodiment, the image position of the paper feed cassette is adjusted as described above. Then, using the registered image position shift amount (adjustment value) for each paper feed cassette, image formation is performed as follows.

[0020] In S308, the operator uses the host computer to specify, configure, and execute print jobs to be output by the MFP100. For example, the operator configures a print job to print using sheets in a specific cassette, and then issues an execution command for the print job.

[0021] In S309, the host computer sends the print job specified by the operator to the MFP100.

[0022] In S310, the MFP100 executes a print job using paper in a specific cassette. At this time, the image position shift amount registered in the specific cassette is read from the cassette library and applied to the execution of the print job.

[0023] In S311, the MFP100 provides an output with adjusted image position.

[0024] As demonstrated in the above series of processes, once the image position adjustment process has linked the amount of image misalignment to the paper in the paper cassette, adjustments based on the amount of image misalignment will be made when a print job using this paper cassette is executed. Therefore, image position adjustment can be easily applied when executing a print job, reducing the workload on the operator.

[0025] <mfp> Next, we will explain the configuration of the MFP100. Figure 1(a) is a block diagram showing the configuration of the MFP100.

[0026] As shown in Figure 1(a), the MFP100 comprises a control unit 110, a scanner 130, a printer 140, and an operation unit 150.

[0027] Scanner 130 is a reading unit (reading device) that reads images from a document.

[0028] The printer 140 is an image forming unit (image forming device) that forms an image on a sheet.

[0029] The control unit 150 is a user interface (operation panel) that outputs information to the operator and receives instructions from the operator. The control unit 150 is equipped with a display (display unit) and a speaker for outputting information. The control unit 150 is equipped with a touch panel and hard keys for inputting information.

[0030] The control unit 110 is a controller that comprehensively controls each component of the MFP 100. The control unit 110 is connected to the scanner 130 and printer 140 and controls the input and output of image information. As a minimum controller configuration, the control unit 110 includes a CPU 111, RAM 112, and ROM 113. The control unit 110 also includes a storage unit 114, a network interface 115, a device interface 116, an operation interface 117, an image processing unit 118, and an image memory 119, and each component is connected by a communication means such as a bus.

[0031] The CPU111 is a general-purpose processor that performs various types of arithmetic operations.

[0032] RAM112 is volatile memory that functions as the working memory for CPU111.

[0033] ROM113 is a non-volatile memory that stores various programs, including the system's boot program.

[0034] The memory unit 114 is a storage device for storing information. For example, an HDD or SSD can be used for the memory unit 114. The memory unit 114 stores system software, image data, programs for controlling the operation of the MFP 100, and the like.

[0035] The program stored in the memory unit 114 is loaded into the RAM 112. The CPU 111 controls the operation of the MFP 100 based on the program loaded into the RAM 112.

[0036] The network interface 115 is a communication interface for connecting to a network. By connecting to LAN160, the network interface 115 handles the input and output of various information over the network. The network interface 115 may be an interface that supports wired communication, wireless communication, or both.

[0037] The device interface 116 connects the image input / output devices, such as the scanner 130 and printer 140, to the control unit 110 and performs synchronous / asynchronous conversion of image data.

[0038] The control unit interface 117 is an interface that connects the control unit 150 and the control unit 110. The control unit interface 117 outputs output information such as image data in order to display information on the display of the control unit 150. The control unit interface 117 also transmits input information entered by the user using the control unit 150 to the CPU 111.

[0039] The image processing unit 118 is a processor and circuit group specialized for image processing. The image processing unit 118 performs image processing on print data received via LAN. It also performs image processing on image data input and output from the device I / F 116.

[0040] The image memory 119 is a memory for temporarily expanding image data processed by the image processing unit 118.

[0041] The paper used for printing with the MFP100 is managed by the operator using a database called the cassette library. The cassette library is stored in the memory unit 114 or RAM 112, and is read and written to as needed by each software module. Details about the cassette library are omitted as they are publicly known.

[0042] <Scanner> Figure 1(b) is a block diagram showing the configuration of the scanner 130. Figure 2 is a diagram showing the detailed configuration of the MFP 100. The scanner 130 consists of a control unit 131 and a scanner mechanism 138. The control unit 131 includes a CPU 132, RAM 133, ROM 134, device I / F 135, image memory 136, and image processing unit 137.

[0043] The CPU 132 controls the operation of the scanner 130 and operates based on a program stored in the ROM 134 and loaded into the RAM 133. The device interface 135 connects to the control unit 110 and performs synchronous / asynchronous conversion of image data. The image memory 136 is a memory for temporarily loading image data input from the scanner mechanism 138. The control unit 131 transmits the image data stored in the image memory 136 to the control unit 110 based on an image transfer command received via the device interface 135.

[0044] The image processing unit 137 performs image processing on the image data expanded in the image memory 136.

[0045] The scanner mechanism 138 includes a pressure platen 240 for reading a document placed on a glass table, and an ADF unit 230 for transporting and reading a document 232 placed on a placement unit 231. In the ADF unit 230, the document placed on the placement unit 231 and detected by the detection sensor 233 is transported by the transport rollers of the transport path 235. The transported document is then scanned for images on both sides by an image sensor pair 234. The image sensor pair 234 uses two line sensors, one for the front and one for the back, with a longitudinal length in the depth direction of Figure 2 (the direction perpendicular to the transport direction in Figure 5, the direction of the spacing (A) in Figure 5). The line sensors are, for example, CIS. The longitudinal length of the image sensor pair 234 is configured to be longer than the maximum width of a document that can be read by the ADF. The image sensor for the back of the image sensor pair 234 may be replaced with an image sensor included in the pressure platen 240. The image sensor pair 234 uses multiple sensors arranged along the longitudinal direction to read pixel information from the original document one line at a time. By reading pixel information from multiple lines as the document is transported, the original image can be read.

[0046] <Printer> Figure 1(c) is a block diagram showing the configuration of the printer 140. The printer 140 consists of a control unit 131 and a printer mechanism 148. The control unit 141 includes a CPU 142, RAM 143, ROM 144, device I / F 145, image memory 146, and image processing unit 147.

[0047] The CPU 142 controls the operation of the printer 140 and operates based on a program stored in the ROM 144 and loaded into the RAM 143. The device interface 145 connects to the control unit 110 and performs synchronous / asynchronous conversion of image data. The image memory 146 is a memory for temporarily loading image data input from the control unit 110. The control unit 141 controls the printer mechanism 148 based on commands received via the device interface 145.

[0048] The printer mechanism 148 is a mechanical mechanism for performing image formation processing using an electrophotographic method. The printer mechanism 148 includes an engine control unit that controls each printing process (for example, paper feeding), and a control board housing that houses the printer controller.

[0049] The various mechanisms that make up the engine section include an optical processing mechanism for latent image development and processing of the image, a transfer processing mechanism for transferring the image to the sheet P, and a fixing processing mechanism for fixing the toner image transferred to the sheet P. Additionally, there is a paper feeding mechanism for the sheet P and a transport mechanism for transporting the sheet P.

[0050] During color image formation, the optical processing mechanism includes a Y (yellow) station 220, an M (magenta) station 221, a C (cyan) station 222, and a K (black) station 223. The toner images developed at each station are sequentially transferred onto an intermediate transfer medium 252, thereby forming a full-color visible image on the intermediate transfer medium 252 (primary transfer).

[0051] Next, the sheet P fed from the sheet (paper) storage unit 210 is transported, and the sheet P is pressed against the intermediate transfer body 252 by the transfer roller 251. At the same time, a bias with characteristics opposite to that of the toner is applied to the transfer roller 251. As a result, the visible image formed on the intermediate transfer body 252 is transferred to the sheet P that is transported by the paper feeding mechanism in synchronization with the transport direction of the sheet P (sub-scanning direction) (secondary transfer).

[0052] After the secondary transfer is complete, the sheet P passes through the fuser unit 260, where the toner transferred to the sheet P is heated and melted, fixing it as an image on the sheet P. In the case of double-sided printing, the sheet passes through the inversion unit 270, is inverted back, and is introduced back into the transfer unit to transfer the image on the back side to the sheet P. Then, the sheet P passes through the fuser unit 260 again in the same manner, where the toner image on the sheet P is heated and fixed, and the sheet is discharged to the paper discharge unit 280, completing the printing process.

[0053] <Image position adjustment> This section provides a detailed explanation of how to obtain adjustment values ​​for image position using an adjustment chart.

[0054] Figure 6(a) shows the front surface of the adjustment chart. Figure 6(b) shows the back surface of the adjustment chart. Figure 6(c) is a diagram illustrating the measurement points on the adjustment chart.

[0055] As shown in Figure 6(a), this explanation uses a chart format in which marks for image position adjustment are printed on the paper as an example.

[0056] Chart 600 includes a marker 601 and an identification patch 602 as an image of a predetermined pattern. Chart 603 includes a marker 601 and an identification patch 604.

[0057] Marker 601 is an image used to measure the image formation position on the paper, and is an isosceles triangle formed near the corners of the four corners of the sheet.

[0058] Identification patches 602 and 604 are images used to identify the front and back sides and orientation of the chart. Identification patch 602 is positioned closer to the center of the sheet on both the short and long sides than marker 601.

[0059] This chart is used to measure the intervals (A), (B) and intervals (G) to (N) in Figure 6(c). Intervals (A) and (B) are the main scan direction length and sub scan direction length of the chart, respectively, and the ideal length is the paper length defined in the paper library.

[0060] The front and back sides and orientation of the chart surface are determined by the position and orientation of identification patches 602 and 604. For example, if the image detected by the identification patch sampling process is identification patch 602, that side is determined to be the front side of the chart surface. If the image detected by the identification patch sampling process is identification patch 604, that side is determined to be the back side of the chart surface. Furthermore, if the position of identification patch 602 or 604 is in the upper right region, the orientation is determined to be correct. On the other hand, if the position of identification patch 602 or 604 is in the lower left region, the orientation is determined to be reversed.

[0061] The interval (G) to interval (N) is the distance from the corner of marker 601 to the nearest edge of the paper. As shown in Figure 6(d), each measured interval is compiled into a table as a measurement value and stored in RAM112. These measurement values ​​are used to calculate the adjustment value.

[0062] To obtain the adjustment values ​​mentioned above, the MFP100 in this embodiment performs a series of processes for the adjustment function. Figure 5 is a flowchart of the print position adjustment process.

[0063] In S501, CPU111 executes the chart printing process.

[0064] In one step of the chart printing process, the CPU 111 displays the image position adjustment screen 404 on the operation unit 150. As shown in Figure 4(a), the image position adjustment screen 404 includes a print start button 410 and multiple cassette information, including cassette information 408 and 409. Here, cassette information 408 shows an example of cassette information where image position adjustment cannot be started due to reasons such as no paper. Cassette information 409 shows an example of cassette information where image position adjustment cannot be started. It is desirable that the display method differs depending on whether the conditions for starting image adjustment are met. The user specifies the cassette information to be targeted for image position adjustment from among the multiple cassette information and selects the print start button 410. Upon receiving this instruction, the CPU 111 instructs the printer 140 to perform image formation based on the chart image for a predetermined number of copies. As a result, the output unit 280 outputs a predetermined number of charts as shown in Figures 6(a) and 6(b). Furthermore, the number of charts output with a single image position adjustment may be changed according to user instructions.

[0065] For example, as shown in Figure 4(b), the CPU 111 displays the output count setting screen 411 on the operation unit 150. The output count setting screen 411 includes an input form 412 for entering the set value for the number of output pages and an OK button. When the number of output pages is entered in the input form 412 and the OK button is subsequently selected, the CPU 111 stores the number set in the input form 412 in the RAM 112. This information is used when the print start button 410 is selected.

[0066] In S502, CPU111 executes the chart loading process.

[0067] In one step of the chart printing process, the CPU 111 displays the chart reading screen 401 on the operation unit 150. As shown in Figure 4(c), the chart reading screen 401 includes guidance information 402 indicating the direction of chart reading and a start reading button 403. When the chart is set on the mounting unit 231 and the start reading button 403 is selected, the CPU 111 starts the reading process.

[0068] In S503, CPU111 performs identification patch sampling.

[0069] The identification patch sampling process involves determining the front and back sides and orientation of the chart.

[0070] In S504, CPU111 performs marker sampling.

[0071] In marker sampling, a process is performed to measure the image formation positions of the chart.

[0072] In S505, CPU111 performs paper edge sampling.

[0073] In the paper edge sampling process, the position of the paper edge, particularly the corners, is detected. Methods for detecting the paper edge include detecting the shading of the paper edge and observing the color difference between the paper edge and the area outside the paper. These known techniques will not be explained in this embodiment.

[0074] In S506, CPU111 performs coordinate transformation processing.

[0075] In the coordinate transformation process, the measured values ​​for each interval are calculated based on the marker coordinate information obtained in S504 and the paper edge coordinate information based on S505. In addition, the coordinate information is corrected as needed when calculating the measured values.

[0076] In S507, CPU 111 executes the correction value calculation process. In S507, CPU 111 calculates the correction value (adjustment value) based on the information obtained from the previous processing. When the calculation of the correction value is completed successfully, a notification is sent indicating that the correction is complete.

[0077] <Image loading process> The image reading process will now be explained. In this embodiment, image reading is performed over an area wider than the original document size so that the sheet edges can be properly detected when reading the chart. In Figure 6(c), intervals (C) to (F) indicate the length of the margin area for reading the chart as an image including the sheet edges. Interval (C) indicates the length of the margin area at the leading edge in the main scanning direction of the chart, interval (D) indicates the length of the margin area at the trailing edge in the main scanning direction, interval (E) indicates the length of the margin area at the leading edge in the sub-scanning direction of the chart, and interval (F) indicates the length of the margin area at the trailing edge in the sub-scanning direction. These margin areas are added to enable the scanner 130 to read an image including the paper edge (sheet edge) even if the chart is transported at an angle when reading the chart from the ADF unit 230. Therefore, the lengths of intervals (C) to (F) should be defined according to the transport performance of the scanner 130. For example, intervals (C) to (F) may all be the same length, or they may all be different lengths.

[0078] Regarding intervals (C) to (F), Figures 7 to 10 will be used to explain the difference between chart loading and normal loading processes.

[0079] <Read control in the sub-scanning direction> First, using Figures 7 and 8, we will explain the difference in the sub-scanning direction of the sheet during chart loading and normal loading.

[0080] Figure 7 illustrates the reading size in the sub-scan direction when performing a normal reading process. Figure 7 schematically shows the relationship between the read image and the synchronization signal.

[0081] In Figure 7, sheet 700 indicates the sheet to be read by scanner 130. Spacing (A) and spacing (B) indicate the length of the sheet to be read in the main scanning direction and the length of the sheet in the sub-scanning direction, respectively.

[0082] The synchronization signal 702 is a synchronization signal used to control the CPU 111's reception of the image read by the scanner 130 via the device I / F 116.

[0083] The timing waveform 703 indicates the timing at which the CPU 111 controls the scanner 130 to start receiving the read image via the device I / F 116, as part of the synchronization signal 702. The timing waveform 703 indicates the timing for the sub-scanning direction length. After a predetermined time lag (the time required for sheet transport for interval (O)) has elapsed from this timing waveform 703, the scanner 130 starts transmitting the read image to the device I / F 116. The CPU 111 receives this. In detail, after an interval of interval (O) from the timing waveform 703, the CPU 111 receives the read image from the scanner 130 via the device I / F 116 for a section of interval (P) corresponding to interval (B), which is the length of the sub-scanning direction of the sheet. In order to receive the image for the section of interval (P), the CPU 111 instructs the scanner 130 to start reading after specifying the interval (B), which is the length of the sub-scanning direction of the sheet, as the reading size for the sub-scanning direction. Subsequently, once the reading for the specified sub-scanning direction, which is the interval (B) length, is complete, reading from the sensor stops.

[0084] By controlling the timing of image reading in this way, it is possible to read images from the leading edge 701 of sheet 700 for a distance of interval (B). In other words, it is possible to read images that are exactly the size of the original document.

[0085] In contrast to this normal reading process, the reading process for the print position adjustment chart involves timing control of image reading that takes into account the margin in the sub-scanning direction.

[0086] Figure 8 illustrates the reading size in the sub-scanning direction when reading a print position adjustment chart. Figure 8 schematically shows the relationship between the read image and the synchronization signal.

[0087] In Figure 8, sheet 800 shows the print position adjustment chart read by scanner 130. Spacing (A) and spacing (B) indicate the length of the chart in the main scanning direction and the length in the sub-scanning direction, respectively. Spacings (C) to (F) indicate the length of the margin area for scanning the image of the chart, including the paper edge, from scanner 130.

[0088] The synchronization signal 803 is a synchronization signal used to control the CPU 111's reception of the image read by the scanner 130 via the device I / F 116.

[0089] The timing waveform 804 indicates the timing at which the CPU 111 begins receiving the read image from the scanner 130 via the device I / F 116, as part of the synchronization signal 803. The timing waveform 804 indicates the timing for the sub-scanning direction length. After a predetermined time lag (the time required for sheet transport for interval (O)) has elapsed from this timing waveform 804, the scanner 130 begins transmitting the read image to the device I / F 116, and the CPU 111 receives it. In detail, the CPU 111 receives the read image from the scanner 130 via the device I / F 116 after an interval of interval (O) from the timing waveform 804. The read image at this time has a length corresponding to the interval (Q) which is the length of the sub-scanning direction of the sheet: interval (B) + margin area interval (E) + margin area interval (F). In order to receive an image for the interval (Q), the CPU 111 instructs the scanner 130 to start reading after specifying the read size in the sub-scanning direction in advance. The sub-scanning direction length is the interval (B) + the interval of the margin area (E) + the interval of the margin area (F).

[0090] By adjusting the timing waveform 804 of the synchronization signal 803 in this way to control the timing of image reading, it is possible to start reading images of the gap (E) in the margin area at the leading edge 801 of the sub-scanning direction of the chart before the leading edge 801 reaches the reading sensor. After that, when the leading edge 801 reaches the reading sensor, the chart is read. Then, even after reading images for the gap (B) in the sub-scanning direction of the chart, images of the gap (F) in the margin area at the trailing end of the sub-scanning direction are read. Once image reading for the length of the gap (F) from the trailing end 802 of the chart is complete, reading from the sensor is stopped.

[0091] As explained above in Figures 7 and 8, in the reading process of the print position adjustment chart, the timing of image reading in the sub-scanning direction is controlled to be earlier compared to the normal reading process. Specifically, in the reading process of the print position adjustment chart, the timing from the start of transporting the document placed on the placement unit 231 to the start of image reading is controlled to be earlier by interval (E) compared to the normal reading process.

[0092] <Main scanning direction reading control> Next, using Figures 9 and 10, we will explain the difference in the main scanning direction of the sheet during chart loading and normal loading.

[0093] Figure 9 illustrates the reading size in the main scanning direction when performing a normal reading process. Figure 9 schematically shows the relationship between the read image and the synchronization signal.

[0094] In Figure 9, sheet 900 indicates the sheet to be read by scanner 130. Interval (A) and interval (B) indicate the length of the sheet to be read in the main scanning direction and the length of the sheet in the sub-scanning direction, respectively. Synchronization signal 902 is a synchronization signal used to control the CPU 111 to receive the image read by scanner 130 via device I / F 116. Timing waveform 903 is a synchronization signal indicating the start timing of image reading in the main scanning direction. The image sensor pair 234 mounted on scanner 130 has a number of sensors arranged in a row along the main scanning direction.

[0095] Pixel information acquired by each sensor of the image sensor pair 234 is output sequentially to the device I / F 116 from the sensor on one end of the image sensor pair 234 to the sensor on the other end. Pixel output by the image sensor pair 234 occurs at regular time intervals for each line. Therefore, by controlling the pixel reading timing using a synchronization signal, it becomes possible to read pixels from an intermediate point within a single line output by the image sensor pair 234.

[0096] After a predetermined time (the time required to read out pixels for interval (R)) has elapsed from the timing waveform 903, pixel information of consecutive sensors starting from a sensor in the middle of the image sensor pair 234 is transmitted to the CPU 111 via the device I / F 116. In detail, after a time interval of interval (R) from the timing waveform 903, the CPU 111 receives the read image from the scanner 130 via the device I / F 116 for a section of interval (S) corresponding to interval (A), which is the length of the main scanning direction of the sheet. In order to receive the image for the section of interval (S), the CPU 111 instructs the scanner 130 to start reading after specifying the interval (A), which is the length of the main scanning direction of the sheet, as the reading size for the main scanning direction. Subsequently, when reading for the length of interval (B), which is the specified reading size for the sub-scanning direction, is completed, the reading of pixels on that line is stopped.

[0097] By controlling the timing of image reading in this way, it is possible to read images from the left edge of sheet 900, starting from 901, for a distance of interval (A). In other words, it is possible to read images that are exactly the size of the original document.

[0098] In contrast to this normal reading process, the reading process for the print position adjustment chart involves timing control of image reading that takes into account the margin in the main scanning direction.

[0099] Figure 10 illustrates the reading size in the main scanning direction when performing the reading process of the print position adjustment chart. Figure 10 schematically shows the relationship between the read image and the synchronization signal.

[0100] In Figure 10, sheet 1000 indicates the sheet to be read by scanner 130. Interval (A) and interval (B) indicate the length in the main scanning direction and the length in the sub-scanning direction of the sheet to be read, respectively. Synchronization signal 1002 is a synchronization signal used to control the reception of the image read by scanner 130 to CPU 111 via device I / F 116. Timing waveform 1003 is a synchronization signal indicating the start timing of image reading in the main scanning direction.

[0101] After a predetermined time (the time required to read out pixels for interval (R)) has elapsed from the timing of the timing waveform 1003, pixel information of consecutive sensors starting from a sensor in the middle of the image sensor pair 234 is transmitted to the CPU 111 via the device I / F 116. Specifically, the CPU 111 receives the read image from the scanner 130 via the device I / F 116 after a time interval of interval (R) from the timing waveform 804. The read image has a length corresponding to the interval (T) which is the length of the main scanning direction of the sheet, consisting of interval (A) + margin interval (C) + margin interval (D). In order to receive an image for the interval (T), the CPU 111 instructs the scanner 130 to start reading after specifying the length of the main scanning direction of the sheet as the read size in the main scanning direction. The length of the main scanning direction is interval (A) + margin area interval (C) + margin area interval (D). Subsequently, once the reading of pixels for the specified interval (T), which is the reading size in the main scanning direction, is complete, the reading of pixels in that line is stopped.

[0102] By adjusting the timing waveform 1003 of the synchronization signal 1002 in this way to control the timing of image reading, it is possible to start reading images of the interval (C) in the margin area at the left end of the main scanning direction of the chart before the left end 1001 of the main scanning direction of the chart. Subsequently, pixels at the position corresponding to the left end 1001 are read, and pixels corresponding to the chart are read. After reading images for the interval (A) in the main scanning direction of the chart, images of the interval (D) in the margin area at the rear end of the main scanning direction are read. When image reading of the length of interval (D) from the rear end of the chart is completed, pixel reading in that line is stopped.

[0103] As explained above in Figures 9 and 10, the loading process for the print position adjustment chart is controlled to load the image in the main scanning direction earlier compared to the normal loading process.

[0104] <Loading process> Figure 11 shows a detailed flow of the reading process.

[0105] This reading process corresponds to process S502 in Figure 5. The flow shown in Figure 11 is implemented by the control unit 110. More specifically, it is implemented by loading the corresponding program from the ROM or storage unit 114 into the RAM 112, and then executing it on the CPU 111.

[0106] In S1101, the CPU 111 determines what type of loading screen is displayed on the operation unit 150. In other words, the CPU 111 determines what type of loading function is being called.

[0107] If the currently displayed screen is the screen for loading the print position adjustment chart (S1101:YES), CPU 111 proceeds to S1102.

[0108] If the displayed screen is different from the screen for reading the print position adjustment chart, for example, if it is a normal screen corresponding to the function of saving or sending scanned images (S1101:NO), the CPU 111 proceeds to S1105.

[0109] In S1105, the CPU 111 is in normal reading mode, so no special specifications are made, and it directly specifies the size of the document to be read to the scanner 130 using the size information obtained using user input or the sensor of the mounting unit 231.

[0110] On the other hand, in S1102, the CPU 111 instructs the scanner 130 to read images even in the margins outside the chart area by specifying the mode for reading the print position adjustment chart.

[0111] In S1103, the CPU 111 acquires the size information of the document to be scanned, and based on the acquired size information of the document to be scanned and the size information of the margin area including the edges of the chart, (by adding them together) it specifies the scanning size to the scanner 130. The size information of the document to be scanned is acquired from the paper information corresponding to the cassette specified on screen 404. Note that the size information of the document to be scanned may also be acquired using user input or the sensor of the mounting unit 231.

[0112] In S1104, the CPU 111 instructs the scanner 130 to perform a read operation based on the specified mode and read size.

[0113] <Remarks> As explained above, according to this embodiment, when reading the print position adjustment chart using the ADF, the image is read with the margins included in the image size. Therefore, even if the document transported by the ADF is tilted, the chart image including the paper edge, which is necessary to obtain the positional relationship between the mark and the paper edge, can be appropriately obtained. In addition, since the image size including the margins is smaller than the maximum readable size of the image sensor pair 234, the image reading speed can be increased. Although this embodiment describes its application to print position adjustment, it can be similarly applied to other functions that have a process of reading a chart with an ADF and performing correction.

[0114] (Example 2) Example 1 described an image forming apparatus that supports the reading process of a standard-sized print position adjustment chart. Example 2 describes an image forming apparatus that further supports the print position adjustment of long and irregular sizes. The configuration of the image forming apparatus in Example 2 is the same as that in Example 1, except for the parts that are characteristic of Example 2. Therefore, the same reference numerals are used for similar components, and their detailed explanation is omitted.

[0115] <Image loading process> Figure 12 shows the reading size of a correction chart of an irregular or long size. Chart 1200 shown in Figure 12 is an example of a chart for image position adjustment, schematically representing a sheet of paper with marks for image position adjustment printed on it. Here, Chart 1200 is assumed to be a sheet of paper of an irregular or long size with marks printed on it.

[0116] In this embodiment, "non-standard size" refers to a paper size that is not included in the standard size range and does not exceed the maximum standard size that the MFP100 can print on. On the other hand, in this embodiment, "long size" refers to a paper size that is not included in the standard size range and exceeds the maximum standard size that the MFP100 can print on. In the MFP100, the maximum long size that the scanner 130 can read is defined and is set to 1000 mm in this embodiment. Also, in this embodiment, the explanation will assume that the maximum standard size that the MFP100 can print on is A3 size, but it may be a different size.

[0117] The CPU 111 obtains information necessary for image position adjustment by analyzing the position of the marker 1201, and determines the front / back and mounting orientation of the surface by detecting the identification patch 1202.

[0118] In Figure 12, intervals (A') and (B') are the main scanning direction length and sub-scanning direction length of the chart, respectively, with the ideal length being the paper length defined in the paper library. On the other hand, interval (G') indicates the length in the sub-scanning direction for image reading when the scanner 130 reads an irregularly shaped or long chart. When reading an irregularly shaped or long chart, the size of the chart cannot be determined until the scanner 130 actually performs the reading. Therefore, the scanner 130 reads the sub-scanning direction length as interval (G'), which is the sub-scanning length of the largest irregularly shaped or long chart.

[0119] The intervals (C') to (F') indicate the length of the margin area for scanner 130 to read the image, including the edges of the chart paper.

[0120] Spacing (C') indicates the length of the margin area at the leading edge of the chart in the main scanning direction, spacing (D') indicates the length of the margin area at the trailing edge of the chart in the main scanning direction, spacing (E') indicates the length of the margin area at the leading edge of the chart in the sub-scanning direction, and spacing (F') indicates the length of the margin area at the trailing edge of the sub-scanning direction.

[0121] The margin area is added to ensure that the scanner 130 can read the image including the edges of the chart even if the chart is transported at an angle when reading the chart from the ADF unit 230. For this reason, the lengths of the margin area intervals (C') to (F') are determined according to the transport performance of the scanner 130. The intervals (C') to (F') may all be the same length, or they may all be different lengths.

[0122] As mentioned above, when reading irregularly shaped or long-size charts, the scanner 130 reads the length in the sub-scanning direction as the interval (G') of the sub-scanning length of the largest irregularly shaped or long-size chart.

[0123] When reading the print position adjustment chart, the CPU 111 instructs the scanner 130 to read the image, including the margin area, by specifying the reading size in the sub-scanning direction. The reading size in the sub-scanning direction is the length obtained by adding the margin area spacing at the leading edge (E') and the margin area spacing at the trailing edge (F') of the sub-scanning length (G') of the maximum size of the irregular or long sub-scanning length.

[0124] In response to this, when instructed to start reading, the scanner 130 transports the chart placed in the ADF unit 230 and starts reading images of the margin area (E') at the leading edge 1203 in the sub-scanning direction of the chart before it reaches the reading sensor. Then, when the leading edge 1203 reaches the reading sensor, it starts reading the chart. After reading images of the maximum sub-scanning length (G') for irregularly shaped or long charts, it reads images of the margin area (F') at the trailing end in the sub-scanning direction, and stops reading from the sensor once image reading including the margin area is complete.

[0125] When scanning a chart of an irregular or long size, the scanner 130 detects when the trailing end 1204 of the chart passes the scanning sensor and detects the actual sub-scanning length interval (B') of the chart. The scanner 130 notifies the CPU 111 of this detected actual sub-scanning length interval (B') of the chart. When the CPU 111 receives the image scanned by the scanner 130 via the device I / F 116, it receives the image in intervals of the actual sub-scanning length interval (B') notified by the scanner 130, thereby enabling the scanning of an irregular or long size image.

[0126] In reading the print position adjustment chart, the CPU 111 receives the read image for the interval (H') from the scanner 130 via the device I / F 116.

[0127] The device I / F116 receives the read image for intervals (H') which are the sum of the notified actual sub-scan length interval (B'), the margin area interval at the leading edge of the sub-scan direction (E'), and the margin area interval at the trailing edge of the sub-scan direction (F'). This allows for image reading, including the margin areas, even for charts of irregular or long sizes.

[0128] Figure 13 is a flowchart of the reading process for irregularly shaped and long-sized files. This reading process corresponds to process S502 in Figure 5. The flow shown in Figure 13 is implemented by the control unit 110. More specifically, it is implemented by loading the corresponding program from the ROM or storage unit 114 into the RAM 112, and then executing it on the CPU 111.

[0129] In S1301, the CPU 111 determines what type of loading screen is displayed on the operation unit 150. In other words, the CPU 111 determines what type of loading function is being called.

[0130] If the currently displayed screen is the screen for loading the print position adjustment chart (S1301:YES), CPU 111 proceeds to S1302.

[0131] If the displayed screen is different from the screen for reading the print position adjustment chart, for example, if it is a normal screen corresponding to the function of saving or sending scanned images (S1301:NO), the CPU 111 proceeds to S1315.

[0132] In S1315, the CPU 111 is in normal reading mode, so no special specifications are made, and it directly specifies the reading size to the scanner 130 using the size information of the document to be read, which is obtained using user input or the sensor of the mounting unit 231.

[0133] Then, in S1316, the CPU 111 instructs the scanner 130 to perform a read operation based on the specified read size.

[0134] In S1302, the CPU 111 determines whether the print position adjustment chart to be read is of a standard size. If it is determined that the print position adjustment chart is of a standard size (S1302: YES), the CPU 111 proceeds to S1303. If it is determined that the print position adjustment chart is not of a standard size (S1302: NO), the CPU 111 proceeds to S1306.

[0135] In S1303, the CPU 111 instructs the scanner 130 to read images even in the margins outside the chart area by specifying the mode for reading the print position adjustment chart.

[0136] In S1304, the CPU 111 acquires the size information of the document to be scanned, and based on the acquired size information of the document to be scanned and the size information of the margin area including the edges of the chart, (by adding them together) specifies the scanning size to the scanner 130. The size information of the document to be scanned is acquired from the paper information corresponding to the cassette specified on screen 404. Note that the size information of the document to be scanned may also be acquired using user input or the sensor of the mounting unit 231.

[0137] In S1305, the CPU 111 instructs the scanner 130 to perform a read operation based on the specified mode and read size.

[0138] In S1307, the CPU 111 instructs the scanner 130 to read images even in the margins outside the chart area by specifying the mode for reading the print position adjustment chart.

[0139] In S1312, the CPU 111 instructs the scanner 130 to read images even in the margins outside the chart area by specifying the mode for reading the print position adjustment chart.

[0140] In S1306, the CPU 111 determines whether the print position adjustment chart to be read is of an irregular size or a long size. If it is determined that the print position adjustment chart is of an irregular size (S1306: YES), the CPU 111 proceeds to S1307.

[0141] If the CPU 111 determines that the print position adjustment chart is not of a non-standard size, i.e., a long size (S1307: NO), the CPU 111 proceeds to S1312.

[0142] In S1307, the CPU 111 instructs the scanner 130 to read images even in the margins outside the chart area by specifying the mode for reading the print position adjustment chart.

[0143] In S1308, CPU111 is instructed to perform the operation of reading an image of an irregular size.

[0144] In S1309, the CPU 111 specifies to the scanner 130 the size obtained by adding the size of the margin area including the edges of the paper to the maximum standard size that the scanner 130 can read.

[0145] In S1312, the CPU 111 instructs the scanner 130 to read images even in the margins outside the chart area by specifying the mode for reading the print position adjustment chart.

[0146] In S1313, the command is given to perform the operation of reading a long-size image.

[0147] In S1314, the CPU 111 specifies to the scanner 130 the size obtained by adding the size of the margin area including the edges of the paper to the maximum long document size that the scanner 130 can read (S1314).

[0148] In S1310, the CPU 111 instructs the scanner 130 to read the print position adjustment chart.

[0149] In S1311, the CPU 111 acquires the read image with a size obtained by adding the size of the margin area to the actual sub-scan length of the chart notified by the scanner 130.

[0150] <Remarks> As described above, when reading a non-standard or long-size print position adjustment chart from the ADF and performing image position adjustment, it is possible to read a chart image including the paper edge, which is necessary to obtain the positional relationship between the mark and the paper edge. Although this embodiment describes its application to print position adjustment, it can be similarly applied to other functions that read charts in the ADF and perform corrections.

[0151] (Other examples) The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0152] Furthermore, the present invention may be applied to a system consisting of multiple devices or to a device consisting of a single device. For example, the functionality may be realized by configuring a part of the software module to run on an external server and obtaining the results processed on the external server. For example, the storage unit for storing data may be provided within the external server.

[0153] Although the example described its application to image position adjustment, it can be similarly applied to other functions that read charts with an ADF and perform corrections.

[0154] The present invention is not limited to the embodiments described above, and various modifications (including organic combinations of each embodiment) are possible based on the spirit of the invention, and these are not excluded from the scope of the invention. In other words, all configurations that combine the above-described embodiments and their modified forms are included in the present invention.

[0155] The meanings of the abbreviations used in the examples are as follows: ADF stands for Auto Document Feeder. ASIC stands for Application Specific Integrated Circuit. CIS stands for Contact Image Sensor.

[0156] CPU stands for Central Processing Unit. FAX stands for Facsimile. HDD stands for Hard Disk Drive. HTML stands for Hyper Text Markup Language. LAN stands for Local Area Network. MFP stands for Multi Function Peripheral. PC stands for Personal Computer. RAM stands for Random-Access Memory. ROM stands for Read-Only Memory. SSD stands for Solid State Drive.< / mfp>

Claims

1. an image forming means for forming an image on a sheet; A conveying means for conveying the sheet in a conveying direction; a reading means for reading the sheet conveyed in the conveying direction by the conveying means with an image sensor; and a control means, The control means causes the image forming unit to execute an image forming process for forming an image of a predetermined pattern on a sheet, conveying the sheet on which the image of the predetermined pattern is formed in the conveying direction; causing the reading means to start a reading process before a leading edge of the sheet on which the image of the predetermined pattern is formed reaches the image sensor, based on a size of the sheet on which the image of the predetermined pattern is formed; and acquiring an adjustment value for an image forming process based on the result of reading the image.

2. 2. The image forming apparatus according to claim 1, wherein the sheet on which the image of the predetermined pattern is formed is a sheet of a standard size.

3. 2. The image forming apparatus according to claim 1, wherein the sheet on which the image of the predetermined pattern is formed is a sheet of a non-standard size.

4. 2. The image forming apparatus according to claim 1, wherein the sheet on which the image of the predetermined pattern is formed is a long sheet.

5. 5. The image forming apparatus according to claim 1, wherein the image of the predetermined pattern includes markers near each of the four corners of the sheet.

6. 6. The image forming apparatus according to claim 5, wherein the marker is a triangle.

7. 6. The image forming apparatus according to claim 5, wherein the marker is an isosceles triangle.

8. 8. The image forming apparatus according to claim 1, wherein the predetermined pattern further comprises an identification patch, the identification patch being a patch for determining whether a sheet is a front or back side.

9. 8. The image forming apparatus according to claim 1, wherein the predetermined pattern further comprises an identification patch, the identification patch being a patch for determining the orientation of the sheet.

10. A display unit for displaying information; 10. The image forming apparatus according to claim 1, further comprising: a display control unit that causes the display unit to display a screen prompting the user to place the sheet on which the image of the predetermined pattern is formed on the reading unit.

11. 11. The image forming apparatus according to claim 10, wherein the screen includes information on an orientation in which the sheet on which the image of the predetermined pattern is formed should be placed.

12. an image forming unit that forms an image on a sheet; a conveying section that conveys the sheet in a conveying direction; a reading unit that reads the sheet conveyed in the conveying direction by the conveying unit using an image sensor, causing the image forming unit to execute an image forming process for forming an image of a predetermined pattern on a sheet; conveying the sheet on which the image of the predetermined pattern is formed in the conveying direction; causing the reading unit to start a reading process before a leading edge of the sheet on which the image of the predetermined pattern is formed reaches the image sensor based on a size of the sheet on which the image of the predetermined pattern is formed; and obtaining an adjustment value for an image forming process based on the result of reading the image.

13. A program for causing a computer to execute the control method for an image forming apparatus described in claim 12.

Images