Information processing apparatus, information processing method, and program

Abstract

To accurately detect marks formed on a recording medium.SOLUTION: An image forming apparatus 100 detects a plurality of detection marks of different colors formed on a roll sheet 111 based on a measurement result obtained by reading the roll sheet 111 being conveyed, and then selects, from among the plurality of detection marks, a detection mark to be used for specifying a position of an image to be printed on the roll sheet 111 based on a measurement value of each of the plurality of detection marks.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to identifying a location on a recording medium. [Background technology]

[0002] A conventional method for identifying the position of an image to be printed involves printing a special mark and detecting the printed detection mark. Patent Document 1 discloses a method for detecting the position of an area detection mark from brightness information and color difference information obtained by reading, with a scanner, an area including the area detection mark from a handwritten manuscript sheet having a mark for detecting the area of ​​a handwritten image. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-41673 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the method disclosed in Patent Document 1 has a problem in that the mark cannot be detected unless the difference in luminance or color between the background color of the paper and the area detection mark is equal to or greater than a predetermined amount.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to accurately detect marks formed on a recording medium. [Means for solving the problem]

[0006] The present invention is characterized by having a detection means for detecting a plurality of marks of different colors formed on the recording medium based on measurement results obtained by reading the recording medium being transported, and a selection means for selecting the mark to be used to identify the position of an image to be printed on the recording medium based on the measurement values ​​of each of the plurality of marks. [Effects of the Invention]

[0007] According to the present invention, marks formed on a recording medium can be detected with high accuracy. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of the overall configuration of an image forming system. [Figure 2] FIG. 1 is a block diagram illustrating an example of the configuration of an image forming apparatus. [Figure 3] 10 is a flowchart showing a mark selection process. [Figure 4] FIG. 10 is a diagram showing an example of a detection mark. [Figure 5] FIG. 10 is a diagram for explaining detection of a detection mark. [Figure 6] 10 is a flowchart showing a mark determination process. [Figure 7] 10 is a flowchart showing a mark determination process. [Figure 8] 10 is a flowchart showing a mark determination process. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0010] FIG. 1 shows an example of the overall configuration of an image forming system according to this embodiment. The image forming system 200 forms a print image on roll paper 111. The roll paper 111 is continuous paper and is an example of a recording medium. The image forming system 200 includes an image forming apparatus 100 that controls the entire system, a paper feeder 104, a first printing apparatus 115 that prints print images, a second printing apparatus 116 that prints position detection marks before printing the print images, and a paper discharge apparatus 105. The image forming apparatus 100 includes an operation display unit 206. The operation display unit 206 is, for example, a UI operation panel that displays a UI (user interface) and accepts various input operations from the user. The printing method of the first printing apparatus 115 and the second printing apparatus 116 may be electrophotographic or inkjet.

[0011] The paper feeder 104 is a device that supplies roll paper 111 to the second printing device 116 and the first printing device 115. Before printing begins, the roll paper 111 wound around the paper tube of the paper feeder 104 is passed through to the paper discharge device 105 and set. When setting, the leading edge of the roll paper 111 is passed over the oblique light correction device 110. The paper feeder 104 rotates the paper tube of the roll paper 111 around a rotation axis 117, and transports the roll paper 111 wound around the paper tube towards the second printing device 116 at a constant speed via multiple rollers (transport rollers, paper feed rollers, etc.). The roll paper 111 transported to the second printing device 116 is then transported to the first printing device 115.

[0012] The paper discharge device 105 is a device that winds up the roll paper 111 transported from the first printing device 115 into a roll around a paper tube. The paper discharge device 105 winds up the transported roll paper 111 as a finished product onto a paper tube that rotates around a rotation axis 118 at a constant speed via multiple rollers (transport rollers, paper discharge rollers, etc.).

[0013] The second printing device 116 is a device that prints position detection marks on the roll paper 111 transported from the paper feed device 104. The second printing device 116 is equipped with a second recording unit 103 that prints using special color inks (e.g., white ink) other than the basic color inks (e.g., CMYK inks). In this embodiment, the special color inks include multiple inks of different colors. The second printing device 116 uses the second recording unit 103 to form detection marks on the roll paper 111 in positions that do not overlap with the printed image printed by the first printing device 116. Multiple detection marks corresponding to the multiple inks used by the second recording unit 103 are formed in predetermined positions on the roll paper 111. The roll paper 111 printed by the second recording unit 103 is transported to the first printing device 115 via a drying device 112 and cooling devices 113 and 114.

[0014] The first printing device 115 is a device that prints a print image on roll paper 111 transported from the second printing device 116. The first printing device 115 is equipped with a first recording unit 102 that prints using basic color inks. The roll paper 111 transported from the second printing device 116 first passes through a sensor 120 that detects detection marks on the roll paper 111. The second printing device 115 then uses the first recording unit 102 to form a print image on the roll paper 111. The printing position of the print image is identified using the detection marks detected by the sensor 120.

[0015] The roll paper 111 printed by the first recording unit 102 passes through the drying device 106 and cooling devices 108 and 109, and then passes through the connected scanner device 107. After passing through the connected scanner device 107, the roll paper 111 is transported to the paper discharge device 105.

[0016] When image forming apparatus 100 receives a print start operation for an image formation job (hereinafter referred to as a job) from operation display unit 206, it controls each device constituting image forming system 200 to process the job. Image forming apparatus 100 is an example of an information processing apparatus.

[0017] The image forming apparatus 100 may also use a scanner device (not shown) to read the printed material and inspect it for defects. For example, it may check whether printing is possible without any ink ejection defects from the ink ejection nozzles. If there is an ejection defect, the image forming apparatus 100 stops processing the job. Inspection methods include printing a detection pattern and reading it with a scanner device, reading the printed image with a camera or scanner device, and monitoring the ejection status of the ink ejection nozzles. The sensor 120 may also have the functions of the scanner device described above.

[0018] Next, an example of the configuration of the image forming apparatus 100 will be described with reference to FIG. 2(a) shows the hardware configuration of the image forming apparatus 100. The image forming apparatus 100 includes a paper transport unit 201, an image forming unit 202, a communication unit 203, a control unit 204, a storage unit 205, an operation display unit 206, a sensor connection I / F 207, a paper feed control unit 208, and a take-up control unit 209. Under the control of the control unit 204, the paper transport unit 201 controls the transport mechanism inside the image forming system 200. The paper transport unit 201 transports the roll paper 111 supplied from the paper feeder 104 to the second printing device 116, the first printing device 115, and the paper discharge device 105 at a set printing speed, for example, by using multiple rollers.

[0019] Under the control of the control unit 204, the image forming unit 202 forms a print image using the first printing device 115 on the roll paper 111 transported from the paper feeder 104 via the second printing device 116 based on a job. Job data may be received from an external device via the communication unit 203. The control unit 204 also controls the insertion of multiple detection marks of different colors in the margins of the roll paper 111, aligned with the beginning of each page of the job. Under the control of the control unit 204, the image forming unit 202 forms multiple detection marks of different colors on the roll paper 111 transported from the paper feeder 104 using the second printing device 116.

[0020] The communication unit 203 is configured with a communication control card such as a LAN (Local Area Network) card. The control unit 204 transmits and receives various data to and from an external device (e.g., a personal computer) connected to a communication network such as a LAN or a WAN (Wide Area Network) via the communication unit 203. The external device creates job data in response to a user's instruction. The external device transmits the created job data and setting information such as print settings for the job and settings for the number of rolls to be delivered to the image forming apparatus 100 via the communication network.

[0021] The control unit 204 is configured with a CPU (Central Processing Unit), RAM (Random Access Memory), etc. The control unit 204 controls the overall operation of the image forming apparatus 100. The CPU of the control unit 204 reads out various programs such as system programs and processing programs stored in the storage unit 205, loads them into the RAM, and executes various processes in accordance with the loaded programs. The control unit 204 can execute jobs in accordance with user instructions.

[0022] The storage unit 205 is configured by a non-volatile semiconductor memory (so-called flash memory), an HDD (Hard Disk Drive), etc. The storage unit 205 stores various programs, including system programs and processing programs, executed by the control unit 204, and various data required for executing these programs.

[0023] The operation display unit 206 is configured, for example, by a liquid crystal display (LCD) with a touch panel, and includes a display unit 206a and an operation unit 206b. The display unit 206a displays various information on the display screen in accordance with a display control signal input from the control unit 204. The operation unit 206b includes various operation keys such as a numeric keypad and a start key, and receives various input operations from the user and outputs operation signals to the control unit 204.

[0024] The operation display unit 206 is used to set a job, for example, when executing the job. The control unit 204 displays a UI on the display unit 206a for selecting items such as the type of paper to be used, print speed, number of prints, number of copies, print length, print weight, and print diameter, and sets each of the above items in accordance with input operations received by the operation unit 206.

[0025] The sensor connection I / F 207 is an interface for connecting to the sensor 120. The sensor 120 continuously reads and measures the luminance on the roll paper 111 along the transport direction before forming a print image in the first printing device 115. The control unit 204 acquires the luminance measurements taken by the sensor 120 in chronological order via the sensor connection I / F 207 and stores them in the memory unit 205. As a result, the memory unit 205 stores the measurement results of the luminance on the roll paper 111 versus the transport distance. Note that while the sensor 120 is used in this embodiment, a scanner device may also be used; this is not limiting. If a scanner device is used, the memory unit 205 stores the measurement results obtained from the scanned image data.

[0026] 2(b) shows the functional configuration of the image forming apparatus 100. The CPU of the control unit 204 reads out a program stored in the storage unit 205, expands it into RAM, and executes it, thereby realizing the functions of a detection unit 210, a determination unit 211, and a selection unit 212.

[0027] The detection unit 210 reads from the memory unit 205 the measurement results of the brightness on the roll paper 111 relative to the transport distance, and detects the detection mark based on the position where a change from the brightness of the paper base is observed. In this embodiment, multiple detection marks of different colors are formed on the roll paper 111, so multiple detection marks of different colors are detected. The determination unit 211 determines whether a plurality of detection marks detected by the detection unit 210 are valid detection marks or invalid detection marks. For example, a detection mark that satisfies the condition for erroneous detection is determined to be an invalid detection mark.

[0028] The selection unit 212 selects a detection mark to be used to identify the printing position of the print image from among the multiple detection marks detected by the detection unit 210, excluding those determined to be invalid by the determination unit 211. In this embodiment, the selection unit 212 selects the detection mark with the largest difference (brightness difference) between the brightness of the paper background and the brightness of the detection mark. The brightness of the paper background is an example of the brightness of the recording medium itself. The control unit 204 sets the selected detection mark as the detection mark to be used to identify the printing position, and controls the image forming unit 202.

[0029] FIG. 3 shows the mark selection process for selecting a detection mark using the measurement results of the brightness on the roll paper 111 relative to the transport distance. The control unit 204 sets the selected detection mark to identify the top position of the page and controls the printing position of the image printed by the first printing device 115. Below, each step (process) is denoted by an S before its reference number. The processing of this flowchart is realized by the CPU of the control unit 204 reading various programs stored in the storage unit 205, expanding them into RAM, and executing them. In this embodiment, roll paper 111 is used as the recording medium, so the medium to be measured is set in advance at the position of the sensor 120. However, this is not limited to roll paper 111, and the process can also be applied to cut sheets, which are transported one sheet at a time or manually inserted.

[0030] 4 shows an example of a detection mark. In this embodiment, a detection mark is inserted to identify the top position of a page, but the use case for inserting a detection mark is not limited to this and can be applied to various cases where the position of a print image on a recording medium, such as the print start position, the image analysis position, etc., is detected.

[0031] Area 400 in Figure 4(a) represents one page of the roll paper 111, including the area where the print image is printed (image area) and the margins on both sides of the image area. Three detection marks of different colors (white, black, and monochrome) are printed in the margins along the transport direction in the order of white, black, and monochrome. The monochrome color is, for example, one of the colors YMC. Because the distance from the start of the image area to each detection mark is fixed, it is possible to identify the start of the page using the selected detection mark and the transport distance.

[0032] In the example of Figure 4(a), a white detection mark 401 is printed to align with the leading position of the image area. A black detection mark 402 is printed a predetermined distance in the transport direction from the white detection mark 401. A single color detection mark 403 is printed a predetermined distance in the transport direction from the black detection mark 402. The color combination of the detection marks is not limited to this embodiment, and the colors may be changed or the number of colors may be increased or decreased depending on the characteristics of the paper, etc.

[0033] In this embodiment, the size of the detection marks 401, 402, and 403 is 3 mm in height and 3 mm in width, but they may be larger or smaller. Also, the luminance of the detection marks 401, 402, and 403 is measured in order by one sensor 120, but the detection marks 401, 402, and 403 may be arranged in a direction intersecting the transport direction, and the luminance of each may be measured simultaneously by the sensor 120.

[0034] The flowchart in FIG. 3 will be described. This flowchart begins when a job is executed in response to an instruction from the operation display unit 206. When the job is executed, transportation of the pre-set roll paper 111 begins, and multiple detection marks of different colors are printed in the margins of the roll paper 111, aligned with the start position of each page of the job. The sensor 120 measures the brightness of the roll paper 111 on which the detection marks are printed, and the memory unit 205 stores the measurement results of the brightness on the roll paper 111 versus the transport distance.

[0035] First, in S301, the detection unit 210 reads from the storage unit 205 the measurement results of the luminance on the roll paper 111 relative to the transport distance by the sensor 120, and obtains the luminance of the paper background. Next, in S302, the detection unit 210 detects a plurality of detection marks based on the measurement results read out in S301, at positions where a change from the luminance of the paper background is observed.

[0036] Detection of detection marks will be explained using Figure 5. In the graph of Figure 5(a), the horizontal axis represents the conveyance distance (position in the conveyance direction) and the vertical axis represents the brightness measured by the sensor 120. The brightness ranges, for example, from 0 to 255. Lower brightness indicates a darker color, and higher brightness indicates a lighter color. A broken line 420 represents brightness relative to the conveyance distance. Brightness 421 represents the brightness of the paper substrate. The detection unit 210 detects the detection mark 410 by using leading edge 425, which is the position on broken line 420 where a change from the brightness 421 of the paper substrate is observed. Because multiple detection marks (here, three detection marks 401, 402, and 403 in monochrome, white, black, and color) are formed on the roll paper 111, the detection unit 210 detects multiple detection marks.

[0037] In S303, the detection unit 210 repeatedly executes the process of S304, which will be described next, the number of times corresponding to the number of detection marks detected in S302. In S304, the detection unit 210 targets the first detected detection mark and calculates the luminance difference between the luminance of the target detection mark and the luminance of the paper background acquired in S301. Specifically, the detection unit 210 calculates the difference between luminance 422 of detection mark 410 and luminance 421 of the paper background as luminance difference 423. Next, the detection unit 210 targets the second and third detected detection marks in turn, and once it has calculated the luminance differences for all of the detection marks detected in S302, it proceeds to S305.

[0038] In this embodiment, three detection marks 401, 402, and 403 in monochrome (black and white, black and color) are printed, but it is possible that more than three detection marks may be detected due to erroneous detection or other reasons. In such cases, an error may occur in the correspondence between the brightness difference calculated in S304 and the detection marks 401, 402, and 403. Furthermore, depending on the material and background color of the roll paper 111, the three detection marks 401, 402, and 403 in monochrome (black and white, black and color) may not be appropriate for use in identifying the image position.

[0039] Therefore, in S305, the determination unit 211 performs a mark determination process to determine whether the multiple detection marks detected in S302 are valid detection marks or invalid detection marks. Details of the process performed in this step will be described later with reference to FIGS. 6 to 8. The determination unit 211 identifies the three detection marks 401, 402, and 403 of monochrome white, black, and color by excluding those determined to be invalid detection marks in S305 from the multiple detection marks detected in S302. Furthermore, if some of the three detection marks 401, 402, and 403 of monochrome white, black, and color are determined to be invalid detection marks in S305, only the detection marks excluding those some are subject to the processes from S306 onwards.

[0040] In S306, the selection unit 212 compares the luminance differences of the three detection marks 401, 402, and 403: white, black, and monochrome. In the subsequent steps S307 to S311, the selection unit 212 performs processing to select the detection mark with the largest luminance difference. For example, if the luminance of the paper background is 100 and the luminance of the white detection mark 401 is 100, the luminance difference is 0. Also, if the luminance of the paper background is 100 and the luminance of the black detection mark 402 is 70, the luminance difference is 30. Also, if the luminance of the paper background is 100 and the luminance of the monochrome detection mark 403 is 90, the luminance difference is 10.

[0041] In S307, if the selection unit 212 determines that the white detection mark 401 has the largest luminance difference, the process proceeds to S308, and if not, the process proceeds to S309. In S308, the selection unit 212 sets the white detection mark 401 as the detection mark used to identify the top position of the page. In S309, if the selection unit 212 determines that the luminance difference of the black detection mark 402 is the largest, the process proceeds to S310; otherwise, the selection unit 212 determines that the luminance difference of the monochrome detection mark 403 is the largest and proceeds to S311.

[0042] In S310, the selection unit 212 sets the black detection mark 402 as the detection mark used to identify the top position of the page. In S311, the selection unit 212 sets the monochrome detection mark 403 as the detection mark used to identify the top position of the page. Here, since the luminance difference of the black detection mark 402 calculated in S304 is the largest, the black detection mark 402 is set as the detection mark used to identify the top position of the page. In S312, the control unit 204 controls the image forming unit 202 to identify the top position of the page using the detection mark of the color set in S308, S310, or S311, and prints the print image. After that, the series of processes in the flowchart ends.

[0043] Next, the mark determination process for determining whether the detection mark is valid or invalid, which is executed in S305 before the process for comparing the brightness difference, will be described with reference to the flowcharts of Figures 6 to 8. Note that, among the processes shown in the flowcharts of Figures 6 to 8, any one of the processes may be selectively executed depending on the usage environment of the image forming system 200, or all of the processes may be executed.

[0044] The mark determination process shown in Fig. 6 is a process for determining whether a detection mark is valid or invalid based on the detection distance, which is the distance from the leading edge to the trailing edge of the detected detection mark. In the example of Fig. 5(a), the detection distance of the detection mark 410 is the distance from the leading edge 425, which is the position on the broken line 420 where a change from the luminance 421 of the paper background is observed, to the trailing edge 426, which is the position where the luminance 421 of the paper background is observed again.

[0045] FIG. 4(b) shows a state in which a stain 411 has adhered next to the monochrome detection mark 403 in FIG. 4(a). The stain 411 is an example of an object that may result in erroneous detection of a detection mark. The stain 411 is expected to be, but is not limited to, mixed dust or scratches on the roll paper. The stain 411 is expected to be smaller than the size of the detection mark. Therefore, in the mark determination process shown in FIG. 6, of the multiple detection marks detected by the detection unit 210, those smaller than the size of the detection mark, such as the stain 411, are excluded from the detection marks to be selected by the selection unit 212.

[0046] FIG. 5(b) shows the measurement results of an object that is erroneously detected. In the graph of FIG. 5(b), the horizontal axis represents the transport distance, and the vertical axis represents the luminance measured by the sensor 120. Luminance 445 represents the luminance of the paper substrate. FIG. 5(a) shows a case where the luminance of the paper substrate is higher than the luminance of the detection mark, while FIG. 5(b) shows a case where the luminance of the paper substrate is lower than the luminance of the detection mark. A broken line 440 represents luminance versus transport distance. Here, a change from the luminance 445 of the paper substrate is observed at the position of stain 432 on broken line 440, so stain 432 is detected by the detection unit 210, but the detection distance of stain 432 is shorter than the detection distance of detection mark 430. Therefore, in the mark determination process shown in FIG. 6, a mark such as stain 432 that is shorter than the detection distance of detection mark 430 is determined to be an invalid detection mark.

[0047] In S601, the determination unit 211 repeatedly executes the processes of S602 to S605 for the number of detection marks detected in S302. In the example of Fig. 4(b), the three detection marks 401, 402, and 403 in monochrome (white, black, and color) and the stain 411 are the targets of the processes of S602 to S605. In S602, the determination unit 211 targets the first detected detection mark and calculates the detection distance of the target detection mark.

[0048] In S603, the determination unit 211 determines whether the detection distance calculated in S602 is equal to or greater than a threshold value (for example, 2 mm). If it is equal to or greater than the threshold value, the process proceeds to S604, and if it is less than the threshold value, the process proceeds to S605. Here, the threshold value for the detection distance is set to 2 mm, but it can be set appropriately depending on the measurement accuracy of the sensor 120, the size of the margin, etc. In S604, the determination unit 211 determines that the target detection mark is a valid mark. In S605, the determination unit 211 determines that the target detection mark is an invalid mark.

[0049] Next, the determination unit 211 sequentially targets the second, third, etc. detected detection marks and determines whether all of the detection marks are valid or invalid based on the detection distance. After that, the processing of this flowchart ends. For example, the three detection marks 401, 402, and 403, which are white, black, and color, have a width of 3 mm in the transport direction and are therefore determined to be valid in S604, but if the width of the stain 411 in the transport direction is 1 mm, it will be determined to be invalid in S605.

[0050] According to this flowchart, by determining that the stain 411 shown in FIG. 4(b) among the multiple detection marks detected in S302 is invalid, the stain 411 can be excluded from the processing from S305 onward in FIG. 3.

[0051] The mark determination process shown in FIG. 7 is a process for determining whether a detection mark is valid or invalid based on the maximum brightness value of the detected detection mark. FIG. 4(c) shows a state in which external light 412 is reflected next to the monochrome detection mark 403 in FIG. 4(a). The external light 412 is an example of a detection mark that may be erroneously detected. The external light 412 may be light from outside the image forming system 200 or another light source, but is not limited to these. The luminance of the external light 412 is expected to be extremely high. As shown in FIG. 5(b), a change from the luminance 445 of the paper substrate is observed at the position of the external light 431 on the broken line 440, and is detected by the detection unit 210. However, the maximum luminance of the external light 431 is higher than the predetermined upper limit 433. Therefore, in the mark determination process shown in FIG. 7, a luminance higher than the upper limit 433, such as the external light 431, is determined to be an invalid detection mark.

[0052] In S701, the determination unit 211 repeatedly executes the processes of S702 to S704 for the number of detection marks detected in S302. In the example of Fig. 4(c), the three detection marks 401, 402, and 403 of monochrome white, black, and color, and the external light 412 are the targets of the processes of S702 to S704. In S702, the determination unit 211 targets the first detected detection mark and acquires the maximum brightness value of the target detection mark. Then, the determination unit 211 determines whether the acquired maximum brightness value is less than an upper limit value (e.g., 200). If it is less than the upper limit value, the process proceeds to S703, and if it is equal to or greater than the upper limit value, the process proceeds to S704.

[0053] In S703, the determination unit 211 determines that the target detection mark is a valid mark. In S704, the determination unit 211 determines that the target detection mark is an invalid mark. Next, the determination unit 211 sequentially targets the second, third, etc. detected detection marks, and determines whether all of the detection marks are valid or invalid based on the maximum brightness value. After that, the processing of this flowchart ends.

[0054] According to this flowchart, by determining that the external light 412 shown in FIG. 4(c) is invalid among the multiple detection marks detected in S302, it is possible to exclude it from the processing targets of S305 and thereafter in FIG. 3. Note that the external light 412 is expected to be larger than the size of the detection mark. Therefore, detection marks larger than the size of the detection mark may be excluded from the detection marks to be selected by the selection unit 212.

[0055] The mark determination process shown in FIG. 8 determines whether a detection mark is valid or invalid based on whether the brightness of the detected detection mark is within a predetermined range. In addition to fine paper, special materials such as metallic paper and holographic paper may be used as the roll paper 111, and the degree of light reflection varies depending on the paper type. Therefore, in some cases, the mark can be detected more accurately by changing the brightness range (upper and lower limits) within which the mark can be properly detected based on the brightness measured by the sensor 120, depending on the paper type. In this embodiment, an example is described in which upper and lower limits are registered for two types of paper: fine paper and metallic paper. In this embodiment, the upper limit and lower limit for fine paper are registered in advance as 150 and 50, respectively, and the upper limit and lower limit for metallic paper are registered in advance as 200 and 100, respectively. Note that the paper types are not limited to fine paper and metallic paper.

[0056] In S801, the determination unit 211 acquires the type of paper set in the image forming system 200, and acquires the upper and lower limit values ​​of brightness that are associated with the acquired type of paper. The type of paper may be acquired by identifying it from the brightness of the paper background, or may be acquired by a user's input operation via a UI displayed on the operation display unit 206. Registration information on the upper and lower limit values ​​of brightness for each type of paper is stored in the storage unit 205 or the like.

[0057] Next, in S802, the determination unit 211 repeatedly executes the processes of S803 to S804 the number of times equal to the number of detection marks detected in S302. In S802, the determination unit 211 targets the first detected detection mark and acquires the brightness of the target detection mark. In S803, the determination unit 211 determines whether the luminance acquired in S802 is within the range between the upper limit and lower limit values ​​acquired in S801. If the luminance is within the range between the upper limit and lower limit values, the process proceeds to S804, and if the luminance is outside the range between the upper limit and lower limit values, the process proceeds to S805.

[0058] For example, if the paper loaded in the image forming system 200 is high-quality paper and the brightness of the white detection mark 401 is 100, it is determined to be valid in S804. If the paper loaded thereafter is switched to metallic paper, and the brightness of the white detection mark 401 is 100, it is determined to be valid in S804, but if the brightness of the black detection mark 402 is 70, it is determined to be invalid in S805.

[0059] According to this flowchart, from among the multiple detection marks detected in S302, marks of a color that is not suitable for use as a detection mark in relation to the type of paper can be excluded from processing from S305 onwards in Figure 3.

[0060] According to the present embodiment, multiple marks of different colors are printed on the recording medium in advance, and the mark to be used for position detection can be selected from the multiple marks based on the brightness of each of the multiple marks. This makes it possible to avoid situations where the mark cannot be detected because the difference between the color of the background of the paper is small, and to detect the mark with high accuracy.

[0061] The above-described embodiments may also be realized by executing the following process. That is, computer-readable software (computer program) that realizes the functions of the above-described embodiments is supplied to a system or device via a network or various storage media. The computer (or CPU, MPU, etc.) of the system or device reads and executes the program.

[0062] The disclosure of each of the above-described embodiments includes the following configurations, methods, and programs. (Configuration 1) a detection means for detecting a plurality of marks of different colors formed on the recording medium based on a measurement result obtained by reading the recording medium being conveyed; a selection means for selecting a mark to be used to identify the position of an image to be printed on a recording medium based on the measurement values ​​of each of the plurality of marks; An information processing device comprising: (Configuration 2) 2. The information processing device according to configuration 1, wherein the measurement result is a luminance measurement value. (Configuration 3) 3. The information processing device according to configuration 1 or 2, wherein the selection means selects the mark based on a luminance difference representing a difference between the luminance of each of the plurality of marks and the luminance of the recording medium itself. (Configuration 4) 4. The information processing device according to configuration 3, wherein the selection means selects the mark having the largest luminance difference from among the plurality of marks. (Configuration 5) 5. The information processing device according to any one of configurations 1 to 4, wherein the marks are printed with inks of different colors before the image is printed on the recording medium. (Configuration 6) 6. The information processing device according to configuration 5, wherein the plurality of inks includes a white ink. (Configuration 7) The information processing device according to any one of configurations 1 to 6, wherein the selection means obtains the distance in the transport direction of each area of ​​the plurality of marks from the measurement results, and excludes from the selection targets any marks of which the distance is less than a predetermined threshold value or the distance is greater than a predetermined threshold value. (Configuration 8) The information processing device according to any one of configurations 1 to 7, wherein the selection means obtains the maximum brightness value of each of the plurality of marks from the measurement results, and excludes from the selection targets any mark among the plurality of marks whose maximum brightness value is equal to or greater than a predetermined threshold value. (Configuration 9) The recording medium further includes an acquisition unit for acquiring a luminance range associated with a paper type of the recording medium, 9. The information processing device according to any one of configurations 1 to 8, wherein the selection means excludes from selection targets any of the marks whose brightness is outside the brightness range. (Configuration 10) 10. The information processing device according to any one of configurations 1 to 9, wherein the recording medium is continuous paper. (Configuration 11) The information processing device according to any one of configurations 1 to 10, further comprising a printing means for printing the marks with inks of different colors in positions that do not overlap with the image before the image is printed on the recording medium. (method) a detection step of detecting a plurality of marks of different colors formed on the recording medium based on a measurement result obtained by reading the conveyed recording medium; a selecting step of selecting a mark to be used to identify the location of an image to be printed on a recording medium based on the measurement values ​​of each of the plurality of marks; An information processing method comprising: (program) The computer of the information processing device, a detection means for detecting a plurality of marks of different colors formed on the recording medium based on a measurement result obtained by reading the recording medium being conveyed; a selection means for selecting, based on the measurement values ​​of each of the plurality of marks, a mark to be used to identify the position of an image to be printed on a recording medium; A program characterized by functioning as [Explanation of symbols]

[0063] 100: Image forming apparatus, 104: Paper feeder, 105: Paper discharger, 115: First printing apparatus, 116: Second printing apparatus, 120: Sensor, 200: Image forming system

Claims

1. a detection means for detecting a plurality of marks of different colors formed on the recording medium based on a measurement result obtained by reading the recording medium being conveyed; a selection means for selecting a mark to be used to identify the position of an image to be printed on a recording medium based on the measurement values ​​of each of the plurality of marks; An information processing device comprising:

2. 2. The information processing apparatus according to claim 1, wherein the measurement result is a measured value of luminance.

3. 2. The information processing apparatus according to claim 1, wherein said selecting means selects said marks based on a luminance difference representing a difference between the luminance of each of said plurality of marks and the luminance of the recording medium itself.

4. 4. The information processing apparatus according to claim 3, wherein the selection means selects the mark having the largest luminance difference from among the plurality of marks.

5. 2. The information processing apparatus according to claim 1, wherein the plurality of marks are printed with a plurality of inks of different colors before the image is printed on the recording medium.

6. 6. The information processing apparatus according to claim 5, wherein the plurality of inks includes a white ink.

7. The information processing device according to claim 1, characterized in that the selection means obtains the distance in the transport direction of each area of ​​the plurality of marks from the measurement results, and excludes from the selection targets any marks of the plurality of marks whose distance is less than a predetermined threshold value or whose distance is greater than a predetermined threshold value.

8. 2. The information processing device according to claim 1, wherein the selection means obtains the maximum brightness value of each of the plurality of marks from the measurement results, and excludes from the selection targets any mark among the plurality of marks whose maximum brightness value is equal to or greater than a predetermined threshold value.

9. The recording medium further includes an acquisition unit for acquiring a luminance range associated with a paper type of the recording medium, 2. The information processing apparatus according to claim 1, wherein the selection means excludes from the selection targets any of the plurality of marks whose brightness is not included in the brightness range.

10. 2. The information processing apparatus according to claim 1, wherein the recording medium is continuous paper.

11. 2. The information processing apparatus according to claim 1, further comprising a printing means for printing the marks with inks of different colors at positions that do not overlap the image before the image is printed on the recording medium.

12. a detection step of detecting a plurality of marks of different colors formed on the recording medium based on a measurement result obtained by reading the conveyed recording medium; a selecting step of selecting a mark to be used to identify the location of an image to be printed on a recording medium based on the measurement values ​​of each of the plurality of marks; An information processing method comprising:

13. The computer of the information processing device, a detection means for detecting a plurality of marks of different colors formed on the recording medium based on a measurement result obtained by reading the recording medium being conveyed; a selection means for selecting, based on the measurement values ​​of each of the plurality of marks, a mark to be used to identify the position of an image to be printed on a recording medium; A program characterized by functioning as

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