Reading device, image forming system, and control program

Abstract

To accurately detect a sheet size or a sheet shape.SOLUTION: A reading device comprises: a reading unit 50 including a reading sensor 51 that optically reads a sheet conveyed through a conveyance path 341; and a control unit that controls the reading unit 50. The reading unit 50 comprises a background unit 56 that is arranged opposite to the reading sensor 51 with the conveyance path 341 therebetween, the background unit 56 having background surfaces 561, 562 to be the background of the sheet when it is read. The control unit switches between the background surfaces 561, 562 of the background unit 56 on the basis of attribute information of the sheet to be conveyed.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a reading device, an image forming system, and a control program. [Background technology]

[0002] There is a technology in which an image forming device detects the size of a sheet of paper and corrects an image according to the detected size (for example, Patent Document 1). In the image forming device disclosed in Patent Document 1, the size measuring unit is disposed sufficiently upstream of the image forming unit, so that the image position correction set based on the measurement result of the size measuring unit is reflected in the detected sheet of paper.

[0003] Furthermore, in Patent Document 1, a contact image sensor (CIS) that measures the paper width as a size measurement unit detects the positions of the side edges of the paper (the positions of the right edge and the left edge in the conveying direction) to measure the paper width (paragraph 0013). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-238544 A Summary of the Invention [Problem to be solved by the invention]

[0005] In image forming devices, various types of paper are used, for example, dark colored paper other than white paper may be used. In the above-mentioned image forming device, the positions of both side edges of the paper are detected by the CIS, but with colored paper, there is a risk that the edges cannot be detected accurately because sufficient contrast cannot be obtained at the edge positions.

[0006] The present invention has been made in consideration of the above circumstances, and has an object to provide a reading device that can detect the paper size or shape with high accuracy. [Means for solving the problem]

[0007] The above object of the present invention can be achieved by the following means.

[0008] (1) a conveying section that conveys paper in a conveying path; a reading unit including a reading sensor that optically reads the paper conveyed through the conveying path; A control unit that controls the reading unit, the reading unit includes a background unit disposed opposite the reading sensor across the transport path, the background unit having a background surface that becomes a background of the paper when reading; The control unit switches the background surface of the background unit based on attribute information of the paper being transported.

[0009] (2) the background portion has a plurality of background surfaces having different colors or brightnesses; the attribute information of the paper is information on the color of the paper, The control unit switches the background surface based on information about a color of the paper.

[0010] (3) The reading device according to (1) above, wherein the reading unit reads an edge of a paper sheet transported over the background surface.

[0011] (4) The background portion has a first background surface and a second background surface having a different brightness from that of the first background surface, The control unit switches to a background surface having a greater brightness difference with respect to the color of the paper being conveyed.

[0012] (5) The reading unit includes a first reading sensor and a second reading sensor; a first background portion disposed opposite the first reading sensor and a second background portion disposed opposite the second reading sensor, The reading device according to (1) above, wherein the control unit switches the background surface of the first background portion and the background surface of the second background portion based on attribute information of the paper.

[0013] (6) each of the first and second background portions has a plurality of background planes having different colors or brightnesses; The paper attribute information includes information on the size of the paper, The reading device according to (5) above, wherein the control unit switches the background surface of the first background portion and the background surface of the second background portion based on a size of a paper sheet.

[0014] (7) The reading device described in (6) above, wherein the first reading sensor and the second reading sensor are arranged adjacent to each other in the paper transport direction and are arranged so that at least a portion of the reading area is different in the width direction perpendicular to the transport direction.

[0015] (8) The first reading sensor and the second reading sensor have reading areas that overlap in the width direction, The reading device described in (7) above, wherein the control unit controls a combination such that the background surface of the first background part and the background surface of the second background part have a brightness difference of a predetermined value or more when the size of the paper in the width direction is equal to or smaller than a predetermined value.

[0016] (9) a paper feed unit that feeds paper; A reading device according to any one of (1) to (8) above, an image forming unit that forms an image on the paper conveyed from the reading device; a correction value calculation unit that calculates a paper position correction value based on read data obtained by reading the paper by the reading device; and a print control unit that adjusts an image formation position on at least one of a first side and a second side of the read paper based on the paper position correction value calculated by the correction value calculation unit.

[0017] (10) a paper feed unit that feeds paper; a conveying section that conveys paper along a conveying path; a reading unit including a reading sensor that optically reads the paper conveyed through the conveying path; an image forming unit that is located downstream of the reading unit in the conveying path and that forms an image on the conveyed paper; A control unit that controls the reading unit, the reading unit includes a background unit disposed opposite the reading sensor across the transport path, the background unit having a background surface that becomes a background of the paper when reading; The control unit switches the background surface of the background unit based on attribute information of the paper being transported.

[0018] (11) a paper feed unit that feeds paper; a conveying section that conveys paper along a conveying path; a reading unit including a reading sensor that optically reads the paper conveyed along the conveying path; an image forming unit that is disposed in a conveyance path downstream of the reading unit and that forms an image on conveyed paper, the reading unit includes a background unit disposed opposite the reading sensor across the transport path, the background unit having a background surface that becomes a background of the paper when reading; A control program that executes a process of switching the background surface of the background portion based on attribute information of the paper being conveyed. Effect of the Invention

[0019] In the reading device according to the present invention, the reading unit includes a reading sensor and a background unit disposed opposite the reading sensor across the transport path, the background unit having a background surface that becomes the background of the paper when it is read, and the background surface of the background unit is switched based on attribute information of the paper being transported. In this way, the paper size or shape can be detected with high accuracy. [Brief description of the drawings]

[0020] [Figure 1] 1 is a diagram showing a schematic configuration of an image forming apparatus including a reading device according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a block diagram showing a hardware configuration of the image forming system. [Diagram 3] 2 is a schematic diagram showing a main configuration of a reading unit in the first embodiment. FIG. [Figure 4] FIG. 2 is a schematic diagram showing a main configuration of a reading unit. [Diagram 5] 13 is a table for explaining the use conditions of each surface of the background portion. [Figure 6] 13 is a table for explaining the use conditions of each surface of the background portion. [Figure 7] 6 is a flowchart showing a background plane switching process and a printing process in the first embodiment. [Figure 8] 8 is a subroutine flowchart showing the process of step S12 in FIG. 7. [Figure 9] 2 is an example of a print job. [Figure 10] FIG. 11 is a schematic diagram showing a main configuration of a reading unit in a second embodiment. [Figure 11] 13 is a table for explaining the use conditions of each surface of the background portion. [Figure 12] 10 is a flowchart showing a background plane switching process and a printing process in the second embodiment. [Figure 13] 13 is a subroutine flowchart showing the process of step S32 in FIG. 12. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the attached drawings. However, the scope of the present invention is not limited to the disclosed embodiment. In the description of the drawings, the same elements are given the same reference numerals, and duplicated description will be omitted. Also, the dimensional ratios of the drawings are exaggerated for convenience of description, and may differ from the actual ratios. In the drawings, the up-down direction (vertical direction) is the Z direction, the front and back directions of the image forming system or the reading device are the Y direction, and the direction perpendicular to these Y and Z directions is the X direction. The X direction is also called the paper transport direction. The Y direction is also called the width direction. In this embodiment, the paper includes printing paper (hereinafter simply called paper) and various films.

[0022] Fig. 1 is a diagram showing a schematic configuration of an image forming system 1000 including a reading device 30 according to this embodiment. Fig. 2 is a block diagram showing a hardware configuration of the image forming system 1000. As shown in Fig. 1, the image forming system 1000 includes an image forming device 10, a paper feeder 20, a reading device 30, and a post-processing device 40, which are mechanically and electrically connected to each other.

[0023] (Image forming apparatus 10) The image forming apparatus 10 forms an image on a sheet 90 that is fed from a sheet feeding device 20 on the upstream side and sent via a reading device 30. The image forming apparatus 10 also forms an image on a sheet 90 that is fed from a sheet feeding section of the image forming apparatus 10 itself.

[0024] The image forming apparatus 10 includes a control unit 11, a storage unit 12, an image forming unit 13, a conveying unit 14, a paper feeding unit 15, an operation panel 18, a communication unit 19, etc. These are connected to each other via signal lines such as a bus for exchanging signals. Note that in Fig. 2, the signal lines connecting some of the components of the image forming apparatus 10, such as the storage unit 12 and the operation panel 18, are omitted (the connection to the control unit 31 of the reading device 30 described below, etc. is also omitted).

[0025] (Control unit 11) The control unit 11 is composed of a CPU, a ROM, a RAM, etc., and executes various processes by executing programs stored in the ROM or in a storage unit 12 described below, and controls each unit of the device and performs various arithmetic processes according to the programs. The control unit 11 functions as a print control unit 111, a reading device control unit 112, an other device control unit 113, and a correction value calculation unit 114. The functions of these sub-control units 111 to 114 will be described later.

[0026] (Storage unit 12) The storage unit 12 is an auxiliary storage unit such as a hard disk that stores various programs and various data in advance. The storage unit 12 also stores information on the paper stored in each paper feed tray (trays 155, 255, 256, etc., described below) in association with the paper feed tray. The paper information includes information on the paper brand, size (paper width, paper length), paper color, basis weight (basis weight), and paper type (gloss coated paper, matte coated paper, plain paper, fine paper, rough paper, etc.). The storage unit 12 may also store paper brands, a determination model (determination model algorithm) used to determine control parameters, and a paper profile.

[0027] (Image forming unit 13) The image forming unit 13 forms an image, for example, by an electrophotographic method. The image forming unit 13 includes writing units (laser exposure units) corresponding to the basic colors of Y (yellow), M (magenta), C (cyan), and K (black), a photosensitive drum, and a developing unit that contains a two-component developer consisting of toner and carrier of each color. The image forming unit 13 further includes an intermediate transfer belt, a secondary transfer unit, and a fixing unit. The toner images formed on the photosensitive drum by the developing units of each color are superimposed on the intermediate transfer belt, and are transferred to the paper 90 conveyed in the secondary transfer unit. The toner image on the paper 90 is fixed onto the paper 90 by being heated and pressed in the fixing unit downstream.

[0028] (Transport section 14, Paper feed section 15) The transport unit 14 includes transport paths 141, 142, etc. The paper feed unit 15 includes a plurality of paper feed trays 155. The transport path 141 includes a plurality of transport roller pairs provided along the transport path, and a drive motor (not shown) that drives these transport roller pairs. The paper feed unit 15 includes a feed roller that feeds the topmost sheet of paper 90 stacked and placed in the paper feed tray 155, and sends the sheets 90 in the paper feed tray one by one to the downstream transport path. A transport path 341 of the reading device 30 is connected to the upstream side of the transport path 141.

[0029] The conveying section 14 conveys the paper 90 fed from the paper feed tray 155 or the like. The paper 90 conveyed along the conveying path 141 has an image formed on it by the image forming section 13, and is then discharged onto the paper output tray 41 via the subsequent post-processing device 40. When performing double-sided printing in which an image is also formed on the back side (second side) of the paper 90, the paper 90 with an image formed on one side is conveyed to a conveying path 142 for double-sided image formation located at the bottom of the device main body. The paper 90 conveyed to this conveying path 142 is turned over on a switchback path, and then merges with the conveying path 141 for one side, where an image is again formed on the other side of the paper 90 by the image forming section 13.

[0030] (Operation panel 18, etc.) Operation panel 18 includes a touch panel, numeric keypad, start button, stop button, etc. Operation panel 18 displays the status of image forming apparatus 10 or image forming system 1000, and is used for inputting various settings and instructions from the user. The user can set the type of paper loaded in paper feed trays 155, 255, etc., and paper color information through the setting screen of operation panel 18 (see FIG. 6 described later). In addition, the user can set the following through the setting screen of operation panel 18 or the setting screen of a print setting application running on a PC (personal computer) communicatively connected to image forming system 1000 (hereinafter referred to as operation panel, etc.). (1) Paper size to be used as print settings, (2) Paper color information, and (3) Setting of paper image position correction, such as enable / disable, etc. In the following, the paper size and color information of the paper are also referred to as paper attribute information.

[0031] The communication unit 19 is an interface for communicating with a PC or other devices 20, 30, etc.

[0032] (Sub-control units 111 to 114) When a print job is input, the print control unit 111 executes the print job based on the print job setting information of the input print job. The print job is input based on instructions sent from the operation panel 18 or an external terminal such as a network-connected PC operated by a user.

[0033] The print control unit 111 controls the transport unit 14 (including drive motors for transport paths 141, 142, the fixing unit, etc.) and the paper feed unit 15 to control the feeding and transporting of the paper 90. The print control unit 111 also instructs the reading device control unit 112 to read the paper 90 before image formation (reading instruction) according to the print job settings (enablement of image position correction). The print control unit 111 also controls the image forming unit 13, controls the image formation timing according to the image formation conditions and the paper position based on the paper position correction value calculated by the correction value calculation unit 114 described later, and adjusts the vertical and horizontal magnification (hereinafter referred to as position correction control).

[0034] As described below, the position correction control is performed on at least either the first surface (front side) or the second surface (back side) depending on the placement position of at least the reading unit 50. The placement condition of the reading unit 50 varies depending on the conveying path length or conveying speed of the reading device 30 itself, or if another device is connected between the reading device 30 and the image forming apparatus 10. (1) Possible placement conditions for both the first and second sides For example, if the reading unit 50 is located sufficiently upstream of the image forming unit 13 (similar to, for example, JP 2014-238544 A) and the image correction timing is in time, the position correction control is performed for the paper 90 that has been read. Specifically, if the reading unit 50 is disposed in a positional relationship such that (b) comes after (a) below, position correction control is performed when forming an image on the first and / or second side of the paper 90 that has been read: (a) the timing at which preparation for image formation reflecting position correction control is completed from image data (hereinafter referred to as read data) obtained by reading the paper 90 by the reading unit 50 of the reading device 30, and (b) the timing at which image formation on the paper 90 begins. (2) Placement conditions possible only on the second side Furthermore, if the placement condition of the reading device 30 is such that the image correction timing is not possible, image formation is performed that reflects position correction control when forming an image on the second side (reverse side) of the read paper 90 during double-sided image formation in order to align the image registration on the front and back sides.

[0035] The reading device control unit 112 controls the reading device 30 in response to an execution instruction request (reading instruction) from the print control unit 111. In response to the execution instruction request, the reading device 30 executes measurement of paper characteristics using the reading unit 50 and various other sensors included in the reading device 30. Furthermore, when the reading device 30 reads a paper 90, the reading device control unit 112 acquires read data generated by the reading device 30. This read data is read data generated by one reading unit 50, or read data obtained by combining two pieces of data obtained by reading with two reading units 50 (see FIG. 10 described later).

[0036] The other device control unit 113 controls the sheet feeding device 20 and the post-processing device 40. Specifically, the other device control unit 113 communicates with the sheet feeding device 20 to transmit and receive information on the sheet feeding tray to be used, the timing of sheet transport, etc. Specifically, the other device control unit 113 transmits to the post-processing device 40 the timing of sheet transport, setting information for post-processing of the sheets to be transported, etc.

[0037] The correction value calculation unit 114 obtains read data obtained by reading the paper 90 before image formation from the reading device control unit 112, and detects the length and shape characteristics of each side (length and width) of the paper 90 by recognizing the ends (edges) of the paper 90 from the obtained read data (hereinafter, the detected characteristics are also simply referred to as "paper size"). The correction value calculation unit 114 calculates an image position correction value from the difference between the detected paper size and the paper size in the print settings. The calculated image position correction value is sent to the print control unit 111. As described above, the print control unit 11 performs position correction control to match the paper position according to this image position correction value.

[0038] (Paper feeder 20) 1 and 2, sheet feeding device 20 includes a conveying unit 24 and a sheet feeding unit 25. In addition to conveying unit 24 and sheet feeding unit 25, sheet feeding device 20 also includes a control unit, a storage unit, and a communication unit (none of which are shown), which are connected to each other via signal lines such as a bus for exchanging signals.

[0039] The paper feed unit 25 includes a plurality of paper feed trays 255 and a manual feed tray 256. The paper feed trays 255 are automatically numbered from tray 1 to tray n based on a predetermined rule. The transport unit 24 and the paper feed unit 25 have the same functions as the transport unit 14 and the paper feed unit 15, and feed paper 90 placed on the paper feed tray 255 or the like one sheet at a time and transport it to the transport path 241. The transport path 241 is connected to the subsequent transport path 341. The paper 90 fed from the paper feed tray 245 or the like and transported on the transport path 241 is transported to the downstream reading device 30, where the paper characteristics such as the paper size are measured, and an image is formed on the paper by the image forming device 10 further downstream.

[0040] (Post-processing device 40) The post-processing device 40 performs post-processing on the paper 90 sent from the image forming device 10 and discharges the paper 90 according to the settings of the print job. The post-processing device 40 includes paper output trays 41 and 42, a post-processing unit 43, and a conveying path 441. The post-processing device 40 also includes a control unit, a storage unit, a conveying unit, and a communication unit (none of which are shown), which are connected to each other via signal lines such as a bus for exchanging signals. The paper output trays 41 and 42 are selected according to the settings of the print job. The conveying path 441 is connected to the conveying path 141 on the upstream side. The post-processing unit 43 performs at least one of post-processing, including stapling, punching, cutting, folding, and bookbinding, on the paper 90 on which an image has been formed.

[0041] (Reader 30) Next, the reading device 30 will be described. As shown in Fig. 2, the reading device 30 includes a control unit 31, a storage unit 32, a conveying unit 34, a communication unit 39, a reading unit 50, etc. The control unit 31, the storage unit 32, the conveying unit 34, and the communication unit 39 each have the same hardware configuration as the control unit 11, the storage unit 12, the conveying unit 14, and the communication unit 19 of the image forming apparatus 10 described above, and therefore the description thereof will be omitted.

[0042] (Reading unit 50) The outline of the reading unit 50 will be described below with reference to FIG. 3 to FIG. 6. FIG. 3 and FIG. 4 are schematic diagrams showing the main configuration of the reading unit 50. FIG. 3(a) is a top view, and FIG. 3(b) is a side view. The reading unit 50 includes a reading sensor 51, a background unit 56, and a switching mechanism 57. The reading sensor 51 is a one-dimensional line sensor having a plurality of photoelectric conversion elements arranged in the Y direction, and reads a one-dimensional image. The reading sensor 51 also has optical elements such as light-emitting elements and lens arrays arranged along the row of the photoelectric conversion elements. During reading, the light-emitting elements irradiate uniform light in the extension direction of the row toward the paper 90 on the conveying path 341. The reading unit 50 reads the paper 90, and read data corresponding to one sheet of paper is generated.

[0043] The background portion 56 has a shape of a polygonal prism whose cross section extends in the Y direction. In the example shown in FIG. 4 etc., the background portion 56 has a shape of a quadrangular prism having four faces 561 to 564. The switching mechanism 57 is composed of a driving source and a rotation mechanism such as gears, and switches the background face facing the reading sensor 51 by controlling the rotation position of the background portion 56. For example, the switching mechanism 57 has a servo motor or a stepping motor, and rotates the background portion 56 around the rotation axis by a predetermined angle (an integer multiple of 90 degrees) and stops it at that position.

[0044] 3(b) and 4, the background portion 56 is disposed facing the reading sensor 51 across the transport path 341. The background portion 56 is disposed in a cut-out portion of a lower guide plate that constitutes the transport path 341. The background portion 56 has four surfaces 561 to 564, and the surface that faces the reading sensor 51 is switched by a switching mechanism 57.

[0045] The configuration of the background section 56 is not limited to the example shown in FIG. 4 and may be other configurations. For example, four faces are arranged in the X direction on a plate-like background section 56. Then, the background section 56 is slid a predetermined amount back and forth in the X direction by the switching mechanism 57 to switch the face facing the reading sensor 51. As another example, the background section 56 may be configured as a device that can electrically switch the density of the display surface, such as electronic paper. In this case, the density (brightness) of the face facing the reading sensor 51 is switched by electrical control.

[0046] 3(a), the reading area of ​​the reading sensor 51 in the Y direction ranges from y0 to y100, which is wider than the maximum paper width of the paper 90 that can be transported in the image forming system 1000. In addition, in the Y direction, the center c1 of the transport of the paper 90 and the center c1 of the reading area of ​​the reading sensor 51 are aligned.

[0047] (Background surface 1, 2, paper passing surface, etc.) 5 and 6 are tables for explaining the usage conditions of surfaces 561 to 564 of background portion 56. These tables are stored in advance in storage unit 12 or storage unit 32. Background surfaces 1 and 2 (surfaces 561 and 562) are surfaces that are used when the reading setting in reading unit 50 is valid.

[0048] Surface 561 is black or a color whose brightness is equal to or less than a predetermined value (for example, L in the CIELAB color space). * 20 or less). Surface 561 is a first background surface (hereinafter also referred to as "background surface 1") that becomes the background of paper 90 when read by reading sensor 51. As shown in Figs. 5 and 6, background surface 1 is used when the color information of paper 90 to be read is included in the first group and is a light color with a brightness difference from surface 561 that is greater than or equal to a predetermined value.

[0049] Surface 562 is white or a color whose brightness is equal to or greater than a predetermined value (for example, L in the CIELAB color space). *Surface 562 is a second background surface (hereinafter also referred to as "background surface 2") that becomes the background of paper 90 when read by reading sensor 51. As shown in Figs. 5 and 6, background surface 2 is used when the color information of paper 90 to be read is included in the second group and is a dark color with a brightness difference from surface 562 that is greater than or equal to a predetermined value.

[0050] The surface 563 is a calibration surface used for calibration of the reading sensor 51, which is performed periodically at a predetermined timing of the reading sensor 51. For example, the surface 563 is configured to have a white color within a specified range, and is used for adjusting the white balance and white level.

[0051] Surface 564 is used when reading is not performed (reading setting is invalid) and functions as a paper passing surface that covers the cutout portion of the lower guide plate of conveying path 341 when paper is passed.

[0052] (Background surface switching and printing) Next, the background switching process and the printing process executed by the image forming system 1000 according to the first embodiment will be described with reference to FIGS.

[0053] Fig. 7 is a flowchart showing the background surface switching process executed by the reading device 30 and the printing process executed by the image forming system 1000. Fig. 8 is a subroutine flowchart showing the process of step S12 in Fig. 7. Fig. 9 is an example of a print job to be executed.

[0054] (Step S11) The print control unit 111 of the control unit 11 reads the top print job in the print job reservation list. In the example shown in Fig. 9, the top job 1 is read. The print job includes print settings and print data (original image data). As shown in Fig. 9, the print settings include at least the paper color (paper attribute information) and enable / disable settings for image position correction.

[0055] (Step S12) The print control unit 111 performs background plane selection processing based on the print settings. This processing will be described with reference to the subroutine flowchart of FIG.

[0056] (Step S121) The print control unit 111 refers to the print settings and determines whether image position correction is enabled. If it is set to disabled, the print control unit 111 proceeds to step S122, and if it is set to enabled, the print control unit 111 proceeds to step S123. In the example of job 1 in FIG. 9, image position correction is set to "enabled."

[0057] (Step S122) The print control unit 111 selects the paper passing side (side 564).

[0058] (Step S123) The print control unit 111 acquires the paper color (paper information) in the print settings, and also refers to the table in Fig. 6 to determine whether this paper color is group 1 (light color) or group 2 (dark color). If it is group 1, the print control unit 111 advances the process to step S124, and if it is not group 1 (if it is group 2), the process advances to step S125.

[0059] (Step S124) The print control unit 111 selects background surface 1 (black) (surface 561). For example, in the example of job 1 in Fig. 9, since the paper color is white (group 1), background surface 1 (black) is selected.

[0060] (Step S125) The print control unit 111 selects background surface 2 (white) (surface 562). For example, if the paper color is black or blue (group 2), background surface 2 (white) is selected. With this, the print control unit 111 ends the process in FIG. 8, and returns to the process from step S13 onward in FIG. 7.

[0061] (Step S13) The print control unit 111 acquires setting information for the current background surface from the reading device control unit 112, and determines whether the current background surface (or surface) is different from the background surface selected in step S12. If the background surfaces of the two are the same, the print control unit 111 advances the process to step S15, and if they are different, the process advances to step S14.

[0062] (Step S14) The print control unit 111 controls the switching mechanism 57 via the control unit 31 through the reading device control unit 112 to switch to the background side selected in step S12. For example, if the paper passing side is selected in step S122, the switch is made to the paper passing side, and if background side 1 is selected in step S124, the switch is made to background side 1.

[0063] (Step S15) The print control unit 111 reads out the print data of the specified page based on the print settings, and transmits an instruction to the image forming unit 13 to prepare for image formation on the next sheet 90 .

[0064] (Step S16) The print control unit 111 transmits an instruction to the paper feed unit 25 of the paper feed device 20, via the other device control unit 113, to start feeding the next paper 90 from the paper feed tray 255 specified according to the print settings. The paper feed unit 25 feeds the paper 90 from the specified paper feed tray 255 and conveys it along the conveyance path 241. For example, in the case of job 1 in FIG. 9, the paper 90 is fed from tray 1.

[0065] (Step S17) The print control unit 111 refers to the print settings and determines whether image position correction is enabled. If it is set to disabled, the print control unit 111 proceeds to step S22, and if it is set to enabled, the print control unit 111 proceeds to step S18. In the example of job 1 in FIG. 9, image position correction is set to "enabled."

[0066] (Step S18) The print control unit 111 instructs the reading device 30 to read the paper 90 before image formation through the reading device control unit 112. The reading unit 50 reads the designated paper 90 in accordance with the timing at which the paper 90 is transported to the reading area of ​​the transport path 341, and generates read data (image data).

[0067] (Step S21) The reading device control unit 112 acquires the read data generated by the reading in step 21 from the reading device 30 and temporarily stores it in the storage unit 12. Then, the reading device control unit 112 notifies the correction value calculation unit 114 of this. The correction value calculation unit 114 recognizes the end of the paper 90 from the read data and recognizes the lengths and shapes of the four sides of the paper 90. In this case, when reading in step S18, the background surface that serves as the background of the paper 90 when reading, which is arranged opposite the reading sensor 51 (reading sensor), is set to a background surface of a color that has a high contrast with the paper color of the paper 90. Therefore, the correction value calculation unit 114 can accurately recognize the end of the paper 90 from the read data.

[0068] The correction value calculation unit 114 recognizes the paper size from the recognized lengths or shapes of the four sides, and calculates an image position correction value from the difference between the recognized paper size and the paper size in the print settings.

[0069] The correction value calculation unit 114 notifies the print control unit 111 of the calculated image position correction value through the reading device control unit 112. In job 1 shown in FIG. 9, the print control unit 111 uses it as a correction value for the image formation position on the back side (second surface) to match the image registration on the front and back sides (first and second surfaces). The print control unit 111 notifies the image forming unit 13 of the image position correction value to set it. The image forming unit 13 performs the above-mentioned correction according to the set image position correction value.

[0070] (Step S22) The print control unit 111 transmits an instruction to form an image on the next sheet of paper 90 to the image forming unit 13. The image forming unit 13 forms an image on the sheet of paper using the instructed print data. When forming this image, the image position of at least one of the first surface and the second surface is finely adjusted based on the image position correction value.

[0071] (Step S23) The print control unit 111 checks the print settings, and if there is a next page in the print job being executed, returns the process to step S15 and repeats the subsequent processes. On the other hand, if there is no next page, the process proceeds to step S24.

[0072] (Step S24) The print control unit 111 checks the print job reservation list, and if there is a next print job, returns the process to step S11 and repeats the subsequent processes. On the other hand, if there is no next print job, the operation of the device is stopped and the process is ended (END).

[0073] In this way, the reading device or image forming system according to this embodiment includes a reading sensor that optically reads paper conveyed along a conveying path, a background section disposed opposite the reading sensor across the conveying path and having a background surface that becomes the background of the paper when reading, and a control unit that switches the background surface of the background section based on attribute information of the paper being conveyed. With this configuration, even when paper of various colors is used, the edge position can be accurately detected, and by extension, the shape of the paper can be detected with high accuracy.

[0074] Second Embodiment Next, a reading device 30 and an image forming system 1000 according to a second embodiment will be described with reference to Fig. 10 to Fig. 13. Fig. 10 is a schematic diagram showing the main configuration of a reading unit 501 in the second embodiment. Fig. 11 is a table for explaining the use conditions of each surface of the background part.

[0075] As shown in Fig. 10, the reading unit 501 includes two sets of reading sensors 51a and 51b and background parts 56a and 56b. In the first embodiment, a reading sensor 51 having a reading area (y0-y100 in Fig. 3(a)) wider than the maximum paper width is used. In the second embodiment, two reading sensors 51a and 51b having a reading area (e.g., 297 mm) narrower than the maximum paper width are used, and the reading data of both sensors is combined to support reading of paper with the maximum paper width. Such two reading sensors 51a and 51b are used mainly from the viewpoints of marketability and cost.

[0076] Except for the length in the Y direction, each of the reading sensors 51a and 51b has the same configuration as the reading sensor 51 of the first embodiment. Also, each of the background parts 56a and 56b is the same as the background part 56, and has surfaces 561 to 564 (see FIG. 4). Also, each of the switching mechanisms 57a and 57b has the same configuration as the switching mechanism 57 of the first embodiment. The background part 56a is disposed opposite the reading sensor 51a across the conveying path 341, and the background part 56b is disposed opposite the reading sensor 51b. Hereinafter, a pair of the reading sensor 51a and the background part 56a is collectively referred to as the "reading part 1," and a pair of the reading sensor 51b and the background part 56b is collectively referred to as the "reading part 2." The reading sensors 51a and 51a are arranged adjacent to each other in the X direction (transport direction) with a gap of, for example, several mm, and are arranged so that at least a part of the reading area in the Y direction (width direction) is different. In the Y direction, the reading area of ​​the reading sensor 51a is in the range from y0a to y100a, and the reading area of ​​the reading sensor 51b is in the range from y0b to y100b. The overlapping area between the two sensors is in the range from y0b to y100a. The center c1 of the overlapping area in the Y direction and the center c1 of the transport of the paper 90 are aligned. Here, the length of the overlapping area in the Y direction is set to be equal to or greater than a predetermined value y. For example, the predetermined value y is 210 mm, and the length of the overlapping area is the same as this or several mm to several tens of mm longer than this.

[0077] FIG. 11 is a table for explaining the use conditions of the surfaces 561 to 564 of the background portion 56. These tables are stored in advance in the storage unit 12 or the storage unit 32. In these tables, groups 1 and 2 are classified based on the paper information described in the print settings (FIG. 6). In setting 1, the background surfaces of the reading units 1 and 2 are combined to have a predetermined brightness difference (combination of background surface 1 and background surface 2). In group 1 (light color), read data (hereinafter also referred to as read data 1) obtained by reading the reading sensor 51a set to background surface 1 (black) is used. In group 2 (dark color), read data (hereinafter also referred to as read data 2) obtained by reading the reading sensor 51b set to background surface 2 (white) is used. In settings 2 and 3, read data obtained by reading both reading sensors 51a and 51b is synthesized to generate one sheet of read data that fits the entire paper. The relative positional relationship of the XY coordinates of the reading sensors 51a and 51b is stored in advance in the storage unit 32 and is referred to when synthesizing.

[0078] (Background surface switching and printing) Next, the background switching process and the printing process executed by the image forming system 1000 according to the second embodiment will be described with reference to FIGS.

[0079] (Step S31) The process here corresponds to step S11 shown in FIG. 7, and therefore a description thereof will be omitted.

[0080] (Step S32) The print control unit 111 performs background plane selection processing based on the print settings. This processing will be described with reference to the subroutine flowchart of FIG.

[0081] (Steps S321 and S322) The processing here is the same as steps S121 and S122 shown in FIG. 8, and the description thereof will be omitted.

[0082] (Step S323) The print control unit 111 acquires the paper size (paper attribute information) based on the print settings. The print control unit 111 determines whether the paper size in the width direction is equal to or smaller than a predetermined value y (for example, 210 mm). If the paper size is equal to or smaller than the predetermined value y, the print control unit 111 advances the process to step S324, and if the paper size is larger than the predetermined value y, the print control unit 111 advances the process to step S325.

[0083] (Step S324) The print control unit 111 selects background surface 1 (black) and background surface 2 (white) for the reading units 1 and 2, respectively.

[0084] (Step S325) The print control unit 111 acquires the paper color (paper information) in the print settings, and also refers to the table in Fig. 6 to determine whether this paper color is group 1 (light color) or group 2 (dark color). If it is group 1, the print control unit 111 advances the process to step S326, and if it is not group 1 (if it is group 2), the process advances to step S327.

[0085] (Step S326) The print control unit 111 selects background surface 1 (black) for both reading units 1 and 2.

[0086] (Step S327) The print control unit 111 selects the background surface 2 (white) for both reading units 1 and 2. With this, the print control unit 111 ends the processing in FIG. 13, and returns to the processing from step S33 onward in FIG.

[0087] (Steps S33-S38) The processing here is the same as steps S13-S18 shown in Fig. 8, and the description will be omitted. In step S28, the two reading sensors 51a and 51b read the conveyed paper 90 and generate two pieces of read data (read data 1 and 2).

[0088] (Step S401) The print control unit 111 acquires the paper size based on the print settings. The print control unit 111 determines whether the paper size in the width direction is equal to or smaller than a predetermined value y (for example, 210 mm). If the paper size is equal to or smaller than the predetermined value y, the print control unit 111 advances the process to step S402, and if the paper size is larger than the predetermined value y, the print control unit 111 advances the process to step S403.

[0089] (Step S402) The print control unit 111 uses one of the read data 1 and 2. Specifically, if the paper is in group 1 (light color), the read data 1 is used, and if the paper is in group 2 (dark color), the read data 2 is used.

[0090] (Step S403) The print control unit 111 uses both the read data 1 and 2 (uses the combined data).

[0091] (Step S41) The reading device control unit 112 acquires the read data 1 and 2 generated by the reading in step 38 from the reading device 30 and temporarily stores them in the storage unit 12. Then, the reading device control unit 112 notifies the correction value calculation unit 114 of this. Based on the determination in steps S402 and S403, the correction value calculation unit 114 recognizes the edge of the paper 90 using either the read data 1 or 2, or the combined data of these, and recognizes the lengths and shapes of the four sides of the paper 90.

[0092] (Steps S42-S44) The processing here is similar to steps S22-S24 shown in FIG. 8, and the description thereof will be omitted.

[0093] In this way, in the second embodiment, as in the first embodiment, the background surface of the paper 90 placed opposite the reading sensor 51 when reading is set to a background surface of a color that has a high contrast with the paper color of the paper 90. Or, the read data (read data 1 or read data 2) obtained by reading with the background surface set to such a high contrast color is used. Therefore, the correction value calculation unit 114 can accurately recognize the edge of the paper 90 from the read data. Also, in the second embodiment, when a print job using a paper 90 with a width size of a predetermined value y or less and a paper of a different color is continued, it is possible to deal with this by selecting the read data to be used without switching the background surface in the reading units 1 and 2. In other words, even if a waiting time occurs due to switching of the background surface, the waiting time is not generated and a decrease in productivity can be suppressed.

[0094] The above-described configuration of the reading device 30 and the image forming system 1000 equipped with the same are merely the main configurations described in the description of the features of the above embodiment, and are not limited to the above configurations and may be modified in various ways within the scope of the claims. Furthermore, configurations equipped in general image forming devices are not excluded.

[0095] 7 and 12, an example has been shown in which the control unit 11 (print control unit 111) of the image forming apparatus 10 mainly performs the processing related to the switching of the back side and the generation of the read data. However, the present invention is not limited to this, and the control unit 31 of the reading device 30 mainly performs the processing related to the switching of the back side and the generation of the read data. In this case, the reading device 30 obtains paper information (color information, size information) of the paper 90 being conveyed from the control unit 11 on the main body side, and performs the switching control of the back side or the selection of the read data to be used (S402, S403 in the second embodiment) according to the obtained paper information.

[0096] 7 and 12, a case where a single print job uses paper of a common color and size is described as an example, but this is not limited to this. For example, if a single print job is a mixed color paper job, the process from step S12 (or S32) onward may be performed for each page or for each page where the color paper changes.

[0097] Also, the color information of the paper is set by the user via the operation panel 18 or the like in the above example, but is not limited to this. As another example, a detection sensor that detects color or density (brightness) may be disposed in the paper feed unit 25 or the transport path 241, 341 from the paper feed tray 255 to the reading unit 50, and the control unit 11 may select the background surface based on the detection value of this detection sensor.

[0098] In addition, the means and methods for performing various processes in the reading device 30 and the image forming system 1000 according to the above-mentioned embodiment can be realized by either a dedicated hardware circuit or a programmed computer. The above-mentioned program may be provided by a computer-readable recording medium such as a USB memory or a DVD (Digital Versatile Disc)-ROM, or may be provided online via a network such as the Internet. In this case, the program recorded in the computer-readable recording medium is usually transferred to and stored in a storage unit such as a hard disk. In addition, the above-mentioned program may be provided as a standalone application software, or may be incorporated into the software of the device as one of its functions. [Explanation of symbols]

[0099] 1000 Image forming system 10 Image forming device 11 Control section 111 Printing control unit 112 Reading device control unit 113 Other device control section 114 Correction value calculation unit 12 Storage section 13 Image forming section 20 Paper feeder 24 Conveyor 25 Paper feed section 30 Reading device 31 Control Unit 32 Storage section 34 Conveyor 341 Transport Path 39 Communications Department 40 Aftertreatment device. 50, 501 Reading unit 51, 51a, 51b reading sensor 56, 56a, 56b Background section 561 Background surface 1 562 Background surface 2 563 Calibration Surface 564 Paper passing side 57 Switching Mechanism

Claims

1. a conveying section that conveys paper along a conveying path; a reading unit including a reading sensor that optically reads the paper conveyed through the conveying path; A control unit that controls the reading unit, the reading unit includes a background unit disposed opposite the reading sensor across the transport path, the background unit having a background surface that becomes a background of the paper when reading; The control unit switches the background surface of the background unit based on attribute information of the paper being transported.

2. the background portion has a plurality of background surfaces having different colors or brightnesses; the attribute information of the paper is information on the color of the paper, The reading device according to claim 1 , wherein the control unit switches the background surface based on information about a color of a paper sheet.

3. The reading device according to claim 1 , wherein the reading section reads an edge of a paper sheet transported on the background surface.

4. the background portion has a first background surface and a second background surface having a different brightness from that of the first background surface, The reading device according to claim 2 , wherein the control unit switches to a background surface having a greater brightness difference with respect to the color of the paper being conveyed.

5. The reading unit includes a first reading sensor and a second reading sensor, a first background portion disposed opposite the first reading sensor and a second background portion disposed opposite the second reading sensor, The reading device according to claim 1 , wherein the control unit switches the background surface of the first background portion and the background surface of the second background portion based on attribute information of the paper.

6. each of the first and second background portions has a plurality of background surfaces having different colors or brightnesses; The paper attribute information includes information on the size of the paper, The reading device according to claim 5 , wherein the control unit switches the background surface of the first background portion and the background surface of the second background portion based on a size of a paper sheet.

7. 7. The reading device according to claim 6, wherein the first reading sensor and the second reading sensor are disposed adjacent to each other in a paper transport direction and are disposed such that at least a portion of the reading area differs in a width direction perpendicular to the transport direction.

8. the first reading sensor and the second reading sensor have reading areas that overlap in the width direction; 8. The reading device according to claim 7, wherein the control unit controls a combination such that a background surface of the first background portion and a background surface of the second background portion have a brightness difference of a predetermined value or more when the size of the paper in the width direction is equal to or smaller than a predetermined value.

9. a paper feed section that feeds paper; A reading device according to any one of claims 1 to 8, an image forming unit that forms an image on the paper conveyed from the reading device; a correction value calculation unit that calculates a paper position correction value based on read data obtained by reading the paper by the reading device; and a print control unit that adjusts an image formation position on at least one of a first side and a second side of the read paper based on the paper position correction value calculated by the correction value calculation unit.

10. a paper feed section that feeds paper; a conveying section that conveys paper along a conveying path; a reading unit including a reading sensor that optically reads the paper conveyed through the conveying path; an image forming unit that is located downstream of the reading unit in the conveying path and that forms an image on the conveyed paper; A control unit that controls the reading unit, the reading unit includes a background unit disposed opposite the reading sensor across the transport path, the background unit having a background surface that becomes a background of the paper when reading; The control unit switches the background surface of the background unit based on attribute information of the paper being transported.

11. a paper feed section that feeds paper; a conveying section that conveys paper along a conveying path; a reading unit including a reading sensor that optically reads the paper conveyed along the conveying path; an image forming unit that is disposed in a conveyance path downstream of the reading unit and that forms an image on conveyed paper, the reading unit includes a background unit disposed opposite the reading sensor across the transport path, the background unit having a background surface that becomes a background of the paper when reading; A control program that executes a process of switching the background surface of the background portion based on attribute information of the paper being conveyed.

Images