Image inspection device and image forming device

Abstract

To distinguish, when an abnormality occurs, whether a folded corner occurs or wrinkles occur.SOLUTION: An image inspection device comprises: a reading unit that reads an image of a medium to be conveyed; and an image control unit that determines the presence or absence of wrinkles in and a folded corner of the medium based on whether a plurality of positions on the image of the medium read by the reading unit satisfy a predetermined relationship. The image control unit determines the presence or absence of wrinkles in the medium based on the predetermined relationship, and subsequently determines the presence or absence of a folded corner of the medium.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention relates to an image inspection device and an image forming device. [Background technology]

[0002] There are various conventional techniques for detecting abnormalities in paper. For example, Patent Document 1 discloses a configuration for detecting the variation of the edge of paper and calculating the amount of variation in order to detect folded edges. Patent Document 2 discloses a configuration for recognizing the outer edge shape of a recording medium and determining the parallelism of at least one pair of two opposing sides of the outer edge shape in order to detect paper wrinkles. Summary of the Invention [Problem to be solved by the invention]

[0003] The above-mentioned Patent Document 1 discloses a method for detecting folded edge of paper, and the above-mentioned Patent Document 2 discloses a method for detecting wrinkles in paper. However, when attempting to detect folded edge and wrinkles simultaneously, there is a problem in that when an abnormality occurs, it is impossible to distinguish whether a folded edge or a wrinkle has occurred.

[0004] The present invention aims to provide an image inspection device and an image forming device that are capable of distinguishing, when an abnormality occurs, whether a folded edge or a wrinkle has occurred. [Means for solving the problem]

[0005] The image inspection device according to the present invention includes a reading unit that reads an image of a medium being conveyed, and an image control unit that determines whether or not the medium has wrinkles and bent edges based on whether a plurality of positions on the image of the medium read by the reading unit satisfy a predetermined relationship, and the image control unit determines whether or not the medium has wrinkles based on the predetermined relationship, and then determines whether or not the medium has bent edges. The distance between the edges of the medium is calculated as the predetermined relationship, and the presence or absence of wrinkles in the medium is determined based on the distance. The present invention is configured as an image inspection device characterized by the above. Effect of the Invention

[0006] According to the present invention, when an abnormality occurs, it can be distinguished whether a folded edge or a wrinkle has occurred. [Brief description of the drawings]

[0007] [Figure 1] 1 is a diagram showing an outline of a mechanical configuration of an image forming system according to an embodiment of the present invention; [Diagram 2] FIG. 1 is a diagram showing one embodiment of the present invention (part 1). [Diagram 3] FIG. 2 is a diagram showing an embodiment of the present invention (part 2). [Figure 4] FIG. 3 is a diagram showing an embodiment of the present invention (part 3). [Diagram 5] FIG. 4 is a diagram showing a method for measuring the distance between the edges of a sheet of paper in one embodiment of the present invention. [Figure 6] 10 is a flowchart showing a procedure for determining the occurrence of wrinkles in another embodiment of the present invention. [Figure 7] 11A and 11B are diagrams for explaining a method for simultaneously determining whether a sheet has bent edges and whether the sheet has wrinkles; [Figure 8] 11A and 11B are diagrams for explaining a method for determining whether a sheet has a folded edge after determining whether the sheet has a wrinkle. [Figure 9] FIG. 13 is a diagram showing an example of a setting screen for detecting a defect determination mode. [Figure 10] 10 is a flowchart showing a processing procedure for setting transport conditions and fixing conditions. [Figure 11] FIG. 13 is a diagram showing an example of a screen for selecting, setting, or changing fixing conditions and transport conditions according to the type of paper and environmental conditions. [Figure 12] 13 is a diagram showing another example of the screen for accepting selection, setting, and change of fixing conditions and transport conditions according to the paper type and environmental conditions. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The image inspection device and the image forming device equipped with the image inspection device in this embodiment have the following features when detecting paper defects. In short, when determining defects in paper, the feature is that after determining wrinkles, a determination is made of folded edges. The above-mentioned features of the present invention will be explained in detail with reference to the drawings below. In the following, an example of a medium is shown in which paper is used, but the same can be considered for sheet-like media other than paper, for example.

[0009] Fig. 1 is a diagram showing an example of an image forming system in this embodiment. As shown in Fig. 1, the image forming system 1 has an image forming apparatus 10 that forms images, and a paper feeder 40 is connected to the upstream side, which is the front stage of the image forming apparatus 10. A reading apparatus 20 is connected to the downstream side, which is the rear stage of the image forming apparatus 10, and a post-processing apparatus 30 is further connected to the downstream side, which is the rear stage of the reading apparatus 20. Each apparatus and the apparatus main body are electrically and mechanically connected, and communication between the respective apparatuses and paper transport are possible.

[0010] In this embodiment, the image forming system 1 is configured by the image forming apparatus 10, the paper feeder 40, the reading device 20 and the post-processing device 30, but the image forming system may be configured by only the image forming apparatus 10, or by adding other devices to the image forming apparatus 10, or may be configured by only the reading device 20. Furthermore, in the following, the image forming apparatus 10 performs image formation and judgment of paper wrinkles and folded edges, which will be described later, but the image forming apparatus 10 may perform image formation, and judgment of paper wrinkles and folded edges, which will be described later, may be configured as an image inspection apparatus included in the image forming apparatus 10 (or an image inspection apparatus in a separate housing from the image forming apparatus 10).

[0011] The sheet feeding device 40 includes a plurality of sheet feeding stages, and sheets are stored in each of the sheet feeding stages. The sheets stored in the sheet feeding stages can be supplied to the image forming device 10 installed in the subsequent stage.

[0012] A transport path 13 is provided within the housing of the image forming apparatus 10, and paper supplied from the paper feeder 40 or the main body paper feed unit 12 is transported downstream along the transport path 13. An image forming unit 11 that forms an image on the paper is provided near the middle of the transport path 13.

[0013] The image forming unit 11 has photoconductors 11a for each color (cyan, magenta, yellow, black), and is provided with a charger, LD (laser diode), developer, cleaning unit, etc. (not shown) around the photoconductor 11a. The image forming unit 11 also has an intermediate transfer belt 11b at a position where it contacts the photoconductors 11a for each color. The intermediate transfer belt 11b contacts the paper on the conveying path 13 at a secondary transfer unit 11c provided midway along the intermediate transfer belt 11b. Further, in the conveying path 13, a fixing unit 11d including a fixing roller 11e is provided at a position downstream of the secondary transfer portion 11c.

[0014] When forming an image on a sheet of paper, the photoconductor 11a is uniformly charged by the charger, and then the photoconductor 11a is irradiated with laser light from the LD to form a latent image on the photoconductor 11a. The latent image on the photoconductor 11a is developed into a toner image by a developing unit, and the toner image on the photoconductor 11a is transferred to the intermediate transfer belt 11b, and the image on the intermediate transfer belt 11b is transferred to the sheet of paper at the secondary transfer unit 11c. The sheet of paper on which the image has been formed is transported along the transport path 13, and the image is fixed by the fixing unit 11d.

[0015] In this embodiment, the image forming unit 11 has been described as forming a color image, but in the present invention, the image forming unit 11 may form a monochrome image such as black. Also, a reversing conveying path may be provided before and after the image forming unit 11, and the paper may be reversed and conveyed, thereby enabling image formation on both sides of the paper. Also, the image forming apparatus 10 is provided with an operation unit 140 on the upper part of the housing. The operation unit 140 has an LCD 141 with a touch panel and a group of operation keys such as a numeric keypad, and is capable of displaying information and receiving operation input. The operation unit 140 serves as both a display unit and an operation unit.

[0016] In this embodiment, the operation unit 140 is an integrated unit of the operation unit and the display unit, but the operation unit and the display unit may not be integrated, and for example, the operation unit may be configured by a mouse, a tablet, a terminal, etc. Also, the LCD 141 may be movable.

[0017] An automatic document feeder (ADF) 18 is provided on the upper part of the housing of the image forming apparatus 10 at a location where the operation unit 140 is not located. The automatic document feeder (ADF) 18 automatically feeds a document set on a document placement table, and the document fed by the automatic document feeder (ADF) 18 is read by a scanner unit 130 shown in FIG. 2. The document can also be read on a platen glass (not shown). The scanner unit 130 can also set a printed matter output from the image forming system 1 and read it. For example, a sheet of paper on which a printing image or an adjustment image is formed can be set and read to obtain a read image. In this case, the scanner unit 130 corresponds to the image reading unit of the present invention.

[0018] The image forming apparatus 10 also has an image control unit 100. The image control unit 100 controls the entire image forming system 1, and is composed of a CPU, a memory, and the like. The image control unit 100 may be provided outside the housing of the image forming apparatus. The program that runs on the CPU includes the program of the present invention.

[0019] The reading device 20 has a conveying path 23, and the paper introduced from the image forming device 10 is conveyed along the conveying path 23. The downstream side of the conveying path 23 is connected to a post-processing device 30 at the subsequent stage. Near the middle of the conveying path 23, there are provided an image reading unit 24 that reads an image on the bottom surface of the paper conveyed on the conveying path 23, and an image reading unit 25 that reads an image on the top surface of the paper. The image reading unit 24 is located upstream of the image reading unit 25.

[0020] The image reading units 24 and 25 can be configured with a line sensor such as a CCD sensor or a CMOS sensor, and can read the image of the paper conveyed on the conveying path 23 over the entire direction intersecting the conveying direction. The reading result read by the image reading unit 24 or the image reading unit 25 is once sent to the reading control unit 200 provided in the reading device 20, and the reading result is transmitted from the reading control unit 200 to the image control unit 100. The image control unit 100 can determine whether or not wrinkles have occurred on the paper based on the reading result. The reading result may be obtained by reading one side of the paper, or may be obtained by reading both sides of the paper.

[0021] In this embodiment, the two image reading units are capable of reading images on the front and back of the paper, but the number of image reading units is not particularly limited. There may be only one image reading unit, or a reversing transport path may be provided before and after the image reading unit to reverse and transport the paper, thereby allowing the single image reading unit to read images on the front and back of the paper.

[0022] In this embodiment, the reading result is transmitted to the image control unit 100, enabling the image control unit 100 to determine whether the paper is wrinkled, but the reading control unit 200 provided in the reading device 20 may be configured to determine whether the paper is wrinkled. The determination result can be transmitted to the image control unit 100.

[0023] The post-processing device 30 has a transport path 33 and transports the paper introduced from the reading device 20 downstream. A post-processing unit (not shown) is provided midway along the transport path 33. The post-processing unit can execute predetermined post-processing, such as stapling and punching, as well as post-processing including folding, such as inner triple folding, saddle stitching, Z-folding, gate folding, and quarter folding. The post-processing unit may execute multiple post-processing processes.

[0024] Further, a conveying path 34 branches off from the conveying path 33 midway. The conveying path 33 is connected to the first paper discharge section 31, and the conveying path 34 is connected to the second paper discharge section 32. Paper that has undergone post-processing is discharged to the first paper discharge section 31, and paper that has not undergone post-processing is discharged to the second paper discharge section 32. Furthermore, if it is determined that the paper is wrinkled, the wrinkled paper may be discharged to a different paper discharge destination from the normal paper discharge destination. Paper that will not undergo post-processing may be discharged to the second paper discharge section 32.

[0025] Furthermore, the image forming system 1 includes a reading device 20, but the reading device 20 may be provided within the housing of the image forming device, and the image forming device and the reading device may not be mechanically connected. The image forming system of the present invention may include an image reading unit, or may not include an image reading unit. Furthermore, the image forming system of the present invention may include an image forming unit, or may not include an image forming unit.

[0026] In this embodiment, the transport path (and the mechanism for transporting the paper via these transport paths) that transports the paper from the paper feeder 40 through the image forming unit 11, the reader 20, and the post-processing unit 30 in the device main body 10 to the paper discharge tray 31 or the second paper discharge unit 32 may be referred to as the transport unit. Also, the reader 20 may be referred to as the in-line sensor or the reading unit.

[0027] Next, the determination of folded edge and wrinkles in the paper in this embodiment will be described. The folded edge of the paper can be determined, for example, as follows. Fig. 2 explains the cut-out means in the image control unit 100 (paper cut-out position calculation means). First, if the paper length is "1" and the positions of the left and right upper ends of the paper are (x0, y0) and (x1, y1), respectively, then, for example, if (y1-y0)>0, that is, if the paper is skewed upward to the right, then

[0028]

number

[0029]

number

[0030]

number

[0031] Thus, the x dot value X of the rightmost edge is obtained. FIG. 3 explains the processing in the image control unit 100 (edge ​​crease paper detection means). 2, y2),(x 3, If the ratio of the increment of the X coordinate and the increment of the Y coordinate of (y1-y3) is not equal (or exceeds a certain value), that is, if (x2-x0):(x3-x1) ≠ (y0-y2):(y1-y3), it is considered to be an edge break.

[0032] Fig. 4(a) explains the calculation means for the original edge position of folded paper as shown in Fig. 3, specifically, the processing by the left and right edge detection means and the left and right top end calculation processing means for folded paper (both are in the image control unit 100). For example, when the top right end is folded as shown in Fig. 4(a), the positions detected by the top end edge detection means (paper leading edge detection means) are (x0, y0) and (x1, y1) on the left and right, respectively.

[0033] The left and right edge detection means detects the left and right edges of the nth line below. The value of n of the nth line is determined by descending the line until the increments of the x and y coordinates become equal, and then detecting the coordinates of the left and right edges of the previous line (xm When the increments at the coordinates (xm+1, ym+1), (xn+1, yn+1) of the left and right edges of the next line become equal, the right end coordinates (xn, yn) of the line are determined to be the end position of the edge bend.

[0034] That is, when the increment ratio of the left edge and the right edge becomes equal, it can be regarded as the end point of the edge bend. Therefore, the upper right edge to be found is the two points (x0, y0) and (x1, y1) shown in FIG. 4 and the two points (x n ,y n ),(x n+1 ,y n+1 ) is the intersection point X of the lines connecting In other words,

[0035]

number

[0036]

number

[0037] Using the top edge position of the folded paper calculated in this manner, the cut-out position X is calculated in the same manner as described in FIG.

[0038] Furthermore, wrinkles in paper may be determined, for example, as follows: After reading the paper, the outer edge shape is recognized using the obtained reading result, the distance X between the paper edges in the paper-passage cross direction at an arbitrary position in the paper-passage direction on the outer edge shape is calculated, and the distance Y between the paper edges in the paper-passage cross direction is calculated at a position different from the calculated position. Note that the distance between the paper edges in the paper-passage cross direction is the distance between two opposing sides along the paper-passage direction. The positions at which the distances X and Y are calculated are not particularly limited, but the measurement positions can be determined based on the distance from the leading edge corner of the paper, for example.

[0039] An overview of the calculation positions for the distance between the paper edges is shown in Figure 5. The positions for measuring the X and Y distances are set so that the respective distances are parallel. In the example of Figure 5, the distance between the edges is measured at two points, but in addition to this, the distance between the paper edges can also be calculated at other positions to obtain the parallelism.

[0040] In this example, the presence or absence of wrinkles is judged based on whether the two sides along the paper feed direction are parallel. However, it is also possible to judge whether the two sides along the paper feed cross direction are parallel, and based on the judgment result, It is also possible to determine the presence or absence of wrinkles, and the accuracy of the determination may be improved by combining these. Furthermore, the operation after the wrinkle determination is not particularly limited, and the paper on which the wrinkles are detected may be discharged as waste to a different paper discharge destination from the normal one, image formation may be stopped at the point when the wrinkles are detected, and further, the output may be continued. If the occurrence of wrinkles is continuous for a predetermined number of sheets or occurs at a predetermined frequency, the output may be stopped.

[0041] In the above example, the occurrence of wrinkles is judged only by the parallelism of the two opposing sides, but the occurrence of wrinkles may be judged by other factors in addition to the parallelism. In the following example, the occurrence of wrinkles is judged by whether there is a continuous density change in the paper feed direction in the read image. The procedure of the above operation will be explained based on the flowchart in FIG. 6. The following procedure is executed under the control of the image control unit 100.

[0042] First, the output paper is read by the image reading unit (step s10). The paper may be read only on one side even when double-sided printing is performed. After the paper is read, the acquired reading result is used to recognize the outer edge shape, and the distance X between the paper edges in the cross-paper passing direction at any position on the outer edge shape is calculated (step s11), and the distance Y between the paper edges in the cross-paper passing direction is calculated at a position different from step s11 (step s12).

[0043] After calculating the distances X and Y between the paper edges, it is determined whether X=Y (step s13). If X=Y (step s4, Yes), the two opposing sides along the paper feed direction are parallel, so the determination result is that there is no wrinkle (step s17), and the procedure ends. If X=Y does not occur (step s13, No), the two opposing sides are not parallel, so it is determined that there may be wrinkles, and it is determined whether there is a continuous density change in the paper feed direction in the read image (step s14). If there is a continuous density change in the paper feed direction in the read image (step s14, Yes), it is determined that this is due to wrinkles, so there is a possibility that wrinkles have occurred, and it is determined whether the density change point is darker than the surroundings (step s15).

[0044] If there is no continuous density change in the paper feed direction within the read image (step s14, No), it is determined that no wrinkles have occurred (step s17), and the procedure ends. If the density change point is not darker than the surroundings (step s15, No), it is determined that no wrinkles have occurred (step s17), and the procedure ends. If the density change point is darker than the surroundings (step s15, Yes), it is determined whether the density change is longer than a threshold (step s16). The threshold can be set appropriately, and may be set based on empirical values, etc.

[0045] If the density change is not longer than the threshold (step s16), it is determined that the density change may be caused by something other than wrinkles, and no wrinkles are detected (step s17), and the procedure ends. If the density change is longer than the threshold (step s16), it is determined that wrinkles are detected (step s18), and then the procedure ends. According to the above procedure, the occurrence of wrinkles is determined based on the density change of the image in addition to the parallelism, which has the effect of improving the determination accuracy.

[0046] Wrinkles on paper are likely to occur when an image on the paper is fixed by a fixing roller. The fixing roller applies heat and pressure to the paper based on a preset temperature and pressure to fix the image, but if wrinkles occur on the paper, the fixing pressure or fixing temperature may not be appropriate, which may be the cause of the wrinkles. To deal with this, when wrinkles are found, the machine settings that are thought to be caused by the wrinkles can be adjusted. The machine settings may be adjusted when wrinkles occur continuously on a predetermined number of sheets or at a predetermined frequency, or the machine settings may be controlled to be set by a user's operation.

[0047] Although it is possible to judge whether the paper has bent edges or wrinkles as described above, a method of judging both at the same time will be described below. In the following, by having separate measurement points for judging each paper defect, it is possible to judge whether the paper has bent edges or wrinkles at the same time.

[0048] Fig. 7 is a diagram for explaining a method for simultaneously determining whether a paper edge is folded and whether the paper is wrinkled. As shown in Fig. 7, the image control unit 100 sets, as feature points, four measurement positions of xy coordinates for determining whether the edge is folded and four measurement positions of αβ for wrinkle detection in the paper image read by the reading device 20, which is an inline sensor. In Fig. 7, feature points (x0, y0), (x1, y1), (x2, y2), and (x3, y3) are set for determining whether the edge is folded, and feature points (α1, β1), (α2, β2), (α3, β3), and (α4, β4) are set for wrinkle detection.

[0049] The image control unit 100 judges that a bent edge 701 has occurred when the relationship between these feature points satisfies the formula (x2-x0):(x3-x1) ≠ (y0-y2):(y1-y3) shown in Fig. 7, and judges that a wrinkle 702 has occurred when (β1-β3) ≠ (β2-β4). In other words, when these conditions are satisfied, it is judged that defects have occurred due to both bent edges and wrinkles in the paper. Note that the above x and α represent coordinates in the main scanning direction, and y and β represent coordinates in the sub-scanning direction.

[0050] The image control unit 100 stores the above-mentioned judgment results in a storage area such as a memory, and, by any setting, discharges the paper judged to be defective to a tray separate from normal paper. For example, the image control unit 100 discharges the paper not judged to be defective to the paper discharge tray 31 of the post-processing device, and discharges the paper judged to be defective to the second paper discharge unit 32 of the post-processing device. Furthermore, when the image control unit 100 judges that a paper is defective, it may output information to that effect to a display device such as a display, to notify the user.

[0051] In the above-mentioned method, there are cases where, especially when only wrinkles occur, the image control unit 100 makes a two-step judgment, first performing a wrinkle judgment, and then proceeding to a bent edge judgment if there is no problem. That is, when judging defects in a sheet, it is possible to distinguish between wrinkles and bent edge judgments by performing a wrinkle judgment and then a bent edge judgment. FIG. 8 is a diagram for explaining a method of performing a bent edge judgment after a wrinkle judgment on a sheet. In FIG. 8, the image control unit 100 judges that a wrinkle 801 has occurred if (β1-β3)≠(β2-β4) is satisfied. Then, when the image control unit 100 judges that a wrinkle 801 has not occurred in the judgment, it further judges whether or not (x2-x0):(x3-x1)≠(y0-y2):(y1-y3) is satisfied, and when it is judged that the formula is satisfied, it judges that a bent edge has occurred. In this way, by using the above-described two-stage judgment, when an abnormality occurs, it is possible to distinguish whether a paper defect such as a folded edge has occurred or a paper defect such as a wrinkle has occurred.

[0052] Furthermore, as will be described below, a defect determination mode for determining defects may be selectable.

[0053] FIG. 9 is a diagram showing an example of a setting screen for detecting a defect determination mode. As shown in FIG. 9, the user can select from two modes on the operation unit 140: a mode 901 for determining only the presence or absence of wrinkles, and a mode 902 for determining both wrinkles and bent edges. For a user who cuts the margins of a printed matter, bent edges at the edge of the paper are often not a big problem. In that case, the user can select a mode for determining only wrinkles (the "Wrinkle only" button in the figure below), and can detect wrinkles in the paper and determine defects with higher accuracy. Note that when the mode 902 is selected, as described above, after the wrinkle determination, bent edges are determined. Of course, although not particularly shown in FIG. 9, a mode for bent edges may be selected.

[0054] Further, a control for changing the discharge destination of the paper according to the judgment result will be described. The image control unit 100 changes the discharge destination when it is judged that there are wrinkles and when it is judged that there are folded edges. For example, the image control unit 100 discharges the paper to the second discharge unit 32 of the post-processing device when it is judged that there are wrinkles, and discharges the paper to the discharge tray 31 of the post-processing device when it is judged that there are folded edges. When a user visually checks the degree of defect of a paper judged to be defective, by separating the discharge trays according to wrinkles and folded edges, the user can easily find the paper judged to be defective. In addition, since the discharge trays differ according to the type of defect, the user can easily grasp how many sheets of paper have what type of defect. The image control unit 100 may display such changes and settings of the discharge destination of the paper on a screen similar to the screen for selecting the mode shown in FIG. 9, and allow the user to select it. Furthermore, in addition to when it is determined that there are wrinkles or that there are folded edges, the image control unit 100 can also change the discharge destination to a different destination when it is determined that there are both wrinkles and folded edges.

[0055] Furthermore, when it is determined that there are wrinkles, the fixing conditions (fixing temperature, fixing pressure, etc.) may be changed. FIG. 10 is a flowchart showing a process procedure for setting the conveying conditions and the fixing conditions. As shown in FIG. 10, when the paper is read (S1001), the image control unit 100 determines whether there are wrinkles (S1002). When it is determined that there are wrinkles (S1002; Yes), the image control unit 100 further determines whether there are bent edges (S1003). When it is determined that there are bent edges (S1003; Yes), the image control unit 100 changes the fixing conditions (fixing temperature, fixing pressure, etc.) and further changes the conveying conditions (rotation speed of the conveying roller, etc.) since both wrinkles and bent edges have occurred (S1004). In this way, when it is determined that there are both wrinkles and bent edges, both the fixing conditions and the conveying conditions are changed. By changing the fixing conditions (fixing temperature, fixing pressure, etc.), it is possible to reduce wrinkles in the next and subsequent papers. In addition, by changing the transport conditions (such as the rotation speed of the transport rollers), it is possible to reduce edge folding in subsequent sheets. Specifically, the rotation speed of the transport rollers is preset for each paper feed tray, and if edge folding occurs, the rotation speed is slowed down to prevent edge folding.

[0056] In S1003, if the image control unit 100 determines that there is no bent edge (S1003; No), it determines that only wrinkles have occurred, and reduces wrinkles in the next and subsequent sheets of paper by changing the fixing conditions described above (fixing temperature, fixing pressure, etc.) (S1005).

[0057] Furthermore, in S1002, if the image control unit 100 determines that there are no wrinkles (S1002; No), it further determines whether or not there are folded edges (S1006). If the image control unit 100 determines that there are folded edges (S1006; Yes), it changes the above-mentioned conveying conditions (such as the rotation speed of the conveying roller) to reduce the folding edges of the next and subsequent sheets (S1007).

[0058] On the other hand, when the image control unit 100 determines that there is no edge folding (S1006; No), it determines that there is no paper defect (S1008). The above conditions may be changed automatically by changing the amount of adjustment determined based on a table preset in the machine, or may be changed by having the user input the amount of adjustment through the operation unit 140.

[0059] Furthermore, the above-mentioned fixing conditions and transport conditions may be selected, set, or changed according to the paper type and environmental conditions. When the image control unit 100 determines that the paper has wrinkles or bent edges, or both, the image control unit 100 automatically or manually records the fixing conditions and transport conditions at that time in a storage area such as a memory. Also, as shown below, the image control unit 100 automatically or manually records the fixing conditions and transport conditions after being changed in response to the determination that the paper has wrinkles or bent edges, or both, in a storage area such as a memory. Then, when printing is performed thereafter, the image control unit 100 detects the temperature and humidity and the paper type of each paper feed tray, calls up the fixing conditions and transport conditions recorded for that paper type, and presents information for prompting the user to decide whether to reflect or not reflect the conditions when printing.

[0060] FIG. 11 is a diagram showing an example of a screen that accepts the selection, setting, and change of the fixing conditions and transport conditions described above according to the paper type and environmental conditions. As shown in FIG. 11, the image control unit 100 determines the paper type of the paper in the paper feed tray from the type of the paper feed tray. When printing paper of the same paper type as the determined paper type, the image control unit 100 reads out the fixing conditions and transport conditions recorded when the paper of the same paper type was determined to have wrinkles, bent edges, or both when printed in the past from the storage area such as the memory, and displays them on the screen of the operation unit 140. In addition, the image control unit 100 compares the current temperature and humidity around the device when printing paper of the same paper type with the temperature and humidity around the device when the paper of the same paper type was determined to have wrinkles, bent edges, or both when printed in the past. The image control unit 100 compares the two and displays those that are similar to each other by a certain degree or more on the operation unit 140 in order of similarity. The temperature and humidity around the device may be measured by a sensor or thermometer / hygrometer installed on the device body, or the measurement results may be received and obtained from a sensor or thermometer / hygrometer installed outside the device body via a communication device, such as wirelessly.

[0061] In Fig. 11, image control unit 100 displays information 1101 indicating that paper of the paper type in the paper feed tray of tray 1 that is currently being printed on has previously developed wrinkles, bent edges, or both when printed under an environment at least a certain level close to the current temperature and humidity, and information 1102 indicating a recommendation to change the fixing conditions and transport conditions. Furthermore, image control unit 100 displays, together with this information, information 1103 indicating the current temperature and humidity, and the past temperature and humidity that are closest to the current environment. Fig. 11 shows, for example, that when paper of the paper type in tray 1 was previously printed at a temperature of 32.5°C and a humidity of 86.2%, wrinkles, bent edges, or both occurred on the paper.

[0062] In FIG. 11, information indicating the past temperature and humidity closest to the current environment is displayed. However, as shown in FIG. 12, among past temperatures and humidities when printing was performed under an environment close to the current temperature and humidity, a plurality of candidates (three candidates in FIG. 12) may be displayed in order from the closest. Furthermore, the image control unit 100 may display the conveying conditions such as the roller speed and the fixing conditions such as the fixing temperature at that time in association with each of the displayed plurality of candidates. In FIG. 12, three conditions are selected from the conditions closest to the current environment, and are displayed on the operation unit 140 in association with the plurality of candidates. In FIG. 12, an example is shown in which a paper of the paper type of the tray 1 is printed at a current temperature of 32.3° C. and humidity of 85.4%. The image control unit 100 reads out the top three temperatures and humidities that are closer to the current temperature and humidity by a certain amount or more from the storage area such as the memory, among the temperatures and humidities when the paper of the paper type of the tray 1 was printed in the past and wrinkles, bent edges, or both occurred on the paper, and displays them on the screen of the operation unit 140. Furthermore, image control unit 100 displays, in association with these temperatures and humidities, fixing conditions and transport conditions that have been changed automatically or manually so that wrinkles, bent edges, or both do not occur on the paper when printing at the temperature and humidity. For example, Fig. 12 shows that when paper of the paper type in tray 1 was printed in the past at a temperature of 32.0°C and a humidity of 84.2%, wrinkles, bent edges, or both occurred on the paper, so the fixing temperature was changed to 175°C as a fixing condition and the XX roller speed was changed by -5% as a transport condition.

[0063] 11, the above information 1101 to 1103 is displayed, and the user can select whether or not to change the above transport conditions and fixing conditions by pressing either the "Yes" or "No" button. However, on this screen, together with this information, as shown in FIG. 12, fixing conditions and transport conditions that have been changed automatically or manually so that wrinkles, bent edges, or both do not occur on the paper when printed at the temperature and humidity may be displayed.

[0064] 11 and 12, the user can check this information displayed by image control unit 100 on operation unit 140, so that the user can know that there is a possibility that wrinkles or bent edges will occur in the paper the user is about to print on under the current environment, and by changing the displayed fixing conditions and transport conditions, the user can prevent wrinkles or bent edges from occurring in the paper the user is about to print on. In the above example, the paper type to be printed is the same, but when similar paper types (e.g., two thin papers) such as paper with similar material or containing a common material are set, the screens shown in Figs. 11 and 12 may be displayed.

[0065] Thus, in this embodiment, a reading unit (e.g., reading device 20) that reads the image of the medium being conveyed and an image control unit (e.g., image enlargement control unit 100) that determines whether the medium has wrinkles and bent edges based on whether multiple positions on the image of the medium read by the reading unit satisfy a predetermined relationship (e.g., each equation shown in Figures 7 and 8), and the image control unit 100 determines whether the medium has wrinkles based on the above-mentioned predetermined relationship, and then determines whether the medium has bent edges. Therefore, when an abnormality occurs, it is possible to distinguish whether an edge has been bent or whether a wrinkle has been generated. Conventionally, only one of bent edges and wrinkles could be detected, but it is possible to detect both simultaneously and distinguish between bent edges and wrinkles as described above. In addition, it is possible to prevent erroneous determination that an edge has been bent when only wrinkles have occurred, so that defects can be detected more accurately.

[0066] The device also has an operation unit (e.g., operation unit 140) that can select a first mode for determining whether the medium has wrinkles (e.g., mode 901 for determining only whether there are wrinkles) and a second mode for determining whether the medium has wrinkles and bent edges (mode 902 for determining both wrinkles and bent edges). If the medium, which is a printed matter, is intended to be cut, the bent edges are not a major problem as they are cut off. On the other hand, wrinkles remain as they are and therefore are a problem. In this way, the determination mode can be switched depending on how the medium is handled after printing.

[0067] 9, the image control unit changes the destination of the medium depending on whether the medium is determined to have wrinkles or bent edges. By changing the destination in this way, the user can easily find the paper determined to have a defect when visually determining the degree of the defect.

[0068] As described in FIG. 10, the image control unit changes the medium transport conditions and / or medium fixing conditions for each type of medium depending on whether the medium is wrinkled, whether the medium is folded, or whether the medium is both wrinkled and folded. This type of control can prevent the same phenomenon from occurring in subsequent printing operations. Several patterns of these conditions can be stored in advance, and a selection can be made from among them. For example, it is possible to control the rotation speed of a specific roller to be slowed down when an edge is folded.

[0069] 11 and 12, the image inspection device has a detection unit (e.g., a sensor not shown) that measures environmental conditions including temperature and / or humidity around the image inspection device, and the image control unit, for each type of medium, when it determines that the medium is wrinkled, when it determines that the medium has folded edges, and when it determines that the medium has both wrinkles and folded edges, associates the environmental conditions with printing conditions including the medium transport conditions and / or medium fixing conditions that have been changed by the user so that none of the conditions occurs, and records them in a memory or the like, and if the environmental conditions when the same type of medium is next printed are close to the environmental conditions recorded above to a certain extent, the user is notified that at least wrinkles or folded edges may occur on the medium. Therefore, the user can know in advance that there is a possibility that wrinkles, folded edges, or both may occur if printing is performed under the current environment, and as a result, can take measures such as canceling printing.

[0070] The image control unit also notifies the user of the possibility of wrinkles or bent edges, and presents printing conditions that have been changed so that either wrinkles or bent edges will not occur, which are recorded in association with the environmental conditions that are close to the certain level. In this way, by including environmental conditions as well as paper type as parameters, it is possible to prevent paper from being printed under conditions that are likely to cause bent edges or wrinkles, while taking into account daily environmental fluctuations. The user can also select whether or not to reflect the settings that prevent wrinkles or bent edges from occurring as printing conditions when printing next or later. [Explanation of symbols]

[0071] 1. Image forming system 10 Image forming device 20 Reading device 30 Aftertreatment device 40 Paper feeder 100 Image control unit 140 Operation section [Prior art documents] [Patent documents]

[0072] [Patent Document 1] Japanese Patent Application Publication No. 09-270908 [Patent Document 2] JP 2019-102824 A

Claims

1. A reading unit that reads an image on the medium being conveyed; and an image control unit that determines whether or not the medium has wrinkles and bent edges based on whether a plurality of positions on the image of the medium read by the reading unit satisfy a predetermined relationship, the image control unit determines whether or not the medium has wrinkles based on the predetermined relationship, and then determines whether or not the medium has bent edges, calculates a distance between edges of the medium as the predetermined relationship, and determines whether or not the medium has wrinkles based on the distance.

1. An image inspection device comprising:

2. An operation unit is provided. A first mode for determining whether the medium has wrinkles and a second mode for determining whether the medium has wrinkles and bent edges are selectable by the operation unit.

2. The image inspection apparatus according to claim 1 .

3. the image control unit changes the discharge destination of the medium depending on whether the medium is wrinkled or whether the medium is folded.

2. The image inspection apparatus according to claim 1 .

4. the image control unit changes, for each type of medium, a transport condition for the medium and / or a fixing condition for the medium depending on whether the medium is wrinkled, whether the medium is bent at an edge, or whether the medium is wrinkled and bent at an edge.

2. The image inspection apparatus according to claim 1 .

5. A detection unit that measures environmental conditions including temperature and / or humidity around the image inspection device, the image control unit, for each type of medium, when it determines that the medium has wrinkles, when it determines that the medium has bent edges, or when it determines that the medium has both wrinkles and bent edges, records the environmental conditions in association with printing conditions including the medium transport conditions and / or the medium fixing conditions that have been changed by the user so that any of the conditions do not occur, and when the environmental conditions when the same type of medium is next printed are closer to the environmental conditions at the time of the recording to a certain extent or more, notifies the user that there is a possibility that at least wrinkles or bent edges will occur in the medium.

2. The image inspection apparatus according to claim 1 .

6. the image control unit presents to a user a message indicating that the wrinkles or bent edges may occur, and the printing conditions recorded in association with the environmental conditions that are similar to the predetermined level or more, the printing conditions being changed so that the wrinkles or bent edges do not occur.

6. An image inspection apparatus according to claim 5.

7. A calculation unit is further provided which calculates an increment of an X coordinate and an increment of a Y coordinate of an edge of the medium between a predetermined line of the medium and a line that is an arbitrary number of lines away from the predetermined line, The image control unit determines whether the edge of the medium is folded based on the increment of the X coordinate and the increment of the Y coordinate.

2. The image inspection apparatus according to claim 1 .

8. An image forming apparatus comprising the image inspection device according to any one of claims 1 to 7.

Images