JP6308046B2 - Cut paper conveyance failure detection system - Google Patents

Description

  The present invention relates to a technique for detecting a conveyance failure of a cut sheet generated in a digital printing machine that prints the cut sheet.

  Since a digital printing machine that prints cut sheets transports cut sheets one by one, misalignment of the cut sheets occurs while the cut sheets are being transported from the paper feed unit to the fixing unit. Cut sheet misalignment occurs, for example, when the paper feed roller of the paper feed unit cannot grip the paper with uniform force, or when the roller installed in the transport path is worn down and cannot transmit the force. However, especially in a large-sized printer having a long cut paper conveyance path and a digital printing machine that conveys the cut paper at a high speed, the positional deviation of the cut paper occurs remarkably.

  If a misalignment occurs in the cut sheet fed to the fixing unit, the pattern is not printed at the predetermined position on the cut sheet. Therefore, even if a misalignment occurs in the cut sheet fed to the fixing unit, the pattern is placed at a predetermined position on the cut sheet. A printable invention has already been disclosed.

  For example, in Patent Document 1, a light emitting element array and a light receiving element array are arranged on a conveyance path between a paper feeding unit (hopper) that stores cut paper and a fixing unit (photosensitive drum) that forms an electrostatic latent image. It is arranged so that the positional deviation in the conveyance direction and the width direction of the cut sheet fed from the paper feeding unit is detected by the light receiving element array, and the fixing is performed based on the positional deviation in the conveyance direction and the width direction of the cut sheet. An invention for adjusting the position of an electrostatic latent image formed on a unit is disclosed. Further, Patent Document 2 discloses an invention in which the positional deviation in the oblique direction of the cut sheet can be adjusted in addition to the positional deviation in the conveyance direction and the width direction of the cut sheet. Further, Patent Document 3 discloses an invention that can reduce the number of elements in the issuing element array and the light receiving element array.

JP-A-5-210285 JP-A-9-150546 JP 2003-122227 A

  However, in large printers and high-speed printers with long cut paper transport paths, misalignment of cut paper tends to occur during transport from the paper feed unit to the fixing unit rather than when it is fed from the paper feed unit. . In order to cope with the misalignment that occurred during the conveyance from the paper feed unit to the fixing unit, if the light receiving element that detects the misalignment of the cut sheet is brought close to the fixing unit, the static adjustment is performed based on the misalignment of the cut sheet. The process of forming the electrostatic latent image on the fixing unit is not in time.

  Therefore, if an electrostatic latent image that has been adjusted based on the misalignment of the cut sheet cannot be formed on the fixing unit, such as a large printer or a high-speed printer, the cut sheet with the misalignment exceeding the allowable value is identified after printing. Therefore, it is necessary to prevent the outflow of defective products.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a system capable of detecting a positional deviation of a cut sheet to be printed by a fixing unit of a digital printing machine and identifying a cut sheet in which a positional deviation exceeding an allowable value has occurred after printing. .

  The first invention that solves the above-mentioned problems is an edge sensor that detects the edge position of a cut sheet that projects parallel light and feeds it to a fixing unit of a digital printing machine, and is discharged from the fixing unit of the digital printing machine The code scanner that optically reads the management code printed on the cut sheet and the edge position of the cut sheet are acquired from the edge sensor at the timing when the cut sheet is fed to the fixing unit of the digital printing machine, and the edge of the cut sheet When the positional deviation of the cut sheet calculated from the position exceeds the allowable value, it is determined that a conveyance failure has occurred, and at least the management code read by the code scanner from the cut sheet whose positional deviation exceeds the allowable value is stored. A cut sheet conveyance defect detection system comprising at least a control device.

  According to the first aspect of the present invention, the edge position of the cut sheet fed to the fixing unit of the digital printing machine is detected by the edge sensor, thereby calculating the positional deviation generated in the cut sheet fed to the fixing unit of the digital printing machine. it can. In addition, the management code printed on the cut sheet after printing discharged from the fixing unit of the digital printing machine is read by the code scanner, and the management code of the cut sheet in which the positional deviation exceeding the allowable value occurs is stored. , It is possible to specify a cut sheet in which a positional deviation exceeding the allowable value has occurred after printing.

  Further, the second invention is the cut sheet conveyance failure detection system described in the first invention, wherein the edge sensor for detecting the edge position of the trailing edge of the cut sheet fed to the fixing unit of the digital printing machine, The edge sensor for detecting the side edge of the cut sheet is arranged, and the control device calculates a positional deviation of the cut sheet in the transport direction from the edge position of the rear end of the cut sheet, and the edge position of the side edge of the cut sheet The positional deviation of the cut sheet in the width direction is calculated from the above. The second invention is an invention in which the positional deviation of the cut sheet in the transport direction and the width direction can be calculated.

  Furthermore, in the third aspect of the invention, the edge sensors for detecting the edge position of the trailing edge of the cut sheet are arranged on the left and right sides of the trailing edge of the cutting sheet, and the positional deviation in the oblique direction is detected from the difference between the left and right edge positions of the trailing edge. It is characterized by calculating. According to a third aspect of the present invention, the positional deviation of the cut sheet in the oblique direction can be calculated in addition to the transport direction and the width direction.

  According to the present invention described above, a misalignment occurring in the cut sheet during the conveyance from the paper feeding unit to the fixing unit of the digital printing machine is detected, and the cut sheet in which the misalignment exceeding the allowable value is detected is specified after printing. Can be provided.

The figure explaining the conveyance failure detection system of a cut sheet. The figure explaining an edge sensor. The figure explaining arrangement | positioning of an edge sensor. The figure explaining the relationship between the positional deviation of a cut sheet, and the edge position of a cut sheet. The figure explaining operation | movement of a control apparatus.

  From here, preferred embodiments of the present invention will be described. The following description is not intended to limit the scope of the present invention, but is provided to aid understanding.

  A cut sheet conveyance defect detection system 1 will be described with reference to FIG. As shown in FIG. 1, the cut sheet conveyance failure detection system 1 is a system provided in the digital printing machine 3 that prints the cut sheet 2, and projects parallel light 113 to fix the fixing unit 30 of the digital printing machine 3. An edge sensor 11 for detecting the edge position of the cut sheet 2 fed to the printer, and a management code 20 printed in the form of an optical recognition code on the printed cut sheet 2 discharged from the fixing unit 30 of the digital printing machine 3. A code scanner 12, an edge sensor 11, and a code scanner 12 are connected to each other, and at least from the control device 10 that calculates the positional deviation of the cut sheet 2 from the edge position of the cut sheet 2 and determines the occurrence of a conveyance failure. Composed.

  1, in addition to these, a control device 10 for controlling the digital printing machine 3 and a personal printer 13 serving as a device for outputting a detection result of the conveyance failure of the cut sheet 2 are illustrated, and the dental printing machine shown in FIG. 3 includes a sensor 31 for detecting the leading edge of the cut sheet 2 fed to the fixing unit 30 as a means for measuring the timing for detecting the edge position of the cut sheet 2, and further the timing for optically reading the management code 20 Is provided with a sensor 32 for detecting the leading edge of the cut sheet 2 discharged from the fixing unit 30.

  The edge sensor 11 will be described with reference to FIG. The edge sensor 11 according to the present embodiment includes a light projecting unit 110 that projects parallel light 113, a light receiving unit 111 that receives the parallel light 113 projected by the light projecting unit 110, and an edge position from the output of the light receiving unit 111. A commercially available transmissive laser sensor that includes at least a controller unit 112 that detects the above can be used as the edge sensor 11.

  The light projecting unit 110 of the edge sensor 11 includes a light source 110a that emits monochromatic light (for example, a red laser) and a lens 110b that converts the monochromatic light emitted by the light source 110a into a strip-shaped parallel light 113. The edge sensor 11 includes: The parallel light 113 projected by the light projecting unit 110 is installed so as to be shielded by the cut paper 2. The light receiving unit 111 of the edge sensor 11 includes a linear image sensor 111b in which light receiving elements are arranged in a row, and a lens 111a that condenses the parallel light 113 that has reached the light receiving unit 111 on the linear image sensor 111b. The controller unit 112 of the edge sensor 11 acquires the signal waveform output from the linear image sensor 111b at a predetermined sampling interval, and determines the length from the end of the measurement range to the edge of the cut sheet 2, that is, the cut sheet 2 The length in which the parallel light 113 is shielded is calculated as the edge position.

  The arrangement of the edge sensor 11 will be described with reference to FIG. As shown in FIG. 3, in the cut sheet conveyance defect detection system 1 according to the present embodiment, two edges for detecting the edge position of the trailing edge 2 a of the cut sheet 2 fed to the fixing unit 30 of the digital printing machine 3. A total of four edge sensors 11, which are a sensor 11 a and two edge sensors 11 b that detect the edge position of the side edge 2 b of the cut sheet 2 fed to the fixing unit 30 of the digital printing machine 3, are arranged.

  The parallel light 113 of the edge sensor 11 a that detects the edge position of the trailing edge 2 a of the cut sheet 2 fed to the fixing unit 30 of the digital printing machine 3 is parallel to the conveyance direction of the cut sheet 2. Then, one of the two edge sensors 11a for detecting the edge position of the rear end 2a of the cut sheet 2 is arranged at a position for detecting the edge position of the left rear end 2a, and the other one is the right rear end. It is arranged at a position for detecting the edge position 2a.

  Further, the parallel light 113 of the edge sensor 11b that detects the edge position of the side edge 2b of the cut sheet 2 fed to the fixing unit 30 of the digital printing machine 3 is perpendicular to the conveyance direction of the cut sheet 2. Although there may be only one edge sensor 11b that detects the edge position of the side edge 2b, in this embodiment, the edge position of the side edge 2b of the cut sheet 2 is also measured so that the length in the width direction of the cut sheet 2 can also be measured. One of the two edge sensors 11b for detecting the position is disposed at a position for detecting the edge position of the left side edge 2b, and the other is disposed at a position for detecting the edge position of the right side edge 2b. .

  The relationship between the positional deviation of the cut sheet 2 and the edge position of the cut sheet 2 will be described with reference to FIG. FIG. 4A is a view when the cut sheet 2 is not misaligned. When no positional deviation occurs in the cut paper 2, the edge position of the cut paper 2 detected by each edge sensor 11 is the center P0 of the measurement range.

  FIG. 4B is a diagram when the positional deviation in the transport direction occurs in the cut sheet 2. When advancement or delay occurs in the conveyance of the cut sheet 2 and the positional deviation in the conveyance direction occurs in the cut sheet 2, the edge position of the trailing edge 2a detected by the edge sensor 11a deviates from the center P0 of the measurement range, and the edge sensor 11b The edge position of the side edge 2b to be detected does not deviate from the center P0 of the measurement range. Therefore, the difference between the edge position of the rear end 2a and the center P0 of the measurement range can be used as the positional deviation in the transport direction.

  FIG. 4C is a diagram when the positional deviation in the width direction occurs in the cut sheet 2. When the cut sheet 2 is shifted to the right or left, if the position deviation in the width direction occurs in the cut sheet 2, the edge position of the side edge 2b detected by the edge sensor 11b is shifted from the center P0 of the measurement range, and the edge sensor 11a The edge position of the rear end 2a detected by is not deviated from the center position P0 of the measurement range. Therefore, the difference between the edge position of the side edge 2b and the center P0 of the measurement range can be used as a positional deviation in the width direction.

  FIG. 4D is a diagram when the positional deviation in the oblique direction occurs in the cut sheet 2. When the cut sheet 2 is obliquely shifted and the cut sheet 2 is displaced in the oblique direction, the edge position of the trailing edge 2a detected by the edge sensor 11a is deviated from the center P0 of the measurement range. The amount of left and right shifts is different. Therefore, the difference between the edge position of the right rear end 2a and the edge position of the left rear end 2a can be used as a positional deviation in the oblique direction.

  As described above, when the positional deviation occurs in the cut paper 2, the edge position detected by each edge sensor 11 varies according to the positional deviation generated in the cut paper 2, and therefore, from the edge position detected by each edge sensor 11. The positional deviation occurring on the cut paper 2 can be calculated.

  The code scanner 12 is an apparatus including an illumination component (such as an LED light source), an optical component (such as an optical lens), and an image sensor (such as a CCD sensor). When the code scanner 12 receives an instruction for reading the optical recognition code from an external device, the code scanner 12 analyzes the image taken using the image sensor and outputs the result of reading the optical recognition code (in this case, the management code 20). Output. Note that such a code scanner 12 can use a commercially available product corresponding to a one-dimensional barcode, a two-dimensional barcode, and an OCR (Optical Character Reader) character as an optical recognition code.

  Next, the control device 10 will be described. The control device 10 is a device realized by a general-purpose personal computer. In this embodiment, as shown in FIG. 1, the control device 10 is connected to a control panel 33 of the digital printing machine 3 and each edge sensor 11, and further outputs a detection result of conveyance failure of the cut sheet 2. A printer 13 is connected.

  The operation of the control device 10 will be described with reference to FIG. When a signal indicating the timing for detecting the edge position of the cut sheet 2 fed to the fixing unit 30 is input from the control panel 33 of the digital printing machine 3 to the control device 10 (S1), the control device 10 detects each edge sensor. The edge position detected by 11 is acquired from the controller unit 12 of the edge sensor 11 (S22). In the present embodiment, as a signal indicating the timing for detecting the edge position of the cut sheet 2, the signal of the sensor 31 that detects the leading end of the cut sheet 2 fed to the fixing unit 30 is used.

  Next, the control device 10 calculates the positional deviation of the cut sheet 2 using the edge position acquired from each edge sensor 11 (S3). As described above, in the present embodiment, since the positional deviation in the transport direction, the width direction, and the diagonal direction can be calculated, the control device 10 calculates the positional deviation in the transport direction, the width direction, and the diagonal direction. .

  Next, the control device 10 determines a conveyance failure (S4). In order to determine whether or not there is a conveyance failure, an allowable value of the positional deviation of the cut sheet 2 is registered in the control device 10, and the control apparatus 10 detects the positional deviation of the cut sheet 2 calculated from the edge position of the cut sheet 2. If the allowable value is exceeded, it is determined that a conveyance failure has occurred. In the present embodiment, since the control device 10 calculates the positional deviation in the transport direction, the width direction, and the oblique direction, an allowable value of the positional deviation is registered in the control device 10 for each of the transport direction, the width direction, and the oblique direction. The control device 10 determines that a conveyance failure has occurred when the positional deviation of the cut sheet 2 exceeds an allowable value in at least one of the conveyance direction, the width direction, and the oblique direction.

  The cut sheet 2 detected by the sensor 31 installed on the feed side of the fixing unit 30 is printed by the fixing unit 30 and detected by the sensor 32 installed on the discharge side of the fixing unit 30 to read the management code 20. When a signal indicating the timing is input (S5), the control device 10 transmits an instruction to read the management code 20 printed on the cut paper 2 by the fixing unit 30 to the code scanner 12, and the fixing unit 30 applies the cut paper 2 to the cut paper 2. The printed management code 20 is acquired from the code scanner 12 (S6).

  Next, the control device 10 confirms whether the cut sheet 2 from which the management code 20 has been read is the cut sheet 2 that has been determined to be a conveyance failure (S7). Whether the cut sheet 2 from which the management code 20 has been read is the cut sheet 2 that has been determined to be poorly transported is determined by a sensor 31 that detects the leading end of the cut sheet 2 fed to the fixing unit 30. From this, it can be determined using the number of cut sheets 2 existing in the conveyance path to the place where the sensor 32 for detecting the leading end of the cut sheet 2 discharged from the fixing unit 30 is arranged.

  Next, in the case of the cut sheet 2 determined as a conveyance failure, the control device 10 stores the management code 20 read by the code scanner 12 from the cut sheet 2 determined as a conveyance failure in a storage device connected to the control device 10. Thereafter, this management code 20 is output to the personal printer 13 (S8), and this procedure is terminated. Note that the information stored in the storage device connected to the control device 10 need not be only the management code 20, but other than the management code 20, the edge position detected by each edge sensor 11 from the cut sheet 2 determined to be a conveyance failure. Alternatively, a displacement calculated from the edge position detected by each edge sensor 11 may be included. Further, the control device 10 ends this procedure without recording or outputting the management code 20 in the case of the cut sheet 2 that has not been determined to be a conveyance failure.

  As described above, according to the cut sheet conveyance failure detection system 1 described above, the edge position of the cut sheet 2 fed to the fixing unit 30 of the digital printing machine 3 is detected by the edge sensor 11. The positional deviation generated on the cut sheet 2 fed to the fixing unit 30 can be calculated. Also, the management code 20 printed on the cut sheet 2 after printing discharged from the fixing unit 30 of the digital printing machine 3 is read by the code scanner 12, and the management of the cut sheet 2 in which the positional deviation exceeding the allowable value has occurred is performed. By storing the code 20, the cut sheet 2 in which the positional deviation exceeding the allowable value has occurred can be specified after printing.

DESCRIPTION OF SYMBOLS 1 Cut sheet conveyance defect detection system 10 Control apparatus 11 Edge sensor 113 Parallel light 12 Code scanner 13 Printer 2 Cut sheet 2a Rear end 2b Side end 20 Management code 3 Digital printing machine 30 Fixing unit 31 Cut sheet feed to fixing unit Sensor for detecting the leading edge 32 Sensor for detecting the leading edge of the cut sheet discharged from the fixing unit

Claims (3)

  Optically outputs an edge sensor that detects the edge position of cut paper that projects parallel light and feeds it to the fixing unit of the digital printing machine, and a management code printed on the cut paper discharged from the fixing unit of the digital printing machine The edge position of the cut sheet is acquired from the edge sensor at the timing when the cut sheet is fed to the fixing unit of the digital printing machine, and the deviation of the cut sheet calculated from the edge position of the cut sheet is an allowable value. A control device that at least stores a management code read by the code scanner from a cut sheet whose positional deviation has exceeded an allowable value. A cut sheet conveyance failure detection system.   The edge sensor that detects the edge position of the trailing edge of the cut sheet that is fed to the fixing unit of the digital printing machine and the edge sensor that detects the side edge of the cut sheet are arranged, and the control device includes a rear edge of the cut sheet. The position deviation of the cut sheet in the conveyance direction is calculated from the edge position of the edge, and the position deviation of the cut sheet in the width direction is calculated from the edge position of the side edge of the cut sheet. Cut paper conveyance failure detection system. The edge sensors for detecting the edge position of the trailing edge of the cut sheet are arranged on the left and right sides of the trailing edge of the cut sheet, and the positional deviation in the oblique direction is calculated from the difference between the left and right edge positions of the trailing edge. The cut sheet conveyance defect detection system according to claim 2.

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