JP4853440B2 - Printing system - Google Patents

Description

  The present invention relates to a printing system.

  Japanese Patent Application Laid-Open No. 2004-151561 discloses a multiple print system that performs multiple continuous printing. This multi-continuous printing system includes, for example, a first high-speed page printer that prints on the surface of continuous paper, and a second high-speed page printer that prints on the back side of continuous paper after printing on the front surface by the first high-speed page printer. Yes.

  In this multi-continuous printing system, when a continuous paper jam occurs in the second high-speed page printer, the printing operations of the first and second high-speed page printers are stopped. In this case, the continuous paper that has been printed on the front surface by the first high-speed page printer remains between the first high-speed page printer and the second high-speed page printer.

  Thereafter, when the occurrence of the jam is resolved and the operation of the multi-continuous printing system is resumed, the print resuming page in the second high-speed page printer from the continuous paper remaining between the first high-speed page printer and the second high-speed page printer. To decide.

Therefore, even when a jam occurs in the second high-speed page printer, it is not necessary to remove the continuous paper remaining between the first high-speed page printer and the second high-speed page printer, and the operation of the multi-layer printing system is not necessary. Loss of the continuous paper remaining due to the stop can be suppressed.
JP 2003-39750 A

  In the printing system, when a printing paper jam occurs, the operation of the printing system is generally temporarily stopped, the jammed paper is removed, and the operation is resumed. However, when the paper is a continuous paper, a large amount of paper is lost in the paper transport path in the printing system, so the loss is not small. In particular, when the printing system is a multiple printing system in which multiple printing devices are connected in series, or when the printing system is a tandem type used in an electrophotographic system, the paper transport path is long. A large amount of waste paper is also generated.

  On the other hand, with the system disclosed in Patent Document 1, even when a jam occurs in the second high-speed page printer, the continuous remaining between the first high-speed page printer and the second high-speed page printer. It is not necessary to remove the paper, and loss of continuous paper can be suppressed.

  However, even in the technique disclosed in Patent Document 1, since the system operation is stopped when a print paper jam occurs, printing is not performed while the operation is stopped. There is a problem that it ends up.

  In the technique disclosed in Patent Document 1, since both the first high-speed page printer and the second high-speed page printer are configured by a single printer engine using a single photosensitive drum, printing is performed by the first high-speed page printer. It is easy to determine the print restart page in the second high-speed page printer from the finished page. However, in a printing system in which a plurality of tandem printing apparatuses are connected in cascade, it is difficult to resume printing from the position where the operation was stopped due to the occurrence of a paper jam. In other words, since the printing apparatus is a tandem type, a plurality of pages can be printed simultaneously by a plurality of linter engines before and after the continuous paper flow in a series of paper conveyance paths, so that a certain page has been printed. This is because the operation cannot be stopped at the stage.

  Further, since a paper transport path is long in a tandem type printing apparatus, if a paper is not nipped by a roller pair at various points in the paper transport path, operation is caused by the occurrence of paper jam as in the technique of Patent Document 1. When the printing is resumed from the position where the printing is stopped, the behavior of the paper whose conveyance has been resumed is not stable for a while, so it is difficult to resume the printing immediately from the position where the operation is stopped in a sufficient printing state.

  In other words, due to these difficulties, it is actually difficult for the technique of Patent Document 1 to suppress the occurrence of paper loss such as continuous paper in various types of printing apparatuses such as a tandem type electrophotographic printing apparatus. There is a problem of being.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a printing system that can suppress loss of a printing medium such as continuous paper and can prevent a reduction in productivity of printing processing.

  (1) The present invention includes a supply device that supplies a continuous print medium, and a printing device that prints a unit image on the print medium supplied from the supply device. A conveyance path that conveys the supplied print medium; and a printer engine that performs printing on the print medium on the conveyance path, and abnormality in image formation by the printer engine and the print medium in the conveyance path An abnormality detecting means for detecting the presence or absence and the degree of at least one of the abnormalities in the conveyance of the image, an abnormality in image formation by the printer engine detected by the abnormality detection means, or an abnormality in the conveyance of the print medium in the conveyance path Is determined to be greater than a first preset level, printing by the printing apparatus is stopped and the printer engine is turned off. When it is determined that the degree of abnormality in image formation or the abnormality in conveyance of the print medium in the conveyance path is smaller than the first degree and larger than a preset second degree and smaller than the first degree. Is a printing system comprising a printing control means for continuing printing by the printing apparatus.

  (2) In the invention of (1), the print control means is configured such that the degree of abnormality in image formation by the printer engine or the abnormality in conveyance of the print medium in the conveyance path is greater than the second degree and the first After the printing apparatus determines that the printing apparatus is smaller than the predetermined level and continues printing by the printing apparatus, a predetermined number of the abnormalities of the image formation or the abnormalities of the conveyance of the printing medium in the conveyance path are not smaller than the second degree. When the unit image is printed, printing by the printing apparatus may be stopped.

(3) In the invention of (1) or (2), a plurality of the printing apparatuses are provided, and the plurality of printing apparatuses are connected in cascade with each other, and the printing medium supplied from the supply apparatus The unit images are continuously printed on the printing medium by sharing the different portions of the unit image with each other and performing the continuous printing of the unit images, and the printing apparatuses print images of different colors. A plurality of the printer engines are provided, and color images are printed by superimposing and forming images of different colors printed by the plurality of printer engines on the print medium,
The abnormality detecting means detects whether or not there is an abnormality in image formation by the printer engine and the degree thereof, and whether or not there is a positional deviation between different color images printed by a plurality of printer engines of the printing apparatus. You may make it further provide a position shift detection means.

  (4) In the invention according to any one of (1) to (3), the abnormality detecting means may detect whether there is an abnormality in the conveyance of the print medium in the conveyance path and the extent thereof, and the width direction of the print medium in the conveyance path. A printing medium position deviation detecting means for detecting the presence or absence and the degree of the deviation may be further provided.

(5) In any one of the inventions of (1) to (3), the abnormality detecting unit further includes an image misregistration detecting unit, and the image misregistration detecting unit is placed on the print medium by each printer engine. The first inspection image forming means for forming a first inspection image at a predetermined timing and the first inspection image formed by the inspection image forming means on the print medium are stored on the print medium. A first inspection image reading unit that reads in the length direction and a first interval that detects the interval between the first inspection images formed by the printer engines read by the first inspection image reading unit. Displacement between the images of different colors printed by the respective printer engines according to the intervals of the first inspection images detected by the first inspection image interval detection means and the first inspection image interval detection means And a first inspection image determination unit that determines the presence and absence and the degree thereof.

  (6) In the invention described in (5), the first inspection image forming unit may have the length direction of the print medium as the first inspection image on the print medium by each printer engine. An image that is the width direction and an image in which the length direction forms an acute angle with the width direction of the print medium are formed, and the first inspection image interval detection unit is configured such that the length direction is the width direction of the print medium. Detecting an interval between the first inspection images for each of the first inspection image and the first inspection image whose length direction forms an acute angle with the width direction of the print medium, The first inspection image determination unit is configured to print the image between images of different colors that are printed by the printer engines according to the interval of the first inspection image whose length direction is the width direction of the print medium. There is misalignment in the length direction of the medium. The print medium between the images of different colors printed by the respective printer engines according to the interval of the first inspection images whose length direction forms an acute angle with the width direction of the print medium. The presence / absence and the degree of positional deviation in the width direction may be determined.

(7) In the invention described in (4), the print medium misregistration detection means may be configured so that the two sides facing each other on the print medium by any one of the printer engines face each other in the width direction of the print medium. A rectangular image whose two sides are the length direction of the print medium, and a blank on a line whose length direction forms an acute angle with the width direction of the print medium intersects the center of the image. A second inspection image forming unit that forms a second inspection image, and a second inspection image formed by the inspection image forming unit on the print medium is read in a length direction of the print medium. Second inspection image reading means, and second inspection image interval detection means for detecting the interval between the front and rear portions of the blank of the second inspection image read by the second inspection image reading means. And for the second inspection Second inspection image determination means for determining whether or not there is a displacement in the width direction of the print medium in the transport path by each interval of the second inspection image detected by the image interval detection means; Further, it may be provided.

  (8) In the invention described in (4), the print medium positional deviation detection means is provided at each of edge portions on both sides in the width direction of the print medium of the transport path, and the end in the width direction of the print medium. An edge portion detection means for detecting each edge portion; and detection of the edge portion by the edge portion detection means and a detection time in which the detection is continuously performed in the width direction of the print medium in the transport path. Detection time determination means for determining whether or not there is a deviation and its degree may be further provided.

  (9) In the invention of any one of (1) to (8), an abnormality in image formation by the printer engine or an error in the print medium in the transport path by the abnormality detection unit for each unit image after printing by the printing apparatus. Printing performed by the print control unit while it is determined that the degree of conveyance abnormality is smaller than the first degree and larger than the second degree, and printing is performed while the degree of abnormality is smaller than the second degree. Identifying means for discriminating between the unit images, cutting means for cutting the print medium for each unit image, and the printer engine for the print medium for each unit image after cutting by the cutting means by the printer engine. The degree of image formation abnormality due to printing or the conveyance abnormality of the print medium in the conveyance path is smaller than the first degree and larger than the second degree. And that the degree and the abnormal having been subjected to the printing by the Most remain determined the printing control means has been printed remain less than said second degree may be further provided with a separating means.

  (10) In the invention described in (9), the identification unit detects the abnormality that has been printed by the print control unit while detecting the abnormality of each unit image after printing by the printing apparatus. An identification mark forming means for forming an identification mark on the print medium for identifying what has been printed without printing, an identification mark reading means for reading the identification mark of the print medium, and each unit after printing by the printing apparatus Unit image identification for discriminating between the image printed by the printing control means while detecting the abnormality by the identification mark read by the identification mark reading means and the image printed without detecting the abnormality And a means.

(11) In the invention of (2), the abnormality detection means detects an abnormality in image formation by the printer engine or an abnormality in conveyance of the print medium in the conveyance path, and the degree of the abnormality is the first degree. The apparatus further comprises first counting means for counting the number of unit images that are continuously printed while being determined to be smaller and larger than the second degree, and the printing control means includes the first counting means. When the number of unit images to be counted exceeds a preset first value, printing by the printing apparatus may be stopped.

  (12) In the invention described in (11), the degree of abnormality detected by the abnormality detecting means is smaller than the second degree without the value counted by the first counting means exceeding the first value. When this happens, a numerical value clearing means for clearing the numerical value counted by the first counting means may be further provided.

(13) In the inventions of (1) to (12), the abnormality detection means detects an abnormality in image formation by the printer engine or an abnormality in conveyance of the print medium in the conveyance path, and the degree of the abnormality is The printing apparatus further comprises second counting means for counting the total number of the unit images printed while being determined to be smaller than the first degree and larger than the second degree, and the printing control means includes the printing device. When the ratio of the number of unit images counted by the second counting means to the total number of unit images to be printed by exceeds the preset second value, the printing device Printing may be canceled.

  (14) In the inventions of (1) to (13), further comprising print data supply means for supplying print data of each unit image to be printed on the print medium, wherein the printing apparatus is supplied by the print data supply means The print data of each unit image to be printed is sequentially printed on the print medium, and the print control means detects an abnormality in image formation by the printer engine or an abnormality in conveyance of the print medium in the conveyance path by the abnormality detection means. When detecting and determining that the degree of abnormality is smaller than the first degree and larger than the second degree and continuing printing by the printing apparatus, the degree of abnormality is smaller than the second degree. Until the abnormality is first detected, the print data of the unit image is continuously printed, and when the abnormality is resolved, it is before the first detection. From the print data of the unit image may be resumed printing of the unit image.

  According to the invention of (1), even if an abnormality in image formation by each printer engine or an abnormality in the print medium in the transport path occurs, the process waits for the abnormality to be resolved without stopping printing immediately. Since printing is stopped only when printing continues to some extent even if printing is not resolved, printing is interrupted in various types of printing devices such as tandem-type electrophotographic printing devices and transported to the printing system. It is possible to suppress the occurrence of a large amount of print medium loss in the path. Also, even if there is an abnormality in image formation by each printer engine or an abnormality in the conveyance of the print medium in the conveyance path, the printing is not immediately stopped, so that the productivity of the printing process that occurs by stopping the printing is reduced. Can be prevented.

  According to the invention of (2), after determining that the degree of image formation abnormality or the printing medium abnormality in the conveyance path is larger than the second degree and smaller than the first degree, printing by the printing apparatus is continued. Printing is interrupted when a predetermined number of unit images have been printed, and printing is continued when the degree of abnormalities in the conveyance of the print medium is less than the second level before reaching the predetermined number. Thus, it is possible to prevent a large amount of print medium from being lost in the conveyance path of the printing system. Also, even if there is an abnormality in image formation by each printer engine or an abnormality in the conveyance of the print medium in the conveyance path, the printing is not immediately stopped, so that the productivity of the printing process that occurs by stopping the printing is reduced. Can be prevented.

  According to the invention of (3), the presence / absence and degree of misregistration between images of different colors printed by a plurality of printer engines are detected, and printing is not stopped immediately even if some abnormality occurs. Therefore, it is possible to suppress the occurrence of a large amount of loss of the print medium in the conveyance path of the printing system by interrupting the printing. Also, even if there is an abnormality in image formation by each printer engine or an abnormality in the conveyance of the print medium in the conveyance path, the printing is not immediately stopped, so that the productivity of the printing process that occurs by stopping the printing is reduced. Can be prevented.

  According to the invention of (4), the presence / absence and extent of the deviation in the width direction of the print medium in the print medium conveyance path is detected, and printing is not immediately stopped even if the abnormality occurs to some extent. It is possible to suppress the occurrence of a large amount of loss of the print medium in the conveyance path of the printing system by being interrupted. Also, even if there is an abnormality in image formation by each printer engine or an abnormality in the conveyance of the print medium in the conveyance path, the printing is not immediately stopped, so that the productivity of the printing process that occurs by stopping the printing is reduced. Can be prevented.

  According to the invention of (5), it is possible to detect the presence / absence and degree of misalignment between images of different colors printed by a plurality of printer engines by printing the first inspection image.

  According to the invention of (6), it is detected whether or not there is a positional deviation in the width direction of the print medium between images of different colors printed by a plurality of printer engines by printing the first inspection image. Can do.

  According to the invention of (7), the presence / absence and the extent of the positional deviation in the width direction of the print medium between the images of different colors printed by a plurality of printer engines are detected by printing the second inspection image. Can do.

  According to the invention of (8), it is possible to detect whether or not there is a shift in the width direction of the print medium in the transport path of the print medium, and its degree.

  (9) According to the invention of (10), it is possible to easily distinguish between a normally printed print medium and a print medium printed with an abnormality.

  (11) According to the invention of (12), it is determined that the degree of abnormality in image formation or the abnormality in the print medium in the conveyance path is larger than the second degree and smaller than the first degree, and printing by the printing apparatus is continued. Printing is stopped when a predetermined number of unit images have been printed, and printing is continued when the degree of abnormality in the conveyance of the print medium becomes smaller than the second level by the time the predetermined number of unit images is printed. It is possible to suppress the occurrence of a large amount of loss of the print medium in the conveyance path of the printing system. Also, even if there is an abnormality in image formation by each printer engine or an abnormality in the conveyance of the print medium in the conveyance path, the printing is not immediately stopped, so that the productivity of the printing process that occurs by stopping the printing is reduced. Can be prevented.

  According to the invention of (13), even if printing is continued in a state where the degree of abnormality is smaller than the first degree and larger than the second degree, the total number of unit images printed in the abnormal state will be printed. Since the printing is stopped when it is larger than the total number of unit images, it is possible to suppress the occurrence of a large amount of loss of the print medium in the conveyance path of the printing system.

  According to the invention of (14), even if printing is continued in a state where the degree of abnormality is smaller than the first degree and larger than the second degree, the same unit image is continuously printed, and the degree of abnormality is higher than the second degree. Since printing starts from the unit image after the size becomes small, all unit images can be printed with almost no abnormality.

  Hereinafter, a plurality of examples of an embodiment of the present invention will be described with reference to the drawings.

[Embodiment 1]
FIG. 1 is an explanatory diagram showing the overall configuration of the printing system of the present embodiment. In this printing system 1, a plurality of printing apparatuses, in this example, two printing apparatuses, a front surface printing apparatus 2 and a back surface printing apparatus 3, are connected in cascade, and these two printing apparatuses perform multiple printing. It is a system that performs.

  First, the paper feeding device 4 (supply device) supplies a continuous print medium for printing to the front surface printing device 2. The printing medium in this example is specifically a continuous paper P, and the paper feeding device 4 stores the continuous paper P in a roll shape, and continuously feeds the continuous paper P to the printing system 1. Supply.

  Next, the front surface printing apparatus 2 and the back surface printing apparatus 3 will be described. The front surface printing device 2 and the back surface printing device 3 are connected in cascade. For the continuous paper P supplied from the paper feeding device 4, the front surface printing device 2 (first printing device) first prints, and then The back side printing device 3 (second printing device) located downstream of the front surface printing device 2 on the transport path of the continuous paper P performs printing on the continuous paper P after printing. The front surface printing device 2 and the back surface printing device 3 continuously print unit images on the same continuous paper P supplied by the paper feeding device 4. This unit image (printed image) is a form image in this example, and each form is continuously printed on the continuous paper P. In this case, the front surface printing apparatus 2 and the back surface printing apparatus 3 share different parts of the same form with each other and print the form on the continuous paper P in a continuous manner. Specifically, in this example, the printing system 1 is used for double-sided printing, and printing is performed by the front surface printing device 2 on one surface (front surface) of the continuous paper P supplied from the paper feeding device 4, and thereafter The back side printing device 3 performs the continuous printing for printing the other side (back side) of the continuous paper P, and the front side printing device 2 and the back side printing device 3 share the front and back printing.

  As described above, the front surface printing apparatus 2 and the back surface printing apparatus 3 continuously print a large number of forms on the continuous paper P. This form is, for example, an invoice, and the basic form is common to each form. However, the name or name and address of the destination of the invoice, the invoice items of the invoice, etc. are different for each form. The front and back surfaces of each form are continuously printed on the front and back surfaces of the continuous paper P. As a result, the continuous paper P after printing is in a state in which a large number of form papers C are printed, and in this state, post-processing is performed. Each form C is sent to the apparatus 6 and separated by the post-processing apparatus 6 as described later.

  The front / back reversing device 5 is provided on the conveyance path of the continuous paper P between the front surface printing device 2 and the back surface printing device 3, and reverses the front and back of the continuous paper P printed on the front surface by the front surface printing device 2. The printing device 3 is supplied so that the back surface printing device 3 can also print on the back surface of the continuous paper P.

  The post-processing device 6 performs necessary post-processing on the continuous paper P that has been printed by the front surface printing device 2 and the back surface printing device 3. In this example, processing is performed such that each form paper C constituting the continuous paper P is separated, and the separated form papers C are stacked.

  A sheet conveyance path 41 between the sheet feeding device 4 and the front surface printing apparatus 2, a sheet conveyance path 42 between the front surface printing apparatus 2 and the front / back reversing apparatus 5, and a sheet between the front / back reversing apparatus 5 and the back surface printing apparatus 3. In the conveyance path 43 and the sheet conveyance path 44 between the back surface printing apparatus 3 and the post-processing apparatus 6, in order to absorb fluctuations in the sheet distance between apparatuses due to a shift in the conveyance timing of the continuous sheet P, etc. A paper buffer for a prescribed amount of continuous paper P is provided. The specified amount of the paper buffer is determined so as not to reach the range limit of the paper buffer in consideration of the fluctuation of the continuous paper P transport amount due to the timing of transport of the continuous paper P between the apparatuses and the acceleration difference. Yes.

  Next, a detailed configuration of each apparatus constituting the printing system 1 will be described.

  FIG. 2 is an explanatory diagram showing a schematic configuration of the front surface printing apparatus 2 and the back surface printing apparatus 3. Since the front surface printing apparatus 2 and the back surface printing apparatus 3 have the same basic configuration, the front surface printing apparatus 2 will be described as a representative here.

  The surface printing apparatus 2 is a printing apparatus that forms a color image by electrophotography. In this example, the printing method is a multiple transfer tandem method. That is, an image of black (hereinafter simply referred to as “K”) is formed in the front surface printing apparatus 2 from the upstream side in the transport direction (arrow 11 direction) along the transport path 15 of the continuous paper P. Image station 12K, image station 12C that forms an image of cyan (hereinafter simply referred to as “C”), image station 12M that forms an image of magenta (hereinafter simply referred to as “M”), yellow (hereinafter referred to as “M”) Image stations 12Y that form an image of a color simply “Y” are sequentially arranged. By sequentially moving the image stations 12K, 12C, 12M, and 12Y through the conveyance path, toner images of K, C, M, and Y are sequentially superimposed on the continuous paper P, and thus are continuously formed. A color image is formed on the paper P.

  Each image station 12K, 12C, 12M, 12Y is provided with a printer engine for forming a toner image of each color. Since the configuration of the printer engine is common to the image stations 12K, 12C, 12M, and 12Y, here, the printer engine 13K of the image station 12K will be described as a representative.

  The printer engine 13K includes a photosensitive drum 21. The photosensitive drum 21 rotates counterclockwise in FIG. 2, and various known devices for forming an image by an electrophotographic process are provided around the photosensitive drum 21.

  First, the pre-charger 22 (charging device) performs a charging process for uniformly charging the surface of the photosensitive drum 21 to a constant potential. As the charging method, various methods such as a non-contact method such as corona discharge and a contact method such as a roller charging method can be used.

  The exposure device 23 optically writes an electrostatic latent image on the surface of the photosensitive drum 21 charged by the precharger 22. As a light source used for the exposure apparatus 23, a semiconductor laser, a gas laser, or the like can be used. When a semiconductor laser is used as the light source, generally, a known optical element (none of which is shown) such as a collimator lens, a polygon mirror, and an fθ lens is provided in the exposure device 23, and thereby the photosensitive drum 21. The surface is exposed and scanned.

  The developing device 24 performs a developing process for developing the electrostatic latent image on the surface of the photosensitive drum 21 with toner. In this example, the developing device 24 employs a two-component developing method, and toner used in the developing device 24 is supplied from a toner collector 25. In addition, a one-component development method, a wet development method, or the like may be used as the development method.

  The transfer charger 26 (transfer device) performs a transfer process of transferring the toner image formed on the surface of the photosensitive drum 21 onto the continuous paper P. As a transfer method, in addition to the corona transfer method, a roller transfer method, a belt transfer method, a pressure transfer method, an adhesive transfer method, and the like can be used. In this example, the transfer charger 26 is opposed to the highest position on the surface of the photosensitive drum 21 with the continuous paper P interposed therebetween. In the case of the surface printing apparatus 2, the surface on which the continuous paper P is printed is down. Then, the toner image is transferred to the surface, and in the case of the back surface printing device 3, the surface to be printed of the continuous paper P whose front and back surfaces are reversed by the front and back reversing device 5 is down and the toner image is transferred to the surface. In this example, a method for directly transferring the toner image on the photosensitive drum 21 onto the continuous paper P is illustrated. However, by interposing an image carrier such as an intermediate transfer belt in the middle, the photosensitive drum The toner image on 21 may be indirectly transferred to the continuous paper P.

  The transfer cleaner 27 (cleaning device) removes the toner remaining on the surface of the photosensitive drum 21 even after the transfer process. The toner removed by the transfer cleaner 27 is accommodated in the toner recovery bottle 29 via the toner recovery path 28. In this example, the common toner collection bottle 29 is used in the image stations 12K, 12C, 12M, and 12Y. However, a toner collection bottle may be prepared for each of the image stations 12K, 12C, 12M, and 12Y.

  The continuous paper P formed by sequentially superimposing the color toner images of K, C, M, and Y at each of the image stations 12K, 12C, 12M, and 12Y is positioned on the downstream side of the image station 12Y on the conveyance path 15. The image is fixed by the fixing device 30 (see FIG. 1). In the present embodiment, the fixing method used in the fixing process includes a flash method, a non-contact method other than the flash method, a contact method such as a heat roller method, and a pressure method such as a pressure roller method.

  As shown in FIG. 1, an alignment sensor 14 is provided at a position upstream of the image stations 12K, 12C, 12M, and 12Y in the paper conveyance path 15 of the back surface printing apparatus 3. That is, the front surface printing apparatus 2 prints a predetermined identification mark (print position determination mark) on a certain area outside the user print area of each form paper C constituting the continuous paper P. That is, this alignment mark is an identification mark for aligning the printing positions of the front and back surfaces of the same form C, and at a predetermined timing after the alignment sensor 14 detects the alignment mark. By sequentially printing the back side from the image stations 12K, 12C, 12M, and 12Y of the back side printing apparatus 3, the position of the image on the front side of the same form C and the position of the back side image are prevented from shifting.

  Further, the position of the image on the front side and the position of the back side image of the same form paper C is adjusted not by reading the print position determination mark by the alignment sensor 14 but by the transport distance of the continuous paper P. It may be. The transport distance of the continuous paper P can be determined from, for example, the number of rectangular wave pulses output from a roller sensor 106 described later with reference to FIG. That is, for example, when the printing on the front surface of the form paper C that is the front surface printing apparatus 2 is completed, the back surface of the form paper C is printed when the continuous paper P is conveyed by a predetermined distance by the back surface printing apparatus 3. Thus, the position of the image on the front surface and the position of the image on the back surface of the same form paper C can be prevented from shifting.

  FIG. 3 is a plan view (a) and a front view (b) of the front / back reversing device 5. The front / back reversing device 5 includes a cylindrical turn bar 31, a pair of support portions 32 that pivotally support both ends of the turn bar 31, and a base member 33 that serves as a pedestal to which the pair of support portions 32 are fixed. It has.

  The continuous paper P that has been printed on the front surface by the surface reversing device 2 is wound around the turn bar 31 so that the length direction of the continuous paper P has an inclination of approximately 45 degrees with respect to the axial direction of the turn bar 31. Sent out. As a result, the continuous paper P whose front side is the lower side when sent out from the front surface inversion device 2 is sent out to the back side printing device 3 with the back side facing down.

  FIG. 4 is an explanatory diagram of the post-processing device 6. In the continuous paper P sent out from the back surface printing device 3, the mark for determining the printing position is detected by the mark detection sensor 51. As a result, the position of each form paper C printed in duplicate by the front surface printing device 2 and the back surface printing device 3 can be determined. Therefore, based on the detection of the print position determination mark by the mark detection sensor 51, the continuous paper The position at which each form paper C in P is cut by the cutter 52 can be detected. That is, since the cutting position between the paper sheets C is at a predetermined distance in the length direction of the continuous paper P from the detection position of the printing position determination mark, the paper sheets C are cut at the detection timing of the printing position determination mark. The operation timing of the cutter 52 is determined.

  As described above, the print position determination mark is also used to synchronize the print positions of the front surface printing device 2 and the back surface printing device 3 as described above, and each form in the continuous paper P is processed by the post-processing device 6. Although it is also used for detecting the position at which the paper C is cut by the cutter 52, these target marks may be printed on the continuous paper P as separate marks. In this case, the mark used for detecting the position at which each form paper C in the continuous paper P is cut by the cutter 52 may be printed by the back surface printing device 3 (hereinafter, a print position determination mark). Thus, description will be made assuming that the position where each form paper C is cut by the cutter 52 is detected.

  Further, as will be described later, in printing by the front surface printing apparatus 2 or the back surface printing apparatus 3, even if there is an abnormality in image formation by each printer engine or an abnormality in paper conveyance in the paper conveyance path 15, a process of continuing printing as it is is performed. . In this case, the continuous paper P that has been printed with the abnormality is broken paper. Therefore, it is necessary to separate the form paper C that has become damaged paper from the form paper C on which the form has been correctly printed by the front surface printing apparatus 2 and the back surface printing apparatus 3. Therefore, the form paper C printed with abnormal image formation or paper conveyance and the form paper C on which the form is correctly printed are identified by a print defect identification mark to be described later.

  That is, when the printing defect identification mark serving as an identification mark is read by the mark detection sensor 51 and it is determined that the form C is printed with abnormal image formation or paper conveyance, the mark 52 is separated by the cutter 52. Each form paper C is sent to the purge device 53. Further, when it is determined that the form C is a form on which the form is correctly printed based on the print defect identification mark, it passes through the purge device 53 and is conveyed to the stacker 54. When the form paper C is fed into the purge device 53, the feed mechanism 54 is lowered (position 54a) and fed by the rotation of the paper feed roller 55 of the purge device 53. In this way, the form paper C sent to the purge device 53 and the form paper C conveyed to the stacker 54 are separated. When transporting the form paper C to the stacker 54, the form paper C is passed through the purge device 53 and transported to the stacker 54 with the feeding mechanism 54 pulled up (position 54b).

  In addition, in order to identify the form paper C that has become damaged paper and the form paper C on which the form has been correctly printed by the front surface printing apparatus 2 and the back surface printing apparatus 3, a print defect identification mark is detected by the mark detection sensor 51. Instead of reading, the determination may be made based on the paper conveyance distance of the continuous paper P. For example, a form paper C having an abnormality in image formation by each printer engine or an abnormality in paper conveyance in the paper conveyance path 15 is obtained by changing the continuous paper P to a predetermined length from the time when printing is finished by the front surface printing apparatus 2 or the rear surface printing apparatus 3. When the sheet is conveyed, it can be determined that the sheet is in a predetermined position on the sheet conveyance path in the post-processing device 6. The transport distance of the continuous paper P may be determined by providing a roller sensor 106 described later on the paper transport path in the post-processing device 6 or counting the elapsed time. It is also conceivable to determine the number of forms C processed by the post-processing device 6 from the number of times the cutter 52 is driven, and thus the transport distance of the continuous paper P.

  The paper conveyance rollers 56 and 57 before and after the cutter 52 in the conveyance path of the form paper C have a rotational speed difference so that the purge device 53 has the front and rear forms of the conveyance path after being cut by the cutter 52. Collisions between the papers C are prevented from occurring.

  In the stacker 54, a large number of form sheets C on which forms are correctly printed are stacked and stored. Since the stacker 54 detects the weight of the sheet and moves up and down, the stacker 54 gradually descends as the number of stacked forms C increases.

  FIG. 5 is an explanatory diagram of sensors provided in the front surface printing apparatus 2 and the back surface printing apparatus 3. This figure shows the sheet transport path 15 in a straight line, and shows the continuous sheet P and the image stations 12K, 12C, 12M, and 12Y on the sheet transport path 15 from the lower side. Since the front surface printing apparatus 2 and the back surface printing apparatus 3 have the same sensors as described here, the front surface printing apparatus 2 will be described below as a representative.

  The skew detection sensor 101, the registration mark laser sensor 102, the color registration mark laser sensor 104, and the like described here indicate whether or not there is an abnormality in the image formation in the printer engine or the abnormality in the conveyance of the continuous sheet P in the sheet conveyance path 15. It is to detect.

  First, a pair of skew detection sensors 101 are provided on the upstream side of the image station 12K on the paper conveyance path 15 of the continuous paper P of the front surface printing apparatus 2. Each of the skew detection sensors 101 is a transmissive optical sensor, and is disposed on both sides of the continuous paper P in the width direction. Each skew detection sensor 101 detects an edge portion of the continuous paper P in the width direction. That is, if the behavior of the continuous paper P conveyed during printing is normal, each skew detection sensor 101 does not detect the continuous paper P. However, when the continuous paper P conveyed during printing is displaced in the width direction, one of the skew detection sensors 101 detects the edge portion in the width direction of the continuous paper P displaced in the width direction.

  A registration mark laser sensor 102 is provided at a position downstream of the image station 12Y on the paper transport path 15 of the continuous paper P of the front surface printing apparatus 2. That is, the image station 12K prints the registration mark 103 in a certain area outside the user print area of each form C. The registration mark laser sensor 102 is a reflective optical sensor that detects the registration mark 103. The registration mark laser sensor 102 can detect that the continuous paper P conveyed during printing is displaced in the width direction by detecting the registration mark 103.

  A color registration mark laser sensor 104 is also provided at a position downstream of the image station 12Y on the paper transport path 15 of the continuous paper P of the front surface printing apparatus 2. That is, each of the image stations 12K, 12C, 12M, and 12Y prints the color registration mark 105 in a certain area outside the user printing area of each form paper C. The color registration mark laser sensor 104 is a reflective optical sensor that detects the color registration mark 105. By detecting the color registration mark 105, the color registration mark laser sensor 104 can detect a printing position shift between the image stations 12K, 12C, 12M, and 12Y.

  A roller sensor 106 is also provided at a position downstream of the image station 12Y on the paper transport path 15 of the continuous paper P of the front surface printing apparatus 2.

  FIG. 6 is an explanatory diagram for explaining the roller sensor 106. The roller sensor 106 includes a light emitting element 107 and a light receiving element 108 of a transmissive optical sensor, and a roller 109. The roller 109 is a disk-shaped member that contacts the surface of the continuous paper P moving on the paper transport path 15 and rotates as the continuous paper P moves. A plurality of holes 110 having the same shape and size pass through the roller 109 at a position equidistant from the center position of the disk of the roller 109. The holes 110 are arranged at equal intervals. The light emitting element 107 and the light receiving element 108 are arranged at positions where the holes 110 pass when the roller 109 rotates, and the rollers 109 rotate so that the hole 110 is positioned at a position where the light beam s emitted from the light emitting element 107 passes. For example, the light receiving element 108 can receive the light beam s, and the light receiving element 108 cannot receive the light beam s unless the hole 110 is positioned at the position where the light beam s passes. Therefore, if the continuous paper P is normally transported on the paper transport path 15, the light receiving element 108 does not receive the light beam s alternately, and the continuous paper P is normally transported on the paper transport path 15. If it is not transported, the light receiving element 108 receives the light beam s or does not receive it, so that it is possible to detect whether or not the continuous paper P is transported on the paper transport path 15.

  As shown in FIG. 5, for example, a stamp device 16 is provided at a position downstream of the fixing device 30 in the paper conveyance path 15. The stamp device 16 is a device that stamps the above-described print defect identification mark on a certain area outside the user print area of the form C. The print defect identification mark is detected by the skew detection sensor 101, the registration mark laser sensor 102, the color registration mark laser sensor 104, and the roller sensor 106 to detect abnormal image formation in the printer engine or abnormal paper conveyance in the paper conveyance path 15. This mark is formed on the form C that is determined to have a large degree of abnormality when the degree of abnormality is large. That is, the skew detection sensor 101, the registration mark laser sensor 102, the color registration mark laser sensor 104, or the roller sensor 106 determines that the image formation abnormality in the printer engine or the paper conveyance abnormality in the paper conveyance path 15 is larger than the set value. In this case, the form paper C for which the abnormality has been determined at a predetermined timing from the time of the determination is conveyed to the arrangement position of the stamp device 16, so that a printing defect identification mark is formed on the form paper C by the stamp device 16. .

  Of the front surface printing device 2 and the back surface printing device 3, the front surface printing device 2 uses the skew detection sensor 101, the registration mark laser sensor 102, the color registration mark laser sensor 104, or the roller sensor 106 to form an image on the printer engine. In this case, since it is also possible to form a printing defect identification mark on the form paper C by the printer engine of the back surface printing apparatus 3 when it is determined that the abnormality in the paper conveyance path 15 is large. The front surface printing apparatus 2 may not be provided with the stamp device 16.

  Next, detection of abnormality by the skew detection sensor 101, the registration mark laser sensor 102, the color registration mark laser sensor 104, and the roller sensor 106 will be described in detail. Each of the skew detection sensor 101 and the registration mark laser sensor 102 detects a deviation in the width direction of the continuous paper P as an example of detection of a paper transport abnormality in the paper transport path 15. The color registration mark laser sensor 104 detects, as an example of detection of abnormality in image formation by each printer engine, a shift in timing of image formation by each printer engine of the image stations 12K, 12C, 12M, and 12Y. The roller sensor 106 detects, for example, the occurrence of a jam of the continuous paper P as an example of detection of abnormality in paper conveyance in the paper conveyance path 15.

  First, detection of a deviation (skew) in the sheet width direction by the skew detection sensor 101 will be described with reference to FIG. If there is no deviation in the width direction of the continuous paper P, the skew detection sensor 101 does not detect the paper edge in the width direction of the continuous paper P. If there is such a deviation, the skew detection sensor 101 detects the paper edge in the width direction of the continuous paper P. However, a pair is provided at both ends of the continuous paper P in the width direction.

  As shown in FIG. 7C, when the skew detection sensor 101 detects a deviation in the width direction of the continuous paper P, its output signal becomes H level, and remains at the L level when no deviation is detected. . Then, the pulse width a when the output signal is at H level, that is, the detection time during which the edge portion in the width direction of the continuous paper P is continuously detected is compared with a preset threshold G, and the pulse width a It is determined whether or not the sheet conveyance abnormality of the continuous paper P, that is, the deviation in the width direction of the continuous paper P is large, depending on whether or not is less than the threshold G.

  FIG. 7A shows an example of an output signal of the skew detection sensor 101. “Sensor right” means that the skew detection sensor 101 on the right side in the conveyance direction of the continuous paper P and “sensor left” means “sensor left”. A skew detection sensor 101 on the left side in the conveyance direction of the continuous paper P is shown. The output signal example in FIG. 7A is an example in which the pulse width a is all equal to or less than the threshold value G and it is determined that the abnormality in paper conveyance is small. On the other hand, the output signal example in FIG. 7B is an example in which the pulse width a is larger than the threshold value G, and thus it is determined that the abnormality in paper conveyance is large.

  Next, the registration mark laser sensor 102 will be described with reference to FIG. The registration mark laser sensor 102 detects the registration mark 103. As shown in FIG. 8A, the registration mark 103 (second inspection image) has two sides facing each other in the width direction of the continuous paper P. There is a rectangular image in which the other two sides facing each other are the length direction of the continuous paper P, and a linear blank 103a in which the length direction forms an acute angle with the conveyance direction of the continuous paper P at the center. Crossing.

  When such a registration mark 103 is read in the length direction of the continuous paper P by the registration mark laser sensor 102, when the front mark 103b and the rear mark 103c separated by the blank space 103a are detected, the output signal is H level. Thus, when the blank 103a is detected, the output signal becomes L level. If the ratio of the H-level width b of the front mark 103b and the H-level width c of the rear mark 103c is substantially constant with respect to the pulse width of such an output signal, the registration mark laser sensor 103 is shown in FIG. As shown in scan A of FIG. 5B, the vicinity of the center of the registration mark 103 is detected, and it can be determined that no deviation in the width direction of the continuous paper P has occurred. Here, as shown in FIG. 8C, the ratio between the H level width b of the front mark 103b and the H level width c of the rear mark 103c (the ratio between the width b and the width c is 1: 2). If the ratio is equal to or smaller than the threshold value X, it is determined that the sheet conveyance abnormality is small, and the scanning B in FIGS. 8A and 8B is performed. As shown in FIG. 5, if this ratio exceeds the threshold value X, it is determined that the paper conveyance abnormality, that is, the deviation in the width direction of the continuous paper P is large.

  The skew detection sensor 101 and the registration mark laser sensor 102 both detect a deviation in the width direction of the continuous paper P, but the skew detection sensor 101 detects the entire continuous paper P that cannot be detected by the registration mark laser sensor 102. A shift in the width direction can be detected.

  The color registration mark laser sensor 104 will be described with reference to FIG. The color registration mark laser sensor 104 detects the color registration mark 105 (first inspection image).

  The color registration mark 105 is formed at a predetermined timing by the printer engines of the image stations 12K, 12C, 12M, and 12Y. That is, the color registration mark 105 includes a first color registration mark 105a and a second color registration mark 105b. The first color registration mark 105a is composed of first color registration marks 105aK, 105aC, 105aM, and 105aY, which are K, C, M, and Y color marks, respectively. The second color registration mark 105b also includes second color registration marks 105bK, 105bC, 105bM, and 105bY, which are K, C, M, and Y color marks, respectively. Here, the predetermined timing at which the color registration mark 105 is formed by the printer engines of the image stations 12K, 12C, 12M, and 12Y is as long as image formation is normally performed at the image stations 12K, 12C, 12M, and 12Y. The intervals between the first color registration marks 105aK, 105aC, 105aM, and 105aY and the intervals between the second color registration marks 105bK, 105bC, 105bM, and 105bY are all at equal intervals.

  The color registration mark 105 is used to determine whether or not the timing of image formation by the printer engines of the image stations 12K, 12C, 12M, and 12Y matches each other. The first color registration mark 105a is used for the continuous paper P. The shift in the length direction, that is, the shift in the sub-scanning direction (left and right direction in FIG. 9), the second color registration mark 105b is shifted in the width direction of the continuous paper P, that is, the shift in the main scanning direction (vertical direction in FIG. 9). ).

  In the color registration mark 105, if the timing of image formation by the printer engines of the image stations 12K, 12C, 12M, and 12Y is correct, both the first color registration mark 105a and the second color registration mark 105b are marks of each color. Are formed at equal intervals. In this case, the K, C, M, and Y toner images formed by the printer engines of the image stations 12K, 12C, 12M, and 12Y are superimposed on each other at an accurate position to form a color image. Become. FIG. 9A shows an example of this case. When the color registration mark 105 is read by the color registration mark laser sensor 104 by scanning C in the length direction of the continuous paper P, FIG. A scanning C signal which is an output signal is shown. The output signals of the color registration mark laser sensor 104 become H level when the first color registration marks 105aK, 105aC, 105aM, and 105aY and the second color registration marks 105bK, 105bC, 105bM, and 105bY are scanned. When the mark is not scanned, the level is L. If the timing of image formation by the printer engines of the image stations 12K, 12C, 12M, and 12Y matches each other, the pulse interval d of the output signal of the first color registration mark 105a, the second color registration mark 105b The output signal pulse intervals e are equally spaced as shown in FIG.

  On the other hand, in FIG. 9B, the timing of image formation by the printer engines of the image stations 12K, 12C, 12M, and 12Y does not match, and the first color registration marks 105aK, 105aC, 105aM, and 105aY are displayed. In the example, the second color registration marks 105bK, 105bC, 105bM, and 105bY are shifted from each other in the main scanning direction. At this time, the toner images of K, C, M, and Y colors formed by the printer engines of the image stations 12K, 12C, 12M, and 12Y are shifted from each other in the main scanning direction and the sub-scanning direction.

  As described above, when the image forming timings of the printer engines of the image stations 12K, 12C, 12M, and 12Y are shifted from each other in the sub-scanning direction or the main scanning direction, as shown in FIG. The first color registration mark 105a or the first color registration mark 105a of the scanning D signal which is the output signal of the color registration mark laser sensor 104 when the registration mark 105 is read by the color registration mark laser sensor 104 in the length direction of the continuous paper P by scanning D. The pulse interval d or e of the second color registration mark 105b is not constant. Therefore, thresholds of J and K (J <K) are prepared for the pulse intervals d and e, and if the pulse intervals d and e are within the numerical range of J to K, it is determined that the abnormality in image formation by the printer engine is small. When the pulse intervals d and e are smaller than J or larger than K, it can be determined that the abnormality in image formation by the printer engine is large.

  The roller sensor 106 will be described with reference to FIG. As described above, the roller 109 is in contact with the continuous paper P, and when the continuous paper P is transported and moved along the paper transport path 15, the roller 109 rotates to follow the movement of the continuous paper P. Therefore, the light beam s emitted from the light emitting element 107 passes through the hole 110 and enters the light receiving element 108, and the light beam s is reflected by the roller sensor 106 and does not enter the light receiving element 108.

  Therefore, when the continuous paper P is normally transported through the paper transport path 15, rectangular waves at substantially equal intervals are continuously output as the output signal of the roller sensor 106 as shown in FIG. Become. On the other hand, when the conveyance of the continuous paper P is stopped due to a jam or the like, the continuous output of rectangular waves at substantially equal intervals from the roller sensor 106 is stopped as shown in FIG. In this case, it can be determined that the abnormality in the conveyance of the continuous paper P is large.

  FIG. 11 is a block diagram of electrical connection of the printing system 1. The front surface printing apparatus 2 includes a CPU 111 that centrally controls each unit of the front surface printing apparatus 2, a ROM 112 that stores various control programs and fixed data, and a RAM 113 that is a work area of the CPU 111. Yes. Further, the bus 114 communicates with the NVRAM 115, an external connection device interface (hereinafter simply referred to as “I / F”) 116 that is a communication interface for communicating with an external device of the front surface printing device 2, and the print control device 101. A data input I / F 117 which is a communication interface for performing the above and a hard disk (HDD) 118 are connected to each other.

  Further, an operation panel 119 on which the user operates the front surface printing apparatus 2 is connected to the bus 114 via a predetermined graphical user interface I / F (hereinafter referred to as “GUI-I / F”) 120. Further, various actuators 121 of the surface printing apparatus 2 are connected via a drive circuit 122, and various sensors 123 of the surface printing apparatus 2 are connected via a sensor circuit 124 (various actuators 121 and various sensors 123 include various types. Various actuators and sensors are used, and various circuits are also used for the drive circuit 122 and the sensor circuit 124, but in FIG. 11, they are represented in this way for convenience (the same applies to each device described later).

  The back side printing apparatus 3 includes a CPU 131 that centrally controls each unit of the back side printing apparatus 3, a ROM 132 that stores various control programs and fixed data, and a RAM 133 that is a work area of the CPU 131 via a bus 134. Yes. Further, the bus 134 has an NVRAM 135, an external connection device I / F 136 that is a communication interface that communicates with an external device of the back surface printing device 3, and a data input I / F that is a communication interface that communicates with the print control device 101. F137 and HDD 138 are connected to each other.

  Furthermore, an operation panel 139 for allowing the user to operate the front surface printing apparatus 2 is connected to the bus 134 via a predetermined GUI-I / F 140. Various actuators 141 of the surface printing apparatus 2 are connected via a drive circuit 142, and various sensors 143 of the surface printing apparatus 2 are connected via a sensor circuit 144.

  The paper feeding device 4 includes a microcomputer and a control device 151 that centrally controls the whole paper feeding device 4. Connected to the control device 151 is an external connection device I / F 152 which is a communication interface for communicating with an external device of the paper feeding device 4. In addition, various actuators 153 of the paper feeding device 4 are connected to the control device 151 via a drive circuit 154, and various sensors 155 of the paper feeding device 4 are connected via a sensor circuit 156.

  The front / back reversing device 5 includes a microcomputer, and includes a control device 161 that centrally controls the entire front / back reversing device 5. Connected to the control device 161 is an external connection device I / F 162 which is a communication interface for communicating with an external device of the front / back reversing device 5. Various actuators 163 of the front / back reversing device 5 are connected to the control device 161 via a drive circuit 164, and various sensors 165 of the front / back reversing device 5 are connected via a sensor circuit 166.

  The post-processing device 6 includes a microcomputer and includes a control device 171 that centrally controls the entire post-processing device 6. Connected to the control device 171 is an external connection device I / F 172 which is a communication interface for communicating with an external device of the post-processing device 6. Further, various actuators 173 of the post-processing device 6 are connected to the control device 171 via a drive circuit 174, and various sensors 175 of the post-processing device 6 are connected via a sensor circuit 176.

  The host device 181 is connected to the front surface printing device 2 and the back surface printing device 3, and sends a print job to the front surface printing device 2 and the back surface printing device 3.

  FIG. 12 is a block diagram of electrical connection of the host device 181. The host device 181 performs various calculations and centrally controls the entire host device 181; a ROM 192 that stores various control programs executed by the CPU 191 and fixed data; a RAM 193 that serves as a work area for the CPU 191; A communication I / F 194 that communicates with the front surface printing apparatus 2 and the rear surface printing apparatus 3 is connected via a bus 195. Furthermore, an input device 196 such as a mouse and a keyboard and a display device 197 such as a liquid crystal display are connected to the bus 195 via a predetermined interface.

  With the above configuration, the front surface printing apparatus 2 and the back surface printing apparatus 3 communicate with the host apparatus 181 via the data input I / Fs 117 and 137 and the communication I / F 194. The front surface printing device 2, the back surface printing device 3, the paper feeding device 4, the front / back reversing device 5, and the post-processing device 6 are the external connection device I / F 116, the external connection device I / F 136, the external connection device I / F 152, and the external connection. They are connected via the device I / F 162 and the external connection device I / F 172, and can communicate with each other.

  By this communication, the paper feeding device 4 is controlled by the front surface printing device 2 and the like, the front / back reversing device 5 is controlled by the front surface printing device 2 and the back surface printing device 3, and the post-processing device 6 is controlled by the back surface printing device 3 and the like. The Thus, the front surface printing device 2, the back surface printing device 3, the paper feeding device 4, the front / back reversing device 5, and the post-processing device 6 perform a series of printing operations in conjunction with each other.

  That is, the front surface printing apparatus 2 and the back surface printing apparatus 3 perform continuous printing based on the print data transmitted from the host apparatus 181. The front surface printing device 2 prints the surface of the continuous paper P, and the printed continuous paper P is reversed by the front / back reversing device 5 and the back surface is printed by the back surface printing device 3. The post-processing device 6 performs processing such as separating the form papers C constituting the continuous paper P after printing and stacking the form papers C.

  Next, a control operation performed by the multiple printing system 1 will be described.

  FIG. 13 is a flowchart of processing executed by the front surface printing apparatus 2 (the CPU 111) and the back surface printing apparatus 3 (the CPU 131). Since the front side printing apparatus 2 (the CPU 111) and the back side printing apparatus 3 (the CPU 131) execute the same processing, here, the processing executed by the front side printing apparatus 2 (the CPU 111) will be described as a representative.

  Prior to starting the main printing based on the print data supplied from the host device 181, the continuous printing system 1 starts the conveyance of the continuous paper P and prints the color registration mark 105 on each form paper C of the continuous paper P. Whether this is detected by the color registration mark laser sensor 104 and the timing of image formation by the printer engines of the image stations 12K, 12C, 12M, and 12Y is not shifted from each other in the sub-scanning direction or the main scanning direction. When the pulse interval d or e of the first color registration mark 105a or the second color registration mark 105b is larger or smaller than the above-mentioned threshold values of J and K, the result is printed by each printer engine. To automatically correct the misalignment of the printing position by each printer engine. Then, when the pulse interval d or e of the first color registration mark 105a or the second color registration mark 105b falls within the numerical range of J to K by this, it is based on the print data supplied from the host device 181. Start full printing.

  In the main printing, the front surface printing apparatus 2 (the CPU 111) performs the processing shown in the flowchart of FIG.

  First, from the degree of abnormality detection by the skew detection sensor 101, the registration mark laser sensor 102, the color registration mark laser sensor 104, and the roller sensor 106, an abnormality in image formation by each printer engine or an abnormality in paper conveyance in the paper conveyance path 15 is described. It is determined for each form paper C whether or not there is an abnormality larger than a preset level (step S1).

  When the pulse width a when the output signal of the skew detection sensor 101 is at the H level is equal to or less than the threshold G, it is determined that the degree of detection of the paper conveyance abnormality in the paper conveyance path 15 is smaller than the preset level, and the pulse When the width a is larger than the threshold G, it is determined that the degree of abnormality detection is larger than a preset degree. If the ratio between the H-level width b of the front mark 103b and the H-level width c of the rear mark 103c is equal to or less than the threshold value X based on the detection signal of the registration mark laser sensor 102, an abnormality in paper conveyance in the paper conveyance path 15 is detected. If it is determined that the ratio is smaller than a preset level, and the ratio exceeds the threshold value X, it is determined that the abnormality in the sheet conveyance is larger than the preset level. If the pulse interval d or e of the first color registration mark 105a or the second color registration mark 105b is within the numerical range of J to K according to the output signal of the color registration mark laser sensor 104, the abnormality in image formation by the printer engine is detected. When the pulse intervals d and e are smaller than J or larger than K, it is determined that the abnormality in image formation by the printer engine is larger than the predetermined degree. When it is detected from the output signal of the roller sensor 106 that the paper conveyance of the continuous paper P is stopped due to a jam or the like, it is determined that the abnormality of the paper conveyance in the paper conveyance path 15 of the continuous paper P is larger than a preset level.

  Such a determination is made, and if the abnormality in image formation by each printer engine or the abnormality in paper conveyance in the paper conveyance path 15 is larger than a preset level (Y in Step S1), printing is stopped (Step S1). S2). Specifically, the printing in each printer engine is stopped, and the back surface printing apparatus 3 (CPU 131) is also instructed to stop printing in each printer engine. Further, it requests the back surface printing device 3 (the CPU 131) to synchronize the paper conveyance speed with the front surface printing device 2. Then, the paper conveyance speed is gradually reduced by the front surface printing device 2 to completely stop the paper conveyance, and in synchronization with this, the back surface printing device 3 also gradually reduces the paper conveyance speed to completely stop the paper conveyance. Let Further, the reason for canceling the printing is displayed on the operation panel 119 (step S3) to notify the user. In this case, since the degree of image formation abnormality by each printer engine or abnormality of paper conveyance in the paper conveyance path 15 is large, it is difficult to continue printing as it is, and the operation of the printing system 1 is stopped and the continuous paper is stopped. Necessary treatments such as releasing the jam of P are performed.

  When the abnormality in image formation by each printer engine or the abnormality in paper conveyance in the paper conveyance path 15 is smaller than a preset level (first degree) (N in step S1), each printer engine for each form paper C is determined. It is determined whether or not there is an abnormality in image formation due to or an abnormality in paper conveyance in the paper conveyance path 15 (step S4). That is, for each form paper C, the abnormality in image formation by each printer engine or the abnormality in paper conveyance in the paper conveyance path 15 is smaller than the first degree, but is set in advance as a value smaller than the first degree. When it is larger than the degree, it is judged that there is an abnormality, and when it is smaller than the second degree, it is judged that there is no abnormality. If there is an abnormality in image formation by each printer engine or an abnormality in paper conveyance in the paper conveyance path 15 (Y in step S4), there is an abnormality in image formation by each printer engine or an abnormality in paper conveyance in the paper conveyance path 15. In this case, the abnormality is smaller than a preset level. That is, although the output signal of the skew detection sensor 101 becomes H level, the width b of the front mark 103b at the H level when the pulse width a is equal to or smaller than the threshold G or by the detection signal of the registration mark laser sensor 102. When the ratio of the H level width c of the rear mark 103c is not normal but is equal to or less than the threshold value X, or according to the output signal of the color registration mark laser sensor 104, the first color registration mark 105a or the second color registration mark 105c. This is when the pulse interval d or e of the registration mark 105b is not normal but falls within the numerical range of J to K.

  In this case, printing continues as it is. However, in the case of normal printing, the print data of each form C supplied from the host device 181 is sequentially printed. In this case, since printing is performed in a state where an abnormality is detected, image formation by each printer engine is performed. As long as it is determined that there is an abnormality or an abnormality in paper conveyance in the paper conveyance path 15, printing of the same form paper C print data as when the abnormality was detected continues. In addition, a purge process is performed for separating the form paper C printed with the abnormality in this way from the form paper C normally printed by the post-processing device 6 (step S5). In this purge process, specifically, the above-described print defect identification mark is printed on each form paper C to be printed while abnormality is detected. Accordingly, the post-processing device 6 determines that the form paper C has a printing abnormality by reading the print defect identification mark by the mark detection sensor 51, and the form paper C is stored in the stacker 54 by the purge device 53. This is separated from the normal printed form C. Of course, as described above, regardless of the print defect identification mark, it is determined that the form paper C has a printing abnormality due to the paper conveyance distance of the continuous paper P and the like, and is separated from the normal printed form paper C. You may do it.

  An abnormal page counter A and an abnormal page counter B are prepared in a predetermined area of the RAM 113. The abnormal page counter A indicates how many forms C the abnormality continues when the abnormality of image formation by each printer engine or the abnormality of paper conveyance in the paper conveyance path 15 occurs once. This is a counter for counting the number of forms C to be printed. The abnormal page counter B starts the operation of the printing system 1 for the form paper C printed while there is an abnormality in image formation by each printer engine or an abnormality in paper conveyance in the paper conveyance path 15 and counts the total number of sheets thereafter. It is a counter for doing.

  That is, when there is an abnormality in image formation by each printer engine or an abnormality in paper conveyance in the paper conveyance path 15 (Y in step S4), 1 is added to the abnormal page counter A, and 1 is set in the abnormal page counter B. Add (step S6). When the value of the abnormal page counter A exceeds a predetermined number (first value) set in advance (Y in Step S7), the printing is stopped as described above (Step S2), and the printing is stopped. The reason for performing is displayed on the operation panel 119 (step S3). That is, even if an abnormality in image formation by each printer engine or an abnormality in paper conveyance in the paper conveyance path 15 occurs, these abnormalities may be resolved in a short time while printing is continued. That is, even if a deviation occurs between the images of the respective colors formed by the printer engines, the deviation may be resolved while printing is continued. Further, even if a deviation in the width direction of the continuous paper P occurs, the deviation may be eliminated while the printing is continued. Therefore, when the abnormal page counter A does not exceed the preset specified number (N in Step S7), even if an abnormal image formation by the printer engine or an abnormal paper conveyance in the paper conveyance path 15 occurs, Since the abnormality may be resolved, printing continues. On the other hand, when the abnormal page counter A exceeds a predetermined number set in advance (Y in step S7), an abnormality in image formation by the printer engine or an abnormality in paper conveyance in the paper conveyance path 15 takes some time. However, since the problem cannot be resolved naturally, the printing is stopped in the same manner as described above (step S2), and the reason why the printing is stopped is displayed on the operation panel 119 (step S3).

  When the value of the abnormal page counter B with respect to the total number of forms C to be printed by the printing system 1 exceeds a predetermined value (second value) set in advance (Y in step S8), printing is performed. In the system 1, the form paper C printed with the image forming abnormality by the printer engine or the paper conveyance path 15 in the paper conveyance path 15 with respect to the total number of forms C to be printed by one operation. Since the number of sheets is excessively large and it is difficult to continue printing with the printing system 1, the printing is stopped in the same manner as described above (step S <b> 2), and the reason why the printing is stopped is displayed on the operation panel. It is displayed on 119 (step S3). In this case, without stopping printing, only a warning that an abnormality in image formation by the printer engine or an abnormality in paper conveyance in the paper conveyance path 15 has occurred is displayed on the operation panel 119. Also good. Then, it suffices to determine whether to stop or continue printing according to the user's determination.

  The value of the abnormal page counter A does not exceed the predetermined number set in advance (N in step S7), and the value of the abnormal page counter B with respect to the total number of forms C to be printed by the printing system 1 is If the preset specified value is not exceeded (N in Step S8), if the print data of the form C to be printed by the printing system 1 still remains (Y in Step S9), Step S1 Returning to step S1, the processing from step S1 onward is executed in the printing of the next form paper C. When the print data of all form paper C has been printed (N in step S9), the series of processing is terminated.

  On the other hand, when there is no abnormality in image formation by each printer engine or abnormality in paper conveyance in the paper conveyance path 15 (N in step S4), it is determined whether or not a numerical value of 1 or more is stored in the abnormal page counter A. (Step S10) If a numerical value of 1 or more is stored (Y in Step S10), the abnormal page counter A is cleared to 0 (Step S11). That is, when a numerical value of 1 or more is stored in the abnormal page counter A, there is an abnormality in image formation by each printer engine or abnormality in paper conveyance in the paper conveyance path 15 in the printing of the form paper C up to the previous time. (Y in step S4), and then the abnormal page counter A is set to 0 because the abnormal page counter A has been eliminated without exceeding the predetermined number set in advance, and the current form paper C is printed. It is something to clear. In this case, since there is no abnormality in image formation by each printer engine or abnormality in paper conveyance in the paper conveyance path 15, printing continues normally, and the print data of the form paper C transmitted from the host device 181 is continuous paper P. Are printed sequentially.

  In step S5, if there is an abnormality in image formation by each printer engine or an abnormality in paper conveyance in the paper conveyance path 15, printing is performed on the same form C print data as when the abnormality was detected until the abnormality is resolved. However, in this case, when the abnormal page counter A is cleared to 0, the first form paper C is printed because the print data of the same form paper C is printed as when the abnormality is detected. The printing of the print data is resumed, and the subsequent print data of the form C is sequentially printed. As a result, the print data of all the forms C are normally printed.

  The printed form C after step S10 is stored in the stacker 54 of the post-processing device 6 without performing the purge process (step S5), assuming that it has been printed normally. Thereafter, if the print data of the form paper C to be printed by the printing system 1 still remains (Y in step S9), the process returns to step S1, and when the print data of all the form paper C is printed (step S9). N), a series of processing is terminated.

  The processing executed by the front surface printing apparatus 2 has been described above with reference to the flowchart in FIG. 13, but the back surface printing apparatus 3 (the CPU 131) performs the same processing as in the flowchart in FIG. 13. Therefore, whether an abnormality in image formation by each printer engine or an abnormality in paper conveyance in the paper conveyance path 15 occurs in the front surface printing apparatus 2 or in the rear surface printing apparatus 3, it is described above with reference to the flowchart of FIG. Will be executed. A control device that centrally controls the printing system 1 is prepared separately from the front surface printing device 2 and the back surface printing device 3, and is the same as that described with reference to the flowchart of FIG. 13 by centralized control by the control device. You may make it perform the process of.

  According to the printing system 1 described above, even if an abnormality in image formation by each printer engine or an abnormality in paper conveyance in the paper conveyance path 15 occurs, printing is not stopped immediately, and the abnormality can be resolved naturally. Since the process waits, printing can be interrupted, and a large amount of continuous paper P can be suppressed in the long paper transport path of the printing system 1. In addition, even if some abnormalities in image formation by each printer engine or abnormalities in paper conveyance in the paper conveyance path 15 occur, the printing process is not stopped immediately, so that the productivity of the printing process that occurs due to the cancellation of printing is reduced. Can be prevented.

[Embodiment 2]
FIG. 14 is an explanatory diagram showing the overall configuration of the printing system of the present embodiment. In the following description, members and the like having the same reference numerals as those in the first embodiment described with reference to FIGS. 1 to 13 are the same as those in the first embodiment, and detailed description thereof is omitted.

  The printing system 201 according to the present embodiment is different from the printing system 1 according to the first embodiment in that printing is performed by the printer engines of the image stations 12K, 12C, 12M, and 12Y in the front surface printing apparatus 2 and the back surface printing apparatus 3. That is, the printing plate printing method is used instead of the electrophotographic method. Since the printing method is not the electrophotographic method but the printing plate printing method, the fixing device 30 is not provided.

  FIG. 15 is an explanatory diagram of the printer engine 13K of the image station 12K. Since the printer engine using the printing plate printing method in each of the image stations 12K, 12C, 12M, and 12Y has a common configuration, the printer engine 13K of the image station 12K will be described here as a representative.

  The printer engine 13K uses a screen printing method, which is a typical stencil printing method, as an example of a plate printing method. Screen printing uses screen eyes woven with stainless steel wire. That is, a plate film (resist) is made on the screen by a handicraft or an optical engineering (photographic) method, and the portions other than the necessary image line (image line portion) (non-image area portion) are closed. As a result, a printing plate 301 is made to be a plate cylinder 302.

  The plate cylinder 302 is opposed to the impression cylinder 304 with the continuous paper P interposed therebetween. Ink i is put into the plate cylinder 302, and the plate cylinder 302 is rotated while pressurizing the inner surface of the plate cylinder 302 with a squeegee 303 formed of a spatula-like rubber plate or the like provided inside the plate cylinder 302. As a result, the squeegee 303 moves while pressurizing the inner surface of the plate cylinder 302. Then, the ink i passes through the screen of the plate cylinder 302 in the portion (image line portion) where there is no plate film and is pushed out to the printing surface of the continuous paper P to perform printing.

  FIG. 16 is an explanatory diagram of sensors provided in the front surface printing apparatus 2 and the back surface printing apparatus 3, respectively. This figure shows the sheet transport path 15 in a straight line, and shows the continuous paper P and the image stations 12K, 12C, 12M, and 12Y on the sheet transport path 15 from the lower side (image stations 12K, 12C, and 12M). , 12Y, only the plate cylinder is shown, and the impression cylinder and the like are not shown). Since the front surface printing apparatus 2 and the back surface printing apparatus 3 have the same sensors as described here, the front surface printing apparatus 2 will be described below as a representative. The difference from the sensors of the first embodiment described with reference to FIG. 5 is that the color registration mark laser sensor 104 is not provided, and the color registration mark 105 is continuously printed by the image stations 12K, 12C, 12M, and 12Y. It is not formed on P. In the printing system 201 of the second embodiment, the processing described above with reference to FIG. 13 is also performed. However, since the color registration mark laser sensor 104 is not provided, the determination in steps S1 and S4 is performed by the skew detection sensor 101 and the registration. Detection of the mark laser sensor 102 and the roller sensor 106 is performed.

  According to the printing system 201 described above, even if some abnormality in the paper conveyance path 15 occurs, the printing is not stopped immediately, and it waits for the abnormality to be resolved naturally. It is possible to suppress a large amount of continuous paper P from being damaged in the long paper conveyance path of the system 1. Also, even if some paper conveyance abnormality occurs in the paper conveyance path 15, printing is not stopped immediately, so that it is possible to prevent a decrease in productivity of printing processing that occurs when printing is stopped.

  As mentioned above, although several embodiment of this invention was described, it cannot be overemphasized that this invention is not limited to the content of each above-mentioned embodiment.

  For example, the front surface printing apparatus 2 and the back surface printing apparatus 3 do not include all of the cue detection sensor 101, the registration mark laser sensor 102, the color registration mark laser sensor 104, and the roller sensor 106, but one type of these or Only two types may be provided. Alternatively, in addition to these sensors, a sensor that detects an abnormality in image formation by the printer engine or an abnormality in the conveyance of the continuous paper P in the paper conveyance path 15 and its degree may be provided.

  In each of the above-described embodiments, an example of a printing system that performs continuous printing by the front surface printing device 2 and the back surface printing device 3 has been described, but multiple continuous printing is performed using three or more printing devices. The printing system may be configured with only one printing apparatus.

  Further, both the front surface printing apparatus 2 and the back surface printing apparatus 3 are examples of a printing system that prints a color image using four image stations 12K, 12C, 12M, and 12Y, but each printing apparatus has only one image station. A system that prints a single-color image such as K may be used, or a system that prints two-color images using two image stations.

  In the second embodiment, a stencil printing method, more specifically an example of a screen printing method, is described as an example of a printing plate printing method. However, other printing plate printing methods, for example, lithographic printing such as an offset printing method are used. An intaglio printing method such as a printing method, a gravure printing method, a relief printing method, or the like may be used.

  Further, although an example of an electrophotographic method is described in the first embodiment and an example of a printing plate printing method is described in the second embodiment, as other printing methods, a silver salt photographic method, a thermal transfer method (sublimation type thermal transfer method, fusion type) Various printing methods such as a thermal transfer method and a direct thermal recording method can be applied.

It is explanatory drawing of the whole structure of the printing system concerning Embodiment 1 of this invention. It is explanatory drawing which shows schematic structure of a surface printing apparatus and a back surface printing apparatus. It is the top view (a) and front view (b) of a front-back inversion device. It is explanatory drawing of a post-processing apparatus. It is explanatory drawing about the sensors provided in the surface printing apparatus and the back surface printing apparatus, respectively. It is explanatory drawing explaining a roller sensor. It is a timing chart explaining a skew detection sensor. It is a timing chart explaining a registration mark laser sensor. It is a timing chart explaining a color registration mark laser sensor. It is a timing chart explaining a roller sensor. It is a block diagram of the electrical connection of a printing system. It is a block diagram of the electrical connection of a host apparatus. It is a flowchart of the process which a front surface printing apparatus and a back surface printing apparatus perform. It is explanatory drawing of the whole structure of the printing system concerning Embodiment 2 of this invention. It is explanatory drawing explaining a screen printing system. It is explanatory drawing about the sensors provided in the surface printing apparatus and the back surface printing apparatus, respectively.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printing system 2 Front surface printing apparatus 3 Back surface printing apparatus 4 Paper feeding apparatus 6 Post-processing apparatus 201 Printing system P Continuous paper C Form paper

Claims (13)

A supply device for supplying a continuous print medium;
A printing apparatus for printing a unit image on a print medium supplied from the supply apparatus;
With
The printing apparatus includes:
A transport path for transporting a print medium supplied from the supply device;
A printer engine for printing on the print medium on the transport path;
Have
An abnormality detection means for detecting the presence or absence and the degree of at least one of an abnormality in image formation by the printer engine and an abnormality in conveyance of the print medium in the conveyance path;
When it is determined that the degree of abnormality in image formation by the printer engine detected by the abnormality detection unit or the degree of abnormality in conveyance of the print medium in the conveyance path is larger than a preset first degree, the printing apparatus Printing is stopped, and the degree of abnormality in image formation by the printer engine or abnormality in conveyance of the print medium in the conveyance path is smaller than the first degree and larger than a preset second degree and the first degree. A printing control means for continuing printing by the printing apparatus when it is determined that the printing apparatus is smaller than 1,
Equipped with a,
further,
A plurality of the printing devices are provided,
The plurality of printing apparatuses are connected in cascade with each other, and the printing is performed by performing different printing of the unit images by sharing different portions of the unit images with respect to the print medium supplied from the supply apparatus. Continuously printing the unit images on a medium;
Each of the printing apparatuses includes a plurality of the printer engines that print images of different colors, and forms the images of different colors that are printed by the plurality of printer engines on the print medium. To print a color image,
The abnormality detecting means detects whether or not there is an abnormality in image formation by the printer engine and the degree thereof, and whether or not there is a positional deviation between different color images printed by a plurality of printer engines of the printing apparatus. A printing system further comprising a displacement detection means .   The printing control unit determines that the degree of abnormality in image formation by the printer engine or the abnormality in conveyance of the print medium in the conveyance path is larger than the second degree and smaller than the first degree. When printing a predetermined number of the unit images without continuing the printing by the above, and the degree of abnormality of the image formation or the abnormality of conveyance of the print medium in the conveyance path is not smaller than the second degree, The printing system according to claim 1, wherein printing by the printing apparatus is stopped. The abnormality detecting means includes a printing medium position deviation detecting means for detecting whether or not there is an abnormality in the conveyance direction of the print medium in the conveyance path and the degree thereof, and whether or not there is a deviation in the width direction of the print medium in the conveyance path. the system according to claim 1 or 2, further comprising. The abnormality detection unit further includes an image position deviation detection unit,
The image displacement detection means is
First inspection image forming means for forming a first inspection image on the print medium by each printer engine at a predetermined timing;
First inspection image reading means for reading the first inspection image formed by the inspection image forming means on the print medium in a length direction of the print medium;
First inspection image interval detection means for detecting an interval between the first inspection images formed by the printer engines read by the first inspection image reading means;
First determining whether or not there is a positional shift between images of different colors printed by each printer engine based on the interval between the first inspection images detected by the first inspection image interval detecting means. Image inspection means for inspection,
The system according to claim 1 or 2, further comprising a. The first inspection image forming means includes, as the first inspection image, an image in which the length direction is the width direction of the print medium on the print medium by the printer engines, Form an image that forms an acute angle with the width direction of the print medium,
The first inspection image interval detection means includes the first inspection image whose length direction is the width direction of the print medium and the first direction in which the length direction forms an acute angle with the width direction of the print medium. Detecting an interval between the first inspection images for each of the inspection images,
The first inspection image determination means includes the first inspection image whose length direction is the width direction of the print medium, and the image between different colors printed by the respective printer engines according to the interval of the first inspection image. The presence / absence of the positional deviation in the length direction of the print medium and the degree thereof are determined, and printing is performed by each printer engine according to the interval of the first inspection images whose length direction forms an acute angle with the width direction of the print medium. Determining whether or not there is a positional deviation in the width direction of the print medium between images of different colors;
The printing system according to claim 4 . The printing medium positional deviation detecting means is
A rectangular image in which two sides facing each other on the print medium by any one of the printer engines are the width direction of the print medium and the other two sides facing each other are the length direction of the print medium, A second inspection image forming means for forming a second inspection image in which a blank space on a line whose length direction forms an acute angle with the width direction of the print medium intersects in the center of
Second inspection image reading means for reading the second inspection image formed by the inspection image forming means on the print medium in the length direction of the print medium;
Second inspection image interval detection means for detecting the interval between the front and rear portions of the blank of the second inspection image read by the second inspection image reading means;
Second inspection for determining whether or not there is a deviation in the width direction of the print medium in the transport path based on the intervals of the second inspection image detected by the second inspection image interval detecting means. Image determination means;
The printing system according to claim 3 , further comprising: The printing medium positional deviation detecting means is
Edge part detection means provided respectively at edge parts on both sides in the width direction of the print medium of the transport path, each detecting an edge part in the width direction of the print medium;
Detection time determination means for determining whether or not there is a deviation in the width direction of the print medium in the transport path based on detection time of the edge portion by the edge portion detection means and detection time in which the detection is continuously performed. When,
The printing system according to claim 3 , further comprising: For each unit image after printing by the printing apparatus, the abnormality detection means causes the printer engine to have an image formation abnormality or a conveyance abnormality of the print medium in the conveyance path smaller than the first degree. Identifying means for distinguishing between printing performed by the printing control means while it is determined that the degree is greater than a degree and printing performed while the degree of abnormality is smaller than the second degree;
Cutting means for cutting the print medium for each unit image;
About the print medium for each unit image after being cut by the cutting means, the degree of abnormality of image formation by the printer engine or abnormality of conveyance of the print medium in the conveyance path by the identification means is smaller than the first degree. Separating means for performing printing by the print control means while it is determined that the degree is greater than the second degree, and for performing printing while the degree of abnormality is smaller than the second degree;
The printing system according to any one of claims 1 to 7 , further comprising: The identification means includes
An identification mark for distinguishing between each unit image after printing by the printing apparatus and the one printed by the printing control means while detecting the abnormality and the one printed without detecting the abnormality An identification mark forming means formed on
An identification mark reading means for reading the identification mark of the print medium;
About each unit image after printing by the printing apparatus, printing is performed without detecting the abnormality and what is printed by the print control unit while the abnormality is detected by the identification mark read by the identification mark reading unit. Unit image identification means for identifying
The printing system according to claim 8 , further comprising: When the abnormality detection unit detects an abnormality in image formation by the printer engine or an abnormality in the conveyance of the print medium in the conveyance path, and the degree of the abnormality is smaller than the first degree and larger than the second degree. A first counting means for counting the number of unit images that are continuously printed as determined;
The printing control unit stops printing by the printing device when the number of unit images counted by the first counting unit exceeds a preset first value;
The printing system according to claim 2. When the value detected by the abnormality detection unit becomes smaller than the second level without the value counted by the first counting unit exceeding the first value, the first counting unit counts the value. The printing system according to claim 10 , further comprising: numerical value clearing means for clearing the numerical value that has been set. When the abnormality detection unit detects an abnormality in image formation by the printer engine or an abnormality in the conveyance of the print medium in the conveyance path, and the degree of the abnormality is smaller than the first degree and larger than the second degree. A second counting means for counting the total number of the unit images printed as determined;
The printing control means sets a second value in which a ratio of the number of unit images counted by the second counting means to a total number of the unit images to be printed by the printing apparatus is set in advance. When exceeded, stop printing by the printing device,
The printing system according to any one of claims 1 to 11 . A print data supply means for supplying print data of each unit image to be printed on the print medium;
The printing apparatus sequentially prints the print data of each unit image supplied by the print data supply unit on the print medium,
The print control means detects an abnormality in image formation by the printer engine or an abnormality in transport of the print medium in the transport path by the abnormality detection means, and the degree of the abnormality is smaller than the first degree and the second. When it is determined that the abnormality is larger than the second degree and the printing apparatus continues printing by the printing apparatus, the print data of the unit image when the abnormality is first detected until the degree of the abnormality is smaller than the second degree. When the abnormality is resolved, printing of the unit image is resumed from the print data of the unit image at the time of the first detection.
The printing system according to any one of claims 1 to 12 .

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