JP5787396B2 - Stencil printing machine - Google Patents

Description

  The present invention relates to a stencil printing apparatus that performs printing with a printing drum. More specifically, the present invention relates to a stencil printing apparatus that forms an ink reservoir in a printing drum and supplies ink in the ink reservoir to the printing drum for printing.

  Conventionally, a stencil printing apparatus that realizes high-speed printing by feeding paper while rotating a printing drum is known. In such a stencil printing apparatus, an ink reservoir extending in the rotation axis direction of the printing drum is formed in the printing drum, and ink in the ink reservoir is supplied to the printing drum.

  By the way, the ink supplied to the printing drum is not consumed evenly by printing. For example, the portion of the printing drum that performs solid printing consumes more ink than the portion that does not perform solid printing. As a result, the ink consumption is naturally increased in the area of the ink reservoir where the ink is supplied to the portion where the solid printing is performed.

  Therefore, there is a possibility that a predetermined deviation exists between a plurality of areas in which the ink reservoir during printing is virtually divided in the rotation axis direction of the printing drum, that is, a so-called ink amount deviation may occur. When such a deviation in the ink amount occurs, the printed image may be wrinkled.

  In Patent Document 1, a supply path from an ink pump is provided so that the presence or absence of ink is detected at a plurality of positions spaced apart by a predetermined interval in the longitudinal direction of the ink reservoir, and the ink is supplied only to the vicinity where no ink is detected. Switching techniques have been proposed.

JP 2001-328337 A

  However, in the technique proposed in Patent Document 1, an ink supply path switching device is required to prevent dripping due to uneven ink amount, which may increase the cost.

  In view of the circumstances described above, an object of the present invention is to provide a stencil printing apparatus that can prevent cost increase and curl due to uneven ink amount.

  In order to solve the above-described problems, a stencil printing apparatus according to the present invention includes a rotatable printing drum on which a stencil sheet is wound, a printing drum driving unit that rotationally drives the printing drum, and a rotation of the printing drum. A paper feeding means for feeding paper toward the printing drum, a squeegee roller inscribed in the printing drum, and an ink receiving portion that is disposed in the vicinity of the squeegee roller and extends in the rotation axis direction of the printing drum. A doctor roller, an ink supply means for supplying ink to the ink receiving portion, and an ink between a plurality of regions in which the ink reservoir stored in the ink receiving portion is partitioned in the rotation axis direction of the printing drum during rotation of the printing drum And an ink deviation detecting unit that detects a predetermined amount deviation as an ink amount deviation. When the ink deviation detecting unit detects an ink amount deviation, While rotating the, and further comprising a control means for controlling the printing drum drive means and the sheet feeding means so as to stop the feeding of the sheet.

  Here, “in response to the rotation of the printing drum” in the stencil printing apparatus of the present invention means synchronization with the rotation of the printing drum. The above “inscribed” not only means that the printing drum and the squeegee roller are completely in contact with each other, but also has a gap enough to form an ink film between the printing drum and the squeegee roller. It means to include the state.

  In the stencil printing apparatus of the present invention, the ink deviation detecting means includes a sensor that detects whether or not the amount of ink in each region is equal to or greater than a predetermined amount, and based on the output of the sensor, at least one region In this case, the ink amount is biased when the state less than the predetermined amount for a predetermined time continuously occurs within the predetermined period, and the state less than the predetermined amount for the predetermined time does not occur in other regions other than at least one region. May be.

  Further, in the stencil printing apparatus of the present invention, the ink deviation detecting means calculates a perforation rate for each block of the stencil sheet corresponding to each region using the stencil sheet making data, and the minimum perforation in the perforation rate of each block When the difference between the rate and the maximum perforation rate exceeds a threshold value, the ink amount is biased. When the control unit detects the ink amount bias, the printing drum has a first predetermined number. The paper supply is stopped until it rotates, the paper is supplied in accordance with the second predetermined number of rotations after the first predetermined number of rotations, and then the paper supply is stopped until the first predetermined number of rotations. The printing drum driving unit and the sheet feeding unit may be controlled to repeat the sheet feeding process according to the second predetermined number of rotations after one predetermined number of rotations. Here, the “perforation rate” in the stencil printing apparatus of the present invention means the ratio of the perforated pixels to the total pixels in each block.

  The stencil printing apparatus of the present invention further comprises temperature detecting means for detecting the temperature in the printing drum, and the ink deviation detecting means detects the temperature not more than a predetermined temperature, and the minimum punching rate in the punching rate of each block. If the difference between the maximum perforation rate and the maximum perforation rate exceeds a threshold value, the ink amount may be biased.

  Further, in the stencil printing apparatus of the present invention, when the control means detects the deviation of the ink amount by the ink deviation detection means, the paper feeding is stopped until the printing drum rotates a predetermined number of times, and the next after the predetermined number of rotations. The printing drum driving means and the paper feeding means are controlled so as to repeat the process of feeding paper according to the rotation of the paper, and then stopping the paper feeding until a predetermined number of rotations and refeeding after the predetermined number of rotations. It may be.

  According to the stencil printing apparatus of the present invention, the ink deviation detecting means detects the ink amount between a plurality of areas partitioned in the rotation axis direction of the printing drum by collecting the ink reservoir stored in the ink receiving portion during rotation of the printing drum. When a predetermined deviation is detected as an ink quantity deviation, and the ink deviation detection means detects an ink quantity deviation, the control means drives the printing drum to stop paper feeding while rotating the printing drum. Since the means and the paper feeding means are controlled, it is possible to prevent the printing from being interrupted and the occurrence of wrinkles in the printed image. Further, there is no need to switch the supply path, and the cost can be avoided.

  According to the stencil printing apparatus of the present invention, the ink deviation detection means includes a sensor that detects whether or not the ink amount is greater than or equal to a predetermined value in each region, and based on the output of the sensor, at least one In order to detect a case where a state less than a predetermined amount for a predetermined time continuously occurs in a region and a state less than the predetermined amount for a predetermined time does not occur in other regions other than at least one region, It is possible to accurately detect the deviation and prevent the occurrence of wrinkles in the printed image.

  Further, according to the stencil printing apparatus of the present invention, the ink deviation detecting means calculates the perforation rate for each block of the stencil sheet corresponding to each region using the stencil sheet making data, and the perforation rate of each block A case where the difference between the minimum perforation rate and the maximum perforation rate exceeds a threshold is detected as an ink amount deviation, and when the control means detects the ink amount deviation, the printing drum has a first predetermined number. The paper supply is stopped until it rotates, the paper is supplied in accordance with the second predetermined number of rotations after the first predetermined number of rotations, and then the paper supply is stopped until the first predetermined number of rotations. In order to control the printing drum driving unit and the sheet feeding unit so as to repeat the sheet feeding process in accordance with the second predetermined number of rotations after the predetermined number of rotations of 1, a deviation in the ink amount can be predicted and Can prevent drowning.

  Further, according to the stencil printing apparatus of the present invention, the temperature detection means detects the temperature in the printing drum, and the ink deviation detection means detects that the detected temperature is equal to or lower than a predetermined temperature, and the minimum perforation in the perforation rate of each block. When the difference between the ink rate and the maximum perforation rate exceeds the threshold value, it is detected as a deviation in the ink amount. Can be prevented.

  Further, according to the stencil printing apparatus of the present invention, when the ink deviation detecting means detects the deviation of the ink amount, the control means stops the paper feeding until the printing drum rotates a predetermined number, and after the predetermined number of rotations The printing drum driving unit and the sheet feeding unit are controlled so as to repeat the process of feeding the sheet according to the next rotation, and then stopping the sheet feeding until a predetermined number of rotations and refeeding after the predetermined number of rotations. Therefore, it is possible to prevent the occurrence of wrinkles in the printed image while continuing the printing by extending the printing cycle.

Schematic configuration diagram of stencil printing machine Block diagram of stencil printing machine Partial enlarged view of stencil printing machine (Part 1) Partial enlarged view of stencil printing machine (Part 2) The flowchart which shows the process after it detects from the detection of the deviation | shift of the ink amount in 1st Embodiment. Schematic configuration diagram of an ink deviation detection unit in the second embodiment (No. 1) Schematic configuration diagram of an ink deviation detection unit in the second embodiment (No. 2) The flowchart which shows the process after it detects from the detection of the deviation | shift of the ink amount in 2nd Embodiment. The flowchart which shows the process after it detects from the detection of the deviation | shift of the ink amount in 3rd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of a stencil printing apparatus 1 according to the first embodiment of the present invention. As shown in FIG. 1, the stencil printing apparatus 1 includes a document reading unit 10 that reads a document, a plate making unit 20 that performs a plate making process on the stencil sheet M based on image information read by the document reading unit 10, and a plate making unit 20. A printing unit 30 that prints on printing paper using the stencil sheet M that has been made, a paper feeding unit 40 that feeds the printing paper to the printing unit 30, a paper discharge unit 50 that discharges the printed printing paper, and a used stencil A plate discharging unit 60 to which the base paper M ′ is fed, a display unit 70 for displaying predetermined items and receiving an input of predetermined printing conditions, an ink deviation detecting unit 80 for detecting a deviation in ink amount, and a control unit 90 for controlling each unit. It has. Note that the stencil printing apparatus 1 may be configured to directly receive image information from a personal computer or the like without including the original reading unit 10.

  The document reading unit 10 includes a document table 11 on which a document is placed, a pressing plate 12 that presses the document placed on the document table 11, a line image sensor 13 that photoelectrically reads image information of the document, and a line And a sensor transport unit 14 that transports the image sensor 13 in the sub-scanning direction (the direction of arrow A in FIG. 1). The sensor transport unit 14 includes a transport belt 14a to which the line image sensor 13 is attached, and a transport roller 14b that transports the transport belt 14a.

  The plate making unit 20 includes a base paper roll unit 21, a plate making unit 22 having a thermal head in which a plurality of heating elements are arranged in a row, and a base paper feed roller 23 that feeds the stencil sheet M fed from the base paper roll unit 21. 24, a drive motor 25 for driving the rotation of the base paper feed rollers 23, 24, and a base paper cutter 26 for cutting the stencil base paper M fed by the base paper feed rollers 23, 24 to a predetermined length.

  The printing unit 30 is an ink-permeable cylindrical printing drum 31, a squeegee roller 32 disposed so as to be substantially inscribed in the printing drum 31, and a squeegee roller 32. A doctor roller 33 that forms an ink receiving portion R that extends in a direction perpendicular to the paper surface, an ink supply means 34 that supplies ink to the ink receiving portion R, and presses the paper P toward the printing drum 31. A press roller 35, an ink drive rod 36 disposed between the ink supply means 34 and the ink receiving portion R, and a print drum drive means 37 for rotating the print drum 31. A stencil sheet M is wound around the outer periphery of the printing drum 31. Ink from the ink supply means 34 is stored in the ink receiving portion R to form an ink reservoir AI.

  The paper feed unit 40 has a paper feed table 41 on which the print paper P is placed, and a primary paper feed roller 42 that takes out the print paper P one by one from the paper feed table 41 and sends it to the secondary paper feed roller 43. The leading end of the printing paper P that is disposed downstream of the primary paper feeding roller 42 in the carrying direction is temporarily stopped, and the printing paper P is pressed against the printing drum 31 at a predetermined timing. A secondary paper feed roller 43 is provided between the roller 35 and the roller 35.

  The paper discharge unit 50 peels off the printed printing paper P ′ from the printing drum 31, and the paper discharge tray described later on the printed printing paper P ′ peeled off from the printing drum 31 by the peeling claw 51. A paper discharge feeding belt unit 52 that conveys the printed printing paper P ′ conveyed by the paper discharge feeding belt unit 52 is provided.

  The plate discharging unit 60 is provided on one side of the printing unit 30 and pulls the used stencil sheet M ′ from the printing drum 31 and the plate discharging box 61 into which the used stencil sheet M ′ peeled off from the printing drum 31 is fed. A plate discharging roller 62 that peels off and feeds it into the plate discharging box 61 is provided.

  The display unit 70 is configured by a known display panel such as a liquid crystal panel or an LED panel. The display panel displays a message for prompting the operation state of the apparatus and replacement of the ink container, and also relates to a printing density such as a printing pressure at which the press roller 35 presses the printing drum 31 and a size of perforation at the time of plate making. The setting contents related to the setting contents and the printing speed (rotation speed of the printing drum) are displayed.

  In addition, the display unit 70 is configured to accept input by the operator regarding the setting contents regarding the print density and the printing speed, and to change these setting contents. The display unit 70 is configured to accept an input of a desired number of printed sheets and the number of printed copies by an operator and set them.

  The ink deviation detection unit 80 detects an ink quantity deviation while the printing drum 31 is rotating. Here, the deviation of the ink amount is the deviation of the ink between the areas when the ink reservoir AI stored in the ink receiving portion R is virtually divided into a plurality of areas in the rotation axis direction of the printing drum 31. is there.

  As shown in FIG. 2, the control unit 90 includes a document reading unit 10, a plate making unit 20, a printing unit 30, a paper feeding unit 40, a paper discharging unit 50, a plate discharging unit 60, a display unit 70, and an ink deviation detecting unit 80. Each part is controlled by connecting and outputting a control signal to each part.

  Next, the printing unit 30 and the ink deviation detection unit 80 will be described in detail. 3 and 4 are partially enlarged views of the stencil printing apparatus 1. FIG. The printing drum 31 rotates in the direction of arrow A in the figure. The squeegee roller 32 is arranged in the printing drum 31 with a predetermined gap, and rotates in the direction of arrow B in the figure while inscribed in the printing drum 31 through an ink film formed in the gap. The doctor roller 33 is fixed to the stencil printing apparatus 1 at a position spaced from the squeegee roller 32 by a predetermined gap.

  The ink supply unit 34 includes an ink bottle 341 and an ink distributor 342 that distributes the ink in the ink bottle 341 and discharges the ink to the ink receiving portion R. The ejection ports 343 of the ink distributor 342 are arranged at a predetermined interval in the rotation axis direction of the printing drum 31. The ink driving rod 36 rotates in the direction of arrow C in the figure between the ejection port 343 and the ink receiving portion R. The ink reservoir AI flows by the rotation of the squeegee roller 32 and the ink driving rod 36 and is extended in the direction of the rotation axis of the ink driving rod 36.

  The ink deviation detection unit 80 detects whether or not the ink has a predetermined amount for each of a plurality of regions obtained by virtually dividing the ink reservoir AI stored in the ink receiving unit R in the rotation axis direction of the printing drum 31. A plurality of ink sensors 81 are provided. The ink sensor 81 includes a detection probe 811 that is in contact with ink, and outputs a signal (hereinafter referred to as an ink detection signal) indicating that the detection probe 811 is in contact with ink.

  In the first embodiment, the ink deviation detection unit 80 includes an ink monitor 82 that detects an ink amount deviation by monitoring an ink detection signal from the ink sensor 81.

  The ink monitor 82 includes a plurality of ink sensors 81 that continuously generate an ink detection signal for a predetermined period of time. In addition to the ink sensor 81, an ink sensor 81 that does not output an ink detection signal for a predetermined period of time. Is detected as a deviation in the ink amount.

  The ink monitor 82 indirectly has a predetermined height in at least one area by the above monitoring not more than the printing cycle and does not have a predetermined height in other areas other than at least one area. Monitoring when the time exceeds the printing cycle.

Ink monitor 82 is, for example, monitor the when 20 seconds ink detection signal within 120 seconds duration ink sensor 81 which state continues 2-5 times the non-output is present at least one, in addition to the ink sensor 81, Ink amount deviation may be detected when there is at least one ink sensor 81 that does not generate a state in which an ink detection signal is not output for 20 seconds within a 120-second period. Note that the above-described period and the time during which no output is performed are not particularly limited.

Next, the operation of the stencil printing apparatus 1 will be described. The operation of each unit described below is based on the control of the control unit 90 . First, a series of processes from performing stencil printing on the paper P supplied by the stencil printing apparatus 1 to discharging the printed printing paper P ′ will be described. On the display unit 70, predetermined information related to stencil printing is input by the operator. Specifically, the operator inputs information on the print density, such as the printing pressure of the press roller and the size of the perforations during plate making, information on the printing speed (rotation speed of the printing drum), and information on the type of ink used. Is done. The operator also inputs a desired number of printed sheets and the number of copies to be printed.

  Then, a document is placed on the document table 11 and image data is read by the line image sensor 13 while being pressed by the pressing plate 12. Then, plate making data is generated based on the image data read by the document reading unit 10, and the generated plate making data is output to the plate making unit 20. Then, the plate making unit 20 makes a plate based on the inputted plate making data and density information such as the size of perforations inputted by the operator.

  Specifically, a stencil sheet M having a length corresponding to a predetermined stencil sheet is fed out from a stencil sheet roll installed in a master holder in the stencil sheet roll unit 21. Then, based on the inputted plate making data and density information, a plurality of heating elements of the thermal head of the plate making unit 22 are selectively heated individually to produce heat-sensitive perforated plate, and a pre-made stencil sheet M is created. Is done.

  The pre-made stencil sheet M is sent out by the base paper feed rollers 23 and 24, cut by the base paper cutter 26 and wound around the printing drum 31. Ink is supplied to the ink receiving portion R by the ink supply means 34. The printing drum driving means 37 rotates the printing drum 31 in the direction of arrow C in FIG.

  After the printing paper P is fed from the paper feed table 41 by the primary paper feed roller 42 at a predetermined timing in synchronization with the rotation of the print drum 31, and once forms a slack in contact with the secondary paper feed roller 43, At a predetermined timing, the paper is conveyed from the left to the right in FIG. 1 by the secondary paper feed roller 43 and supplied between the printing drum 31 and the press roller 35. The press roller 35 presses the printing paper P against the stencil stencil sheet M so that stencil printing is performed on the printing paper P.

  When the printing drum 31 rotates by a predetermined angle and the stencil printing on one printing paper P is completed, the printed printing paper P ′ is peeled off from the printing drum 31 by the peeling claw 51, and the printing drum 31. The printed printing paper P ′ peeled off from the paper is conveyed to the paper discharge tray 53 by the paper discharge feed belt portion 52 and stacked on the paper discharge tray 53.

  Next, a series of processes for supplying consumed ink will be described. The ink in the ink reservoir AI is supplied to the printing drum 31 via the squeegee roller 32 and consumed. When ink is consumed and the ink sensor 81 does not output an ink detection signal, the ink supply means 34 starts supplying ink to the ink receiving portion R in order to supplement the consumed ink, and the ink detection signal Ink supply is stopped in response to re-input.

  Specifically, when the tip of the detection probe 811 inserted in the ink reservoir AI is separated from the ink reservoir AI, the ink detection signal is not output from the ink sensor 81, and the ink supply means 34 removes the ink in the ink bottle 341. The ink distributor 342 discharges the ink from the plurality of discharge ports 343 toward the ink receiving portion R. As the squeegee roller 32 and the ink driving rod 36 rotate, the ink ejected from the ejection port 343 is extended in the direction of the rotation axis of the ink driving rod 36. When the amount of ink in the ink reservoir AI increases and the tip of the detection probe 811 comes into contact with the ink reservoir AI and an ink detection signal is output from the ink sensor 81, the ink supply means 34 stops ink ejection.

  Next, a series of processing after detection from the detection of ink amount deviation will be described with reference to FIG. The ink monitor 82 monitors the ink detection signal from the ink sensor 81 to detect a deviation in the ink amount (ST1). If the deviation of the ink amount is not detected, the printing is continued as it is, and if it is detected, the ink sensor 81 in which the state where the ink detection signal is not output for a predetermined time continuously occurs is the same ink sensor 81 as the previous time. Whether or not is determined (ST2). In the case of the same ink sensor 81 as the previous time, the ink supply is stopped. Then, while the printing drum driving unit 37 rotates the printing drum 31, the paper feeding unit 40 stops feeding the paper P (hereinafter referred to as idling operation) (ST3). In the idling operation, since the paper P is not fed, the press contact by the press roller 35 is not performed.

  After the idling operation is performed for about 3 to 30 seconds, the ink is supplied and the idling operation is performed for about 5 to 60 seconds (ST4). The ink deviation detection unit 80 checks whether or not ink detection signals have been output from all the ink sensors 81 (ST5). When all the ink detection signals are not output, the display unit 70 displays a warning for prompting replacement of the ink bottle 341 (ST6). If all the ink detection signals have been output, the paper feed unit 40 resumes printing by resuming the feeding of the paper P (ST7).

  Next, a second embodiment of the stencil printing apparatus 1 will be described. The second embodiment is characterized in that plate-making data is used for detection of ink deviation. Other points of the second embodiment are the same as those of the first embodiment, and description thereof will be omitted, and only differences will be described. In addition, the same code | symbol is attached | subjected and demonstrated about the same structure and effect | action as 1st Embodiment.

  In the second embodiment, the ink deviation detection unit 80 includes a perforation rate calculation unit 83 as shown in FIG. The perforation rate calculating means 83 receives the platemaking data from the document reading unit 10 and corresponds to a plurality of regions virtually divided in the ink drum AI stored in the ink receiving unit R in the rotation axis direction of the printing drum 31. The perforation rate is calculated for each of a plurality of blocks obtained by dividing the base paper M in the main scanning direction. Then, the perforation rate calculating means 83 detects a case where the difference between the minimum perforation rate and the maximum perforation rate in the perforation rate of each block exceeds a threshold value as a deviation in the ink amount. This threshold is set according to the printing cycle.

  The perforation rate calculating means 83 may set a threshold value of a difference between the minimum perforation rate and the maximum perforation rate between 10 and 100.

In the second embodiment, the ink bias detecting unit 80, as shown in FIG. 7, with the temperature Dose capacitors 84 for detecting the temperature in the printing drum 31, the perforation rate calculating means 83, the printing drum 31 The difference between the minimum perforation rate and the maximum perforation rate in the perforation rate of each block that exceeds the threshold may be detected as a deviation in ink amount.

  Since the viscosity of ink increases in a low temperature environment, it may take time for the ink reservoir AI to extend in the direction of the rotation axis of the printing drum 31 even when the ink driving rod 36 rotates. Therefore, the punching rate calculation means 83 is, for example, in a low temperature environment where the temperature in the printing drum 31 is 5 to 15 ° C. or less, and the difference between the minimum punching rate and the maximum punching rate in the punching rate of each block is a threshold value. The case of exceeding may be detected as a deviation of the ink amount.

  A series of processes after the ink amount deviation is detected from the detection of the ink amount deviation in the second embodiment will be described with reference to FIG. The perforation rate calculating means 83 of the ink deviation detecting unit 80 receives the plate making data from the document reading unit 10, calculates the perforation rate for each of a plurality of blocks, and detects the ink amount deviation (ST1). If the deviation of the ink amount is not detected, the printing is continued as it is, and if it is detected, the ink is supplied and the idling operation is performed for about 5 to 60 seconds (ST4). The ink deviation detection unit 80 checks whether or not ink detection signals have been output from all the ink sensors 81 (ST5). When all the ink detection signals are not output, the display unit 70 displays a warning for prompting replacement of the ink bottle 341 (ST6). When all the ink detection signals are output, the paper feed unit 40 resumes paper feed, thereby resuming printing, printing a predetermined number of sheets, and ending the processing (ST7). In the second embodiment, as long as the plate-making data is not changed, the idling operation and printing for a predetermined number of sheets after idling are repeated.

  Next, a third embodiment of the stencil printing apparatus 1 will be described. The third embodiment is characterized in that the processing after detecting the deviation of the ink amount. Other points of the third embodiment are the same as those of the first or second embodiment, and description thereof will be omitted, and only differences will be described in detail. In addition, the same code | symbol is attached | subjected and demonstrated about the same structure and effect | action as 1st or 2nd embodiment.

  A series of processing after detection from detection of ink amount deviation in the third embodiment will be described with reference to FIG. The deviation of the ink amount is detected by the method of the first or second embodiment (ST1). If the deviation of the ink amount is not detected, the printing is continued as it is, and if it is detected, the idling operation is performed until the printing drum 31 rotates a predetermined number of revolutions, for example, 2 to 5 (ST8). In response to the next rotation in which the paper feeding unit 40 has performed an idling operation, paper P is fed and printing is resumed (ST7). That is, in the third embodiment, the paper feeding unit 40 performs intermittent paper feeding after detecting a deviation in the ink amount by the method of the first or second embodiment, and is applicable to both embodiments. .

  In the third embodiment, the rotational speed of the printing drum 31 during the idling operation is increased to about 1.1 to 2 times the rotational speed of the printing drum 31 during printing. Note that it is also possible to apply the rotational speed of the printing drum 31 during the idling operation to be higher than the rotational speed of the printing drum 31 during the printing in the first and second embodiments.

  According to the above-described embodiment, when the ink deviation detection unit 80 detects the deviation of the ink amount, printing is interrupted by idling for a predetermined time, and thus it is possible to prevent the occurrence of wrinkles in the printed image. Further, an increase in cost due to switching of the supply path can be avoided.

  Further, according to the above-described embodiment, the plurality of ink sensors 81 detect the ink reservoir AI for each of the plurality of regions, and the ink monitor 82 continuously has a state of less than the predetermined amount for a predetermined time in at least one region within the predetermined period. Thus, by detecting the case where the state less than the predetermined amount for a predetermined time does not occur in other regions other than at least one region, the deviation of the ink amount can be accurately detected.

  Further, according to the above-described embodiment, the punching rate calculation means 83 calculates the punching rate for each block of the stencil sheet corresponding to each region using the plate making data, and the minimum punching rate in the punching rate of each block By detecting the case where the difference from the maximum perforation rate exceeds the threshold as the ink amount deviation, the ink amount deviation can be predicted and detected.

  Further, according to the above-described embodiment, since the perforation rate calculating unit 83 detects the ink amount deviation when the inside of the printing drum 31 is equal to or lower than the predetermined temperature, the ink amount deviation is predicted in consideration of the low temperature environment. it can. Further, according to the above-described embodiment, after detecting the deviation of the ink amount, the paper feeding unit 40 performs intermittent paper feeding, so that printing can be continued with a longer printing cycle.

AI Ink pool M Stencil sheet R Ink receiving section 31 Printing drum 32 Squeegee roller 33 Doctor roller 34 Ink supply means 37 Printing drum drive means 40 Paper feed section 80 Ink deviation detection section 90 Control section

Claims (4)

A rotatable printing drum around which stencil paper is wound,
Printing drum driving means for rotationally driving the printing drum;
Paper feeding means for feeding paper toward the printing drum according to the rotation of the printing drum;
A squeegee roller inscribed in the printing drum;
A doctor roller which is arranged in the vicinity of the squeegee roller and forms an ink receiving portion extending in the rotation axis direction of the printing drum with the squeegee roller;
Ink supply means for supplying ink to the ink receiver;
Ink bias for detecting a predetermined deviation of the ink amount between a plurality of areas obtained by partitioning the ink reservoir stored in the ink receiving portion in the rotation axis direction of the printing drum as the deviation of the ink amount during the rotation of the printing drum. Detection means;
Control for controlling the printing drum driving means and the paper feeding means to stop the paper feeding while rotating the printing drum when the ink deviation detecting means detects the ink amount deviation. and means,
The ink deviation detecting means includes a sensor that detects whether or not the amount of ink in each of the regions is equal to or greater than a predetermined amount, and based on the output of the sensor, the ink bias detection means is less than the predetermined amount for a predetermined time in at least one region The ink amount is biased when the state is continuously generated within a predetermined period and the state less than the predetermined amount for the predetermined time does not occur in other regions other than the at least one region. A stencil printing machine. A rotatable printing drum around which stencil paper is wound,
Printing drum driving means for rotationally driving the printing drum;
Paper feeding means for feeding paper toward the printing drum according to the rotation of the printing drum;
A squeegee roller inscribed in the printing drum;
A doctor roller which is arranged in the vicinity of the squeegee roller and forms an ink receiving portion extending in the rotation axis direction of the printing drum with the squeegee roller;
Ink supply means for supplying ink to the ink receiver;
Ink bias for detecting a predetermined deviation of the ink amount between a plurality of areas obtained by partitioning the ink reservoir stored in the ink receiving portion in the rotation axis direction of the printing drum as the deviation of the ink amount during the rotation of the printing drum. Detection means;
Control for controlling the printing drum driving means and the paper feeding means to stop the paper feeding while rotating the printing drum when the ink deviation detecting means detects the ink amount deviation. Means and
The ink deviation detecting means calculates a perforation rate for each block of the stencil sheet corresponding to each region using the plate making data of the stencil sheet, and the minimum perforation rate and the maximum perforation rate in the perforation rate of each block When the difference between the two exceeds a threshold value, the ink amount is biased.
When the ink bias detection unit detects the ink amount bias, the control unit stops feeding the paper until the printing drum rotates a first predetermined number of times, and after the first predetermined number of rotations The paper is fed in response to the second predetermined number of rotations of the paper, and thereafter, the paper feeding is stopped until the first predetermined number of rotations, and after the first predetermined number of rotations, the paper is fed in response to the second predetermined number of rotations. hole plate printing device you characterized in that said printing drum drive means so as to repeat the step of feeding the paper is intended to control the said feeding means Te. Temperature detecting means for detecting the temperature in the printing drum;
The ink deviation detecting means determines the deviation of the ink amount when the detected temperature is equal to or lower than a predetermined temperature and the difference between the minimum perforation ratio and the maximum perforation ratio exceeds a threshold in the perforation ratio of each block. The stencil printing apparatus according to claim 2 , wherein: When the ink bias detection unit detects the ink amount bias, the control unit stops feeding the paper until the printing drum rotates a predetermined number of times, and responds to the next rotation after the predetermined number of rotations. The printing drum driving means and the paper feeding means are controlled so as to repeat the process of feeding the paper, and then stopping the paper feeding until the predetermined number of rotations and refeeding after the predetermined number of rotations. The stencil printing apparatus according to claim 1, wherein:

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