JP2016137652A - Stencil printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make printing elongations of the entire stencil paper uniform even if printing elongations are different depending on regions of patterns of bored image portions thermally bored on the stencil paper.SOLUTION: A stencil printer (1) comprises at least a platemaking unit (30), a sheet feeding unit (50), a printing unit (60) and a control unit (95). The control unit (95) divides stencil paper M into at least two or more divided regions Ma11, Ma12 with a division line B set along the rotation direction of a plate cylinder 61, and thermally bores printing elongation adjustment holes Mn11, Mn12 at portions where ink (IK) does not oozes on the stencil paper M so that respective boring ratios α11, α12 calculated in the respective divided regions Ma11, Ma12 become equal.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a stencil printing apparatus that prints an image on a sheet through a stencil sheet wound around an outer peripheral surface of a cylindrical plate cylinder, and the stencil is formed by a pattern area of a perforated image portion that is thermally perforated on the stencil sheet. The present invention relates to a stencil printing apparatus capable of making the printing elongation of the entire stencil base paper uniform even if the printing elongation in the longitudinal direction of the base paper is different.

  In general, a stencil printing apparatus clamps a stencil sheet that has been made by a clamp plate provided in a part of the outer peripheral surface of a rotatable plate cylinder (drum) so that it can be opened and closed. It is wound along the surface.

  A perforated image portion in which the ink supplied into the plate cylinder is thermally perforated on the stencil base paper while pressing the paper fed from the paper feeding section to the stencil base side with a press roller provided so as to be able to contact and separate from the plate cylinder The image corresponding to the perforated image portion of the stencil sheet is printed on the paper, and then the printed paper is peeled off from the plate cylinder side by a peeling claw placed close to the plate cylinder and discharged. By discharging to the center, a large number of identical images can be printed with one stencil sheet, which is often used.

  For stencil paper applied to this type of stencil printing apparatus, the present applicant has previously proposed a stencil base paper that can suppress the elongation at the time of printing the base paper at the time of printing a large number of sheets (for example, Patent Documents). 1).

  The stencil printing paper disclosed in Patent Document 1 is formed by laminating a thermoplastic resin film and a porous support mainly composed of synthetic fibers.

This stencil printing base paper has a wet tensile strength in the longitudinal direction of the base paper set to 200 gf / cm or more, and a shear breaking strength in the longitudinal direction of the base paper is set to 400 gf / cm ² or more, thereby printing a large number of sheets. The printing elongation in the longitudinal direction of the base paper at the time can be suppressed, and the occurrence of printing wrinkles can be prevented. As a result, it is possible to obtain a clear printed material with excellent document reproducibility.

JP 2001-10247 A

  By the way, in the stencil printing paper described in Patent Document 1, as described above, by setting the mechanical properties (wet tensile strength, shear fracture strength) of the stencil sheet itself, in the longitudinal direction of the stencil sheet when printing a large number of sheets. Improvement has been made so as to suppress the printing elongation.

  However, the base paper generally has a perforated image portion perforated according to the pattern of the image to be printed on the paper using a thermal head. At this time, since the perforation ratio of the perforated image part differs depending on the pattern area of the perforated image part thermally perforated on the base paper, it was found that the printing elongation in the longitudinal direction of the base paper differs depending on the pattern area on the base paper. .

  The above-described difference in printing elongation due to the pattern area on the base paper is not considered in Patent Document 1, and therefore improvement is desired. Also, mechanical properties of the base paper itself (wet tensile strength, shear fracture strength) ), It is desired to make the printing elongation of the entire stencil sheet uniform even if a stencil sheet in which a resin film and Japanese paper are superposed is used.

  Therefore, the present invention provides a stencil printing apparatus capable of uniformizing the printing elongation of the entire stencil sheet even if the printing elongation in the longitudinal direction of the stencil sheet differs depending on the pattern area of the perforated image portion thermally perforated on the stencil sheet. For the purpose.

The present invention has been made in view of the above problems, and a plate making unit for making a stencil sheet for one plate by thermally punching a punched image portion on the stencil sheet,
A paper feed unit for feeding paper one by one;
The stencil sheet for one plate made by the plate making unit is wound around an outer peripheral surface of a rotatable plate cylinder, and the ink oozed from the outer peripheral surface of the plate cylinder is sent from the paper feeding unit. A printing unit that prints an image corresponding to a perforated image portion of the stencil sheet for one plate on paper;
In a stencil printing apparatus comprising at least a control unit for controlling the entire apparatus,
The control unit divides the stencil sheet into at least two or more divided areas by a dividing line set along the rotation direction of the plate cylinder, and print elongation adjusting holes are formed in a portion where the ink does not bleed on the stencil sheet. The stencil printing apparatus is characterized in that thermal perforation is performed so that the perforation rates calculated in each divided region are equal.

  According to the stencil printing apparatus according to the present invention, in the stencil printing apparatus including at least a plate making unit, a paper feeding unit, a printing unit, and a control unit, the control unit is set along the rotation direction of the plate cylinder. The stencil sheet is divided into at least two or more divided regions by dividing lines, and the print elongation adjusting holes are thermally perforated so that the calculated perforation ratios in the divided regions are equal to the portions where the ink does not bleed on the stencil sheet. ing.

  As a result, even if the printing elongation in the longitudinal direction of the stencil sheet differs depending on the pattern area of the perforated image part that has been thermally perforated on the stencil sheet, the printing elongation adjustment holes are divided into portions where ink does not bleed on the stencil sheet. By performing thermal perforation so that the perforation rates calculated in the region are equal, the printing elongation of the entire stencil sheet can be made uniform, so that an image without image distortion can be printed on the paper in the printing unit.

1 is an overall configuration diagram showing an overall configuration of a stencil printing apparatus according to the present invention. (A), (b) is the top view and longitudinal cross-sectional view which showed the printing elongation adjustment hole which carried out the thermosensitive punching on the stencil paper in Example 1. FIG. (A), (b) is a figure for demonstrating the state which detects the presence or absence of the stencil paper on the plate cylinder in Example 1. FIG. (A), (b) is the top view and longitudinal cross-sectional view which showed the printing elongation adjustment hole which carried out the heat-sensitive punching on the stencil paper in Example 2. FIG. (A), (b) is a figure for demonstrating the state which detects the presence or absence of the stencil paper on the plate cylinder in Example 2. FIG.

  Hereinafter, an embodiment of a stencil printing apparatus according to the present invention will be described in detail with reference to FIGS.

  FIG. 1 shows the overall configuration of a stencil printing apparatus according to the present invention.

  As shown in FIG. 1, in the stencil printing apparatus 1 according to the present invention, an apparatus housing 2 that forms the appearance of the apparatus 1 is formed in a box shape.

  The stencil printing apparatus 1 described above includes an operation panel unit 10 for operating the apparatus 1, a document reading unit 20 for reading a document G on which image information such as images and characters is described, and a document G read by the document reading unit 20. On the outer peripheral surface 61a of the plate cylinder 61 of the printing cylinder 60 described later. A cam drive unit 40 that opens and closes a clamp plate 66 that can be opened and closed in part, a paper feed unit 50 that feeds unprinted paper P one by one, and a clamp on an outer peripheral surface 61a of a rotatable plate cylinder 61 A stencil sheet M for one plate is wound through a plate 66 to print unprinted paper P, a paper discharge unit 80 for discharging printed paper P, and a plate cylinder 61 side. To remove used stencil paper M 90, is schematically constituted by a control unit 95 that performs overall control of the printer 1.

  Here, each part in the stencil printing apparatus 1 will be specifically described in order.

  First, the operation panel unit 10 is installed on the left side (or front surface) of the top surface 2 a of the apparatus housing 2. Although not shown in detail, the operation panel unit 10 includes various function buttons for performing a print job, a numeric keypad, a liquid crystal display panel, and the like.

  In the operation panel unit 10, the user operates each unit by operating various function buttons.

  Next, the document reading unit 20 is installed on the top surface 2 a of the apparatus housing 2. The document reading unit 20 includes a document table 21 on which a document G on which image information is described, a light reflection type sensor 22 that detects the presence or absence of the document G, a plurality of document conveyance roller pairs 23, and a document G. A CCD image sensor 24 for reading the image information and a document discharge table 25 are provided.

  In the document reading unit 20, the image information of the document G is read by the CCD image sensor 24 while the document G is fed by the plurality of document conveying roller pairs 23, and then the read image information is sent to the plate making unit 30.

  Next, the plate making unit 30 is installed at an upper right portion in the apparatus housing 2. The plate making unit 30 includes a base paper storage unit 31 that stores a stencil paper (master) M that is wound in a roll and overlaps a resin film and Japanese paper, and is disposed downstream of the base paper storage unit 31 and is a stencil A thermal head 32 for thermally perforating the base paper M, a platen roller 34 arranged to be rotatable by a platen motor 33 so as to face the thermal head 32, and a base paper feed arranged downstream of the thermal head 32 and the platen roller 34 A roll pair 35 and a base paper cutter pair 36 disposed downstream of the base paper feed roll pair 35 are provided.

  In the plate making unit 30, the thermal head 32 and the platen roller 34 sandwich and convey the stencil sheet M, and based on the image information read by the document reading unit 20 on the resin film of the stencil sheet M by the thermal head 32. The perforated image portion Mg (FIGS. 2 and 4) is thermally perforated. Further, as will be described later, even if the printing elongation in the longitudinal direction of the stencil sheet M differs depending on the pattern area of the perforated image portion Mg that is thermally perforated on the stencil sheet M, in order to uniformly adjust the printing elongation of the entire stencil sheet M The printing elongation adjusting hole Mn (FIGS. 2 and 4) is thermally perforated.

  The perforated image portion Mg (FIGS. 2 and 4) may be thermally perforated on the stencil sheet M based on image information from a personal computer (not shown).

  Thereafter, the stencil sheet M in which the perforated image portion Mg and the print elongation adjusting hole Mn are thermally perforated is cut by the base paper cutter pair 36 into a size corresponding to the maximum size of the sheet P, for example, A3 size (420 mm × 297 mm). After the stencil sheet M for one plate is made, the stencil sheet M that has been subjected to the plate making process is conveyed toward the plate cylinder 61 in the printing unit 60.

  Next, although detailed illustration is omitted here, the cam drive unit 40 is installed close to the upper part of the plate cylinder 61 in the printing unit 60 and the downstream of the plate making unit 30, and the stencil plate for one plate. A cam (not shown) for opening the clamp plate 66 attached to a part of the outer peripheral surface 61a of the plate cylinder 61 is driven when the base paper M is put on the plate cylinder 61.

  Next, the paper feed unit 50 is installed on the left side surface 2 b side of the apparatus housing 2. The paper feed unit 50 uses a gear train 53 to rotate the paper feed motor 52 to feed a plurality of unprinted paper sheets P and a paper sheet 51 stacked on the paper feed base 51. A paper feeding roller 54 and a rolling roller 55 which are decelerated and rotated in the paper feeding direction, a winding plate 56 which is disposed so as to face the winding roller 55, and a resist which is disposed downstream of the winding roller 55 and the rolling plate 56. And a roller pair 57.

  In the paper feeding unit 50, the paper P of the uppermost layer among the plurality of papers P stacked on the paper feed tray 51 is pressed against the uppermost paper P while being rotated, and the upper paper P is taken out.

  Thereafter, the paper P taken out by the paper feeding roller 54 is separated one by one when being nipped and conveyed between the paper roller 55 and the paper plate 56, and is fed toward the downstream registration roller pair 57. Has been. Here, the registration roller pair 57 corrects the skew of the paper P by abutting the paper P while the rotation is stopped to form a loop, and then rotates at a predetermined timing to print the paper P downstream. Sent to department 60.

  Next, the printing unit 60 is installed at a substantially central portion in the apparatus housing 2. In this printing unit 60, the plate cylinder 61 is formed in a cylindrical shape with an outer diameter φD of about 180 mm corresponding to a length dimension 420 mm of an A3 size paper P, for example, and the short direction of the A3 size paper P The axial direction is formed to be long corresponding to the dimension 297 mm.

  The plate cylinder 61 is rotationally driven by the plate cylinder motor 63 around the center shaft 62 at a speed of one rotation (10 rpm) in 6 seconds in the illustrated counterclockwise direction. An ink insertion opening 62a for inserting the ink IK is formed on one end surface side of the central shaft 62 of the plate cylinder 61.

  The plate cylinder motor 63 described above is a geared motor with a built-in reduction gear. An encoder 64 is attached to a rear end shaft portion (not shown) of the plate cylinder motor 63, and the plate cylinder 61 is rotated by the encoder 64. Pulses indicating the rotation angle at this time are sequentially output.

  A plate mounting table 65 is fixed to a part of the outer peripheral surface 61a of the plate cylinder 61, and a clamp plate 66 for clamping the stencil sheet M for one plate is mounted on the plate mounting table 65 so as to be opened and closed. ing.

  At this time, the outer peripheral surface 61a of the plate cylinder 61 is a portion where the ink IK does not bleed out at the front and rear portions of the plate mounting base 65, and the ink IK oozes except for the front and rear portions of the plate mounting base 65. It has porosity.

  Further, a reflective material 67 is attached to a portion of the outer peripheral surface 61 a of the plate cylinder 61 where the ink IK on the downstream side in the rotation direction from the plate mounting base 65 does not bleed out and at a substantially central portion in the axial direction of the plate cylinder 61. ing.

  Further, a light reflection type sensor 68 is installed on the outer side of the outer peripheral surface 61a of the plate cylinder 61 corresponding to the position of the reflecting material 67 when the plate mounting base 65 on the plate cylinder 61 reaches the upper side. The light reflection type sensor 68 includes an irradiation unit (not shown) that irradiates light toward the reflecting material 67 attached to the outer peripheral surface 61 a of the plate cylinder 61 and a light receiving unit that receives the light reflected by the reflecting material 67. (Not shown). The presence of the stencil sheet M on the outer peripheral surface 61a of the plate cylinder 61 can be detected by the reflective material 67 and the light reflection type sensor 68. The detection of the presence of the stencil sheet will be described in detail later.

  A doctor roller 69 and an ink roller 70 are rotatably provided below the inside of the plate cylinder 61 while being in contact with each other. Further, the ink IK supplied from the center shaft 62 of the plate cylinder 61 is accumulated between the doctor roller 69 and the ink roller 70, and this ink IK passes through the gap between the doctor roller 69 and the ink roller 70 and this ink IK. The stencil sheet M wound around the outer peripheral surface 61 a of the plate cylinder 61 is supplied from the outer peripheral surface of the roller 70.

  A press roller 71 is provided below the plate cylinder 61 so as to be able to contact and separate with a predetermined pressing force against the outer peripheral surface 61a of the plate cylinder 61 by a not-shown press roller contact / separation mechanism.

  The press roller 71 is separated from the outer peripheral surface 61a when the clamp plate 66 provided on a part of the outer peripheral surface 61a passes downward as the plate cylinder 61 rotates.

  Further, on the lower right side of the plate cylinder 61, a peeling claw 72 is installed close to the outer peripheral surface 61 a of the plate cylinder 61. The peeling claw 72 has a function of peeling the paper P printed by the printing unit 60 from the outer peripheral surface 61 a side of the plate cylinder 61.

  In the printing unit 60, the plate cylinder 61 starts to rotate counterclockwise from the plate cylinder reference position set in the upper right part, and is attached to a part of the outer peripheral surface 61a of the plate cylinder 61 so as to be opened and closed. When 66 reaches the upper plate-making position, the clamp plate 66 is opened by the cam driving unit 40 to clamp the stencil sheet M that has been made from the plate-making unit 30 and is sent from the plate-making unit 30.

  Thereafter, while the plate cylinder 61 is rotated, the reflection state from the reflecting material 67 attached to the outer peripheral surface 61a of the plate cylinder 61 is detected by the light reflection sensor 68, and the presence of the stencil sheet is detected via the control unit 95. When the plate cylinder 61 is rotated counterclockwise, the stencil sheet M for one plate is wound along the outer peripheral surface 61 a of the plate cylinder 61.

  Then, after the clamp plate 66 that clamps the stencil sheet M passes through the press roller 71, the unprinted paper P sent from the paper supply unit 50 by the press roller 71 is wound around the outer peripheral surface 61 a of the plate cylinder 61. The ink IK supplied to the plate cylinder 61 while being pressed against the stencil sheet M and transported the sheet P toward the downstream side passes through the stencil sheet M and corresponds to the perforated image portion of the stencil sheet M on the sheet P. The image is printed.

  Next, the paper discharge unit 80 is installed on the right side surface 2 c side of the apparatus housing 2. The paper discharge unit 80 includes a paper discharge roller pair 81 that discharges the printed paper P and a paper discharge tray 82 that stacks the printed paper P.

  In the paper discharge section 80, the printed paper P is peeled off from the plate cylinder 61 side by the peeling claw 72 and discharged onto the paper discharge tray 82 via the paper discharge roller pair 81.

  Next, the plate removal unit 90 is installed in the upper left part of the plate cylinder 61 in the apparatus housing 2. In the plate discharging unit 90, the used stencil sheet M peeled from the outer peripheral surface 61a of the plate cylinder 61 is stored in a plate discharging box (not shown).

  Next, the control unit 95 is installed at an appropriate position in the apparatus housing 2. The control unit 95 calculates and processes the punching rate α (FIGS. 2 and 4) thermally perforated on a stencil sheet M, which will be described later, and determines whether or not the stencil sheet M is present. The number of pulses output from the ROM 95b storing the operation program, the RAM 95c that temporarily stores various information that can be changed in the stencil printing apparatus 1, and the encoder 64 attached to the plate cylinder motor 63 is counted. It has a counter 95d inside.

  Then, the control unit 95 includes the operation panel unit 10, the document reading unit 20, the plate making unit 30, the cam driving unit 40, the paper feeding unit 50, the printing unit 60, the paper discharge unit 80, and the plate discharging unit 90. And control each.

  Using the stencil printing apparatus 1 configured as described above, on the paper P corresponding to the perforated image portion Mg (FIGS. 2 and 4) on the stencil sheet M wound around the outer peripheral surface 61 a of the plate cylinder 61. When printing an image, as described above in the background art, the perforation rate α (FIGS. 2 and 4) of the perforated image portion Mg depends on the pattern area of the perforated image portion Mg thermally perforated on the stencil sheet M. Therefore, it has been found that the printing elongation in the longitudinal direction of the stencil sheet M differs depending on the pattern area on the stencil sheet M.

  Therefore, in the present invention, in order to make the printing elongation of the entire stencil sheet uniform, measures are taken in the first and second embodiments. Hereinafter, the first and second embodiments will be described.

[Example 1]
FIGS. 2A and 2B show printing elongation adjusting holes which are heat-sensitively punched on the stencil sheet in Example 1. FIG.

  As shown in FIGS. 2 (a) and 2 (b), the stencil sheet M in Example 1 is formed by superposing a resin film F and a Japanese paper W, and the resin film F side is the plate making portion 30 (FIG. 1). Thermal punching is performed by the thermal head 32, and the side of the Japanese paper W is in contact with the outer peripheral surface 61a of the plate cylinder 61 without thermal punching.

  On the stencil sheet M, the front end side of the outer peripheral surface 61a of the plate cylinder 61 corresponding to a part on the downstream side in the rotational direction from the plate mounting base 65 is a portion where the ink IK does not bleed out. The part that oozes out is an area for printing an image.

  Here, when the perforated image portion Mg is thermally perforated on the stencil sheet M by the thermal head 32 of the plate making unit 30, a dividing line B is set along the rotation direction of the plate cylinder 61, and the dividing region Ma is defined by the dividing line B. Are divided into at least two pieces in the width direction of the base paper with the same area.

  In the first embodiment, the stencil sheet M is divided into, for example, first and second divided areas Ma11 and Ma12 by a dividing line B set at a half width position (center position) in the width direction of the base paper.

  When the first and second perforated image portions Mg11 and Mg12 are thermally perforated in the first and second divided regions Ma11 and Ma12, the CPU 95a in the control unit 95 is divided into the first and second regions divided by equal areas. First and second perforation rates α11 and α12 indicating the ratio of the first and second perforated image portions Mg11 and Mg12 to the second divided regions Ma11 and Ma12 are calculated.

  The “puncture rate α” means the ratio of the number of puncture pixels in each of the puncture image portions Mg11 and Mg12 to the total number of pixels in each of the divided areas Ma11 and Ma12.

  At this time, in the first and second divided regions Ma11 and Ma12, the areas of the first and second punched image portions Mg11 and Mg12 are, for example, first punched image portion Mg11> second punched image portion Mg12. Assuming that, the perforation rate α is such that the first perforation rate α11> the second perforation rate α12.

  Accordingly, the printing elongation in the longitudinal direction of the stencil sheet M in the first divided area Ma11 having a large value of the first perforation ratio α11 is larger than the printing elongation in the second divided area Ma12 having a small value of the second perforation ratio α12. Therefore, it becomes necessary to make the printing elongation of the entire stencil sheet uniform.

  Therefore, the first and second printing elongation adjusting holes Mn11 and Mn12 are thermally perforated in each part of the first and second divided areas Ma11 and Ma12 where the ink IK from the plate cylinder 61 does not bleed out. In Example 1, the first and second printing elongation adjusting holes Mn11 and Mn12 are thermally perforated on the resin film F on the side clamped by the clamp plate 66.

  At this time, the first printing elongation adjusting hole Mn11 in the first divided region Ma11 having a large printing elongation is set to have a smaller punching area than the second printing elongation adjusting hole Mn12 in the second dividing region Ma12 having a small printing elongation. Thus, the first total perforation ratio obtained by summing the first perforated image portion Mg11 and the first print elongation adjusting hole Mn11 in the first divided region Ma11 and the second perforated image portion Mg12 in the second divided region Ma12. The first and second print elongation adjusting holes Mn11 and Mn12 are formed so that the second total perforation rate obtained by summing the second print elongation adjusting holes Mn12 and the second print elongation adjusting holes Mn12 is equal.

  In other words, the perforated areas of the first and second print elongation adjusting holes Mn11 and Mn12 are thermally perforated so as to be inversely proportional to the first and second perforation rates α11 and α12.

  As a result, even if the printing elongation in the longitudinal direction of the stencil sheet M varies depending on the pattern area of the perforated image portion Mg thermally perforated on the stencil sheet M, the first ink IK does not bleed out on the stencil sheet M. The second printing elongation adjusting holes Mn11 and Mn12 are heat-sensitive perforated so that the total perforation ratios calculated in the first and second divided areas Ma11 and Ma12 are equal, so that the printing elongation of the entire stencil sheet can be made uniform. Therefore, an image without image distortion can be printed on the paper P by the printing unit 60.

  In the first embodiment, the first and second printing elongation adjusting holes Mn11 and Mn12 are thermally perforated in the first and second divided areas Ma11 and Ma12 to uniform the printing elongation of the entire stencil sheet. However, the present invention is not limited to this, but printing elongation adjusting holes may be thermally perforated only in the second divided area Ma having a small perforation rate, although not shown here.

  Next, in Example 1, the presence or absence of the stencil sheet M on the plate cylinder 61 is detected when the first and second printing elongation adjusting holes Mn11 and Mn12 are thermally perforated on the stencil sheet M as described above. The operation will be described with reference to FIG.

  3A and 3B show a state in which the presence or absence of a stencil sheet on the plate cylinder in the first embodiment is detected.

  As shown in FIGS. 3A and 3B, as described above, the portion of the outer peripheral surface 61a of the plate cylinder 61 where the ink IK on the downstream side in the rotation direction from the plate mounting base 65 does not bleed out and this plate. A reflector 67 is attached to a substantially central portion of the body 61 in the axial direction. Further, a light reflection type sensor 68 is installed on the outer side of the outer peripheral surface 61 a of the plate cylinder 61 so as to face the reflecting material 67.

  When the stencil sheet M is not wound on the outer peripheral surface 61 a of the plate cylinder 61, the light from the irradiation part of the light reflection type sensor 68 is reflected by the reflecting material 67. Thereafter, since the light reflected by the reflecting material 67 is received by the light receiving portion of the light reflecting sensor 68, the amount of light received by the light receiving portion of the light reflecting sensor 68 is larger than that of the antireflection piece described above in the background art. The CPU (determination unit) 95a of the control unit 95 can detect the absence of stencil paper.

  On the other hand, when the stencil sheet M is wound on the outer peripheral surface 61a of the plate cylinder 61, the central part of the stencil sheet M corresponding to the reflector 67 in the width direction of the base sheet is the resin film F and the Japanese paper W. Therefore, the light from the light reflecting sensor 68 is reflected by the resin film F of the stencil sheet M, and some irregular reflection is caused by the resin film F. Therefore, the output voltage from the light reflecting sensor 68 is rippled. Although the value is low, there is a sufficient voltage difference with respect to the case of no stencil sheet, so the CPU (determination unit) 95a of the control unit 95 can reliably detect the presence of the stencil sheet.

[Example 2]
4 (a) and 4 (b) show printing elongation adjusting holes which are heat-sensitive perforated on the stencil sheet in Example 2. FIG.

  As shown in FIGS. 4A and 4B, the stencil sheet M in Example 2 is also formed by superposing the resin film F and the Japanese paper W in the same manner as in Example 1, and the resin film F side is plate-making. Thermally perforated by the thermal head 32 of the section 30 (FIG. 1), and the Japanese paper W side comes into contact with the outer peripheral surface 61a of the plate cylinder 61 without being thermally perforated.

  On the stencil sheet M, the front end side of the outer peripheral surface 61a of the plate cylinder 61 corresponding to a part on the downstream side in the rotational direction from the plate mounting base 65 is a portion where the ink IK does not bleed out. The part that oozes out is an area for printing an image.

  Here, when the perforated image portion Mg is thermally perforated on the stencil sheet M by the thermal head 32 of the plate making unit 30, a dividing line B is set along the rotation direction of the plate cylinder 61, and the dividing region Ma is defined by the dividing line B. Are divided into at least two pieces in the width direction of the base paper with the same area.

  In the second embodiment, the first, second, and third divided areas Ma21, Ma22, Ma22 are formed on the stencil sheet M by the dividing lines B set at, for example, a position of 1/3 width and 2/3 width in the width direction of the base paper. Ma23 is divided into three.

  When the first, second, and third drilled hole image portions Mg21, Mg22, and Mg23 are thermally punched in the first, second, and third divided areas Ma21, Ma22, and Ma23, the CPU 95a in the control unit 95 , First, second and third indicating the ratio of the first, second and third perforated image portions Mg21, Mg22 and Mg23 to the first, second and third divided regions Ma21, Ma22 and Ma23, respectively divided by equal areas. The third perforation rates α21, α22, α23 are calculated.

  The “puncture rate α” means the ratio of the number of puncture pixels in each of the puncture image portions Mg21, Mg22, and Mg23 to the total number of pixels in each of the divided areas Ma21, Ma22, and Ma23.

  At this time, in each of the first, second, and third divided regions Ma21, Ma22, and Ma23, the areas of the first, second, and third punched image portions Mg21, Mg22, and Mg23 are, for example, the second punched image portion Mg22>. Assuming that the first perforation image portion Mg21> the third perforation image portion Mg23, it is assumed that the perforation rate α is second perforation rate α22> first perforation rate α21> third perforation rate α23.

  Along with this, the printing elongation in the second divided area Ma22 becomes the largest, then the printing elongation in the first divided area Ma21 continues, and the printing elongation in the third divided area Ma23 becomes the smallest, so the stencil sheet It is necessary to make the overall printing elongation uniform.

  Therefore, the first, second, and third print elongation adjusting holes Mn21, Mn22, and the like in the first, second, and third divided areas Ma21, Ma22, and Ma23, where the ink IK from the plate cylinder 61 does not bleed out. In this Example 2, the first, second, and third printing elongation adjusting holes Mn21, Mn22, and Mn23 were thermally perforated in the resin film F on the side clamped by the clamp plate 66. Yes.

  At this time, the perforated areas of the first, second, and third printing elongation adjusting holes Mn21, Mn22, and Mn23 are as follows: second printing elongation adjusting hole Mn22 <first printing elongation adjusting hole Mn21 <third printing elongation adjusting hole Mn23. The first total perforation rate obtained by summing the first perforated image portion Mg21 and the first print elongation adjusting hole Mn21 in the first divided area Ma21 and the second divided area Ma22 The second total perforation ratio obtained by summing the second perforated image portion Mg22 and the second print elongation adjusting hole Mn22, the third perforated image portion Mg23 and the second print elongation adjusting hole Mn23 in the third divided region Ma23, The first, second, and third printing elongation adjusting holes Mn21, Mn22, and Mn23 are formed so that the third total perforation rate obtained by summing the two becomes equal.

  In other words, the perforated areas of the first, second and third printing elongation adjusting holes Mn21, Mn22 and Mn23 are thermally perforated so as to be in inverse proportion to the first, second and third perforation rates α21, α22 and α23. ing.

  As a result, even if the printing elongation in the longitudinal direction of the stencil sheet M varies depending on the pattern area of the perforated image portion Mg thermally perforated on the stencil sheet M, the first ink IK does not bleed out on the stencil sheet M. , The second and third printing elongation adjusting holes Mn21, Mn22, and Mn23 are thermally perforated so that the total perforation ratios calculated in the first, second, and third divided regions Ma21, Ma22, and Ma23 are equal. Since the printing elongation of the entire stencil sheet can be made uniform, an image without image distortion can be printed on the paper P by the printing unit 60.

  Further, in the second embodiment, unlike the first embodiment, the second printing elongation adjusting hole Mn22 located at the center portion in the base paper width direction among the first, second and third printing elongation adjusting holes Mn21, Mn22 and Mn23. Is also used as a stencil sheet presence / absence detection hole.

  At this time, including the case where the stencil sheet M is divided into three by the dividing line B, the stencil sheet M is divided into the odd divided areas by the dividing line B, so that the center part of the odd numbered divided areas in the width direction of the base paper The printing elongation adjusting hole formed in the divided area located at the same position can also be used as the stencil sheet presence / absence detecting hole.

  Next, in Example 2, when the second printing elongation adjusting hole Mn22 that was thermally perforated on the stencil sheet M in the center portion in the width direction of the stencil sheet as described above was also used as the stencil sheet presence / absence detection hole, The operation for detecting the presence or absence of the stencil sheet M in FIG. 5 will be described with reference to FIG.

  5A and 5B show a state in which the presence or absence of a stencil sheet on the plate cylinder in Example 2 is detected.

  As shown in FIGS. 5A and 5B, as described above, the portion of the outer peripheral surface 61a of the plate cylinder 61 where the ink IK on the downstream side in the rotation direction from the plate mounting base 65 does not bleed out and this plate. A reflector 67 is attached to a substantially central portion of the body 61 in the axial direction. Further, a light reflection type sensor 68 is installed on the outer side of the outer peripheral surface 61 a of the plate cylinder 61 so as to face the reflecting material 67.

  When the stencil sheet M is not wound on the outer peripheral surface 61 a of the plate cylinder 61, the light from the irradiation part of the light reflection type sensor 68 is reflected by the reflecting material 67. Thereafter, since the light reflected by the reflecting material 67 is received by the light receiving portion of the light reflecting sensor 68, the amount of light received by the light receiving portion of the light reflecting sensor 68 is larger than that of the antireflection piece described in the background art. The value becomes large, and the CPU (determination unit) 95a of the control unit 95 can detect the absence of the stencil sheet.

  On the other hand, when the stencil sheet M is wound on the outer peripheral surface 61 a of the plate cylinder 61, the central part of the stencil sheet M corresponding to the reflector 67 in the width direction of the stencil sheet M corresponds to the resin film F. 2 Since the printing extension adjusting hole Mn22 is thermally perforated, the light from the light reflecting sensor 68 passes through the second printing extension adjusting hole Mn22 and is reflected by the Japanese paper W, so that the output from the light reflecting sensor 68 is output. Unlike the case of the first embodiment, the voltage is a low value without ripple, and the CPU (determination unit) 95a of the control unit 95 can more reliably detect the presence of the stencil sheet.

DESCRIPTION OF SYMBOLS 1 ... Stencil printing apparatus, 2 ... Apparatus housing, 2a ... Top surface, 2b ... Left side surface, 2c ... Right side surface,
DESCRIPTION OF SYMBOLS 10 ... Operation panel part, 20 ... Document reading part, 24 ... CCD image sensor,
30: Plate making section, 32 ... Thermal head, 33 ... Platen motor,
34 ... Platen roller, 36 ... Base paper cutter pair,
40: Cam drive unit, 50: Paper feed unit,
60 ... Printing section, 61 ... Plate cylinder, 61a ... Outer peripheral surface, 62 ... Center axis, 62a ... Ink insertion port,
63 ... Plate cylinder motor, 64 ... Encoder, 65 ... Plate mount, 66 ... Clamp plate,
67 ... reflecting material, 68 ... light reflecting sensor,
69 ... Doctor roller, 70 ... Ink roller, 71 ... Press roller, 72 ... Peeling nail,
80: paper discharge unit, 90: discharge unit, 95: control unit, 95a: CPU (determination unit),
G ... manuscript, IK ... ink, M ... stencil paper,
Ma ... divided area, Ma11, Ma12 ... first and second divided areas in the first embodiment,
Ma21, Ma22, Ma23 ... the first, second and third divided regions in the second embodiment,
Mg: perforated image portion, Mg11, Mg12: first and second perforated image portions in Example 1,
Mg21, Mg22, Mg23 ... the first, second and third perforated image portions in Example 2,
Mn: Print elongation adjustment hole,
Mn11, Mn12 ... first and second printing elongation adjusting holes in Example 1,
Mg21, Mg22, Mg23 ... the first, second and third printing elongation adjusting holes in Example 2,
α ... perforation rate, α11, α12 ... first and second perforation rates in Example 1,
α21, α22, α23... First, second and third perforation rates in Example 2, P.

Claims (1)

A stencil making unit for thermally piercing a perforated image portion on a stencil sheet to make a stencil sheet for one plate;
A paper feed unit for feeding paper one by one;
The stencil sheet for one plate made by the plate making unit is wound around an outer peripheral surface of a rotatable plate cylinder, and the ink oozed from the outer peripheral surface of the plate cylinder is sent from the paper feeding unit. A printing unit that prints an image corresponding to a perforated image portion of the stencil sheet for one plate on paper;
In a stencil printing apparatus comprising at least a control unit for controlling the entire apparatus,
The control unit divides the stencil sheet into at least two or more divided areas by a dividing line set along the rotation direction of the plate cylinder, and print elongation adjusting holes are formed in a portion where the ink does not bleed on the stencil sheet. The stencil printing apparatus is characterized in that thermal perforation is performed so that the perforation ratios calculated in each divided region are equal.

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