JP2009056654A - Stencil printing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stencil printing device for actualizing optimum image printing quality while suppressing printing wrinkles (a white-streak image failure) or the deviation of a master due to the flotation of a printmaking master, even when a printed medium to be used in the stencil printing device using active energy ray hardening ink is non-coated paper or coated paper such as high quality paper. <P>SOLUTION: A tapered hole is formed where a thickness Fh of a film 12-1 is 2.5-5 μm, the application amount (deposition amount or basis weight) of a porous resin film 12-2 is 1.0-1.9 g/m<SP>2</SP>, and a hole area Sk of the film 12-1 on the K-face of a melted hole portion 28 is 1/2 or smaller of a melted spread area Sf on the surface of the film 12-1 of the F-face. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a stencil printing apparatus provided with a plate making apparatus.

  As a simple printing method, a digital thermal stencil printing apparatus (hereinafter referred to as “stencil printing apparatus”) equipped with a digital thermal stencil making apparatus is known. In the plate making apparatus, a thermoplastic head (hereinafter simply referred to as “film”) is composed of a thermal head and a platen roller having a plurality of heating elements also called heating elements and heating resistors arranged in the main scanning direction. The image signal is obtained by relatively moving the master through rotation of the platen roller in the sub-scanning direction orthogonal to the main scanning direction while pressing a heat-sensitive stencil master (hereinafter referred to simply as “master”) having By heating each heat generating element of the corresponding thermal head, a dot-shaped perforated / plate making image (perforated pattern) is formed on the master.

In a general stencil printing machine, a master made by punching and making a plate-making image as described above is wound around the outer periphery of the plate cylinder, and then the plate cylinder is rotated to synchronize with the rotational movement of the plate cylinder. The printing paper (hereinafter, also simply referred to as “paper”), which is a printing medium, is conveyed between the plate cylinder and a pressing member such as a press roller or an impression cylinder at a predetermined timing. The printed master is pressed against the master on the cylinder, and the ink supplied into the cylinder is oozed out of the opening of the plate cylinder, the mesh screen and the perforated part of the master, and transferred to and transferred to the paper. It has become.
The printed matter to which the plate-making image has been transferred is then discharged toward the paper discharge tray and is sequentially stacked on the paper discharge tray. The ink used in a general stencil printing apparatus is an emulsion ink (hereinafter also referred to as “emulsion ink”), and the ink does not immediately fix after transfer onto a sheet. The drying of printed matter usually relies on absorption of ink onto paper over time, that is, natural drying. In other words, when stencil printing is performed, if normal printing ink is used, since the ink is permeated and dried, settling or squeezing occurs, so it is generally difficult to obtain a good double-sided printed material and the surface is glossy. Since art paper and coated paper having no color are not easily dried, it is difficult to obtain a good single-sided printed matter even with single-sided printing.

  Therefore, using light (ultraviolet) curable ink which is active energy ray curable ink and light (ultraviolet) irradiation means which is active energy ray irradiating means, stencil printing on stencil and art paper and coated paper An apparatus has been proposed (see, for example, Patent Documents 1 and 2).

JP 2004-136672 A JP 2006-281658 A

  However, in general stencil printing machines, the use of active energy ray-curable ink and coated paper printing are not considered, and in the printing of a combination of active energy ray-curable ink and coated paper, a master plate that has been subjected to plate making is used. Through experiments and the like, it has been found that printing wrinkles and master misalignment that cause white streak-like image defects due to the floating of the image are generated.

Therefore, the present applicant has already proposed a new technique related to “special plate making” or “special plate making mode” in order to prevent the occurrence of printing wrinkles and master misalignment. In other words, “special plate making” means that the odd-numbered bits corresponding to the odd numbers of the heating elements arranged in the thermal head and the perforations formed on the master film by the even-numbered bits corresponding to the even-numbered heating elements. The perforations formed in the master film are formed adjacent to each other on the same row in the main scanning direction so as to be formed on different rows in the main scanning direction and by the heat generation driving of adjacent odd and even bits. This is a plate-making method that controls the individual heating elements of the thermal head. Because the drilling pattern formed in the master obtained by special plate making is similar to that of a turtle shell, special plate making is commonly called "turtle shell plate making".
However, even with the technology relating to the above-described new special plate making, it has not yet been possible to completely suppress printing wrinkles (white streak-like image defects) and master deviation due to the float of the plate-making master.

  It is also conceivable to use a fast-drying emulsion ink that can be easily fixed (cured) on paper including coated paper, instead of the active energy ray-curable ink. Fast-drying emulsion inks are those that are easily fixed (cured) on the paper by increasing the resin component of the conventional emulsion ink components. There is a problem that the ink is stuck to a mesh screen (ink diffusing member) made of, for example, polyester, and the ink is hardened to cause clogging. Without this mesh screen, the ink does not diffuse, so that a hole in the plate cylinder appears in the image. In addition, the mesh screen used for the plate cylinder of the stencil printing machine generally has # 300 to # 450 having 300 to 450 meshes per inch.

Therefore, the present invention has been made in view of the above circumstances, and the printing medium used in the stencil printing apparatus using active energy ray-curable ink is uncoated paper such as fine paper or coated paper. The first object of the present invention is to realize and provide a stencil printing apparatus which can suppress printing wrinkles (white streak-like image defects) due to floating of a master plate already made and master deviation and obtain an optimum print image quality. And
It is a second object of the present invention to provide and provide a stencil printing apparatus in which the perforations of the plate cylinder do not appear in the image even when screen-less when using the fast drying emulsion ink.

In order to solve the above-described problems and achieve the above object, the present invention is characterized in that the invention according to each claim adopts the following configuration.
According to the first aspect of the present invention, a thermal head having a large number of heating elements arranged in the main scanning direction is directly provided on the thermoplastic resin film side of a master having at least a thermoplastic resin film and a porous resin film. The thermoplastic resin film is melted and perforated by position-selective heat generation driving of each of the heating elements according to an image signal while moving the master relatively in the sub-scanning direction orthogonal to the main scanning direction. A perforation pattern corresponding to the image signal is obtained, and a pre-printed master on which the perforation pattern is formed is wound around a plate cylinder provided on the outer periphery of the printing drum, and ink is supplied from the inner peripheral side of the plate cylinder. In the stencil printing apparatus for forming an ink image corresponding to the image signal on the printing medium with the ink oozed through the perforation pattern, the thickness of the thermoplastic resin film 2.5 to 5 μm, and the perforated area of the thermoplastic resin film on the surface facing the porous resin film is 1/2 or less of the melt spread area on the surface of the thermoplastic resin film facing the thermal head It has the 1st control means which controls the energy for perforation supplied to each above-mentioned heating element of the above-mentioned thermal head.

According to a second aspect of the present invention, in the stencil printing apparatus according to the first aspect, the coating amount of the porous resin film is 1.0 to 1.9 g / m ² .

  According to a third aspect of the present invention, in the stencil printing apparatus according to the first or second aspect, the ink is an active energy ray curable ink.

  According to a fourth aspect of the present invention, in the stencil printing apparatus according to any one of the first to third aspects, the odd-numbered bit corresponding to the odd number of each of the heating elements and the even-numbered heat generation corresponding to the even-numbered of each of the heating elements. The thermoplastic resin is formed such that perforations formed in the thermoplastic resin film by driving are respectively formed on different rows in the main scanning direction, and by heat generation driving of the adjacent odd and even bits. A second control means for controlling the thermal head is provided so that the perforations formed in the film are not adjacent to each other in the same row in the main scanning direction.

  According to a fifth aspect of the present invention, in the stencil printing apparatus according to any one of the first to fourth aspects, a plate making mode for executing a plate making operation corresponding to coated paper and uncoated paper as the printing medium is provided. Coated paper / non-coated paper separate plate making mode selection setting means that can be selectively set is provided.

  The invention according to claim 6 is the stencil printing apparatus according to claim 1 or 2, wherein the ink is a fast-drying emulsion ink.

  The invention according to claim 7 is the stencil printing apparatus according to claim 6, wherein the ink diffusing member is removed from the plate cylinder.

According to the present invention, a novel stencil printing apparatus can be realized and provided by solving the above-mentioned conventional problems. The effects for each claim are as follows.
According to invention of Claim 1, when the thickness of a thermoplastic resin film is 2.5-5 micrometers, the bending rigidity of a thermoplastic resin film rises and the thermoplastic resin of the surface which faces the porous resin film The perforated area of the film tends to be 1/2 or less of the melt spread area on the surface of the thermoplastic resin film facing the thermal head. In this way, the first control means supplies each heating element of the thermal head so that the area ratio between the perforated area and the melt spread area is 1/2 (the perforated cross section is tapered) or less. By controlling the perforating energy, the adhesive strength of the master between the thermoplastic resin film and the porous resin film can be increased. As a result, the bending strength also increases. It is possible to suppress printing wrinkles (white streak-like image defects) and master deviation due to sticking / floating on the print medium, and to obtain an optimum print image quality. Furthermore, by making the above area ratio 1/2 (for example, taper perforation in which the perforation cross section is tapered), the ink can be easily transferred to the printing medium and spread easily. Get better.

According to invention of Claim 2, when the application amount (adhesion amount, basic weight) of a porous resin film is 1.0-1.9 g / m < ² >, a porous resin film becomes difficult to tear, In addition, the ink passage resistance can be reduced. As a result, printing wrinkles (white streak-like image defects) and master deviation due to sticking and floating between the pre-printed master and the printing medium such as coated paper can be avoided. It is possible to obtain the optimum print image quality by suppressing.

  According to the third aspect of the invention, since the ink is an active energy ray curable ink, the ink image can be completely fixed.

  According to the fourth aspect of the present invention, the second control means forms on the thermoplastic resin film by heat generation driving of odd bits corresponding to the odd number of each heating element of the thermal head and even bits corresponding to the even number of each heating element. Perforations formed in the thermoplastic resin film by the heat generation drive of adjacent odd bits and even bits so that the perforations to be formed are respectively formed on different rows in the main scanning direction. Since the thermal heads are controlled so that they are not next to each other in a row, the bending strength of the master increases, and as a result, printing wrinkles (white It is possible to obtain an optimum print image quality by suppressing a streak-like image defect) and a master shift. When the plate making by the second control means is carried out, the distance between the perforated dots is increased and the image density is lowered. However, in combination with the invention according to claim 1, the solid filling of the ink image is also improved. , Can exert a more remarkable effect.

  According to the fifth aspect of the present invention, the plate making mode for performing the plate making operation corresponding to the coated paper and the non-coated paper as the printing medium is selectively set by the coated paper / uncoated paper separate plate making mode selection setting means. Therefore, the plate making mode can be changed according to the conditions of the printing medium.

  According to the invention described in claim 6, in addition to the effects of the invention described in claim 1 or 2, it is possible to fix the ink image when the ink is a fast-drying emulsion ink.

  According to the seventh aspect of the invention, the cost can be reduced by removing the ink diffusing member from the plate cylinder.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention including the best mode for carrying out the present invention and examples will be described below with reference to the drawings. Constituent elements such as members and components having the same function and shape throughout the embodiment and the modified examples are given the same reference numerals and will not be described after being described once. In order to simplify the drawings and the description, even components that are to be represented in the drawings may be omitted as appropriate without being specifically described in the drawings. When a constituent element such as a published patent publication is cited and explained as it is, the reference numeral is attached with parentheses to distinguish it from that of the embodiment.

FIG. 1 schematically shows the overall configuration of the digital thermal stencil printing apparatus according to the first embodiment of the present invention, and FIG. 2 shows the overall configuration of the main body of the digital thermal stencil printing apparatus in FIG. Show.
In this embodiment, since the active energy ray curable ink can be used, the active energy ray curable fixing device 201 for curing the active energy ray curable ink is the discharge side of the stencil printing apparatus of FIG. It is attached to. As an example of the active energy ray curable ink, an ultraviolet curable ink is used. As an example of the active energy ray curable fixing device, an ultraviolet curable fixing device is used.

In FIG. 1, reference numeral 200 denotes a stencil printing apparatus main body shown in detail in FIG. 2, and a paper feeding unit 202 is provided on the right side of the stencil printing apparatus main body 200. As described above, the active energy ray curing and fixing device 201 is provided on the paper discharge side of the stencil printing apparatus main body 200. In this active energy ray curable fixing device 201, an active energy ray lamp, a motor for conveying paper, a belt, an adsorption fan, and the like are incorporated. The active energy ray curable fixing apparatus 201 fixes the active energy ray curable ink onto the paper, and the printed / fixed paper is discharged to the paper discharge table 204 by belt / adsorption conveyance. In FIG. 1, a paper feeding unit 202 is substantially the same as a paper feeding unit 110 (shown in parentheses in FIG. 1) disposed on the paper feeding side of the stencil printing apparatus main body 200 shown in FIG. In other words, the sheet feeding table 203 of the sheet feeding unit 202 and the sheet feeding table 51 (shown in parentheses in FIG. 1) of the sheet feeding unit 110 are the same. Similarly, the paper discharge table 204 and the paper discharge table 52 (shown in parentheses in FIG. 1) indicate the same thing.
The internal configuration of the active energy ray curable fixing device 201 is the same as the UV irradiation device (2) as the ultraviolet irradiation device shown in FIG. 1 of JP-A-2006-281658 proposed by the present applicant, for example. In relation to this, on the stencil printing apparatus main body 200 side shown in FIG. 2, the stencil printing control apparatus (55) described in FIG. 4 of Japanese Patent Laid-Open No. 2006-281658 related to Patent Document 2 is the same. A configuration is provided.

  First, the overall configuration of the stencil printing apparatus main body 200 will be described with reference to FIG. In FIG. 2, reference numeral 50 denotes an apparatus main body forming a framework on the stencil printing apparatus main body 200 side. As shown in the figure, the portion indicated by 80 in the upper part of the apparatus main body 50 is a document reading portion as a document reading device, and the portion indicated by 1 below is a plate making portion as a digital thermal stencil type plate making device. A portion indicated by 20 on the left side of the plate making unit 1 is a printing drum unit as a printing drum device in which a printing drum 21 having a porous cylindrical plate cylinder on the outer peripheral portion is disposed, and a portion 120 below the printing drum 21. A portion shown is a printing pressure unit as a printing pressure device, a portion indicated by 70 on the left side of the printing drum 21 is a plate discharging portion as a plate discharging device, and a portion indicated by 110 below the plate making unit 1 is a paper feeding device as a paper feeding device. The part indicated by the reference numeral 130 on the left side of the printing pressure device 120 and below the plate discharging device 70 indicates a paper discharge unit as a paper discharge device. As described above, in the stencil printing apparatus shown in FIG. 2, the plate making unit 1 is integrally provided in the apparatus main body 50.

  The document reading unit 80 has a function of reading an image of the surface of the document 60 transferred from a document placing table (not shown), and the plate making unit 1 has a function of making a master 12 wound in a roll shape and feeding and feeding it. The printing drum unit 20 has a function of winding the master-made master 12 around its outer peripheral surface and supplying ink to the master-made master 12 on the printing drum 21. The plate discharging unit 70 peels off the used master 12 from the outer peripheral surface of the printing drum 21 and presses a sheet 62 as a printing medium against the sheet 21 to form a print image on the sheet 62. The paper feeding unit 110 has a function of discharging and discharging the plate into the paper 74, and the paper feeding unit 110 has a function of feeding the paper 62 stacked on the paper feeding table 51 between the printing drum unit 20 and the printing pressure unit 120. 130 is a printing drum The function of discharging to the discharge tray 52 parts 20 and the paper 62 printed by indicia pressure part 120 has, respectively.

With reference to FIGS. 2 to 4, the basic operation of the stencil printing apparatus when the normal plate-making mode is set as in the prior art will be described.
First, a user places and sets a document 60 having an image to be printed on a document placing table (not shown) disposed at the top of the document reading unit 80, and makes a plate making start key 91 on the operation panel 90 shown in FIG. Press. In response to pressing of the plate making start key 91, a plate making start signal is generated, and this is used as a trigger to first execute the plate discharging process. That is, in this state, the used master 12 used in the previous printing remains attached to the outer peripheral surface of the printing drum 21. The printing drum 21 is connected to printing drum driving means (not shown, for example, a main motor) via a driving mechanism (not shown), and is rotated by the printing drum driving means.

  The printing drum 21 rotates in the direction opposite to the arrow direction A in the figure, and the rear end portion of the used master 12 mounted on the outer peripheral surface of the printing drum 21 approaches the plate-removing roller pair 71a, 71b of the plate-discharging unit 70. The roller pair 71a, 71b rotates while scooping up the rear end of the used master 12 with one of the plate release roller 71b, and a plate discharge roller pair 73a disposed to the left of the plate release roller pair 71a, 71b. , 73b and a pair of discharge plate conveying belts 72a and 72b spanned between the pair of discharge plate peeling rollers 71a and 71b, the used master 12 is gradually peeled off from the outer peripheral surface of the printing drum 21 by the discharge plate peeling and conveying device. Then, the sheet is discharged into the discharge plate box 74 while being conveyed in the arrow direction Y1, and the so-called discharge process is completed. At this time, the printing drum 21 continues to rotate counterclockwise. The discharged used master 12 is then compressed inside the discharge plate box 74 by the compression plate 75.

In parallel with the plate removal process, the document reading unit 80 operates to read the document. That is, the document 60 placed on the document placing table is moved in the directions indicated by the arrows Y2 to Y3 (hereinafter, “ Document reading direction Y2 ") and being subjected to exposure reading. At this time, when there are a large number of documents 60, only the lowermost document is conveyed by the action of the separating blade 84.
The upper rear document transport roller 83a is rotationally driven by a document transport motor (not shown) made of, for example, a stepping motor. The upper front document transport roller 82a is rotationally driven by the document transport motor via a timing belt (not shown) spanned between the upper transport roller 83a and the transport roller 82a, and each roller 82b, 83b. Each follower rotation. At this time, in response to a command from the sub-scanning direction feed speed control means included in the other control means 7 shown in FIG. 4, the document transport motor sets the sub-scan feed pitch of the document 60 in the sub-scanning direction resolution (dot / dot). It is controlled to change to a predetermined sub-scan feed pitch corresponding to (inch). Further, the present invention is not limited to this, and it may be read at a predetermined sub-scan feed pitch, stored once in a document memory as image storage means, and processed.

When reading the image of the original 60, the reflected light from the surface of the original 60 illuminated by the fluorescent lamp 86 while being transported on the contact glass 85 is reflected by the mirror 87 and passes through the lens 88, and then the CCD (photocoupler such as a charge coupled device) This is performed by being incident on an image sensor 89 formed of a conversion element. The document 60 from which the image has been read is discharged onto the document tray 80A.
The document reading unit 80 has a structure having various functions for color separation necessary for multicolor overprint printing, for example, a filter unit capable of switching a plurality of color filters described in Japanese Patent Application Laid-Open No. 64-18682. Those having a similar function and configuration are disposed on the optical path between the mirror 87 and the lens 88.

2 and 4, the optical information (image data) of the document 60 is photoelectrically converted by the image sensor 89, and the analog electrical signal is input to an analog / digital (A / D) converter and converted into a digital image signal. Is done. This digital image signal is subjected to image processing for stencil printing by the image processing unit 4 in the control unit 2 shown in FIG. 4, and the digital image signals relating to the binary black pixels and white pixels thus subjected to image processing are It is input to the thermal head drive control unit 5 shown in FIG. The thermal head drive control unit 5 controls the individual heating elements 9 of the thermal head 10 shown in FIGS. 2 and 4 mainly through a thermal head drive circuit (not shown). The microcomputer shown in FIG. A control operation is performed in response to a command from the peripheral circuit 3.
Hereinafter, description will be made on the assumption that conventionally well-known normal plate making is performed. “Regular plate making” means that the perforations formed in the thermoplastic resin film of the master 12 by the heat generation driving of the individual heating elements 9 of the thermal head 10 according to the digital image signal are the same in the main scanning direction of the thermal head 10. It means a well-known plate making method formed on one line. In the thermal head drive control unit 5, first control means for controlling the individual heating elements 9 of the thermal head 10 so as to execute the above-described normal plate making is provided.

  The optical information (image data) input to the A / D conversion unit is not limited to that read by the CCD, and may be information from a contact image sensor (CIS) or the like, for example. The digital image data input to the thermal head drive control unit 5 in the control unit 2 may be a digital image signal transmitted from a computer such as a personal computer.

  The digital image signal input to the thermal head drive control unit 5 in the control unit 2 is used for various known controls, that is, thermal history control by the thermal history control means provided in the control unit 2, and common drop by the common drop correction control means. A correction control and the like are appropriately performed, and various other controls and the like are appropriately performed by the control means 7 so that a digital image data signal (hereinafter simply referred to as “data signal” or “DATA signal”) is used as a thermal head driving signal. Abbreviated), clock signal (hereinafter also abbreviated as “CLK signal”), latch signal (hereinafter abbreviated as “LATCH signal”), energization signal (hereinafter also abbreviated as “strobe signal” or “STB signal”) Are generated and transmitted to the thermal head 10 via a thermal head drive circuit (not shown).

On the other hand, in parallel with such document scanning and image reading operations, plate making and plate feeding processes are performed based on digital signalized image information (digital image signal). That is, when the master-making motor 11 formed of a stepping motor, for example, is rotationally driven by the plate-making start signal as a trigger, the master 12 is set so that it can be fed out via a master support member (not shown). The master 12 is pulled out from the master roll 12A formed by being wound around the roll. At this time, the master 12 is rotated by a constant speed of the platen roller 14 and the tension roller pairs 15a and 15b as master conveying means pressed against the thermal head 10 via the master 12, and the sub-scan indicated by the arrow Y in the figure. It is transported downstream in the direction Y (hereinafter also referred to as “master transport direction Y”).
At this time, in response to a command from the sub-scanning direction feed speed control means in the other control means 7 shown in FIG. 4, the master feed motor 11 sets the sub-scan feed pitch of the master 12 to a predetermined value corresponding to the resolution in the sub-scan direction Y. The sub-scan feed pitch is controlled to be changed.
A large number of minute heating elements 9 arranged in a line in the main scanning direction of the thermal head 10 are sent from the thermal head drive control unit 5 in the control unit 2 to the conveyed master 12. Each of the film portions of the master 12 in contact with the heat-generating element 9 that generates heat selectively in accordance with the digital image data signal is heated, melted and punched. In this way, image information is written in the master 12 as a drilling pattern by position-selective melt drilling of the master 12 according to the image information.

The platen roller 14 is connected to the master feed motor 11 via a rotation transmission member (not shown) such as a timing belt and a gear, and is rotated by the master feed motor 11. The master feed motor 11 is composed of a stepping motor, for example. The rotational driving force of the master feed motor 11 is supplied to a pair of upper and lower reversing rollers 17a, 17b via a tension transmission pair 15a, 15b and an electromagnetic clutch (not shown) via a rotation transmission member (not shown) such as a gear. To be communicated to.
There is also a device in which a stepping motor other than the master feed motor 11 that rotates the driving rollers of the reverse rollers 17a and 17b is provided instead of the electromagnetic clutch.

The leading end of the master 12 having image information written therein is sent out toward the outer periphery of the printing drum 21 by the pair of reverse rollers 17a and 17b, and the traveling direction is changed downward by the plate feeding guide plate 18. Then, it hangs down toward the expanded master clamper 22 of the printing drum 21 in the plate feeding position state indicated by a two-dot chain line in FIG. At this time, the used master 12 has already been removed from the printing drum 21 by the plate discharging process.
When the leading end of the master 12 that has been subjected to plate making is clamped and held by the master clamper 22 at a fixed timing by the operation of an opening / closing device (not shown) disposed on the apparatus main body 50 side to open and close the master clamper 22, the printing drum 21 Is gradually wound around the outer peripheral surface of the master 12 while rotating in the arrow A direction (clockwise direction). After the plate making is completed, the rear end portion of the master 12 that has been made is cut into a certain length by the cutter 13, and the master 12 that has been made one plate is completely wound around the outer peripheral surface of the printing drum 21. The plate making and feeding processes are completed.

After that, the rotation of the platen roller 14, the tension roller pair 15a, 15b, and the reverse roller pair 17a, 17b causes the upstream end of the cut master 12 to be transported toward the nip portion of the reverse roller pair 17a, 17b. The When the leading edge of the master 12 thus transported is detected by a master leading edge detection sensor (not shown) and it is determined that the leading edge of the master 12 has occupied the initial position, the platen roller 14, the tension roller pairs 15a and 15b, and the reverse roller pair 17a, The rotation of 17b is stopped, and a plate-making standby state is prepared for the next plate-making. The initial position of the master 12 is set in advance, for example, at a position that protrudes slightly forward from the position sandwiched between the nip portions of the pair of reverse rollers 17a and 17b.
The platen roller 14, the tension roller pairs 15a and 15b, the reverse roller pairs 17a and 17b, and the master feed motor 11 constitute a means for conveying the master 12. These are collectively referred to as a master conveying means 19 in FIG. And

  Next, the printing process is started. First, the uppermost one of the sheets 62 stacked on the sheet feeding table 51 is pulled out by the sheet feeding roller 111 and further separated into one sheet by the cooperative action of the separation roller pairs 112a and 112b. The printing unit is fed in the direction of the arrow Y4 (hereinafter referred to as “paper transport direction Y4”) toward the roller pair 113a and 113b, and further at a predetermined timing synchronized with the rotation of the printing drum 21 by the registration roller pair 113a and 113b. The sheet is fed between the printing drum 21 and the press roller 23 at 120. The press roller 23 can be brought into contact with and separated from the outer peripheral surface of the printing drum 21 by a known press roller displacing means (not shown). The press roller 23 is supplied to the printing drum 21 on which the master 12 having been made on the outer peripheral surface is wound. It functions as a pressing unit that presses the fed paper 62 and forms a print image on the paper 62. When the fed paper 62 is inserted between the printing drum 21 and the press roller 23, the press roller 23 that has been separated below the outer peripheral surface of the printing drum 21 is swung and raised. As a result, it is pressed against the master 12 that has been pre-rolled around the outer peripheral surface of the printing drum 21. In this way, due to the adhesive force due to the viscosity of the ink that has oozed out from the porous portion of the printing drum 21, the master 12 that has been subjected to plate making comes into close contact with the outer peripheral surface of the printing drum 21, and at the same Ooze out and the oozed ink is transferred to the surface of the paper 62 to form a printed image.

At this time, on the inner peripheral side of the printing drum 21, the ink is supplied from the ink supply pipe 24 also serving as the support shaft 24 to the ink reservoir 27 formed between the ink roller 25 and the doctor roller 26, and the printing drum 21 rotates. Ink is supplied to the inner peripheral side of the printing drum 21 by the ink roller 25 that is in rolling contact with the inner peripheral surface while rotating in the same direction as that of the printing drum 21 in synchronization with the rotational speed of the printing drum 21.
The ink supply tube 24, the ink roller 25, and the doctor roller 26 constitute an ink supply unit that supplies ink to the master 12 that has been made on the printing drum 21. The pressing means is not limited to the press roller 23, and an impression cylinder having a diameter substantially the same as the diameter of the printing drum (plate cylinder) 21 is also used. Of course, the present invention is applied to such an impression cylinder type stencil printing apparatus. The

  For example, W / O type emulsion ink is preferably used as the ink used when printing on uncoated paper such as high-quality paper when the conventional normal plate-making mode is set. Hereinafter, in this embodiment, in order to simplify explanation, it demonstrates as what uses the ultraviolet curable ink as an active energy ray curable ink. Hereinafter, the simple ink means an active energy ray curable ink (ultraviolet curable ink).

The paper 62 on which the print image is formed in the printing pressure unit 120 is peeled off from the print drum 21 by the paper discharge peeling claw 114 in the paper discharge unit 130 and sucked by the suction fan 118 while being sucked by the suction paper discharge inlet roller 115 and the suction. It is attracted to the porous conveyor belt 117 that is stretched around the sheet discharge outlet roller 116, and is conveyed toward the sheet discharge tray 52 as indicated by the arrow Y5 by the rotation of the conveyor belt 117 in the counterclockwise direction. The sheets are sequentially discharged and loaded on the table 52. In this way, so-called plate printing is completed. The printing speed at the time of plate printing is set to a low speed such as 16 to 20 sheets / min (min).
After the plate printing is completed, the press roller 23 is separated from the printing drum 21, and the printing drum 21 returns to the initial position (home position) at which the master clamper 22 is substantially above in FIG.

  Next, a desired print speed value is set by pressing a print speed setting key (not shown) arranged on the operation panel 90 shown in FIG. When the print start key 92 is pressed and the printing start key 92 is pressed, the paper feeding, printing, and paper ejection steps are repeated for the set number of prints at the set printing speed in the same process as the stencil printing. This completes the entire process.

Hereinafter, the details of the plate making unit 1, the operation panel 90, the printing drum unit 20, and the like will be described with respect to the configuration of the master 12 unique to the present embodiment and the main configuration related thereto.
As described above, the thermal head 10 is a personal computer (not shown) for receiving digital image signals from the image sensor 89, the A / D converter (not shown), the image processor 4 or the like, or from a personal computer (not shown). Thermal head driving signals including digital image data signals that are processed and transmitted by the thermal head drive control unit 5 of the control unit 2 via the image processing unit via the controller, interface device, data development unit, etc. On the basis of the above, a number of heating elements 9 are heated in a position-selective manner, so that the master 12 has a function as a plate-making means for selectively hot-melting and perforating the master 12. The thermal head 10 can be brought into and out of contact with the platen roller 14 via a master 12 by a well-known contacting / separating means (not shown).
The plate making unit 1 constitutes a plate making unit that can be attached to and detached from the apparatus main body 50 via a known attaching / detaching means.

In this stencil printing apparatus, as the thermal head 10, a thin-film thermal head that is generally called a planar thermal head is used. However, the thermal head 10 is not limited to this and is arranged in the main scanning direction. As long as it has a plurality of (many) heating elements, all known types and types are included. That is, the thermal head 10 may be a planar thermal head, an end face thermal head, a real edge thermal head, or a corner edge thermal head.
Further, as the heating element 9 of the thermal head 10, a rectangular shape is usually used in a plan view, but a heat concentration type may be used.

As described above, the plate making unit 1 brings the portions of the many heating elements 9 arranged in the main scanning direction of the thermal head 10 into contact with the film of the master 12, and sets the master 12 in the sub-scanning direction orthogonal to the main scanning direction. The film of the master 12 is melted and punched by position-selective heating of the individual heating elements 9 according to the image data (image signal) and moved in the sub-scan feed pitch. This is an apparatus for forming a plate-making image (perforation pattern) on the master 12.
In the plate making unit 1 of the present embodiment, the resolution in the sub-scanning direction Y when the master 12 is relatively moved in the sub-scanning direction Y is set in advance to be the same as the resolution of the thermal head 10. The feed operation for transporting the master 12 in the sub-scanning direction Y is not limited to the intermittent movement at a predetermined feed pitch as in the above example, and the master 12 may be sent continuously. Further, not only the document reading unit 80, but also a scanner moving method in which the document 60 is placed and fixed on the contact glass, and the scanning optical system including a fluorescent lamp and a mirror is moved by a driving motor to read the document. It may be adopted. In this case, the drive motor may be controlled so that the moving speed of the scanning optical system is changed to a predetermined feed pitch corresponding to the resolution in the sub-scanning direction Y.

  Adjustment / change of applied energy (perforation energy) is applied to each heating element 9 of the thermal head 10 according to an image signal or applied to the heating element 9 as described in Japanese Patent No. 2756219. However, it is generally performed by changing the energization pulse width supplied to each heating element 9 of the thermal head 10 via the thermal head driving circuit. Therefore, this will be described.

The operation panel 90 is disposed on one side of the upper part of the document reading unit 80. As shown in FIG. 3, the operation panel 90 includes a plate making start key 91, a printing start key 92, a numeric keypad 93, a trial printing key 94, an enter key 95, a mode clear key 96, a touch panel 98, a display device 99, and the like. Has been. Further, as shown in FIG. 4, the operation panel 90 is also provided with functions that function as notifying means and coated paper / non-coated paper setting means. These will be described later.
The plate making start key 91 functions as an operation starting means for starting a series of steps (operations) from reading of an image of a document to plate discharge, plate making, plate feeding, paper feeding, plate printing, and paper discharge steps. The numeric keypad 93 has a function for inputting and setting the number of prints and the like, the print start key 92 has a function for starting the printing operation for the number of prints inputted and set with the numeric keys 93, and the trial printing key 94 has Each has a function of starting a test printing operation. The enter key 95 has a function for confirming / setting values and the like at various settings, and the mode clear key 96 has a function for erasing / clearing various mode setting states. Is done.

The touch panel 98 is driven by an LCD (Liquid Crystal Display) driving circuit including a touch panel driving circuit (not shown), and various modes and various selection setting means (coated paper / non-coated paper setting described above) displayed on the screen by a known touch panel method. Means) can be selected and set in black and white reversed display.
The display means or notification means comprising an LCD screen disposed on the touch panel 98 displays or notifies when the ink used does not match the coated paper or non-coated paper. Specifically, the touch panel A display / notification such as “This combination cannot be printed” is displayed in 98.
The coated paper / non-coated paper setting means is a coated paper / non-coated paper separate plate-making mode selection setting means capable of selectively setting a plate-making mode for executing a plate-making operation corresponding to each of coated paper and non-coated paper. Specifically, it includes a coated paper setting key 131 and an uncoated paper setting key 132 provided on the touch panel 98.

  The notification means is not limited to the one displayed on the touch panel 98, but uses, for example, simple LCD display, LED display, voice notification, sounding warning sound by the buzzer 97 disposed on the operation panel 90 or the like, or 7 segments of LED. Code notation may be used, or a combination thereof may be used. The coated paper / non-coated paper setting means is not limited to that provided on the touch panel 98. For example, a dedicated key may be provided or set with a plurality of selection setting keys while being hierarchically displayed on the LCD.

With reference to FIG. 4, the control configuration for controlling mainly the plate making unit 1 and the operation panel 90 of the stencil printing apparatus will be described. As shown in the figure, the microcomputer peripheral circuit 3 in the control unit 2 includes a microcomputer having a CPU, ROM, RAM, internal timer, I / O port, A / D converter, various counters, and the like. Configured.
The CPU of the microcomputer peripheral circuit 3 has calculation and control functions, and comprehensively controls an image processing unit 4, a thermal head drive control unit 5 and other control means 7 which will be described later. The ROM of the microcomputer peripheral circuit 3 stores in advance an operation program and related data for performing the above functions of the microcomputer peripheral circuit 3. The RAM of the microcomputer peripheral circuit 3 temporarily stores data from various sensors and calculation results of the microcomputer peripheral circuit 3.

  With reference to FIG. 5 to FIG. 9, a specific configuration of the master 12 used in the stencil printing apparatus of the present embodiment and a melt perforation portion of the master 12 that is melt perforated by the thermal head 10 will be described in detail. 6 illustrates the porous resin film 12-2 and the porous fiber film 12-3 of the master 12, and FIGS. 7A, 7B, 8A, and 8B illustrate the porous fibers. The film 12-3 and the paper 62 such as coated paper are not shown, and the films 12-1, the porous fiber film 12-3 and the paper 62 such as coated paper are not shown in FIGS. 9A and 9B. is doing.

The master 12 used in the stencil printing apparatus of this embodiment is a master having at least a thermoplastic resin film and a porous resin film as described in JP-A-10-147075, that is, specifically shown in FIG. As shown specifically, a porous resin film 12-2 made of a resin is provided on one surface of the thermoplastic resin film 12-1, and a porous fiber film 12-3 made of a fibrous material (hereinafter, In other words, the master 12 formed by laminating “porous support 12-3” is used. As the thermoplastic resin film 12-1, for example, a polyethylene terephthalate (PET) type film is used. However, the thermoplastic resin film 12-1 may be made of other materials described in JP-A-10-147075. The material of the porous resin film 12-2 and the porous support 12-3 is the same as that described in JP-A-10-147075.
The master 12 used in the stencil printing apparatus according to the present embodiment is compared with the master for thermal stencil printing described in JP-A-10-147075, and the thickness and porosity of the thermoplastic resin film are described later. The main difference is that the application amount (adhesion amount, basis weight) of the resin film and the cross-sectional shape / area ratio of the melt perforated part are set within a certain range, and the basic configuration of the other masters is the same. . Therefore, the master 12 used in the stencil printing apparatus according to the present embodiment has the same effect as that described in the column of the effect of the invention of paragraph “0114” of the above-mentioned Japanese Patent Application Laid-Open No. 10-147075. The tensile strength is strong, the master can be prevented from stretching during printing, the perforation by the thermal head is not hindered, and the ink is evenly dispersed with the porous resin film, so that there is no uneven printing due to fiber overlap). Of course, it is a thing.

FIG. 5 shows a schematic perforated state of the master 12 in the present embodiment (the present invention) in a central section. In the figure, the meaning of each symbol is summarized as follows.
Fh: means the thickness of the thermoplastic resin film 12-1 (hereinafter also referred to as “film 12-1”).
Sk: The perforated area of the film 12-1 on the surface facing the porous resin film 12-2, and hereinafter also referred to as the perforated area of the film 12-1 on the K surface.
Sf: Means the melt spread area of the surface of the film 12-1 facing the heating element 9 of the thermal head 10, and hereinafter also referred to as the melt spread area of the surface of the film 12-1 of the F plane.
Sp: means the area ratio of the perforated area Sk of the K-side film 12-1 to the melt spread area Sf of the F-side film 12-1, and Sp = Sk / Sf <0.5.

As a feature of this embodiment, first, the thickness Fh of the film 12-1 shown in FIG. 5 is 2.5 to 5 μm, and secondly, the porous resin film 12-2 shown in FIG. The amount (attachment amount, basis weight) is 1.0 to 1.9 g / m ² , and third, the perforated area Sk of the K-side film 12-1 in the melt perforated part 28 shown in FIG. That is, it is 1/2 or less of the melt spread area Sf on the surface of the film 12-1 (hereinafter also referred to as “taper drilling” for short).
For reference, when the characteristics of the master 12 used in the past are shown, the thickness Fh of the film 12-1 is 1.2 to 2.0 μm, and the coating amount of the porous resin film 12-2 is 1.6 to 1.9 g / m ² .

  Depending on the thickness Fh, material, etc. of the film 12-1, the energization pulse width and the like for energizing and supplying the individual heating elements 9 of the thermal head 10 are adjusted and controlled, and the area ratio Sp is 1/2 (0.5) Try to be as follows. In this sense, the microcomputer peripheral circuit 3 and the thermal head drive control unit 5 shown in FIG. 4 are closely related to the use of the master 12 unique to the present embodiment, and the porous resin film 12-2. The perforated area Sk of the thermoplastic resin film 12-1 on the facing surface is equal to or less than ½ of the melt spread area Sf on the surface of the thermoplastic resin film 12-1 on the surface facing the heating element 9 of the thermal head 10. In addition, it functions as a first control means for controlling the energization pulse width (perforation energy) to be energized and supplied to the individual heating elements 9 of the thermal head 10.

First, in the present embodiment, the thickness of the thermoplastic resin film 12-1 is increased to increase the bending stiffness of the master 12, and at the same time, the area ratio Sp of the melt-pierced portion is ½ (0.5) or less. Make it easy to do.
Here, the relationship between the thickness Fh of the thermoplastic resin film 12-1 and the area ratio Sp will be described with reference to FIG. In FIG. 6, the thermal energy distribution of each heating element 9 of the thermal head 10 has the highest temperature at the center of each heating element 9, and is expressed as a normal distribution, for example. The initial stage of melting of the film 12-1 was σ1 thermal energy distribution, but when the film 12-1 was melted from the initial h1 to h2 in the thickness Fh, the corresponding thermal energy was consumed (stolen), Each heating element 9 of the thermal head 10 has a thermal energy distribution indicated by σ2. Thus, with the dissolution of the film 12-1, the thermal energy distribution of each heating element 9 of the thermal head 10 becomes smaller. Here, assuming that the melting temperature of the film 12-1 is t ° C., the inside of the line connecting the points where the intersection of the temperature line of the t ° C. and the thermal energy distribution is projected on the film 12-1 by a dotted line is the film 12-1. It becomes a part of the melt | dissolution perforation part 28.

Therefore, the thicker the thickness Fh (μm) of the film 12-1, the smaller the perforated area Sk of the surface facing the porous resin film 12-2. In other words, as described above, tapered perforation that makes the area ratio Sp of the melt perforated portion 28 0.5 or less can be easily formed by giving the film 12-1 a thickness.
In addition, by setting the area ratio Sp of the melt punched portion 28 to 0.5 or less (tapered punching), the thermoplastic resin film 12-1 and the porous resin can be formed even if punched by each heating element 9 of the thermal head 10. Since the contact area with the film 12-2 can be maintained, the adhesive force between the two does not decrease, and the master 12 that has been subjected to the plate making at the time of printing adheres to the paper 62 such as a coated paper and the thermoplastic resin film 12-1. And the porous resin film 12-2 are separated and separated from each other, and the thermoplastic resin film 12-1 is floated, and the master 12 that has been subjected to plate making can be prevented from being wrinkled. Further, the bending stiffness of the master 12 that has been made is also increased.

Further, as shown in FIG. 7 (a), by setting the area ratio Sp of the melt drilled portion 28 in the master 12 of the present embodiment (the present invention) to 0.5 or less (tapered drilling), the arrow 29 in the figure indicates As shown, the spread of the ink is increased, and the ink is easily transferred and transferred to a paper such as a coated paper, and spreads easily, so that the solid filling is also improved.
In particular, as described in the second embodiment to be described later, when the plate making conditions are set to a special plate making (tortoise shell making) described later, the distance between perforated dots increases and the image density also decreases. The effect is demonstrated.

  On the other hand, in the comparative example shown in FIG. 7B, even if the thickness of the film 12-1 is the same as that of the master 12 of the present embodiment (the present invention) shown in FIG. When the area ratio Sp of the melt perforated portion 28 is 0.6 or more and the cross section thereof is in a perforated state close to a straight, the ink spread is compared with that shown in FIG. As the ink becomes smaller and the ink is difficult to transfer and transfer to a paper such as a coated paper and difficult to spread, the solid filling becomes worse.

  Next, referring to Table 1 that summarizes the experimental results of perforating plate making on the master 12 using the thickness Fh of the film 12-1 as a parameter and performing stencil printing on the coated paper using the master 12 already made. I will explain. In Table 1, the thickness Fh of the film 12-1 is changed in the range of 1 to 2 μm, 2.5 to 5 μm, and 6 to 10 μm. The relationship between the area ratio Sp (= Sk / Sf), wrinkles and solid filling is summarized. In Table 1, symbol ◎ indicates an OK result indicating that the experimental evaluation result is good, symbol ○ indicates that the experimental evaluation result is in a practical range, and symbol X indicates that the experimental evaluation result is out of the practical range and cannot be used. The result indicates that the symbol Δ is an intermediate result between ○ and × (the same applies to Table 2 described later).

  From the experimental results summarized in Table 1, with respect to wrinkles, the film 12-1 is better to be thicker due to rigidity, and 2.5 μm or more is effective. However, in reality, if it is too thick (becomes 6 μm or more), the number of holes that do not penetrate increases and the perforation probability decreases, and even if the film 12-1 is thin (1-2 μm, the area ratio Sp = 0. Although it is possible to make a perforation of 5 or less, the solid filling is improved, but since the film 12-1 is thin, the rigidity is weak and the effect of suppressing wrinkles is not very much obtained. The range surrounded by a thick solid line in FIG. 1, that is, the condition that the thickness Fh of the film 12-1 is 2.5 to 5 μm and the area ratio Sp = 0.5 or less is a condition for obtaining a better effect. .

Furthermore, as shown to Fig.8 (a), the application quantity (adhesion amount, basic weight) of the porous resin film 12-2 in the master 12 of this embodiment (this invention) is small, 1.0-1.9g. / M ² reduces the ink passage resistance as indicated by the thin arrow 30 in the figure, and the stress on the master 12 of the present embodiment (the present invention) as shown in FIG. 9A. At the same time, since the coating amount of the porous resin film 12-2 is small as described above, it becomes difficult to tear as indicated by the arrow 31 in the figure, and printing wrinkles (white streak-like images) due to floating of the master 12 that has been subjected to plate making Defective) can be suppressed.

On the other hand, in the comparative example shown in FIG. 8B, even if the thickness of the film 12-1 is the same as that of the master 12 of the present embodiment (the present invention) shown in FIG. When the coating amount (adhesion amount, basis weight) of the porous resin film 12-2 is large, for example, 2.0 g / m ² or more, the ink passage resistance increases as shown by the thick arrow 30 in the figure. As shown in FIG. 9B as a comparative example, as the stress on the master 12 increases and the amount of the porous resin film 12-2 applied is large as described above, as indicated by the arrow 31 in FIG. It becomes easy to tear, and it becomes difficult to suppress printing wrinkles (white streak-like image defects) due to floating of the master 12 that has been subjected to plate making.

  Next, Table 2 summarizes the results of experiments on the effect on printing wrinkles and solid filling by changing the coating amount (adhesion amount, basis weight) of the porous resin film 12-2 to four stages. Will be described with reference to FIG.

表２において、多孔性樹脂膜１２−２の各塗布量とも、フィルム１２−１の厚みＦｈが２．５〜５μｍで、かつ、面積比Ｓｐ＝０．５以下の同一条件で行った実験結果の評価結果である。
表２にまとめた実験結果から、多孔性樹脂膜１２−２の塗布量については、〜０．９ｇ／ｍ^２では製造上困難であることから適当でなく、また上述した内容から、表２において太い実線で囲んだ多孔性樹脂膜１２−２の塗布量が、１．０〜１．９ｇ／ｍ^２の範囲で好ましく、特に１．０〜１．５ｇ／ｍ^２が製版済みのマスタ１２の浮きによる印刷シワ（白スジ状の画像不良）を抑制するとともにベタ埋りを良好とする点から最も好ましい範囲であることが判った。

In Table 2, the results of experiments conducted under the same conditions with the coating amount of the porous resin film 12-2 being the thickness Fh of the film 12-1 of 2.5 to 5 μm and the area ratio Sp = 0.5 or less. This is the evaluation result.
Experimental results are summarized in Table 2, the coating amount of the porous resin film 12-2, not suitable since it is 0.9 g / m ² in the manufacture difficult, also from what has been described above, in Table 2 thick coating amount of enclosed porous resin film 12-2 in a solid line, preferably in the range of 1.0~1.9g / ^{m 2,} in particular 1.0 to 1.5 g / ^{m 2} of stencil master 12 It was found that this is the most preferable range in terms of suppressing printing wrinkles (white streak-like image defects) due to floating and improving solid filling.

Next, the operation of this embodiment executed under the command of the CPU of the microcomputer peripheral circuit 3 of the control unit 2 shown in FIG. 4 will be briefly described. In this operation description, only the part related to the present invention will be described, and the other parts are well known and will be omitted.
First, when the plate making operation is executed, the coated paper setting key 131 or the uncoated paper setting key of the coated paper / non-coated paper setting means (coated paper / non-coated paper separate plate making mode selection means) described above with respect to the paper to be used. Touch 132 to set. In this embodiment, regardless of whether coated paper or non-coated paper is set, the plate making mode in which the melt perforated portion 28 of the master 12 is formed in the above-described unique tapered cross-sectional shape, that is, the melt perforated portion shown in FIG. A plate-making mode is automatically set so that the perforated area Sk of the K-side film 12-1 at 28 is equal to or less than ½ of the melt spread area Sf of the F-side film 12-1.
Next, after the plate making is completed with the contents of the plate making mode, a printing operation similar to that described with reference to FIG. 2 is executed, and then the printed paper is printed by the active energy ray curing and fixing device 201 shown in FIG. Is completely established.

  As described above, according to the present embodiment, it is needless to say that the effects described in the column of the effects of the invention and the advantages and effects described as appropriate are exhibited.

(Second Embodiment)
The second embodiment will be described with reference to FIGS. Compared with the stencil printing apparatus of the first embodiment, the second embodiment can use an emulsion ink corresponding to uncoated paper in addition to the active energy ray-curable ink. The point that the ink type detection means for detecting the type of ink is newly used in relation to the above, and the control configuration shown in FIG. 10 for performing the special plate making described later is used instead of the control configuration shown in FIG. Mainly different. The configuration of the second embodiment other than these differences is the same as that of the first embodiment. In other words, the second embodiment also has the characteristic configuration (configuration for forming tapered perforations) of the first embodiment shown in FIGS. 4 to 9 and Tables 1 and 2.

  The ink type detection means is means for detecting which of active energy ray-curable ink and emulsion ink is used in a narrow sense, and is a quick-drying property used in a third embodiment described later in a broad sense. It is a means for detecting all ink types used in stencil printing machines, including emulsion inks. In the following, in order to simplify the description, a narrowly-defined ink type detection means will be described.

  The printing drum 21 constitutes a drum unit that is unitized with an ink container and an ink supply pump (not shown), and can be attached to and detached from the apparatus main body 50 by a simple operation via an attaching / detaching means. . Then, an active energy ray curable ink printing drum unit provided with an active energy ray curable ink printing drum filled and mounted with an active energy ray curable ink and an emulsion ink as a non-active energy ray curable ink is filled. The emulsion ink printing drum unit including the mounted emulsion ink printing drum is set separately, and each is configured to be detachable from the apparatus main body 50 via the attaching / detaching means. Specific examples of the attaching / detaching mechanism or attaching / detaching mechanism (not shown) for selectively detaching the active energy ray curable ink printing drum unit and the emulsion ink printing drum unit from the apparatus main body 50 include, for example, actual implementation. The same plate cylinder support apparatus as shown in FIGS. 1 to 4 of Japanese Patent Laid-Open No. 61-85462 is employed. In addition, for example, holding means (36), gripping frame (50), front frame (51), and rear frame shown in FIG. 2 and FIG. (52) or the like may be used.

  The apparatus main body 50 in the vicinity of the attaching / detaching means detects the type of ink by detecting which of the active energy ray-curable ink printing drum unit or the emulsion ink printing drum unit is attached to the attaching / detaching means. An ink type detection sensor 213 shown only in FIG. 4 as an ink type detection means is provided. Specific examples of the ink type detection sensor 213 include, for example, a combination of an electrical connector (for example, male) disposed on the printing drum unit side and an electrical connector (for example, female) disposed on the apparatus main body 50 side. A notification control means arranged in the other control means 7 through the microcomputer peripheral circuit 2 electrically detects and judges the difference. This is the same as the drum unit ink type identification sensor (51) shown in FIG. 4 of Japanese Patent Application Laid-Open No. 2006-281658 according to Patent Document 2.

  The ink type detection means for detecting which of the active energy ray curable ink and the emulsion ink is used is not limited to the ink type detection sensor 213 but may be detected based on the following principle. That is, the active energy ray curable ink has higher cohesive force and tack value of the ink than the emulsion ink, regardless of the difference in ink temperature at the time of detection. Therefore, the ink viscosity is detected by using the ink viscosity detecting device described in Japanese Patent Application Laid-Open No. 10-44577 proposed by the present applicant, and which of the active energy ray-curable ink and the emulsion ink is used. It may be detected.

  This ink type detection means is provided on the downstream side in the rotation direction of the ink roller 25 in the vicinity of the ink roller 25 that supplies ink to the inner peripheral surface of the printing drum 21 and the doctor roller 26 that is disposed in proximity to the ink roller 25. An ink viscosity detection roller (not shown) arranged to come into contact with the ink application surface via an ink layer, roller driving means (not shown) for rotating the ink viscosity detection roller with a constant torque, and An ink viscosity detecting apparatus having a constant current power source (not shown) for supplying a constant current for rotating and driving a roller driving means with a constant torque, and a roller speed detecting means for detecting a rotation speed of the ink viscosity detecting roller. Thus, the viscosity of the ink is detected by detecting a change in the rotation speed of the ink viscosity detection roller. The roller speed detecting means includes an encoder disposed on the ink viscosity detecting roller, and a pulse generator disposed in proximity to the encoder and generating a pulse in cooperation with the encoder. The viscosity of the ink is detected based on the change in the pulse generated from the ink, and it is detected which of the active energy ray curable ink and the emulsion ink is used.

Compared with the control configuration shown in FIG. 4, the control configuration shown in FIG. 10 uses a control unit 2A in place of the control unit 2 and an ink type detection sensor 213 is newly connected to the input side of the control unit 2A. The point is mainly different. As shown in the figure, the microcomputer peripheral circuit 3A in the control unit 2A is similar to the microcomputer peripheral circuit 3 shown in FIG. 4 in that the CPU, ROM, RAM, internal timer, I / O port and A / D It comprises a converter, a microcomputer equipped with various counters, and the like.
The CPU of the microcomputer peripheral circuit 3A has arithmetic and control functions, and comprehensively controls the image processing unit 4, the thermal head drive control unit 5A, and other control means 7. In the ROM of the microcomputer peripheral circuit 3A, an operation program and related data for exhibiting the above functions of the microcomputer peripheral circuit 3A are stored in advance. The RAM of the microcomputer peripheral circuit 3A temporarily stores data from various sensors and calculation results of the microcomputer peripheral circuit 3A.
The thermal head drive control unit 5A is different from the thermal head drive control unit 5 shown in FIG. 4 only in that it has applied energy changing means, energization timing changing means, and plate making method selection means. It goes without saying that the microcomputer peripheral circuit 3A and the thermal head drive control unit 5A have a function as the first control means in the first embodiment.

The energization timing changing means and the plate making method selection means of the microcomputer peripheral circuit 3A and the thermal head drive control unit 5A are each heating element of the thermal head 10 according to the black pixel data signal sequentially transmitted from the image processing unit 4. The perforations formed in the film of the master 12 by the heat-generating driving of the odd-numbered bits corresponding to the odd-numbered 9 and the even-numbered bits corresponding to the even-numbered each heating element 9 are respectively formed on different rows in the main scanning direction; The individual heating elements 9 of the thermal head 10 are controlled so that the perforations formed in the film of the master 12 by the heat generation driving of the adjacent odd and even bits are not adjacent to each other in the same row in the main scanning direction. It functions as a second control means.
The black pixel and white pixel data signals sequentially transmitted from the image processing unit 4 correspond to the heating elements 9 arranged in a line in order from one end to the other end of the thermal head 10 in the main scanning direction. Since the one-to-one assignment is made in advance, the odd-numbered bits (odd-numbered heating elements 9) and even-numbered bits (even-numbered heating elements 9) of the thermal head 10 are unambiguous corresponding to the data signals of black pixels and white pixels. Will be determined.

The energization timing changing means of the thermal head drive control unit 5A has a function of making the energization timings for the odd and even bits of the thermal head 10 different.
The applied energy changing means of the thermal head drive control unit 5A has a function of changing the applied energy applied to the odd bits and even bits of the thermal head 10.
In addition, the notification control means in the control means 7 is based on the signal from the ink type detection 213, when the ink to be used (active energy ray curable ink / emulsion ink) is not suitable for coated paper or uncoated paper. It has a function of controlling the LCD screen (display / notification means) of the touch panel 98 so as to display / notify it.
Note that the control configuration shown in FIG. 10 is merely an example of the present embodiment. For example, a control configuration in which the microcomputer peripheral circuit 3A is incorporated in the thermal head drive control unit 5A and integrated may be used.

Next, with reference to FIGS. 11A and 11B, a description will be given of a perforation pattern that is melt perforated on the film of the master 12 by the thermal head 10 of the stencil printing apparatus in the present embodiment. FIG. 11A is a schematic perforation pattern formed on the film of the master 12 when the special plate making mode is executed by the second control unit of the present embodiment (the present invention), and FIG. It is a rough perforation pattern formed in the film of master 12 'at the time of normal plate-making mode execution by the 2nd control means of an embodiment (comparative example), and both have extracted the state in a solid part. 11 and 16, etc., in order to distinguish the master 12 ′ obtained by executing the normal plate making mode from the master 12 obtained by executing the special plate making mode, As long as it is 12 '.
Both of the perforation patterns are perforated and made under the sub-scan feed resolution conditions of the thermal head 10 and the plate making unit 1 of the following specifications. When executing both modes, the master 12 uses the same specifications detailed in the first embodiment, and the environmental conditions such as temperature and humidity are the same.
Thermal head specifications: 600 dpi (thin film type and flat type, heating element is rectangular)
Sub-scan feed resolution (feed pitch): 600 dpi
Image pattern (perforation pattern): Solid

  In FIG. 11A, reference numeral 100 denotes a punched portion where the film of the master 12 is melted and punched by the thermal head 10. In the figure, 101 indicates a line that is melt-pierced by the heating element 9 with odd bits of the thermal head 10, and 102 indicates a line that is melt-pierced by the heating element 9 with even bits of the thermal head 10. Yes. Reference numeral 105 denotes a resolution pitch in the main scanning direction S of the thermal head 10 to be used. 103 is the pitch in the sub-scanning direction Y of the line 101 that is melt-drilled by the heating element 9 with odd-numbered bits of the thermal head 10, and 104 is melt-drilled with the odd-numbered bit and even-bit heating element 9 of the thermal head 10. The pitch difference in the sub-scanning direction Y is shown respectively.

  A characteristic of the perforated state in FIG. 11 (a) is that the perforation pattern is arranged like a turtle shell when viewed broadly, and is regularly arranged. It is unique. In FIG. 11A, the pitch difference 104 in the sub-scanning direction Y (master transport direction Y) between the odd-numbered bit and the even-numbered bit in the heat generating member 9 is a state in which the heat generating member 9 in the thermal head 10 is melted and perforated. The resolution pitch 105 in the main scanning direction S of the thermal head 10 is ½.

Next, a conventional perforated state as a comparative example shown in FIG. In FIG. 11B, 100 ′, 103 ′, and 105 ′ correspond to 100, 103, and 105 in FIG. In FIGS. 11A and 11B, each rectangular frame surrounded by a broken line indicates one pixel (hereinafter the same).
In the perforated state shown in FIGS. 11 (a) and 11 (b), a spacing portion is formed between the perforations 100 and between the perforations 100 ′ and is independently perforated. In addition, the perforated state shown in FIG. 11A is characterized in that the remaining width dimension between adjacent perforations 100 of the film is wider than the thickness of the thermoplastic resin film. By the way, when the thickness of the thermoplastic resin film of the master 12 used is 3.5 μm, the remaining width dimension when the thermoplastic resin film is melt-pierced is the narrowest width adjacent in the sub-scanning direction Y. The width is wider than 3.5 μm.

  Next, with reference to FIG. 12, a driving method for melting and perforating with each heating element 9 of the thermal head 10 will be described. The figure schematically shows the energization timing of the odd-numbered bits and even-numbered bits in each heating element 9 in the thermal head 10. Basically, the energization timing changing means of the thermal head drive controller 5A energizes the odd bits and even bits at different timings. As described above, when the thermal head 10 is driven, a DATA signal for printing on the thermal head 10, a CLK signal for transferring this DATA signal to a driver IC provided in the thermal head 10, and a driver Four signals are basically required: a LATCH signal for latching the DATA signal transferred to the IC, and an STB signal for energizing the thermal head 10.

  In FIG. 12, for the sake of easy understanding, the signal is shown by being divided into odd bits for odd bits and even bits for even bits. What is characteristic in the figure is that the energization timings of odd bits and even bits are different. Actually, the thermal head 10 is often divided into several blocks and driven to generate heat. In this case, control is performed separately for odd bits and even bits even if the blocks are divided, regardless of the control for each block. In addition, the odd-numbered bits and even-numbered bits may be controlled in the block, or the driver IC itself in the thermal head 10 may be divided into odd-numbered bits and even-numbered bits. I do not care. What is important in this embodiment (the present invention) is to prevent odd bits and even bits from being arranged in a line in the main scanning direction S. Even in the perforated state in the drive division of the thermal head 10, the pitch difference 104 in the sub-scanning direction Y (master transport direction Y) between the odd-numbered bit and the even-numbered bit in the heating element 9 is in the main scanning direction S of the thermal head 10. It goes without saying that the resolution pitch 105 is ½.

  A perforation pattern that can be formed in the present embodiment will be described with reference to FIG. In the figure, as a driving method for melting and perforating with each heating element 9 of the thermal head 10, the energization energy when driving the odd and even bits in each heating element 9 is different, that is, the thermal head shown in FIG. The energizing energy (for example, energizing pulse width) applied to the even-numbered heating element 9 is made smaller than that of the odd-numbered bit by the applied energy changing means of the drive control unit 5A. That is, the size (diameter) of the perforation 106 formed by even bits is smaller than the size (diameter) of the perforation 100 formed by odd bits. By obtaining such a perforated state, the effect of smoothing the printed state at the time of fine lines can be obtained.

Next, the operation of this embodiment executed under the instruction of the CPU of the microcomputer peripheral circuit 3A of the control unit 2A shown in FIG. 10 will be described with reference to the flowchart of FIG. In this operation description, only the part related to the present invention will be described, and the other parts are well known and will be omitted. In the figure, the active energy ray curable ink is abbreviated as “active energy curable ink”.
First, in step S1 shown in FIG. 14, it is determined whether the plate making operation or the printing operation. When the plate making operation is executed, the process proceeds to step S2, and the coated paper setting key 131 of the coated paper / non-coated paper setting means (coated paper / non-coated paper separate plate making mode selection means) described above with respect to the paper to be used or uncoated. The paper setting key 132 is touched for setting. When uncoated paper is set with the uncoated paper setting key 132, the process proceeds to step S3, and the ink type detection sensor 213 detects whether the printing drum is filled or loaded with emulsion ink or active energy curable ink. To determine the ink type.
On the other hand, when the coated paper is set with the coated paper setting key 131, the process proceeds to step S7, and either the emulsion ink or the active energy curable ink is filled and mounted by the ink type detection sensor 213 as in step S3. The ink type is determined by detecting whether the printing drum is present.

In step S3 and step S7, there are three types of modes to be selected, and the plate making settings are classified as follows. That is,
Normal plate-making mode: This is a case where uncoated paper is set and emulsion ink is detected, and is a mode in which punching and plate-making operations are executed by the second plate control method using the normal plate-making (conventional plate-making) method (step S4).
Special plate making mode: uncoated paper setting and active energy curable ink, or coated paper setting and active energy curable ink detection, and the perforated state in this embodiment (the present invention), that is, the first The perforations are formed on different rows in the main scanning direction S by heat generation driving of the odd-numbered bits and even-numbered bits of each heating element 9 in the thermal head 10 by the control means 2 and heat is generated by the adjacent odd-numbered bits and even-numbered bits. This is a mode in which a perforation state in which the perforations are not adjacent to each other on the same line in the main scanning direction S by driving is obtained (step S8).
No plate making mode: This is a case where coated paper is set and emulsion ink is detected. On the LCD screen of the touch panel 98 shown in FIG. 3, a warning message “Preventing plate making with this combination” is displayed / notified. In this mode, the plate making operation is stopped (step S9, step S10). This is because emulsion ink is ink that relies on penetrating drying, and in the case of coated paper, ink penetration cannot be obtained. Therefore, in this combination, the ink cannot be fixed and cannot be used as a printed matter, so that the plate making operation is stopped. Here, the above three types of mode settings are initial settings in the present embodiment (the present invention) and can be changed. The three types of plate making mode settings are made by the plate making method selection means of the thermal head drive controller 5A shown in FIG.

  Next, when the plate making is completed with the contents of the normal plate making mode or the special plate making mode (step S6) and the flow proceeds to the printing operation, the flow is omitted, but printing is performed or a warning is issued. That is, even when the printing operation is executed, the print mode corresponds to the non-plate-making mode in the case of setting the coated paper and detecting the emulsion ink, and the warning display “ A display / notification of “printing is not possible with this combination” is performed, and the printing operation is stopped (non-printing mode). This is because emulsion ink is ink that relies on penetrating drying, and in the case of coated paper, ink penetration cannot be obtained. Therefore, in this combination, the ink cannot be fixed and cannot be used as a printed matter, and the printing operation is stopped.

  Next, with reference to FIG. 15, a description will be given of a first embodiment relating to plate making / printing executed in the special plate making mode by the second control means and in the conventional normal plate making mode by the second control means. In this example, the punching state (perforation pattern) obtained by executing the conventional normal plate-making mode, the printing state when printing on the coated paper, and the execution of the special plate-making mode of the present embodiment (the present invention) are performed. A comparison will be made between the obtained perforated state and the printed state when printed on coated paper, and printing wrinkles due to floating of the pre-printed master generated during printing with a combination of active energy ray-curable ink and coated paper will be described.

  The photograph shown in FIG. 15 shows a perforated state (perforated pattern) when a solid image of 33 × 33 mm is perforated and made and a printed state when printed on coated paper. The photograph shown on the left side of the figure is a perforated state (perforated pattern) obtained by a combination of a coated paper and an active energy ray-curable ink in a conventional normal plate-making mode, and a printed matter printed on the coated paper. A printed matter that has been completely fixed using the active energy ray curable fixing device 201 shown in FIG. On the other hand, the photograph shown on the right side of the figure is printed on the perforated state (perforated pattern) obtained by combining the coated paper and the active energy ray-curable ink in the special plate making mode of the present embodiment (the present invention) and the coated paper. This is a printed matter that has been completely fixed using the active energy ray curable fixing device 201. Specifically, the active energy ray curable fixing device 201 uses an ultraviolet irradiation fixing device.

An outline of common plate making / printing conditions for the above plate making / printing is shown below. Both were carried out under the same printing pressure conditions.
Environmental conditions: temperature 23 ° C, humidity 41% RH
Plate making resolution: resolution in the main scanning direction of the thermal head ... 600 dpi, resolution pitch (feeding pitch) in the sub-scanning direction of the master ... 600 dpi
Image pattern (perforated pattern): Solid Master used: “Type I master” manufactured by Ricoh Co., Ltd. Thermoplastic resin film, one-layer porous resin film and porous support described in JP-A-10-147075 And a master used in the first embodiment. The film 12-1 shown in FIG. 5 has a thickness Fh of 3.5 μm, and the porous resin film 12-2 shown in FIG. 8 has an application amount (attachment amount, basis weight) of 1.2 g / m ^2. Using.
Ink used: An active energy ray curable ink for stencil printing, which was experimentally produced for this experiment, and an ultraviolet curable ink was used.
Printing paper: Mitsubishi paper pearl coated paper 68k
Stencil printing machine: "Saterio A650 modified product" manufactured by Ricoh Co., Ltd.

  The left side of FIG. 15 printed under the above conditions is the above-mentioned coated paper using a perforated master plate obtained by combining the coated paper and the active energy ray-curable ink in the conventional normal plate-making mode. Since the printed matter is a printed matter that has been completely fixed using the active energy ray curing fixing device 201, a white stripe-like image defect occurs in the horizontal direction of the solid image in question. On the other hand, the right side of FIG. 15 shows a master in a perforated state obtained by a combination of the coated paper and the active energy ray-curable ink in the special plate making mode of the present embodiment (the present invention). Since the printed matter is printed on the above-mentioned coated paper using the active energy ray curing fixing device 201 and is completely fixed, an image having no problem in the solid image is obtained. It can be seen that have been.

  The reason why print wrinkles that cause white streak-like image defects occurs is as follows. First, coated paper has higher smoothness than non-coated paper, so the adhesion between the paper and the master is high, and second, active energy ray curing. In general, the ink has a higher cohesive force and tack value than the above-described emulsion ink, and therefore, the adhesion between the paper and the master is increased. Therefore, during printing, the solid part is gradually pulled to the rear side of the master that has been made, that is, the discharge rear side of the printed image. It was confirmed by experiment that the master was slackened and creased and creased to cause printing wrinkles (white streak-like images) due to the floating of the master. Such a printing wrinkle is a serious problem in a stencil printing apparatus, and is also an unacceptable defect.

  However, in the present embodiment (the present invention), the perforation pattern to be melted and perforated by each heating element of the thermal head is mainly perforation formed on the film by the heat generation driving of the odd and even bits of each heating element of the thermal head. Each perforation formed in a different line in the scanning direction and formed in the film by heat generation driving of adjacent odd and even bits is not adjacent to the same line in the main scanning direction. . Accordingly, as shown in FIG. 17, the plate making obtained by the special plate making mode of the present embodiment (the present invention) as shown in FIG. 17 is compared with the master 12 ′ having been made by the conventional normal plate making mode as shown in FIG. In the completed master 12, the area of the remaining film portion (the area of the non-plate-making image portion) excluding the portion where the perforations 100 are formed can be widened in the main scanning direction S, so that it is rigidly resistant to bending, folding, etc. in the main scanning direction S. In addition, considering the lines shown by thick broken lines, the number of perforations is reduced, and the adhesion between the paper and the master is weakened as described above. As a result, the effect of preventing the occurrence of printing wrinkles in the solid portion is reduced. can get.

  As described above, according to the present embodiment (the present invention), the basic effects of the first embodiment become significant. That is, according to the present embodiment (the present invention), in addition to the basic effects of the first embodiment, the ink used in the stencil printing apparatus is an emulsion ink or an active energy ray-curable ink for stencil printing. Even in the case of uncoated paper (quality paper, etc.) or coated paper, a stencil printing device that achieves optimal print image quality without causing printing wrinkles and master deviation by the master is realized. Can be provided. Further, the effects described in the above-described effect column and the like are also exhibited in this embodiment.

(Third embodiment)
A third embodiment will be described with reference to FIGS. 18 and 19. Compared with the stencil printing apparatus of the first embodiment, the third embodiment uses a quick-drying emulsion ink instead of the active energy ray curable ink used in the stencil printing apparatus. Accordingly, as shown in FIG. 19, a screenless plate cylinder 35 in which a mesh screen 36 as an ink diffusing member is removed from a plate cylinder 35 provided on the outer periphery of the printing drum 21, and the active energy shown in FIG. The main difference is that the stencil printing apparatus shown in FIG. The configuration of the third embodiment other than these differences is the same as that of the first embodiment. That is, the third embodiment also has the characteristic configuration (configuration for forming tapered perforations) of the first embodiment shown in FIGS. 4 to 9 and Tables 1 and 2.

  Here, the quick-drying emulsion ink is also described in the claims of Japanese Patent No. 3254652, but the resin component is increased among the components of the emulsion ink used conventionally, Means ink that is easily fixed (cured) on paper. In this ink, the evaporation component of the ink after printing evaporates, the resin is sufficiently dried, and the pigment is fixed (fixed / cured) on the paper by the dried resin. Therefore, it is not necessary to provide the active energy ray curable fixing device 201 shown in FIG. Hereinafter, in the third embodiment, “ink” means a quick-drying emulsion ink unless otherwise specified.

  As described in the column of the problem to be solved by the invention, the fast-drying emulsion ink is cured when the evaporation component is evaporated. In particular, the ink adhering to the outer periphery of the plate cylinder 35 has a large surface area, so that the evaporation component tends to evaporate. For this reason, the mesh screen made of fine polyester (# 300 to # 450 with 300 to 450 meshes per inch) disposed and wound around the outer periphery of the plate cylinder 35 is particularly clogged. Easy to wake up.

Therefore, as shown in FIG. 18A, in the first embodiment, the perforated area Sk of the K-side film 12-1 in the melt perforated portion 28 of the master 12 shown in FIG. By combining with taper perforation that makes the melt spread area Sf of the surface less than or equal to 1/2, the portion where the quick-drying emulsion ink evaporates on the outer peripheral surface of the plate cylinder is reduced, so that clogging of the mesh screen can be suppressed. .
Furthermore, as shown in FIG. 19 (a), the quick-drying emulsion ink is diffused by the effect of the taper perforation, so that it is not necessary to diffuse the ink with a mesh screen. Therefore, as shown in FIG. 19A, even if the mesh screen 36 wound on the outer peripheral surface of the conventional plate cylinder 35 as a comparative example shown in FIG. The problem that the hole of the trunk 35 appears in the image is eliminated.
FIG. 18B shows a cross-sectional state of the melt-piercing portion 28 ′ as normal drilling in the master 12 of the conventional example as a comparative example.

  Therefore, according to the present embodiment (the present invention), the effects described in the above-described effect column and the like are also exhibited in the present embodiment.

In the narrow sense, the above-mentioned “printed medium” naturally includes not only coated paper but also uncoated paper including high-quality paper, plain paper, postcards, etc., and in a broad sense, a resin film sheet or Also included are metal sheets, glass sheets, and the like.
As described above, the present invention has been described with respect to specific embodiments. However, the technical scope disclosed by the present invention is not limited to those exemplified in the above-described embodiments and the like. It will be apparent to those skilled in the art that various embodiments, modifications, and examples can be configured within the scope of the present invention in accordance with the necessity and application.

1 is a schematic front view of a stencil printing apparatus showing a first embodiment and the like of the present invention. It is a front view which shows the whole structure of the stencil printing apparatus main body of FIG. It is a top view of the operation panel used for the stencil printing apparatus main body of FIG. It is a block diagram which shows the control structure of the principal part of the stencil printing apparatus which concerns on 1st Embodiment. It is sectional drawing explaining the structure of the master used for 1st Embodiment, and the piercing | piercing state of the fusion | melting perforation part in the thermoplastic resin film. It is a figure explaining the relationship between the thickness and area ratio of the thermoplastic resin film of a master used for 1st Embodiment. (A) is a simplified cross-sectional view for explaining that the spread of ink is increased by setting the area ratio of the melt perforated part in the master used in the first embodiment to 0.5 or less (tapered perforation). , (B) is an area ratio of the melt perforated part in the master of the comparative example is 0.6 or more, and the cross section thereof becomes a perforated state close to a straight, so that the ink spread is compared with that shown in (a). FIG. (A) explains that the ink passage resistance is reduced by reducing the coating amount of the porous resin film in the master used in the first embodiment (1.0 to 1.9 g / m ² ). (B) illustrates that the ink passage resistance is increased by increasing the coating amount of the porous resin film in the master of the comparative example than that in the first embodiment. It is a simplified sectional view. (A) reduces the amount of the porous resin film applied to the master used in the first embodiment (1.0 to 1.9 g / m ² ), thereby reducing the stress on the master and making it difficult to tear. FIG. 6B is a simplified cross-sectional view illustrating the fact that the amount of application of the porous resin film in the master of the comparative example is larger than that in the first embodiment, so that the stress on the master increases and tears simultaneously. It is a simple sectional view explaining becoming easy. It is a block diagram which shows the control structure of the principal part of the stencil printing apparatus which concerns on 2nd Embodiment. (A) is a plan view when the perforated state of a master that has been made by the special plate making mode of the second embodiment (the present invention) is viewed from the film side, and (b) is a conventional normal plate making mode. It is a top view when the perforated state of the master made by platemaking obtained by the above is viewed from the film side. It is a timing chart of each signal transmitted to the thermal head of a 2nd embodiment. It is a top view when the perforation state of the master made by plate making obtained when energizing energies are made different from the film side regarding the perforation pattern that can be formed by the special plate making mode of the second embodiment. It is a flowchart showing the plate making operation | movement of 2nd Embodiment. A photograph showing Example 1 on the left side in the figure shows a master perforation state obtained by a conventional normal plate-making mode and a printing state when printed on coated paper using the master perforation state on the right side. These are photographs showing the punched state of the master obtained by the special plate making mode of the second embodiment (the present invention) and the printed state when printed on the coated paper using this. It is a figure explaining the area of the remaining width (non-image part) between the adjacent perforations in the main scanning direction when the master after completion of plate making obtained by the conventional normal plate making mode is bent. The area of the remaining width (non-image part) between adjacent perforations in the main scanning direction when the perforated state of the master that has been made by the special plate making mode of the second embodiment (the present invention) is bent. It is a figure explaining. (A) is a plane for explaining that the portion where the quick-drying emulsion ink evaporates on the outer peripheral surface of the plate cylinder is reduced by combining with the taper drilling of the first embodiment in the third embodiment. FIG. 4B is a developed sectional view, and FIG. 5B is a developed sectional view for explaining the sectional state of the melt drilled portion as the normal drilling in the master of the conventional example. (A) is sectional drawing developed on the plane for demonstrating the cross-sectional state of the preprinted master wound by the screenless plate cylinder outer peripheral surface in 3rd Embodiment, (b) is a prior art example. It is sectional drawing developed on the plane for demonstrating the cross-sectional state of the pre-printed master wound by the mesh screen currently wound by the plate cylinder outer peripheral surface.

Explanation of symbols

1 Plate making section (plate making equipment)
2, 2A control unit 3, 3A microcomputer peripheral circuit (constituting first and second control means)
4 Image processing unit 5, 5A Thermal head drive control unit (constituting first and second control means)
7 Other control means (notification control means)
9 Heating element (heating element)
10 Thermal head (plate making means)
DESCRIPTION OF SYMBOLS 11 Master feed motor 12 Master 12-1 Thermoplastic resin film 12-2 Porous resin film 12-3 Porous fiber film (porous support body)
14 Platen roller 21 Printing drum 23 Press roller (pressing means)
28 Melting perforation part 35 Plate cylinder 36 Mesh screen (ink diffusion member)
62 Paper (Printed media, sheet-like recording media)
90 Operation panel 98 Touch panel 100, 100 ', 106 Perforation formed in master film 101 Line drilled by odd bits of thermal head 102 Line drilled by even bits of thermal head 103 Perforated by odd bits of thermal head 104 Sub-scanning direction pitch of the line 104 Pitch difference in the sub-scanning direction when punching with odd and even bits of the thermal head 105 Resolution pitch in the main scanning direction of the thermal head 131 Coated paper setting key (coated paper / non-coated paper) Setting method)
132 Uncoated paper setting key (Coated paper / uncoated paper setting means)
DESCRIPTION OF SYMBOLS 200 Stencil printing apparatus 201 Active energy ray hardening fixing apparatus 202 Paper supply part 203 Paper supply stand 204 Paper discharge stand 213 Ink type detection sensor (ink type detection means)
F Surface of the thermoplastic resin film facing the heating element of the thermal head Fh Thickness of the thermoplastic resin film K Surface of the thermoplastic resin film facing the porous resin film Sk Surface of the thermoplastic resin film facing the porous resin film Perforated area of Sf The surface of the thermoplastic resin film that melts and spreads on the surface facing the heating element of the thermal head Sp The surface of the porous resin film that faces the melting and spreading area of the surface of the thermoplastic resin film that faces the heating element of the thermal head Area ratio of the perforated area of the thermoplastic resin film on the finished surface S Main scanning direction Y Sub-scanning direction / Master transport direction

Claims (7)

A thermal head having a large number of heating elements arranged in the main scanning direction is brought into direct contact with the thermoplastic resin film side of the master having at least a thermoplastic resin film and a porous resin film, and the main scanning is performed. Perforating in accordance with the image signal by melting and perforating the thermoplastic resin film by position-selective heat generation driving of each of the heating elements according to the image signal while relatively moving the master in the sub-scanning direction orthogonal to the direction. A pattern-prepared master on which the perforation pattern is formed is wound around a plate cylinder provided on the outer periphery of the printing drum, and ink is supplied from the inner peripheral side of the plate cylinder. In the stencil printing apparatus for forming an ink image corresponding to the image signal on the printing medium with the ink that has oozed out,
The thermoplastic resin film has a thickness of 2.5 to 5 μm,
The thermal head of the thermal head so that the perforated area of the thermoplastic resin film on the surface facing the porous resin film is ½ or less of the melt spread area of the surface of the thermoplastic resin film facing the thermal head. A stencil printing apparatus comprising first control means for controlling perforation energy supplied to each of the heating elements. In the stencil printing apparatus according to claim 1,
The stencil printing apparatus, wherein the coating amount of the porous resin film is 1.0 to 1.9 g / m ² . In the stencil printing apparatus according to claim 1 or 2,
A stencil printing apparatus, wherein the ink is an active energy ray curable ink. In the stencil printing apparatus according to any one of claims 1 to 3,
Perforations formed in the thermoplastic film by heat generation driving of odd bits corresponding to odd numbers of the heating elements and even bits corresponding to even numbers of the heating elements are respectively formed on different rows in the main scanning direction. And the thermal heads so that the perforations formed in the thermoplastic resin film by the heat generation driving of the adjacent odd and even bits are not adjacent to each other in the same row in the main scanning direction. A stencil printing apparatus comprising a second control means for controlling the stencil. In the stencil printing apparatus according to any one of claims 1 to 4,
The printing medium includes a plate making mode selection setting unit that can select and set a plate making mode for executing a plate making operation corresponding to coated paper and non-coated paper, respectively. Stencil printing device. In the stencil printing apparatus according to claim 1 or 2,
A stencil printing apparatus, wherein the ink is a fast-drying emulsion ink. In the stencil printing apparatus according to claim 6,
A stencil printing apparatus, wherein the ink diffusing member is removed from the plate cylinder.

Images