JP2008307829A - Stencil printing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stencil printing device that can prevent the generation of a printing crease and displacement of a mater caused by the float of the master, and can obtain the most suitable printing image quality regardless of ink to be used being either an emulsion ink or an active energy radiation hardenable ink or regardless of any other conditions. <P>SOLUTION: The stencil printing device is so designed that a perforation bored on a film of the master by heat generated by odd bits and heat generated by even bits of a thermal head 10 are formed in lines having different main scan directions, and the device has a first control means that executes a special plate making mode whereby plate making motion is performed so that each perforation bored at the film by the heat generated by odd bits and the even bits which adjoin each other does not line up on the same line having the same main scan direction S and a second control means that controls a master conveying means 19 adjusting master conveying pitches to correspond to resolution feed pitches of the sub scan direction established from signals of the sub scan direction resolution setting key 29. <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 material 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, mesh screen (not shown), and the punched area of the master, and transferred and transferred to the paper. To get.
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 a general stencil printing apparatus, 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, the master of the plate-making has been completed. There has been a problem that a printing wrinkle or a master shift that causes a white streak-like image defect due to floating occurs.

  Therefore, the present invention has been made in view of the above circumstances, and any environment and plate making can be used even if the ink used in the stencil printing apparatus is an emulsion ink or an active energy ray curable ink for stencil printing. Even under printing conditions (for example, ambient temperature, thermal head temperature, ink temperature, ink type, uncoated paper / coated paper as the paper type of the printing medium, etc.), and due to increased resolution in the sub-scanning direction, plate making It is a main object to realize and provide a stencil printing apparatus that can obtain an optimal print image quality without causing printing wrinkles (white streak-like image defects) due to the floating of the already master and deviation of the master.

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 brought into direct contact with the thermoplastic resin film side of a master having a thermoplastic resin film, and While moving the master in the sub-scanning direction orthogonal to the scanning direction, the image signal is obtained by melting and perforating the thermoplastic resin film by position-selective heat generation driving of each heating element according to the image signal. A perforated pattern corresponding to the perforated pattern is obtained, and a preprinted master on which the perforated pattern is formed is wound around the outer peripheral surface of the printing drum, ink is supplied from the inner peripheral side of the printing drum, and bleeding is performed through the perforated pattern. An ink image corresponding to the image signal is formed on the printing medium with the ink that has come out, and an active energy ray-curable ink is used as the ink. In a stencil printing apparatus capable of printing on uncoated paper and coated paper as the printing medium and capable of complete fixing, an odd number corresponding to an odd number of each heating element and an even number of each heating element The perforations formed in the thermoplastic resin film are formed on different rows in the main scanning direction by the heat generation driving of the even-numbered bits, and the heat generation of the adjacent odd-numbered bits and the even-numbered bits. First control means for executing a special plate-making mode for making a master so that the perforations formed in the thermoplastic resin film by driving are not adjacent to each other in the same row in the main scanning direction; and Master transport driving means for driving the master transport means to move at a feed pitch, and resolution feed pitch in the sub-scanning direction. On the basis of the signal from the sub-scanning direction resolution setting means when executing the special plate-making mode, and the sub-scanning direction resolution setting means capable of setting the thermal head less than the resolution pitch in the main scanning direction of the thermal head. And a second control means for controlling the master transport driving means so as to change the feed pitch corresponding to the set resolution feed pitch in the sub-scanning direction.

  According to a second aspect of the present invention, in the stencil printing apparatus according to the first aspect, the thermoplastic head film is perforated independently of each other by the thermal head.

  According to a third aspect of the present invention, in the stencil printing apparatus according to the first or second aspect, as a perforated state of the thermoplastic resin film by the thermal head, a remaining width dimension between adjacent perforations of the thermoplastic resin film Is wider than the thickness of the thermoplastic resin film.

  According to a fourth aspect of the present invention, in the stencil printing apparatus according to any one of the first to third aspects, a first applied energy change that makes the applied energy applied to the odd bit and the even bit different. It has the means.

  According to a fifth aspect of the present invention, in the stencil printing apparatus according to the fourth aspect, when the first applied energy changing means has at least two lines of resolution in the sub-scanning direction, the outer side of the line in the sub-scanning direction is outside. The applied energy is changed so that the size of the perforation located at the center is smaller than that of the perforation located near the center of the line in the sub-scanning direction.

  According to a sixth aspect of the present invention, in the stencil printing apparatus according to any one of the first to fifth aspects, a plate making / printing mode for executing plate making and printing operations respectively corresponding to the coated paper and the uncoated paper is provided. Based on the signals from the coated paper / non-coated paper separate plate making / printing mode setting means that can be set and the coated paper / non-coated paper separate plate making / printing mode setting means, the setting by the setting means And second applied energy changing means for changing the applied energy so as to obtain the optimum size of the perforations.

  A seventh aspect of the present invention is the stencil printing apparatus according to any one of the first to sixth aspects, wherein the environmental temperature detecting means for detecting the environmental temperature, the thermal head temperature detecting means for detecting the temperature of the thermal head, Ink temperature detecting means for detecting ink temperature, ink type detecting means for detecting ink type, ink type setting means for setting ink type, printing medium type detecting means for detecting type of printing medium, and printing medium type The applied energy applied to each of the heating elements of the thermal head is adjusted to a predetermined energy based on at least one of the printing medium type setting means for setting the print medium and a signal from the at least one means. And an applied energy adjusting means.

  The invention according to claim 8 is the stencil printing apparatus according to any one of claims 1 to 7, wherein a printing pressure variable means for changing a printing pressure when the printing medium is pressed against the printing drum; Environmental temperature detection means for detecting environmental temperature, thermal head temperature detection means for detecting the temperature of the thermal head, ink temperature detection means for detecting ink temperature, ink type detection means for detecting ink type, ink for setting ink type At least one of a type setting means, a printing medium type detecting means for detecting the type of the printing medium, a printing medium type setting means for setting the type of the printing medium, and a printing speed setting means for setting the printing speed And a printing pressure variable control means for controlling the printing pressure varying means so that the printing pressure becomes a predetermined printing pressure based on a signal from the at least one means. Characterized in that it has and.

  According to a ninth aspect of the present invention, in the stencil printing apparatus according to any one of the first to eighth aspects, a character mode for performing a plate making operation corresponding to a character image or the like and a photo for performing a plate making operation corresponding to a photographic image or the like. Based on a character / photo mode setting means for setting a mode and a signal from the character / photo mode setting means, each heating element of the thermal head is provided with an optimum size of the perforation for each mode. And a mode-specific applied energy changing means for changing the applied energy to be applied.

  A tenth aspect of the present invention is the stencil printing apparatus according to any one of the first to ninth aspects, wherein a printing pressure variable means for changing a printing pressure when the printing medium is pressed against the printing drum; Based on a character mode for performing a printing operation corresponding to a character image or the like and a character / photo mode setting means for setting a photo mode for performing a printing operation corresponding to a photograph image or the like, and a signal from the character / photo mode setting means, And a mode-specific variable printing pressure control means for controlling the printing pressure variable means so as to obtain the optimum printing pressure for each mode.

  The invention described in claim 11 is the stencil printing apparatus according to any one of claims 1 to 10, wherein the master includes the thermoplastic resin film and at least one porous resin film. And

  According to a twelfth aspect of the present invention, in the stencil printing apparatus according to any one of the first to eleventh aspects, perforations formed in the thermoplastic resin film by the heat generation driving of the heat generating elements are in the main scanning direction. Third control means for executing a normal plate making mode for making a master so as to be formed on the same line, both a special plate making mode by the first control means and a normal plate making mode by the third control means Is feasible.

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 the first aspect of the present invention, by the execution of the special plate-making mode by the first control means, the odd number bit corresponding to the odd number of each heating element of the thermal head and the even number corresponding to the even number of each heating element by the above configuration. The perforations formed in the thermoplastic resin film by the heat generation driving of the bits are formed in different rows in the main scanning direction, respectively, and the heat generation driving of the adjacent odd and even bits in the thermoplastic resin film. The master plate is made so that the perforations to be formed are not adjacent to each other in the same row in the main scanning direction, and the second control means sets the sub-scanning set based on the signal from the sub-scanning direction resolution setting means. Since the master conveyance drive means is controlled to change to a feed pitch corresponding to the resolution feed pitch in the scanning direction, active energy ray curing is performed. Print wrinkles that are mainly generated by the combination of ink (for example, UV curable ink) and coated paper can be prevented, and the resolution scanning pitch in the sub-scanning direction is set by the sub-scanning direction resolution setting means. When the resolution pitch is set to less than the direction, the reproducibility of fine lines and the like is improved, and a good print image can be obtained even when the coated paper is completely filled, thereby obtaining the optimum print image quality. It becomes possible.

  According to the second aspect of the present invention, the further effect of the first aspect of the invention can be obtained, and a master that is superior in the printing durability of the master when a large number of sheets are printed can be obtained.

  According to the third aspect of the present invention, as a perforated state of the thermoplastic resin film by the thermal head, the remaining width dimension between adjacent perforations of the thermoplastic resin film is wider than the thickness of the thermoplastic resin film. Therefore, the effect of the invention according to claim 1 or 2 is surely achieved.

  According to the fourth aspect of the present invention, the first applied energy changing means varies the applied energy applied to the odd-numbered bit and the even-numbered bit of the thermal head. It is possible not only to obtain the effects of the invention described in 1), but also to finely print fine lines and the like.

  According to the fifth aspect of the present invention, when the number of lines in the sub-scanning direction resolution is at least two, the first applied energy changing unit determines the size of the perforation located outside the line in the sub-scanning direction. Since the applied energy is changed so as to be smaller than that of the perforation located near the center of the line in the scanning direction, the outer perforation line in the sub-scanning direction can obtain more linearity. Print image quality can be obtained.

  According to the sixth aspect of the present invention, with the above configuration, the second applied energy changing means is set by the setting means based on a signal from the coated paper / non-coated paper separate plate making / printing mode setting means. Since the applied energy is changed so as to obtain an optimum perforation size, not only the effect of the invention according to any one of claims 1 to 5 can be obtained, but also uncoated paper and coated paper. In this case, more preferable print image quality can be obtained.

  According to the seventh aspect of the present invention, with the above configuration, the applied energy adjusting means includes an environmental temperature detecting means for detecting the environmental temperature, a thermal head temperature detecting means for detecting the temperature of the thermal head, and an ink for detecting the ink temperature. Temperature detecting means, ink type detecting means for detecting ink type, ink type setting means for setting ink type, printing medium type detecting means for detecting type of printing medium, and printing medium for setting type of printing medium The applied energy to be applied to each heating element of the thermal head is adjusted to a predetermined energy based on a signal from at least one of the type setting means, so that it can be used under any environment / printing condition. It is possible to reliably obtain the effect of the invention described in any one of the above.

  According to the invention described in claim 8, with the above configuration, the printing pressure variable control means includes an environmental temperature detecting means for detecting the environmental temperature, a thermal head temperature detecting means for detecting the temperature of the thermal head, and an ink for detecting the ink temperature. Temperature detecting means, ink type detecting means for detecting ink type, ink type setting means for setting ink type, printing medium type detecting means for detecting type of printing medium, printing medium for setting type of printing medium Based on a signal from at least one of the type setting means and the printing speed setting means for setting the printing speed, the printing pressure variable means is controlled so that the printing pressure becomes a predetermined printing pressure. Even under printing conditions, it is possible to reliably obtain the effects of the invention according to any one of claims 1 to 7.

  According to the ninth aspect of the present invention, the applied energy changing means for each mode changes the applied energy applied to each heating element of the thermal head so as to obtain the optimum perforation size for each mode. In addition to the effects of the invention according to any one of claims 1 to 8, it is possible to obtain suitable print image quality for image data in the plate-making mode for any manuscript. .

  According to the tenth aspect of the present invention, with the above-described configuration, the mode-specific variable printing pressure control means is adapted to obtain the optimum printing pressure for each mode based on the signal from the character / photo mode setting means. Since the variable means is controlled, not only the effect of the invention according to any one of claims 1 to 9 but also a print image quality more suitable than the effect of the invention according to claim 9 can be obtained. It becomes possible.

  According to the eleventh aspect of the invention, the master has the effect of the invention according to any one of the first to tenth aspects by including the thermoplastic resin film and at least one porous resin film. In addition, the smoothness of the master on the thermoplastic resin film surface is improved, the perforation defects are further reduced, and the ink dispersibility is also improved, so it is possible to obtain a more favorable print image quality. It becomes.

  According to the twelfth aspect of the invention, both the special plate-making mode by the first control means and the normal plate-making mode by the third control means can be executed. In addition to the effects of the described invention, it automatically determines which mode is executed in consideration of the combination of active energy ray curable ink (for example, ultraviolet curable ink) and uncoated paper or coated paper. Can be set automatically.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention including the best mode and examples for carrying out the invention will be described 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 a digital thermal stencil printing apparatus according to an embodiment of the present invention, and FIG. 2 mainly shows the overall configuration of the main body of the digital thermal stencil printing apparatus in FIG. Yes.
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. In the active energy ray curable fixing device 201, an active energy ray lamp, a motor for conveying a sheet, a belt, a suction 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 that of the UV irradiation device (2) as the ultraviolet irradiation device shown in FIG. 1 of JP-A-2006-281658 proposed by the applicant of the present application, 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 at the time of setting the normal plate making mode, which will be described later, as in the prior art will be described. The configuration relating to the special plate-making mode, which will be described later, and the operation different from the operation when setting the normal plate-making mode will be described in detail after this description.
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 discharging box 74 while being conveyed in the arrow direction Y1, and the so-called discharging 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 referred to as “below”) by the rotation of the separation roller 81, the front document transport roller pair 82a, 82b, and the rear document transport roller pair 83a, 83b. 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 8 shown in FIG. 4, the document transport motor sets the sub-scan feed pitch of the document 60 in the resolution (dot / dot). It is controlled to change to a predetermined sub-scan feed pitch corresponding to (inch).
The separation roller 81, the front document transport roller pair 82a and 82b, and the rear document transport roller pair 83a and 83b constitute a document transport unit that transports the document 60. The document transport motor is a document that rotationally drives the document transport unit. It functions as a conveyance driving means. The document conveying motor is included in the other output unit 28 shown in FIG.

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.
In the following description, it is assumed that the conventional plate making method is executed by the plate making method selection means provided in the thermal head drive controller 5. “Normal plate-making” or “normal plate-making mode” 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. This means a well-known plate making method formed on the same line in the main scanning direction. In the thermal head drive control unit 5, in addition to the first control means for executing “special plate making” or “special plate making mode” specific to the present embodiment, which will be described in detail later, the plate making method selection means On the basis of this signal, third control means for controlling the individual heating elements 9 of the thermal head 10 so as to execute the normal plate making mode 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 a variety of known controls, i.e., control, excluding the first and second applied energy changing means and energization timing changing means for performing the special plate making. Thermal history control by the thermal history control means disposed in the section 2, common drop correction control by the common drop correction control means, applied energy correction control by the applied energy adjustment means, applied energy correction control by the mode-specific applied energy changing means, etc. A digital image data signal (hereinafter simply abbreviated as “data signal” or “DATA signal”) as a signal for driving the thermal head is appropriately given, and various other controls are appropriately given by the control means 8. Clock signal (hereinafter also abbreviated as “CLK signal”), latch signal (hereinafter, “CLK signal”) A current signal (hereinafter also abbreviated as “STrobe signal” or “STB signal”) is generated and transmitted to the thermal head 10 via a thermal head drive circuit (not shown). The

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 8 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 front end of the master 12 having image information written therein is sent out toward the outer peripheral side 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, 2 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.

Here, the platen roller 14, the tension roller pair 15a, 15b, the reverse roller pair 17a, 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 The master feed motor 11 functions as a master transport driving unit that rotationally drives the master transport unit 19.
When the normal plate making mode is executed, the plate making unit 1 is set in advance so that the resolution in the sub-scanning direction Y when moving the master 12 in the sub-scanning direction Y is the same as the resolution of the thermal head 10. . It should be noted that setting of the sub-scanning direction resolution feed pitch by the sub-scanning direction resolution setting means is effective even in normal plate making.

  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. For example, a W / O type emulsion ink is preferred as the ink to be used when printing on uncoated paper such as high-quality paper if complete fixing is not required when the conventional normal plate-making mode is set. Used. 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

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, the printing pressure varying means, etc. will be described with respect to the special plate making mode unique to the present embodiment and the main part configuration related thereto.
As the master 12 currently used in the stencil printing apparatus shown in FIGS. 1 and 2, a porous support made of, for example, a thermoplastic resin film and Japanese paper fiber, synthetic fiber, or a mixture of Japanese paper fiber and synthetic fiber, etc. The thing of the laminate structure which bonded the body is mentioned. As the thermoplastic resin film, for example, a polyethylene terephthalate (PET) film is used. As the master 12, all known masters, that is, the thickness of the master 12 generally used in the stencil printing apparatus is in the range of 20 to 60 μm, and the thickness of the thermoplastic resin film among them is in the range of 20 to 60 μm. Is in the range of 1.0 to 2.5 μm.

  The master 12 is not limited to the above-described one, and may be a master in which the thickness of the porous support of the master 12 is reduced. For example, a synthetic fiber base master as described in JP-A-11-77949 (2) or a master having a thermoplastic resin film, at least one porous resin film and a porous support as described in JP-A-10-147075, that is, a thermoplastic resin film At least one layer of a master, or a thermoplastic resin film, in which a porous resin film made of resin is provided on one surface and a porous fiber film as a porous support made of a fibrous material is further laminated on the surface. A master composed of a porous resin film or a master composed substantially only of a thermoplastic resin film can also be used.

As shown in FIG. 2, an environmental temperature sensor 210 as environmental temperature detection means for detecting environmental temperature is disposed in the apparatus main body 50 in the vicinity of the upper portion of the plate discharging unit 70. Inside the printing drum 21, an ink temperature sensor 211 is disposed as an ink temperature detecting means that is disposed in the ink reservoir 27 forming portion of the ink supply means and detects the ink temperature. In addition, you may detect each said temperature not only directly but indirectly.
Further, a thermal head temperature detection sensor 212 as a thermal head temperature detection means for detecting the temperature of the thermal head 10 is disposed in the plate making unit 1. As the location of the thermal head temperature detection sensor 212, the same part as shown in FIG. 4 of Japanese Patent Laid-Open No. 2006-82358, that is, the surface of the heating element 9, for example, the heating element 9 surrounded by electrodes. Although it is desirable that the portion be close to the central surface portion, detection at that portion is almost impossible with the current technology, so here the thermal head substrate on the thermal head substrate mounted on the thermal head 10 is thermally The temperature of the main body of the head 10 is detected. However, the present invention is not limited to this, and it may be provided inside an aluminum heat radiating support called aluminum heat radiating plate constituting the thermal head 10.
As the environmental temperature sensor 210, the ink temperature sensor 211, and the thermal head temperature detection sensor 212, a thermistor having a desired sensitivity and reliability and being relatively small and inexpensive is preferably used. As long as the above advantages are not desired, other temperature detection means may be used.

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, the plate 12 has a function as a plate making means for heating and perforating the master 12 by position selective heating by heating a large number of heating elements. 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.
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.

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 a printing speed setting. A key 107 and the like are provided. The operation panel 90 also functions as an ink type setting unit, a printing medium type setting unit, a character / photo mode setting unit, a character / photo mode setting unit, a notification unit, and a coated paper / non-coated paper setting unit. It is arranged. 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 is a function for confirming / setting numerical values at various settings, the mode clear key 96 is a function for erasing / clearing various mode setting states, and the printing speed setting key 107 is a printing speed (for example, 60 to 120). Sheet / min: 60 to 120 rpm), and a function as a printing speed setting unit, and is pressed when each of these functions is to be exhibited. The printing speed setting key 107 includes a speed up key and a speed down key shown in the drawing, and a printing speed indicator composed of LEDs for lighting the set printing speed is disposed in the vicinity thereof.

The touch panel 98 is driven by an LCD (Liquid Crystal Display) drive circuit including a touch panel drive circuit (not shown), and displays various modes and various selection setting means (the above-described ink type setting means, printing medium) displayed on a known touch panel system. Type setting means, character / photo mode setting means, coated paper / non-coated paper setting means) are displayed in black and white reversed and can be selected and set.
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 capable of selectively setting a plate making / printing mode for executing a plate making and printing operation corresponding to coated paper and non-coated paper, respectively. It has a function as a print mode selection setting means, and specifically comprises a coated paper setting key 30 and an uncoated paper setting key 31 provided on the touch panel 98. The coated paper / non-coated paper setting unit also functions as a printing medium type setting unit that sets the type of printing medium. The non-coated paper setting key 31 is not limited to this, and for example, a key that can more specifically select and set PPC paper, high-quality paper, or the like may be provided.

  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.

On the touch panel 98, a resolution feed pitch in the sub-scanning direction for moving the master in the sub-scanning direction (hereinafter simply referred to as “sub-scanning direction resolution”, “sub-scanning feed resolution”, or “sub-scanning direction resolution feed pitch”). ) Is set less than the resolution pitch in the main scanning direction of the thermal head 10 (hereinafter, also simply referred to as “resolution of the thermal head 10”).
As the resolution in the sub-scanning direction, for example, when the resolution of the thermal head 10 is 600 dpi, a plurality of settings such as 800 dpi and 1200 dpi may be set, or only one resolution such as 800 dpi may be set. In the example of the present embodiment, in order to make it easy to understand by the operation described later, in the case of the thermal head 10 having a resolution of 600 dpi, a sub-scanning direction resolution setting key 29 for setting the sub-scanning direction resolution to 800 dpi is provided. Explain that it is. Then, it is assumed that when the sub-scanning direction resolution setting key 29 is not touched, it is initially set (initialized) to 600 dpi as the sub-scanning direction resolution similar to the resolution of the thermal head 10 and operates.

In addition to the above, the touch panel 98 includes, for example, an ink type setting key 32 for setting active energy ray-curable ink, and an ink type setting key for setting emulsion ink, for example, as ink type setting means for setting the ink type. 33 is arranged. The ink type setting keys 32 and 33 are not limited to these, and more specifically, keys that can be set for each ink type, such as black, red, and yellow, may be attached.
Further, the touch panel 98 has a character mode setting key 34 as a character / photo mode setting means for setting a character mode for performing a plate making / printing operation corresponding to a character image or the like, and a plate making / printing operation corresponding to a photographic image or the like. A photo mode setting key 35 as a character / photo mode setting means for setting a photo mode to be performed is provided.

  The coated paper / non-coated paper setting means, printing medium type setting means, sub-scanning direction resolution setting means, ink type setting means, character / photo mode setting means, etc. are not limited to those provided on the touch panel 98, For example, a dedicated key is provided, or a combination of one key and a plurality of LEDs is used to change the LED display each time the key is pressed. It may be set with a key.

The ink type detection means is means for detecting the ink type used in the stencil printing apparatus, including active energy ray curable ink and emulsion ink.
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. . 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 a color-specific emulsion as a non-active energy ray curable ink Separately set for each color emulsion ink printing drum unit equipped with a color emulsion ink printing drum filled and mounted with ink, each of which can be attached to and detached from the apparatus main body 50 via the attachment / detachment means. It is configured. Specific examples of the attaching / detaching mechanism or attaching / detaching mechanism (not shown) for selectively attaching / detaching the active energy ray-curable ink printing drum unit and the color-specific emulsion ink printing drum unit to / from the apparatus main body 50 include A plate cylinder supporting device similar to that shown in FIGS. 1 to 4 of Japanese Utility Model 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 whether it is an active energy ray-curable ink printing drum unit or a color-specific emulsion ink printing drum unit attached to the attaching / detaching means. An ink type detection sensor 213 shown only in FIG. 4 is disposed as an ink type detection means for detecting. 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 8 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 color-specific emulsion ink (for example, black ink, red ink, etc.) is used is not limited to the ink type detection sensor 213, but this application It consists of a combination of Hall element sensors (136, 137, 138) shown in FIG. 16 of Japanese Patent Application Laid-Open No. 2004-155170 proposed by the applicant and magnets (130, 131, 132) arranged in each drum unit. Ink type detection means (135) may be used, or detection based on the following principle. That is, the active energy curable ink has a higher cohesive force and tack value than the emulsion ink regardless of the difference in ink temperature at the time of detection. Therefore, the ink viscosity is detected using the ink viscosity detecting device described in Japanese Patent Application Laid-Open No. 10-44577 proposed by the applicant of the present application, and any of the active energy ray-curable ink and the color-specific 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.

Next, a printing pressure variable unit that changes the printing pressure when pressing the paper 62 as the printing medium against the printing drum 21 will be described. As the printing pressure varying means of this embodiment, printing pressure varying means for changing the printing pressure which is the pressing force of the press roller 23 against the printing drum 21 is used, which is shown in FIG. 3 of the above Japanese Patent Application Laid-Open No. 2004-155170. The same printing pressure variable means (20) as employed is employed.
That is, as shown in FIG. 3 of the above publication, the printing pressure varying means (20) is fixed to the apparatus main body frame (50) via a non-illustrated immovable member, and the worm (15) is attached to the output shaft. Paper conveyance is performed via a groove (not shown) formed in the apparatus main body frame (50) in which the printing pressure control motor (14) capable of forward / reverse rotation and the other end of the spring (6) are locked. A movable shaft (7) supported so as to be movable back and forth only in the front-rear direction of the direction (Y4) and having an internal thread formed on the inner peripheral portion thereof, and a male screw that engages with the female screw on the movable shaft (7) A rotatable rotating shaft (10) formed on the rotating shaft (10), a worm wheel (11) fixed to the rotating shaft (10) and constantly meshing with the worm (15), and a worm wheel (10) fixed to one end of the rotating shaft (10). 11) for detecting the rotational speed A coder (12) and a spring length detection sensor (13) which is attached to a position near the encoder (12) in the apparatus main body frame (50) via a non-illustrated immovable member and holds the encoder (12) at a predetermined interval. A light shielding plate (8) formed to project outward from the outer peripheral portion of the movable shaft (7), and a non-illustrated non-illustrated member at a position near the light shielding plate (8) in the apparatus main body frame (50). A printing pressure home position sensor (9) which is attached and detects the home position (position indicating the printing pressure standard state) of the encoder (12) by pinching the light shielding plate (8) at a predetermined interval. It is a well-known thing comprised mainly. The printing pressure control motor (14) controls the printing pressure of the press roller (103) against the printing drum (101) by changing the tension length of the spring (6), that is, changing the tension of the spring (6). It has a function as a drive source for changing.

The printing pressure varying means of this embodiment is substantially the same as the printing pressure varying means (20) with the reference numeral 520 obtained by adding a numerical value 500 to the printing pressure varying means (20) shown in FIG. It is expressed (see printing pressure variable means 520 shown in FIG. 4).
The printing pressure varying means 520 is not limited to this, and the pressing pressure varying means (130) shown in FIGS. 5 and 6 of Japanese Patent Application Laid-Open No. 2003-39802, including the case of an impression cylinder, for example, may also be used. Good.

With reference to FIG. 4, a control configuration for controlling mainly the plate making unit 1, the operation panel 90, and the printing pressure variable means 520 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 arithmetic and control functions, and each of them will be described later, an image processing unit 4, a thermal head drive control unit 5, a printing pressure variable control unit 6, a mode-specific printing pressure variable control unit 7, and other controls. The means 8 is comprehensively controlled. 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.

Further, the control unit 2 includes an environmental temperature detection unit capable of detecting an environmental temperature from a detection data signal (environment temperature detection information) related to the environmental temperature output from the environmental temperature sensor 210, and a thermal head temperature detection sensor 212. Thermal head temperature detection unit capable of detecting thermal head temperature from detection data signal (thermal head temperature detection information) related to output thermal head temperature, detection data signal related to ink temperature output from ink temperature sensor 211 An ink temperature detection unit capable of detecting the ink temperature from (ink temperature detection information) is provided.
Various detection units such as an environmental temperature detection unit, a thermal head temperature detection unit, and an ink temperature detection unit are configured to detect various temperatures using A / D conversion or the like.

The energization timing changing means and the plate making method selection means of the microcomputer peripheral circuit 3 and the thermal head drive control unit 5 correspond to each heating element of the thermal head 10 in accordance with the black pixel data signal sequentially transmitted from the image processing unit 4. The perforations formed in the film 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 heating elements 9 are formed on different rows in the main scanning direction and adjacent to each other. In order to execute the special plate making mode in which the master 12 is made so that the perforations formed in the film by the heat generation driving of the odd bits and the even bits are not adjacent to each other in the same row in the main scanning direction, It functions as a first control means for controlling the heating element 9.
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 5 has a function of making the energization timings for the odd and even bits of the thermal head 10 different.
The first applied energy changing means of the thermal head drive control unit 5 has a function of making different applied energy (hereinafter also referred to as “energized energy”; hereinafter the same) applied to odd bits and even bits of the thermal head 10. In addition to having the following functions. That is, the first applied energy changing means, when the number of lines in the sub-scanning direction resolution is at least two, sets the size of the perforation located outside the line in the sub-scanning direction to be closer to the center in the line in the sub-scanning direction. The relation data stored in advance in a storage means such as a ROM (corresponding to the number of lines in the sub-scanning direction and the arrangement positions of the odd and even bits) so as to be smaller than that of the perforation located at It has a function of changing the applied energy supplied to each heating element 9 of the thermal head 10 while referring to the relationship with the applied energy).
The second applied energy changing means of the thermal head drive control unit 5 sets, for example, coated paper so that optimum perforation is obtained based on a signal from the coated paper setting key 30 or the non-coated paper setting key 31. Data stored in advance in storage means such as ROM (set corresponding to coated paper and uncoated paper) so that the perforation size is larger than when uncoated paper is set. The applied energy supplied to each heating element 9 of the thermal head 10 is changed with reference to the applied energy).

  The sub-scanning direction feed speed control means included in the microcomputer peripheral circuit 3 and the other control means 8 has a resolution in the sub-scanning direction when executing the special plate making mode by the first control means and the normal plate making mode by the third control means. Based on the signal from the sub-scanning direction resolution setting key 29 as the setting means, or based on the initially set signal, the master conveying means is changed to a feed pitch corresponding to the set resolution feed pitch in the sub-scanning direction. It functions as a second control means for controlling the 19 master feed motors 11.

  The applied energy adjustment means of the thermal head drive controller 5 includes a detection data signal related to the environmental temperature output from the environmental temperature sensor 210, a detection data signal related to the ink temperature output from the ink temperature sensor 211, and a thermal head temperature detection sensor. The detection data signal relating to the thermal head temperature output from 212, the active energy ray curable ink detected or set by the ink type detection sensor 213 or the ink type setting key 32, the ink type detection sensor 213 or the ink type setting key 33 Signal relating to the type of ink such as emulsion ink detected or set, signal relating to the type of printing medium such as coated paper set by the coated paper setting key 30 or non-coated paper set by the non-coated paper setting key 31 Based on the thermal head 10 The applied energy applied to each heating element 9 is set to a predetermined applied energy while referring to a relation data table (relation between combinations of signals and applied energy) stored in advance in storage means such as a ROM. Has a function to adjust.

  The variable printing pressure control means 6 outputs a detection data signal related to the environmental temperature output from the environmental temperature sensor 210, a detection data signal related to the ink temperature output from the ink temperature sensor 211, and a thermal head temperature detection sensor 212. Detection data signal related to thermal head temperature, active energy ray curable ink detected or set by ink type detection sensor 213 or ink type setting key 32, detected or set by ink type detection sensor 213 or ink type setting key 33 Signal relating to the type of ink such as emulsion ink, signal relating to the type of printing medium such as coated paper set by the coated paper setting key 30 or non-coated paper set by the non-coated paper setting key 31, and printing speed setting key 107 based on the signal relating to the printing speed set by The printing pressure by the press roller 23 is changed to a predetermined printing pressure while referring to a relation data table (relation between combinations of signals and printing pressure values) stored in advance in storage means such as a ROM. Thus, it has a function of controlling the printing pressure control motor (14) of the printing pressure variable means 520.

  The mode-by-mode applied energy changing means of the thermal head drive control unit 5 is based on the signal from the character mode setting key 34 or the photo mode setting key 35, and the above-described perforation optimal for the setting with each mode setting key 34, 35. For example, when the photo mode is set, the size of the perforations formed in the film of the master 12 is smaller when the photo mode is set than when the character mode is set. It has a function of changing the applied energy applied to each heating element 9 of the thermal head 10 while referring to relationship data stored in advance in the means (relation with applied energy corresponding to the character mode and photo mode). .

  For example, when the photo mode is set, the mode-specific variable printing pressure control means 7 can obtain the optimum printing pressure for each mode based on the signal from the character mode setting key 34 or the photo mode setting key 35. The relationship data (stored in advance in a storage means such as a ROM so that the printing pressure when pressing the sheet as the printing medium against the printing drum 21 is lower than when the character mode is set. It has a function of controlling the printing pressure control motor (14) of the printing pressure varying means 520 while referring to the relationship between the printing pressure values corresponding to the character mode and the photo mode).

Other notifying control means (not shown) in the control means 8 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. In addition, it has a function of controlling the LCD screen (display / notification means) of the touch panel 98 so as to display / notify it.
The control configuration shown in FIG. 4 is merely an example of the present embodiment. For example, a control configuration in which the microcomputer peripheral circuit 3 is integrated in the thermal head drive control unit 5 may be used. Each means in the drive control unit 5 may be constituted by a microcomputer and a control circuit.

Next, with reference to FIGS. 5A and 5B, 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 this embodiment will be described. FIG. 5A is a schematic perforation pattern formed on the film of the master 12 when the special plate-making mode is executed by the first control unit of the present embodiment (the present invention), and FIG. FIG. 5 is a schematic perforation pattern formed on the film of the master 12 ′ when the normal plate making mode is executed by the third control unit of the embodiment (comparative example), and both are states of the solid portion. The perforation patterns formed on the masters 12 and 12 ′ shown in FIGS. 5 (a) and 5 (b) are all perforated and made for printing on coated paper.
In FIG. 5 and the like, reference numeral 12 ′ is used only when the master 12 ′ obtained by executing the normal plate making mode is described separately from the master 12 obtained by executing the special plate making mode. . When both modes are executed, the masters 12 and 12 'have the same specifications, and the environmental conditions such as temperature and humidity are the same.
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.
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. 5 (a), 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. 5 (a) is that the perforation pattern is arranged like a turtle shell when viewed largely, and is regularly arranged. It is unique. In FIG. 5A, the pitch difference 104 in the sub-scanning direction Y (master transport direction Y) between the odd-numbered bits and the even-numbered bits in the heat generating element 9 is a state in which the heat generating element 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. 5B, 100 ′, 103 ′, and 105 ′ correspond to 100, 103, and 105 in FIG. In FIGS. 5A and 5B, each rectangular frame surrounded by a broken line represents one pixel (the same applies hereinafter).
In the perforated state shown in FIGS. 5 (a) and 5 (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. 5A 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 1.8 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 1.8 μm.

  Next, with reference to FIG. 6, 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 control unit 5 energizes the odd bits and even bits at different timings. As described above, when the thermal head 10 is driven, the DATA signal for printing on the thermal head, the CLK signal for transferring this DATA signal to the driver IC provided in the thermal head 10, and the driver IC Four signals are basically required: a LATCH signal for latching the DATA signal transferred to, and an STB signal for energizing the thermal head 10.

  In FIG. 6, 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 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.

Hereinafter, a perforation pattern that can be formed in the present embodiment will be described with reference to FIG.
The perforation state (perforation pattern) formed in the film of the master 12 shown in FIG. 7 is the perforation pattern when printing on the coated paper by executing the special plate making mode of the present invention as shown in FIG. On the other hand, a perforated state when printing on high-quality uncoated paper by executing the special plate making mode of the present invention is shown. The feature of the perforation 100 shown in FIG. 7 is that it is smaller than the size of the perforation 100 shown in FIG. This is a case of non-coated paper when the ink exuded from the pre-printed master wound around the printing drum 21 shown in FIG. 2 is transferred onto the non-coated paper when printed on the non-coated paper. This is because the ink spreads considerably, so that the spreading is suppressed, excessive ink adhesion to the uncoated paper is suppressed, and the setback characteristic of the stencil printing apparatus is suppressed.
On the contrary, when printing on the coated paper using the master 12 having been made as shown in FIG. 5A, printing was performed on the uncoated paper using the master 12 having been made as shown in FIG. Compared to the case, it can be easily seen that when the ink is transferred onto the coated paper, the spread of the ink is considerably reduced. Therefore, in order to alleviate the phenomenon that the print image density is lowered and the solid image is not filled, it is necessary to form individual perforations 100 as a perforated state.
The thermal perforation pattern shown in FIG. 7 has the same resolution of 600 dpi as shown in FIGS. 5A and 5B except that the plate is made with energy smaller than the energizing energy shown in FIGS. 5A and 5B. 10. Perforated and plate-making under conditions of sub-scan feed resolution (600 dpi) of the plate-making unit 1.

FIG. 8 shows a driving method for melting and perforating the respective heat generating elements 9 of the thermal head 10 with different energization energies when driving the odd-numbered bits and even-numbered bits of the respective heat generating elements 9, that is, the thermal head shown in FIG. By changing the energization energy (for example, energization pulse width) applied to the even-numbered heating element 9 by the first applied energy changing means of the drive control unit 5 to be smaller than that of the odd-numbered bits, the perforation state is also different. 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. The punching pattern shown in FIG. 8 is punched and made under the same conditions as those shown in FIGS. 5A and 5B except that the thermal head 10 has the same resolution of 600 dpi and the sub-scan feed resolution (600 dpi) of the plate making unit 1. It is a thing.
The adjustment / change of the applied energy (perforation energy) can be performed by changing the value of the current flowing through each heating element 9 of the thermal head 10 or the heating element 9 according to the image signal as described in Japanese Patent No. 2756219. Although it may be performed by changing the voltage value to be applied, in the present embodiment, 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. Is.

FIG. 9 shows the resolution setting in the sub-scanning direction that can be set to less than the resolution pitch (600 dpi) of the thermal head 10 as the resolution feed pitch in the sub-scanning direction Y when melting and perforating with each heating element 9 of the thermal head 10. As a means, the sub-scanning direction resolution key 31 is set to 800 dpi, and the control is performed by the microcomputer peripheral circuit 3 as the second control means and the control by the sub-scanning direction feed speed control means of the other control means 8. The perforation state at the time of making a plate is shown. The perforation pattern shown in the figure is perforated and made with the thermal head 10 having the same resolution of 600 dpi as shown in FIG. 8 except as described above.
According to the example shown in FIG. 9, as can be seen from FIG. 9, the resolution in the sub-scanning direction Y is improved, and the printed image is also good. According to the example shown in FIG. 9, the effect that the printing state at the time of the finer line becomes smoother than the perforation pattern shown in FIG. 8 can be obtained.

In FIG. 10B, the first applied energy changing means of the thermal head drive control unit 5 varies the applied energy applied to the odd bits and the even bits of the thermal head 10, and the sub-scanning direction resolution is changed. When the number of lines is at least 2 (six lines in the figure), the size of the perforation 106 located outside the line in the sub-scanning direction Y is set to the size of the perforation 106 located near the center of the line in the sub-scanning direction Y. Relational data stored in advance in storage means such as ROM (relationship between the number of lines in the sub-scanning direction and the applied energy supplied corresponding to the positions of the odd and even bits to be smaller than that) ), Etc., the punching and plate making when the energizing energy supplied to each heating element 9 of the thermal head 10 is changed are made. It shows the state.
Here, the number of lines in the sub-scanning direction resolution is represented by the line 101 corresponding to the odd bits in the figure, but strictly speaking, melt drilling is performed corresponding to the odd bits in the heating element 9. The number of lines in the sub-scanning direction Y connecting the perforations 100 and the perforations 106 that are fused and perforated with a pitch difference 104 in the sub-scanning direction Y corresponding to even bits, that is, the main scanning direction S of the thermal head 10. Means a line in which the heating elements 9 arranged in a row are driven to generate heat at one time (the resolution in the other sub-scanning direction indicates a pitch of 103).
FIG. 10A shows the punching state when the number of lines in the sub-scanning direction resolution is two lines, and FIG. 10B shows the punching state when the number of lines in the sub-scanning direction resolution is six lines and is somewhat thick. Show. Thus, by combination with the sub-scanning direction resolution setting means, the perforations 106 located outside the line in the sub-scanning direction Y, in other words, perforations 106 located above and below in FIGS. 10A and 10B, respectively. The outer perforation line in the sub-scanning direction Y is formed by perforating and making a plate while changing the energization energy so that the size of the perforation 106 is smaller than that of the perforation 106 located near the center of the line in the sub-scanning direction Y. It is possible to make the image closer to a straight line, that is, it is possible to reduce the image level difference in the outer perforation line portion in the sub-scanning direction Y and flatten the image, so that it is possible to obtain better print image quality.

Next, the operation of this embodiment executed under the instruction of the CPU of the microcomputer peripheral circuit 3 of the control unit 2 shown in FIG. 4 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.
First, in step S1 shown in FIG. 11, 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 it is determined whether or not the sub-scanning direction resolution setting key 29 is ON. If the sub-scanning direction resolution setting key 29 is not turned on, an initial 600 dpi corresponding to the normal plate making mode is set as a sub-scanning direction resolution (hereinafter also referred to as “sub-scanning resolution”) feed pitch in step S3. When the sub-scanning direction resolution setting key 29 is turned on, in step S4, the setting value of 800 dpi is read as the sub-scanning resolution, and 800 dpi is set as the sub-scanning resolution feed pitch.
In the plate making based on the sub-scanning resolution set as described above, the microcomputer peripheral circuit 3 constituting the second control means is based on the signal from the sub-scanning direction resolution setting key 29 or the initially set signal. And the sub-scanning direction feed speed control means of the control means 8 controls the master feed motor 11 of the master transport means 19 so as to change it to a feed pitch corresponding to the set resolution feed pitch in the sub-scanning direction, and also sets it. This is done by controlling the document feed motor of the output unit 28 so as to change the document feed pitch to the resolution feed pitch in the sub-scanning direction. Note that when reading a document, the document may be read once and image processing such as interpolation processing corresponding to the resolution in the sub-scanning direction may be performed later.

Next, the process proceeds to step S5, and it is determined whether the plate-making condition is the character mode or the photo mode. Here, when the character mode is set by touching the character mode setting key 34 or the photo mode is set by touching the photo mode setting key 35, the character mode setting key is changed by the mode-specific applied energy changing means of the thermal head drive controller 5. For example, when the photo mode is set so that the optimum perforation size can be obtained based on the signal from the photo mode setting key 35 or the photo mode setting key 35, the master 12 is set more than when the character mode is set. Control and setting are performed so that the size of the perforations formed in the film is reduced (steps S6 and S7).
In this embodiment, only the character mode and the photo mode are described. However, if there are a character / photo mode when the characters and the photo are mixed, a mode such as the pencil mode, etc. Plate making or printing is performed under conditions suitable for the mode.

  In step S8, the coated paper setting key 30 or the uncoated paper setting key of the coated paper / non-coated paper setting means (coated paper / non-coated paper separate plate making / printing mode selection means) described above with respect to the paper to be used. 31 is set by touching. When the uncoated paper is set and recognized by the uncoated paper setting key 31, the normal plate making mode is set as the setting of the plate making method corresponding to the uncoated paper, that is, the initial setting (initial) (step S9). On the other hand, when the coated paper is set and recognized by the coated paper setting key 30, a special plate-making mode specific to the present invention is set as setting of the plate-making method corresponding to the coated paper, that is, initial setting (initial) (step S10). ).

The modes related to the plate making method selected as described above are roughly divided into two types, and the plate making settings are classified as follows. That is,
Normal plate-making mode: This is a mode in which uncoated paper is set, and is a mode in which punching and plate-making operations are executed by the third platen by the normal plate-making (conventional plate-making) method.
Special plate making mode: in the case of coated paper setting, the perforation state in the present invention, that is, the perforation is performed in the main scanning direction by the heat generation driving of the odd and even bits of each heating element 9 in the thermal head 10 by the first control means. In this mode, a punching state is obtained in which each hole is formed on different rows of S and the holes are not adjacent to each other on the same row in the main scanning direction S by heat generation driving of adjacent odd and even bits. is there. These two types of plate making mode settings are made by the plate making method selection means of the thermal head drive controller 5 shown in FIG.
When executing the special plate-making mode set when it is recognized as coated paper, the resolution pitch of the thermal head 10 is used as the resolution feed pitch in the sub-scanning direction as in the case of executing the normal plate-making mode set for non-coated paper. It goes without saying that plate making is performed at a sub-scanning resolution of 800 dpi set and recognized by the sub-scanning direction resolution setting key 29 as the above-described sub-scanning direction resolution setting means. As a matter of course, when setting is not performed with the sub-scanning direction resolution setting key 29 when setting the plate making method of uncoated paper or coated paper, the resolution of the thermal head 10 is set as the sub-scanning resolution. (For example, 600 dpi) (see FIGS. 5A, 5B, and 7).

Next, the process proceeds to step S11, and when the normal plate making mode or the special plate making mode which is the set plate making method is executed, the plate making is performed under the optimum conditions from the environment and the plate making printing conditions. That is, when coated paper is set, the second applied energy changing means of the thermal head drive control unit 5 controls / sets the perforation size to be larger than when uncoated paper is set. Is done.
At this time, the detection data signal related to the environmental temperature output from the environmental temperature sensor 210, the detection data signal related to the ink temperature output from the ink temperature sensor 211, and the thermal head temperature output from the thermal head temperature detection sensor 212. Detection data signal, active energy ray curable ink detected or set by ink type detection sensor 213 or ink type setting key 32, ink such as emulsion ink detected or set by ink type detection sensor 213 or ink type setting key 33 Based on the signal relating to the type, the signal relating to the type of the printing medium such as the coated paper set by the coated paper setting key 30 or the non-coated paper set by the non-coated paper setting key 31, the thermal head drive control unit The applied energy adjusting means 5 is thermal. The applied energy to be applied to the individual heating elements 9 of the head 10 is adjusted to a predetermined applied energy.

In the present embodiment, the case where all the above-described parameters for adjusting the applied energy (environment temperature, ink temperature, thermal head temperature, ink type, type of printing medium) are used as the environment and plate-making printing conditions is exemplified. However, the present invention is not limited to this, and at least one or more parameters for adjusting applied energy may be used in accordance with the application, necessity, or cost. In addition, the energization energy to the individual heating elements 9 of the thermal head 10 changes in order to obtain a predetermined size of perforation depending on the type of master to be used (for example, the thickness and material of the film). It may be used as
Based on the above operation contents, it is determined whether or not the plate making is completed. If the plate making is not completed, the process returns to step S11, and the CPU determines that the plate making is completed by a predetermined number of steps of the master feed motor 11. The plate making is completed (step S12).

  Next, a case where a printing operation is executed in step S1 will be described. As described above, after setting and recognizing non-coated paper or coated paper with the coated paper setting key 30 or the non-coated paper setting key 31 of the coated paper / non-coated paper setting means, in step S13, uncoated paper or coated paper is set. Printing is performed under a printing pressure suitable for paper. The conditions at this time vary depending on the process of the stencil printing apparatus, the type of master to be used, the type of ink (emulsion ink or active energy ray-curable ink), the printing speed, etc. When the printing pressure condition of the coated paper is set higher than the printing pressure condition of the coat, and the emphasis is on preventing the occurrence of printing wrinkles, which is the object of the present invention, the coated paper pressure condition is reversed rather than the uncoated printing pressure condition. Lower the printing pressure condition.

During printing, when the photo mode is set with the photo mode setting key 35, the press for pressing the paper against the printing drum 21 by the mode-specific printing pressure variable control means 7 rather than when the character mode is set. It is controlled and set so that the printing pressure by the roller 23 is lowered.
As described in step S6 and step S7 during execution of the plate-making operation, the optimum perforation size corresponding to each mode is set, but as an example here, when the photo mode is set, Control and setting are performed so that the size of perforations formed in the film of the master 12 is smaller than when the character mode is set. This is because when the photographic mode is set, it is necessary to ensure that the print image dots are independent in order to improve the reproducibility of the photographic image. Furthermore, in the case of non-coated paper, the printed dots are likely to bleed and are hardly noticeable in the first place. However, in the case of coated paper, there is a problem that a black dot image is generated when the printed dots are connected. This defect appears remarkably in the active energy ray curable ink used in this embodiment.
In printing, a detection data signal related to the environmental temperature output from the environmental temperature sensor 210, a detection data signal related to the ink temperature output from the ink temperature sensor 211, and a thermal data output from the thermal head temperature detection sensor 212. Detection data signal related to head temperature, active energy ray curable ink detected or set by ink type detection sensor 213 or ink type setting key 32, emulsion detected or set by ink type detection sensor 213 or ink type setting key 33 A signal relating to the type of ink such as ink, a signal relating to the type of printing medium such as coated paper set by the coated paper setting key 30 or non-coated paper set by the non-coated paper setting key 31, and a printing speed setting key 107 The signal related to the printing speed set by Zui, the indicia pressure variable control means 6, the printing pressure by the press roller 23 is controlled and set to a predetermined printing pressure.

  In the present embodiment, the case where all the parameters for adjusting the printing pressure (environment temperature, ink temperature, thermal head temperature, ink type, type of printing medium, printing speed) are used as the environment and printing conditions is illustrated. However, the present invention is not limited to this, and at least one printing pressure adjustment parameter may be used depending on the application, necessity, or cost.

  Next, with reference to FIG. 12, a description will be given of a first embodiment relating to plate making / printing executed in the special plate making mode by the first and second control means and in the conventional normal plate making mode by the third control means. In this embodiment, the punched state (perforated pattern) obtained by executing the conventional normal plate making mode, the printing state when printing on the coated paper using the master made in the punched state, and the present embodiment The perforated state obtained by executing the special plate-making mode of the present invention and the printed state when the perforated state is made on the coated paper using the master plate-made, and comparing the active energy ray-curable ink and the coat A print wrinkle caused by floating of a used master that occurs during printing in combination with paper will be described.

The photographs shown on the left side, center, and right side of FIG. 12 were each printed on coated paper using a perforated state (perforated pattern) when a solid image of 33 × 33 mm was perforated and made, and the pre-made master. The printing state is shown.
The photograph shown on the left side of the figure is printed on the coated paper using the perforated state (perforated pattern) obtained by the combination of coated paper and active energy ray-curable ink in the conventional normal plate making mode and the pre-made master. 1 shows a printed matter that has been completely fixed using the active energy ray curable fixing device 201 shown in FIG.

The photograph shown in the center of the figure is the special plate-making mode of the present embodiment (the present invention), and the resolution in the sub-scanning direction (sub-scanning resolution feed pitch) in the stencil printing apparatus is the same as the resolution pitch of the thermal head 10. In the case of the normal pitch (600 dpi), the perforated state (perforated pattern) obtained by combining the coated paper and the active energy ray curable ink and the printed material printed on the coated paper using the pre-printed master Similarly, a printed matter that is completely fixed using the active energy ray curing fixing device 201 is shown.
The photograph shown on the right side of the figure is the special plate-making mode of the present embodiment (the present invention), and the sub-scanning direction resolution (sub-scanning direction) in the stencil printing apparatus by the sub-scanning direction resolution setting means of the present embodiment (the present invention). The perforation state (perforation pattern) obtained by the combination of the coated paper and the active energy ray curable ink when the scanning resolution feed pitch) is set to be less than the resolution pitch of the thermal head 10 (fine pitch) (800 dpi), and The printed material printed on the coated paper using the pre-printed master, which is also completely fixed using the active energy ray curable fixing device 201, is shown. 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. In the special plate making mode of the present embodiment (the present invention), precise control with fine grain, that is, first and second applied energy changing means, applied energy adjusting means, and applied mode, in the thermal head drive controller 5 shown in FIG. The applied energy changing means, the printing pressure variable control means 6 and the mode-specific printing pressure variable control means 7 are not controlled, and even in the conventional normal plate making mode, the applied energy adjusting means, the mode-specific applied energy changing means, and the printing pressure variable. The control by the control means 6 and the mode-specific variable printing pressure control means 7 was not carried out, but was carried out under relatively simple plate making and printing conditions.
Environmental conditions: Temperature 24 ° C, humidity 38% RH
Thermal head resolution: 600 dpi
Sub-scanning direction resolution (sub-scanning resolution feed pitch) ... 600 dpi (normal pitch), 800 dpi (high density pitch)
Image pattern (perforation pattern): Solid Master used: “Type I master” manufactured by Ricoh Co., Ltd. Thermoplastic resin film, at least one porous resin film and a porous support described in JP-A-10-147075 And a master having
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. 12 printed under the above conditions shows the above-mentioned coated paper using a perforated master made in the conventional normal plate-making mode in combination with the above-mentioned coated paper and the above active energy ray-curable ink. Since the printed matter is a printed matter that has been completely fixed using the active energy ray curing fixing device 201, a white streak-like image defect has occurred in the horizontal direction of the solid image in question. On the other hand, the central part and the right side of FIG. 12 show the perforated plate making obtained by the 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). This is a printed matter printed on the above coated paper using a completed master, which is also a completely fixed printed matter using the active energy ray curable fixing device 201. It is seen that no image is obtained.

  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, to the rear side of the discharge 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. . Therefore, as shown in FIG. 13, compared with the master 12 'that has been made by the conventional normal plate making mode, the plate making obtained by the special plate making mode of the present embodiment (the present invention) 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. 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, in this embodiment (the present invention), even if the ink used in the stencil printing apparatus is an emulsion ink or an active energy ray curable ink for stencil printing, it is further uncoated paper (high quality paper). Paper, etc.) or coated paper, it is possible to realize and provide a stencil printing apparatus that does not cause printing wrinkles and master deviation by the master and obtains an optimum print image quality, and also performs sub-scanning. By setting the resolution feed pitch in the sub-scanning direction in the stencil printing apparatus to be less than the resolution pitch of the thermal head by the direction resolution setting means, it becomes possible to obtain a better print image quality particularly with respect to fine lines, Further, the effects described in the above-described effect column 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.
The coated paper / non-coated paper setting means (coated paper / non-coated paper separate plate making / printing mode selection means) is not limited to this, and for example, by detecting a difference in the amount of reflected light and comparing it with a predetermined threshold, It may be a detecting means for detecting the coated paper.

  In general, the spread of printed dots when emulsion ink is printed on paper is larger than that of active energy ray curable ink, so the energy applied to the thermal head is reduced and the perforated state on the master is reduced. By reducing the size, the spreading of the printed dots is suppressed. However, although it is roughly divided into emulsion ink and active energy ray curable ink, depending on the formulation of the ink, there may be a reversal. I do not care. Emulsion inks and active energy ray-curable inks can handle several types of ink, etc., and set and identify a little more detailed like each color ink, etc., and create a plate-making image suitable for each ink with finer control It doesn't matter.

In general, coated paper has a smaller spread of printed dots on the paper than uncoated paper. Therefore, the applied energy to the thermal head is increased to increase the perforated state of the master, which is suitable as the printed dots. Try to get things. However, there are various types of uncoated paper and coated paper. For example, in coated paper, the paper called gloss paper has a much higher smoothness on the paper surface, and the paper that does not show the spread of printing dots or the paper called matte paper has a lower paper surface smoothness than the gloss paper. Some have some degree of dot spread. In this way, each sheet may be set in detail, and a plate-making image suitable for each sheet may be created with finer control.
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 an embodiment 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 shown to FIG. 1 and FIG. (A) is a plan view for explaining the perforated state of a master that has been made in a special plate making mode corresponding to the coated paper of the present embodiment (the present invention), and (b) corresponds to the coated paper. It is a top view explaining the punching state of the master after completion of the plate-making obtained by the conventional normal plate-making mode. It is a timing chart of each signal transmitted to the thermal head of this embodiment. It is a top view explaining the punching state of the master made by plate making obtained by the special plate making mode corresponding to the uncoated paper of this embodiment. It is a top view explaining the piercing | piercing state of the master made by platemaking obtained when energizing energy was varied regarding the piercing | piercing pattern which can be formed by the special plate-making mode of this embodiment. Regarding the perforation pattern that can be formed by the special plate-making mode of the present embodiment, the energization energy is made different and the plate-printed pattern obtained when the sub-scanning direction resolution feed pitch is set to 800 dpi higher than the resolution pitch 600 dpi of the thermal head. It is a top view explaining the drilling state of a master. FIG. 10A shows a punched state in the case where the number of lines in the sub-scanning direction resolution of the master that has been made by the special plate-making mode of this embodiment is 2 lines, and FIG. 10B shows the same in the sub-scanning direction. It is a top view which shows each perforation state in case the number of lines of resolution is 6 lines. It is a flowchart showing the plate making and printing operation of the principal part of this embodiment. A photograph showing Example 1, which is shown 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 this in the center portion. What is shown is the master perforation state obtained when the sub-scanning resolution feed pitch is set to be the same as the resolution pitch of the thermal head in the special plate making mode of the present embodiment (the present invention), and this is used. The printing state when printing on coated paper is shown on the right side when the sub-scanning resolution feed pitch is set to less than the resolution pitch of the thermal head in the special plate making mode of the present embodiment (the present invention). It is a photograph which respectively shows the punching state of the obtained master, and the printing state when printing on 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. It is a figure explaining the area of the remaining width (non-image part) between the adjacent perforations in the main scanning direction when a master made by plate making obtained by the special plate making mode of the present embodiment (the present invention) is bent. .

Explanation of symbols

1 Plate making section (plate making equipment)
2 Control section 3 Microcomputer peripheral circuit (constituting first, second and third control means)
4 Image processing section 5 Thermal head drive control section (constituting first and third control means)
6 Printing pressure variable control means 7 Mode-specific printing pressure variable control means 8 Other control means (constitutes sub-scanning direction feed speed control means and second control means)
9 Heating element (heating element)
10 Thermal head (plate making means)
11 Master feed motor (master transport drive means)
12 Master 14 Platen roller (Master conveying means)
19 Master conveying means 21 Printing drum 23 Press roller (pressing means)
28 Other output section 29 Sub-scanning direction resolution setting key (Sub-scanning direction resolution setting means)
30 Coated paper setting key (Coated paper / non-coated paper setting means, printing medium type setting means)
31 Uncoated paper setting key (coated paper / uncoated paper setting means, printing medium type setting means)
32 Ink type setting key (Ink type setting means)
33 Ink type setting key (Ink type setting means)
34 Text mode setting key (text / photo mode setting)
35 Photo mode setting key (text / photo mode setting)
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 107 Printing speed setting key (printing speed setting means)
DESCRIPTION OF SYMBOLS 200 Stencil printing apparatus main body 201 Active energy ray hardening fixing device 202 Paper feed part 203 Paper feed stand 204 Paper discharge stand 213 Ink type detection sensor (ink type detection means)
S Main scanning direction Y Sub-scanning direction / Master transport direction

Claims (12)

A thermal head having a large number of heating elements arranged in the main scanning direction is directly brought into contact with the thermoplastic resin film side of the master having the thermoplastic resin film, and the sub scanning direction is orthogonal to the main scanning direction. While the master is moved by the master conveying means, the thermoplastic resin film is melted and perforated by position-selective heat generation driving of the respective heating elements according to the image signal to obtain a perforation pattern according to the image signal, The preprinted master on which the perforated pattern is formed is wound around the outer peripheral surface of the printing drum, ink is supplied from the inner peripheral side of the printing drum, and the image signal is generated by the ink that has oozed through the perforated pattern. A corresponding ink image is formed on the printing medium, and an active energy ray-curable ink is used as the ink. Printing is possible to the non-coated paper and coated paper, and, in the stencil printing apparatus capable of completely fixing,
Perforations formed in the thermoplastic resin film are formed on different rows in the main scanning direction 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. And the master is made so that the perforations formed in the thermoplastic resin film are not adjacent to each other in the main scanning direction by the heat generation driving of the adjacent odd and even bits adjacent to each other. First control means for executing a special plate-making mode;
Master transport driving means for driving the master transport means so as to move the master at a predetermined feed pitch;
Sub-scanning direction resolution setting means capable of setting the resolution feed pitch in the sub-scanning direction to be less than the resolution pitch in the main scanning direction of the thermal head;
When executing the special plate making mode, the master transport driving unit is controlled to change to a feed pitch corresponding to the set resolution feed pitch in the sub-scanning direction based on a signal from the sub-scanning direction resolution setting unit. Second control means to:
A stencil printing apparatus comprising: In the stencil printing apparatus according to claim 1,
A stencil printing apparatus, wherein the thermoplastic resin film is perforated independently of each other by the thermal head. In the stencil printing apparatus according to claim 1 or 2,
A stencil printing apparatus characterized in that, as a perforated state of the thermoplastic resin film by the thermal head, a remaining width dimension between adjacent perforations of the thermoplastic resin film is wider than a thickness of the thermoplastic resin film . In the stencil printing apparatus according to any one of claims 1 to 3,
A stencil printing apparatus comprising first applied energy changing means for making different applied energy to be applied to the odd bits and the even bits. In the stencil printing apparatus according to claim 4,
When the number of lines in the sub-scanning direction resolution is at least two lines, the first applied energy changing means determines the size of the perforation located outside the line in the sub-scanning direction as the center portion in the line in the sub-scanning direction. A stencil printing apparatus, wherein the applied energy is changed so as to be smaller than that of a perforation located closer to the surface. In the stencil printing apparatus according to any one of claims 1 to 5,
Plate-making / printing mode setting means capable of setting a plate-making / printing mode for executing plate-making and printing operations respectively corresponding to the coated paper and the non-coated paper;
Based on the signal from the coated paper / non-coated paper separate plate making / printing mode setting means, the applied energy is changed so as to obtain the optimum perforation size for the setting by the setting means. Applied energy changing means;
A stencil printing apparatus comprising: In the stencil printing apparatus according to any one of claims 1 to 6,
Environmental temperature detection means for detecting environmental temperature, thermal head temperature detection means for detecting the temperature of the thermal head, ink temperature detection means for detecting ink temperature, ink type detection means for detecting ink type, ink for setting ink type At least one of a type setting means, a printing medium type detecting means for detecting the type of printing medium, and a printing medium type setting means for setting the type of printing medium;
Applied energy adjusting means for adjusting applied energy applied to each heating element of the thermal head to a predetermined energy based on a signal from the at least one means;
A stencil printing apparatus comprising: In the stencil printing apparatus according to any one of claims 1 to 7,
A printing pressure variable means for changing a printing pressure when the printing medium is pressed against the printing drum;
Environmental temperature detection means for detecting environmental temperature, thermal head temperature detection means for detecting the temperature of the thermal head, ink temperature detection means for detecting ink temperature, ink type detection means for detecting ink type, ink for setting ink type At least one of a type setting means, a printing medium type detecting means for detecting the type of the printing medium, a printing medium type setting means for setting the type of the printing medium, and a printing speed setting means for setting the printing speed When,
Printing pressure variable control means for controlling the printing pressure variable means so that the printing pressure becomes a predetermined printing pressure based on a signal from the at least one means;
A stencil printing apparatus comprising: In the stencil printing apparatus according to any one of claims 1 to 8,
Character / photo mode setting means for setting a character mode for performing a plate making operation corresponding to a character image or the like and a photo mode for performing a plate making operation corresponding to a photo image or the like;
Based on the signal from the character / photo mode setting means, the applied energy changing means for each mode for changing the applied energy applied to each heating element of the thermal head so as to obtain the optimum perforation size for each mode. When,
A stencil printing apparatus comprising: The stencil printing apparatus according to any one of claims 1 to 9,
A printing pressure variable means for changing a printing pressure when the printing medium is pressed against the printing drum;
Character / photo mode setting means for setting a character mode for performing a printing operation corresponding to a character image or the like and a photo mode for performing a printing operation corresponding to a photo image or the like;
Based on a signal from the character / photo mode setting means, a mode-specific printing pressure variable control means for controlling the printing pressure variable means so as to obtain the optimum printing pressure for each mode;
A stencil printing apparatus comprising: In the stencil printing apparatus according to any one of claims 1 to 10,
The stencil printing apparatus, wherein the master has the thermoplastic resin film and at least one porous resin film. In the stencil printing apparatus according to any one of claims 1 to 11,
Third control means for executing a normal plate making mode for making a master so that perforations formed in the thermoplastic resin film are formed on the same line in the main scanning direction by the heat generation driving of each of the heating elements is provided. And
A stencil printing apparatus characterized in that both the special plate-making mode by the first control means and the normal plate-making mode by the third control means can be executed.

Images