JP2000238230A - Plate-making apparatus and plate-making printing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form an optimum print image being excellent in image size reproducibility due to suppression of shrinkage of a master and having little nonuniformity in the density of the print image and others and also to reduce the disadvantage of offset peculiar to a plate-making printing apparatus, in regard to any original image. SOLUTION: A minute heating body group 25 wherein a plurality of minute heating bodies 20 driven to heat simultaneously in correspondence to one pixel of image data are disposed in a plurality in the main scanning direction S and the sub-scanning direction F respectively is provided, and the minute heating body groups 25 are arranged in a plurality in the main scanning direction S.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate making apparatus and a plate making and printing apparatus. The present invention relates to a plate-making apparatus and a plate-making printing apparatus which are obtained in plurality.

[0002]

2. Description of the Related Art As a simpler printing method, a digital thermosensitive plate making printing apparatus has been known. In this device,
A thermal head, in which a plurality of minute heating elements, also called heating elements or heating elements, are arranged in the main scanning direction, is connected via a heat-sensitive master having a thermoplastic resin film (hereinafter simply referred to as “master”). The master is conveyed in the sub-scanning direction (hereinafter, sometimes referred to as “master conveying direction”) orthogonal to the main scanning direction by the platen roller while applying pressure to the heating element of the thermal head by applying pressure to the heating element of the thermal head to generate heat. In this way, after heating and melting / perforating plate making based on the image information, the master is automatically conveyed and automatically wound around the outer peripheral surface of the porous cylindrical plate cylinder, and a press roller is applied to the master on the plate cylinder. A printing image is formed by continuously pressing the printing paper with a pressing means such as the above and passing the ink from the perforated portion to transfer the ink to the printing paper.

[0003] The plate-making printing apparatus is provided with a plate-making apparatus for performing the perforated plate-making as described above. Until a time ago, the external form of the plate-making apparatus described above and the thermal head itself mounted on the plate-making printing apparatus were relatively small. The width of the common electrode included in the thermal head is so large that it does not greatly affect the heat generation efficiency of the thermal head. However, in recent years, the thermal head itself has been miniaturized, and the power loss at the common electrode cannot be ignored. In the conventional thermal head,
The punching energy is applied to one of the heating elements driven to generate heat corresponding to one pixel of the image data to perforate the thermoplastic resin film portion of the master to obtain a printed image.

When a print image is obtained by using a plate-making printing apparatus, it is a major premise that a better print image is provided to a user. An apparatus that can further reduce ink stains caused by transfer of ink on the surface of the printing paper of the previous printed matter to the back surface of the printing paper instead of the front surface of the printing paper coming in) is further desired in the future. In recent years, in addition to the improvement of print image quality mentioned above, it has become increasingly necessary to create cheaper products and environmentally friendly products when considered on a global scale. It has become essential to increase the production efficiency of the components constituting the plate making printing apparatus itself and to reduce the amount of component materials and the like. For this reason, it is necessary to reduce the size of components, and is there a need to establish technology to reduce the size of thermal printers used in plate making printing machines and plate making machines? There must be.

[0005]

However, the external shape of the thermal head itself mounted on a plate-making apparatus or a plate-making printing apparatus of a long time ago is relatively large, and the common electrode width of the thermal head is also large in the heat generation efficiency of the thermal head. Since it has been used to the extent that it does not have an effect, the thermal drive of the thermal head has been taken into account using the thermal history control etc., which is a well-known technology, without considering the energy loss at the common electrode. , A punching energy was applied to the thermoplastic resin film portion of the master to obtain a printed image.

On the other hand, in recent years, downsizing of thermal heads has been promoted for the above-mentioned reasons and the like. When the printing rate in the block is high, there is a problem that a considerable difference in print image density occurs. The printing rate means the ratio of the number of currents actually supplied to the heating elements to the total number of heating elements belonging to the simultaneous power supply block. One reason for the difference in print image density is due to the phenomenon of energy loss caused by power loss due to the voltage drop caused by the electric resistance of the common electrode in the thin film substrate provided in the thermal head. It is. When making a perforated plate on the master, the heat generated by the plurality of heating elements of the thermal head is used to heat and melt the thermoplastic resin film portion of the master. Therefore, the same perforated state cannot be obtained because the perforated state is different, and as a result, a printed image density unevenness occurs because the perforated state appears as a print image density difference, thereby resulting in poor quality of the printed image. There was a problem that it became a thing.

Further, hitherto, when a thermoplastic resin film portion of a master is heat-melted with heat generated by a plurality of heating elements arranged in a line in a main scanning direction in a thermal head to perform perforation, image data of the master is not obtained. Since perforation is performed in units of one heating element driven to generate heat corresponding to one pixel, the perforation state is a main scanning resolution dot pitch in the main scanning direction and a sub scanning resolution dot pitch in the sub scanning direction (master feed pitch). Or a sub-scanning feed pitch), so that the required print image density is secured while the offset is suppressed, and the print image quality is improved. It was difficult only by controlling the state.

Further, when a conventional thermal head prints an original image having a particularly high printing rate, the master contracts (especially in the sub-scanning direction caused by slippage caused by insufficient friction between the platen roller and the master). This causes a reduction in the reproducibility of the image dimensions caused by the (shrinkage of the master). As a countermeasure against the master shrinkage, the position of the nip portion where the platen roller and the thermal head are in close contact with each other is shifted to the downstream side in the sub-scanning direction, in other words, the position of the heating element of the thermal head is changed to the master transport outlet. At present, the effect is reduced due to the influence of the components of the unit making up the plate making unit, the assembling accuracy thereof, the variation in the position of the heating element of the thermal head, and the like.

There are several measures to reduce the power loss at the common electrode described above.
Generally, the thickness of the heating element is reduced to increase the resistance, and in the case of such a measure, there is a problem that the life of the heating element in the thermal head is shortened. .

Therefore, the present invention has been made in view of the above-mentioned circumstances, and is not limited to any original image to be made when a master is made by using a thermal head in a plate-making apparatus or a plate-making printing apparatus. In addition, the power loss at the common electrode etc. can be suppressed, and the uniform and fine perforations independent of each other as the perforated state of the master that has been perforated / plated correspond to one pixel of image data. It can be obtained at any location on the heating element of the thermal head driven to generate heat, and forms a perforated image suitable for the resolution in the main scanning direction and the sub-scanning direction. By suppressing the shrinkage, the image size reproducibility is good, and it is possible to form an optimal print image with less print image density unevenness,
At the same time, by reducing excessive transfer of ink used in the plate-making printing device to the printing paper, the problem of set-off that is peculiar to the plate-making printing device can be considerably reduced, and a thermal head mounted on the plate-making device and the plate-making printing device. With the downsizing of the head, high efficiency in production has been achieved, it has become inexpensive for the user and can be reflected in the price of the product, and the amount of materials used can be reduced with the downsizing of the thermal head, It is another object of the present invention to provide a plate-making apparatus and a plate-making printing apparatus which can provide a more environmentally friendly product and can obtain many of these advantages.

[0011]

Means for Solving the Problems In order to solve the above-mentioned problems, the invention described in each claim has the following configuration. According to the first aspect of the present invention, a thermal head having a plurality of heating elements is brought into contact with a thermosensitive master having a thermoplastic resin film in the main scanning direction, and the thermosensitive master is brought into contact with the thermal head in the main scanning direction. In a plate making apparatus for making a plate while relatively moving in a sub-scanning direction perpendicular to the sub-scanning direction, the miniaturized heating elements which are simultaneously driven to generate heat corresponding to one pixel of image data are respectively moved in the main scanning direction and the sub-scanning direction. It has a plurality of miniaturized heating elements arranged,
A plurality of the miniaturized heating elements are arranged in the main scanning direction.

According to a second aspect of the present invention, in the plate making apparatus according to the first aspect, an outermost one of each of the miniaturized heating elements located at an outermost end in the main scanning direction among the miniaturized heating elements. The distance between the ends is set to be equal to or less than a distance obtained by multiplying the resolution pitch of the adjacent miniaturized heating elements in the main scanning direction by 0.9.

According to the third aspect of the present invention, a thermal head having a plurality of heating elements is brought into contact in the main scanning direction with a thermosensitive master having a thermoplastic resin film, and the thermosensitive master is contacted with the thermal head. In a plate making apparatus for making a plate while relatively moving in a sub-scanning direction orthogonal to a main scanning direction, a plurality of miniaturized heating elements which are simultaneously driven to generate heat corresponding to one pixel of image data are arranged in the main scanning direction. And a plurality of the miniaturized heating elements arranged in the main scanning direction.

According to a fourth aspect of the present invention, in the plate making apparatus according to the third aspect, the outermost end of each of the miniaturized heating elements located at the outermost end in the main scanning direction of the group of miniaturized heating elements. The distance between the ends is set to be equal to or less than the distance obtained by multiplying the resolution pitch of the adjacent miniaturized heating elements in the main scanning direction by 0.9.

According to a fifth aspect of the present invention, in the plate-making apparatus according to the first or second aspect, each of the miniaturized heating elements located at the outermost end in the sub-scanning direction among the miniaturized heating elements is selected. The distance between outermost ends is set to be equal to or less than a value obtained by multiplying the resolution pitch of the plate making apparatus in the sub-scanning direction by 0.9.

The invention according to claim 6 is the invention according to claims 1 to 5
The plate making apparatus according to any one of the above, further comprising: a thermal head temperature detecting means for detecting a temperature of the thermal head, wherein the thermal head temperature detecting means detects the temperature of the thermal head according to the temperature of the thermal head. A thermal head temperature-dependent drilling energy adjusting means for adjusting the drilling energy supplied to the miniaturized heating element to a predetermined drilling energy is provided. According to a seventh aspect of the present invention, in the plate making apparatus according to any one of the first to sixth aspects, the plate making apparatus further comprises a current supply number counting means for counting the number of currents to be supplied to the respective miniaturized heating elements. In accordance with the number of currents counted by the number of currents counted by the number-of-currents counting means, there is provided a perforation rate-specific perforation energy adjusting means for adjusting perforation energy supplied to the miniaturized heating element of the thermal head to predetermined perforation energy. Features. According to the seventh aspect of the present invention, the number of energization counting means is set to a plurality of the miniaturized heating element groups at the same time in that the group of miniaturized heating elements is divided into several blocks and energized simultaneously for each block. For each block for energizing, count the number of energizations actually energized to each of the miniaturized heating elements, the energization rate-dependent perforation energy adjustment means according to the energization number counted by the energization number counting means, A configuration is adopted in which perforation energy supplied to the miniaturized heating element of the thermal head is adjusted to a predetermined perforation energy for each block for simultaneously energizing a plurality of the miniaturized heating elements. Is preferred.

[0017] The invention according to claim 8 is the invention according to claims 1 to 7.
A plate cylinder for winding the master made by the plate making device around the outer peripheral surface of the plate cylinder, and ink supply means for supplying ink to the master on the plate cylinder. And a printing machine for printing on at least one side of the printing paper by pressing the printing paper against the master on the plate cylinder.

According to a ninth aspect of the present invention, in the stencil printing machine according to the eighth aspect, there is provided an ink temperature detecting means for detecting the temperature of the ink, and the ink temperature detecting means is provided in accordance with the temperature of the ink detected by the ink temperature detecting means. The thermal head further comprises a perforation energy adjusting means for adjusting the perforation energy supplied to the miniaturized heating element to a predetermined perforation energy.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention including embodiments (hereinafter, referred to as "embodiments") will be described below with reference to the drawings. Members and components having the same function, shape, and the like will be denoted by the same reference numerals throughout the related art examples and embodiments to be described later, and description thereof will be omitted as much as possible. For the sake of simplicity of the drawings and description, members and components that do not need to be particularly described in the drawings, even if they are to be shown in the drawings, are omitted as appropriate.

First, the overall configuration and operation of a digital thermosensitive plate making and printing apparatus to which the present embodiment is applied will be described with reference to FIG. In FIG. 14, reference numeral 50 denotes
3 shows an apparatus body frame. The portion indicated by reference numeral 80 at the top of the apparatus body frame 50 constitutes a document reading device,
A portion indicated by reference numeral 200 below the plate making apparatus to which the first embodiment is specifically applied, a portion indicated by reference numeral 100 on the left side thereof is a printing drum device on which a porous printing drum 101 is disposed, and a reference numeral 70 on the left side thereof. The part indicated by is a plate discharging device, the part indicated by reference numeral 110 below the plate making apparatus 200 is a paper feeder, the part indicated by reference numeral 120 below the printing drum 101 is a printing pressure device, and the lower left reference numeral 130 of the apparatus main body frame 50 is indicated by reference numeral 130. The illustrated portions each indicate a paper discharge device. In this plate making printing apparatus, a digital thermal plate making type plate making apparatus 200 is integrally mounted on an apparatus main body frame 50.

The operation of the plate-making printing apparatus will be described below. First, an original 60 having an image to be printed is placed on an original placing table (not shown) arranged above the original reading device 80, and a plate making start key (not shown) is pressed. With the press of the plate making start key, a plate discharging process is first executed. That is, in this state, the used master 12 used in the previous printing remains mounted on the outer peripheral surface of the printing drum 101 of the printing drum device 100.

The printing drum 101 is rotated in the counterclockwise direction, and the rear end of the used master 12 on the outer peripheral surface of the printing drum 101 is moved to the plate discharging peeling roller pair 71 in the plate discharging device 70.
a, 71b, the pair of rollers 71a, 71b rotates and scoops up the rear end of the used master 12 with one of the plate discharge rollers 71b while rotating.
a, 71b, a plate discharging roller pair 73a, 73 disposed to the left of
b is discharged into the plate discharge box 74 while being conveyed in the direction of arrow Y1 by the plate discharge conveyance belt pair 72a, 72b stretched between the plate discharge separation roller pair 71a, 71b. The plate is peeled off from the outer peripheral surface, and the plate discharging process is completed. At this time, the printing drum 101 continues to rotate in the counterclockwise direction. The used master 12 that has been peeled and discharged is thereafter compressed inside the plate discharge box 74 by the compression plate 75.

In parallel with the plate discharging process, the original reading device 80 reads the original. In other words, the document 60 placed on the document table (not shown) is conveyed in the directions of arrows Y2 to Y3 by the rotation of the separation roller 81, the front document conveyance roller pairs 82a and 82b, and the rear document conveyance roller pairs 83a and 83b. While reading, it is subjected to exposure reading. At this time, if there are many originals 60, the separation blade 84
Only the lowermost document is conveyed. Manuscript 60
Is read by a mirror 87 which reflects reflected light from the surface of the original 60 illuminated by a fluorescent lamp 86 while being conveyed over a contact glass 85, passes through a lens 88, and passes through a CCD (photoelectric conversion element such as a charge-coupled device). ) Is performed by causing the light to enter the image sensor 5. The original 60 from which the image has been read is discharged onto the original tray 80A. The electric signal photoelectrically converted by the image sensor 5 is input to the analog / digital (A / D) converter 4 shown in FIG.

On the other hand, in parallel with this image reading operation,
A plate making and plate feeding process is performed based on the digitalized image information. That is, the master 12 is provided with the plate making device 2.
The master 12 is set at a predetermined position so as to be able to be fed out, and is pulled out from a master roll 12A formed by being wound in a roll around a core tube 12a.
01 is conveyed to the downstream side in the sub-scanning direction F (also a master conveyance direction) by the rotation of the platen roller 16 and the pair of tension rollers 17a, 17b which are pressed through the master 12. Master 12 conveyed in this way
On the other hand, as shown in FIG.
A plurality of minute heating elements 210 arranged in a line in the main scanning direction S selectively generate heat in accordance with the digital image signal sent from the A / D converter 4, and the heating elements that generate heat The thermoplastic resin film portion of the master 12 that is in contact with 210 is heat-melted and perforated. As described above, the image information is written as a punching pattern by the position-selective fusion punching of the master 12 according to the image information.

The platen roller 16 is connected to the platen drive motor 11 via a rotation transmission member (not shown) such as a timing belt and gears, and is rotated by the platen drive motor 11. Platen drive motor 11
Consists of, for example, a stepping motor. The rotational driving force of the platen drive motor 11 is transmitted to a pair of tension rollers 17a and 17b via a rotation transmitting member (not shown) such as a gear.
Further, the power is transmitted to a pair of upper and lower reversing rollers 18a and 18b via an electromagnetic clutch (not shown).

The leading end of the stencil master 12 on which the image information has been written is sent out toward the outer peripheral side of the printing drum 101 by the pair of reversing rollers 18a and 18b while being guided on the guide plate 19A. The traveling direction is changed downward by 19B, and the print drum 101 hangs down toward the expanded master clamper 102 (shown by a virtual line) of the printing drum 101 at the plate feeding position shown in the figure. At this time, the used master 12 has already been removed from the printing drum 101 by the plate discharging process.

Then, the leading end of the master 12 that has been made is
When the printing drum 101 is clamped by the master clamper 102 at a fixed timing, the printing drum 101 gradually winds the stencil master 12 around the outer peripheral surface while rotating in the direction A (clockwise) in the drawing. The rear end of the master 12 having been made is cut by the cutter 13 into a predetermined length.

When the master 12 on which one plate has been made is wound around the outer peripheral surface of the print drum 101, the plate making and plate feeding steps are completed, and the printing step is started. First, the uppermost one of the printing papers 62 stacked on the paper feed table 51 is fed by the paper feed roller 111 and the separation roller pairs 112a and 112b toward the registration roller pairs 113a and 113b in the direction of arrow Y4. And a pair of registration rollers 113a, 11
The print is sent to the printing pressure device 120 at a predetermined timing synchronized with the rotation of the printing drum 101 by 3b. The print paper 62 sent out includes a print drum 101 and a press roller 103.
, The press roller 103, which has been separated below the outer peripheral surface of the print drum 101, is moved upward to be pressed by the plate-making master 12 wound on the outer peripheral surface of the print drum 101. You. Thus, the printing drum 10
Ink oozes from the perforated portion 1 and the perforated pattern portion (both not shown) of the master 12 having been made, and the oozed ink is transferred to the surface of the printing paper 62 to form a printed image.

At this time, on the inner peripheral side of the printing drum 101, an ink reservoir 107 formed between the ink roller 105 and the doctor roller 106 from the ink supply pipe 104.
The ink is supplied to the inside of the printing drum 101 by an ink roller 105 that rotates in contact with the inner peripheral surface while rotating in the same direction as the rotation direction of the printing drum 101 and in synchronization with the rotation speed of the printing drum 101. It is supplied to the peripheral side.

The printing paper 62 on which the printing image has been formed by the printing pressure device 120 is peeled off from the printing drum 101 by the discharge peeling claw 114 of the paper discharging device 130, and is sucked by the suction fan 118, while being sucked by the suction discharging inlet 118. Due to the counterclockwise rotation of the transport belt 117 wrapped around the roller 115 and the suction / discharge exit roller 116, the transport belt 117 is transported toward the paper discharge device 130 as indicated by an arrow Y5, and is sequentially discharged and stacked on the paper discharge table 52. Is done. In this way, the so-called plate printing is completed. Next, the number of prints is set using a numeric keypad (not shown), and a print start key (not shown) is pressed. In the same process as the above-described printing, each of the paper feeding, printing, and discharging processes is repeated by the set number of prints. Then, all the steps of the stencil printing are completed.

(Embodiment 1) Embodiment 1 will be described with reference to FIGS. 1 to 10 and FIG. FIG.
In the figure, reference numeral 10 in parentheses indicates the plate making device in the first embodiment. The plate making apparatus 10 is different from the conventional plate making apparatus 200 shown in FIG.
1 is different from that of FIG. 1A mainly in that a thermal head 1 shown in parentheses in FIG.

As shown in FIG. 1B, the thermal head 1 has a plurality of heating elements 21 of a thermal head 201 having a plurality of minute heating elements 210 arranged in a line in the main scanning direction S.
A plurality of miniaturized heating elements 20 which are miniaturized from the size of 0 and are driven to generate heat simultaneously corresponding to one pixel of image data in the main scanning direction S and the sub-scanning direction F. A plurality of (two in the first embodiment) miniaturized heating element groups 25 are provided, and a plurality of the miniaturized heating element groups 25 are arranged in the main scanning direction S. Therefore, as a unit of the heating means which is driven to generate heat simultaneously corresponding to one pixel of the image data, one heating element 210 is used in the conventional thermal head 201 and four miniaturizations are used in the thermal head 1 of the first embodiment. One miniaturized heating element group 25 including the heating element 20 corresponds to each.

The details of the size of the miniaturized heating element group 25 and the miniaturized heating element 20 in the thermal head 1 according to the first embodiment, the perforation and heat generation distribution state thereby, and the heating element 210 in the conventional thermal head 201 will be described below. In order to make it easier to understand the details of the size and the like and the state of perforation and heat generation by this, they will be shown in one drawing as appropriate and compared. For the same purpose, the first embodiment
Thermal head 1 and conventional thermal head 201
Will be described with a configuration example referred to as a planar thermal head among the thin-film thermal heads, and with both the miniaturized heating element 20 and the heating element 210 having a rectangular shape.

FIG. 1B shows a conventional thermal head 2.
The enlarged planar shape when the vicinity of the heating element 210 in No. 01 is seen through a protective film (not shown) is shown. That is, in FIG. 1B, reference numeral 211 denotes a common electrode also called a common electrode, reference numeral 212 denotes a lead electrode which is an individual electrode on the driver IC side, and reference numeral 213 denotes a main scanning direction S.
Is the main scanning resolution pitch of the heating element 210 in FIG.
Reference numeral 215 denotes a sub-scanning resolution pitch (or sub-scanning feed pitch) in the sub-scanning direction, and reference numeral 215 denotes a heating driving range which is a driving range corresponding to one pixel of image data. Is shown.

FIG. 1A shows an enlarged plan view of the vicinity of the miniaturized heating element 20 of the thermal head 1 according to the first embodiment as viewed through a protective film (not shown).
That is, in FIG. 1A, reference numeral 21 denotes a common electrode, reference numeral 22 denotes a lead electrode which is an individual electrode on the driver IC side, and reference numeral 23 denotes a main scanning resolution pitch of the miniaturized heating element 20 in the main scanning direction S. , 24 is the sub-scanning resolution pitch (or sub-scanning feed pitch) in the sub-scanning direction
Reference numeral 25, which is circled by a dashed-dotted line, indicates a heating driving range, which is a heating driving range corresponding to one pixel of image data. The sub-scanning resolution pitch 24 (or sub-scanning feed pitch 24) in the sub-scanning direction is the resolution pitch of the plate making device 10 itself, that is, the sub-scanning resolution pitch 24 (or sub-scanning feed pitch 24) of the plate making device 10 in the sub-scanning direction. is there.

FIG. 10 shows a cross-sectional structure of the thermal head 201 in the sub-scanning direction F. In the cross-sectional structure of the thermal head 1, parts other than common parts are given parentheses and their sizes are substantially ignored. It is shown for reference only. As shown in FIG. 10, each of the thermal heads 1, 201 has a base made of aluminum called a heat sink 46 at its lowermost portion, and a substrate made of ceramic on the heat sink 46. A heat insulating layer 44 made of glass, which is also called a glaze layer, is formed by printing on the substrate 45. A heating resistor layer 43 made of a tantalum (Ta) alloy material or the like is formed by vapor deposition on the heat insulating layer 44, and a common electrode 211 made of aluminum is formed on the heating resistor layer 43. The folded electrode portion 29, the lead electrodes 212 and 22, which are individual electrodes, and the common electrode 21 are formed by vapor deposition, respectively, and these may be collectively referred to as a lead electrode.

The area of the heating resistor layer 43 indicated by a satin pattern surrounded by the common electrode 211, the folded electrode portion 29, the lead electrodes 212 and 22, and the common electrode 21 is etched to form the heating element 210 or the heating element 210. The miniaturized heating elements 20 are respectively formed. Thus, the heating element 210
Is formed by connecting the common electrode 211 to one side of the heating resistor layer 43 and the lead electrode 212 to the other side. In the main scanning direction S of the thermal head 201, the heating element 210
Are arranged in an array. Each heating element 210
Each driver IC not shown via each lead electrode 211
It is connected to the. Hereinafter, in order to clarify the drawing, the shapes of the heating element 210 and the miniaturized heating element 20 and the like in plan view are shown in a satin pattern. The surface portions of the thermal heads 201 and 1, which are further upper portions of the heating element 210, the miniaturized heating element 20, the common electrodes 21 and 211, and the lead electrodes 22 and 212, are made of a Si-ON-based material. A layer called a protective film 41 formed by evaporation is formed. Such a flat type thermal head 201 is the most general type of a thin film thermal head, has a shape which is easy to manufacture, and it can be said that the thermal head 1 is substantially the same. Each common electrode 21, 211 and each lead electrode 2
2 and 212, when the driver IC selectively supplies current corresponding to one pixel of image data with a fixed line cycle, the electric energy is generated by the heating element 210.
Alternatively, the four miniaturized heating elements 20 of the miniaturized heating element group 25
Is converted to thermal energy. At this time, the Joule heat is generated by the current flowing through the heating element 210 and the miniaturized heating element 20, so that the master 1 that is in contact with the protection film 41 is contacted.
Heat is transmitted to the thermoplastic resin film portion of No. 2 to perform heat perforation and plate making.

As described above, the conventional thermal head 201
, One heating element 210 driven to generate heat corresponding to one pixel of the image data is one of a plurality of heating elements 210 arranged in one row in the main scanning direction S.
When the two heating elements 210 are driven to generate heat based on image data, heat is transmitted to the thermoplastic resin film portion of the master 12 and the resolution pitch 21 in the main scanning direction S is increased.
3. In the range surrounded by the resolution pitch 214 (or the sub-scanning feed pitch 214) in the sub-scanning direction F, that is, substantially the same perforation state as the heating driving range 215 is obtained.

On the other hand, in the thermal head 1 according to the first embodiment, a plurality of miniaturized heating elements 20 that are simultaneously driven to generate heat corresponding to one pixel of image data (the first embodiment).
4) are provided to form a miniaturized heating element group 25, and the plurality of miniaturized heating elements 20 are simultaneously driven to generate heat based on image data, so that a heat is applied to the thermoplastic resin film portion of the master 12. Is transmitted to the range surrounded by the resolution pitch 23 of the miniaturized heating element group 25 in the main scanning direction S and the resolution pitch 24 (or the sub-scanning feed pitch 24) in the sub-scanning direction F, that is, the heating drive range 25. It is characterized in that a plurality of (four in the first embodiment) independent perforations corresponding to the miniaturized heating element 20 can be obtained.

Next, with reference to FIGS. 2A and 2B, a description will be given of a point that the thermal head 1 according to the first embodiment and the conventional thermal head 201 have greatly different perforations. As described above, in the plate making apparatus 200 equipped with the conventional thermal head 201, as shown in FIG. 2B, the main scanning resolution pitch 213 and the sub scanning resolution pitch 214 (or Sub-scan feed pitch 21
In the perforated region 231 corresponding to 4), the independent perforations 230 were formed in the thermoplastic resin film portion of the master 12 by the heat generated by one heating element 210. On the other hand, in the plate making apparatus 10 equipped with the thermal head 1 of the present invention, as shown in FIG. 2A, the main scanning resolution pitch 23 and the sub-scanning resolution pitch 24 (or the sub-scanning resolution pitch 24) correspond to one image data. In the miniaturized perforated area 31 corresponding to the scanning feed pitch 24), the heat generated by the plural (four in the first embodiment) miniaturized heating elements 20 causes the master 1
A plurality of (four in the first embodiment) perforations 30 are formed in the second thermoplastic resin film portion. This is a set-off characteristic peculiar to a plate making printing apparatus (refers to a stain defect of the ink caused by the transfer of the ink on the surface of the printing paper of the previous print to the back side of the printing paper, not the surface of the printing paper discharged). This proves that the defect has a considerable effect.

As shown in FIGS. 3 (a) and 3 (b), this is perforated plate making corresponding to one pixel of the image data.
This can be better understood by examining the printed matter printed on the printing paper 39 by winding the masters 12, both of which have been prepressed and shown somewhat enlarged in a simulated manner, around the printing drum 101 of the prepress printing apparatus. Heating element 210 driven to generate heat corresponding to one pixel of image data using conventional thermal head 201
As shown in FIG. 3 (b), the perforated state of the master 12 obtained as described above has an independent perforation 230 formed therein, and the ink transfer to the printing paper 39 when printing is performed using the master 12 that has been made. The state immediately after this is as shown in an ink transfer state 230A. On the other hand, using the thermal head 1 of the present invention, the punching of the master 12 obtained by the four miniaturized heating elements 20 of the miniaturized heating element group 25 driven to generate heat corresponding to one pixel of the image data. The state is
As shown in FIG. 3A, each of the independent miniaturized perforations 30
Are formed, and the state immediately after the ink transfer to the printing paper 39 when printing is performed using the master 12 that has been made is the ink transfer state 30A.

3A and 3B, the state when the conventional thermal head 1 is used to transfer the ink to the printing paper 39 and the state of the thermal head 1 according to the present invention. The difference from the state when using the thermal head 1 is that the dispersibility of the ink is clearly better when the thermal head 1 of the present invention is used, and is similar to that when the conventional thermal head 201 is used. It is clear that excessive ink transfer can be reduced and the amount of ink transferred can also be reduced, which leads to saving of ink. As a result, a considerably effective solution can be obtained for the disadvantage of set-off printing apparatus described above. In addition, since the present invention expresses one pixel of image data with one dot, the present invention expresses the image with a large number of dots, so that a good print image can be obtained. In this case, there is also an advantage that white spots (also referred to as white spots and poor printing due to poor punching of white spots) become less noticeable.

When plate making and printing are performed using the thermal head 1, the probability of perforation when the thermoplastic resin film portion of the master 12 is perforated is improved, that is, perforation defects are reduced. This is shown in FIG.
Referring to FIGS. 4B and 4C, FIG.
When plate making is performed on the master 12 using the thermal head 1 of the first embodiment, the vicinity of the miniaturized heating element group 25 composed of four miniaturized heating elements 20 that are simultaneously driven to generate heat corresponding to one pixel of image data. The enlarged shape of the perforations 30 and the respective temperature distributions of the miniaturized heating element 20 and the surface portion of the thermal head 1 are shown. FIG. 4C shows a plate made on the master 12 using the conventional thermal head 201. In this case, one heating element 2 driven to generate heat corresponding to one pixel of image data
The enlarged shape of the perforation 230 near 10 and the respective temperature distributions of the heating element 210 and the surface portion of the thermal head 201 are shown. When the thermal head 1 is used, as shown in FIG. 4 (A), the size of the miniaturized heating element 20 is smaller than that of the heating element 210, and therefore, the steep mountain-shaped It shows a temperature distribution, easily concentrates heat, and is effective in increasing the peak temperature. If the peak temperature is increased and the heat is easily concentrated, it is effective for the first perforation of the thermoplastic resin film portion of the master 12, and is effective for the perforation failure as described above. In addition, the above-mentioned "first perforation"
In the case of perforating a thermoplastic resin film or the like, the perforation diameter has little relation to the perforation diameter, and means that the material is softened and the film itself is penetrated.

As shown in FIG. 4B, one of the image data
Two heating elements 34 driven to generate heat corresponding to the pixels are provided in the main scanning resolution pitch 23 and the sub-scanning resolution pitch 24
4 (A) in the first embodiment shown in FIG. 4 (A), it is also found that the miniaturized heating element Since Embodiment 20 is fine, the peak temperature can be increased, and heat can be easily concentrated. Embodiment 1 shown in FIG.
Is more effective for perforation failure and the like, and can reduce white spots (white spots) and the like as a printed image, so that a good printed image can be obtained. 4 also shows the separability of perforations formed in the thermoplastic resin film portion of the master 12.
In (B), the heating element 34 is long in the sub-scanning direction F, and when trying to obtain a perforated state corresponding to the sub-scanning resolution pitch 24 (or the sub-scanning feed pitch 24), a gentle mountain-shaped temperature distribution is shown. A perforation point between the two heating elements 34 corresponding to one pixel of the image data and the heating element 34 corresponding to the adjacent image data in the main scanning direction S, and a perforation point on the next line in the sub-scanning direction F And the like, the separability is deteriorated, and it is difficult to obtain independent perforations. Further, in FIG. 4B, when it is attempted to obtain one perforation 234 with two heating elements 34 corresponding to one pixel of the image data, a perforation state as shown in FIG. This is not preferable as a perforated state expressing one dot.

It is needless to say that in order to obtain the above-described various effects of reduction of set-off and the like, it is preferable that each perforation state is fine and perforation is independent, but FIGS. 4 (A) and 4 (B). ) And (C) are considered from the viewpoint of reducing set-off and the like. FIG.
(A), (B), and (C) show a miniaturized heating element group 25 composed of four miniaturized heating elements 20 that are simultaneously driven to generate heat corresponding to one pixel of image data, and one pixel of image data. One heating element 2 driven to generate heat corresponding to one pixel of image data is added to two heating elements 34 driven to generate heat simultaneously.
10, the temperature distribution on the surface of the miniaturized heating element 20, the heating element 34, and the heating element 210 when the energy for perforation is applied, and the perforations formed in the thermoplastic resin film portion of the master corresponding thereto. Are shown for easy comparison. The diameter of the perforations in the thermoplastic resin film portion of the master 12 varies depending on the material of the thermoplastic resin film to be used, but the perforation of the thermoplastic resin film near a certain temperature, that is, the perforation threshold temperature Tt (of the thermoplastic resin film). Contraction) stops, and FIG.
The lower part of (A), (B) and (C) shows the perforated state at that time. In FIG. 4A, four miniaturized heating elements 2 which are simultaneously driven to generate heat corresponding to one pixel of the image data.
In the vicinity of an intermediate position between adjacent ones in the main scanning direction S and the sub-scanning direction F of 0, a temperature distribution lower than the perforation threshold temperature Tt whose perforation diameter is substantially determined is shown, so that each independent perforation state Have gained. However, in FIG. 4B, the temperature T at which the diameter of the perforation is substantially determined is determined.
The size of the heating element 34 is large near the intermediate position between adjacent ones in the main scanning direction S of the heating element 34 which is driven to generate heat simultaneously corresponding to one pixel of the image data, and the heat capacity of the heating element 34 is larger than t. 4A shows a high temperature distribution because it is larger than that of FIG. 4A, and it is difficult to obtain an independent perforation state, and is shown in FIG. 4B. Such a perforated state results.

Next, another characteristic point when the thermal head 1 of the first embodiment is used will be described with reference to FIGS. 1 (a) and 1 (b). As described in the related art, when the original image having a high printing rate in the simultaneous energizing block is made with the conventional thermal head 201 in which the size is reduced, the common electrode 211 or the like of the thermal head 201 is used. Energy loss becomes large, and as a result, the thermal head 201
The perforated state differs due to the difference in the positions of the respective heating elements 210, and the same perforated state cannot be obtained. As a result, a considerable difference in print image density occurs, and print image density unevenness, that is, print image quality Will be worse. The reason why the energy loss in the common electrode 211 and the like becomes large with the miniaturization of the thermal head 201 is that the common electrode width 216 and the like of the common electrode 211 shown in FIG. In order to reduce the size of the thermal head 201,
It is one of the important items that the narrowing of the common electrode width 216 described above is important.
One of them. The electric resistance component at the common electrode 211 is
There is a relational expression of R = ρL / S, where R is the electric resistance at the common electrode, ρ is the resistivity different depending on the material forming the common electrode, L is the length of the common electrode, and S is the cross-sectional area of the common electrode. Are respectively shown. The fact that the width of the common electrode 211 is reduced corresponds to the fact that the cross-sectional area S in the above equation is reduced. Therefore, it can be seen from the above equation that if the material used as the common electrode and the length and thickness of the common electrode are constant, the electric resistance value of the common electrode in the thermal head 201 also increases. Therefore, it is conceivable to cancel the increase in electric resistance at the common electrode by changing the thickness of the common electrode, the length of the common electrode, and the material for the narrowing of the common electrode. There is a limit due to various problems such as the production of the thermal head and interference with the platen roller, etc., and it has not been possible to cancel.

Therefore, referring to the electric resistance at the common electrode 21 in the thermal head 1 of the first embodiment shown in FIG.
01 is much lower than the electric resistance of the common electrode 211. This means that the pattern of the common electrode 211 in the conventional thermal head 201 is close to the end face of the thermal head 201 in the main scanning direction S from the heating power supply connector (not shown) in the direction of the lead electrode 212. It is wired via Conversely, the common electrode 21 of the thermal head 1 of the first embodiment
This pattern is different from the pattern of the common electrode 211 of the conventional thermal head 201 and requires a considerably short wiring up to the power supply connector for heat generation in the direction of the lead electrode 22, and is the length of the common electrode 21 as described above. L can be considerably shortened, and the miniaturized heating element 20 driven to generate heat simultaneously corresponding to one pixel of image data.
However, this is because a plurality of N (four in the first embodiment) miniaturized heating elements 20 are connected in series as shown in FIG. In other words, the heating element 210 in the conventional thermal head 201 can be easily understood.
And miniaturized heating element 2 in thermal head 1 of Embodiment 1
Assuming that the ratio of the dimension in the main scanning direction S to the dimension in the sub-scanning direction is 1: 1 and the thicknesses and the materials are the same, the electrical resistance value is expressed by the above equation R
= ΡL / S. That is, the electric resistance value of the thermal head 1 of the first embodiment is smaller than that of the thermal head 201 of the related art in that the heating element 20 is smaller in series connection.
Since the number is N, a number N times is obtained. Therefore, an increase in resistance means that a flowing current can be suppressed, so that the above-described effect of energy loss at the common electrode can be considerably reduced. In addition,
When the electric resistance at the common electrode is high, the excess
From the above formula, there is also an advantage that the thickness of the miniaturized heating element 20 can be increased, and the life of the miniaturized heating element 20 can be extended.

To reduce the size of the thermal head 1,
As described above, one of the important items is how the common electrode width 216 can be reduced. According to the thermal head 1 of the first embodiment, the influence of the common electrode 21 can be considerably reduced as the folded electrode width 26, so that the width can be considerably reduced. It is quite effective.

Another advantage is that the folded electrode width 26
That the width of the thin film substrate 4 on the transport exit side of the master 12 on the downstream end face side in the sub-scanning direction F can be achieved.
9 or an aluminum heat radiating plate 46 at the end face thereof.
Can be reduced as much as possible, and the distance from the end face of the master 12 on the transport exit side to the miniaturized heating element 20 when the master 12 is brought into close contact with the thermal head 1 by the platen roller 16 can be shortened. At the same time, it means that the nip width on the thin film substrate from the end face on the transport exit side to the miniaturized heating element 20 can be shortened.
When the nip width on the thin film substrate from the end face of the master 12 on the transport outlet side to the miniaturized heating element 20 when the master 12 is brought into close contact with the thermal head 1 by the platen roller 16 is shortened, plate making is advantageous. This is very effective for any original image, especially for master contraction in the sub-scanning direction F caused by slippage caused by insufficient friction between the platen roller 16 and the master 12, and the master contraction is reduced as much as possible. This is extremely effective in that the dimensional reproducibility is extremely good, there is no plate-making wrinkles, etc., and an optimum print image can be formed. Further, in using the thermal head 1 of the first embodiment, there is an advantage that the thermal head 1 is less susceptible to variations in accuracy in assembling parts and the like in the plate making section.

Next, in the thermal head 1 according to the first embodiment, an optimum arrangement of adjacent ones of a plurality of miniaturized heating elements 25 arranged in the main scanning direction S corresponding to one pixel of image data. Describe the relationship. The distance between the outermost ends of the miniaturized heating elements 20 located at the outermost ends in the main scanning direction S of the miniaturized heating elements group 25 in the thermal head 1 is determined by the distance between the adjacent miniaturized heating elements in the main scanning direction S. The distance is preferably equal to or less than the distance obtained by multiplying the main scanning resolution pitch 23 of the body group 25 by 0.9. The reason is shown in FIG.
(B) and (C). 5 (A), (B),
In (C), a miniaturized heating element group 25 driven to generate heat corresponding to one pixel of image data within a range obtained by multiplying the main scanning resolution pitch 23 in the main scanning direction S described above by 0.9. Is not included, separation of perforated portions in each of the miniaturized heating elements 20 indicated by hatching, which are arranged to face each other in the main scanning direction S in each of the adjacent miniaturized heating elements 25. The problem that it becomes difficult to secure the performance occurs.
For example, a description will be given by taking each of the hatched microfabricated heating elements 20 as an example. When each of the hatched microfabricated heating elements 20 is simultaneously energized corresponding to one image data, FIG. As shown in FIG. 5C, two temperature distributions 36 having a mountain-like shape are obtained as shown in FIG. 5B, and the relationship with the perforation threshold temperature Tt when the thermoplastic resin film portion of the master 12 is perforated. A non-independent perforation 37 is formed by connecting the two perforations as shown.

Although not shown for the same reason, the fine heating element group 2 in the thermal head 1 is not shown.
5, the distance between the outermost ends of the miniaturized heating elements 20 located at the outermost ends in the subscanning direction F is multiplied by 0.9 with respect to the subscanning resolution pitch 24 in the subscanning direction F. It can be said that it is preferable that the distance be equal to or less than the distance. It should be noted that, in a plate making apparatus capable of variably setting the document conveying pitch, which is the reading speed of the document image, and also variably setting the sub-scanning resolution pitch in the sub-scanning direction F, ie, the feed pitch of the master 12, The distance may be equal to or smaller than the distance obtained by multiplying the sub-scanning resolution pitch 24 of the device 10 by 0.9.

Contrary to the above, when the adjacent miniaturized heating element groups 25 in the main scanning direction S and the sub-scanning direction F are arranged so as to be extremely adjacent to each other, The distance between the outermost ends of the miniaturized heating elements 20 located at the outermost ends in the main scanning direction S of the miniaturized heating elements 25 in FIG. 25, the distance between the outermost ends of the miniaturized heating elements 20 located at the outermost ends in the sub-scanning direction F of the miniaturized heating element group 25 is extremely short. In the case where the fine heating element group 25 in the sub-scanning direction F is arranged to be extremely short with respect to the sub-scanning resolution pitch 24, a plurality of miniaturizing heating elements which are driven to generate heat simultaneously corresponding to one pixel of image data are provided. 20, the reasons mentioned above Thus, instead of a plurality of independent perforations 30 corresponding to one pixel of the image data as shown in FIG. 4A, one perforation state results, but in this case, the above-described stencil printing apparatus is used. Although there is no effect on the reduction of the specific set-off, it is effective in that the resistance of the common electrode of the thermal head 1 can be increased and the common drop and the like can be suppressed. Therefore, when the problem of set-off disappears in the future due to the improvement of the printing process in the plate making printing apparatus or the like, the effect corresponding thereto is exerted even in the above-described arrangement state.

Referring to FIGS. 6 and 7, the first embodiment will be described.
A schematic control configuration and control target components when driving the thermal head 1 in the plate making printing apparatus and the plate making apparatus 10 and the thermal head 201 in the above-described conventional plate making apparatus 200 will be described. FIG. 7 shows a specific example of the thermal head temperature detecting means for detecting the temperature of the thermal head 1. To detect the temperature of the thermal head 1,
A thermistor 8 is used as a thermal head temperature detecting means. FIG. 1 shows the temperature detection location of the thermal head 1.
0, for example, a portion close to the surface portion of the center of the miniaturized heating element 20 surrounded by the common electrode 21 and the lead electrode 22 is desirable. Then, since the detection at that portion is almost impossible, the temperature of the thermal head main body is detected on the thermal head substrate 9 which is on the circuit substrate mounted on the thermal head 1 here. The location of the thermistor 8 is not limited to the location on the thermal head substrate 9, but may be
6 may be provided inside. 7, reference numeral 49 denotes a thin film substrate. The thin film substrate 49 includes the substrate 45, the heat insulating layer 44, the heating resistor layer 43,
1, a lead electrode 22, a protective film layer 41, and the like.

The temperature of the ink is detected using a thermistor or the like capable of detecting the temperature, and the temperature of the ink supplied to the inner peripheral surface of the printing drum 101 is directly detected as the detection location. Although it is desirable, the temperature of the ink at or near the portion where the ink reservoir 107 is formed inside the printing drum 101 may be detected.

In FIG. 6, the reading of the original image is performed by causing the reflected light of the original focused through the lens 88 to enter the image sensor 5 as described above, and the electric signal photoelectrically converted by the image sensor 5 is read. Is the A / D converter 4
Is converted into a digital signal, and the digitalized image signal is input to the image processing unit 3 for image processing. The image signal thus processed is input to the plate making unit 2. The image signal input to the plate making unit 2 is not limited to the signal read by the image sensor 5, but may be, for example, a signal input from a contact sensor or a personal computer. The image signal input to the plate making unit 2 is subjected to a control process such as heat history control, which is already known, or subjected to a control process such as a common drop correction control based on a print ratio correction control by the microprocessor 6. Above, in the plate making section 2, the thermal head 1 or the thermal head 2
For example, various signals are generated at the time of driving the 01.

The plate making unit 2 and the microprocessor 6 have a relationship of mutually transmitting and receiving signals, and the microprocessor 6 and the ROM 7 have a relationship of mutually transmitting and receiving signals. The ROM 7 stores in advance various data for drive control of the thermal head 1 as described later, that is, data and programs for performing thermal history control, printing rate correction control, and the like. The microprocessor 6
Depending on the temperature of the thermal head detected by the thermistor,
The thermal head temperature for adjusting the perforation energy supplied to the individual miniaturized heating elements 20 of the thermal head 1 to a predetermined perforation energy for each block for simultaneously energizing the plurality of miniaturized heating elements 25 It has the function of separate perforation energy adjusting means. The microprocessor 6
In accordance with the number of energization counted by the energization number counting means described later, each of the plurality of miniaturized heating element groups 25 is supplied with perforation energy to be supplied to the individual miniaturized heating elements 20 of the thermal head 1. Each block has a function of a perforation energy adjusting means for adjusting the drilling energy to a predetermined drilling energy. The microprocessor 6 supplies the energy for perforation supplied to the individual miniaturized heating elements 20 of the thermal head 1 to the plurality of miniaturized heating element groups 2 in accordance with the ink temperature detected by the thermistor as the ink temperature detecting means.
5 has a function of an ink temperature-dependent perforation energy adjusting means for adjusting the perforation energy to a predetermined perforation block for each block for energizing simultaneously.

The first embodiment of the present invention is used as a thermal head perforation energy adjusting means, an energization rate per perforation energy adjusting means or an ink temperature perforating energy adjusting means.
Although the microprocessor 6 is used in the stencil printing machine, a microcomputer or the like may be used. The supply of the drilling energy adjusted to the predetermined energy is performed in accordance with the image signal in accordance with the image signal.
May be carried out by changing the width of the energization pulse to the plurality of miniaturized heating elements 20 constituting the micro heating elements 20, or may be supplied to the plurality of miniaturized heating elements 20 forming the individual miniaturized heating element groups 25 according to image signals. This may be performed by changing the current value or the voltage value applied to the miniaturized heating element 20.

In the plate making and printing apparatus of the first embodiment, the microprocessor 6 is used, and the energy for perforation is supplied to the miniaturized heating element 20 of the thermal head 1 by changing the width of the energizing pulse. By counting the number of energizations actually applied to the micronized heating element 20 as the perforation energy adjusting means according to the energization rate, the number of prints to be perforated and made is counted, and the energization rate based on the energization rate which is also the counted printing rate Correction control (also referred to as print rate correction control), that is, the number of prints (printing) when power is supplied to the simultaneous energizing block in the power supply wire for heating the thermal head, the contact resistance of the connector, etc. in addition to the power loss at the common electrode described above The loss due to the difference in current due to the rate is also controlled as described above using the microprocessor 6 or the like.
In addition to this, the microprocessor 6 as the perforation energy adjusting means for each ink temperature changes the viscosity of the ink according to the ink temperature according to the ink temperature detected by the thermistor as the ink temperature detecting means.
The fact that the amount of ink ejected from the perforated portion 2 differs from that of the perforated portion can be controlled by controlling and correcting the perforated state (perforated diameter) formed in the thermoplastic resin film portion of the master 12 at the same time. Has become.

A technique for adjusting the perforation energy according to the temperature of the thermal head 1 and a technique for adjusting the perforation energy according to the temperature of the ink are described in, for example, JP-A-6-32.
The one disclosed in, for example, FIG. Also, as the technology related to the heat history control,
For example, one disclosed in FIG. 8 of JP-A-8-132584 may be used.

In the first embodiment, the thermal head 1 mounted on the plate making apparatus 10 is a flat type and a rectangular type as described above. However, the present invention is not limited to this. Well, the main scanning direction S of the thermal head
The minute heating elements and the miniaturized heating elements arranged in the array may be of a heat concentration type. In addition, the miniaturized heating element group 25 of the thermal head 1
Is not limited to the four miniaturized heating elements 20 constituting the present invention, but within the scope of presently and future ultra-fine processing technologies that can be realized,
Further, as far as the manufacturing cost and the various advantages described above are available, the heating element may be made up of a larger number of miniaturized heating elements that are further miniaturized.

(Example) An example which is a test result of an actual confirmation test based on the technical contents described in the first embodiment will be described. Hereinafter, the conditions of the confirmation test are listed.

= Confirmation test conditions = Environment: Temperature: 23 ° C., Humidity: 65% Rh (relative humidity) Thermal head: Conventional (thermal head 201: see FIG. 1B) Rectangular line thermal head 300 dpi Number of heating elements 1 / pixel Heating element size: (main scanning × sub-scanning) 50 × 30 μm The present invention (thermal head 1 ... see FIG. 1 (a)) U-shaped 2-line thermal head 300 dpi Number of miniaturized heating elements 4 / pixel Heating element size : (Main scanning × sub scanning) 20 × 20 μm In FIG. 1 (a), the ratio of the main scanning resolution pitch 23 to the main scanning length 27 of the miniaturized heating element group = 0.75. In FIG. Ratio of sub-scanning resolution pitch 24 to heating element group sub-scanning length 28 = 0.75 Sub-scanning feed pitch: 300 dpi Printing cycle: 3.0 ms / Line Number of divided drives: 2 Dynamic input power: Conventional (thermal head 201) P = 0.120 W The present invention (thermal head 1) P = 0.037 W Here, W (watt) is the input power to the heating resistor corresponding to one image data. means. Energizing pulse width: Conventional (thermal head 201) Tp1 / Tp2 = 1074/888 μs In the present invention (thermal head 1) Tp1 / Tp2 = 1072/839 μs Yes, the energizing pulse width varies depending on the printing rate, but a printing rate of 50% is representatively described. Filling in other conditions was omitted because of the huge amount of data. Plate-making printing device: Ricoh Co., Ltd., Priport VT6000 Printing speed: Standard speed (3 speeds = 90 sheets / min) Master: Prototype, a master in which a thermoplastic resin film is bonded to a porous support via an adhesive layer. The surface of the thermoplastic resin film has a layer made of a trace component such as an antistatic agent and an antistick agent. Ink: Ricoh Co., Ltd., Inkport VT-600 II (black) Printing paper: Picopy PPC paper TYPE 6200 A3 T-th chart: Fax. NO. 2 Standard chart Densitometer: Macbeth densitometer (Macbeth RD915 made by Macbeth) Set-off judgment: Based on in-house limit sample In the above test conditions, dpi is (dot / inch)
Is an abbreviation for The size of the thermal head 1 according to the present invention is A3 size, in which 3456 miniaturized heating elements 25 are arranged in a line in the main scanning direction S, and the size of the conventional thermal head 201 is as follows. In the A3 size, 3456 heating elements 210 are arranged in a line in the main scanning direction S. In the energization pulse width, Tp1 is the first pulse width in the previous one-line thermal history control, Tp1
2 represents the second pulse width. Chart: F
ax. NO. 2 The standard chart is F
ACSIMILE TEST CHART NO. 2 is a chart created for in-house evaluation using No. 2. The maximum value of the internal limit sample used for the set-off judgment is 5,
The larger the value, the better the set-off, and the smaller the value, the worse the set-off.

FIG. 8 shows a main part of a plate making apparatus 10A modified for the above-mentioned confirmation test. This plate making apparatus 10A is similar to that shown in FIG.
In comparison with the conventional plate making apparatus 200 shown in FIG. 1, the mounting position relationship between the thermal head 1 and the platen roller 16 in the sub-scanning direction F is described from the end face of the thin film substrate 49 of the thermal head 1 which is the transport outlet side of the master 12. The distance L closest to the end face of the thin film substrate 49 of the miniaturized heating element group 25 is set to 150 μm, and the miniaturized heating element of the thermal head 1 is placed in a nip formed by the thermal head 1 and the platen roller 16. The only difference is that the group 25 is arranged.

In the thermal heads 201 and 1 of the prior art and the present invention, the punching energy was set to make the print image density substantially the same under the above-described confirmation test conditions, and the effect was confirmed. , Number of repetitions N = 1
In this case, there is a risk that good results may be obtained by chance due to variations in the supply of the plate-making printing apparatus, the ink, the master 12, etc., and the way in which the printed printing paper 39 falls onto the paper ejection tray 52. When a confirmation test was performed with N = 3,
As shown in FIG. 11, although the print image density was almost the same, it was confirmed that set-off was effective in all N = 3 times. This is an effect due to a difference in ink transfer to the printing paper 39 shown in FIGS. 3A and 3B and the like.

In addition, the miniaturized heating element 2 of all the miniaturized heating element groups 25 in the printing rate of 100%, that is, the simultaneous energizing block, is used.
When a current of 0 is applied to the common electrode due to the above-mentioned common electrode and the like, the master 1
As a result of comparing and confirming the perforated state of the thermoplastic resin film portion of No. 2, almost the same perforated state was obtained for the product of the present invention regardless of the position of the thermal head (heating resistor), and the master was printed. Result, thermal head 1
Irrespective of the position of the miniaturized heating element 20, the substantially same print image density could be obtained. For the conventional product that was compared and confirmed, a confirmation test was performed with the thermal head 201 that was reduced in size. However, referring to FIG. 1B, a description will be given with reference to FIG. The thin film substrate 49 on the end face side of the thermal head 201 on the transport exit side
The distance from the end face of the thermal head 201 to the heating element 210 is 3.25 mm). However, although the print image density unevenness depending on the position of the heating element 210 of the thermal head 201 is slightly observed, it is a problem. Was not at the level to be. However, the thermal head 1 of the present invention
Level (the thermal head 1 on the transfer exit side of the master 12)
From the end face of the thin film substrate 49 on the end face side
5, the thermal head 1 is further reduced in size to a distance L = 150 μm to the miniaturized heating element 20 closest to the end face of the thin film substrate 49, in other words, the common electrode width 21
It can be easily inferred that when the width of No. 6 is further reduced, considerable print image density unevenness occurs. In any case, when the conventional product and the prototype product of the present invention were confirmed and tested, the product of the present invention was clearly better in terms of print image density unevenness. The obtained results are shown in Table 1 below. Since the results include variations in the supplies of the plate-making printing apparatus, the ink, the master 12, and the like, a confirmation test was performed with the number of repetitions N = 3. As a result, differences were found in all the results. The data of the print image density unevenness is shown below, and the value of the print image density unevenness is the maximum value in each data when the average value at 12 points measured along the main scanning direction S is the same. It was expressed as the density difference from the minimum value.

= Confirmation test condition 2 = Basically the same as Confirmation test condition 1, except that a chart having a solid printing rate of 100% and an energizing pulse width of 100% printing rate was used. The measurement was performed with the average image density at 12 points measured along the main scanning direction S being substantially the same.

[0067]

[Table 1]

Next, regarding the master shrinkage, the result 3 as shown in the following Table 2 was obtained. However, at the time of this confirmation test, in order to confirm the effect more clearly, as shown in FIG.
The front tension at a and 17b is absent, and the same back tension that does not cause plate-making wrinkles is applied to the master 12 drawn from the master roll 12A between the master receiving member 15 and the back tension roller 14 appropriately. A confirmation test was performed on both by pressing and applying a load. When the print image density was confirmed after this confirmation test, the print image densities were almost the same.

= Confirmation test condition 3 = Confirmation test condition 2 is basically the same as that of the confirmation test condition 2, except that a chart having a printing rate of 100% and a solid area of about 320 mm in the sub-scanning direction is used.

[0070]

[Table 2]

From the above result 3, when the number of repetitions was N = 3 and the conventional product and the product of the present invention were compared as the master shrinkage (image size reproducibility), the master shrinkage of the product of the present invention was about half that of the conventional product. It was confirmed that it was suppressed to. Also,
In the present embodiment, the thickness of the heating resistor layer 43 of the miniaturized heating element 20 of the thermal head 1 according to the present invention is about four times as thick as that of the heating element 210 of the conventional thermal head 201. . Therefore, the heating resistor layer 4
3 is one of the factors that greatly affect the thickness of the heating resistor layer 43 from the viewpoint of the life of the miniaturized heating element 20 and the heating element 210. There is also an advantage that a good result can be obtained as a life extension effect.

As described above, according to the first embodiment and its examples, when the master 12 is used to make the master 12 using the thermal head 1 in the plate making apparatus 10 or the plate making and printing apparatus equipped with the plate making apparatus 10, the plate should be made. Regardless of the image of the original, the power loss at the common electrode 21 or the like can be suppressed. Can be obtained at any position of the miniaturized heating element group 25 of the thermal head 1 driven to generate heat corresponding to one pixel of the image data, and a suitable perforation according to the resolution in the main scanning direction S and the sub scanning direction F. By forming an image and suppressing the master shrinkage in any original image in which the image to be made is an image to be made, the image size reproducibility is good and the print image density unevenness is small. An optimal print image can be formed, and at the same time, excessive transfer of the ink used in the plate-making printing apparatus to the printing paper can be reduced, thereby reducing the problem of set-off peculiar to the plate-making printing apparatus as much as possible. Since the number of points can be reduced, an optimum print image can be formed. In addition, with the miniaturization of the plate making apparatus 10 and the thermal head 1 mounted on the plate making and printing apparatus equipped with the plate making apparatus 10, higher efficiency in manufacturing can be achieved. Achieved, it is inexpensive for the user and can be reflected in the price of the product. In addition, the size of the thermal head 1 can be reduced and the amount of materials used can be reduced, thereby providing a more environmentally friendly product. Plate making device 1 that can produce many of these advantages
0 and a plate-making printing apparatus equipped with the plate-making apparatus 10 can be provided.

FIG. 12 shows a modification of the first embodiment. This modification is different from the first embodiment only in that a thermal head 1A is provided instead of the thermal head 1 in the first embodiment.
In FIG. 12, reference numeral 26A indicates a common electrode width of the thermal head 1A. The common electrode width 26A of the thermal head 1A is reduced according to the common electrode width 26 of the thermal head 1 of the first embodiment. The feature of the thermal head 1A shown in FIG. 12 is that, when the driver ICs respectively connected in the direction ahead of the lead electrode 22 are turned on, the operation similar to that of the thermal head 1 in FIG. A plurality of miniaturized heating elements 20 (four in FIG. 12) in the miniaturized heating element group 25 that are simultaneously driven to generate heat for one pixel simultaneously generate heat and perforate the thermoplastic resin film portion of the master 12. That is. The advantage of the thermal head 1A of this modified example is that, compared to the conventional thermal head 201, first, there are a plurality of miniaturized heating elements 20 that are simultaneously driven to generate heat corresponding to one pixel of image data. Since a plurality of perforations can be obtained, the set-off problem peculiar to the plate making printing apparatus can be reduced, and since the size of the miniaturized heating element 20 is minute, it is easy to concentrate heat as a temperature distribution in the miniaturized heating element 20. Further, since it is easy to increase the peak temperature, there is a great advantage that the probability of perforation is good and white spots (white spots) can be reduced.

However, the arrangement pattern of the common electrode 211 is the same as that of the conventional thermal head 201,
The electric resistance of the common electrode 211 is higher than that of the thermal head 1 shown in FIG. 1A. It also has the problem that it will occur.

(Embodiment 2) FIG. 13B shows Embodiment 2
FIG. 13A shows a thermal head 1B according to the first embodiment. Thermal head 1B
Is a miniaturized heating element 20 having a size equivalent to the size of the heating element 20 of the thermal head 1 of the present invention.
A plurality of miniaturized heating elements 25B are provided in the main scanning direction S, and a plurality of miniaturized heating elements 25B are arranged in the main scanning direction S.

The first embodiment shown in FIG.
Comparing the thermal head 1 with the thermal head 1B, when trying to obtain the same perforation state as the independent perforation state in FIG. Because the size of the body 20 is both fine,
The same perforation probability can be obtained. However, in the configuration of the thermal head 1B in FIG. 13B, the sub-scanning resolution pitch 24 (or the sub-scanning feed pitch 24) in the same sub-scanning direction F in FIG. If you try to make a plate,
The perforated state is a perforated state 3 as shown in FIG.
Since the print image becomes 0B, a problem occurs that the print image has a streak shape in the main scanning direction S. In order to solve the above-mentioned problem by increasing the perforating energy applied to the thermal head 1B, a considerable amount of perforating energy is required. Become. Conversely, if the one shown in FIG. 13B is used without causing the above-described problem, for example, the resolution of the thermal head 1 in the first embodiment is 300 dpi.
Then, the sub-scanning feed pitch 24B in the sub-scanning direction F is 6
00 dpi or the like (as shown in FIG.
Sub-scanning resolution pitch 24 (or sub-scanning feed pitch 24)
13B, that is, a feed pitch 24B in the sub-scanning direction as shown in FIG. 13B), and a perforation state similar to that shown in FIG. 13A may be obtained. There is a problem that the time becomes slower when the prepress writing cycle is the same, because the sub-scanning feed pitch is made finer. However, from the above example, the sub-scanning resolution pitch 24 (or the sub-scanning feed pitch 24) is set to 600 dpi or the like, and the image data in the sub-scanning direction F is also set to 600 dpi.
Use of a high-resolution image such as i has an advantage that a good image in the sub-scanning direction F can be obtained as a print image or the like.

Also in the second embodiment, the miniaturized heating element group 25
B, the distance between the outermost ends of each miniaturized heating element 20 located at the outermost end in the main scanning direction S is determined by the main scanning resolution pitch of the adjacent miniaturized heating elements 25B in the main scanning direction S. 23 is less than the distance multiplied by 0.9,
It is preferable for the same reason as described above.

The above-described plate making printing apparatus has been a so-called single-sided printing method for printing on one side of a printing sheet. Various proposals have been made. As an example of such a simultaneous double-sided printing method, see, for example,
No. 71996, Japanese Patent Application Laid-Open No. 9-234941 and Japanese Patent Application Laid-Open No. 11-1057, and the plate making printing apparatus of the present invention can be applied to the double-sided simultaneous printing method. It goes without saying that the plate making apparatus of the present invention can be applied and equipped. As described above, the present invention has been described with respect to the specific embodiments including the examples. However, the configuration of the present invention is not limited to the above-described embodiments and the like, and may be configured by appropriately combining these. It will be apparent to those skilled in the art that various embodiments and examples can be configured according to the necessity, application, and the like within the scope of the present invention.

[0079]

As described above, according to the present invention, it is possible to provide a novel plate-making apparatus and plate-making printing apparatus by solving the above-mentioned problems of the conventional apparatus. The effects of each claim are as follows. According to the first aspect of the present invention, there is provided a miniaturized heating element group in which a plurality of miniaturized heating elements that are simultaneously driven to generate heat corresponding to one pixel of image data are arranged in the main scanning direction and the sub-scanning direction. And, by arranging a plurality of the miniaturized heating elements in the main scanning direction, the energy at the common electrode due to the difference in the location of the miniaturized heating elements in the thermal head can be determined for any original image to be made. In a state where the influence of the loss is reduced, the thermoplastic resin film portion of the heat-sensitive master is hot-melted by Joule heat generated by the miniaturized heating element to be perforated / plate-formed, and as a perforated state of the perforated / plate-formed master, It is possible to obtain an optimal perforation state in which the perforations are independent and independent from each other at a position where any miniaturized heating element is arranged in the thermal head. And an image size reproducibility can be improved by being able to suppress the master shrinkage. As a result, it is possible to make the print image density uniform, thereby contributing to the formation of an optimum print image with less print image density unevenness and white spots. By reducing the transfer, it is possible to contribute to reducing the problem of set-off peculiar to the plate making printing apparatus. In addition, with the miniaturization of the thermal head mounted on the plate making device, it is possible to achieve high efficiency in manufacturing, and it is inexpensive for the user and can be reflected in the price of the product. The use of materials and the like can be reduced as a result of the development, and thus more environmentally friendly products can be provided.

According to the second aspect of the present invention, the distance between the outermost ends of each of the miniaturized heating elements located at the outermost end in the main scanning direction of the group of miniaturized heating elements is set in the main scanning direction. By setting the resolution pitch of the adjacent miniaturized heating elements to a distance equal to or less than 0.9 multiplied by 0.9, in addition to the effect of the invention according to claim 1, heat is generated simultaneously corresponding to one pixel of image data. The perforations in the thermoplastic resin film portion of the heat-sensitive master formed by the plurality of miniaturized heating elements constituting the driven miniaturized heating element group are adjacently driven to generate heat simultaneously according to other image data. Perforations independent of each other can be reliably formed in a state separated in the main scanning direction from perforations formed by a plurality of miniaturized heating elements constituting another miniaturized heating element group.

According to the third aspect of the present invention, there is provided a miniaturized heating element group in which a plurality of miniaturized heating elements which are simultaneously driven for heating corresponding to one pixel of image data are arranged in the main scanning direction. By arranging a plurality of the miniaturized heating elements in the main scanning direction, the energy loss of the common electrode due to the difference in the arrangement of the miniaturized heating elements in the thermal head can be reduced for any original image to be made. In a state where the influence is reduced, the thermoplastic resin film portion of the heat-sensitive master is hot-melted by the Joule heat generated by the miniaturized heating element and perforated / plate-making, and if it is not necessary to perform high-speed plate-making, the perforation / The perforated state of the master that has been made is uniform and fine, regardless of the location of any miniaturized heating elements in the thermal head, and each perforation is independent and optimal. State can be obtained, yet, the image size reproducibility can be improved by being able to suppress the master shrinkage. As a result, it is possible to make the print image density uniform, thereby contributing to the formation of an optimum print image with less print image density unevenness and white spots. By reducing the transfer, it is possible to contribute to reducing the problem of set-off peculiar to the plate making printing apparatus. In addition, with the miniaturization of the thermal head mounted on the plate making device, it is possible to achieve high efficiency in manufacturing, and it is inexpensive for the user and can be reflected in the price of the product. The use of materials and the like can be reduced as a result of the development, and thus more environmentally friendly products can be provided.

According to the fourth aspect of the present invention, the distance between the outermost ends of the miniaturized heating elements located at the outermost ends in the main scanning direction of the group of miniaturized heating elements is set in the main scanning direction. By setting the resolution pitch of adjacent miniaturized heating elements to a distance equal to or less than 0.9 multiplied by 0.9, in addition to the effect of the invention according to claim 3, simultaneously with one pixel of image data, Perforations in the thermoplastic resin film portion of the heat-sensitive master formed by a plurality of miniaturized heating elements constituting a group of miniaturized heating elements driven to generate heat are adjacent to each other, which are simultaneously driven to generate heat according to other image data. Perforations independent of each other can be reliably formed in a state separated in the main scanning direction from the plurality of miniaturized heating elements constituting the other miniaturized heating element groups.

According to the fifth aspect of the present invention, the distance between the outermost ends of each of the miniaturized heating elements located at the outermost end in the sub-scanning direction of the group of miniaturized heating elements is set in the sub-scanning direction. By setting the distance equal to or less than 0.9 obtained by multiplying the resolution pitch of the plate making apparatus by a distance, in addition to the effect of the invention described in claim 1 or 2, the fine pitch driven simultaneously by heating for one pixel of image data is obtained. Perforation in the thermoplastic resin film portion of the heat-sensitive master formed by the plurality of miniaturized heating elements constituting the heat-generating heating element group, in the perforated state corresponding to the image data in the front or rear line, that is, in the sub-scanning direction In the separated state, independent perforations can be reliably formed.

According to the sixth aspect of the present invention, the perforating energy adjusting means for each thermal head temperature is provided for perforating the thermal head according to the temperature of the thermal head detected by the thermal head temperature detecting means. By adjusting the energy for drilling to a predetermined energy for drilling, the effect of the invention according to any one of claims 1 to 5 can be obtained at any temperature of the thermal head.

According to the seventh aspect of the present invention, the perforation energy adjusting means for each energization rate determines the perforation energy supplied to the miniaturized heating element of the thermal head in accordance with the energization number counted by the energization number counting means. By adjusting the energy for punching, the effect of the invention according to any one of claims 1 to 6 can be obtained in any original image, that is, in the printing rate.

According to an eighth aspect of the present invention, there is provided a plate cylinder comprising the plate-making apparatus according to any one of the first to seventh aspects, wherein the master made by the plate-making apparatus is wound around the outer peripheral surface of the plate cylinder. An ink supply means for supplying ink to the master on the plate cylinder, wherein the printing paper is pressed against the master on the plate cylinder to perform printing on at least one side of the printing paper. In addition to the effects of the invention described in any one of 1 to 7, the print image density can be made uniform to form an optimum print image with less print image density unevenness and white spots. By reducing the excessive transfer of the used ink to the printing paper, it is possible to reduce the problem of set-off peculiar to the plate making printing apparatus.

According to the ninth aspect of the present invention, the perforating energy adjusting means for each ink temperature adjusts the perforating energy supplied to the miniaturized heating element of the thermal head according to the ink temperature detected by the ink temperature detecting means. By adjusting the energy for perforation to a predetermined value, the effect of the invention according to claim 8 can be obtained at any ink temperature.

[Brief description of the drawings]

FIG. 1A is an enlarged plan view of the vicinity of a miniaturized heating element of a thermal head according to a first embodiment of the present invention,
(B) is an enlarged plan view near a heating element of a conventional thermal head.

FIG. 2A is an enlarged plan view showing a perforated state in which a master is perforated by a miniaturized heating element of a thermal head according to the first embodiment of the present invention, and FIG. FIG. 3 is an enlarged plan view showing a perforated state in which a master has perforated the body.

FIG. 3A is an enlarged plan view showing the perforated state in FIG. 2A further enlarged, and FIG.
It is an enlarged plan view which expands and shows the perforation state in (b) further.

FIG. 4A is a diagram illustrating a heat generation surface temperature distribution and a perforated state by a miniaturized heating element of a thermal head according to the first embodiment of the present invention, and FIG. FIG. 7C is a view for explaining a heat generation surface temperature distribution and a perforated state by a miniaturized heating element whose body is elongated in the sub-scanning direction.
FIG. 7 is a diagram illustrating a heat generation surface temperature distribution and a perforated state by a heat generating element of a conventional thermal head.

FIG. 5A is a diagram illustrating a plurality of miniaturized heating elements adjacent to each other in a plurality of miniaturized heating elements arranged in the main scanning direction corresponding to one pixel of image data in the thermal head according to the first embodiment. FIG. 4B is a plan view of a main part showing an inappropriate arrangement relationship of FIG.
FIG. 3C is a diagram showing a heat generation surface temperature distribution between adjacent fine heating elements in the same miniaturized heating element group, and FIG. It is a top view of the important section showing the perforated state where the master was perforated by driving.

FIG. 6 is a control block diagram of a plate-making printing apparatus to which the present invention is applied.

FIG. 7 is a side view of a main part showing a place where a thermistor for detecting the temperature of the thermal head is arranged.

FIG. 8 is a side view of a main part for explaining an arrangement position of a miniaturized heating element group from an end face of the thin film substrate of the thermal head according to the first embodiment.

FIG. 9 is a front view of a main part for explaining the presence / absence of front tension and back tension with respect to the master during master press punching and plate making.

FIG. 10 is a cross-sectional view of a main part showing a cross-sectional structure of a thermal head according to the related art and a thermal head according to the first embodiment.

11 is a graph showing a comparison between print image qualities of a conventional plate-making printing apparatus and a plate-making printing apparatus of an example in the first embodiment. FIG.

FIG. 12 is an enlarged plan view of the vicinity of a miniaturized heating element of a thermal head according to a modification of the first embodiment.

FIG. 13A is a diagram illustrating a heat generation surface temperature distribution and a perforated state by four miniaturized heating elements constituting one miniaturized heating element group of the thermal head according to the first embodiment, and FIG. Indicates one of the thermal heads in the first embodiment.
FIG. 4 is a diagram illustrating a heat generation surface temperature distribution and a perforation state by two miniaturized heating elements arranged side by side in the main scanning direction that constitute one miniaturized heating element group.

FIG. 14 is a configuration diagram of a plate-making printing apparatus to which the first embodiment and the like are applied.

[Explanation of symbols]

1, 1A, 1B thermal head 6 thermal head temperature perforation energy adjusting means,
Microprocessor as perforation energy adjusting means by conduction rate, perforation energy adjusting means by ink temperature, means for counting the number of energization 8 Thermistor as thermal head temperature detecting means 10 Plate making device 20 Fine heating element 21 Common electrode 23 Main scanning resolution pitch 24 Sub-scanning resolution pitch 25 Miniaturized heating element group 30 Perforation F Sub-scanning direction S Main scanning direction

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yasumitsu Yokoyama, 3rd, Nakamei, Shinmei-do, Shibata-cho, Shibata-cho, Miyagi Prefecture Tohoku Ricoh Co., Ltd. (72) Inventor Hajime Kato Shibata-cho, Shibata-gun, Miyagi F-term (reference) in Tomei Tohoku Ricoh Co., Ltd., No. 3, Nakamei Ichimyo Shinmei-do 2H084 AA13 AA32 AE05 BB04 CC09

Claims (9)

[Claims] 1. A thermal head having a plurality of heating elements is brought into contact with a thermosensitive master having a thermoplastic resin film in a main scanning direction, and the thermosensitive master is perpendicular to the main scanning direction with respect to the thermal head. In a plate making apparatus for making a plate while relatively moving in a sub-scanning direction, a plurality of miniaturized heating elements which are simultaneously driven to generate heat corresponding to one pixel of image data are provided in the main scanning direction and the sub-scanning direction, respectively. A plate-making apparatus, comprising: a group of miniaturized heating elements, wherein a plurality of the miniaturized heating elements are arranged in the main scanning direction. 2. The plate-making apparatus according to claim 1, wherein a distance between outermost ends of the miniaturized heating elements located at an outermost end in the main scanning direction of the miniaturized heating element group is defined as: A plate making apparatus characterized in that the distance is equal to or less than a value obtained by multiplying a resolution pitch of adjacent fine heating elements in the main scanning direction by 0.9. 3. A thermal head having a plurality of heating elements in a main scanning direction is brought into contact with a thermosensitive master having a thermoplastic resin film, and the thermosensitive master is perpendicular to the main scanning direction with respect to the thermal head. In a plate making apparatus for making a plate while relatively moving in the sub-scanning direction, a group of miniaturized heating elements in which a plurality of miniaturized heating elements that are simultaneously driven to generate heat corresponding to one pixel of image data are arranged in the main scanning direction. And a plurality of the miniaturized heating elements arranged in the main scanning direction. 4. The plate-making apparatus according to claim 3, wherein the distance between the outermost ends of the miniaturized heating elements located at the outermost ends in the main scanning direction of the group of miniaturized heating elements is defined as: A plate making apparatus, wherein the distance is set to be equal to or less than a value obtained by multiplying a resolution pitch of the adjacent miniaturized heating elements in the main scanning direction by 0.9. 5. The plate-making apparatus according to claim 1, wherein a distance between outermost ends of each of the miniaturized heating elements located at an outermost end in the sub-scanning direction of the group of miniaturized heating elements. Is less than a distance obtained by multiplying the resolution pitch of the plate making device in the sub-scanning direction by 0.9. 6. The plate making apparatus according to claim 1, further comprising: a thermal head temperature detecting means for detecting a temperature of the thermal head, wherein the thermal head temperature detecting means detects the temperature of the thermal head. A perforation energy adjusting means for adjusting the perforation energy supplied to the miniaturized heating element of the thermal head to a predetermined perforation energy in accordance with the temperature of the thermal head. 7. The plate making apparatus according to claim 1, further comprising: a current supply number counting means for counting the number of currents actually supplied to each of the miniaturized heating elements; In accordance with the number of energizations counted by the means, there is provided a perforation rate-specific perforation energy adjusting means for adjusting perforation energy supplied to the miniaturized heating element of the thermal head to predetermined perforation energy. Plate making equipment. 8. A plate cylinder comprising the plate making device according to claim 1, wherein the master made by the plate making device is wound around an outer peripheral surface of the plate cylinder, and a master on the plate cylinder. An ink supply unit for supplying ink to the plate cylinder, wherein the printing paper is pressed against a master on the plate cylinder to perform printing on at least one side of the printing paper. 9. The plate-making printing apparatus according to claim 8, further comprising an ink temperature detecting means for detecting a temperature of the ink, wherein the temperature of the thermal head is adjusted according to the temperature of the ink detected by the ink temperature detecting means. A plate-making printing apparatus, comprising: perforation energy adjusting means for adjusting ink temperature perforating the perforation energy supplied to the miniaturized heating element to a predetermined perforation energy.