JP2000334908A - Plate-making apparatus and plate-making printing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformize the perforation state of a master obtained by melt perforation and plate making regardless of the position of a heating element by suppressing power loss in a common electrode or the like even with respect to any manuscript image to be subjected to plate making in making the master using the thermal head of a plate-making apparatus or plate-making printing apparatus and to ensure the separability in a sub-scanning direction in order to make perforations independent mutually in the sub-scanning direction even in continuous printing. SOLUTION: The common electrode 21 connected to one end of a thermal head 1 in a sub-scanning direction F and arranged on the membrane substrate of a master discharge side 38 is folded back on the side opposite to the master discharge side 38 to be arranged between adjacent heating elements 20 and the length 28 in the sub-scanning direction of the heating elements 20 is made equal to or shorter than the length 27 in the main scanning direction thereof.

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 apparatus, and more particularly, to a plate making apparatus having a thermal head for making a plate on a heat-sensitive master and a plate making apparatus having the plate making apparatus.

[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 perforated plate-making as described above. Since the external shape of a thermal head mounted on a plate-making device or a plate-making printing device until a long time ago is relatively large, the common electrode width of the thermal head does not significantly affect the heat generation efficiency of the thermal head. Since the thermal head has been used, the thermal head can be driven by using thermal history control, which is a known technique, without considering the energy loss (power loss) at the common electrode in the simultaneous energizing block of the thermal head. A punching energy was applied to each heating element of the head to pierce the thermoplastic resin film portion of the master, thereby obtaining a printed image. The energy loss (power loss) at the common electrode in the thermal head is described in, for example, JP-A-61-14.
No. 1572 and the like.

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, in recent years, thermal heads have been reduced in size for the above-described reasons and the like. In this case, when the printing rate in the simultaneous energizing block is high, there is a problem that a considerable print image density difference occurs in the print image corresponding to the main scanning direction of the thermal head. In addition,
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 and the like caused by a voltage drop caused by the electric resistance of a common electrode in a thin film substrate provided in a thermal head. Because 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. Also,
When a conventional thermal head prints a document image having a particularly high printing rate, the master contracts (especially the contraction of the master in the sub-scanning direction caused by slippage caused by insufficient friction between the platen roller and the master: general). (Referred to as a stick). 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. .

Accordingly, the present invention has been made in view of the above-described 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, by suppressing the power loss at the common electrode, etc., it is possible to obtain a uniform perforated state of the melt-punched / plate-made master regardless of the position of the heating element. Ensure the separation in the sub-scanning direction to be independent from each other in the scanning direction,
By suppressing the master shrinkage caused by the melt perforation, a good image dimensional reproducibility can be obtained, and an optimum print image with little unevenness in print image density can be formed. By reducing the excess transfer of the ink used to the printing paper, it is possible to considerably reduce the problem of set-off, which is peculiar to plate-making printing equipment. In addition to achieving high efficiency in manufacturing, it is inexpensive for the user and can be reflected in the price of the product, and the size of the thermal head can be reduced and the amount of material used can be reduced, so that it is more environmentally friendly It is an object of the present invention to provide a plate-making apparatus and a plate-making printing apparatus which can provide a product and can obtain many of these advantages.

[0008]

Means for Solving the Problems In order to solve the above-mentioned problems, the invention described in each claim has the following configuration. In the invention according to claim 1, a thermal head having a plurality of heating elements arranged in a main scanning direction on a thin film substrate is brought into contact with a thermosensitive master having a thermoplastic resin film, and the thermal head is contacted with the thermal head. In a plate making apparatus for making a plate while relatively moving the heat-sensitive master in a sub-scanning direction orthogonal to the main scanning direction, the plate-making apparatus is connected to one end of each of the heating elements on the side of the sub-scanning direction and discharges the heat-sensitive master. The common electrode disposed on the thin film substrate on the side is folded back to the side opposite to the heat-sensitive master discharge side and disposed between the adjacent heating elements.

According to a second aspect of the present invention, in the plate making apparatus according to the first aspect, the common electrode between at least two of the heating elements continuously arranged in the main scanning direction is a dummy electrode. There is a feature.

According to a third aspect of the present invention, in the plate making apparatus of the first or second aspect, the length of each heating element in the sub-scanning direction is equal to or shorter than the length of each heating element in the main scanning direction. Is also shortened.

According to a fourth aspect of the present invention, in the plate making apparatus according to the first, second, or third aspect, there is provided a thermal head temperature detecting means for detecting a temperature of the thermal head, and the thermal head temperature detecting means detects the temperature. A thermal head temperature-dependent drilling energy adjusting means for adjusting the drilling energy supplied to the heating element of the thermal head to a predetermined drilling energy in accordance with the temperature of the thermal head.

[0012] The invention according to claim 5 is the invention according to claims 1 to 4.
In the plate making apparatus according to any one of the above, the engraving apparatus has energization number counting means for counting the energization number actually energized to each of the heating elements, according to the energization number counted by the energization number counting means,
The thermal head further includes a perforation rate-specific perforation energy adjusting means for adjusting perforation energy supplied to the heating element to a predetermined perforation energy.

The invention according to claim 6 is the invention according to claims 1 to 5
A plate cylinder for winding the master made by the plate making apparatus around the outer peripheral surface of the plate cylinder, and an ink supply means for supplying ink to the master on the plate cylinder. And printing on the printing paper by pressing the printing paper against the master on the plate cylinder.

According to a seventh aspect of the present invention, in the plate-making printing apparatus according to the sixth aspect, there is provided an ink temperature detecting means for detecting the temperature of the ink, wherein the ink temperature detecting means detects the temperature of the ink. A perforating energy adjusting means for adjusting the perforating energy supplied to the heating element of the thermal head to a predetermined perforating energy.

[0015]

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. The members and components having the same function, shape, and the like will be denoted by the same reference numerals throughout the related art examples, the embodiments, and the like described below, and the 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. 10, 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 discharge roller pair 71 in the plate discharge 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 in the master 12 as a perforation pattern by the position-selective fusion perforation 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 prepressed master 12 on which the image information is 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, and the plate feed guide plate is provided. The direction of travel is changed downward by 19B, and the print drum 101 hangs down toward the expanded master clamper 102 (shown by a phantom line) of the printing drum 101 in the illustrated plate feeding position state. 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 prepressed master 12 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 printing 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. 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.
Will be described. In FIG. 10, reference numeral 10 in parentheses indicates the plate making device in the first embodiment. The plate making apparatus 10 differs from the conventional plate making apparatus 200 shown in FIG. 10 in that the thermal head 201 shown in detail in FIG. 1A and shown in parentheses in FIG. The main difference is having.

The thermal head 1 is shown in FIG.
With respect to the conventional thermal head 201 shown in FIG.
A plurality of minute heating elements 2 arranged in a line in the main scanning direction S
10 has a plurality of heating elements 20 each having a specific size different from the size of each heating element 210 of the thermal head 201 including the thermal head 201, and is connected to one end of each heating element 20 on the sub-scanning direction F side. Master discharge side 38
The main difference is that the common electrode 21 disposed on the other side is turned back to the side opposite to the master discharge side 38 and disposed between the adjacent heating elements 20.

The structure around the common electrode 21 (also called the common electrode) and the size of the heating element 20 in the thermal head 1 of the first embodiment, the structure around the common electrode 211 in the conventional thermal head 201, and The details such as the size of the heating element 210 are shown in FIG. 1 for easy understanding, and will be described in comparison. For the same purpose, both the thermal head 1 of the first embodiment and the conventional thermal head 201 have a configuration example referred to as a planar thermal head among the thin-film thermal heads, and include the heating element 20 and the heating element 2.
10 will be described using an example of 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 212 denotes a lead electrode which is an individual electrode on the driver IC side, reference numeral 213 denotes a main scanning resolution pitch of the heating element 210 in the main scanning direction S, and reference numeral 214 denotes a sub scanning direction F. The sub-scanning resolution pitch (or sub-scanning feed pitch), reference numeral 216 indicates a common electrode width which is the width of the common electrode 211, reference numeral 217 indicates the main scanning direction length which is the length of the heating element 210 in the main scanning direction S, Reference numeral 218 denotes a heating element 210 in the sub-scanning direction F.
Are shown in the sub-scanning direction.

FIG. 1A shows an enlarged plan view of the vicinity of the heating element 20 of the thermal head 1 according to the first embodiment as seen 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, reference numeral 23 denotes a main scanning resolution pitch of the heating element 20 in the main scanning direction S, and reference numeral Reference numeral 24 denotes a sub-scanning resolution pitch (or sub-scanning feed pitch) in the sub-scanning direction.
Reference numeral 16 denotes a common electrode width which is the width of the common electrode 21, reference numeral 27 denotes a length in the main scanning direction which is the length of the heating element 20 in the main scanning direction S, and reference numeral 28 denotes a length of the heating element 20 in the sub scanning direction F. Respectively in the sub-scanning direction.
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 F.
It is.

FIG. 9 shows a cross-sectional structure of a portion including the heating element 210 of the thermal head 201 in the sub-scanning direction F. In the cross-sectional structure of the thermal head 1, portions other than the common portion are indicated by parentheses. In addition, the size is almost ignored and shown for reference. Each thermal head 1,20
As shown in FIG. 9, a radiator plate 46 is provided at the bottom.
A base made of aluminum is formed, and a thin film substrate 45 made of ceramic is formed on the heat radiating plate 46, and a heat insulating material made of glass also called a glaze layer is formed on the substrate 45. The layer 44 is formed by printing. A heating resistor layer 43 made of a tantalum (Ta) alloy material or the like is provided on the heat insulating layer 44.
The common electrodes 211 and 21 made of aluminum and the lead electrodes 212 and 22 as individual electrodes are formed on the heating resistor layer 43 by vapor deposition, respectively. It may be called a lead electrode.

The common electrodes 211 and 21 and each lead electrode 2
The heating element 210 and the heating element 20 are respectively formed by performing etching on the area of the heating resistor layer 43 indicated by the satin pattern surrounded by 12, 122. As described above, 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. Are arranged in an array. Each heating element 210 is connected to each driver IC (not shown) via each lead electrode 212. Hereinafter, in order to clarify the drawing, the shape of the heating element 210, the heating element 20, and the like in plan view is shown by a satin pattern. A Si-ON-based material is vapor-deposited on the surface portions of the thermal heads 201, 1 which are further upper portions of the heating element 210, the heating element 20, the common electrodes 21, 211, the lead electrodes 22, 212, and the like. A layer called a protective film 41 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. When a current is selectively supplied between each of the common electrodes 21 and 211 and each of the lead electrodes 22 and 212 by one of the driver ICs with a fixed line cycle corresponding to one pixel of image data, the electric energy is generated. Body 21
The heat is converted into heat energy by the heat generating element 20 or the heat generating element 20. At this time, Joule heat is generated by the current flowing through the heat generating element 210 or the heat generating element 20, so that the Joule heat comes into contact with the thermoplastic resin film portion of the master 12 via the protective film 41. Heat is transmitted, and heat perforation and plate making are performed.

As described in connection with the prior art, when a conventional thermal head 201 having a small size is used to make a plate image of an original having a high printing rate, particularly in the simultaneous energizing block, the common electrode 211 of the thermal head 201 is required. Energy loss in the thermal head 20
1, the perforated state differs due to the difference in the position of each heating element 210 and the like, and the same perforated state cannot be obtained. As a result, a considerable difference in print image density occurs, and the print image density unevenness, that is, the print image density The quality is inferior. 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, the narrowing of the common electrode width 216 is one of the important items. The electrical resistance at the common electrode 211 has a relational expression of R = ρL / S, where R is the electrical resistance at the common electrode, ρ is the resistivity that varies depending on the material forming the common electrode, and L is the resistance of the common electrode. The length S indicates the cross-sectional area of the common electrode. Common electrode 21
The fact that the width of 1 is reduced corresponds to the fact that the cross-sectional area S in the above equation becomes smaller if the thickness of the common electrode is constant. 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 of the common electrode in the thermal head 201 also increases. Therefore, the width of the common electrode is reduced by changing the thickness of the common electrode, the length of the common electrode, and the material thereof.
Although it is conceivable to cancel the increase in the electric resistance value at the common electrode, at present, there are limitations due to various problems such as interference with the platen roller due to the manufacture of the thermal head,
I haven't been able to cancel.

Therefore, in the thermal head 1 according to the first embodiment shown in FIG. 1A, each of the heating elements 20 is connected to one end of the heating element 20 in the sub-scanning direction F, and on the thin film substrate 45 on the master ejection side 38. Of the common electrodes 21 disposed on the upstream side in the sub-scanning direction F, which is opposite to the master discharge side 38, and provided between the adjacent heating elements 20. And the point where the length 28 in the sub-scanning direction of each heating element 20 is equal to or shorter than the length 27 in the main scanning direction of each heating element 2, ie, the length 28 in the sub-scanning direction of each heating element 20 is The feature is that it is equal to or less than the length 27 in the main scanning direction of 20.

Therefore, in the thermal head 1 according to the first embodiment, the folded common electrode portions 21a disposed between the adjacent heating elements 20 act as a kind of heat insulating member, so that the heat is generated in the heating element 20. Since the diffusion of heat is suppressed, the perforated state of the master 12 perforated in the main scanning direction S can maintain the separability in the main scanning direction S even when the adjacent heating elements 20 generate heat simultaneously. it can. Also, since the length 28 in the sub-scanning direction of each heating element 20 is equal to or less than the length 27 in the main scanning direction of each heating element 20, the heat concentration is excellent, and the separability of the perforated state during continuous printing and perforating plate making is improved. As well as high-speed plate making. In addition, since the master shrinkage can be suppressed, the effect of suppressing the master plate making shrinkage can be obtained.

Further, since the heat generation peak temperature in each heating element 20 can be suppressed to the minimum necessary, the thermal head 1
You can extend your life. As a result, an optimum perforation state can be obtained by securing perforation separation in the main scanning direction S and the sub-scanning direction F at all resolutions of the thermal head 1 and the plate making device 10.

In the thermal head 1 according to the first embodiment, unlike the common electrode pattern of the conventional thermal head 201, the common electrode 20 is adjacent to the heating element 20.
Folded common electrode part 2 of the pattern folded between
1a is connected in the direction of the thermal head substrate 9 shown in FIG. 6, so that the sub-scanning of the lead electrode 22 is particularly performed in the heating element group near the center among the heating element groups arranged in a line in the main scanning direction S. The wiring to the heating power supply connector on the upstream side in the direction F is quite short, and as described above, L in the above equation corresponding to the common electrode width 25 up to the end of the common electrode 21 to the master discharge side 38 is very short. Thus, there is an advantage that the difference in resistance between the common electrodes 21 of the heating elements 20 arranged in a line in the main scanning direction S is reduced. Therefore, in the sub-scanning direction F, the common electrode width 25 facing the lead electrode 22 with the heating element 20 interposed therebetween can be reduced as much as possible within an appropriate range. Further, by grounding the folded common electrode portion 21 a to the thermal head substrate 9, a common electrode can be secured in the thermal head substrate 9, or the thickness of the common electrode film can be increased in the thermal head substrate 9. Alternatively, an increase in the resistance value due to the narrowing of the common electrode width 25 may be canceled.

Further, according to the thermal head 1 of the first embodiment, the width of the common electrode 25 in the thin film substrate 49 can be reduced, which is considerably effective for downsizing the thermal head 1 itself.

Another advantage is that the narrowed common electrode width 25 at the folded portion can be achieved.
The distance L from the end face 49a of the thin film substrate 49 on the master ejection side 38 at the downstream end side in the sub-scanning direction F of the thermal head 1 to the end face of the heating element 20 on the end face 49a side.
(See FIG. 7), the heating element 20
Can be brought as close as possible to the end face 49a of the thin film substrate 49 on the master discharge side 38. Thereby, the platen roller 1
When the heating element 20 is used as a contact in a contact area between the thermal head 1 and the thermal head 1, as a result, the platen roller 16
The distance from the contact to the master discharge side 38 can be reduced in the nip width centered on the contact formed by the close contact with the thermal head 1. When the nip width on the thin film substrate from the end face 49a on the master discharge side 38 to the heating element 20 when the master 12 is brought into close contact with the thermal head 1 by the platen roller 16 is shortened, the advantage of any original to be plate-made is The image is also very effective in contracting the master in the sub-scanning direction F caused by slippage caused by insufficient friction between the platen roller 16 and the master 12, which can be said to be unique to the plate making device and the plate making device. This is extremely effective because it reduces the reproducibility of the image dimensions, eliminates wrinkles and the like, and enables the formation of an optimal print image. Further, in using the thermal head 1 of the first embodiment, there is also an advantage that the thermal head 1 is less susceptible to variations in the accuracy of assembling parts and the like in the plate making section and variations in the position of the heating element 20 of the thermal head 1.

Referring to FIGS. 5 and 6, 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. 6 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. 9 shows the temperature detection location of the thermal head 1.
It is desirable that this is a portion close to the surface portion of the heating resistor layer 43, for example, the central portion of the heating element 20 surrounded between the common electrode 21 and the lead electrode 22. Since the detection at the portion is almost impossible, the temperature of the thermal head main body is detected on the thermal head substrate 9 which is 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 and may be provided inside the heat sink 46. The thin film substrate 49 shown in FIG.
Are the substrate 45, the heat insulating layer 44, the heating resistor layer 43, the common electrode 21, the lead electrode 22, and the protective film layer 41 shown in FIG.
Etc. are provided.

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. 5, the reading of the original image is performed by making the reflected light of the original focused through the lens 88 incident on the image sensor 5 as described above, and the electric signal photoelectrically converted by the image sensor 5 is obtained. 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 a signal input from, for example, 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 a heat history control, which is already known, or subjected to a control process such as a common drop correction control by a microprocessor 6 by a print ratio correction control. Above,
In the plate making section 2, various signals are generated when the thermal head 1 and the thermal head 201 are driven.

The plate making section 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,
Punching energy adjustment by thermal head temperature for adjusting perforation energy supplied to individual heating elements 20 of thermal head 1 to predetermined drilling energy for each block for simultaneously energizing a plurality of heating elements 20 groups. It has the function of means. The microprocessor 6 supplies perforation energy to be supplied to each heating element 20 of the thermal head 1 in accordance with the energization number counted by the energization number counting means described later.
Each block for simultaneously energizing the plurality of heating elements 20 has a function of a perforation rate-dependent perforation energy adjusting unit that adjusts to a predetermined perforation energy.

The microprocessor 6 transfers the drilling energy supplied to the individual heating elements 20 of the thermal head 1 to a plurality of heating elements 20 according to the temperature of the ink detected by the thermistor as the ink temperature detecting means. Each block for simultaneous energization has a function of a perforation energy adjusting means for adjusting ink temperature to a predetermined perforation energy.

In the first embodiment, the thermal energy perforation energy adjusting means according to the temperature, the perforation energy adjusting means according to the duty ratio, and the perforating energy adjusting means according to the ink temperature are used.
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 may be performed by changing the energizing pulse width to a plurality of heating elements 20 constituting the heating element group 20 of the thermal head 1 according to the image signal. Alternatively, the change may be performed by changing a current value flowing through the heating elements 20 constituting the individual heating element groups or a voltage value applied to the heating elements 20 in accordance with an image signal.

In the plate-making printing apparatus of the first embodiment, the heating element 2 of the thermal head 1 uses the microprocessor 6.
To 0, the drilling energy is supplied by changing the energizing pulse width, the heat history control is performed, and the number of currents actually passed through the heating element 20 is counted as the drilling energy adjusting means according to the duty ratio. The number of prints to be performed is counted, and the duty ratio correction control (also called print ratio correction control) based on the duty ratio which is also the counted print ratio, that is, in addition to the above-described power loss at the common electrode, a power supply wire for heating the thermal head, Number of prints (print rate) when power is applied to the simultaneous energizing block in the contact resistance of connectors etc.
The loss due to the difference in current caused by the above is also controlled at the same time using the microprocessor 6 or the like as described above. In addition to this, the microprocessor 6 as a perforation energy adjusting means for each ink temperature changes the viscosity of the ink depending on the ink temperature according to the temperature of the ink detected by the thermistor as the ink temperature detecting means. That the amount of ink ejected from
The control of controlling and correcting the perforated state (perforated diameter) formed in the thermoplastic resin film portion of the master 12 is also performed at the same time.

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 flat type and the rectangular type are used as the thermal head 1 mounted on the plate making apparatus 10 as described above. However, the present invention is not limited to this, and a partial glaze type or the like may be used. The minute heating elements arranged in the main scanning direction S of the head may be of a heat concentration type. (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 condition 1 = Environment: Temperature: 23 ° C., Humidity: 65% Rh (relative humidity) Thermal head: Comparative example (thermal head 201: see FIG. 1B) Rectangular line thermal head 300 dpi Number of heating elements 1 / Pixel Heating element size: (217 in the main scanning direction × 218 in the sub-scanning direction) 50 × 60 μm The present invention (Thermal head 1 ... see FIG. 1A) U-shaped line thermal head 300 dpi Number of heating elements 1 / pixel Heating element size: (main scanning direction length 27 × sub scanning direction length 28) 50 × 30 μm sub-scanning feed pitch: 300 dpi Printing cycle: 2.5 ms / Line Number of divided drives: 2 divided drives (maximum number of simultaneous heating elements = 1536 dots) Input power: Comparative example (thermal head 201) P = 0.120 W The present invention (thermal head 1) P = 0.120 W Here, W (Watt) ) Means the input power to the heating resistor antibodies corresponding to the first image data. Energizing pulse width: Comparative example (Thermal head 201) Tp1 / Tp2 = 746/617 μs The present invention (Thermal head 1) Tp1 / Tp2 = 829/686 μs * The energizing pulse width is when the ink temperature is 24 ° C. in the above environment. The energization 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 VT1650 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. On the surface side of the thermoplastic resin film, there is provided a layer or the like composed of trace components such as an antistatic agent and an antistick agent. Ink: Ricoh Co., Ltd., Port Ink VT-600 II (black) Printing paper: Picopy PPC paper TYPE 6200 B4 T-th chart: Printing rate 100% solid Subscanning direction length 12 mm Densitometer: Macbeth densitometer (Macbeth RD915 manufactured by Macbeth) Offset judgment: According to the company limit sample In the above confirmation test conditions, dpi is (dot / inch)
Is an abbreviation for The size of the thermal head 1 in the present invention is B4 size, and the heating element 20 in the main scanning direction S is used.
3072 groups were arranged in a line, and the size of the thermal head 201 of the comparative example was B4 size.
3072 heating elements 210 are arranged in a line in the main scanning direction S. In the energizing pulse width, Tp1 is 1 before.
The first pulse width during the line heat history control, and Tp2 represents the second pulse width. The maximum value of the in-house limit sample used for the set-off determination is 5, which indicates that the set-off increases as the numerical value increases, and conversely, the set-off decreases as the numerical value decreases.

FIG. 8 shows a main part of a plate making apparatus 10A modified for the above-mentioned confirmation test. This plate-making apparatus 10A has a
As compared with the conventional plate making apparatus 200 shown in FIG. 5, the mounting position relationship between the thermal head 1 and the platen roller 16 in the sub scanning direction F is generated from the end face 49a of the thin film substrate 49 of the thermal head 1 on the master discharge side 38. Body 2
0 to the edge on the side of the end face 49a, L = 150 μm, and the thermal head 1 and the platen roller 16
The only difference is that a group of heating elements 20 of the thermal head 1 is arranged in the nip formed by the above.

Under the above confirmation test conditions, the thermal heads 201 and 1 according to the present invention and the present invention were checked for unevenness in print image density and set-off in a plate-making printing apparatus similar to that shown in FIG. The results of the test are shown in Table 1 below.

In the thermal heads 201 and 1 according to the prior art and the present invention under the above-described confirmation test conditions, the punching energy was set to make the print image density almost the same, and the effect was confirmed. When N = 1, supply of a plate-making printing apparatus, ink, master 12 and the like,
Since there is a risk that a good result may be obtained by chance due to a variation in the way in which the printed printing paper 39 falls on the paper discharge tray 52, a confirmation test was performed with the number of repetitions N = 3. It could be confirmed. The confirmation test conditions were the same as those described above, and the average image density at 11 points measured along the main scanning direction S was almost the same. The value of the print image density unevenness was 11
This was expressed as a density difference (density unevenness) between the maximum value and the minimum value in each data when the average measurement value at the point was the same.

[0051]

[Table 1]

In the above confirmation test, the perforated state and printed image state of the thermoplastic resin film portion of the master 12 were compared when the printing rate was 100%, that is, when all the heating elements 20 in the simultaneous energizing block were energized. As a result, in the perforated state, the present invention is superior in perforation separation properties in both the main scanning direction S and the sub-scanning direction F, and as a result, set-off peculiar to the plate making printing apparatus is suppressed. Also, regarding the common drop caused by the common electrode and the like, the perforated state of the thermoplastic resin film portion of the master 12 was compared and confirmed between the comparative example and the present invention, and as a result, the present invention was almost at the position of the thermal head (heating resistor). Irrespective of this, substantially the same perforated state is obtained, and as a result of printing the master, substantially the same print image density, that is, a print image with less print image density unevenness, regardless of the position of the heating element 20 of the thermal head 1 Could be obtained. In the comparative example, the confirmation test was performed using the thermal head 201 that was reduced in size. However, in FIG. 1B, the common electrode width 216 was reduced (the thermal head 201 on the master discharge side 38). From the end face 49a of the thin film substrate 49 on the end face 49a side of the heating element 21
Although the distance L to 0 is reduced to 3.25 mm), the print image density unevenness depending on the position of the heating element 210 of the thermal head 201 as described above is slightly observed, but the level at which a problem is considered. Was not.

However, the thermal head 1 of the present invention
Level (from the end face 49a of the thin film substrate 49 to the thin film substrate 49).
L = 15 to the heating element 20 closest to the end face 49a
(0 mm), when the thermal head 201 is further reduced in size, that is, when the common electrode width 216 is further reduced, it can be easily estimated that considerable unevenness in print image density will occur. In any case, when the comparative example and the prototype of the present invention were tested for confirmation, the product of the present invention was clearly better in terms of print image density unevenness.

Next, with regard to the master shrinkage, the result 2 as shown in Table 2 below was obtained. = Confirmation test condition 2 = Basically the same as Confirmation test condition 1, except that a chart having a printing rate of 100% and a solid area of about 320 mm in the sub-scanning direction F was used. The measurement points represent the master contraction rates in the sub-scanning direction at three points (left end, center, right end in the main scanning direction S of the thermal head). However, in order to more clearly confirm the effect at the time of this confirmation test, as shown in FIG. 8, there is no front tension at the tension roller pair 17a, 17b which is considered to be effective in suppressing master shrinkage. A slight back tension that does not cause plate-making wrinkles is confirmed by applying a load by appropriately pressing the master 12 pulled out from the master roll 12A between the master receiving member 15 and the back tension roller 14 to apply a load. The test was performed. When the print image density was confirmed after this confirmation test, the print image densities were almost the same.

[0055]

[Table 2]

From the above result 2, when the number of repetitions was N = 3, the product of the comparative example was compared with the product of the present invention in terms of master shrinkage (image size reproducibility). Was reduced to about half. Thus, according to the first embodiment and its examples,
When making a master 12 using the thermal head 1 in the plate making apparatus 10 or a plate making printing apparatus equipped with the plate making apparatus 10, the power of the common electrode 21 and the like is applied to any original image. Since the loss can be minimized, the perforated state of the master that has been perforated / plated is uniform and each perforation is independent of each other. It is obtained at any location of the heating element 20 of the head 1 and forms a suitable perforated image corresponding to the resolution in the main scanning direction S and the sub-scanning direction F. It is possible to form an optimal print image with good image dimensional reproducibility and less unevenness of print image density by suppressing the That by reducing the excess transition to the printing paper of the ink can be a minimized defect that the plate making printing device-specific set-off, also the plate making apparatus 10
In addition, the life of the thermal head 1 mounted on the plate-making printing apparatus equipped with the plate-making apparatus 10 can be prolonged, and the size of the thermal head 1 mounted on the plate-making printing apparatus can be reduced for the user. Efficiency can be achieved, and the thermal head 1 itself becomes inexpensive, so that it 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 1, thereby being more environmentally friendly. It is possible to provide a plate-making apparatus 10 that can obtain many of these advantages and a plate-making printing apparatus equipped with the plate-making apparatus 10. (Modification 1) FIG. 2 shows a modification 1 of the first embodiment. The first 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. The thermal head 1A is different from the thermal head 1 in that the common electrode between every two heating elements 20 arranged continuously in the main scanning direction S is a dummy electrode 26, The only difference is that the common electrode 21 is shared by S.

Each heating element 20 of the thermal head 1A is separated in the main scanning direction S by a folded common electrode portion 21a and a dummy electrode 26. Dummy electrode 2
6 suppresses the thermal interference of the adjacent heating elements 20, and
It is provided for the purpose of making the perforated state uniform. FIG. 2 shows an electrode pattern in which one folded common electrode portion 21a is arranged corresponding to two heating elements 20 arranged continuously in the main scanning direction S.
May be more. The dummy electrode 26 can be used as a common electrode by extending the pattern in the sub-scanning direction F and connecting it to the heating power supply connector or the thermal head substrate 9 or the like. It goes without saying that the plate making apparatus 10 equipped with the thermal head 1A of the first modification and the plate making printing apparatus provided with this plate making apparatus 10 can also obtain the various advantages described in the first embodiment and its examples. (Modification 2) FIG. 3 shows a modification 2 of the first embodiment. The second modification is different from the first embodiment only in having a thermal head 1B instead of the thermal head 1 in the first embodiment. In the thermal head 1B, as compared with the thermal head 1, the common electrode between every two heating elements 20 arranged continuously in the main scanning direction S becomes the dummy electrode 26 similarly to the second modification. The only difference is that the common electrode 21 is shared corresponding to the two heating elements 20 arranged continuously in the main scanning direction S.

Each heating element 20 of the thermal head 1B is separated in the main scanning direction S by a folded common electrode portion 21a and a dummy electrode 26. FIG. 3 shows two heating elements 2 arranged continuously in the main scanning direction S.
Although the electrode pattern in which one folded common electrode portion 21a is arranged corresponding to 0 has been described, the number of the corresponding heating elements 20 may be more. As in the first modification, the dummy electrode 26 can be used as a common electrode by extending the pattern in the sub-scanning direction F and connecting it to the heating power supply connector or the thermal head substrate 9 or the like. Modification 2
It goes without saying that the plate making apparatus 10 equipped with the thermal head 1B and the plate making printing apparatus equipped with the plate making apparatus 10 can also obtain the various advantages described in the first embodiment and its examples. (Modification 3) FIG. 4 shows a modification 3 of the first embodiment. The third modification is different from the first embodiment only in that a thermal head 1C is provided instead of the thermal head 1 in the first embodiment. The thermal head 1C differs from the thermal head 1 only in that the common electrode 21 is shared in the main scanning direction S. All the heating elements 20 of the thermal head 1C are separated in the main scanning direction S by the folded common electrode portion 21a. It is needless to say that the plate making apparatus 10 equipped with the thermal head 1C of Modification 3 and the plate making and printing apparatus provided with this plate making apparatus 10 can also obtain the various advantages described in the first embodiment and its examples.

The above-described plate-making printing apparatus has been a so-called single-sided printing method for printing on one side of printing paper. In recent years, a plate-making printing apparatus of a so-called double-sided simultaneous printing method for simultaneously printing on both sides of printing paper has been developed. Various proposals have been made. As an example of such a simultaneous double-sided printing method, see, for example,
No. 71996, JP-A-9-234941, and JP-A-11-1057. 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 them. It will be apparent to those skilled in the art that various embodiments and examples can be configured within the scope of the present invention according to the necessity and use thereof.

[0061]

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, the common electrode connected to one end of each heating element of the thermal head on the sub-scanning direction and disposed on the thin film substrate on the heat-sensitive master discharge side is connected to the heat-sensitive master discharge side. By folding back to the opposite side and arranging it between the adjacent heating elements, the energy loss of the common electrode due to the difference in the location of the heating elements in the thermal head is not affected by any original image to be made. In a state where the influence is considerably reduced, the thermoplastic resin film portion of the heat-sensitive master is hot-melted by the Joule heat generated by the heating element, and the punching and plate making is performed. It is possible to obtain an optimum drilling state that is uniform and independent of each other at any of the locations where the heating elements are arranged. It can be favorable image size reproducibility by can be suppressed. As a result, it is possible to make the print image density uniform and to contribute to forming an optimum print image with less print image density unevenness, and at the same time, to reduce excessive transfer of ink used in the plate-making printing apparatus to the printing paper. Thereby, it is possible to contribute to the reduction of the problem of set-off which is 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, which is inexpensive for the user and can be reflected in the price of the product. The amount of materials used can be reduced along with the development, so that more environmentally friendly materials can be provided.

According to the second aspect of the present invention, the common electrode between at least two heating elements arranged continuously in the main scanning direction is a dummy electrode. In addition to the effect of the above, the amount of material used for the common electrode can be reduced, so that it becomes more inexpensive for the user and can be reflected in the price of the product,
As the amount of material used for the common electrode can be reduced, a more environmentally friendly material can be provided.

According to the third aspect of the present invention, the length of each heating element in the sub-scanning direction is equal to or shorter than the length of each heating element in the main scanning direction. In addition to the effects of the present invention, in the case where the thermoplastic resin film portion of the heat-sensitive master is hot-melted by Joule heat at any resolution and subjected to perforation and plate making, it is excellent in heat concentration, and when continuous printing and plate making are performed. Effect of heat storage (deterioration of perforation separation in the sub-scanning direction due to application of excess energy due to heat storage)
Can be suppressed, the master contraction peculiar to the plate making apparatus can be suppressed, and the thermal stress can be reduced by suppressing the heat generation peak temperature to the minimum necessary, thereby extending the life of the thermal head. Further, the separation of the perforated state in the main scanning direction and the sub-scanning direction can be ensured, and an independent perforated state can be obtained. This is also effective in reducing set-off peculiar to a plate making printing apparatus.

According to the fourth 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 3 can be obtained at any temperature of the thermal head.

According to the fifth 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 described in any one of claims 1 to 4 can be obtained in any original image, that is, in the printing rate.

According to a sixth aspect of the present invention, there is provided a plate cylinder comprising the plate-making apparatus according to any one of the first to fifth aspects, wherein the master made by the plate-making apparatus is wound around the outer peripheral surface of the plate cylinder. 6. A plate-making printing apparatus comprising: an ink supply means for supplying ink to a master on the plate cylinder; and a printing press for printing on the printing paper by pressing the printing paper against the master on the plate cylinder. In addition to the effects of the invention described in any one of the above, the printing image density can be made uniform to form an optimum printing image with less printing image density unevenness, and at the same time, ink printing paper used in a plate making printing apparatus The problem of set-off, which is peculiar to a plate making printing apparatus, can be reduced by reducing the excessive transfer to the printing plate.

According to the seventh aspect of the present invention, the perforation energy adjusting means for each ink temperature adjusts the perforation energy supplied to the heating element of the thermal head in accordance with the ink temperature detected by the ink temperature detecting means. By adjusting the energy for perforation, the effect of the invention described in claim 6 is exerted at any temperature of the ink.

[Brief description of the drawings]

FIG. 1A is an enlarged plan view of the vicinity of a heating element of a thermal head and around a common electrode and a lead electrode according to a first embodiment of the present invention, and FIG. It is an enlarged plan view around a common electrode and a lead electrode.

FIG. 2 is an enlarged plan view of the vicinity of a heating element of a thermal head and around a common electrode and a lead electrode according to a first modification of the first embodiment.

FIG. 3 is an enlarged plan view of the vicinity of a heating element, a common electrode, and a periphery of a lead electrode of a thermal head according to a second modification of the first embodiment.

FIG. 4 is an enlarged plan view of the vicinity of a heating element of a thermal head and around a common electrode and a lead electrode according to a third modification of the first embodiment.

FIG. 5 is a control block diagram of a plate making apparatus and a plate making printing apparatus to which the present invention is applied.

FIG. 6 is a side view of a main part showing an arrangement position of a thermistor for detecting a temperature of the thermal head.

FIG. 7 is a side view of a main part for explaining a position where a heating element is arranged from an end surface of the thin film substrate of the thermal head in the first embodiment and the like.

FIG. 8 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. 9 is a cross-sectional view of a main part showing a cross-sectional structure of a thermal head according to the related art and the first embodiment and the like.

FIG. 10 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, 1C Thermal head 6 Thermal head temperature perforation energy adjusting means,
Microprocessor as perforation energy adjusting means according to duty ratio, perforating energy adjusting means according to ink temperature, means for counting the number of energization 8 Thermistor as thermal head temperature detecting means 10 Plate making device 20 Heating element 21 Common electrode 21a Folded common electrode section 23 Main scanning Resolution pitch 24 Sub-scanning resolution pitch 27 Length in the main scanning direction as the length of the heating element in the main scanning direction 28 Length in the sub-scanning direction as the length of the heating element in the sub-scanning direction F Sub-scanning direction S Main scanning direction

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Yoshiyuki Shishido, inventor, Tohoku Ricoh Co., Ltd. 1 at Shinmei-do, 3rd, Nakamei, Shimada-cho, Shibata-cho, Miyagi Prefecture (72) Inventor, Yasunori Kidoura, Shibata-cho, Shibata-gun, Miyagi No. 3 of the name of the middle name Shinmei-do 1. F-term in Tohoku Ricoh Co., Ltd. (reference) 2H084 AA13 AA38 AE01 AE05 AE08 CC09

Claims (7)

[Claims] 1. A thermal head having a plurality of heating elements arranged in a main scanning direction on a thin film substrate is brought into contact with a thermosensitive master having a thermoplastic resin film, and the thermal head is contacted with the thermal head. A plate making apparatus for making a plate while relatively moving the susceptibility master in a sub-scanning direction orthogonal to the main scanning direction. The plate-making apparatus is connected to one end of each of the heating elements on the side of the sub-scanning direction, and A plate making apparatus, wherein a common electrode disposed on a thin film substrate is folded back to the side opposite to the heat-sensitive master discharge side and disposed between the adjacent heating elements. 2. The plate-making apparatus according to claim 1, wherein the common electrode between at least two heating elements arranged continuously in the main scanning direction is a dummy electrode. Plate making equipment. 3. The plate making apparatus according to claim 1, wherein the length of each heating element in the sub-scanning direction is equal to or shorter than the length of each heating element in the main scanning direction. Plate making equipment. 4. A plate making apparatus according to claim 1, further comprising a thermal head temperature detecting means for detecting a temperature of said thermal head, wherein said thermal head temperature detecting means detects a temperature of said thermal head. A plate making apparatus comprising: a thermal head temperature-specific perforation energy adjusting means for adjusting perforation energy supplied to the heating element of the thermal head to predetermined perforation energy. 5. The plate making apparatus according to claim 1, further comprising: a current supply number counting means for counting the number of current supply actually supplied to each of said heating elements; A plate making apparatus comprising: a perforation rate-dependent perforation energy adjusting means for adjusting perforation energy supplied to the heating element of the thermal head to predetermined perforation energy in accordance with the counted energization number. 6. 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 means for supplying ink to the plate cylinder, wherein the printing paper is pressed against the master on the plate cylinder to perform printing on the printing paper. 7. The plate-making printing apparatus according to claim 6, further comprising ink temperature detecting means for detecting the 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: a perforation energy adjusting means for adjusting ink temperature to a perforation energy supplied to a heating element to a predetermined perforation energy.