JP2001080026A - Plate making apparatus and plate making printing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plate making apparatus of good image dimension reproducibility which is free from the generation of wrinkles, etc., in a master during plate making even when a master of a thin porous support, a master without a porous support, as well as a conventional master are used. SOLUTION: In a plate making apparatus 39 having a master supporting member 8c, a thermal head 11, and a platen roller 10, a back tension applying means 36 for applying back tension F1 to a master 8 located on the upstream side in the master conveyance direction X of the platen roller 10 and a front tension applying means 38 for applying front tension F2 to the master 8 located on the downstream side in the master conveyance direction of the plated roller 10 are provided so that the back tension is made greater than the front tension F2.

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 printing apparatus, and more particularly, to a plate-making apparatus having a thermal head for heating and making a plate, a platen roller for conveying a master while pressing the master, and this plate-making apparatus. The present invention relates to a stencil printing apparatus provided with the apparatus.

[0002]

2. Description of the Related Art Conventionally, stencil printing using a digital thermosensitive stencil printing apparatus has been known as a simpler printing method. In this method, a thermal head in which fine heating elements are arranged in a line is pressed against a platen roller via a master (hereinafter simply referred to as a "master"), and the heating elements of the thermal head are pulsed to generate heat while generating heat. After the master is conveyed, it is heated and melt-punched and made based on the image information.Then, the master is automatically conveyed and automatically wound around the outer peripheral surface of the porous cylindrical plate cylinder. The printing paper is continuously pressed by a pressing means such as a press roller, and ink is supplied by an ink supply member provided inside the plate cylinder, and the ink passes through the opening portion of the plate cylinder and the perforated portion of the master to form a printing paper. Is transferred to form a printed image. The master used in such a conventional stencil printing machine includes a very thin thermoplastic resin film such as polyester (hereinafter, simply referred to as a "film") and a paper support such as Japanese paper or synthetic fiber as an ink-permeable porous support. Or it has a laminated structure that is laminated with a mixture of Japanese paper and synthetic fibers,
The ink exuded from the fiber portion of the porous support and the perforated portion of the film is transferred to printing paper and stencil printing is performed.

[0003] For this reason, the passage of ink is hindered in a portion called lumps where fibers used for the porous support of the master are complicatedly entangled and solidified, or in a portion where thick fibers cross the perforated portion of the film. The ink does not transfer to the printing paper, and a fiber pattern appears, especially in a solid portion, or characters or fine lines are blurred or cut off. There was a defect. Therefore, the thickness of a porous support such as Japanese paper, which is the basis of the fiber, is reduced, or printing is performed using a master substantially made of only a thermoplastic resin film from which the porous support itself has been removed. Attempts have been made to reduce the number of fibers. While the thickness of a conventional master is usually about 40 to 50 μm, the thickness of a master substantially consisting of only a thermoplastic resin film is extremely thin, about 1 to 2 μm. Has become.

[0004]

However, the strength of the master is greatly reduced by reducing the thickness of the porous support of the master or by removing the porous support itself. In the conventional master, the strength was secured by Japanese paper etc. as a porous support, so that master expansion during plate making and deformation of the master due to shrinkage of the film were prevented, but the thickness of the porous support was When the thickness is thin or there is no porous support at all, the strength is greatly reduced and the master elongation and the film shrinkage are likely to be uneven, which causes wrinkles at the time of master making,
There has been a problem in that when the master is wound around the plate cylinder, the wrinkles of the master are likely to occur due to the deformation of the master. The film surface of the master is subjected to anti-sticking treatment by applying an anti-stick agent or the like to reduce the contact resistance generated between the master conveyed by the platen roller and the thermal head during plate making to reduce the master resistance. Although the feeding of the master is not uneven, the part where the film is heated and melted and the perforation and plate making is performed, because the resin part is exposed and the effect of the stick preventive agent is reduced, The contact resistance increases, and the transport delay of the master is likely to occur, albeit slightly. If the transfer distance of the master is different due to such a transfer delay of the master, the reproducibility of the image dimension is deteriorated, and the transfer delay of the plate making portion tends to loosen the master on the platen roller on the upstream side in the master transfer direction. However, there is a problem that the slack of the master is crushed by the platen roller and wrinkles are generated.

In the case of a master in which film deformation is prevented by a porous support like a conventional master, the master is transported by a transport member such as a pair of transport rollers provided downstream of the platen roller in the master transport direction. By pulling the master on the downstream side in the transport direction and applying front tension, it is possible to compensate for the transport delay of the master, but the master is not made on a master with a thin porous support or a master without a porous support Because the strength of the perforated and plate-making part is significantly lower than the part, if the front tension is applied too much, the perforated part with reduced strength will grow,
Conversely, if the front tension is weak, the master shrinks and deforms easily, and the winding of the master on the plate cylinder tends to cause winding wrinkles. Was. The master made between the platen roller and the thermal head is in a state where the strength of the portion is reduced, but in a case where the master in the portion is subsequently conveyed in a state of approaching the thermal head. However, if plate making is continued continuously at the beginning, there is also a problem that the plate portion of the plate made by the plate making is easily deformed due to the heat storage of the thermal head and the like. .

Accordingly, the present invention has been developed to solve the above-mentioned problems, not only for a conventional master but also for a master having a thin porous support or a master consisting essentially of a thermoplastic resin film, for example. Even when a master without a porous support is used, no wrinkles or the like of the master are generated at the time of plate making. An object of the present invention is to provide a stencil printing apparatus having good image size reproducibility.

[0007]

According to the first aspect of the present invention,
Master storage means for storing a master so as to be able to be fed out, a thermal head for heating and making a master according to image information, and a rotatable platen roller for moving the master downstream in the master transport direction while pressing the master against the thermal head And a back tension applying means for applying a back tension to the master upstream of the platen roller in the master transport direction, and a front tension of the master downstream of the platen roller in the master transport direction. And a front tension applying means for applying the back tension, wherein the back tension is made larger than the front tension.

According to a second aspect of the present invention, in the plate making apparatus according to the first aspect, the back tension applying means is provided between the master storage means and the platen roller, and is provided on the upstream side in the master transport direction. It is characterized by comprising a tension roller rotatable in contact with the master and braking means for braking the rotation of the tension roller.

As a specific example of the tension roller, a pair of tension rollers used in an embodiment described later is preferable in terms of stably applying the back tension in the master width direction. The present invention is not limited to this as long as no special advantage is required. For example, a combination of one tension roller for pressing the master against the plate member and the above plate member may be used. As a specific example of the braking means, it is used for relatively small tension control in terms of controlling the braking force by electrically varying the transmission torque or variably controlling the braking force according to the type of master. A powder type or hysteresis type electromagnetic brake as described above is preferably used. If such an advantage is not required, the present invention is not limited to this, and may be, for example, a friction type electromagnetic brake or a mechanical brake means. Therefore, the back tension applying means in claim 1 is
For example, a configuration in which the back tension is applied to the master by the weight of the tension roller is also included.

[0010] According to a third aspect of the present invention, in the plate making apparatus of the first aspect, the front tension applying means comprises:
A rotatable transport roller that is disposed downstream of the master transport direction and contacts the master downstream of the master transport direction and moves the master downstream of the master transport direction; It is characterized by comprising a transport roller driving means for rotating at a peripheral speed higher than the speed, and a torque limiter provided between the transport roller and the transport roller driving means.

As a specific example of the transport roller, a pair of transport rollers used in an embodiment described later is preferable from the viewpoint of stably applying the front tension in the master width direction. The present invention is not limited to this as long as no special advantage is required. For example, a combination of one transport roller for pressing the master against the plate member and the plate member may be used. As a specific example of the transport roller driving unit, a stepping motor used in an embodiment described later is preferable from the viewpoint that the rotation speed control is performed stably and easily, but such an advantage may not be desired. Is not limited to this, the DC for control
It may be a motor.

As a specific example of the torque limiter, a powder type or hysteresis type electromagnetic clutch, which is used for relatively small tension control, is preferably used in terms of electrically transmitting torque to control front tension. Can be If such an advantage is not required, the present invention is not limited to this, and may be, for example, a friction type electromagnetic clutch or a mechanical type torque limiter. For this reason, the front tension applying means in claim 1 is configured such that the master is moved and conveyed by a conveying roller or the like while applying front tension to the master by its own weight of a tension roller capable of moving up and down and rolling freely. And so on.

The invention described in claim 4 is the first or third invention.
In the plate making apparatus described above, based on a signal from the characteristic value detecting means for detecting a characteristic value of a master expansion-related factor affecting expansion and contraction of a master plate making dimension during plate making, Control means for controlling the front tension applying means so as to change the magnitude of the tension.

According to a fifth aspect of the present invention, in the plate making apparatus according to the fourth aspect, the characteristic of the master expansion / contraction-related factor is an amount of a plate-making image formed on a master, and the characteristic value detecting means includes: It is characterized by comprising image amount detecting means for detecting the amount.

According to a sixth aspect of the present invention, in the plate making apparatus of the fourth aspect, the characteristic of the master expansion / contraction-related factor is at least one of an internal temperature and an external temperature of the plate making apparatus main body. The characteristic value detecting means comprises a temperature detecting means for detecting at least one of the temperatures.

According to a seventh aspect of the present invention, in the plate making apparatus according to the fourth aspect, the characteristic of the master expansion / contraction-related factor is at least one of humidity inside and outside the main body of the plate making apparatus. The characteristic value detecting means comprises a humidity detecting means for detecting at least one of the humidity.

The invention according to claim 8 is the invention according to claims 4, 5, and 6.
Or the plate making apparatus according to 7, wherein the control means controls the front tension applying means to change the magnitude of the front tension based on each signal from at least two or more characteristic value detecting means. It is characterized by.

According to a ninth aspect of the present invention, in the plate making apparatus of the second aspect, the braking means can change its braking force in accordance with the type of master.

According to a tenth aspect of the present invention, in the plate making apparatus according to any one of the first to ninth aspects, a master type detecting means for detecting the type of the master, and a signal from the master type detecting means. A stencil making operation control means for inhibiting a stencil making operation when the master is different from a master set to be used in advance.

According to an eleventh aspect of the present invention, in the plate making apparatus according to the tenth aspect, a deflection detecting means for detecting deflection of a master formed in a predetermined size, and sucks and temporarily stores the deflection of the master. And a deflecting suction time measuring means for measuring a time when the deflecting of the master is sucked by the suction storing means based on a signal from the deflecting detecting means.

According to a twelfth aspect of the present invention, in the plate making apparatus according to any one of the first to eleventh aspects, the master downstream of the platen roller in the master transport direction or the master made in the master conveying direction is connected to the thermal transfer master. It is characterized in that it is conveyed in a direction away from the head.

According to a thirteenth aspect of the present invention, there is provided a plate cylinder having the above-described plate-making apparatus according to any one of the first to twelfth aspects, and a plate cylinder for winding a master made by the plate-making apparatus. Having ink supply means for supplying ink to the upper master,
A plate-making printing apparatus characterized in that printing is performed on a printing sheet by pressing the printing sheet against a master on the plate cylinder.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention including embodiments with reference to the drawings (hereinafter, simply referred to as "embodiments").
Will be described. In the embodiments and the like, members, components, and the like having the same function, shape, and the like are denoted by the same reference numerals, and description thereof will be omitted as much as possible. In the figures, members and components that are configured as a pair and need not be specifically distinguished and described are described in order to simplify the description.
By appropriately describing one of them, the description will be replaced. For the sake of simplicity of the drawings and the description, even if the members and the components are to be shown in the drawings, the members and the components that do not need to be specifically described in the drawings may be omitted as appropriate.

In FIGS. 1 and 2, reference numeral 39 denotes a plate making apparatus, and reference numeral 60 denotes a plate making and printing apparatus provided with the plate making apparatus 39. The plate making device 39 includes a master supporting member 8c as a master storage unit that stores the master 8 so as to be able to be fed in the master transport direction X, a thermal head 11 that heats and makes the master 8 that has been fed in accordance with image information, and a thermal head. A platen roller 10 that moves and conveys the master 8 downstream in the master conveyance direction X while pressing the master 8 against the master 11;
Back tension applying means 36 for applying the back tension F1 to the upstream master 8; and front tension applying means 38 for applying the front tension F2 to the master 8 downstream of the platen roller 10 in the master transport direction X. Is provided.

The master 8 has a continuous sheet shape and is wound around a roll core 8b made of a synthetic resin.
Is formed. The roll core 8b protrudes from both end surfaces of the master roll 8a and is formed to be longer than the width of the master 8. The master roll 8a is detachable from the master support member 8c because the roll cores 8b at both ends are rotatably supported in the counterclockwise direction by the master support member 8c. Master support member 8c at both ends
Are attached to a pair of plate making side plates (not shown) arranged on both left and right sides of the plate making device 39 along the master transport direction X. Therefore, the master 8 is stored by the master supporting member 8c so as to be able to be fed in the master transport direction X from the master roll 8a. Master 8
For example, it consists essentially of a thermoplastic resin film having a thickness of 1 to 3 μm. Here, the master substantially consisting only of the thermoplastic resin film means, in addition to the master consisting of only the thermoplastic resin film, the master containing a trace component such as an antistatic agent in the thermoplastic resin film, The film includes one or more thin film layers such as an overcoat layer formed on both main surfaces of the thermoplastic resin film, that is, at least one of the front surface and the back surface.

The back tension applying means 36 is disposed between the master supporting member 8c and the platen roller 10,
A pair of upper and lower rotatable tension rollers 9b, 9a rotatably contacting and nipping the master 8 upstream of the platen roller 10 in the master transport direction X, and an electromagnetic as braking means for braking the rotation of the tension roller lower 9a. Brake 3
7

The lower part of the tension roller 9a is made of an elastic body having conductivity at its outer periphery, and is formed integrally with a metal shaft. The lower tension roller 9a is rotatable in a counterclockwise direction because both ends of the shaft are rotatably supported by the pair of plate-making side plates. As the electromagnetic brake 37, the lower part of the tension roller 9 is used.
A powder-type electromagnetic brake provided at the shaft end of a is preferably used. The powder-type electromagnetic brake 37 applies a braking force set in advance to the lower tension roller 9a via the shaft according to the type of the master, so that the master 8 on the upstream side of the platen roller 10 in the master transport direction X is moved. That is, it has a function of applying a back tension F1 of a predetermined size to the master 8 between the platen roller 10 and the tension roller upper / lower pair 9b, 9a. More specifically, the back tension F1 having a size set in advance according to the type of the master generates an exciting current flowing through the exciting coil of the powder type electromagnetic brake 37 in response to a command from the control device 50 shown in FIG. By varying the transmission torque, the transmission torque is variably controlled substantially in proportion thereto, so that a braking force (braking force) of a magnitude set in advance according to the type of the master is transmitted through the shaft to the lower portion of the tension roller. 9a. The electromagnetic brake 37 is not limited to a powder-type electromagnetic brake, and a hysteresis-type electromagnetic brake, for example, is preferably used for relatively small tension control.

The upper tension roller 9b is made of metal and has a shaft formed integrally therewith. The upper tension roller 9b is rotatable clockwise because both ends of the shaft are rotatably supported by the pair of plate-making side plates.

The back tension F1 applied to the master 8 between the platen roller 10 and the tension roller upper / lower pair 9b, 9a is the same as the thermal head 1 during plate making.
Master 8 at nip portion between platen 1 and platen roller 10
The non-perforated portion is quickly fed due to the conveyance / contact resistance of the perforated portion, causing the master 8 to be loosened, or the non-perforated portion of the master 8 is pulled by the conveying rollers 12a and 12b, which will be described later. The back tension is set to a large / high back tension F1 such that the platen roller 10 is slightly slipped with the master 8 so that uneven conveyance is not caused so as not to be promoted. The tension roller upper and lower pairs 9b and 9a are pressed against each other by being given an appropriate pressing force by a biasing means such as a spring. The upper and lower pairs of tension rollers 9b and 9a
In the case of the conveyance at the time of the initial setting, the driving force is transmitted from a driving source (not shown) to carry the rotation. The upper and lower pairs of tension rollers 9b and 9a are sent to the master 8 by the control device 50 described later when the master 8 is quickly sent out of the plate-making area or when the image is skipped during the plate-making operation. In order to reduce the load on the vehicle, the braking force is not reduced, and the back tension is not applied.

The platen roller 10 is arranged downstream of the tension roller upper and lower pairs 9b and 9a in the master transport direction X, and is formed integrally with the platen roller shaft via a metal core. ing. For example, the platen roller 10 is formed by covering the outer periphery of the metal core of the platen roller 10 with a silicone rubber layer having good non-adhesiveness to the master 8, heat resistance, conductivity and good compression set. Have been. The platen roller 10 is rotatable clockwise because both ends of the platen roller shaft are rotatably supported by the pair of plate-making side plates. The platen roller 10 is connected to a stepping motor 35 as platen roller driving means via a rotation transmitting member (not shown) such as a timing belt and a gear.
Thereby, it is driven to rotate clockwise. As described above, the platen roller 10 has the stepping motor 35
As a result, the master 8 is pulled out from the master roll 8a while receiving the back tension F1 by the tension roller upper and lower pairs 9b and 9a.

The stepping motor 35 includes a controller 50
In response to a command from the printer, the amount of punching (perforation rate) perforated in accordance with the original image by the scanner 47 shown in FIG. 2 provided in an original reading device (not shown) disposed above the plate making device 39 is determined. In the case where a plate is read and the plate making portion is large, that is, a plate making a solid image or the like in which the amount of the plate making image is large and the master conveyance load is increased, the punching ratio and the like with respect to the size of the document detected by the image amount detecting means 48 are compared. Then, when it is determined that the perforation amount is large, the rotational speed (peripheral speed) of the platen roller 10 is increased to correct a dimensional change of the plate-making image due to slight slippage occurring between the platen roller 10 and the master 8. It has become.

The thermal head 11 is a platen roller 1
The platen roller 10 extends in parallel with the platen roller shaft 0 and is freely movable toward and away from the platen roller 10 via the master 8 by a contacting / separating mechanism including a cam, a spring member, and the like (not shown). The thermal head 11 is urged by the spring member in a direction in which the thermal head 11 comes into contact with the platen roller 10. In the main scanning direction of the thermal head 11, a large number of heating elements (not shown) are disposed at a position where the heating element contacts the platen roller 10 via the master 8. The thermal head 11 selectively heats the heating element based on a digital image signal processed and transmitted by an A / D converter and a plate making control device (both not shown) of a document reading device (not shown), The master 8 has a well-known function as a plate making means for selectively heating and melting perforation and plate making.

The front tension applying means 38 is disposed on the downstream side in the master transport direction X adjacent to the platen roller 10, and is disposed in the master transport direction X with respect to the platen roller 10.
A pair of upper and lower transport rollers 12a and 12b serving as rotatable transport rollers for moving and transporting the master 8 downstream in the master transport direction X by contacting and nipping the master 8 on the downstream side and an upper transport roller 12a Motor 35 serving as a transport roller driving means for rotating the roller at a peripheral speed (transport speed) higher than the peripheral speed (transport speed) of the platen roller 10;
And a first electromagnetic clutch 33 having a function as a torque limiter for adjusting the front tension F2 to a preset value. Inside the transport roller 12
a is connected to a stepping motor 35 via a rotation transmission member (not shown) such as a plurality of gears, and is thereby driven to rotate clockwise. Platen roller 10 and conveyance roller 12a via stepping motor 35
The surrounding drive system is, for example, disclosed in
The same mechanism as the rotation transmission mechanism shown in FIG. 2 of 1-77949 is adopted.

The outer periphery of each of the transport roller middle pairs 12a and 12b is made of silicone rubber, and is formed integrally with a metal shaft. The transport roller middle pair 12a, 12b
Appropriate pressing force is applied by a biasing means such as a spring to provide pressure contact. Both ends of each shaft are rotatably supported by the pair of plate-making side plates so that they can rotate in opposite directions. It has become. As the first electromagnetic clutch 33, a powder-type electromagnetic clutch provided at the shaft end of the transport roller 12a is preferably used. The first electromagnetic clutch 33 made of a powder type electromagnetic clutch applies a predetermined front tension F2 between the platen roller 10 and the transport roller so as not to forcibly pull the master 8 from the nip portion between the platen roller 10 and the thermal head 11. It has a function of giving to the master 8 between the pair 12a and 12b. The front tension F2 is set smaller than the back tension F1 described above, in other words, the back tension F1 is set larger than the front tension F2. The size of the front tension F2 is, for example, such that the platen roller 10 in a state where the connection with the stepping motor 35 is released and the stationary state of the platen roller 10 is not rotated is described. For example, F2 is set to about 0.3 kgf ≒ 2.94 N. More specifically, the provision of the front tension F2 of a preset size to the master 8 is as follows.
By changing the exciting current flowing through the exciting coil of the powder-type electromagnetic clutch according to a command from the control device 50 shown in FIG. 2, the transmission torque is variably controlled substantially in proportion thereto. The first electromagnetic clutch 33 is not limited to the powder-type electromagnetic clutch, and a hysteresis-type electromagnetic clutch, for example, is preferably used for controlling a relatively small tension.

On the downstream side in the master transport direction X adjacent to the middle pair of transport rollers 12a and 12b, a fixed blade 13 for cutting the master 8 made into plate or the master 8 not made into plate into a predetermined length.
and a guillotine type cutter 13 having a movable blade 13a and a movable blade 13a. The cutter 13 is not limited to the guillotine type, and a rotary blade moving type in which the movable blade moves while rotating in the master width direction orthogonal to the master transport direction X is also used.

On the downstream side of the master transport direction X adjacent to the cutter 13, the pair of transport rollers 12 a and 12 b and the pair of reverse rollers 1
A master stock means including a suction box 17, an opening / closing plate 16, a suction fan 18, and the like provided below the master transport path between the master conveyance path 4a and 14b. The suction box 17 is fixed between the plate making side plate pair,
It is formed with a space defined so as to form a substantially L-shape toward the upstream side of the master transport path. Suction box 1
Reference numeral 7 has a function as suction storage means for sucking and temporarily storing the deflection 8A of the master 8.

The opening / closing plate 16 is pivotally supported by the plate making side plate pair near the suction port formed at the uppermost part of the suction box 17.
An opening / closing plate driving means having a motor or a solenoid (not shown) and a driving force transmitting member such as a sector gear for transmitting the driving force from the opening / closing plate driving means to the opening / closing plate 16 can be opened and closed with respect to the suction port. ing. Opening / closing plate 1
Reference numeral 6 denotes a guide transfer position lying just below the master transfer path for transferring and guiding the master 8 as shown by a solid line in FIGS. 1, 2 and 4, and a virtual transfer position in FIGS. 1, 2 and 4. As shown by the line, the guide 8 is rotatable and displaceable about 90 degrees downward from the guide transport position and between the guide transfer position and the deflection suction position where the master 8 is stored. When the opening / closing plate 16 occupies the deflection suction position, the upper part of the suction box 17 is opened, and the above-mentioned suction port for introducing the stencil master 8 is formed above the suction box 17.

On the back side of the suction box 17 located on the downstream side of the master transport path, provided between the suction port formed of a slit or a mesh-like small hole and the exhaust port, the master 8 having made the plate is sucked. A suction fan 18 is provided. Due to the rotation of a suction fan motor (not shown) connected to the suction fan 18, the suction fan 18 is rotated to generate an air flow that flows from left to right in FIGS. While being stored in the suction box 17.

The opening / closing plate 16 is driven by the opening / closing plate driving means after the master is cut after the plate making operation is completed.
Rotation from the deflection suction position via the driving force transmission member
By displacing and occupying the guide transport position, the guide of the master 8 is guided so that the distal end of the master 8 is transported to the plate making standby position shown in FIG. 1 and the like without dropping the distal end of the master 8 from the suction port into the suction box 17. It is supposed to. Further, the opening / closing plate 16 occupies the guide conveyance position after the master is cut after the plate making operation is completed, and then the opening / closing plate driving means is driven in the opposite direction to the above, so that the leading end of the master 8 is turned to the reversing roller pair. After being held between the nip portions 14a and 14b and reaching the plate making standby position, the plate is rotated and displaced again to the deflection suction position.

4 above the suction port of the suction box 17.
As shown in FIG. 3, the deflection 8A of the master 8 having a predetermined size having an upwardly convex shape in the master 8 having been made.
Detection sensor 1 as deflection detection means for detecting
9 are provided. The master detection sensor 19 includes, for example, a reflection type photo interrupter.

Downstream of the suction box 17 and the master detection sensor 19 in the master conveyance direction X, a pair of rotatable upper and lower reversing rollers 14a and 14b for conveying the master 8 are provided.
Are arranged. Each of the reversing roller pairs 14a and 14b has an outer peripheral portion made of silicone rubber, and is formed integrally with a metal shaft. Reverse roller pair 14a, 14b
Are provided with an appropriate pressing force by a biasing means such as a spring and are pressed against each other, and both ends of each of the shafts are rotatably supported by the plate-making side plate pair so that they are in opposite directions to each other. It is rotatable. Reversing roller pair 14a,
14b is the master 8 from the suction port of the suction box 17
Is slightly inclined in the counterclockwise direction, which is the direction in which The reversing roller 14a is connected to a stepping motor 35 via a plurality of gears or a rotation transmission member (not shown) such as a belt, and thereby is driven to rotate clockwise.

The reversing roller pair 14a, 14b is set to rotate at a peripheral speed (transport speed) higher than the peripheral speed (transport speed) of the platen roller 10 by the rotation transmitting member including the stepping motor 35. The master 8 is given an appropriate front tension while sliding with the master 8. Reversing roller 14a
A second electromagnetic clutch 34 for connecting and disconnecting the rotational driving force of the stepping motor 35 to the reversing roller 14a is provided at the end of the shaft. The second electromagnetic clutch 34 includes, for example, a powder type electromagnetic clutch or a hysteresis type electromagnetic clutch. Note that, instead of the second electromagnetic clutch 34, a single stepping motor independent of the stepping motor 35 may be driven alone.

Downstream of the pair of reversing rollers 14a and 14b in the master transport direction X, a guide plate 15 for guiding the master 8 having been made or a tip of the master 8 to a clamper 7 provided on the plate cylinder 1 is provided. It is provided to extend in each axial direction of the pair of reversing rollers 14a, 14b. The plate making device 39 includes a platen roller 10 and a transport roller middle pair 12 disposed between the plate making side plate pair, which is a plate making device main body.
A temperature sensor 30 as temperature detecting means for detecting temperatures near a and 12b and a humidity sensor 31 as humidity detecting means for detecting humidity at the same site are provided. As the temperature sensor 30, a thermistor or the like is preferably used. These temperature sensor 30 and humidity sensor 31
Constitutes a characteristic value detecting means group for detecting a characteristic value of a master expansion / contraction-related factor which affects expansion / contraction of a master plate making dimension at the time of plate making, together with an image amount detecting means 48 described later. As the characteristics of the master expansion / contraction related factors, at least the following four can be empirically listed as the main ones. That is, the characteristic of the master expansion / contraction-related factor is the amount of plate making image formed on the master, the characteristic of the master expansion / contraction-related factor is the temperature inside the main body of the plate making device 39, and the characteristic of the master expansion / contraction-related factor is Internal humidity, which is the type of master corresponding to the strength of the master. In the present embodiment, the temperature sensor 30 and the humidity sensor 31 are arranged inside the plate making apparatus main body in order to grasp the temperature and the humidity as the actual environmental state as accurately as possible. If it is not possible to place the plate making device inside the plate making device main body due to restrictions on the layout of the plate making device main body, the outer wall of the main body panel outside the plate making device main body or the installation part of the plate making printing device 60 to detect the temperature and humidity around the outside of the plate making device main body. May be arranged in the vicinity. That is, the temperature detecting means and the humidity detecting means may be provided so as to detect at least one of the temperature and the humidity inside and outside the plate making apparatus main body.

On the left side of the plate making apparatus 39 in FIG. 1, a porous cylindrical support cylinder, and a mesh screen (made of resin or metal mesh) wound in a plurality of layers so as to cover the outer periphery of the support cylinder. (Not shown)) is provided. The plate cylinder 1 has an opening 1a (printable area) having a large number of ink-permeable openings,
It has a well-known configuration including a non-opening (non-printable area) provided with a clamper 7 and the like. The plate cylinder 1 is wound around and fixed to an outer peripheral portion of an end plate flange (not shown), and is rotatably supported around a support shaft also serving as an ink pipe 5 described later. The plate cylinder 1 is rotated in a direction indicated by an arrow (clockwise) in the figure by transmitting the rotational driving force of the electric motor by a drive transmitting means such as a gear or a belt connected to an electric motor (not shown).

Inside the plate cylinder 1, a rotational driving force of the electric motor is transmitted by a drive transmitting means such as a gear (not shown) so as to be rotatably supported by a side plate (not shown). An ink roller 2 that is driven to rotate in the direction of an arrow (clockwise) in the figure and supplies ink by contacting the inner peripheral surface of the plate cylinder 1 is arranged in parallel with a small gap from the ink roller 2. A doctor roller 3 that forms a wedge-shaped ink pool 4 between the roller 2 and an ink pipe 5 that supplies ink to the ink pool 4 is disposed. Note that the ink roller 2, the doctor roller 3, and the ink pipe 5 constitute ink supply means. The ink in the ink reservoir 4 is sucked from an ink pack (not shown) provided outside the plate cylinder 1 and supplied from a supply hole of an ink pipe 5.

On a part of the outer peripheral surface of the non-opening portion of the plate cylinder 1, a ferromagnetic stage 6 provided along one generatrix of the plate cylinder 1, and provided on both side ends of the stage 6. And a clamper 7 having a rubber magnet that is rotatably mounted on the clamper shaft and that can be opened and closed with respect to the plane portion of the stage 6. The clamper 7 is opened and closed at a predetermined position by an opening and closing device (not shown). Plate cylinder 1
Is stopped in a state in which the clamper 7 is located substantially on the right side as shown in FIG. 1, that is, at the plate feeding position.
The plate cylinder 1 is configured as a plate cylinder unit integrally formed with the ink pack and the like, and can be inserted into and removed from the body frame of the plate making and printing apparatus 60 in the axial direction of the ink pipe 5.

In the vicinity of the lower side of the outer peripheral surface of the plate cylinder 1 facing the ink roller 2, it is freely movable toward and away from the outer peripheral surface of the plate cylinder 1 by a cam or the like (not shown) in synchronization with the feeding of printing paper (not shown). A press roller 21 is provided as a pressing unit which is urged by a spring member (not shown) in a direction of pressing against the outer peripheral surface of the plate cylinder 1. The press roller 21 includes a pair of press roller arms 22, 22 fixed to both ends of an arm shaft 22 a rotatably supported by a housing side plate (not shown).
A well-known configuration in which the shaft portion is rotatably supported and held at a position separated from the outer peripheral surface of the plate cylinder 1 by a locking means (not shown) except when paper is passed.

At the lower right side of the plate cylinder 1 in FIG. 1, a paper feed tray (not shown) on which print paper (not shown) is loaded and lifted up and down, and a separate paper feed for separating and feeding the print paper one by one A paper feeder is provided which includes a member and a pair of registration rollers 20, 20 for conveying the separated and fed printing paper between the outer peripheral surface of the plate cylinder 1 and the press roller 21 at a time. ing. On the left side of the plate cylinder 1 in FIG. 1, a plate discharging device (not shown) for separating the used master 8 from the plate cylinder 1 and discharging the same is arranged. Below the plate discharging device, a peeling claw 24 whose tip is freely supported on the outer circumferential surface of the plate cylinder 1 for peeling the printing paper from the outer circumferential surface of the plate cylinder 1, and the peeling claw 24 peels and discharges the paper. A paper discharge device is provided which includes a paper discharge tray (not shown) for loading printed paper. Further, above the plate cylinder 1 and the plate making device 39, a document reading device (not shown) including a scanner 47 shown in FIG.

The detailed configuration of the operation panel 40 will be described with reference to FIG. The operation panel 40 is provided above the document reading device. The operation panel 40 includes a start key 41 as an operation start unit for starting a series of processes (operations) from reading of an image of a document to plate discharging, plate making, plate feeding, plate printing, and sheet discharging. , A numeric keypad 43 for setting and inputting the number of prints, a print key 42 for starting the printing operation for the number of prints set (input / input) by the numeric keypad 43, and displaying the operation status and messages. (LCD (Liquid Crystal Display)) display section 45 and the like. The LCD display unit 45 is driven via a liquid crystal drive circuit or the like.

Next, a control configuration of the plate-making printing apparatus 60 will be described with reference to FIG. In FIG. 2, reference numeral 50 denotes a control device for mainly controlling the plate making device 39 of the plate making printing device 60. The control device 50 has a C
PU (central processing unit), I / O (input / output) port,
A microcomputer having a ROM (read only storage device), a RAM (read / write storage device), a timer, and the like, and having them connected by a signal bus is provided.

The CPU of the control device 50 (hereinafter, may be simply referred to as “control device 50” for simplicity of description) constitutes the characteristic value detecting means group through the input port. , The image amount detecting means 48, the temperature sensor 30, and the humidity sensor 31, respectively, and receive data signals from these means and each sensor. The control device 50 is electrically connected to the master detection sensor 19 and the various keys (the start key 41, the print key 42, and the numeric key 43) of the operation panel 40 via the input port. An on / off signal and a data signal are received from the sensor 19 and the various keys.

The control device 50 electrically connects the LCD display unit 45 of the operation panel 40, the electromagnetic brake 37, the stepping motor 35, the first electromagnetic clutch 33, and the second electromagnetic clutch 34 via the output port. And various command signals are transmitted to the LCD display unit 45, the electromagnetic brake 37, the stepping motor 35, the first electromagnetic clutch 33 and the second electromagnetic clutch 34 via various drive circuits (not shown). I do. The control device 50 is electrically connected to the opening / closing plate driving means of the master stock means and the suction fan driving motor via the output port, and controls various driving circuits (not shown). Various command signals are transmitted to the opening / closing plate driving means and the suction fan driving motor via the control unit.

In this embodiment, the control device 50 has the following various control functions. First, the control device 50 includes an image amount detecting unit 48, a temperature sensor 30, and a humidity sensor 31.
The front tension applying means 38 changes the magnitude of the front tension F2 and the peripheral speed of the platen roller 10 based on each signal from the (characteristic value detecting means group).
First electromagnetic clutch 33 and stepping motor 35
Has a function as control means for controlling the

Second, the control device 50 serves as a stencil making operation control means for inhibiting a stencil making operation when the master 50 is different from a master set to be used in advance, based on a signal from a master type detecting means to be described later. It has the function of At this time, the control device 50 has a function of controlling the LCD display unit 45 to display, for example, "The master is different from the set master, replace the master with a proper one." .

The ROM in the control device 50 stores a data table obtained by an experiment or the like in advance for performing control by the control device 50 having the first and second functions, a program shown in FIG. A program for performing the operation of performing the operation is stored in advance. The RAM in the control device 50 performs input / output of these signals by temporarily storing the determination results and the calculation results of the CPU and storing output signals from the sensors and the like as needed. The master type detecting means detects the master 8 by the master stocking means based on the master detecting sensor 19, the master stocking means provided with the suction box 17, and the on / off signal from the master detecting sensor 19. The timer includes a timer of the control device 50 as a torsion suction timer for measuring the time when the torsion 8A is sucked.

Here, the image amount detecting means 48 not described above as the characteristic value detecting means will be described. The image amount detecting means 48 for detecting the amount of plate making image formed on the master 8 is described in paragraph (003) of JP-A-9-193526.
Means similar to those described in 3) and the like are used. That is, for the number of heating elements required to heat and pierce and make the entire master 8 for one plate, the master 8 is heated and pierced and made from the image information actually read by the scanner 47 of the original reading device. Ratio of the number of heating elements used to perform the operation, that is, the piercing rate (opening ratio) of the master 8
Is obtained, the amount of the plate-making image formed on the master 8 (in other words, substantially the same as the amount of the print image printed on the printing paper) is detected. The image amount detecting means 48 receives an analog image electric signal read and converted by an image sensor such as a CCD (Charge Coupled Device) provided in the scanner 47, and converts the digital image signal converted by the A / D conversion section. An image memory which receives the image electric signal of the image forming apparatus through the image signal processing device and temporarily stores the image electric signal as the image data, and sequentially accesses the image data once stored in the image memory to form the first plate formed on the master 8. The image signal processing device has a function of activating a plate making control device for controlling the drive of the thermal head 11 by detecting and recognizing the image amount of the plate making image.

Next, the operation will be described with reference to FIGS. First, a document (not shown) is set on a document table provided in a document reading device (not shown). In step S1, when a start key 41 of the operation panel 40 is pressed, a plate making start signal is generated. The plate making is started by inputting the data into 50. First, the scanner 47 is pre-scanned on the front side of the original to read the original image, and the image amount detecting means 48 detects the plate making image amount corresponding to the original, and the signal is transmitted to the control device 50. You. Then, based on the data signal from the image amount detecting means 48, the control device 50 checks the perforation ratio of the master 8 for one plate, and the temperature and humidity data from the temperature sensor 30 and the humidity sensor 31. Based on the signal, the peripheral speed of the platen roller 10 and the size of the front tension F2 are set as described later.

When the drive motor is driven, the plate cylinder 1 is rotated, and a used master (not shown) wound around the plate cylinder 1 is peeled and discarded by a plate discharging device (not shown). Next, the plate cylinder 1 is stopped at the plate feeding position, and the clamper 7 is opened by an opening / closing device (not shown) to enter a plate feeding standby state. The plate making process is started in parallel with the rotation of the plate cylinder 1 in the plate discharging process.

That is, when the stepping motor 35 is driven, the platen roller 10 and the pair of conveying rollers 12a and 12b start rotating, and the master 8 is conveyed while being pulled out from the master roll 8a.
A force is applied to the leading end portion of the master 8 in the direction in which it is lifted upward by the pair of reversing rollers 14a and 14b inclined as described above, and the opening / closing plate 16 occupies the guide transport position. Due to the existence and the stopped state where the leading end of the master 8 is sandwiched by the pair of reversing rollers 14a and 14b, the leading end of the master 8 is raised upward in a convex shape as shown in FIG.
Is formed. When the deflection 8A reaches a predetermined size, it is turned on and detected by the master detection sensor 19 (see step S2).

After a lapse of a set delay time from the ON / detection of the master detection sensor 19, the opening / closing plate driving means is driven to rotate the opening / closing plate 16 from the state where it occupies the guide conveyance position to the deflection suction position. The suction port is displaced to form a suction port above the suction box 17, and the suction fan drive motor drives the suction fan 18 to rotate, whereby the left side of the suction box 17 in FIGS. Then, the air flow from the right side to the right side is generated, so that the deflection 8A formed at the leading end of the master 8 is stored while being drawn in (step S3).
reference). When the deflection 8A at the tip of the master 8 is sucked and the deflection 8A becomes small and is not detected by the master detection sensor 19, the master detection sensor 19
Is turned off, and the control device 50 determines whether the detection is turned off within a predetermined set time (Step S).
4, see step S5).

In the case of the stiff master 8 as the type of the master, the deflecting suction time until the deflecting 8A of a predetermined size is sucked and drawn in by the suction box 17 is prolonged, whereby the master detecting sensor 19 is turned off. The time to do it becomes longer. On the other hand, in the case of the master 8 having a weak waist, the suction box 17
Since A is immediately sucked and drawn, the time until the master detection sensor 19 is turned off is shortened. As described above, the timer of the control device 50 measures the deflection suction time when the deflection box 8A of a predetermined size is sucked by the suction box 17 based on the on / off signal from the master detection sensor 19. Thus, the type of master corresponding to the strength of the waist of the master 8 can be detected as a substitute for the strength of the waist of the master 8.

At this time, based on the signal from the timer, the controller 50 determines that the master is different from the master set to be used in advance, that is, the deflection suction time from the timer is not within the predetermined set time. In such a case, the plate making operation is prohibited and stopped, and the LCD display unit 45 is controlled to display, for example, a message saying "The master is different from the set master, so replace the master with a regular one." Let In this case, the operator operates the LCD display 45
The operation for replacing the master roll 8a with the regular master roll 8a is performed according to the message displayed in Step S7 and Step S8. Conversely, step S
5, when the control device 50 determines that the master is set to be used in advance, that is, when it is determined that the master is within a predetermined set time from a data signal relating to the deflection suction time measured by the timer. Then, the prepress operation is continued. (See step S6).

In step S1 of FIG. 5, the back tension F1 after the start of the plate making operation is set in advance to be larger than the front tension F2 as described above. This is a problem as described in the related art, that is, when the plate-making master 8 is conveyed by the platen roller 10, the non-perforated portion where the frictional force (conveyance resistance) does not increase and the conveyance delay does not easily occur. This is to prevent the slack due to the uneven feeding of the master 8 from occurring in the perforated portion where the conveyance delay occurs due to the increase in the frictional force (conveyance resistance). In addition to this, the control device 50 transmits a data signal relating to temperature detection of the main body of the plate making device 39 from the temperature sensor 30, a data signal relating to the plate making image amount formed on the master 8 from the image amount detecting means 48, and a humidity signal. Sensor 31
The following control is performed on the basis of the data signal relating to the humidity detection of the main body of the plate making apparatus 39 from. That is, the control device 50
In a high-temperature environment where the temperature is high and the strength of the master 8 is liable to decrease due to softening, the first electromagnetic clutch 33 reduces the front tension F2 so as not to stretch the perforated and prepressed master 8. Control. In addition, when the transport resistance of the master 8 is large due to the large number of perforated image portions, or when the humidity is so high that moisture or the like adheres to the surface of the master 8, the master 8 easily sticks to the contact surface with the thermal head 11. In a high-humidity environment where the frictional force with the plate 11 increases, the stepping motor 35 is controlled to increase the peripheral speed (conveyance speed) of the platen roller 10 so that a conveyance delay does not occur. Further, when the number of perforated image portions is large and the master 8 is easily contracted, the first electromagnetic clutch 33 is controlled so that the front tension F2 is also increased, thereby preventing the master 8 from contracting in plate making and preventing the master 8 from being wrinkled. To do. In this case, since the conveyance resistance of the master 8 also increases, the reproducibility of the image of the plate-making image may be deteriorated due to slippage with the platen roller 10, so that the rotation speed of the platen roller 10 is slightly increased. The stepping motor 35 is controlled as described above. With the continuous rotation of the suction fan 18, the master 8 is made into a plate while being successively drawn into the suction box 17 while being stored in the suction box 17.

On the other hand, at about the same time as the rotation of the platen roller 10 starts, the original is conveyed to the original reading section. The optical information of the document read by the scanner 47 of the document reading unit is photoelectrically converted into an analog image signal by an image sensor,
Further, based on a digital image signal processed and transmitted via the A / D converter and the plate making control device,
The heat generating element of the thermal head 11 is energized by pulse-selection to generate heat, and the master 8 is selectively heated and melted according to image information to perform perforation and plate making.

On the other hand, the plate cylinder 1 is rotated and stopped until the clamper 7 reaches the plate feeding position which is substantially on the right side in FIG. When the plate cylinder 1 stops at the plate feeding position, the clamper 7 is opened by the opening / closing device, and the plate feeding is in a standby state. At the same time as the release of the clamper 7, the second electromagnetic clutch 34 is energized under a command from the control device 50, whereby the rotational driving force of the stepping motor 35 is transmitted to the reversing roller 14a via the rotation transmitting member. , So that the reversing roller pair 1
4 a and 14 b rotate by a predetermined angle, and the leading end of the master 8 is guided by the guide plate 15 and inserted between the stage 6 and the clamper 7. The pair of reversing rollers 14a and 14b rotate by a predetermined angle, and the stepping motor 35
Has reached a certain set value and the master 8
Is determined to have reached between the stage 6 and the clamper 7, the clamper 7 is closed by the opening / closing device, and the leading end of the master 8 that has been made is adsorbed between the stage 6 and the clamper 7. It is pinched.

After clamping the leading end of the master 8 after the plate making, the plate cylinder 1 resumes rotation by the driving of the electric motor, and the master 8 after the plate making is pulled out from the suction box 17 while the reversing roller pair 14a, 14b The plate is fed onto the outer peripheral surface of the plate cylinder 1 and is wound on the outer peripheral surface of the plate cylinder 1 without generating winding wrinkles. When it is determined that the master drive to the master 8 and the conveyance of the master 8 having the set amount of the master made by the rotation of the stepping motor 35 by the predetermined number of steps have been completed, the rotation of the stepping motor 35 is stopped and the platen is stopped. The rotation of the roller 10, the pair of conveying rollers 12a and 12b, and the pair of reversing rollers 14a and 14b is stopped, and the cutter 13 is operated to cut the master 8 having been made.
At this time, the cutting of the master by the cutter 13 is completed before the master 8 is completely pulled out from the suction box 17 due to the rotation of the plate cylinder 1, so that the rear end of the master 8 is not torn off. It has become.
At this time, when the second electromagnetic clutch 34 is turned off, the pair of reversing rollers 14a and 14b is rotated and driven by the rotation of the plate cylinder 1 via the master 8, so that the master 8 The generation of wrinkles can be more reliably prevented by the application of a large tension. Then, the rear end of the cut master 8 that has been cut is pulled out of the plate making device 39 by the rotation of the plate cylinder 1, and is completely wound on the outer peripheral surface of the plate cylinder 1 at the stage of plate making on the plate cylinder 1. At the same time as the winding of the completed master 8 is completed, the remaining of the master 8 and the like are determined by a sensor or the like provided near the suction port of the suction box 17.

When winding of the master 8 having been made on the plate cylinder 1 is completed, a printing process is started. That is, one sheet of printing paper stacked on the sheet feeding tray is separated and fed by the separation sheet feeding member of the sheet feeding device, and the timing is adjusted by the registration roller pairs 20 and 20 so that the printing drum 1 It is transported between the outer peripheral surface and the press roller 21. When the passage of the printing paper is detected by a paper detection sensor (not shown) disposed near the downstream of the registration roller pair 20, 20 in the master transport direction X, the locking means is released, and the press roller 21 is released. Is continuously pressed by the prepressed master 8 (not shown in FIG. 1), which is wound around the outer peripheral surface of the plate cylinder 1, by the urging force of the spring member. What is called plate printing is performed for bringing the master 8 into close contact with the outer peripheral surface of the plate cylinder 1. In this printing, the ink oozes from the perforated portion of the plate cylinder 1 to the perforated portion of the stencil master 8 and is transferred to the surface of the printing paper, thereby performing stencil printing.
At this time, the ink roller 2 also rotates in the same direction as the rotation direction of the plate cylinder 1. The ink in the ink reservoir 4 is attached to the surface of the ink roller 2 by the rotation of the ink roller 2, and the amount thereof is regulated when passing through the gap between the ink roller 2 and the doctor roller 3. Supplied to

The leading end of the stencil-printed printing paper is separated from the printing drum 1 by a peeling claw 24 approaching the outer peripheral surface of the printing drum 1.
The printing paper that has been peeled off from the master 8 that has already undergone plate making and that has been peeled off is discharged and stacked on the discharge tray. After the printing, the press roller 21 separates from the plate cylinder 1 and returns to the initial position shown in FIG. In parallel with the printing and printing process, the opening / closing plate 16 is rotated and displaced 90 degrees clockwise to occupy the guide conveyance position.
The rotation of the suction fan 18 stops.

Thereafter, the platen roller 10, the tension roller upper / lower pair 9b, 9a and the reversing roller pair 14a, 1
4b resumes rotation, and the cut end of the master 8 is fed toward the nip portion of the pair of reversing rollers 14a, 14b. When it is determined from the pulse number of the stepping motor 35 that the cut end of the master 8 has reached the nip portion of the pair of reversing rollers 14a and 14b and has been nipped, the platen roller 10, the tension roller upper and lower pairs 9b and 9a, and the reversing roller pair The rotation of 14a, 14b stops, and at the same time, the opening / closing plate 16 also rotates counterclockwise to return to the initial position of the deflection suction position, and enters a plate-making standby state for the next plate-making.

After completion of the printing, the operator visually checks the printed matter discharged to the paper discharge tray and appropriately determines whether or not to perform a normal printing operation. When the number of sheets is set and the print key 42 is pressed, the same operations of feeding, normal printing, and discharging as described above are sequentially performed.

FIG. 6 shows a modification of the above embodiment. This modification is different from the above embodiment only in that a plate making device 39A is provided instead of the plate making device 39 of the above embodiment. The plate making device 39A has a configuration in which, compared to the plate making device 39, the master 8 on the downstream side of the platen roller 10 in the master conveying direction X or the master 8 after plate making is conveyed away from the thermal head 11. The only difference is that. Specifically, the nip portion of the transport roller middle pair 12a, 12b is
6 so as to be located above the nip formed by the thermal head 11 and the pair of transport rollers 1 in FIG.
2a, 12b, the master 8 between the platen roller 10 and the thermal head 11, and the middle of the conveying rollers so that the angle A formed between the master 8 and the extension of the horizontal plane of the thermal head 11 where the heating elements are arranged is an acute angle. 12a and 12b, a platen roller 10 and a thermal head 11 are arranged.

According to this modification, the platen roller 10
The master 8 or the pre-made master 8 is configured to be conveyed in a direction away from the thermal head 11 so that the master 8 or the pre-made master 8 on the downstream side in the master conveyance direction X is moved away from the thermal head 11. Can be prevented from being deformed by receiving
Wrinkles can be prevented.

The embodiment of the present invention is not limited to the above-described embodiment and modified example, but controls the size of the fine front tension F2 and controls the platen roller 10 by the control device 50 as in the above-described embodiment and modified example. If it is not necessary to control the peripheral speed so much, the image amount detecting means 48 as the characteristic value detecting means, the temperature sensor 3
0, a humidity sensor 31 is provided, and the control means controls the magnitude of the front tension F2 or the platen roller 10 based on a signal from any one of the characteristic value detecting means. (Refer to claims 5, 6, and 7). Further, the image amount detecting means 48 as the characteristic value detecting means, the temperature sensor 30,
If it is desired to control the size of the front tension F2 and control the peripheral speed of the platen roller 10 with a finer grain than that provided by arranging any one of the humidity sensors 31, the control means may include: The control of the magnitude of the front tension F2 and the control of the peripheral speed of the platen roller 10 may be performed based on each signal from at least two or more of the characteristic value detecting means (see claim 8). .

The embodiment of the present invention is not limited to the above-described embodiment, the modified example, the above-described control configuration, and the like. The control of the size of the front tension F2 and the control of the peripheral speed of the platen roller 10 are finer. If it is desired, the type of the master may be applied as the characteristic of the master expansion / contraction-related factors, and the master type detecting means for detecting the type of the master may be configured as the characteristic value detecting means. That is, in addition to the signals from the image amount detecting means 48 as the characteristic value detecting means, the temperature sensor 30 and the humidity sensor 31, the control device 50 outputs a signal relating to the master type from the timer as the master type detecting means. , The function of controlling the first electromagnetic clutch 33 and the stepping motor 35 of the front tension applying means 38 so as to change the size of the front tension F2 and the peripheral speed of the platen roller 10 is added. In this case as well, only one of the timers is individually provided, or the magnitude of the front tension F2 is determined based on signals from at least two or more of the characteristic value detecting means including the timer. The control and the control of the peripheral speed of the platen roller 10 may be performed.

The embodiment of the present invention is not limited to the above-described embodiment, the above-described modified example, the above-described control configuration, and the like, and may be as follows. In other words, the control structure may be such that there is a control means for controlling the electromagnetic brake 37 as the braking means so as to change the braking force based on the signal of the master type from the timer of the master type detecting means. See section 9). In this case, for example, the tension roller upper and lower pairs 9b and 9a are configured to be detachable from the plate making side plate pair, and the braking roller according to the type of the master is mechanically applied in advance. Top and bottom 9
A configuration example in which a plurality of b and 9a are prepared and made detachable is also included.

The master 8 is not limited to the one described above, and may be a master in which the thickness of the porous support of the master 8 is reduced. For example, Japanese Patent Application Laid-Open No. 11-7794 proposed by the present applicant.
The synthetic fiber base master 2 described in Japanese Patent Publication No. 9 may be used, or a master in which a molten resin is applied to a synthetic resin film to form a resin film integrally with the synthetic resin film may be used. Can be. As described above, if it is possible to control the peripheral speed of the back tension F1, the front tension F2, or the platen roller 10 according to the type of the master, the conventional problems can be solved and the effects described later can be achieved. In addition, it goes without saying that it is possible to improve the print quality, reduce the cost of the master (plate) itself, and reduce the printing cost according to the type of master used.

The embodiments of the present invention are not limited to the above-described embodiments, the above-described modified examples, the above-described control configurations, and the like, and the effects of the inventions described in claims 3 to 8 described below may not be so desired. If so, the first electromagnetic clutch 33 as a torque limiter is removed from the configuration of the above-described embodiment, and the gear ratio of the rotation transmitting means is appropriately changed to change the peripheral speed of the pair of transport rollers 12a and 12b to the platen roller. Set it slightly larger than that of 10,
A substantially constant front tension may be applied to the master 8 between the transport roller middle pair 12a, 12b and the platen roller 10 (see claim 1).

As described above, the present invention has been described with respect to the specific embodiments and modifications or the examples included therein, but the configuration of the present invention is not limited to the above. Those skilled in the art will appreciate that various embodiments and examples can be configured in accordance with the necessity, purpose, application, and the like, within the scope of the present invention, by appropriately combining these or singly. it is obvious.

[0079]

As described above, according to the present invention,
A new plate-making apparatus and plate-making printing apparatus can be provided by solving the problems of the conventional apparatus as described above. The effects of each claim are as follows. According to the first aspect of the present invention, the back tension is made larger than the front tension, so that a higher back tension is given to the master on the rotation entrance side of the platen roller, and the master and the platen roller on the rotation entrance side of the platen roller. By causing a slight slip between them and moving the master uniformly downstream in the master transport direction,
The master on the upstream side in the master transport direction may be slackened due to a local transport delay due to an increase in the transport resistance of the master perforated portion, or the transport resistance may be reduced, for example, by the master transport unit disposed on the downstream side in the master transport direction. The unsewn plate making part with a small amount is pulled out and the slack generated on the master on the upstream side in the master conveyance direction is promoted, and the slack that is crushed by the platen roller and wrinkles can be prevented. It is possible to prevent wrinkles even when using a master with a thin porous support or a master without a porous support, as well as a master with no porous support, and thus improve the image dimensional reproducibility during plate making. Becomes possible.

According to the second aspect of the present invention, the back tension applying means is provided between the master storage means and the platen roller, and is provided with a tension roller which is rotatable in contact with the master on the upstream side in the master transport direction. And braking means for braking the rotation of the tension roller,
In addition to the effects of the first aspect of the present invention, the back tension can be reliably applied to the master upstream of the platen roller in the master transport direction with a simple configuration.

According to the third aspect of the present invention, the front tension applying means is provided on the downstream side in the master transport direction, contacts the master on the downstream side in the master transport direction, and moves the master to the downstream side in the master transport direction. A transport roller that rotates, a transport roller driving unit that rotates the transport roller at a peripheral speed higher than a peripheral speed of the platen roller, and a torque limiter provided between the transport roller and the transport roller drive unit. Thus, in addition to the effect of the first aspect, it is possible to reliably apply a fixed front tension to the master downstream of the platen roller in the master transport direction with a simple configuration.

According to the fourth aspect of the present invention, the control means is based on a signal from the characteristic value detecting means for detecting a characteristic value of a master expansion / contraction-related factor which affects expansion / contraction of the master plate making dimension during plate making. By controlling the front tension applying means so as to change the magnitude of the front tension, the characteristic value of the master expansion / contraction-related factor detected by the characteristic value detecting means can be obtained in addition to the effect of the invention according to claim 1 or 3. The size of the front tension can be automatically changed according to the size, height, etc. of the
It is possible to reliably prevent the master plate making dimension from changing due to the expansion or contraction of the master, and to further improve the image dimension reproducibility. According to the fifth aspect of the present invention, the characteristic value detecting means includes the image amount detecting means for detecting the amount of the plate making image, so that the effect of the invention according to the fourth aspect is exerted according to the amount of the plate making image. .
According to the sixth aspect of the present invention, the characteristic value detecting means includes a temperature detecting means for detecting at least one of the internal and external temperatures of the plate making device main body,
The effect of the invention described in claim 4 is exerted according to the level of the temperature. According to the seventh aspect of the present invention, the characteristic value detecting means includes humidity detecting means for detecting at least one of humidity inside and outside of the plate making apparatus main body, so that the characteristic value detecting means can be operated in accordance with the level of the humidity. Thus, the effects of the invention described in claim 4 are exhibited.

According to the present invention, the control means controls the front tension applying means so as to change the magnitude of the front tension based on each signal from at least two or more characteristic value detecting means. By doing
According to the magnitude of the characteristic value of the master expansion / contraction related factors, etc.,
Claims 4 and 5 can be handled more finely.
The effects of the invention described in 5, 6, or 7 are exhibited.

According to the ninth aspect of the present invention, the braking means can change the magnitude of the back tension by changing the braking force according to the type of the master. Regardless of the type, the effect of the invention described in claim 2 is achieved.

According to the tenth aspect of the present invention, there is provided a stencil making operation control means for inhibiting the stencil making operation based on a signal from the master type detecting means when the stencil is different from a master set to be used in advance. Thus, in addition to the effects of the above inventions, it is possible to prevent problems such as wrinkles of the master which may be caused by performing a plate making operation using a master different from a master set to be used in advance. be able to.

According to the eleventh aspect of the present invention, the master type detecting means includes a deflection detecting means for detecting the deflection of the master formed in a predetermined size, and a means for sucking and temporarily storing the deflection of the master. Based on the suction and storage means and the deflecting suction time measuring means for measuring the time when the deflecting of the master is sucked by the suction and storing means based on the signal from the deflecting detecting means, for example, the strength of the waist of the master ( Since it is possible to use the fact that the strength of the master varies depending on the type of master, the type of master can be detected with a simple configuration in the configuration of a normal plate making apparatus having suction and storage means.

According to the twelfth aspect of the present invention, a master located downstream of the platen roller in the master transport direction or a stencil master is transported in a direction away from the thermal head. In addition to this, it is possible to prevent the master or the master made by plate making from being deformed due to the heat storage of the thermal head and the like, and furthermore to prevent the master from being wrinkled more reliably.

According to the thirteenth aspect of the present invention, the first aspect
Or a plate making and printing apparatus for winding a master made by the plate making apparatus on a plate cylinder, whereby a master winding on a plate cylinder is achieved. It is possible to prevent the occurrence of wrinkles and the like at the time of mounting, and to improve image size reproducibility.

[Brief description of the drawings]

FIG. 1 is a partially sectional front view of a plate making printing apparatus and a plate making apparatus showing an embodiment of the present invention.

FIG. 2 is a partially sectional front view of the plate making apparatus including a simplified block diagram of the plate making apparatus.

FIG. 3 is a plan view of a main part of the operation panel.

FIG. 4 is a partial cross-sectional front view of a main part of the plate making device showing an operation of the plate making device.

FIG. 5 is a flowchart showing a plate making operation of a main part.

FIG. 6 is a partial cross-sectional front view of a plate making apparatus showing a modification of the embodiment.

[Explanation of symbols]

Reference Signs List 1 plate cylinder 2 ink roller constituting ink supply means 8 master 8c master supporting member 9a, 9b lower / upper tension roller 10 platen roller 11 thermal head 12a, 12b middle pair of transport rollers 6a, 6b cutter 17 suction Suction box constituting storage means 19 Master detection sensor as deflection detecting means 30 Temperature sensor as temperature detecting means 31 Humidity sensor as humidity detecting means 33 First electromagnetic clutch as torque limiter 35 Stepping motor as transport roller driving means 36 Back tension applying means 37 Electromagnetic brake as braking means 38 Front tension applying means 39, 39A Plate making device 40 Operation panel 48 Image amount detecting means 50 Control device as control means and plate making operation controlling means 60 Prepress printer F1 Back tension F2 Front tension X Master transport direction

Claims (13)

[Claims] 1. A master storage means for storing a master so as to be able to be fed out, a thermal head for heating and making a master according to image information, and moving the master to the downstream side in the master transport direction while pressing the master against the thermal head. A plate making device having a rotatable platen roller; a back tension applying means for applying a back tension to a master upstream of the platen roller in the master transport direction; and a downstream side of the platen roller in the master transport direction. And a front tension applying means for applying a front tension to the master, wherein the back tension is larger than the front tension. 2. The plate making apparatus according to claim 1, wherein the back tension applying means is disposed between the master storage means and the platen roller, and rotates in contact with the master on the upstream side in the master transport direction. A plate making apparatus comprising: a flexible tension roller; and braking means for braking the rotation of the tension roller. 3. The plate making apparatus according to claim 1, wherein the front tension applying means is disposed downstream of the master transport direction, and contacts the master downstream of the master transport direction. Rotatable transport roller for moving the master to the side, transport roller driving means for rotating the transport roller at a peripheral speed higher than the peripheral speed of the platen roller, and between the transport roller and the transport roller drive means. A plate making device comprising: a torque limiter provided. 4. A plate making apparatus according to claim 1, wherein said characteristic value detecting means detects a characteristic value of a master expansion / contraction-related factor which affects expansion / contraction of a master plate making dimension during plate making. Control means for controlling the front tension applying means so as to change the magnitude of the front tension based on a signal from the means. 5. The plate making apparatus according to claim 4, wherein the characteristic of the master expansion / contraction factor is a plate making image amount formed on a master, and wherein the characteristic value detecting means detects the plate making image amount. A plate making device comprising a detecting means. 6. The plate making apparatus according to claim 4, wherein the characteristic of the master expansion / contraction factor is at least one of an internal temperature and an external temperature of the plate making apparatus main body. A plate making apparatus comprising a temperature detecting means for detecting at least one of the temperatures. 7. The plate-making apparatus according to claim 4, wherein the characteristic of the master expansion / contraction-related factor is at least one of humidity inside and outside of the plate-making apparatus main body, and the characteristic value detecting means includes: A printing apparatus comprising a humidity detecting means for detecting at least one of the humidity. 8. The plate making apparatus according to claim 4, wherein said control means determines the magnitude of said front tension based on each signal from at least two or more characteristic value detecting means. A plate making apparatus characterized in that the front tension applying means is controlled so as to be changed. 9. A plate making apparatus according to claim 2, wherein said braking means can change the braking force according to the type of master. 10. A plate making apparatus according to claim 1, wherein said master type detecting means detects a type of said master, and is used in advance based on a signal from said master type detecting means. A plate making operation control means for prohibiting a plate making operation when the master is different from the master set as described above. 11. A plate making apparatus according to claim 10, wherein said master type detecting means detects deflection of a master formed in a predetermined size, and temporarily stores the suction of said master by sucking it. Suction and storage means for performing the measurement, and based on a signal from the deflection detection means, a deflection time measurement means for measuring a time when the master deflection is sucked by the suction storage means. Plate making equipment. 12. A plate making apparatus according to claim 1, wherein a master or a master made downstream of said platen roller in said master conveying direction is transported away from said thermal head. A plate making apparatus characterized in that the plate making is performed. 13. A plate cylinder having the above-described plate-making apparatus according to any one of claims 1 to 12, wherein a master made by the plate-making apparatus is wound, and ink is applied to the master on the plate cylinder. A plate-making printing apparatus comprising: an ink supply unit that supplies printing ink to a master on the plate cylinder to perform printing on the printing paper.