JPH071699A - Plate making device in stencil printing press - Google Patents

Abstract

PURPOSE:To obtain a plate making device capable of setting a master without generating wrinkles in a stencil printing press by a method wherein a master is set by being inserted straight into between a thermal head and a platen roller. CONSTITUTION:By depressing a setting key, a cam 47 is rotated by the rotation of a lifting motor, and a master roll 1R and a roll holder 2 are displaced to an initial setting position. After the both come to a stop at the initial setting position, the leading end of a master 1 is manually payed out of the master roll 1R and hangingly inserted to a space between a thermal head 4 and a platen roller 3 disposed at a second position. In this manner, the leading end of the master 1 is inserted straight into the space between the thermal head 4 and the platen roller 3 while abutting on the peripheral surface of the platen roller 3, thereby being hung down straight under its own weight.

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 for punching a heat-sensitive stencil printing master with a thermal head or the like.

[0002]

2. Description of the Related Art Digital thermal stencil printing has been known as a simpler printing method, and a thermal head in which fine heating elements are arranged in a line is pressed against a thermal stencil master by using a platen roller, and pulse printing is performed. The heat-sensitive stencil master is conveyed while electrically energizing the heating element of the thermal head to generate heat, so that the heat-melt stencil master is perforated based on the image information, and then the heat-sensitive stencil master is automatically conveyed to the porous cylindrical plate cylinder. A print image is formed by automatically wrapping around the outer peripheral surface and continuously pressing the printing paper against the heat-sensitive stencil master by pressing means such as a press roller to pass ink from the perforated portion and transfer it to the printing paper. It is like this. The heat-sensitive stencil master used for such stencil printing is composed of a thermoplastic synthetic resin film such as a very thin polyester (hereinafter simply referred to as "film") and an ink-permeable porous flexible support. It has a laminated structure in which fibers, Japanese paper, or a mixture of Japanese paper and synthetic fibers are stuck together, and usually the surface of the film is used to prevent fusion with the thermal head surface and to prevent charging. An overcoat layer is formed.

Since fibers such as Japanese paper used for the support of the heat-sensitive stencil master are thick and have uneven density,
In the area where fibers such as Japanese paper are entangled or lumps, the passage of ink is obstructed, the ink does not transfer to the printing paper, the solid part comes off, or the image part such as letters and fine lines is faint. There is a problem that a so-called defective fiber grain phenomenon such as breakage or appearance of a fiber pattern is generated and the image quality is deteriorated. Therefore, printing is performed using a master for heat-sensitive stencil printing (hereinafter simply referred to as “master”) that is substantially composed of a film in which washi or the like serving as a support is deleted, and Attempts have been made to reduce the printing cost and the cost of masters.

[0004]

However, while the thickness of the conventional heat-sensitive stencil master having a laminated structure is about 50 μm, the thickness of the master is about 2 to 8 μm.
Since the thickness becomes very thin, the strength (strength of the waist) is remarkably reduced, which makes it very difficult to set the platen roller and the thermal head.

As described above, the master roll formed by winding the master in a roll shape is used for the plate making apparatus in the conventional stencil printing machine, and the thermal head and the platen are set when the master roll is set (including replacement). Although the method of releasing the pressed state with the roller and inserting the tip of the master is set, it is extremely difficult to insert it straight in the axial direction of the platen roller which is also the master transport member. It is difficult to insert, and it is unavoidable to insert it at a slight angle. Since the master is inserted and set in this manner, wrinkles occur when the leading end of the master is pressed against the platen roller by the thermal head and conveyed by the rotation of the platen roller. A conventional heat sensitive stencil master has thickness and stiffness, so it is possible to remove wrinkles by performing waste feeding (however, a lot of waste masters are generated), but practically only film With a very thin master consisting of, since there is almost no stiffness in the waist, it can not be expected that wrinkles will disappear naturally if they occur, so a plate making device that can set without wrinkles is desired. Was there. Also, it is necessary to insert the master between the thermal head and the platen roller,
It was extremely difficult to insert and had poor workability.

Therefore, as disclosed in, for example, Japanese Unexamined Patent Publication No. 59-16789, there is proposed a technique in which a thick reinforcing portion or ear paper is provided at the leading end (heading portion) of a master (roll type base paper). Has been done.

However, in the above technique, although it is effective when it is inserted between the thermal head and the platen roller, it is very difficult to insert it straight and set it, and it is difficult to set it without causing wrinkles. Very difficult. Even if you set it properly, the tip of the master will be cut and removed, so if you accidentally release the pressed state of the thermal head against the platen roller, wrinkles can be avoided during resetting. There is no problem.

Therefore, in order to solve the above problem, the present invention aims to insert the master straight between the thermal head and the platen roller and set it, and to set it without wrinkling. An object of the present invention is to provide a plate making device in a stencil printing device.

[0009]

The invention according to claim 1 is
Master storage means for storing a roll-shaped master for heat-sensitive stencil printing, a thermal head for perforating and making the master based on image information, and a platen for transporting the master to the downstream side of the master transport path while pressing the master against the thermal head. In a plate making apparatus in a stencil printing apparatus having a plate making means comprising a roller and a cutting means for cutting the master, which is provided on the downstream side of the master conveying path, the thermal head is provided via the master. A thermal head contact / separation mechanism for contactably and separably displacing the first position pressed against the platen roller and a second position separated from the platen roller, and a position above the platen roller for the master storage means. Then, a holding means for holding the platen roller in parallel with the axial direction thereof is provided.

According to a second aspect of the present invention, there is provided a master storing means for storing a roll-shaped master for heat-sensitive stencil printing, a thermal head for perforating the master based on image information, and pressing the master against the thermal head. A plate making apparatus in a stencil printing apparatus having a platen roller configured to convey to the downstream side of the master conveying path, and a cutting section provided to the downstream side of the master conveying path to cut the master. A thermal head contact / separation mechanism for displaceably contacting and separating the thermal head between a first position for pressing the thermal head against the platen roller via the master and a second position separated from the platen roller; When the head occupies the first position, the platen roller conveying force generated by pressing the master is transferred from the master roll to the master roller. The thermal head pressing force can be switched between a third position for holding the thermal head within a range smaller than the platen roller pulling output for pulling out the star and a fourth position where the platen roller conveying force is larger than the platen roller pulling output. And a mechanism.

[0011]

According to the invention described in claim 1, when the thermal head occupies the second position by the thermal head contact / separation mechanism, the holding means is provided between the platen roller and the thermal head at a position above the platen roller. The master is set straight while the tip of the master is hung from the master storage means held by and is inserted by its own weight. When the thermal head occupies the first position, the master is set straight.

According to the second aspect of the present invention, when the thermal head occupies the second position by the thermal head contacting / separating mechanism, the tip of the master is inserted between the platen roller and the thermal head, and the thermal head contacting / separating mechanism is inserted. When the thermal head occupies the first position by the separating mechanism, the master is pressed in the range where the platen roller conveying force is smaller than the platen roller pulling output at the third position where the thermal head pressing force switching mechanism holds the thermal head. By doing so, tension is evenly applied over the entire surface of the master, and the master is stretched evenly without slack, and then the master moves to the fourth position where the platen roller transport force is larger than the platen roller pulling output, and the master does not slacken. It is set in a state where it does not occur.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) In FIG. 1, reference numeral 50 indicates a plate making apparatus in a stencil printing apparatus. The plate making device 50 is
A master storage means 100 for storing a roll-shaped master 1 for heat-sensitive stencil printing which is substantially composed of a thermoplastic synthetic resin film, a thermal head 4 for perforating the master 1 based on image information, and a master 1 for this. The platen roller 3 that conveys to the downstream side of the master conveyance path P while pressing
And a heater wire 7 as a cutting means for cutting the master 1, which is provided on the downstream side of the master conveyance path P, and a thermal head 4 on the platen roller 3 via the master 1. A thermal head contact / separation mechanism 1 for displacing the thermal head 4 so that the thermal head 4 can be freely contacted / separated between a first position for pressing and a second position separated from the platen roller 3.
30 and the master storage means 100 as a holding means for holding the master storage means 100 at a position above the platen roller 3 in parallel with the axis 3s of the platen roller 3 and rotatably with respect to the axis 3s of the platen roller 3. The roll holder 2 is mainly included.

A master for heat-sensitive stencil printing consisting essentially of a thermoplastic synthetic resin film (hereinafter simply referred to as "master") means that the master is made of only the thermoplastic synthetic resin film, A synthetic resin film containing a trace amount of components such as an antistatic agent, and one thin film layer such as an overcoat layer on both main surfaces of the thermoplastic synthetic resin film, that is, at least one of the front surface and the back surface. Alternatively, it includes one formed by forming a plurality of layers.

Hereinafter, the master storing means 100, the roll holder 2, the plate making means 110, and the thermal head contact / separation mechanism 130.
The cutting means will be sequentially described.

As shown in FIG. 1 or 5, the continuous sheet-shaped master 1 is wound around a synthetic resin core tube 1s to form a master roll 1R. The core tube 1s projects from both end surfaces of the master roll 1R and is formed longer than the width of the master 1. The master roll 1R has the roll holder 2 of the roll holder 2 in the vicinity of the protrusion from each end face.
b (shown in FIG. 5) is supported so as to be rotatable in the direction of arrow A (counterclockwise direction) and to be able to be extended. As described above, the master storage means 100 is composed of the core tube 1s and the roll holder 2b (shown in FIG. 5) that supports the core tube 1s.

In FIG. 1, the platen roller 3 has its shaft 3s rotatably supported by a side plate (not shown) of the stencil printing machine, and is indicated by an arrow A by a stepping motor 3M fixed to a machine frame (not shown) of the stencil printing machine. It is driven to rotate in the direction (counterclockwise). As shown in FIG. 1 or FIG. 5, the roll holder 2 is formed so as to sandwich both ends of the platen roller 3 and both ends of the master roll 1R, and has a substantially H shape, and has a base end portion. Is formed with a bearing portion 2a having an all-wheel shape, and a roll holding portion 2b having a substantially spanner shape is formed at a free end portion thereof. A shaft 3s at both ends of the platen roller is rotatably supported by a bearing portion 2a, and a core tube 1s at both ends of the master roll 1R is rotatably supported by a roll holding portion 2b. Stoppers 2c for preventing the respective end surfaces of the core tube 1s from coming off are formed on both roll holding portions 2b. The roll holder 2 is a shaft 3s of the platen roller 3.
On the other hand, the size and phase of each part are determined so that the core tube 1s of the master roll 1R is set in parallel. The roll holder 2 is made of, for example, an aluminum alloy,
The connecting portion 2j is integrally formed with the pair of left and right roll holder bodies.

As shown in FIG. 5, a cam 47 having a shaft 48 which is rotatably supported by a machine frame of a stencil printing machine (not shown) is provided on the lower surface of the substantially central portion of the roll holder 2 so as to be in constant contact therewith. ing. An elevating motor (not shown) that is rotationally driven via a gear (not shown) is connected to the shaft 48. A tension spring 4 whose one end is locked to a machine frame of a stencil printing machine (not shown) is provided at a substantially central portion of the roll holder 2.
The other end of 9 is locked, and the pulling spring 49 gives the habit of pressing the lower surface of the roll holder 2 against the short diameter peripheral surface of the cam 47.

With the above structure, the master roll 1R and the roll holder 2 can be selectively displaced from the plate making position shown by the phantom line in FIG. 1 to the initial setting position shown by the solid line. As shown in FIG. 1 or 2, the thermal head 4
Is provided so as to extend parallel to the shaft 3s of the platen roller 3, and the head holder 5 is attached to the back surface thereof. The head holder 5 is made of, for example, an aluminum alloy, and a head holder shaft 6 rotatably supported by a machine frame (not shown) of the stencil printing machine is attached to the base end portion thereof substantially integrally. The thermal head 4 is a well-known device that selectively melts and punches the master 1 based on a digital image signal that is processed and sent by an A / D conversion unit and a platemaking control unit (both not shown) of a document reading unit (not shown). Have a function. A pin 5a is planted at the center of each side surface of the head holder 5, and each pin 5a has a head pressure spring 27 (tensile spring) whose one end is locked to a side plate (not shown) of the stencil printing machine. The other end of each is locked. Therefore, the thermal head 4 is always biased by the head pressure spring 27 in a direction in which it is pressed against the platen roller 3. Each head pressure spring 2
7, a predetermined biasing force (spring load) is set as described later.

As shown in FIG. 2 or 3, a drive transmission pin 24 is provided at one end of the head holder shaft 6 with a drive transmission pin 24.
Is provided so as to project in the centrifugal direction. Drive transmission pin 2
A head drive worm wheel 28 is provided slidably on the outer side of the head holder shaft 6 that is closer to the inner side than the head drive shaft 4. . A pair of opposing fan-shaped notches 28b are formed in a part of the boss portion 28a, and the head drive worm wheel 28 and the boss portion 28a are formed.
Is provided so as to prevent the drive transmission pin 24 from being displaced in the direction of the head holder shaft 6 so that the drive transmission pin 24 is arranged within the range of the cutout portion 28b. Head drive worm wheel 28
A head drive motor 29 having a head drive worm 30 that meshes with the head drive worm wheel 28 is fixed to the shaft end of the head drive worm 30. The head drive motor 29 is installed in a machine frame (not shown) of the stencil printing machine. It is fixed.

At the other end of the head holder shaft 6, a slit disk 2 having a notch 25a formed in a part of its outer peripheral portion is formed.
5 is fixed. In the vicinity of the other end of the head holder shaft 6, there are disposed transmissive sensors 26 having a light emitting element and a light receiving element on both sides of the slit disc 25, and the transmissive sensor 26 is used in a stencil printing machine. It is fixed to a machine frame (not shown).

From the above, the thermal head contact / separation mechanism 130
Is mainly composed of the head holder 5, the head holder shaft 6, the drive transmission pin 24, the pair of head pressure springs 27, the head drive worm wheel 28, the boss portion 28a, the cutout portion 28b, the head drive worm 30, and the head drive motor 29. Composed.

As will be described later in detail, when the thermal head occupies the first position, the platen roller conveying force generated by pressing the master 1 is the master roll 1R.
The thermal head pressing force can be switched between a third position for holding the thermal head 4 within a range smaller than the platen roller pulling output for pulling out the master 1 and a fourth position for holding the platen roller conveying force larger than the platen roller pulling output. The mechanism doubles as a component of the thermal head contact / separation mechanism 130.

As shown in FIG. 1 or 4, plate making means 11
Below 0, a heater wire 7 as cutting means is arranged. The heater wire 7 extends in a direction traversing the master 1 and is supported and fixed by moving plates 8 having electric insulation at both ends thereof. The heater wire 7 is made of, for example, a nichrome wire whose surface is coated with a fluororesin film such as Teflon (trade name) as a heat-resistant and high-release film, and its both ends are connected to a power supply source (not shown). There is. The moving plate 8 is arranged in a master conveyance path P between the plate making means 110 and a clamper 13 described later in a substantially rectangular shape, and is rotatably mounted on a machine frame (not shown) of the stencil printing machine at its lower end. The moving plate shaft 9 is supported and is attached substantially integrally. A moving plate driving worm wheel 32 is attached to one end of the moving plate shaft 9 substantially integrally. In the vicinity of the moving plate driving worm wheel 32, a moving plate driving worm 34, which meshes with the moving plate driving worm wheel 32, is fixed at its shaft end.
Reference numeral 3 is fixed to a machine frame (not shown) of the stencil printing machine.
A guide plate 10 for switching the transfer of the master 1 to the tray 11 (described later) is fixedly provided on the inner surface on the right side of the movable plate 8 in the figure. The guide plate 10 is formed in a V-shaped cross section so that its lower end overlaps with a tray 11 (described later), and is provided so as to extend in a direction crossing the master 1. The guide plate 10 is made of, for example, an aluminum alloy, and one end surface of the guide plate 10 is coated with a fluororesin film such as Teflon (trade name) as a heat-resistant and high-release film. With the above configuration, the heater wire 7, the moving plate 8,
The guide plate 10 is selectively displaced between the fusing preparation position shown by the solid line in FIG. 1 and the standby position shown by the phantom line by the forward and reverse rotation drive of the moving plate drive motor 33.

At the other end of the movable plate shaft 9, a movable plate slit disk 35 having a notch 35a is fixedly provided. In the vicinity of the other end of the movable plate shaft 9, a transmission type sensor 36 having a light emitting element and a light receiving element on both sides of the slit disk 35 is arranged.

As shown in FIG. 1, in the vicinity of the right side of the movable plate shaft 9 in the drawing, the guide plate 10 is blown by the heater wire 7.
The tray 11 for storing the master cutting waste 31 that is received and guided by the tray is arranged.

In FIG. 1, at the lower left of the plate making apparatus 50, a porous cylindrical support cylinder 12a forming an inner peripheral surface thereof and a mesh wound around the outer peripheral surface of the support cylindrical body 12a. 2 with screen layer (not shown)
A plate cylinder 12 having a layered structure is arranged. The plate cylinder 12 is rotatably supported around a rotation center axis that also serves as an ink pipe shaft 15 described later, and is rotated in the arrow B direction (clockwise direction) and the arrow A direction (counterclockwise direction) by a motor (not shown). Driven.

A part 14 on the outer peripheral surface of the plate cylinder 12 is provided with a magnetic material stage 14 extending parallel to the ink pipe shaft 15, and a pivot 13a provided at one end of the stage 14. And a clamper 13 having a rubber magnet rotatably attached to the pivot 13a and capable of opening and closing with respect to the flat surface portion of the stage 14, respectively. Plate cylinder 1
2, the clamper 13 is stopped in the right lateral direction shown in the figure, that is, at the plate feeding position.

Inside the plate cylinder 12, an ink roller 16 which is rotated in the direction of arrow B in synchronism with the plate cylinder 12 to contact the inner peripheral surface of the plate cylinder 12 to supply ink, and an ink roller 16 and a slight amount. Ink roller 1 is arranged in parallel with a gap.
Doctor roller 17 forming an ink fountain 18 between
And an ink pipe shaft 15 for supplying ink to the ink reservoir 18. The ink roller 16, the doctor roller 17, and the ink pipe shaft 15 form an ink supply device. In the vicinity of the lower portion of the outer peripheral surface of the plate cylinder 12 facing the ink roller 16, a press roller which is selectively swingable and presses in contact with the plate cylinder 12 in synchronism with the feeding of a printing paper (not shown). 21 are arranged.

A sheet feeding device 60 is arranged on the lower right side of the plate making device 50 in the drawing. The paper feeding device 60 includes a pair of registration rollers 23a and 23b for feeding the printing paper 43 between the press roller 21 and the plate cylinder 12 at a predetermined timing.
It is configured by a paper distribution roller 41 that distributes the print paper 43 placed on the paper supply table 40, and a separation roller 42 that presses the paper distribution roller 41 and separates the print paper 43 into one sheet. .

A paper discharging device 70 is disposed on the left side of the drawing as opposed to the paper feeding device 60. The paper discharge device 70 is provided with a paper discharge tray 44 on which printed print sheets (not shown) that have been printed are sequentially stacked, and a print sheet (not shown) that has been printed and is arranged in the vicinity of the outer peripheral surface of the plate cylinder 12. And a peeling claw 22 that is peeled off from 12.

On the left side of the plate cylinder 12 in FIG.
0 is set. The plate discharge device 80 separates the used master (not shown) from the outer peripheral surface of the plate cylinder 12 and the plate discharge box 20 containing the used master (not shown) separated from the outer peripheral surface of the plate cylinder 12. , The plate discharge roller pair to be transferred 19
a and 19b.

(Operation of Embodiment 1) Next, regarding the operation of this stencil printing machine, graphs and FIG. 9 for explaining the relationship between the platen roller conveying force and the platen roller pulling output shown in FIG. 1 to FIG. 6 and FIG. The timing charts shown in (1) and (2) will be described together below. First, the operation at the time of initial setting for setting a new master roll on the plate making apparatus will be described. First, the thermal head contact / separation mechanism 130 operates in FIG. 1 or 2 by sending an opening command from a control device (not shown). That is, the head drive motor 29 is rotationally driven, the rotational force is transmitted to the head drive worm 30, the head drive worm wheel 28, and the boss portion 28a, and the boss portion 28a and the drive transmission pin 24 are moved as shown in FIG. By engaging, the head holder shaft 6 is rotated in the direction of arrow A shown in FIG. 2, and the thermal head 4 is separated from the first position shown in phantom in FIG. Then, the head holder shaft 6 is rotated by the sensor 26 to a position where the notch 25a of the slit disk 25 is ON-detected by a known operation of the light emitting element and the light receiving element (both not shown), and the ON detection signal by the sensor 26 is transmitted. When the thermal head 4 is sent to a controller (not shown) and occupies the second position separated from the platen roller 3 shown by the solid line in FIG. 1,
The rotation drive of the head drive motor 29 is stopped by a stop signal from a control device (not shown).

Simultaneously with the operation of the thermal head contact / separation mechanism 130, an opening command is sent from a control device (not shown), so that the moving plate drive motor 3 shown in FIG.
3 is rotationally driven, the rotational force is transmitted from the moving plate driving worm 34 to the moving plate driving worm wheel 32, and the moving plate shaft 9 is rotated in the direction of arrow A shown in FIG. 8 and the guide plate 10 are separated from the standby position shown in phantom in FIG. Then, the movable plate shaft 9 is rotated by the sensor 36 to a position where the notch 35a of the slit disk 35 is ON-detected by a well-known operation of the light emitting element and the light receiving element (both not shown), and the ON detection signal of the sensor 36 is transmitted. When the heater wire 7, the moving plate 8 and the guide plate 10 occupy the fusing preparation position separated from the standby position shown by the solid line in FIG. 1 after being sent to a control device (not shown), it is moved by a stop signal from the control device (not shown). The rotation drive of the plate drive motor 33 is stopped.

Then, in FIG. 1, the used master roll at the plate making position (shown by phantom lines) is removed from the roll holder, and as shown in FIG. 5, the core tube 1s of the new master roll 1R is attached to the roll holder 2 Roll holder 2b
And press the set key (not shown)
The cam 47 is rotated by the rotation drive of an elevator motor (not shown), and the master roll 1R and the roll holder 2 are displaced to the initial set position (shown by the solid line). After stopping at the initial set position, the leading end of the master 1 is manually pulled out from the master roll 1R, and is inserted so as to hang it down in the space between the thermal head 4 and the platen roller 3 occupying the second position. Thus, as shown in FIG. 1, the tip of the master 1 is
While being in contact with the peripheral surface of the platen roller 3, the platen roller 3 is inserted straight into the space between the thermal head 4 and the platen roller 3, and hangs down straight by its own weight.

After the insertion of the tip of the master 1 is completed, a control device (not shown) issues an unillustrated initial setting completion command to operate the thermal head contact / separation mechanism 130. That is, the head drive motor 29 is rotationally driven in the direction of rotating the head holder shaft 6 in the direction of arrow B in the figure, and the thermal head 4 presses the platen roller 3 via the master 1 to occupy the first position. After the thermal head 4 occupies the first position, the head drive motor 29 is further driven to rotate,
The boss portion 28 of the head drive worm wheel 28 reaches the position of the notch portion 28b where the cutout wall of the boss portion 28a of the head drive worm wheel 28 does not engage with the drive transmission pin 24.
It is stopped by rotating a. Within the range of the cutout 28b, the head holder shaft 6 is slidably rotated until the thermal head 4 gently presses the platen roller 3 via the master 1 by the urging force of the head pressure springs 27. In this way, the thermal head 4 applies the master 1 by the biasing force of the both head pressure springs 27 (more accurately, the force of the thermal head 4 and the head holder 5 plus the load component force of the both head pressure springs 27). It is lightly pressed by the platen roller 3 via.

In FIG. 6, FIG. 8 or FIG. 9, when the thermal head 4 occupies the first position (shown in phantom in FIG. 6), the master 1 is first pressed to generate the platen roller conveying force F1 which is the master roll. The head is pressed by the urging force of both head pressure springs 27 so that the range is smaller than the platen roller pulling output F2 (maximum static friction force of the master roll 1R) that pulls out the master 1 from 1R (the range shown by hatching in FIG. 8). The rotation of the head drive worm wheel 28 is temporarily stopped at a position where the notched wall of the boss portion 28a prevents the holder shaft 6 from slidingly rotating. That is, at this time, the thermal head 4 is lightly pressed by the platen roller 3 via the master 1 to occupy the third position for maintaining the state of F1 <F2. At this time, the master roll 1R and the plate making means 11
The master 1 between 0 and 0 is evenly tensioned over the entire surface of the master 1 within a range in which the master roll 1R does not rotate,
Since the master is stretched uniformly, it is possible to prevent the master 1 from wrinkling.

After the thermal head 4 holds the third position for a predetermined set time Δt1 by a command from a timer of the control means (not shown), the head drive worm wheel is rotated by the head drive motor 29 in FIG. By further rotating 28 in the direction of arrow B, the notch wall of the boss portion 28a of the head drive worm wheel 28 and the drive transmission pin 24 do not engage with each other, the notch portion 28a.
The boss portion 28a of the head drive worm wheel 28 is rotated to the position of b and stopped. Within the range of the cutout portion 28b, the head holder shaft 6 is moved by the thermal head 4 by the biasing force of the head pressure springs 27.
It is slidably rotated until the platen roller 3 is lightly pressed via. At this time, the rotation of the platen roller drive motor 3M is also stopped. Therefore, the thermal head pressing force switching mechanism causes the thermal head 4 to be pressed by the platen roller 3 via the master 1 in the state of plate making, so that the platen roller conveying force F1 is moved to the fourth position larger than the platen roller pulling output F2. Occupy. After that, the rotational drive of the head drive motor 29 is stopped and the plate-making standby state is entered.

On the other hand, while the thermal head 4 is moving to the third position, the heater wire 7 is energized and the heater wire 7 is heated to a predetermined master fusing temperature. Then, the moving plate drive motor 33 drives the moving plate shaft 9 to rotate in the direction of arrow B, whereby the heater wire 7 is displaced from the fusing preparation position shown by the solid line in FIG. 1 to the standby position shown by the phantom line. , The master 1 that hangs straight from between the thermal head 4 and the platen roller 3 that occupy the third position and are in a pressed state
The tip of the is melted. In this way, the melted tip of the master 1 is aligned in parallel with the shaft 3s of the platen roller 3, and the heater wire 7, the moving plate 8 and the guide plate 10 are returned to the standby position, stopped, and moved to the heater wire 7. The energization of is also stopped. Then, as shown in FIG. 1 or 4, the master cutting waste 31 is guided by the guide plate 10 and falls while receiving the tray 11
It is stored inside. Thus, the initial setting is completed.

When the initial setting is completed, an initial setting end command is sent from a control device (not shown), and a lifting motor (not shown) is rotationally driven so as to be displaced to the plate making position (shown by a virtual line) in FIG. 2 and the master roll 1R occupy the plate making position. Next, when the plate making start key is pressed and a plate making command is sent from a control device (not shown), the plate cylinder 12 is rotated in the direction of arrow A by the rotation drive of a motor (not shown) in FIG. The used master (not shown) is rotated by contacting the plate discharge roller 19b to the rear end of the plate discharge roller 19 (not shown).
b and the plate discharging roller 19a, the plate discharging box 20 is peeled off.
It is discarded inside and the plate discharging process is completed. After that, plate cylinder 1
Stops at the plate feeding position shown in FIG. 1, opens the clamper 13 and enters the plate feeding standby state.

The plate making process is started in parallel with the plate discharging process. At the same time, energization of the heater wire 7 at the standby position (shown by a virtual line) is started. After the plate-making standby state in which the thermal head 4 occupies the fourth position, a heating element (not shown) of the thermal head 4 is generated by a digital image signal which is processed and sent by an A / D converter and a plate-making controller both not shown. ) Is selectively heated and the master 1 is selectively melted and begins to be perforated. In this way, the plate-made master (not shown) is conveyed to the downstream side of the master conveyance path P by the rotation and conveyance of the platen roller 3, and the plate-made master (not shown)
Expanded clamper 1 with the tip of the plate waiting for plate feeding
3 and the stage 14 are inserted and clamped. After clamping, the plate cylinder 12 is rotated in the direction of arrow B in FIG. 1 at a peripheral speed substantially the same as the conveying speed of the platen roller 3, so that a master (not shown) that has been prepressed is placed on its outer peripheral surface. It will be wrapped around.

When the conveyance of a master (not shown) which has been prepressed by a certain set amount is completed, the heater wire 7, the moving plate 8 and the guide plate 10 which are energized and heated to a predetermined temperature are moved by the moving plate drive motor 33. 4 is rotated in the direction of the arrow A shown in FIG. 4 to be displaced to the fusing position shown by the solid line in FIG. 1, and the rear end of the plate-making master (not shown) is fused. Then, the rotation drive of the platen roller drive motor 3M is also stopped. Immediately after fusing the rear end of the plate-making master (not shown), energization of the heater wire 7 is stopped, and the heater wire 7, the moving plate 8 and the guide plate 10 are moved by the moving plate drive motor 33.
4 is rotated in the direction of arrow B shown in FIG. 4 to return to the standby position shown in FIG. The plate making is completed when the rear end of the melted and mastered plate (not shown) is completely wound around the outer peripheral surface of the plate cylinder 12.

A master (not shown) that has been prepressed is a plate cylinder 12.
After being wound around the outer peripheral surface of the sheet, so-called plate making step and printing step are started. First, in FIG. 1, the printing paper 43 placed on the paper feed table 40 is separated one by one by the paper distribution roller 41 and the separation roller 42, and one of them is directed toward the registration roller pair 23a, 23b. Be transported. The conveyed printing paper (not shown) is inserted between the plate cylinder 12 and the press roller 21 at a predetermined timing synchronized with the rotation of the plate cylinder 12 by the pair of registration rollers 23a and 23b. Then, the press roller 21 separated from the outer peripheral surface of the plate cylinder 12 moves upward and prints on a plate-making master (not shown) wound around the outer peripheral surface of the plate cylinder 12 rotating in the direction of arrow B. When the paper 43 is pressed, the ink passes from the hole (not shown) of the plate cylinder 12 through the perforated part of the master (not shown) which has been plate-made, and is transferred to the surface of the printing paper (not shown). Printed. At this time, the ink roller 16 also rotates in the same direction as the rotation direction of the plate cylinder 12 to supply the ink to the inner peripheral surface of the plate cylinder 12. Then, the printed printing paper (not shown) is peeled from the outer peripheral surface of the plate cylinder 12 by the peeling claws 22 and discharged to the paper discharge tray 44, and the first printing of the first sheet, that is, so-called printing is completed.
Next, by the same operation as the above operation, a predetermined number of prints are sequentially and continuously performed.

When a very thin master 1 is inserted between the platen roller 3 and the thermal head 4 as in the conventional plate making apparatus, the master 1 is loosened or tilted left and right,
Platen roller 3 with thermal head 4 via master 1
It was not possible to prevent the master 1 from wrinkling when it was pressed against and conveyed by the platen roller 3. On the contrary,
According to the first embodiment, when the thermal head contact / separation mechanism 130 causes the thermal head 4 to occupy the first position from the second position, the thermal head 4 is located between the platen roller 3 and the thermal head 4 at a position above the platen roller 3. While the master 1 is held by the roll holder 2 and the tip of the master 1 is hung and inserted, the master is set straight, so even a very thin master is not loosened or set diagonally, Can be set without wrinkling. Further, at the third position for holding the thermal head 4 by the thermal head pressing force switching mechanism, the master 1 is pressed within a range in which the platen roller conveying force F1 is smaller than the platen roller pulling output F2, so that the entire surface of the master 1 is pressed. After the tension is applied uniformly and the tension is evenly stretched, the thermal head 4 moves to the fourth position where the platen roller conveyance force is larger than the platen roller pulling output, so that the master is uniformly tensioned. Since it is set, there is an advantage that it can be set without wrinkling even if it is inserted in a loose or slanted state.

(Embodiment 2) Another embodiment 2 is shown in FIGS. In the second embodiment, in addition to the structure of the first embodiment, a photo encoder 37 having a well-known structure is attached to the core tube 1s of the master roll 1R, and the photo encoder 37 is sandwiched between the well-known structure. The only difference is that a transmissive sensor 38 is provided.

(Operation of Second Embodiment) Regarding the operation of the second embodiment, only the differences from the first embodiment will be described. When the thermal head 4 occupies the fourth position (shown by an imaginary line in FIG. 7) and the platen roller conveyance force F1 becomes larger than the platen roller pulling output F2, the master roll 1R starts to rotate. The rotation at this time is detected by the sensor 38, and the head drive motor 29 is reversely rotated through a control means (not shown). That is, when the head drive motor 29 is rotated in the reverse direction, the thermal head 4 is moved in the direction in which it is lightly pressed by the platen roller 3 via the master 1, and the master roll 1R maintains the F1 <F2 state in which it does not rotate. Occupies the third position. Then, according to a command from a timer of the control means (not shown), the thermal head 4 holds the third position for a predetermined set time Δt2, and then the thermal head pressing force switching mechanism moves the thermal head 4 in the direction to occupy the fourth position. It

As described above, according to the second embodiment, the platen roller pulling output F depends on the master having a different thickness, the master having a different friction coefficient, or the change of the master roll diameter.
Even if 2 is changed, the thermal head position can be controlled according to the platen roller pulling output F2, and there is an advantage that the master set can be more surely applied with tension evenly and wrinkles do not occur.

The method for displacing the roll holder 2 and the master roll 1R from the plate making position to the initial setting position is not limited to the above-mentioned embodiment, but is carried out by driving a motor such as a stepping motor, or by combining a spring and a solenoid. Alternatively, it may be done manually. Alternatively, one end of the roll holder 2 may be held by a roll holder locking member or the like fixed to the machine frame of the stencil printing machine at the plate making position and the initial setting position, for example, by performing a manual operation. Further, if it is not intended to make the plate making apparatus compact, the roll holder 2 may be held at a position above the platen roller 3 in parallel with the axis 3s direction of the platen roller 3. Further, the holding means is not limited to the roll holder 2 of the above embodiment, but instead of the roll holder 2, for example, for holding the master roll 1R at a position above the platen roller in parallel to the axial direction of the platen roller, It may be a holding member fixed to the machine frame of the stencil printing machine. That is, the holding means described in claim 1 may be any one having a structure for holding the master storage means at a position above the platen roller in parallel to the axial direction of the platen roller.

Further, the operation of switching the pressing of the thermal head 4 against the platen roller 3 from the third position to the fourth position is not limited to the above-mentioned embodiment, but the platen roller drive motor as shown in FIGS. The platen roller 3 may be rotationally driven without turning off the rotation of 3M.

Further, the thermal head contacting / separating mechanism and the thermal head pressing force switching mechanism of the above-described embodiment are not limited, and the thermal head side is fixed and the same contacting / separating mechanism and pressing mechanism as in the above-mentioned embodiment is attached to the platen roller side. A pressure switching mechanism may be provided.

The master storing means for storing the roll-shaped master for heat-sensitive stencil printing according to the second aspect of the invention has a platen roller by means of a roll holder as the holding means as in the structure of the first aspect. It is not necessary to be held parallel to the axial direction of the platen roller at a position higher than the above, and the structure is such that the platen roller can be fed out to a plate making position (shown in FIG. 1) and the like and is rotatably supported. May be.

In this embodiment, the master substantially consisting of the thermoplastic synthetic resin film is used.
It is needless to say that the conventional heat-sensitive stencil master is not limited to this.

[0054]

As described above, according to the first aspect of the present invention, when the thermal head is moved from the second position to the first position by the thermal head contacting / separating mechanism, the leading end of the master serves as the platen roller. Between the thermal head and the master, the tip of the master is hung and inserted by its own weight, and the master is set straight, so even a very thin master will not loosen or be set diagonally,
You can set the master without wrinkling.

According to the second aspect of the present invention, when the thermal head occupies the first position by the thermal head contact / separation mechanism, the platen roller conveyance is performed at the third position where the thermal head pressing force switching mechanism holds the thermal head. By pressing the master in the range where the force is smaller than the platen roller pulling output, tension is applied uniformly over the entire surface of the master so that the platen roller conveyance force is more than the platen roller pulling output. At the large fourth position, the master is set without slack, so the master can be set without wrinkling.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of a stencil printing machine to which an embodiment of the present invention is applied.

FIG. 2 is an enlarged perspective view showing a main part of the plate making apparatus of FIG.

FIG. 3 is an enlarged side view showing a further main part of the plate making apparatus of FIG.

4 is an enlarged perspective view showing a main part around the master cutting means in FIG. 1. FIG.

5 is an enlarged perspective view showing the periphery of the holding means of the plate making apparatus of FIG. 1. FIG. .

FIG. 6 is a schematic side view of an essential part for explaining the operation of the plate making apparatus of FIG.

FIG. 7 is a schematic side view of a principal part for explaining the operation of the plate making apparatus showing another embodiment of FIG.

FIG. 8 is an explanatory diagram for explaining an operation of the plate making apparatus of FIG. 1.

9 is a timing chart for explaining the operation of the plate making apparatus of FIG.

FIG. 10 is a timing chart for explaining the operation of the plate making apparatus showing another embodiment of FIG.

[Explanation of symbols]

P master transport path 1 master for heat-sensitive stencil printing 1s core tube constituting master storing means 2 roll holder as holding means 2b roll holding portion constituting master storing means 3 platen roller 4 thermal head 6 thermal head pressing force switching Head holder shaft 7 that constitutes the mechanism 7 Heater wire as cutting means 24 Drive transmission pin that constitutes the thermal head pressing force switching mechanism 27 Head pressing spring that constitutes the thermal head pressing force switching mechanism 28 Thermal head pressing force switching mechanism Head drive worm wheel 28a Boss portion constituting thermal head pressing force switching mechanism 28b Cutout portion constituting thermal head pressing force switching mechanism 29 Head drive motor 30 constituting thermal head pressing force switching mechanism 30 Thermal head pressing force switching mechanism Head drive Dynamic worm 50 Plate making apparatus 100 Master storage means 110 Plate making means 130 Thermal head contact / separation mechanism

Claims (2)

[Claims] 1. A master storage means for storing a roll-shaped master for heat-sensitive stencil printing, a thermal head for perforating and making the master based on image information, and a downstream of a master transport path while pressing the master against the thermal head. In a stencil printing machine having a plate making means provided with a platen roller for carrying to the side, and a cutting means provided at the downstream side of the master carrying path for cutting the master, wherein the thermal head is A thermal head contacting / separating mechanism for contactably and separably displacing a first position pressed against the platen roller via the master and a second position separated from the platen roller, and the master storing means with the platen roller. And a holding unit that holds the platen roller in parallel with the axial direction at a position above the stencil printing plate. Plate making equipment in the equipment. 2. A master storing means for storing a roll-shaped master for heat-sensitive stencil printing, a thermal head for perforating and making the master based on image information, and a downstream of the master conveying path while pressing the master against the thermal head. In a stencil printing machine having a plate making means provided with a platen roller for carrying to the side, and a cutting means provided at the downstream side of the master carrying path for cutting the master, wherein the thermal head is A thermal head contact / separation mechanism for contactably and separably displacing a first position pressed against the platen roller via the master and a second position separated from the platen roller; and the thermal head having the first position. , The platen roller conveyance force generated by pressing the master causes the master to pull out the master from the master roll. And a third position for holding the thermal head in a range smaller than the pulling output of the roller and a fourth position for switching the pressing force of the thermal head capable of switching between the fourth position where the platen roller conveying force is larger than the pulling output of the platen roller. A plate making apparatus in a stencil printing apparatus, which is characterized in that