JP2000085232A - Stencil printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a wrinkle at a master and to improve a printing performance by providing a suction means for sucking an end of a master via a locking part near a master locking means, in a printer having a plate cylinder which has the locking means having a locking part for locking the end of the master. SOLUTION: When an original is set to an original reader and an engraving start key is pressed, a used master on a plate cylinder 10 is released. Meanwhile an original image read by the reader is converted into an electric signal via a CCD or the like, a master 1 fed from a master roll 1a is conveyed while being engraved by a thermal head 3 and conveyed between a stage 15 and a clamper 16. At this time, an end of the master 1 is sucked by a suction force of a master suction fan 19 provided near a clamper 16. The master 1 is prevented from being slacked or waved, corrected at its curl, effectively held at a clamper 16 while being corrected at its curl, and mounted on an outer periphery of the cylinder 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stencil printing machine for performing printing by winding a master made on a peripheral surface of a plate cylinder.

[0002]

2. Description of the Related Art Conventionally, digital thermosensitive stencil printing has been known as a simple printing method. This is because a heat-sensitive stencil master (hereinafter, referred to as “master”) having a structure in which a thermoplastic resin film and a porous support are bonded to each other has one minute heating element.
The thermal heads arranged in a row are brought into contact with each other, and the master is transported by a transport means such as a platen roller while energizing the heating elements in a pulsed manner. After hot-melt perforating plate making, the perforated plate-making master is wound around a porous cylindrical plate cylinder, and the printing paper is pressed against the outer peripheral surface of the plate cylinder by a pressing member such as a press roller.
The printing image is obtained by transferring the ink that has oozed from the opening of the plate cylinder and the perforation of the master onto the printing paper.

The master used in the digital thermosensitive stencil printing is a thin thermoplastic resin film (thickness 2 to 8).
It has a laminate structure in which a porous support of Japanese paper, synthetic fibers, or a mixture of Japanese paper and synthetic fibers is laminated. For this reason, when the ink oozing from the plate cylinder opening passes through the porous support of the master, there are portions where fibers are intertwined in a complicated manner (dummy portion) or fibers cross the perforation. In such a case, there is a problem in that the transmission is impeded and a fibrous pattern appears in a solid portion, a thin line is cut or faded, and a so-called fibrous grain is generated.

[0004] Therefore, an attempt is made to reduce the problems caused by the fibrous grain by reducing the thickness of the porous support such as Japanese paper, which causes the generation of the fibrous grain, or by printing only with the thermoplastic resin film without using the porous support. Has been made. However, in the conventional master, the porous support bears the apparent strength, and when printing with a master with a thinner porous support or a master consisting of only a thermoplastic resin film, the thermoplastic resin film is only thin. In addition, the strength (waist) of the master is greatly reduced.

[0005] On the outer peripheral surface of the plate cylinder of the stencil printing machine on which the above-mentioned master is wound, a master locking means for holding the leading end of the master is provided. This is composed of a stage portion parallel to the axis of the plate cylinder and a clamper having a locking portion. Each time a new master is wound, the opening / closing member opens and closes the clamper, and clamps the leading end of the master.

Generally, the master is transported to the master locking means by a platen roller, a transport roller, or the like. However, since the plate cylinder rotates when the master is wrapped or printed, collision with the master locking means occurs. In order to avoid the problem, a guide plate or a conveyance roller for guiding the master cannot be provided very close to the plate cylinder.

[0007] For this reason, there is a problem in that the master is wound around the transport roller due to the influence of static electricity or the like before reaching the master locking means from the transport roller at the time of plate making transport, thereby causing a transport failure. Further, even if the master is conveyed without being wound around the roller, the master may be wavy or loose due to shrinkage at the time of punching or the habit of the film, and in this state, when the leading end of the master is pinched by the master locking means,
There is a problem that a wavy portion or a slack portion is crushed during printing and becomes wrinkled, and printing failure occurs. This was more prominent in a master having a thin porous support or a master consisting of only a thermoplastic resin film.

In view of this, a technique has been proposed in which a blowing device for blowing air to the master is provided, and the master is pressed onto the plate cylinder by wind pressure so that even a master having no waist can be pinched by the master locking means without generating wrinkles. It is disclosed in Japanese Patent Publication No. 62-2997.

[0009]

However, the technique disclosed in the above-mentioned publication has a problem in that the tip of the master becomes unsteady due to flutter or the like at the time of blowing, and if the master is clamped as it is, wrinkles are further promoted. is there. Further, the air blow by the blower does not effectively work inside the clamper, and the clamp may become unstable when a curled master is used. Furthermore, when the rear end of the cut master is pulled out from the transport roller and becomes free, the rear end ramps up, making it easier for the master to stick in the form of holding air between it and the plate cylinder. ,
There is a problem that wrinkles occur at the rear end of the master.

The present invention solves the above-mentioned problems, and provides a good master without causing wrinkles even when a master having a thin porous support or a master having no porous support is used. A stencil printing apparatus capable of performing printing is provided.

[0011]

According to the first aspect of the present invention,
In a printing apparatus having a plate cylinder provided with a master locking means having a locking portion for locking a leading end of a master on a part of an outer peripheral surface, in the vicinity of the master locking means, via the locking portion It has a suction means for sucking the tip of the master.

According to a second aspect of the present invention, in the stencil printing apparatus according to the first aspect, the suction means is disposed so as to be able to approach / separate from the master locking means. .

According to a third aspect of the present invention, in the stencil printing apparatus according to the first or second aspect, the suction means is disposed so as to be able to approach / separate from the outer peripheral surface of the plate cylinder. It is characterized by the following.

According to a fourth aspect of the present invention, in the stencil printing apparatus of the first, second or third aspect, the locking portion has a comb-like shape.

According to a fifth aspect of the present invention, in the stencil printing machine according to any one of the first to fourth aspects, the suction means further comprises a suction port for sucking a tip portion of the master. The suction port is provided with a partition member for preventing the master from being sucked into the suction means.

[0016]

FIG. 1 is a schematic diagram of a stencil printing apparatus employing a first embodiment of the present invention. In the figure, a master roll 1a formed by winding a master 1 in which a thermoplastic resin film and a porous support are bonded to each other in a roll shape,
The core 1b is rotatably supported by holder means (not shown).

A platen roller 2 that is driven to rotate clockwise by a stepping motor (not shown) and a thermal head 3 having a number of heating elements are disposed downstream of the master roll 1a in the master transport direction. The thermal head 3 is pressed against the platen roller 2 at a predetermined pressure by a biasing means (not shown) such as a spring.

Platen roller 2 and thermal head 3
A transport roller pair 4 rotatably supported by a main body side plate (not shown) of the stencil printing apparatus is disposed downstream in the master transport direction. The transport roller pair 4 is driven by a driving unit (not shown) in a clockwise direction at a peripheral speed slightly higher than the peripheral speed of the platen roller 2, and is driven by an urging unit (not shown) with a predetermined pressing force. It is composed of a driving roller 4a and a driven roller 4b that rotates together with the driving roller 4a pressed against the roller 4a. With this configuration, a predetermined tension is applied to the master 1 between the platen roller 2 and the transport roller pair 4.

Platen roller 2 and thermal head 3
A cutting means 5 for cutting the master 1 is provided at a position between the feed roller pair 4. Cutting means 5 is upper blade 5
a and a lower blade 5b, and the upper blade 5a moves up and down or rotates with respect to the lower blade 5b to cut the master 1.

A guide plate 6 is provided at a position between the pair of transport rollers 4 and the cutting means 5, and guide plates 7 and 8 are provided downstream of the pair of transport rollers 4 in the master transport direction. Each of the guide plates 6, 7, 8 is fixed to a main body side plate (not shown) of the stencil printing apparatus, and guides the conveyance of the master 1. The above-mentioned platen roller 2, thermal head 3, transport roller pair 4, cutting means 5, each guide plate 6,
The plate making means 9 is constituted by 7, 8 and the like.

At the lower left side of the plate making means 9, there is provided a plate cylinder 10 formed by winding a plurality of layers of a resin or metal mesh mesh screen around a porous support cylinder. The plate cylinder 10 having the opening 10a is fixed to a flange (not shown) rotatably supported on a body side plate (not shown) with the ink pipe 11 as a support shaft, and transmits a driving force from a plate cylinder driving means (not shown). And driven to rotate. The flange (not shown) is detachably provided to the apparatus main body, and the plate cylinder 10 is also detachably provided integrally with an ink pack (not shown).

Inside the plate cylinder 10, an ink roller 12 rotatably supported by a side plate (not shown) fixed to an ink pipe 11 transmits a driving force from a driving force transmitting means (not shown) such as a gear or a belt. Then, it is driven to rotate clockwise. In the vicinity of the ink roller 12, a doctor roller 13 whose outer peripheral surface is arranged close to the outer peripheral surface of the ink roller 12 is disposed in parallel with the ink roller 12. The ink in the ink pool 14, which is supplied in a wedge-shaped section in the vicinity of the ink roller 12 and the doctor roller 13, is stretched when passing through the gap between the ink roller 12 and the doctor roller 13. It is supplied in a thin film on the surface.

On the surface of the non-opening portion of the plate cylinder 10, a stage 15 made of a magnetic material is provided along one generatrix of the plate cylinder 10. On the stage unit 15, the stage unit 1
A clamper 16 is provided as a master locking means whose base end is openably and closably supported by a clamper shaft 16a provided in parallel with 5. As shown in FIG. 2, the clamper 16 has an opening 16b wider than the width of the master 1, and a free end of the opening 16b forms a locking portion 16c for locking the master 1. Opening and closing means (not shown) is connected to one end of the clamper shaft 16a, and the clamper 16 is opened and closed by the opening and closing means when the plate cylinder 10 occupies a predetermined opening and closing position. A switch (not shown) is provided near the clamper 16 to output a signal to a control unit described later when the clamper 16 is closed. Note that, in the present invention, the locking portion 16c is not limited to the shape shown in the drawing, and a portion that substantially locks the leading end of the master 1 is referred to as a locking portion regardless of the shape.

A suction means 17 is arranged on the right side of the plate cylinder 10 in FIG. The suction unit 17 mainly includes a master suction duct 18, a master suction fan 19, and a moving unit 20. The master suction duct 18 made of a thin iron plate, resin, or the like, has one end having a suction port 18a which is an opening bent in a hook shape upward, and the suction port 18a is cut down diagonally downward. The end is closed. The suction port 18a is the opening 1 of the clamper 16.
6b, the plate cylinder 10 is stopped at the open / close position and the clamper 16 is opened when the clamper 16 is opened.
6 is scraped off at an angle substantially equal to the opening angle.
The master suction fan 19 is fixed to the other end of the master suction duct 18, and its operation is controlled by control means described later.

The moving means 20 is mainly composed of a guide member 21, a rack 22, and a drive motor 23, as shown in FIGS. The guide member 21 is attached to a side plate (not shown) of the apparatus main body so as to sandwich both sides of the master suction duct 18, and holds projections (not shown) projecting from both sides of the master suction duct 18. Are movably supported in the left-right direction of FIG.

The rack 22 is attached to the bottom surface of one side of the master suction duct 18. At a position near the rack 22, a drive motor 23, which is fixed to the output shaft and has a pinion 24 meshing with the rack 22, that can be rotated forward and backward, is provided. The drive motor 23 is attached to a main body side plate (not shown), and its operation is controlled by control means described later. Also, two limit switches 38 and 39 (see FIG. 4) are mounted on the movement path of the master suction duct 18, and the master suction duct 18 moves the suction port 18 a shown in FIG. 1 and a second position where the suction port 18a is separated from the clamper 16. The second position is set at a position where the clamper 16 does not interfere with the master suction duct 18 when the plate cylinder 10 rotates after the clamper 16 is closed.

At the lower right of the plate cylinder 10, a well-known registration roller pair 25 for temporarily stopping printing paper fed from a paper feeding device (not shown) and feeding the printing paper after timing is provided.

A press roller 26 having both ends rotatably supported by a press roller arm 26a swingably supported by a main body side plate (not shown) is disposed downstream of the registration roller pair 25 in the sheet transport direction. . The press roller 26 is oscillated by a cam (not shown) or the like, and is provided so that the outer peripheral surface thereof can be freely moved toward and away from the outer peripheral surface of the plate cylinder 10. The press roller 26 is urged toward the plate cylinder 10 by an urging means such as a spring (not shown), and is held at the separated position by a not-shown locking means at the time of separation.

A sheet discharging means 27 is provided downstream of the press roller 26 in the sheet conveying direction. The paper discharging means 27
It is mainly composed of a peeling claw 28, a paper discharge conveyance member 29, and a paper discharge tray (not shown). The peeling claw 28 is supported by a side plate (not shown) of the apparatus main body so that its base end is swingable, and its free end is provided so as to be close to and away from the outer peripheral surface of the plate cylinder 10. Peel off the printing paper stuck on top. The paper discharging and conveying member 29 mainly includes a driving roller 30, a driven roller 31, an endless belt 32, a suction fan 33, and the like. The printing paper is driven while holding the printing paper on the endless belt 32 by the suction force of the suction fan 33. Roller 3
This is a well-known configuration in which print paper is conveyed toward a discharge tray (not shown) with a rotation force of 0.

FIG. 4 is a block diagram of the control means 34 used in the first embodiment of the present invention. CPU, ROM,
The control means 34 composed of a known microcomputer having a RAM and the like is provided on the operation panel 44, a switch (not shown) for detecting that the clamper 16 provided on the clamper 16 is closed, and a moving path of the master suction duct 18. Signals from the two limit switches 38 and 39 are input, and the master suction fan 19 and the drive motor 2
An operation signal is output to the control panel 3 and a data signal is output to the operation panel 44.

The operation of the stencil printing apparatus according to the first embodiment based on the above-described configuration will be described below. When a document is set on a document reading unit (not shown) and a plate making start key (not shown) on the operation panel 44 is pressed, the plate cylinder 10 is rotated by plate cylinder driving means (not shown), and the outer periphery of the plate cylinder 10 is printed by plate discharging means (not shown). The used master wound on the surface is peeled off. The plate cylinder 10 from which the used master has been peeled is stopped by the rotation of the clamper 16 to the plate feeding standby position, which is almost right beside in FIG.

When the plate cylinder 10 stops at the plate feeding standby position, the opening / closing means (not shown) is operated to open the clamper 16, and an operation signal is sent from the control means 34 to rotate the drive motor 23 in the forward direction. The suction duct 18 moves in a direction approaching the clamper 16. Then, when the limit switch 38 is depressed, the operation of the drive motor 23 is stopped, the master suction duct 18 is positioned at the first position shown in FIG. 1, and the stencil printing apparatus enters a plate feeding standby state. At this time, an operation signal is sent from the control means 34, and the master suction fan 19 operates.

A document image read by a document reading unit (not shown) is converted into an electric signal by a CCD or the like. The converted electric signal is sent to the thermal head drive board via an A / D converter, a plate making control device, and the like, and the heating element of the thermal head 3 is energized in a pulse form to generate heat. At the same time, the platen roller 2 and the driving roller 4a are driven to rotate, and the thermoplastic resin film of the master 1 is subjected to heat perforation plate making.

The master 1 conveyed by the platen roller 2 and the conveying roller pair 4 while being made by the thermal head 3 is guided by the guide plates 6, 7, 8 and is moved between the stage 15 and the clamper 16. Conveyed. At this time, the leading end of the master 1 is drawn in by the suction force of the master suction fan 19 operating close to the clamper 16, and the master 1 is prevented from loosening and waving, and is securely pinched by the clamper 16 while curl is corrected ( Locked).

When it is determined from the number of steps of a stepping motor (not shown) that drives the platen roller 2 that the leading end of the master 1 has reached a predetermined position that can be clamped by the clamper 16, the opening / closing means (not shown) of the clamper 16 operates. The end of the master 1 has a stage 15 and a locking portion 16c.
And sandwiched between. When a switch (not shown) detects that the clamper 16 is closed, a command is sent from the control means 34, the operation of the master suction fan 19 is stopped, and the drive motor 23 is rotated in the reverse direction. Due to the reverse rotation of the drive motor 23, the master suction duct 18 moves rightward in FIG. 1, and when the limit switch 39 is depressed, the operation of the drive motor 23 is stopped, and the master suction duct 18 is positioned at the second position. .

When the suction means 17 retreats from the plate cylinder 10,
The plate cylinder 10 resumes rotation at a peripheral speed substantially equal to the master transport speed, and the master 1 after plate-making is wound around the plate cylinder 10. Then, when it is determined from the number of steps of a stepping motor (not shown) that drives the platen roller 2 that plate making for one plate has been completed, the cutting means 5 is operated to cut the master 1, and at the same time, the platen roller 2 and The transport roller pair 4 is stopped. The rear end of the cut master 1 is pulled out by the rotating plate cylinder 10, and the winding of the master 1 around the plate cylinder 10 is completed.

After the winding operation of the master 1 is completed, one sheet of printing paper is fed by paper feeding means (not shown). The printing paper is sent between the plate cylinder 10 and the press roller 26 after being timed by the registration roller pair 25. When the feeding of the printing paper is detected by a sensor (not shown), the locking means (not shown) of the press roller 26 is released, and the press roller 26 is pressed by the urging force of the urging means (not shown) through the printing paper through the outer circumference of the plate cylinder 10. The printed image is transferred to the surface of the printing paper by pressing against the surface. The printing paper on which the image has been transferred is peeled off from the outer peripheral surface of the plate cylinder 10 by the peeling claw 28, conveyed by the paper ejection conveyance member 29, and stacked on a paper ejection tray (not shown).

FIG. 5 is a schematic configuration diagram of a stencil printing apparatus employing a second embodiment of the present invention. The second embodiment differs from the first embodiment in that a suction means 35 is used in place of the suction means 17, a control means 36 is used in place of the control means 34, and limit switches 38 and 39 are used. The only difference is that the limit switches 40 and 41 are used and that an encoder (not shown) for detecting the rotation angle of the plate cylinder 10 is used, and the other configurations are the same.

The suction means 35 mainly comprises a master suction duct 37, a master suction fan 19, and a moving means 20, as shown in FIGS. The master suction duct 37 made of a thin iron plate, resin or the like has a suction port 37a which is an opening at one end, and is closed at the other end. The master suction duct 37 is supported by the moving means 20 so as to be movable in the left-right direction in FIG.

On the moving path of the master suction duct 37, 2
The limit switch 40, 41 (see FIG. 7) is attached, and the master suction duct 37 moves the suction port 37a shown in FIG.
8 and a first position where the suction port 37 a shown in FIG. 8 is close to the outer peripheral surface of the plate cylinder 10. The second position is set to a position where the clamper 16 does not interfere with the master suction duct 37 when the plate cylinder 10 rotates after the clamper 16 is closed. An encoder (not shown) that detects the rotation angle of the plate cylinder 10 is attached to a flange (not shown) that supports the plate cylinder 10.

FIG. 7 is a block diagram of the control means 36 used in the second embodiment of the present invention. Control means 3 including a well-known microcomputer similarly to control means 34
Reference numeral 6 denotes an operation panel 44, an encoder (not shown) provided on the plate cylinder 10, a switch (not shown) for detecting that the clamper 16 provided on the clamper 16 is closed, and a switch 2 provided on the movement path of the master suction duct 37. Signals from the limit switches 40 and 41 are input, and an operation signal is output to the master suction fan 19 and the drive motor 23, and a data signal is output to the operation panel 44.

The operation of the stencil printing apparatus according to the second embodiment based on the above configuration will be described below. When a document is set on a document reading unit (not shown) and a plate making start key (not shown) on the operation panel 44 is pressed, a plate discharging operation is performed as in the first embodiment, and the plate cylinder 10 is moved to the clamper 1.
6 rotates to a plate-supply standby position that is almost right beside in FIG. 5 and stops.

When the plate cylinder 10 stops at the plate feeding standby position, the opening / closing means (not shown) is operated to open the clamper 16, and the stencil printing machine enters a plate feeding standby state. At this time, an operation signal is sent from the control means 36 and the master suction fan 1
9 is activated.

In the plate making means 9, a plate making operation is performed in the same manner as in the first embodiment, and the thermoplastic resin film of the master 1 is subjected to heat perforation plate making. The master 1 conveyed by the platen roller 2 and the conveying roller pair 4 while being made by the thermal head 3 is guided by the guide plates 6, 7, 8 and conveyed between the stage 15 and the clamper 16. . At this time, the leading end of the master 1 is drawn in by the suction force of the master suction fan 19, and the master 1 is guided to a position where the master 1 is securely held by the clamper 16 while curling is prevented while slackening and waving are prevented.

When it is determined from the number of steps of a stepping motor (not shown) that drives the platen roller 2 that the leading end of the master 1 has reached a predetermined position where it can be clamped by the clamper 16, the opening / closing means (not shown) of the clamper 16 operates. The end of the master 1 has a stage 15 and a locking portion 16c.
And sandwiched between. Then, when a switch (not shown) detects that the clamper 16 is closed, a command is sent from the control means 36 and the operation of the master suction fan 19 is stopped.

When the clamper 16 is closed, the plate cylinder 10
Resumes rotation at a peripheral speed substantially equal to the master transport speed, and the master 1 after plate-making is wound around the plate cylinder 10. When it is determined from the number of steps of a stepping motor (not shown) that drives the platen roller 2 that the plate making for one plate has been completed, the cutting means 5 is operated to cut the master 1 and the platen roller 2 and the transport roller Pair 4 is stopped. The rear end of the cut master 1 is the rotating plate cylinder 1.
Derived by zero.

A signal from an encoder (not shown) for detecting the rotation angle of the plate cylinder 10 causes the plate cylinder 10 to rotate approximately three-quarters of a time from the plate feeding standby position, and as shown in FIG.
When the vicinity of the rear end portion 1c of the master 1 wound on the outer peripheral surface of the master 1 reaches the front of the suction means 35, a command is sent from the control means 36, the master suction fan 19 starts operating, and the drive motor 23 Rotates forward, and the master suction duct 37 is positioned at the first position. By being sucked by the suction means 35 operating close to the outer peripheral surface of the plate cylinder 10, the rear end portion 1c of the master 1 is prevented from rampaging, and the master 1 is prevented from wrinkling while being tensioned. , Plate cylinder 10
It is wound neatly on the outer peripheral surface without embracing air.

When a signal from an encoder (not shown) for detecting the rotation angle of the plate cylinder 10 determines that the rear end 1c of the master 1 has passed the front of the suction means 35, a command is sent from the control means 36. Then, the operation of the master suction fan 19 is stopped, and the drive motor 23 rotates in the reverse direction. The master suction duct 37 is positioned at the second position, and the operation of winding the master 1 around the plate cylinder 10 is completed.

After the winding operation of the master 1 is completed, one sheet of printing paper is fed by a paper feeding means (not shown). Sent to between. Then, the locking means (not shown) of the press roller 26 is released, the printing paper is pressed against the outer peripheral surface of the plate cylinder 10, and the print image is transferred onto the surface of the printing paper. The printing paper onto which the image has been transferred is conveyed after being separated from the outer peripheral surface of the plate cylinder 10 by the paper discharging means 27 and stacked on a paper discharging tray (not shown).

As a modification of the above embodiments, a clamper 42 shown in FIG. 9 may be used as the master locking means instead of the clamper 16 as the master locking means. The clamper 42 is supported on the stage 15 by a clamper shaft 42a so as to be openable and closable, and has a locking portion 42b corresponding to the locking portion 16c. The locking portion 42b is combed toward a portion corresponding to the opening 16b. It is formed in a tooth shape. With such a configuration, the leading end of the master 1 sucked by the suction means 17, 35 is moved to the master suction duct 18, 3.
7 can be prevented from being drawn into the interior of the master 1, so that the leading end of the master 1 can be more reliably and neatly held.

Further, as another modified example of each of the above embodiments, the same effect as described above can be obtained by providing fins 43 as partition members at the suction ports 18a, 37a of the master suction ducts 18, 37 as shown in FIG. Can be obtained. In particular,
When the fins 43 are provided in the suction port 37a, the suction of the rear end portion 1c of the master 1 can be prevented.
The winding of the master 1 around 0 can be performed even better. Note that, instead of the fins 43, a mesh member may be used as the partition member.

In each of the above embodiments, the master 1 is made of a thermoplastic resin film bonded to a porous support, but the master 1 is made of a thin porous support or made of only a thermoplastic resin film. Can be used, and in this case, the function and effect of the present invention become more remarkable. The master made of only the thermoplastic resin film referred to here means, in addition to the master made of only the thermoplastic resin film, a master made of a thermoplastic resin film containing a trace component such as an antistatic agent, and a thermoplastic resin. The film includes one or more thin film layers such as an overcoat layer formed on both main surfaces of the film, that is, at least one of the front surface and the back surface.

[0053]

According to the first aspect of the present invention, when the master is locked by the master locking means, the suction means sucks the leading end of the master, so that the master is prevented from loosening or waving, and While the curl is corrected, the guide is guided to a position where the master is securely locked by the master locking means, the master can be locked without wrinkles, and a good printed matter can be obtained.

According to the second aspect of the present invention, since the suction means operates close to the master locking means, the suction efficiency is increased, and the master can be locked more reliably.

According to the third aspect of the present invention, since the suction means is operated close to the outer peripheral surface of the plate cylinder, it is possible to prevent the rear end of the master from being violent, and to prevent the wrinkles from being generated. The master can be wound neatly without entrapping air on the outer peripheral surface of the plate cylinder while giving the image, and a further excellent printed matter can be obtained.

According to the fourth aspect of the present invention, the tip of the master sucked by the suction means is prevented from being drawn into the master suction means, so that the tip of the master can be held more reliably and more clearly. It can be carried out.

According to the fifth aspect of the present invention, the leading end and the trailing end of the master sucked by the suction means are prevented from being drawn into the master suction means, and the front end of the master can be more securely held. In addition, the printing operation can be performed more finely, and the master can be wound around the plate cylinder more satisfactorily.

[Brief description of the drawings]

FIG. 1 is a schematic view of a main part of a stencil printing machine showing a first embodiment of the present invention.

FIG. 2 is a plan view of a clamper used in each of the first and second embodiments of the present invention.

FIG. 3 is a perspective view illustrating a suction unit used in the first embodiment of the present invention.

FIG. 4 is a block diagram of control means used in the first embodiment of the present invention.

FIG. 5 is a schematic view of a main part of a stencil printing machine showing a second embodiment of the present invention.

FIG. 6 is a perspective view illustrating a suction unit used in a second embodiment of the present invention.

FIG. 7 is a block diagram of control means used in a second embodiment of the present invention.

FIG. 8 is a schematic view of a main part of a stencil printing machine for explaining a second embodiment of the present invention.

FIG. 9 is a view for explaining master locking means used in a modification of the first and second embodiments of the present invention.

FIG. 10 is a diagram illustrating a suction port of a suction unit used in another modification of the first and second embodiments of the present invention.

[Explanation of symbols]

 Reference Signs List 1 master 10 plate cylinder 16, 42 master locking means (clamper) 16c, 42b locking portion 17, 35 suction means 43 partition member (fin)

Claims (5)

[Claims] 1. A printing apparatus having a plate cylinder provided with a master locking means having a locking portion for locking a leading end of a master on a part of an outer peripheral surface, wherein the printing apparatus includes A stencil printing machine comprising suction means for sucking the leading end of the master through a stop. 2. The stencil printing apparatus according to claim 1, wherein said suction means is provided so as to be able to approach / separate from said master locking means. 3. A stencil printing apparatus according to claim 1, wherein said suction means is provided so as to be able to approach and separate from an outer peripheral surface of said plate cylinder. 4. The stencil printing apparatus according to claim 1, wherein said locking portion has a comb-teeth shape. 5. The apparatus according to claim 5, wherein said suction means has a suction port for sucking a tip portion of said master, and said suction port is provided with a partition member for preventing suction of said master into said suction means. The stencil printing apparatus according to any one of claims 1 to 4, wherein