JPH079750A - Plate making device of screen printing machine - Google Patents

Abstract

PURPOSE:To provide a screen printing machine capable of detecting even the presence of a transparent master composed of substantially only a thermoplastic resin film. CONSTITUTION:A master storage means 1a storing a master 1, a thermal head 2 selectively perforating the master 1 corresponding to image data under heating, a platen roller 3 feeding the master l while pressing the same to the thermal head 2, a cutting means 5 cutting the master 1 and a detection means 7 consisting of a light emitting element 7a and a light detecting element 7b detecting the presence of the master 1 are provided. A detection part forming means 26 forming the mark detected by a detection means 7 at the position being the unprinted image area of the master 1 and corresponding to the detection means when the master 1 is passed through the detection means 7 is provided so as to freely approach and separate with respect to the mask 1.

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 printing by winding a master punched with a heating element such as a thermal head.

[0002]

2. Description of the Related Art Digital thermal stencil printing has been known as a simpler printing method. This is because the master is contacted with a thermal head in which fine heating elements are arranged in a line,
By conveying the master while energizing the heating element in a pulsed manner, the heat-melting perforation is performed based on the image information, and then the ink is passed through the perforated portion and transferred to the printing paper to form a printed image. It is like this.

In a master conventionally used for stencil printing, as a detecting means thereof, for example, Jpn.
As disclosed in Japanese Patent Laid-Open No. 5 (1999), an index consisting of perforations or notches is formed on a master wound in a roll shape at intervals that gradually expand or contract, and this index is used by a transmissive photosensor. There is known a technique of detecting, or a technique of detecting a paper piece attached to a master or a mark printed on the master by using a reflective photosensor. By detecting the presence / absence of the master in this manner, it is determined whether or not the master is jammed in the plate making path, and the start of printing is displayed on the control panel.

[0004]

The above master has a laminated structure in which a thermoplastic resin film and a porous support such as synthetic fiber or Japanese paper are bonded together. for that reason,
In the area where the Japanese paper fibers are entangled with each other, the transmission of the ink is obstructed, and a so-called fiber grain problem occurs in which the ink is not transferred to the paper and a fiber pattern is formed in a solid portion, fine lines are cut or faint. Therefore, it has been attempted to reduce the defects due to the fiber grain by printing using a master substantially consisting of a thermoplastic resin film without using a support.

However, unlike the conventional master having a laminated structure, in the master substantially consisting of the thermoplastic resin film, since the master is transparent, the technique for detecting the change in the amount of passing light disclosed in the above publication and The technology for detecting the reflected light on the master surface cannot be used, and the master cannot be detected.

[0006]

The invention according to claim 1 is
A master storage means for storing the master wound in a roll shape, a thermal head for selectively heating and punching the master according to image information, and a platen roller for transporting the master while pressing the master against the thermal head, In a plate making apparatus of a stencil printing machine having a cutting means for cutting the master and a detecting means composed of a light emitting / receiving element for detecting the presence or absence of the master, when the master passes through the detecting means, It is characterized in that a detecting portion forming means for forming a detected mark detected by the detecting means is provided at a position corresponding to the detecting means in the print image area so as to be able to come into contact with and separate from the master.

According to a second aspect of the present invention, master storing means for storing the master wound in a roll shape, a thermal head for selectively heating and punching the master according to image information, and the master for the thermal In a plate making apparatus of a stencil printing apparatus having a platen roller that conveys while pressing against a head, a drive roller that is rotatably disposed downstream of the platen roller in the master conveyance direction, and rotates so as to come into contact with the drive roller. It is characterized by having a driven roller freely provided and a detection means for detecting a change in the rotational speed of at least one of the drive roller and the driven roller.

According to a third aspect of the present invention, in the first aspect of the present invention, the detection section forming means is further provided upstream of the cutting means in the master conveyance direction, and the detection section forming means is provided on the master. After forming the detected mark, the cutting unit cuts the master so as to divide the detected mark into two parts.

[0009]

According to the first aspect of the present invention, the detecting portion forming means forms a detected mark in the non-image area of the master, and the detecting means detects the detected mark.

According to the second aspect of the present invention, the detecting means detects a change in the rotational speed of at least one of the driving roller and the driven roller, and the master conveyed from the master conveying means is bitten by the driving roller and the driven roller. Make sure that.

According to the third aspect of the invention, the cutting means cuts the master so as to divide the formed detected mark into two parts, and the detected mark is provided at the front end and the rear end of the cut master. They are formed at the same time.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic side view of the essential parts of a stencil printing machine adopting the first embodiment of the present invention.

In the figure, reference numeral 10 indicates a plate making apparatus. The plate making apparatus 10 mainly includes a master storage means 1a, a thermal head 2, a platen roller 3, a cutting means 5, a detecting means 7, a detecting portion forming means 26 and the like.

The master 1 consisting essentially of a thermoplastic resin film wound into a roll is the master storage means 1
It is rotatably supported by a.

On the left side of the master 1, a thermal head 2 for selectively heating and punching the master 1 based on the input image information is arranged.

Below the thermal head 2, a platen roller 3 is arranged to convey the master 1 while pressing the master 1 against the thermal head 2. The platen roller 3 is rotatably supported by a support shaft 3a, and is rotationally driven by a stepping motor (not shown).

On the downstream side of the thermal head 2 and the platen roller 3 in the master conveying direction, a cutting means 5 composed of an upper blade 5a and a lower blade 5b is arranged.

A guide plate 6 for guiding the conveyance of the master 1 is fixed to the stencil printer main body downstream of the cutting means 5 in the master conveyance direction. As shown in FIG. 2, the guide plate 6 has an end 6a on the upstream side in the master conveyance direction bent downward so that the master 1 can be easily introduced, and an opening 6b is formed near the end 6a. .

At a position facing each other with the guide plate 6 in between, a detecting means 7 including a light emitting element 7a and a light receiving element 7b is provided. In the detection means 7, the optical axis emitted from the light emitting element 7a passes through the opening 6b of the guide plate 6 and the light receiving element 7b.
Is arranged at a position to reach.

An auxiliary roller 8 is rotatably supported by a support shaft 8a above the guide plate 6 and downstream of the detection means 7 in the master conveying direction, and the outer peripheral surface of the auxiliary roller 8 contacts the guide plate 6. It is arranged as follows. Auxiliary roller 8
Are driven to rotate by a motor (not shown).

Below the master storage means 1a, a detection portion forming means 26 is arranged. The detection portion forming means 26 is
The detection unit forming member 27, the arm 28, the solenoid 29, the sensor 30, and the like are mainly configured.

As shown in FIG. 3, the detecting portion forming member 27 is composed of a roller 31 and an ink box 32. The roller 31 is formed of an elastic body such as rubber. The ink box 32 has a box shape, and ink containing a volatile solvent soaked in felt or sponge is stored in the ink box 32. Ink box 3
The upper surface 1 of the roller 2 is open, bearing portions 32a, 32a are formed perpendicular to the open surface, and a roller 31 is pivotally mounted on the supporting shaft 33, and the outer surface of the roller 31 is It is loosely fitted with the open surface. A seal member 34 is provided at the fitting portion between the roller 31 and the ink box 32, the roller 31 and the ink box 32 are kept airtight, and the roller 31 is slidably rotatable. The roller 3 on one side of the ink box 32
One end 28a of the arm 28 is fixed to one side of the rotational direction 1 of the arm 1.

The arm 28 is a plate material, and its substantially central portion is rotatably supported by a central shaft 35 fixed to the main body of the stencil printing apparatus. The other end 28b of the arm 28 located on the opposite side of the one end 28a fixed to the ink box 32,
The tip end of the plunger 29a of the solenoid 29 is engaged with the engagement pin 36 at a position approximately in the middle of the position supported by the central shaft 35. Further, one end of a tension spring 37 is fixed to an intermediate position between the position supported by the central shaft 35 and the position where the engagement pin 36 engages with the plunger 29a. It is fixed to the stencil printer body. By the urging force of the tension spring 37, the arm 28 is urged by the stopper 38 fixed to the main body of the stencil printing apparatus when the solenoid 29 is not operated.

The solenoid 29 is fixed to the main body of the stencil printing machine and operates by receiving a signal from a control device (not shown).

A sensor 30 fixed to the main body of the stencil printing machine is arranged near the solenoid 29. As shown in FIG. 4, the sensor 30 is provided at a position where the other end 28b can be detected when the arm 28 is attracted by the solenoid 29 and rotated.

A plate cylinder 11 made of a porous cylinder is rotatably supported on the lower left side of the plate making apparatus 10 by a support shaft 12 which also serves as an ink supply pipe. The plate cylinder 11 has an opening 11a on the outer peripheral surface thereof and is rotationally driven by a plate cylinder driving means (not shown).

The plate cylinder 11 also has locking means 16 composed of a stage portion 14 and a clamper 15 on the outer peripheral surface thereof. The stage portion 14 is a flat portion provided in parallel with the generatrix of the plate cylinder 11, and the master 1 is placed on the upper surface thereof.
The clamper 15 is rotatably supported by a support shaft 15a pivotally mounted on the outer peripheral surface of the plate cylinder 11, and when the plate cylinder 11 is stopped at a locking position described later, an opening / closing means (not shown). ), The master 1 placed on the stage unit 14 is sandwiched and held on the outer peripheral surface of the plate cylinder 11.

Inside the plate cylinder 11, the ink roller 1
8, an ink supply unit 20 including a doctor roller 19 and the like is provided. The ink roller 18 is rotatably arranged so that its outer peripheral surface is in contact with the inner peripheral surface of the plate cylinder 11, and the doctor roller 19 has a slight gap between its outer peripheral surface and the outer peripheral surface of the ink roller 18. It is arranged above the ink roller 18 so as to have a gap. The ink supplied from the plurality of apertures formed on the surface of the support shaft 12 drops into a wedge-shaped space formed by the outer peripheral surface of the ink roller 18 and the outer peripheral surface of the doctor roller 19 to form an ink pool 21. . The ink in the ink reservoir 21 is supplied to the outer peripheral surface of the ink roller 18, and the ink roller 18 supplies the ink on the outer peripheral surface thereof to the inner peripheral surface of the plate cylinder 11.

A plate discharging means 22 is arranged on the left side of the plate cylinder 11. The plate discharging means 22 includes an upper plate discharging roller 23,
It is mainly composed of a lower plate discharging roller 24, a plate discharging box 25 and the like. The upper plate discharging roller 23 and the lower plate discharging roller 24 are both rotationally driven by a driving unit (not shown),
The lower plate discharge roller 24 is rocked by a rocking means (not shown), and is provided so as to be able to come into contact with and separate from the outer peripheral surface of the plate cylinder 11.

Next, the operation of the first embodiment will be described. When a plate making start command is output from a control device (not shown), the plate cylinder driving means rotationally drives the plate cylinder 11 to stop the plate cylinder 11 at the locking position shown in FIG. Next, the opening / closing means rotates the clamper 15 of the locking means 16 in the counterclockwise direction to release the holding of the master of the previous plate wound on the outer peripheral surface of the plate cylinder 11.

When the clamper 15 is opened, the plate cylinder driving means is activated, and the plate cylinder 11 has the rear end portion of the master of the previous plate wound around the outer peripheral surface thereof and the rear plate discharging roller 24 of the plate discharging means 22. Move to the plate ejection position corresponding to and stop. Then, the lower plate discharge roller 24 is driven to rotate counterclockwise and the upper plate discharge roller 23 is rotated to rotate clockwise.
The plate cylinder driving means is actuated again to rotate the plate cylinder 11 in the clockwise direction, and at the same time, the swinging means (not shown) brings the lower plate discharge roller 24 into contact with the outer peripheral surface of the plate cylinder 11.
Through this series of operations, the master of the previous plate wound around the outer peripheral surface of the plate cylinder 11 is wound up by the lower plate discharge roller 24 from the rear end and discarded in the plate discharge box 25, and the plate discharge is completed.

After the completion of plate discharge, plate supply is started. Plate cylinder 11
Is rotationally driven by the plate cylinder driving means and is again positioned at the locking position shown in FIG. When the plate cylinder 11 is positioned at the locking position and the clamper 15 is opened to enter the plate making standby state, the platen roller 3 and the auxiliary roller 8 of the plate making apparatus 10 are rotationally driven by the stepping motor and the motor in synchronization with each other. . The master 1 is conveyed while being pressed against the thermal head 2 by the platen roller 3, and the thermal head 2 selectively heat-melts and punches the master 1 based on the input image information to make a plate.

The master 1 made by plate making is conveyed by the platen roller 3, passed through the cutting means 5, and then conveyed to the guide plate 6. The master 1 conveyed on the guide plate 6 comes into contact with the auxiliary roller 8 before being conveyed to the locking means 16 by the auxiliary roller 8. When it is determined from the step number of the stepping motor that the tip of the master 1 has reached the predetermined position of the locking means 16, a command is output from the control device, and the rotations of the stepping motor and the motor are stopped at the same time. After that, the opening / closing means is activated to rotate the clamper 15 in the clockwise direction, and the tip of the master 1 is held between the clamper 15 and the stage portion 14.

When the locking means 16 clamps the leading end of the master 1, a command is output from the control device, and the plate cylinder driving means, the stepping motor, and the motor are simultaneously rotated in synchronization, and the outer peripheral surface of the plate cylinder 11 is rotated. The master 1 made by plate making is wound.

As the winding operation progresses, the master storage means 1 will eventually come out.
The rear end portion of the master 1 wound around the outer peripheral surface of the plate cylinder 11, that is, the cutting position cut by the cutting means 5, approaches the portion of the outer surface of the master 1 stored in a corresponding to the roller 31. When the control device judges from the step number of the stepping motor, a signal is sent from the control device, and the solenoid 29 is energized based on the signal. When the solenoid 29 is energized, the plunger 29a of the solenoid 29 is attracted to pull the arm 28 and pull the spring 3
The roller 31 is rotated counterclockwise around the central shaft 35 against the urging force of the roller 7 to bring the roller 31 into contact with the outer surface of the master 1. Then, the ink roller 31 rotates with the master 1 in the counterclockwise direction. Master 1 at this time
The ink stored in the ink box 32 is adhered to the outer surface of the sheet by the roller 31 to form a detected mark 39. As shown in FIG. 5, the distance that the roller 31 is in contact with the master 1 crosses the cutting line 40 of the master 1 by the cutting means 5, and the detected mark 39 is provided at the rear end and the front end of the master 1. Is set to form.

From the number of steps of the stepping motor,
When the control device determines that the detected mark 39 has been formed for the set length, a signal is sent from the control device, and the solenoid 29 is de-energized based on the signal. Then, the arm 28 is urged by the tension spring 37 and the stopper 38 is urged.
And is positioned at the initial position shown in FIG.

When the control device determines from the step number of the stepping motor that the master 1 has been wound on the outer peripheral surface of the plate cylinder 11 for a predetermined length as the winding further proceeds, the plate cylinder driving means, the stepping motor, The motors stop, and the cutting means 5 cuts the master 1. At this time, the detected mark 39 is located on the cutting line 40, as shown in FIG.

After that, the plate cylinder rotates, and the detection means 7 detects the detected mark 39 at the rear end of the master 1. It is confirmed that the master 1 is not jammed in the conveyance path, and the next plate is attached. It is possible to start the process.

In the above embodiment, when the master 1 stored in the master storing means is running low, as shown in FIG. 4, the other end 28b of the arm 28 crosses the sensor 30 so that the sensor 30 is actuated and the control panel is placed. The master roll replacement will be displayed.

FIG. 6 is a schematic side view of the essential parts of a stencil printing machine adopting the second embodiment of the present invention. In the figure,
The same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

In this embodiment, the plate making device 41 includes a master storage means 1a, a thermal head 2, a platen roller 3, a cutting means 5, a driving roller 42 and a driven roller 43.
It is mainly composed of etc.

On the downstream side of the cutting means 5 in the master conveying direction,
A guide plate 44 that guides the master 1 made into a plate to the locking means 16 is provided. The guide plate 44 is a plate material, which is fixed to the main body of the stencil printing apparatus and has a plurality of holes.

Above the guide plate 44, there is arranged a finely divided drive roller 42 which is mounted on the drive roller shaft 42a. One end of the drive roller shaft 42a is rotatably supported by the main body of the stencil printing machine, and the other end of the drive roller shaft 42a is joined to a motor 45 for rotating the same through a torque limiter 46 as shown in FIG. There is.

Below the drive roller 42, a driven roller 43, which is in the shape of a slice, is disposed so as to correspond to the drive roller 42. The driven roller 43 has its outer peripheral surface
The driven roller shaft 43a is attached to the driven roller shaft 43a so as to face the conveyance path through a plurality of openings provided in the guide plate 44 and to contact the outer peripheral surface of the drive roller 42 and the outer peripheral surface of itself. The driven roller shaft 43a is rotatably supported by the main body of the stencil printing machine, and the driven roller 43 is configured to rotate together with the drive roller 42. As shown in FIG. 8, a slit plate 47, which is a disk notched evenly, is fixed near one end of the driven roller shaft 43a, and a detection means for detecting the notch of the slit plate 47 is provided in the vicinity thereof. The sensor 48 is provided. The sensor 48 is fixed to the main body of the stencil printing apparatus.

Next, the operation of the second embodiment will be described. When the plate discharge is completed by the same operation as in the first embodiment, the plate supply is started. The plate cylinder 11 is rotationally driven by the plate cylinder driving means and is positioned at the locking position shown in FIG. When the plate cylinder 11 is positioned at the locking position and the clamper 15 is opened to enter the plate-making standby state, the platen roller 3 and the drive roller 42 of the plate-making device 41 start rotating at the same time. At this time, the rotation speed of the motor 45 is set such that the peripheral speed of the outer peripheral surface of the drive roller 42 is higher than the peripheral speed of the outer peripheral surface of the platen roller 3. The master 1 is conveyed while being pressed against the thermal head 2 by the platen roller 3, and the thermal head 2 selectively heat-melts and punches the master 1 based on the input image information to make a plate.

The master 1 made by plate making is conveyed by the platen roller 3 and, after passing through the cutting means 5, the guide plate 44.
Be transported to. Master 1 conveyed on the guide plate 44
Eventually comes into contact with the drive roller 42 and the driven roller 43. At this time, since the speed at which the drive roller 42 winds the master 1 is higher than the speed at which the platen roller 3 sends out the master 1, tension is applied to the master 1 between the drive roller 42 and the platen roller 3, and the drive roller shaft 42a A torque change occurs. Then, this torque change causes the torque limiter 46 to slip, and the rotation speed of the drive roller 42 decreases. As the rotation speed of the drive roller 42 decreases, the rotation speed of the driven roller 43 also decreases. By the sensor 48 detecting the change in the rotation speed at this time,
The control device determines that the master 1 is present in the transport passage. (See FIG. 9) After that, the master 1 is conveyed to the locking means 16 by each roller. When it is determined from the step number of the stepping motor that the tip of the master 1 has reached the predetermined position of the locking means 16, a command is output from the control device, and the stepping motor and the motor 4
The rotation of 5 stops at the same time. After that, the opening / closing means is activated to rotate the clamper 15 in the clockwise direction, and the tip of the master 1 is held between the clamper 15 and the stage portion 14.

When the locking means 16 clamps the leading end of the master 1, a command is output from the control device, and the plate cylinder driving means, the stepping motor, and the motor 45 are simultaneously rotated in synchronization, and the outer peripheral surface of the plate cylinder 11 is rotated. Master 1 made by
To wind up. When the control device determines from the step number of the stepping motor that the master 1 is wound on the outer peripheral surface of the plate cylinder 11 for a predetermined length, the plate cylinder driving means, the stepping motor, and the motor 45 are stopped, respectively, and the cutting means. 5 cuts the master 1 to complete the plate feeding.

In the second embodiment, the driven roller shaft 4 is used.
Although the slit plate 47 is provided on 3a, the slit plate 47 may be provided on the drive roller shaft 42a.

In the above-described embodiment, the sensor 48 detects the change in the rotation speed of the driven roller 43, so that the master 1
The control device determines that the master 1 is present in the transport passage. However, when the change in the current value of the motor 45 due to the change in the rotation speed of the drive roller 42 is detected, the master 1 is present in the transport passage. It is also possible to adopt a configuration in which the control device determines that the

The master used in the above examples, which is substantially composed of a thermoplastic resin film, means that the master is composed only of the thermoplastic resin film, and that the thermoplastic resin film contains trace components such as an antistatic agent. In addition, those containing a single layer or a plurality of thin film layers such as an overcoat layer are formed on both main surfaces of the thermoplastic resin film, that is, at least one of the front surface and the back surface.

[0051]

According to the first aspect of the present invention, the detection portion forming means forms the detected mark in the non-image area of the master,
Since this detection mark is detected by the detection means, even a transparent master consisting essentially of a thermoplastic resin film,
The presence or absence thereof can be detected, and it is possible to judge whether or not the master has jammed in the transport path and to confirm that the master has been transported to a predetermined position.

According to the second aspect of the present invention, the detecting means detects a change in the rotational speed of at least one of the driving roller and the driven roller, and the master conveyed from the master conveying means is bitten by the driving roller and the driven roller. It is possible to judge that the master is present and confirm the presence / absence of the master in the transport path.

According to the third aspect of the present invention, the cutting means cuts the master so as to divide the formed detected mark into two parts, and the detected mark is provided at the front and rear ends of the cut master. Since they are formed at the same time, the detected mark can be formed on the front end portion and the rear end portion of the master in one step.

[Brief description of drawings]

FIG. 1 is a schematic side view of a main part of a stencil printing apparatus adopting a first embodiment of the present invention.

FIG. 2 is a perspective view illustrating a first embodiment of the present invention.

FIG. 3 is a partial perspective view illustrating a detection portion forming member of the present invention.

FIG. 4 is a partial schematic side view illustrating the first embodiment of the present invention.

FIG. 5 is a partial perspective view illustrating the first embodiment of the present invention.

FIG. 6 is a schematic side view of a main part of a stencil printing apparatus that employs a second embodiment of the present invention.

FIG. 7 is a diagram illustrating a second embodiment of the present invention.

FIG. 8 is a diagram illustrating a second embodiment of the present invention.

FIG. 9 is a diagram illustrating a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 master 1a master storage means 2 thermal head 3 platen roller 5 cutting means 7 detection means 7a light emitting element 7b light receiving element 10 plate making device 26 detection unit forming means 39 detected mark 42 drive roller 43 driven roller 48 detection means (sensor)

Claims (3)

[Claims] 1. A master storage means for storing a master wound in a roll shape, a thermal head for selectively heating and punching the master according to image information, and a conveyance while pressing the master against the thermal head. In a plate making apparatus of a stencil printer having a platen roller for cutting, a cutting unit for cutting the master, and a detection unit including a light emitting / light receiving element for detecting the presence or absence of the master, when the master passes the detection unit. A detection section forming means for forming a detected mark detected by the detection means is provided at a position corresponding to the detection means in a non-printed image area of the master so as to be capable of contacting and separating from the master. A plate making apparatus for a stencil printing machine, characterized by: 2. A master storage means for storing a master wound in a roll shape, a thermal head for selectively heating and punching the master according to image information, and a conveyance while pressing the master against the thermal head. In a plate making apparatus of a stencil printing apparatus having a platen roller for driving, a driving roller rotatably disposed downstream of the platen roller in the master transport direction, and a driven roller rotatably provided so as to come into contact with the driving roller. A plate making apparatus for a stencil printing apparatus, comprising: a roller; and a detection unit that detects a change in the rotational speed of at least one of the drive roller and the driven roller. 3. The detecting section forming means is provided on the upstream side of the cutting means in the master conveying direction, and after the detecting section forming means forms the detected mark on the master, the cutting means forms the detected mark. The plate making apparatus for a stencil printing apparatus according to claim 1, wherein the master is cut so as to divide the detection mark into two parts.