JP2000158782A - Printing apparatus and ink supply method for printing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printing apparatus or ink supply method that can effect good printing by solving a short of ink without the occurrence of unnecessary waiting time on ink supply, and reducing the occurrence of density irregularity of a printing image. SOLUTION: The printing apparatus is the one where a punch-processed master 14 is wrapped round the exterior peripheral surface 3a of a form cylinder 3 having a porous support cylinder body being supplied with ink 18 in the interior peripheral surface thereof through the operation of an ink supply means 55 and being rotatable about its central axis, and conducts printing by compressing printing paper 6 against the exterior peripheral surface by a compression member so as to allow ink to run out of an opening part 3b of the form cylinder and punched part of the master 14, in which the operation of an ink supply means 55 is controlled by a control means 60 so that a quantity of ink corresponding to disposed ink stuck onto the disposed master is supplied to an interior peripheral surface of the form cylinder 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus for supplying ink to an inner peripheral surface of a plate cylinder and a method for supplying ink to the printing apparatus.

[0002]

2. Description of the Related Art In a printing apparatus, a rotatable plate cylinder formed by winding a mesh screen of a resin or metal mesh on a porous support cylinder in multiple layers has a thickness of about 1 to 4 mm.
A laminate structure in which a thermoplastic resin film of about 2 μm and a Japanese paper fiber or a synthetic fiber as a porous support, or a mixture of a Japanese paper fiber and a synthetic fiber are laminated, and a plate making means is provided on the film surface. Ink supply means provided inside or outside of a plate cylinder by winding a stencil master formed by heating and perforating a plate by contacting the heat generating elements of a thermal head to be formed and continuously pressing the printing paper with a pressing member. Ink is supplied to the inner peripheral surface of the plate cylinder from the opening portion of the plate cylinder and the perforated portion of the master to perform printing. In such a printing apparatus, the used master wound around the plate cylinder is peeled off by a plate discharging means or by hand, and then the leading end of the newly formed master is clamped by a clamper provided on the plate cylinder to form a plate cylinder. It is wound around the outer peripheral surface.

[0003] Ink used for printing is sent from an ink storage section provided outside the plate cylinder to an ink supply member provided inside the plate cylinder. The ink supplied from the ink storage unit is temporarily stored in a cylindrical ink reservoir formed between an ink roller and a doctor roller that constitute an ink supply member, and then passes through a gap set between the two. Then, the ink is supplied to the surface of the ink roller. The ink in the ink pool is formed into an elongated columnar shape while spreading between the ink roller and the doctor roller while flowing by the rotation of the ink roller, and the size (height) of the column is detected by the ink amount detecting means. It has become.

[0004] In a printing apparatus, a stylus type in which an ink and a stylus are brought into contact with each other is generally used as an ink amount detecting means. Ink is determined to be insufficient due to a signal output from the detection means or when the output is stopped, and ink is supplied. When the stylus and ink come into contact, the ink supply is stopped.

If the ink is supplied while the flow of the ink is unstable, the detection of the amount of ink in the ink pool becomes unstable and the ink may be supplied in a relatively large amount. May be stained. For this reason, the supply of the ink is generally performed during a printing process at a high rotation speed in which the shape of the ink pool rotated and flowed by the ink roller is stable, so that the ink is not run short.

[0006]

The amount of ink used for printing is several to several tens of milligrams per sheet of printing paper, and in rare cases, about several hundred milligrams even in the case of a whole image.
Insufficient ink during the printing process for a single master is unlikely to occur unless under specific conditions such as when printing a large number of sheets. However, several grams of ink are consumed at once in a short period of time in a plate-printing process in which a new plate (plate-made master) is brought into close contact with the outer peripheral surface of a plate cylinder, which is called plate-making. This is because when the used master is discharged and discarded in the plate discharging process, the ink attached to the discharged master is also discarded. For this reason, if the printing of a small number of copies frequently performed is continuously performed, the printing process (printing time) for one plate is shortened, and the ink is supplied to the inner peripheral surface of the plate cylinder. In some cases, the printed image becomes thin, or density unevenness occurs.

[0007] When the ink amount is detected by the ink amount detecting means, the printing operation is stopped until the ink supply is completed so that the supply unevenness does not occur. Invites extension.

The amount of ink discarded together with the master at the time of plate discharging differs depending on the size of the discarded master (the length of the master).

The present invention is directed to a printing apparatus and an ink supply method capable of eliminating insufficient ink without causing unnecessary waiting time for ink supply, reducing the occurrence of density unevenness in a printed image, and performing good printing. The purpose is to provide.

[0010]

SUMMARY OF THE INVENTION The present invention addresses the technical problem of how to solve a temporary ink shortage at the time of printing or printing, and provides ink to the inner peripheral surface of a plate cylinder. This focuses on the supply amount and supply timing.
According to the present invention, an ink is supplied to an inner peripheral surface by an operation of an ink supply unit, and a master perforated and formed on a plate cylinder having a porous support cylinder rotatable around its own central axis is wound around the master. Then, the printing paper is pressed against the outer peripheral surface by a pressing member provided so as to be able to freely contact and separate from the outer peripheral surface of the plate cylinder, and the ink is exuded from the opening of the plate cylinder and the perforated portion of the master to perform printing. It is assumed that the printing apparatus performs the following.

According to the first aspect of the present invention, the master wound around the outer peripheral surface is peeled off from the outer peripheral surface and discarded after the end of the printing performed before the plate discharging, and the first printing performed after the plate discharging is completed. It has control means for controlling the operation of the ink supply means so as to supply to the inner peripheral surface of the plate cylinder an amount of ink corresponding to the ink to be discarded adhered to the discarded master until printing. And For this reason, on the inner peripheral surface of the plate cylinder, an amount of ink corresponding to the ink discarded together with the master by the plate discharge is supplied from the ink supply means from the end of printing to the first printing performed after the plate discharge. Is done.

According to a second aspect of the present invention, the master wound around the outer peripheral surface is peeled from the outer peripheral surface and discarded after the end of printing performed before the plate discharging, and the master is wound around the outer peripheral surface after the plate discharging. Ink is applied so that the amount of ink that adheres to the discarded master and is discarded is supplied to the inner peripheral surface of the plate cylinder by the time the plate is applied, where the printing member applies the printing pressure with the pressing member. It is characterized by having control means for controlling the operation of the supply means. For this reason, an amount of ink corresponding to the ink discarded together with the master by the plate discharge is supplied from the ink supply means to the inner peripheral surface of the plate cylinder between the end of printing and the time of printing.

[0013] The invention according to claim 3 is the invention according to claim 1 or 2.
In the printing apparatus described above, the ink supply means includes: an ink supply driving means for supplying the ink from an ink storage unit containing the ink; an ink supply member provided inside the plate cylinder; an ink supply driving means; An ink transport path connecting the supply member to the supply member; and a control unit controlling a driving operation of the ink delivery driving unit. For this reason, the driving operation of the ink delivery driving means is controlled on the inner peripheral surface of the plate cylinder from the end of printing to the first printing performed after the plate discharge, or from the end of printing to the time of printing. As a result, an amount of ink corresponding to the ink to be discarded is supplied.

According to a fourth aspect of the present invention, in the printing apparatus according to the third aspect, there is provided a master size setting means for setting a size of a master wound around the outer peripheral surface, and the control means comprises a master size setting means. It is characterized by having an ink amount adjusting means for controlling the driving operation of the ink delivery driving means so as to adjust the ink amount supplied to the inner peripheral surface according to the set master size. Therefore, the amount of the ink supplied to the inner peripheral surface of the plate cylinder is adjusted according to the master size.

According to a fifth aspect of the present invention, in the printing apparatus of the third aspect, there is provided a plate making amount detecting means for detecting a plate making amount of the master, and the control means responds to the plate making amount detected by the plate making amount detecting means. And an ink amount adjusting means for controlling the driving operation of the ink delivery driving means so as to adjust the amount of ink supplied to the inner peripheral surface. For this reason,
The amount of the ink supplied to the inner peripheral surface of the plate cylinder is adjusted according to the plate making amount of the master.

According to a sixth aspect of the present invention, there is provided an ink which adheres to a master to be discharged and is discarded before entering a plate discharging step of discharging a master wound on an outer peripheral surface or in parallel with the plate discharging step. An ink supply step of supplying an ink amount appropriate for the above to the inner peripheral surface of the plate cylinder using an ink supply means is performed. For this reason, an amount of ink commensurate with the ink lost by the plate discharge starts to be supplied to the inner peripheral surface of the plate cylinder before the plate is applied.

According to a seventh aspect of the present invention, there is provided an ink supply step of supplying an ink amount corresponding to the ink attached to the master to be discharged and discarded to the inner peripheral surface of the plate cylinder using an ink supply means. The present invention is characterized in that the process is completed before a printing process for performing printing using a master newly wound on the cylinder is started. Therefore, before the printing process starts,
The supply of the ink corresponding to the amount of the discarded ink is completed.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) This embodiment is an example applied to a stencil printing apparatus. In FIG. 1, a stencil printing apparatus includes a stencil unit 1, a plate cylinder 3 around which a master 14 is wound, a press roller 4 as a pressing member, a stencil discharging device 5 as a stencil discharging means, and a paper feed tray 7 for stacking printing paper 6. And a paper discharge transport unit 9 and a paper discharge tray 10 for discharging the printing paper 6 after printing.

The plate making unit 1 includes a master roll 20 formed by being wound in a roll around a core tube 20a.
A support shaft 20b for feeding the master 14, a platen roller 19 for conveying the master 14, and a platen roller 1
Plate making means 8 comprising a thermal head 22 provided so as to be able to freely move toward and away from the plate 9;
A pair of cutter members 21 provided on the downstream side in the sub-scanning direction (hereinafter, referred to as “master transport direction A”) and serving as a cutting unit for cutting the master 14, and the tip 14 of the master 14
a is mainly composed of a plate feed roller pair 23 for sending out a in the master transport direction A and a master guide plate 25.

The platen roller 19 has its shaft rotatably supported, and is rotatably driven by a platen roller drive motor 24 using a stepping motor.
4 is pressed against the thermal head 22 while the master roll 2 is pressed.
It is fed from 0. The thermal head 22 has a plurality of heating elements arranged in a row in the main scanning direction which is the width direction of the master 14 crossing the master transport direction A, and the platen is driven by a well-known contact / separation mechanism (not shown). The roller 19 is provided so as to be able to freely contact and separate. The thermal head 22 selectively heats and pierces the master 14 by heating the appropriate heating element based on an image signal input to the control means 60 described later, and forms a plate-making image according to the image signal. It has a function to do. The operation of the thermal head 22 is controlled by the control means 6.
Controlled by 0. The process from the start to the end of the thermal perforation by the thermal head 22 is defined as a plate making process.

When the stencil printing apparatus includes a well-known exposure scanning system for reading an image of a document optically or a document reading device having a CCD, the master 14 is selected based on an image signal from the document reading device. A plate making image corresponding to the original image is formed by heat-perforation. When the stencil printing apparatus is used as a printer by being connected to an external input / output device such as a personal computer, the master 14 is selectively heated and perforated based on an image signal output from the personal computer to generate an image signal from the personal computer. A corresponding plate-making image is formed. Alternatively, when both functions as a document reading device and a printer are provided, the master 14 may be selectively heated and perforated based on image signals input from the respective devices to form a plate-making image. When a document reading device is provided, an automatic document feeder (ADF) that automatically conveys the document to the document reading unit
May be provided.

The upper cutter member 21 is moved up and down by an eccentric cam 27 rotated by a cutter drive motor 26 to cut the master 14. As the cutter member 21, a guillotine type or a rotary blade moving type (rotary cutter) may be used. The plate feeding roller pair 23 is configured such that one is a driving roller and the other is a driven roller, and is rotated by a plate feeding roller driving unit 65 described later from the time of the plate making process to the end of the plate feeding process. . The master guide plate 25 is fixed between side plates (not shown) and is disposed downstream of the plate feeding roller pair 23 in the master transport direction A, and guides the leading end 14a of the master 14 from below. Therefore, the master 14 is supported by the master guide plate 25 and cut into a desired master size by the cutter member 21. The master size indicates the total length of the master 14 in the master transport direction A.

A plate formed by winding a resin or metal mesh mesh screen on a porous support cylinder having a plurality of openings 3b and a non-opening 3c. The drum 3 is arranged in the master transport direction A. The plate cylinder 3 is rotatably supported with respect to an ink pipe 11 serving as its own central axis. The ink pipe 11 is used for the plate cylinder 3.
Are axially penetrated, and both ends located in the axial direction are respectively supported by side plates of a plate cylinder unit (not shown). The axial direction of the plate cylinder 3 matches the main scanning direction.

The plate cylinder 3 is connected to a plate cylinder drive motor 2 whose speed can be adjusted via a gear train (not shown). In this embodiment, the plate cylinder 3 is driven to rotate counterclockwise. By controlling the rotation speed of the plate cylinder drive motor 2, the plate cylinder 3 discharges a plate,
The control unit 60 controls the rotation speed at the time of plate feeding and plate setting so that the rotation speed is lower than at the time of printing.

Outer peripheral surface 3 located at non-opening portion 3c of plate cylinder 3
A is provided with a stage 12 made of a magnetic material along one generatrix of the plate cylinder 3. In the vicinity of the stage 12, a clamper 13 is supported so as to be openable and closable about a clamper shaft 13a parallel to the stage 12. The clamper 13 is opened and closed at a predetermined position by a closing / closing device (not shown), and grips the tip 14 a of the master 14. The predetermined position in this embodiment is a position where the open / close side of the clamper 13 is opposed to the master guide plate 25, and indicates a position where the clamper 13 is located almost directly above the plate cylinder 3 in FIG. A master 14 is gripped on the outer peripheral surface 3a of the plate cylinder 3 by a clamper 13 at its tip end 14a, and is wound by rotating the plate cylinder 3 at a lower speed than during printing. In this form,
The process from the clamping operation on the leading end 14a of the master 14 to the rotation of the plate cylinder 3 substantially one rotation and the cutting and winding by the cutter member 21 is defined as a plate feeding process.

Inside the plate cylinder 3, an ink roller 15 is provided.
A doctor roller 17 is provided at a slight distance from the outer peripheral surface of the ink roller 15. An ink pool 16 is formed in a wedge-shaped space between the ink roller 15 and the doctor roller 17. The ink roller 15 is rotatably supported between side plates (not shown) by an ink roller shaft 15a, and is rotated and driven in the same direction as the plate cylinder 3 by a well-known gear or belt serving as power transmission means (not shown). You. The ink 18 in the ink pool 16 is
Is formed between the ink roller 15 and the doctor roller 17 while flowing by the rotation of the ink roller 15, so that an appropriate amount necessary for printing passes through the outer peripheral surface of the ink roller 15 to the inner peripheral surface of the plate cylinder 3. Supplied.

The plate cylinder 3 is mounted on a plate cylinder unit (not shown) together with the ink pipe 11. The plate cylinder unit is provided so as to be movable in the direction of the axis of the ink pipe 11 (that is, its own axis) with respect to the printing apparatus main body 28, and is configured to be able to be pulled out from the inside of the printing apparatus main body 28 to the outside. The total length of the plate cylinder 3 in the circumferential direction is JIS
The length is set so that a standard A3 size sheet can be wound in the longitudinal direction. The width of the plate cylinder 3 in the generatrix direction is formed to be longer than the width of the sheet in the main scanning direction when a sheet of JIS A3 size is transported in the longitudinal direction.
The ink pipe 11, the ink roller 15, and the doctor roller 17 constitute an ink supply member 29.

The plate discharging device 5 is disposed on the left side of the plate cylinder 3 in FIG. 1, and is a pair of plate discharging rollers 51 which are driven to rotate while being pressed against each other, and the outer peripheral surface 3a of the plate cylinder 3 by the plate discharging roller pair 51. And a plate discharge box 52 for storing the master 14 to be peeled from the plate. The plate discharge roller pair 51 is provided on the outer peripheral surface 3a of the plate cylinder 3 so as to be able to come in contact with and separate from the plate discharge roller 3 by a moving mechanism (not shown) and a plate discharge drive unit 66 described later. The plate discharge roller pair 51 comes into contact with the outer peripheral surface 3a of the plate cylinder 3 at the time of plate discharge, and the master 14 wound therearound
Is transported to the plate discharge box 52 while holding the rear end between the pair of rollers. At the time of plate discharging, the plate cylinder 3 is rotated at a lower speed than the printing speed, the clamper 13 is also released, and the used master 14 having finished printing is used.
From the outer peripheral surface 3a of the plate cylinder 3 and is discarded. In the present embodiment, the plate discharging roller pair 51 contacts the outer peripheral surface 3a of the plate cylinder 3 to separate the wound master 14 from the outer peripheral surface 3a and store the master 14 in the plate discharging box 52.

Below the plate making unit 1 outside the plate cylinder 3, an ink supply device 30 is provided. The ink supply device 30 includes an ink pack 31 serving as an ink storage unit filled with ink to be refilled, and an ink pump 32 serving as an ink delivery drive unit, the drive operation of which is controlled by a control unit 60, It is attached to the printing device main body 28. One end of the ink pump 32 is connected to the ink pipe 11, and the other end of the ink transport pipe 33, which serves as an ink transport path between the ink pipe 32 and the ink pipe 32, is connected to the discharge side. The other end of a suction pipe 34 whose one end is connected to the ink pack 31 is connected to the suction side of the ink pump 32. With such a configuration of the ink supply device 30, when the ink pump 32 is driven, the ink pack 3
The ink inside 1 is sucked and conveyed into the ink pipe 11 via the ink conveying pipe 33, and is supplied to the ink reservoir 16 from a plurality of supply holes 11 a provided in the axial direction of the ink pipe 11. Ink transfer pipe 33 and ink pipe 11
Is provided so as to be detachable in the axial direction of the ink pipe 11 on one side surface of the plate cylinder 3. These ink supply members 29
And the ink supply device 30 constitute an ink supply means 55. In the present embodiment, the process from the driving of the ink pump 32 to the stop is an ink supply process.

The discharge amount per operation of the ink pump 32, which is the ink supply amount per one time from the ink supply device 30, is, for example, the required ink amount to be replenished to the master 14 wound around the plate cylinder 3. It is set to about 1/10 to 1/2, so that the ink pump 32 is downsized. This is because the viscosity and hardness of the ink vary depending on the type of the ink. Therefore, in order to supply the required amount of ink by a single pump operation, a large discharge force must be used for the ink pump 32. It is because it becomes large. For this reason, in this embodiment, a required amount of ink is supplied to the ink reservoir 16 by operating the ink pump 32 a plurality of times during the ink supply step. That is, about 1/10 to 1/10 of the ink amount corresponding to the used master 14 that is discarded at the time of plate discharging and is discarded.
About 1/2 is the ink supply amount per one time of the ink pump 32. For convenience, in this mode, the supply amount per time is set to 1/5 of the required ink amount.

In this embodiment, the ink supply device 30 and the plate cylinder unit are separately provided. However, the ink supply device 30 is provided on one side plate of the plate cylinder unit, preferably on a side plate located on the front side of the device. They may be provided so as to be movable together in the axial direction. This improves exchangeability when the ink pack 31 is exchanged.

Above the ink reservoir 16, the ink reservoir 1
6 is provided with an ink amount detection sensor 35 serving as an ink amount detection means for detecting the ink amount. The ink amount detection sensor 35 is of a stylus type that detects the amount of ink by coming into contact with the ink 18 in the ink pool 16.
Is turned on and when the contact between the stylus and the ink 18 is lost, it is turned on to output an ink shortage signal.

The press roller 4 is disposed at a position opposed to the ink roller 15 and is provided so as to be able to freely contact and separate from the outer peripheral surface 3a of the plate cylinder 3 by a contact / separation mechanism 36.
The printing unit 50 is formed between the printing cylinder 3 and the outer peripheral surface 3a. The contact / separation mechanism 36 includes a swing arm 38 that is swingably supported by a shaft 37, a tension spring 39 serving as an urging means,
An electromagnetic solenoid 40 serving as driving means. The press roller 4 is rotatably supported at one end of a swing arm 38 and is urged toward the plate cylinder 3 by a tension spring 39.

The electromagnetic solenoid 40 has a movable rod 41 pin-connected to the other end of the swing arm 38. The electromagnetic solenoid 40 is of a pull time type, and is controlled so that the movable rod 41 operates at a timing at which the press roller 4 is separated from the plate cylinder 3 when the clamper 13 passes through the printing unit 50 during a printing step or a printing step. The driving is controlled by the means 60. The electromagnetic solenoid 40 performs a plate discharging process,
During the plate making process and the plate feeding process, the drive is controlled by the control means 60 until each process is completed.

With the structure of the contact / separation mechanism 36, the press roller 4 normally occupies the printing pressure position indicated by the two-dot chain line in FIG. 1, and the clamper 13 passes through the printing section 50 during the plate setting process and the printing process. During the printing, the plate discharging process, the plate making process, and the plate feeding process, the operation is performed so as to occupy the separated position indicated by the solid line.

In this embodiment, the press roller 4 is normally connected to the plate cylinder 3.
However, when the printing paper 6 is not present in the printing unit 50, the press roller 4 and the outer peripheral surface 3a of the plate cylinder 3 come into contact with each other so that the ink is pressed. Therefore, it is preferable to coat the outer peripheral surface of the press roller 4 with a release agent such as a fluororesin. Alternatively, the tension spring 39 and the electromagnetic solenoid 40
May be reversed and the tension spring 39 is set at the normal separated position, and when the printing pressure is required, the electromagnetic solenoid 40 is driven so that the press roller 4 occupies the printing pressure position.

Although the electromagnetic solenoid 40 is used as the driving means of the contact / separation means 36, the plate cylinder driving motor 2 may be used as the driving means, or a driving motor may be provided separately from the driving motor 2. . When a drive motor is used, a cam follower is provided at the other end of the swing arm 38,
A multi-stage cam having a cam surface corresponding to a master size or a paper size is brought into contact with the cam follower, and the multi-stage cam is rotated by a drive motor to press the press roller 4 on the outer peripheral surface 3 of the plate cylinder 3.
It is good to be provided so that it can be freely attached to and separated from a. Alternatively, a plurality of cam members corresponding to the master size and the paper size are provided, the cam members are moved by a variable mechanism (not shown) according to the master size and the paper size, and the drive motor is rotated to move the press roller 4 to the plate cylinder 3. May be provided on the outer peripheral surface 3a so as to freely contact and separate. Instead of the press roller 4, a well-known impression cylinder that is driven to rotate in synchronization with the plate cylinder may be used as the pressing member.

The paper feed tray 7 is arranged on the left side of the press roller 4 in FIG. The printing paper 6 stacked on the paper feeding tray 7 is fed one by one toward the plate cylinder 3 by the separation paper feeding device 42. The separation sheet feeding device 42 is driven to rotate by a sheet feeding driving unit 67 described later. A registration roller pair 43 is disposed between the separation sheet feeding device 42 and the printing unit 50, and the leading end of the plate image formed on the master 14 and the leading end of the printing paper 6 are printed by the printing unit 50.
Is configured to feed the printing paper 6 at the same timing. The paper feed tray 7 has reflection sensors 80a, 80b, 80c, 80d, and 80e constituting a paper size detection sensor 80 serving as a paper size detection means, and a pair of side guides for guiding both ends of the printing paper 6 in the width direction. 8
2 are installed. The side guide 82 has a known configuration that is movable in the width direction of the printing paper 6. The reflective sensors 80b, 80c, 80d, and 80e detect the length of the printing paper 6 in the transport direction (hereinafter, referred to as “paper transport direction B”) indicated by an arrow B, and the reflective sensor 80a The position is detected to detect the length in the width direction of the printing paper 6, and a detection signal is input to the control unit 60. The control means 60 determines the paper size of the printing paper 6 based on the detection signals from the reflection sensors 80a to 80e.

The discharge tray 10 is disposed on the right side (discharge side) of the press roller 4 in FIG. The paper discharge transport unit 9 is arranged between the printing unit 50 and the paper discharge tray 10. The sheet discharging and conveying unit 9 includes the driving roller 4
The suction roller 47 includes a transport belt 46 having a large number of holes formed on the roller 4 and the driven roller 45.
The transport belt 46 is provided so as to be rotated clockwise in FIG. 1 at a peripheral speed higher than the peripheral speed at the time of printing of the plate cylinder 3 by a transport unit drive unit 68 described later. Above the paper discharge transport unit 9, a peeling claw 48 is provided on the outer peripheral surface 3a of the plate cylinder 3 so as to be able to approach and separate from the outer peripheral surface 3a. The peeling claw 48 separates the printing paper 6 stuck to the outer peripheral surface 3a of the plate cylinder 3 due to the viscosity of the ink when passing through the printing unit 50, and guides the printing paper 6 onto the paper discharge transport unit 9.

As shown in FIG. 2, an operation panel 69 is provided on the front of the printing apparatus main body 28. The operation panel 69 has ten keys 7 for inputting numerical information such as the number of prints.
0, a plate making start key 71 for starting a plate making operation, a printing start key 72 for starting a printing operation, a stop key 73 for stopping a printing operation, a power switch key 75 for turning on / off a power supply 74, and an operation state of the stencil printing apparatus. A display section 76 composed of an LCD for display, a counter display section 77 for displaying numerical information such as the number of prints, and a master size key 78 used when selecting a master size are provided.

The control means 60, as shown in FIG.
The main part is constituted by a known microcomputer provided with U61, ROM62 and RAM63.
The CPU 61 has an operation panel 69, a plate cylinder driving motor 2, and a thermal head 2 via an I / O interface 64.
2. Platen roller drive motor 24, cutter drive motor 26, ink pump 32, electromagnetic solenoid 40, plate feed roller drive unit 65, plate discharge drive unit 66, paper feed drive unit 67, transport unit drive unit 68, ink amount detection sensor 35 , A paper size detection sensor 80 is connected.

The ROM 62 has a map 83 serving as a master size setting means for setting the master size in accordance with the operation of the paper size and the master size key 78, and the ink supply by controlling the drive of the ink pump 32 in accordance with the master size. A control program shown in FIG. 4 which serves as an ink amount adjusting means 84 for adjusting the amount, and a diagram for operating each unit in the order of a plate discharging process, a plate making process, a plate feeding process, a plate attaching process, and a printing process as shown in FIG. A basic operation program and a program for driving the ink pump 32 when the ink amount detection sensor 35 is operated due to a shortage of the ink 18 during printing are stored. The ROM 62 stores the operation steps executed by the apparatus when a paper jam or the like occurs during plate discharging or plate feeding and plate feeding is performed again, or when the power switch key 75 is accidentally turned off halfway. It is to be remembered.

The map 83 includes a sheet size detection sensor 80
Is a data corresponding to the master size corresponding to the printing paper 6 or the master size selected by the master size key 78 according to the detection signal from. In this embodiment, this map 8
According to the data of No. 3, the platen roller drive motor 24 is driven and stopped by a predetermined number of steps, and the drive timing of the cutter drive motor 26 is controlled.

The ROM 62 stores data on the number of times the ink pump 32 has been driven according to the master size. This data is obtained in advance by experiments on the number of times the ink pump 32 can be driven so as to supply an ink amount corresponding to the master size, that is, an ink amount corresponding to the ink to be discarded. With reference to the A4 size master 14, a larger amount of ink is supplied for the larger A3 size, and a smaller amount of ink is supplied for the B5 size smaller than the A4 size. I have.

The operation of the stencil printing apparatus having such a configuration will be described. When the plate making start key 71 is pressed and a plate making signal is input, a plate discharging process is executed. In the plate discharging process,
The plate cylinder 3 is rotated counterclockwise at a low speed by the drive of the plate cylinder drive motor 2, the clamper 13 is stopped at a predetermined position facing the master guide plate 25, and the clamper 13 is opened and closed by an opening / closing device (not shown). . Along with this, the plate discharging roller pair 51 rotates and comes into contact with the outer peripheral surface 3a of the plate cylinder 3 so that the used master 14 is sandwiched between the plate discharging box 5 and the plate discharging box 5.
Conveyed toward 2. At this time, since the plate cylinder 3 also rotates counterclockwise, the used master 14 is stored and discarded in the plate discharge box 52 while being peeled off from the outer peripheral surface 3a of the plate cylinder 3. From this plate discharging process to the end of the plate feeding operation, the electromagnetic solenoid 40 is driven to hold the press roller 4 at the separated position.

In the control means 60, a plate making start key 71
Is pressed, the control program of FIG. 4 is started, and the ink supply process is started in parallel with the plate discharging process. In this program, when a prepress signal is input to the control means 60 in step S1, a master size is selected and set in step S2, and the process proceeds to step S3. The master size here determines the size of the printing paper 6 loaded on the paper feed tray 7 from the paper size detection sensor 80, and sets the master size corresponding to the paper size from the map 83. In step S3, the ink pump 3 is set according to the master size.
2 is driven a predetermined number of times, and the ink amount corresponding to the ink to be discarded together with the discarded master 14 is changed to the ink pack 3.
1 to the ink reservoir 16. In this embodiment, the size of the master 14 to be newly made is used as the master size instead of the size of the master 14 to be discharged. However, the size of the newly made master 14 is stored, and this master is stored. The control unit 60 may drive the ink pump 32 by using the master size stored when the plate 14 is discharged as the master size of the discarded master 14.

When the plate discharging process is completed, the plate cylinder 3 is moved to the clamper 1.
3 is stopped until it is positioned almost directly above. When the plate cylinder 3 stops, a closing / closing device (not shown) operates the clamper shaft 13a.
Is rotated, the clamper 13 is released, and a plate-supply standby state is established, and the process proceeds to a plate-making process.

In the stencil making process, if the stencil printing apparatus has a document reading device, the document image
Is converted into an electric signal by an A / D converter and input to the CPU 61 as an image signal.
The two heating elements are energized in a pulsed manner to operate in both main scanning directions. Further, the platen roller drive motor 24 is driven to move the master 14 by the platen roller 19 in the master transport direction A.
While the sheet is being conveyed, the heating film surface of the master 14 is heated and pierced to perform plate making. The master guide plate 25 moves the leading end 14a of the master 14 into the stage 12
And the clamper 13 is followed by the plate feeding process.

In the plate feeding step, when the control means 60 determines from the number of steps of the platen roller drive motor 24 that the leading end 14a of the master 14 has reached the clamper 13, the clamper shaft 13a is rotated by an opening / closing device (not shown). , The clamper 13 is closed and the tip 1 of the master 14 is closed.
While holding the plate 4a by suction, the plate cylinder 3 resumes rotation at substantially the same speed as the master conveyance speed, and the master 14 after plate making is wound. When it is determined from the number of steps of the platen roller drive motor 24 that the plate making is completed, the cutter member 21 is operated and the master 14 is cut, and the platen roller 19 is stopped.
It is pulled out by the rotation of the plate cylinder 3 and the winding around the plate cylinder 3 is completed, and the process shifts from the plate feeding process to the plate attaching process.

In the printing step, one sheet of printing paper 6 is conveyed, fed to the printing unit 50 at a timing by the pair of registration rollers 43, and inserted into the printing unit 50 by a sensor (not shown). Is detected, the drive of the electromagnetic solenoid 40 is stopped. For this reason, the press roller 4 is raised by the urging force of the tension spring 39 and the printing paper 6 is continuously pressed against the master 14, and the printing paper 6 adhered to the master 14 due to the viscosity of the ink is separated by the separation claw 48. The output tray 1
0 is transported and loaded. This printing process allows the master 14
Is sufficiently filled with ink.

When the number of prints is set using the numeric keypad 70 and the print start key 72 is pressed, the printing process starts. In the printing process, the printing paper 6 is fed to the printing unit 50, and the press roller 4 is driven by the driving of the electromagnetic solenoid 40.
, The printing operation is performed in which the printing paper 6 is pressed against the outer peripheral surface 3a of the plate cylinder 3 and the plate image is transferred from the master 14 as an ink image while avoiding the clamper 13 on the plate cylinder 3. It is executed for the number of sheets. The printing paper 6 that has passed through the printing unit 50 is separated from the outer peripheral surface 3 a of the plate cylinder 3 by the peeling claw 48, is sequentially stacked on the paper output tray 10 via the paper discharging conveyance unit 9, and has a set number of printing papers 6. When the printing for is completed, the printing process ends.

When the ink amount sensor 35 detects a shortage of ink in the ink reservoir 16 during the printing process, the ink pump 32 is driven once here to supply the ink consumed by printing as appropriate.

As described above, in the present embodiment, the ink supply step is performed in parallel with the plate discharging step of discarding the used master 14, and the ink pump 32 of the ink supply device 30 is driven. An amount of ink is supplied from the ink pack 31 to the ink reservoir 16 via the ink transport pipe 33 and the ink pipe 11, and is forcibly supplied from here to the inner peripheral surface of the plate cylinder 3 via the ink roller 15. .

In the present embodiment, the ink supply step is performed in parallel with the plate discharge step. However, the ink supply step is performed before the plate discharge step starts (before the used master 14 starts to be separated from the plate cylinder 3). It may be controlled so as to perform. Even if the ink supply process is performed in such an order, an amount of ink corresponding to the discarded ink is supplied from the ink pack 31 to the ink reservoir 16 via the ink transport pipe 33 and the ink pipe 11.
To the plate cylinder 3 via the ink roller 15.
Can be compulsorily supplied to the inner peripheral surface of the main body.

As shown in FIG. 5, the ink supply step is completed at the latest before the printing step is started.
The ink 18 discarded by the plate discharge can be supplied to the inner peripheral surface of the plate cylinder 3, so that a delay in ink supply can be avoided even when a small number of copies are frequently printed, and the printing operation by ink supply during printing can be prevented. Since interruption can be avoided, a good ink supply method is provided.

By terminating the ink supply process before the printing process is started, the master 14 wound on the outer peripheral surface 3a of the printing cylinder 3 can be sufficiently replenished with ink during the printing process. Therefore, a good printed matter can be obtained from the first printing on the printing paper 6 performed in the printing process, and a better ink supply method can be obtained.

In this embodiment, even if a jam occurs at the time of plate discharging or plate feeding and plate feeding is performed again, or even if the power switch key 75 is pressed by mistake during the operation and the power is cut off, Since the process and the presence or absence of the drive of the ink pump 32 are stored, the ink supply process is performed a plurality of times to increase the supply of the ink amount, or the ink supply process is cut and the inner peripheral surface of the plate cylinder 3 is cut. It is possible to prevent the supply of the ink amount from being reduced, and it is possible to reliably supply the set ink amount. For this reason, the ink supply operation is stabilized, and the reliability of the stencil printing apparatus is improved.

(Second Embodiment) The amount of ink consumed during the plate-attaching step varies depending on the master size, but also varies depending on the plate-making amount for the master 14. That is, if the amount of plate making is small and the number of perforated portions of the master is small, the amount of ink consumed in the plate making step is smaller than that of the master 14 having a large amount of plate making and many perforated portions of the master. Second
In this embodiment, the amount of ink supplied to the ink reservoir 16 by the ink supply means 55 is changed in accordance with the amount of plate making. Since the basic configuration of this embodiment is the same as that of the first embodiment, the same components are denoted by the same reference numerals as those of the first embodiment, and detailed description is omitted.

In the second embodiment, as shown in FIG.
61, the thermal head 22 is connected to the plate making amount detecting means 81.
And the control means 60 adjusts the amount of ink supplied to the inner peripheral surface of the plate cylinder 3 in accordance with the plate making amount detected by the plate making amount detecting means 81.
The second embodiment differs from the first embodiment in that a control program shown in FIG. 7 serving as an ink amount adjusting means 85 for controlling the driving operation of the second embodiment is provided instead of the control program shown in FIG.

The plate making amount detecting means 81 is provided with the thermal head 2
The plate making amount is detected from the heat generating locations of each of the heat generating elements in the main scanning direction and the number of times of energization to these heat generating elements. The ROM 62 stores data on the number of times the ink pump 32 has been driven according to the master size. This data is obtained in advance by experiments on the number of times the ink pump 32 can be driven to supply the ink for the master size, that is, the basic ink amount corresponding to the amount of ink to be discarded. When the A4 size master is used as a reference, the basic ink amount is large in the case of the larger A3 size, and the basic ink supply amount is small in the case of the B5 size smaller than the A4 size. The ROM 62 stores a basic plate making amount corresponding to each master size and a map for quantitatively correcting the driving of the ink pump 32 according to the plate making amount of the master 14. Since the steps from the plate discharging step to the printing step in the second embodiment perform the same contents in the same order as in the first embodiment, detailed description will be omitted. The ink supply process in this embodiment is started in parallel with the plate discharging process, and is completed before the plate attaching process.

Hereinafter, the ink supply control will be described with reference to the flowchart of the control program shown in FIG. In this control program, when a plate making signal is input to the control means 60 in step T1, a master size is selected and set in step T2, and the flow advances to step S3 to set a basic ink amount according to the master size. In particular,
The number of times the ink pump 32 is driven according to the master size is set from the map 83.

In step T4, the plate making amount detecting means 81 detects the plate making amount of the thermal head 22 with respect to the master 14, and in step T5, compares the detected actual plate making amount with the basic plate making amount. If the actual plate making amount is smaller than the basic plate making amount in step T5, the process proceeds to step T6 assuming that the ink amount consumed in the plate-making process is smaller than the basic ink amount, and proceeds to step T6. The ink pump 32 is driven in order to reduce the quantity by a fixed amount. In step T5, if the actual plate making amount is not less than the basic plate making amount, it is determined that the basic ink amount is sufficient, and the process proceeds to step T7, where the ink pump 32 is driven to supply the basic ink amount according to the master size, and the processing ends. I do. For this reason, the ink reservoir 16 is supplied with the optimal amount of ink according to the plate making amount of the master 14 by the ink supply unit 55.

In the present embodiment, the size of the master 14 to be newly made is used as the master size, but this master size is stored and used as the master size of the master 14 to be discharged. May drive the ink pump 32.

Since the ink supply step in this embodiment is completed before the printing step is started, sufficient ink is supplied to the master 14 wound on the outer peripheral surface 3a of the printing drum 3 during the printing step. Replenishment is performed. Thereby, even when a small number of copies are frequently printed, the ink supply delay can be avoided, and a good printed matter can be obtained from the first printing on the printing paper 6 performed in the printing process. Further, since the interruption of the printing operation due to the ink supply during printing can be avoided, a good ink supply method is provided.

[0065]

According to the first aspect of the present invention, an amount of ink corresponding to the amount of ink discarded together with the master by the plate discharge is applied to the inner peripheral surface of the plate cylinder from the end of printing to after the plate discharge. Since the ink is supplied from the ink supply unit until the first printing, it eliminates the ink shortage without generating unnecessary waiting time for the ink supply, reduces the occurrence of density unevenness in the printed image, and achieves good printing. I can do it.

According to the second aspect of the present invention, the amount of ink corresponding to the amount of ink discarded together with the master by plate discharging is applied to the inner peripheral surface of the plate cylinder from the end of printing to the time of printing. Since the ink is supplied from the ink supply means in the meantime, it is possible to eliminate the ink shortage without generating an unnecessary standby time required for the ink supply, to reduce the occurrence of density unevenness in the printed image, and to perform favorable printing.

According to the third aspect of the present invention, the inner circumferential surface of the plate cylinder is provided between the end of printing and the first printing performed after the discharge of the plate, or from the end of printing to the time of printing. By controlling the driving operation of the ink delivery driving means, an amount of ink corresponding to the amount of ink to be discarded is supplied, so that the ink shortage can be eliminated without generating unnecessary waiting time required for ink supply. Good printing can be performed by reducing the occurrence of density unevenness in the printed image.

According to the fourth aspect of the present invention, the amount of ink supplied to the inner peripheral surface of the plate cylinder is controlled according to the master size, so that an amount of ink corresponding to the amount of ink to be discarded is discarded. Can be adjusted and supplied in consideration of the master size
Insufficient ink can be eliminated without generating unnecessary standby time required for ink supply, and the occurrence of density unevenness in a printed image can be further reduced to perform favorable printing.

According to the fifth aspect of the present invention, the amount of ink supplied to the inner peripheral surface of the plate cylinder is controlled according to the amount of plate making of the master, so that the amount corresponding to the amount of ink to be discarded. Ink can be adjusted and supplied in consideration of the amount of plate making of the discarded master, eliminating the need for unnecessary waiting time for ink supply, eliminating ink shortage, and reducing the occurrence of density unevenness in printed images. And good printing can be performed.

According to the sixth aspect of the present invention, since an amount of ink commensurate with the ink lost by the plate discharge is started to be supplied to the inner peripheral surface of the plate cylinder before the plate is attached, unnecessary standby for ink supply is started. Insufficient ink can be eliminated without generating time, and the occurrence of density unevenness in a printed image can be reduced, and good printing can be performed.

According to the seventh aspect of the invention, before the printing process is started, the supply of the ink amount corresponding to the discarded ink is completed, so that an unnecessary waiting time for the ink supply is generated. Insufficient ink can be eliminated without any printing, and printing can be performed with reduced density unevenness of the printed image from the first printing in the printing process. Also, since the ink supply period can be extended by the ink supply means, it is not necessary to supply a necessary amount of ink at one time even when the viscosity and the hardness of the ink vary, and the ink supply means can be enlarged. It is possible to reduce the cost of the apparatus by suppressing the temperature.

[Brief description of the drawings]

FIG. 1 is a front view illustrating a schematic configuration of a printing apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view showing a configuration of an operation panel.

FIG. 3 is a block diagram illustrating a configuration of a first embodiment of a control unit.

FIG. 4 is a flowchart of a control program according to a first embodiment of the ink amount adjusting unit.

FIG. 5 is a diagram showing a relationship between each step from a plate discharging step to a printing step and an ink supply step.

FIG. 6 is a block diagram showing a configuration of a second embodiment of the control means.

FIG. 7 is a flowchart of a control program according to a second embodiment of the ink amount adjusting unit.

[Explanation of symbols]

 Reference Signs List 3 plate cylinder 3a outer peripheral surface 3b opening 4 pressing member 6 printing paper 14 master 18 ink 29 ink supply member 31 ink storage unit 32 ink delivery drive unit 33 ink transport path 55 ink supply unit 60 control unit 81 plate making amount detection unit 83 Master size setting means 84, 85 Ink amount adjusting means

Claims (7)

[Claims] An ink is supplied to an inner peripheral surface by an operation of an ink supply means, and a perforated master is wound around an outer peripheral surface of a plate cylinder having a porous support cylinder rotatable around its own central axis. Then, the printing paper is pressed against the outer peripheral surface by a pressing member provided so as to be able to freely contact and separate from the outer peripheral surface, and the ink is oozed out from the opening of the plate cylinder and the perforated portion of the master for printing. In the printing apparatus performing, from the end of printing performed before the plate discharge to separate and discard the master wound around the outer peripheral surface from the same outer peripheral surface, and from the end of the first printing performed after the plate discharging And control means for controlling the operation of the ink supply means so as to supply an amount of ink corresponding to the ink attached to the discarded master and discarded to the inner peripheral surface of the plate cylinder. Printing device. An ink is supplied to the inner peripheral surface by the operation of the ink supply means, and a perforated master is wound around the outer peripheral surface of a plate cylinder having a porous support cylinder rotatable around its own central axis. The printing paper is pressed against the outer peripheral surface by a pressing member provided so as to be able to freely contact and separate from the outer peripheral surface, and ink is exuded from the opening of the plate cylinder and the perforation of the master. In the printing apparatus for performing printing, from the end of printing performed before the plate discharging that separates and discards the master wound on the outer peripheral surface from the same outer peripheral surface and is wound around the outer peripheral surface after the plate discharging. Until the printing press to apply the printing pressure to the master by the pressing member, an amount of ink corresponding to the ink to be discarded adhered to the discarded master is supplied to the inner peripheral surface of the plate cylinder. A control means for controlling the operation of the ink supply means. A printing device comprising a step. 3. The printing apparatus according to claim 1, wherein said ink supply means is provided inside the plate cylinder, and an ink delivery drive means for delivering the ink from an ink storage section containing the ink. A printing apparatus, comprising: an ink supply member, and an ink conveyance path connecting the ink supply drive unit and the ink supply member, wherein the control unit controls a driving operation of the ink supply drive unit. . 4. The printing apparatus according to claim 3, further comprising master size setting means for setting a size of a master wound around said outer peripheral surface, wherein said control means is set by said master size setting means. A printing apparatus comprising: an ink amount adjusting unit that controls a driving operation of the ink delivery driving unit so as to adjust an amount of ink supplied to the inner peripheral surface according to a master size. 5. The printing apparatus according to claim 3, further comprising plate making amount detecting means for detecting a plate making amount of a master, wherein said control means controls the inner periphery in accordance with the plate making amount detected by said plate making amount detecting means. A printing apparatus comprising: an ink amount adjusting unit that controls a driving operation of the ink delivery driving unit so as to adjust an amount of ink supplied to a surface. 6. An ink supply means is supplied to the inner peripheral surface by ink supply means, and a perforated master is wound around the outer peripheral surface of a plate cylinder having a porous support cylinder rotatable about its own central axis. Printing is performed by pressing printing paper against the outer peripheral surface with a pressing member provided so as to be able to freely contact and separate from the outer peripheral surface so as to exude ink from the opening of the plate cylinder and the perforation of the master. In the printing apparatus, before or before the plate discharging step of discharging the master wound on the outer peripheral surface, or in parallel with the plate discharging step, the amount of ink corresponding to the ink attached to the plate discharged master and discarded. An ink supply step of supplying the ink to the inner peripheral surface of the plate cylinder using the ink supply means. 7. A perforated master is wound around an outer peripheral surface of a plate cylinder having an inner peripheral surface supplied with ink by ink supply means and having a porous support cylinder rotatable about its own central axis, Printing is performed by pressing printing paper against the outer peripheral surface with a pressing member provided so as to be able to freely contact and separate from the outer peripheral surface so as to exude ink from the opening of the plate cylinder and the perforation of the master. In the printing apparatus, an ink supply step of supplying an ink amount corresponding to the ink attached to the master to be discharged and discarded to the inner peripheral surface of the plate cylinder using the ink supply means is newly added to the plate cylinder. A printing process for performing printing using a master wound around the printing apparatus before the printing step is started.