JP2002036704A - Stencil printing device and printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a waste of ink by collecting the usable ink adhered to a master to be discharged and returning it to a plate cylinder. SOLUTION: A plate discharging device 48 is provided with plate discharging rollers 50a, 50b, 50c for stripping off a used master 23 from a plate cylinder 2, an ink scraping means 51 for scraping an ink adhered to the master 23, and an ink collection roller 53 as an ink collection means for returning the ink scraped by the ink scraping means 51 to the plate cylinder 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stencil printing apparatus and a printing method for performing printing by leaching ink from a stencil sheet (hereinafter, referred to as "master") and transferring it to printing paper.

[0002]

2. Description of the Related Art In a stencil printing machine, a stencil master is wound around a porous and cylindrical rotatable plate cylinder, and a sheet is continuously pressed against the plate cylinder by a pressing means such as a press roller. Ink is supplied from the ink supply means inside the plate cylinder and oozes out from the opening (porous area) of the plate cylinder and the perforated part of the master to perform printing. The plate cylinder has a configuration in which a mesh screen of a resin or metal mesh is wound on a porous support cylinder body in a single layer or a multi-layer. The master is formed in a laminate structure in which a thermoplastic resin film having a thickness of about 1 to 3 μm is laminated with a Japanese paper fiber, a synthetic fiber, or a mixture of a Japanese paper fiber and a synthetic fiber as a porous support. The master plate making is performed by melting and perforating the master surface while making contact with a heating element of a thermal head driven based on information of a document image, and is called a thermal digital system.

Generally, a fully automatic stencil printing apparatus for automatically performing plate making, printing, and plate discharging is used. In the stencil printing apparatus of this fully automatic type, a document of an image to be printed is set on a reading device and read by a scanner unit of the reading device. In the scanner unit, the density of an image is converted into an electric signal by a CCD or the like. Based on the read information, the master is pierced by a plate making device provided with a thermal head, a platen roller, and the like, and the master, which has been made, is automatically wound around a plate cylinder. The paper fed from the paper feeding device is continuously pressed against the plate cylinder by the pressing means, and the ink supplied from the inside of the plate cylinder oozes out of the opening of the plate cylinder and the perforated portion of the master by the pressing, and Transfer and printing is performed.

In the case where there are a plurality of originals, when printing of a predetermined number of sheets by the master corresponding to one original is completed, the used master wound around the plate cylinder is peeled off by the plate discharging device, and the next sheet is removed. A master made on the basis of image information of a document is wound around a plate cylinder. Each time a predetermined number of prints are completed, the plate discharging and plate feeding operations are repeated. The plate discharging device has a plate discharging box for accommodating a stripped-off master. The master contained in the plate discharging box is compressed and stored by a reciprocating pressing plate, and is discarded when it is full. ing.

[0005]

If the master is left for a long time while being wound around the plate cylinder, water evaporates and the viscosity of the ink decreases, but such ink is unsuitable for reuse. Absent. Incidentally, a large amount of ink adheres to the used master that has been peeled off from the plate cylinder, and there are not a few reusable inks. In the case of a plurality of originals, a plurality of masters are peeled off from the plate cylinder within one working time as described above, but the ink adhering to these masters is not deteriorated with time and is At a level suitable for use.

However, conventionally, such reusable ink has been discarded together with the master. For this reason, the ratio of the actual use amount to the ink supply amount is low, and waste of ink has been a problem. In addition, since the ink supply amount is large, the number of replacements of ink packs for supplying ink from the outside of the plate cylinder to the ink supply means inside the plate cylinder also increases, and there is a problem that the replacement operation is troublesome.
In addition, since the master to which ink has adhered is stored in the plate discharge box, the occupied volume is larger than in the case where only the master is used, and there is a problem that the storage capacity of the plate discharge box is reduced by the volume of ink. Further, since the weight of the ink is added in addition to the weight of the master, there is a problem in that the labor for removing and discharging the plate discharge box increases.

Accordingly, an object of the present invention is to provide a stencil printing apparatus and a printing method capable of reusing the ink relating to the stencil discharge and eliminating the above problems.

[0008]

To achieve the above object, according to the first aspect of the present invention, there is provided a stencil printing apparatus having a stencil discharging device for removing used stencil paper from a plate cylinder and storing the stencil. A stencil discharging means for detachably removing the used stencil sheet from the plate cylinder, and an ink scraper for scraping ink adhering to the used stencil sheet. Means and an ink collecting means for returning the ink scraped by the ink scraping means to the plate cylinder.

According to a second aspect of the present invention, in the stencil printing machine according to the first aspect, the ink scraping means includes a blade which transfers the ink scraped by contacting the used stencil sheet to the stencil discharging means. And a contact / separation mechanism for selectively positioning the blade at a contact position and a retracted position.

According to a third aspect of the present invention, in the stencil printing apparatus according to the second aspect, a configuration is adopted in which a contact pressure of the blade against the stencil sheet is variably provided via elastic force. .

According to a fourth aspect of the present invention, in the stencil printing apparatus of the first aspect, the ink collecting means has an ink collecting roller which can be freely attached to and detached from both the plate discharging means and the plate cylinder. , Is adopted.

According to a fifth aspect of the present invention, in the stencil printing apparatus of the fourth aspect, the plate discharging means has a pair of plate discharging rollers for peeling the used stencil sheet from the plate cylinder. One of the plate discharging rollers is provided so as to be movable with respect to the other plate discharging roller, and the one plate discharging roller constitutes the ink collecting means together with the ink collecting roller at the moved position.

According to a sixth aspect of the present invention, in the stencil printing machine according to the fifth aspect, the one plate discharging roller forms an ink reservoir with the ink collecting roller at a moved position, and the ink collecting roller forms the ink collecting roller. It functions as a doctor roller for making the amount of ink returned from the roller to the plate cylinder substantially uniform.

According to a seventh aspect of the present invention, in the stencil printing apparatus according to the sixth aspect, a lock means for fixing the position of the one plate discharging roller at the moved position is adopted.

According to the invention described in claim 8, claims 4 to 7 are provided.
In the stencil printing apparatus according to any one of the above, the ink collecting roller has a cam configuration for avoiding interference with a convex portion of the plate cylinder between the ink collecting roller and the plate cylinder. It has a configuration.

In the ninth aspect of the present invention, the first to eighth aspects are provided.
The stencil printing apparatus according to any one of the above, further comprising an ink state judging means for judging the degree of temporal deterioration of the ink adhering to the used stencil sheet, and the ink state judging means reuses the ink. When it is determined that the printing operation is not possible, a normal plate discharging operation is performed without scraping and collecting the ink.

According to a tenth aspect of the present invention, in the stencil printing apparatus according to the ninth aspect, there is provided a stencil printing apparatus, wherein the ink state determining means determines the ink state based on the idle time counted by the time measuring means. , Is adopted.

According to an eleventh aspect of the present invention, in the stencil printing machine according to the ninth aspect, there is provided an environmental state detecting means for detecting an environmental state, and the ink state determining means is configured to detect the environment detected by the environmental state detecting means. The ink state is determined based on the state.

In the twelfth aspect of the present invention, a stencil sheet made by stencil is wound around the outer peripheral surface of the plate cylinder, ink is supplied from the inside of the plate cylinder, and printing paper is pressed against the outer peripheral surface of the plate cylinder. In the printing method in which ink is leached from the stencil sheet to perform printing, the ink adhering from the used stencil sheet peeled off from the plate cylinder is scraped, and the collected ink is applied to the surface of the plate cylinder. It is designed to be returned and reused for the next printing.

According to a thirteenth aspect of the present invention, in the printing method according to the twelfth aspect, the state of the ink adhering to the used stencil sheet is determined, and if it is determined that the ink cannot be reused, the ink is removed. The used stencil sheet is discharged as it is without being collected.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. First, an overall configuration of a stencil printing apparatus according to the present embodiment will be described with reference to FIG. As shown in FIG. 1, the stencil printing apparatus includes a plate cylinder 2 rotating in the direction of an arrow 29, and a stencil master 2 wound around the outer peripheral surface of the plate cylinder 2.
A plate-making / plate-supplying device 22 for supplying the printing paper 3, a plate discharging device 48 for peeling the used master 23 from the plate cylinder 2,
4, a press roller 70 as a pressing unit for pressing the fed printing paper 34 against the plate cylinder 2, and a separation claw 3 for separating the printing paper 34 from the plate cylinder 2.
9, a paper discharge conveyance device 61 that suctions and conveys the printed printing paper 34 separated from the plate cylinder 2, a paper discharge table 40, and the like.

A clamper 28 for holding the leading end of the master 23 is provided on the outer peripheral surface of the plate cylinder 2, and is opened and closed at a predetermined timing by opening and closing means (not shown). Plate cylinder 2
Is provided with an ink supply means 38. The ink supply means 38 includes an ink roller 75 that supplies ink to the inner peripheral surface of the plate cylinder 2, a doctor roller 77 that forms an ink reservoir 76 between the ink roller 75, and the plate cylinder 2 as an ink supply pipe. And a distribution pipe 78 for dropping ink from a rotating shaft (not shown) to the ink reservoir 76. Ink is supplied to the rotation shaft of the plate cylinder 2 from an ink pack (not shown) provided outside the plate cylinder 2.

In the plate making / plate feeding device 22, an unprinted master 23 is wound around a core material (not shown) and provided in a roll shape. The master 23 is pressed against a platen roller 79 rotatably supported by a plate making unit side plate (not shown) by a heating surface of a thermal head 80 having a large number of heating elements. The platen roller 79 is rotated clockwise by a stepping motor (not shown). Driven out of the roll state. Although not explicitly shown, the master 23 has a laminate structure in which a thermoplastic resin film having a thickness of about 1 to 3 μm is laminated with a Japanese paper fiber or a synthetic fiber as a porous support or a mixture of a Japanese paper fiber and a synthetic fiber. Is formed. Thermal head 80
Are urged by a spring member (not shown), and this is a pressing force against the platen roller 79.

On the downstream side of the platen roller 79 in the master transport direction, a pair of feed rollers 81 having a transport speed higher than the transport speed of the platen roller 79 is rotatably supported by a plate making unit side plate (not shown) while being pressed against each other. A predetermined tension is applied to the master 23 while sliding with the master 23. This feed roller pair 14, 14
A cutter 82 for cutting the master 6 at a position of a predetermined length is provided between the platen roller 79 and the platen roller 79. The master 23 that has been made is temporarily accommodated in the slack box 83, and its leading end is sent to the clamper 28 at a predetermined timing by the plate feeding roller pair 84 during plate feeding.

The paper feeding device 3 includes a paper feeding table 33 on which printing papers 34 can be loaded and lifted, a paper feeding roller 35 for feeding out the top one of the printing papers 34, and a printing paper fed by the paper feeding rollers 35. It has separation rollers 36a and 36b for separating the paper 34 one by one, and a pair of registration rollers 37 for feeding the printing paper 34 to a transfer portion at a predetermined timing. The press roller 70 is rotatably supported by an arm (not shown), and is controlled so as to selectively contact the plate cylinder 2 when the printing paper 34 is fed. Paper discharge transport device 61
Is a conveyor belt 41 having ventilation holes and a suction fan 42
have.

The plate discharging device 48 includes a plate discharging roller 50 as a plate discharging means for peeling the used master 23 from the plate cylinder 2.
a, 50b, 50c, an ink scraping means 51 for scraping ink adhered to the used master 23, and an ink collecting means for returning the ink scraped by the ink scraping means 51 to the plate cylinder 2. The ink recovery roller 53,
It has a plate discharge box 49 and the like for accommodating the stripped master 23 (claims 1 and 12).

The plate discharge rollers 50a, 50b, 50c are provided as a single unit so as to be able to freely move toward and away from the plate cylinder 2 by a moving motor 117 (FIG. 5). As shown in FIG. 2, the plate discharging roller 50a is a plate discharging roller raising / lowering motor 58.
And an L-shaped frame 85 so as to be able to move up and down. A pinion 86 is fixed to the rotating shaft 58 a of the plate discharge roller lifting motor 58, and the pinion 86 meshes with a rack (not shown) formed on the vertical piece 85 a of the frame 85. The rotating shafts of the plate discharging rollers 50b and 50c are supported by a side plate (not shown). An L-shaped opening 88 is formed in the side plate, and the rotating shaft 89 of the plate discharging roller 50a passes through the opening 88. ing. A vertically extending shaft 90 is fixed to a rotation shaft 89 of the plate discharging roller 50a, and an upper end of the shaft 90 is engaged with a stay 59 fixed to a side plate (not shown). A spring 91 is wound around the shaft 90, and the rotation shaft 89 of the plate discharging roller 50 a is always positioned at the vertical portion 88 a of the opening 88. The plate discharge roller 50a is moved by the frame 85 pushing up the rotating shaft 89 in the opening 88. The plate discharging roller 50a that has moved upward constitutes ink collecting means together with the ink collecting roller 53 (claim 5). Plate discharge roller 50
b is rotated by a plate discharge roller drive motor 121 (FIG. 5).

An ink collection roller elevating motor 71 is fixed to the ink collection roller 53, and a gear 92 is fixed to a rotating shaft 71 a of the ink collection roller elevating motor 71. A gear 93 meshes with the gear 92,
The gear 93 is engaged with a rack (not shown) formed on a frame 94 fixed to a side plate (not shown). With this configuration, the ink recovery roller 53 can be moved up and down (claim 4). The ink collecting roller 53 is brought into pressure contact with the plate cylinder 2 by a printing pressure solenoid 116 (FIG. 5).

As shown in FIG. 3, a lock means 95 is provided near the stay 59 for fixing the position of the plate discharge roller 50a at the moved position. The lock means 95 has a lock solenoid 72 fixed to the side plate 96 and an arm 98 pivotally supported by a bracket 97 for fixing the position of the stay 59. One end of the arm 98 is connected to the movable rod 72 a of the lock solenoid 72, and the other end of the arm 98 is connected to the shaft 9.
A U-shaped hook 99 that engages with the zero is provided. At the other end of the arm 98, a spring 100 for returning the arm 98 to the original position is locked. The stay 59 is formed with a long hole 59a extending along the horizontal portion 88b (FIG. 2) of the opening 88.

As shown in FIG. 4, the ink scraping means 51
Has a blade 54 for transferring the ink scraped by contacting the used master 23 to the plate discharging roller 50a, and a contact / separation mechanism 102 for selectively positioning the blade 54 at a contact position and a retreat position. (Claim 2). The contact / separation mechanism 102 includes a squeegee solenoid 103, an arm 105 swinging about a positioned shaft 104 as a fulcrum, and a bracket 106 rotatably connected to the arm 105.
And a frame 107 fixed to the bracket 106
A blade holder 108 slidably provided on the frame 107; and a master 23 of the blade 54.
And a spring 109 for adjusting the contact pressure with respect to the elastic force. One end of the arm 105 is connected to the movable rod 103a of the squeegee solenoid 103. The movable rod 103a returns to the original position by the urging force of the spring 110.

Pins 1 are provided at both ends of the blade holder 108.
08a is fixed, and the frame 1
A long hole (not shown) for guiding the 08a in the vertical direction is formed. With this configuration, the blade holder 108 can be positioned in the roller axis direction and can be vertically displaced. At both ends of the ink collecting roller 53, cam rollers 112 which constitute one of the cam configurations for avoiding interference with the clamper 28 as a convex portion of the plate cylinder 2 are provided. Correspondingly, a cam (not shown) is provided on the plate cylinder 2 side. Interference with the clamper 28 is avoided by displacement caused by the cam roller 112 getting over the cam.

FIG. 5 shows a control configuration according to the present embodiment. The printing operation of the stencil printing apparatus described above is controlled by the control unit 115. The control means 115 is a CPU,
It is a microcomputer including a ROM, a RAM, an I / O interface, and the like, and also functions as an ink state determining unit. The control unit 115 receives information from a timer 118 as a time measuring unit, detection information from a temperature sensor 119 and a humidity sensor 120 as an environmental state detecting unit, and the like (claims 10 and 11). The control means 115 controls the plate discharge roller raising / lowering motor 58, the squeegee solenoid 103, the ink collecting roller raising / lowering motor 71, the lock solenoid 72, the printing pressure solenoid 116, the moving motor 117 and the like based on these information.

Next, the printing operation of the above-described stencil printing apparatus will be described. When a document is set on a document reading unit (not shown) and a start signal is issued by pressing a start button or the like, the control unit 115 moves the plate cylinder 2 to the home position based on information from a home position detection sensor (not shown). Drive motor (not shown). When the plate cylinder 2 is at the home position, the drive motor is stopped. Next, the used master 23 is peeled off from the surface of the plate cylinder 2 by the plate discharging device 48 while the plate cylinder 2 is rotated by the drive motor. The plate cylinder 2 rotates and stops until the clamper 28 is at a position almost directly above. When the plate cylinder 2 stops, the clamper 28 is opened by an opening / closing device (not shown), and the plate feeding standby state is established. The heating element of the thermal head 80 is energized in a pulsed manner based on the image information of the document reading section, and the thermal head 80 operates in the main scanning direction. Further, a stepping motor (not shown) rotates, and the master 23 is moved by the platen roller 79 and the feed roller pair 81.
Is transported in the sub-scanning direction, and the thermoplastic resin film of the master 23 is heated and perforated to perform plate making.

The tip of the master 23 is guided to the clamper 28. If it is determined from the number of steps of a stepping motor (not shown) that the leading end of the master 23 has reached the clamping portion of the clamper 28, the clamper 28 is closed by an opening / closing device (not shown), and the leading end of the master 23 is clamped. 2 resumes rotation at substantially the same speed as the master transport speed, and the master 23 after plate making is wound. When it is determined from the number of steps of a stepping motor (not shown) that the plate making is completed, the cutter 82 is operated to cut the plate-made master 23 and to release the platen roller 79.
And the feed roller pair 81 are stopped, the cut master 23 is pulled out by the rotation of the plate cylinder 2, and the winding around the plate cylinder 2 is completed.

When the printing of the master 23 having been made on the plate cylinder 2 is completed, one sheet of printing paper 34 is separated and fed from a sheet feeding device 3 (not shown), and the registration roller pair 37 sets the timing to set the printing paper 34. 2 to the transcription site. When paper feeding of the printing paper 34 is detected by a paper detecting unit (not shown),
The locking means (not shown) is released, and the press roller 70 rises to continuously press the printing paper 34 against the plate cylinder 2. As a result, the wound master 23 comes into close contact with the plate cylinder 2, and the printing paper 34 is peeled off by the separation claws 39, and
The paper is conveyed at 8 and discharged to the paper discharge table 40. By this test printing operation, the wrapped stencil-made master 23 is stencil-filled with ink, and the press roller 70 is separated and returns to the initial position, and is in a printing standby state. Thereafter, a predetermined number of prints are made.

Next, the plate discharging operation by the plate discharging device 48 will be described with reference to FIG.
This will be described in detail based on the flowchart of FIG. When the plate discharging start signal is output by the control means 115, the moving motor 117 is driven, and the plate discharging roller section (the plate discharging roller 50) is driven.
a, 50b, 50c) move toward the plate cylinder 2 as shown in FIG. 7 (S1). Then, the plate discharge roller drive motor 1
21 is driven to apply a rotational force to the plate discharging roller 50b. A gear or friction force (not shown) is applied to the plate discharge roller 50c.
The plate discharge roller 50b is applied to the plate discharge roller 50a by frictional force.
Is transmitted (S2). As shown in FIG. 7, the plate cylinder 2 is rotated by the rotation of the plate discharge roller 50b.
Of the used master 23 released from the clamper 28 is pinched between the plate discharging rollers 50a and 50b and peeled off.

The leading end of the master 23, which is pinched between the plate discharging roller 50 a and the plate discharging roller 50 b and peeled off, is subsequently pinched between the plate discharging roller 50 c and the plate discharging roller 50 b, and is conveyed toward the plate discharging box 49. Is done. A master detection sensor 55 is provided near the downstream of the plate discharge roller 50c and the plate discharge roller 50b in the transport direction, and the control unit 115 checks whether the master detection sensor 55 detects the leading end of the master 23 (S3). ). When the leading edge of the master 23 is detected, the plate discharge rollers 50a, 50
The rotation of b and 50c is stopped (S4), and as shown in FIG. 8, the moving motor 117 is driven to return the plate discharging roller portions (plate discharging rollers 50a, 50b and 50c) to the original position (S5).

Next, the control means 115 as the ink state determining means determines whether or not the ink adhered to the master 23 to be peeled can be reused (S6). This determination is made in consideration of the idle time of the master 23 managed by the timer 118. The control unit 115 stores a temporal threshold (experimental data) for determining the deterioration of the ink, and the control unit 115 determines whether the ink can be reused based on the threshold. Depending on changes in environmental conditions such as temperature and humidity, the deterioration speed of the ink may be increased. Therefore, control for correcting the temporal threshold based on the detection data of the temperature sensor 119 and the humidity sensor 120 may be performed. If it is determined that the state of the ink is reusable, the squeegee solenoid 103 is used as shown in FIG.
Is turned on (S7), and the blade 54 is moved to the plate discharging roller 50b.
It contacts the upper master 23. Further, the ink collecting roller lifting motor 71 is driven to lower the ink collecting roller 53, and comes into contact with the plate discharging roller 50a and stops (S8).

The contact of the blade 54 with the master 23 backed up by the plate discharge roller 50 b
Since it is adjusted by the elastic force of the second spring 109, a substantially uniform pressure contact state is achieved over the entire roller axial direction. That is, uneven scraping of the ink of the blade 54 can be prevented.

Next, the plate discharging roller 50b is driven to rotate (S9). By this rotation, the ink adhering to the master 23 is scraped off by the blade 54 and transferred to the plate discharging roller 50a, and is collected in the ink pool 56 between the plate discharging roller 50a and the ink collecting roller 53. Next, the control means 115 checks whether or not the trailing end of the master 23 has been detected by the master detection sensor 55, that is, whether or not the discharging operation has been completed (S10). As shown in FIGS. 9 and 10, the squeegee solenoid 103 is turned off and the blade 54 is raised (S11). Further, the plate discharge roller driving motor 121 is driven to raise the plate discharge roller 50a, and the ink recovery roller lifting motor 71 is driven to raise the ink recovery roller 53 (S12).

Next, the lock solenoid 72 is turned on to mechanically fix the position of the plate discharging roller 50a (S13). However, the ink collection roller 53 can be moved up and down. In this state, the ink collecting roller lifting motor 71 is driven to slightly raise the ink collecting roller 53 (S14). By the slight movement of the ink collecting roller 53, the plate discharging roller 50
A gap g is formed between a and the ink collection roller 53. Next, the printing pressure solenoid 116 is turned on, and the ink collecting roller 53 contacts the plate cylinder 2 (S15). Next, the plate cylinder 2 is rotated (S16), and accordingly, the ink recovery roller 53 is also rotated. By the rotation of the ink recovery roller 53, the ink in the ink pool 56 is supplied to the outer peripheral surface of the plate cylinder 2 by a fixed amount via the gap g. That is, the plate discharging roller 50a functions as a doctor roller for making the thickness of the ink layer of the ink collecting roller 53 constant (claim 6).
Thereby, the ink return to the plate cylinder 2 can be made substantially uniform without unevenness.

Although not shown, the ink reservoir 56 is provided with an ink detection sensor for detecting ink, and the control means 115 checks the presence or absence of the recovered ink based on a detection signal from the ink detection sensor (S17). When the collected ink in the ink reservoir 56 runs out,
The printing pressure solenoid 116 is turned off to release the printing pressure (S1).
8) The plate discharge roller lifting motor 58 is driven to lower the plate discharge roller 50a (S19). In S6, if it is determined that the ink state cannot be reused, the plate discharging roller 50b is rotated without lowering the blade 54 to perform a normal plate discharging operation (S20).

For some reason, there is a possibility that the collected ink in the ink pool 56 is left as it is. In such a case, it is also possible to drive the ink collecting roller lifting motor 71 to slightly raise the ink collecting roller 53 to cause the remaining ink to adhere to the master 23 discharged in the normal plate discharging operation.

[0044]

According to the first aspect of the present invention, a plate discharging device is provided so as to be capable of coming into contact with and separating from the plate cylinder, and a plate discharging means for peeling a used stencil sheet from the plate cylinder; Since the ink scraping means for scraping the ink adhering to the stencil paper and the ink collecting means for returning the ink scraped by the ink scraping means to the plate cylinder,
By reusing ink, the ratio of the actual use amount to the ink supply amount can be increased, and waste of ink can be suppressed. Further, since the number of times of replacing the ink pack can be reduced, the labor involved in the replacement operation can be reduced.

According to the second aspect of the present invention, the ink scraping means comes into contact with the used stencil sheet and transfers the scraped ink to the plate discharging means, and the blade is moved between the contact position and the retreat position. In this configuration, a contact / separation mechanism for selectively positioning the plate is provided, so that a normal plate discharging operation can be arbitrarily performed.

According to the third aspect of the present invention, the contact pressure of the blade with respect to the stencil paper is variably provided through elastic force. It can be made substantially uniform over the entire removal area, and uneven scraping can be eliminated.

According to the fourth aspect of the present invention, since the ink collecting means has an ink collecting roller which can freely contact and separate from both the plate discharging means and the plate cylinder, the ink is returned to the plate cylinder. The operation can be performed efficiently.

According to the fifth aspect of the present invention, the plate discharging means has a pair of plate discharging rollers for separating used stencil paper from the plate cylinder, and one of these plate discharging rollers is the other plate discharging roller. The one plate discharge roller is provided so as to be movable with respect to the recording medium, and the one plate discharge roller constitutes an ink collecting means together with the ink collecting roller at the moved position, so that the ink returning operation to the plate cylinder can be performed efficiently.

According to the sixth aspect of the present invention, one of the plate discharging rollers forms an ink pool with the ink collecting roller at the moved position, and the amount of ink returned from the ink collecting roller to the plate cylinder. Is configured to function as a doctor roller for making the ink substantially uniform, so that it is possible to suppress the occurrence of unevenness in the return of ink to the plate cylinder and, consequently, the occurrence of shading in the next printing.

According to the seventh aspect of the present invention, since the locking means for fixing the position of one of the plate discharging rollers at the moved position is provided, the return amount of the ink can be made substantially uniform with high precision. Can be done.

According to the eighth aspect of the present invention, the ink collecting roller has a cam structure for avoiding interference with the projection of the plate cylinder between the ink collecting roller and the plate cylinder. In addition, it is possible to prevent unnecessary portions on the plate cylinder from being stained with the ink, such as adhesion of ink to a clamper or the like on the plate cylinder.

According to the ninth aspect of the present invention, there is provided an ink state judging means for judging the degree of deterioration of the ink adhering to the used stencil paper with time, and the ink state judging means makes it impossible to reuse the ink. If it is determined that the ink is not scraped and collected, the normal plate discharging operation is performed, so that the ink that cannot be reused mixes with the ink on the plate cylinder, and the overall deterioration of the ink during use Can be prevented.

According to the tenth aspect of the present invention, since there is provided a clocking means, and the ink state determining means determines the ink state based on the idle time measured by the clocking means, the configuration is simple. The state of the ink can be determined.

According to the eleventh aspect of the present invention, there is provided an environmental state detecting means for detecting an environmental state, and the ink state determining means determines the ink state based on the environmental state detected by the environmental state detecting means. With the configuration, the ink state can be determined with a simple configuration.

According to the twelfth aspect of the present invention, the ink adhering to the used stencil sheet peeled off from the plate cylinder is scraped off, and the collected ink is returned to the surface of the plate cylinder to perform the next printing. Since the ink is reused, the ratio of the actual use amount to the ink supply amount can be increased by reusing the ink, and the waste of the ink can be suppressed. Further, since the number of times of replacing the ink pack can be reduced, the labor involved in the replacement operation can be reduced.

According to the thirteenth aspect of the present invention, the state of the ink adhering to the used stencil sheet is determined, and if it is determined that the stencil sheet cannot be reused, the ink is not recovered and used as it is. Since the stencil sheet is discharged from the stencil sheet, it is possible to prevent overall deterioration of the in-use ink due to mixing of non-reusable ink with ink on the plate cylinder.

[Brief description of the drawings]

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

FIG. 2 is a schematic front view showing a relationship between a plate discharging unit and an ink collecting unit.

FIG. 3 is a schematic plan view showing locking means.

FIG. 4 is a schematic perspective view showing the relationship between the ink scraping means and the plate discharging means.

FIG. 5 is a control block diagram.

FIG. 6 is a flowchart illustrating a plate discharge control operation.

FIG. 7 is a front view of a main part showing an initial state in which the stencil sheet is peeled from the plate cylinder.

FIG. 8 is a front view of a main part showing a state of scraping by ink scraping means.

FIG. 9 is a main part front view showing a state in which the collected ink is returned to the plate cylinder.

FIG. 10 is a main part front view showing a state in which collected ink is returned to a plate cylinder.

[Explanation of symbols]

 2 plate cylinder 23 master as stencil sheet 48 plate discharge device 50a, 50b, 50c plate discharge roller 50a, 50b as plate discharge means plate discharge roller 50a as a pair of plate discharge roller 50a one plate discharge roller 50b the other plate discharge roller 51 ink scraping means 53 Ink recovery roller 54 Blade 56 Ink pool 95 Locking means 102 Contacting / separating mechanism 115 Control means as ink state determining means 118 Timer as time keeping means 119 Temperature sensor as environmental state detecting means 120 Humidity sensor as environmental state detecting means

Claims (13)

[Claims] 1. A stencil printing apparatus having a stencil printing device for removing used stencil paper from a plate cylinder and storing the stencil sheet, wherein the stencil printing device is provided so as to be able to approach and separate from the plate cylinder. Plate discharging means for peeling used stencil paper, ink scraping means for scraping ink adhering to the used stencil paper, and returning the ink scraped by the ink scraping means to the plate cylinder. A stencil printing machine having ink collecting means. 2. A stencil printing machine according to claim 1, wherein said ink scraping means comes into contact with said used stencil sheet and transfers the scraped ink to said stencil discharging means; A stencil printing machine having a contact / separation mechanism for selectively positioning a position and a retreat position. 3. A stencil printing apparatus according to claim 2, wherein a contact pressure of said blade against said stencil sheet is variably provided through elastic force. 4. A stencil printing machine according to claim 1, wherein said ink collecting means has an ink collecting roller which can freely contact and separate from both said plate discharging means and said plate cylinder. Printing device. 5. The stencil printing apparatus according to claim 4, wherein said plate discharging means has a pair of plate discharging rollers for separating said used stencil sheet from said plate cylinder, and one of said plate discharging rollers. A stencil printing apparatus characterized in that the stencil printing device is provided movably with respect to the other stencil discharging roller, and the one stencil discharging roller constitutes the ink collecting means together with the ink collecting roller at the moved position. 6. A stencil printing apparatus according to claim 5, wherein said one plate discharging roller forms an ink reservoir between said ink collecting roller at a position where said plate discharging roller is moved, and said one plate discharging roller transfers said ink from said ink collecting roller to said plate cylinder. A stencil printing apparatus which functions as a doctor roller for making the amount of ink returned substantially uniform. 7. A stencil printing apparatus according to claim 6, further comprising a lock means for fixing the position of said one stencil discharge roller at said moved position. 8. The stencil printing machine according to claim 4, wherein said ink collecting roller is arranged to avoid interference with a convex portion of said plate cylinder between said ink collecting roller and said plate cylinder. A stencil printing apparatus characterized by having the above cam configuration. 9. The stencil printing apparatus according to claim 1, further comprising an ink state judging means for judging a degree of deterioration of the ink adhering to the used stencil sheet with time. A stencil printing apparatus characterized in that when the ink state judging means judges that the ink cannot be reused, a normal plate discharging operation is performed without scraping and collecting ink. 10. A stencil printing machine according to claim 9, further comprising a time measuring means, wherein said ink state judging means judges the ink state based on the idle time measured by said time measuring means. Printing device. 11. The stencil printing apparatus according to claim 9, further comprising an environmental state detecting means for detecting an environmental state, wherein said ink state determining means is configured to detect an ink state based on the environmental state detected by said environmental state detecting means. A stencil printing apparatus characterized by determining the following. 12. A stencil sheet made of stencil is wound around the outer peripheral surface of a plate cylinder, ink is supplied from the inside of the plate cylinder, and printing paper is pressed against the outer peripheral surface of the plate cylinder to form an ink from the stencil sheet. In the printing method of performing printing by exuding the stencil, the ink adhering from the used stencil paper peeled off from the plate cylinder is scraped, and the collected ink is returned to the surface of the plate cylinder to perform the next printing. A printing method characterized by being reused. 13. The printing method according to claim 12, wherein the state of the ink adhering to the used stencil sheet is determined, and if it is determined that the stencil sheet cannot be reused, the ink is not collected and is not collected. A printing method characterized by discharging a used stencil sheet.