JP2000313158A - Stencil printing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make economical use of a long-size stencil base paper, even when a user erroneously sets or sets due to necessity a printing paper of a larger size than a copy on a paper feed table. SOLUTION: This stencil printing device comprises an original reading part 1 for reading a copy, a plate-making part 2 which thermally perforates a long-size stencil base paper 16 using a thermal head 18 based on image information to be read by the original reading part 1 and cuts the long-size stencil base paper 16 to make a plate-making base paper and a printing part 3 which winds the plate-making base paper prepared by the plate-making part 2 around a plate cylinder 25 and presses a printing paper 34 to the plate cylinder 25 with the help of a paper pressing means 36. In addition, the device is equipped with a copy size detecting means, which detects the size of the copy for making the stencil base paper 16 by the thermal head 18 and a pressing period adjusting means which adjusts a period when the paper pressing means 36 presses the printing paper 34 to the plate-making base paper in compliance with the size of the copy detected by the copy size detecting means after the plate- making part 2 prepares the plate-making base paper in accordance with the size of the copy by cutting the long-size stencil base paper 16 according to the size of the copy detected by the copy size detecting means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stencil printing machine for making a stencil sheet by forming a stencil sheet and printing on a printing sheet based on the stencil sheet.

[0002]

2. Description of the Related Art A stencil printing apparatus includes a document reading unit for reading a document as an electric signal, and a thermal head for perforating a long stencil sheet based on image information read by the document reading unit with a thermal head. A stencil making section for cutting a stencil stencil sheet at a predetermined position to make a stencil sheet, and a stencil sheet made by the stencil section are wound around a plate cylinder, and the printing paper is transported in synchronization with the rotation of the plate cylinder, and A printing unit that presses the printing paper against the stencil sheet of the plate cylinder during this conveying process to transfer the ink from the stencil portion of the stencil sheet to the printing paper.
In the related art, the cutting length of the long stencil sheet is always constant, that is, for example, set to the maximum size of the printing paper. However, when the printing paper having a small size is used, the long stencil sheet is wasted. Met.

In order to solve this problem, the size of the printing paper set in the paper feeding section is detected, and the cutting length of the long printing stencil is adjusted in accordance with the size of the printing paper to thereby obtain the long printing stencil. Has been proposed (see Patent Publication No. 2625437).

[0004]

However, in the conventional stencil printing apparatus, the printing paper that is larger than the original is printed because the user erroneously or the user needs it (when the user wants to print on a printing paper larger than the original size). When set on a paper feed table, there is a problem that long stencil paper cannot be saved.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and is intended to be applied to a case where a user erroneously sets a printing sheet larger than a document on a sheet feeder because the user needs it. An object of the present invention is to provide a stencil printing apparatus that saves stencil printing paper.

[0006]

According to a first aspect of the present invention, there is provided a document reading section for reading a document as an electric signal, and thermal piercing of a long stencil sheet with a thermal head based on image information read by the document reading section. A stencil making section for cutting the heat-perforated long stencil sheet at a predetermined position to form a stencil sheet;
The plate making unit has a stencil made by the stencil wrapping around the plate cylinder, and has sheet pressing means for pressing the printing paper conveyed in synchronization with the rotation of the plate cylinder. In a stencil printing apparatus that performs stencil printing by transferring ink from a perforated portion of a wrapped stencil sheet to printing paper, a stencil printing apparatus is provided with a manuscript size detecting means for detecting a manuscript size. Accordingly, the long stencil sheet is cut to prepare a stencil sheet according to the size of the original.

In this stencil printing apparatus, when a document is set on the document reading section, the document size detecting means detects the size of the document, and the long stencil sheet is cut in accordance with the document size to produce a stencil sheet. Can be

According to a second aspect of the present invention, there is provided the stencil printing apparatus according to the first aspect, wherein the paper pressing means adjusts a period during which the paper pressing means presses the printing paper in accordance with the document size detected by the document size detecting means. A period adjusting means is provided.

In this stencil printing apparatus, in addition to the operation of the first aspect, the pressing period adjusting means adjusts the pressing period of the sheet pressing means according to the size of the stencil sheet, and the sheet pressing means is wrapped around the stencil sheet. Do not press against the plate cylinder in the non-position.

[0010] The invention of claim 3 is claim 1 or claim 2.
The stencil printing apparatus according to claim 1, wherein the original size detecting unit detects an original original size read by the original reading unit, and detects a changed original size that is changed by selecting a scaling mode. Means.

In the stencil printing apparatus, in addition to the effect of the first or second aspect, when the magnification mode is selected and the print size is changed with respect to the original size, the changed original size is detected. Then, the elongate stencil sheet is cut in accordance with the changed original size to produce a stencil sheet.

[0012]

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

1 to 11 show an embodiment of the present invention.
FIG. 1 is a schematic configuration diagram of a digital stencil printing apparatus.

In FIG. 1, the digital stencil printing apparatus mainly comprises a document reading section 1, a plate making section 2, a printing section 3, a paper feeding section 4, a paper discharging section 5, and a plate discharging section 6.

The document reading section 1 has an automatic document feed reading section 7 and a document placing reading section 8. The automatic document feed reading unit 7
An obliquely inclined original plate 9 on which an original is placed, and a pair of fences 1 for regulating both sides of the original placed on the original inclined plate 9
0 (shown in FIG. 2), a document transport unit (not shown) for transporting a document placed on the document inclined plate 9, a line image sensor 11 for converting the content of the transported document into an electric signal and reading the signal. It is composed of The line image sensor 11 is also used as the one of the original placing / reading unit 8.

The original placing and reading section 8 includes a horizontal original placing glass table 12 on which an original is placed, and an original placing glass table 12.
A pressure plate 13 that can be opened and closed above, a guide belt 15 that is disposed below the original placing glass table 12 and that is moved by the driving force of a read pulse motor 14, and that the original placing glass is guided by the guide belt 15. A line image sensor 11 that moves below the table 12;

The document of the automatic document feeder 7 is
The line image sensor 11 is located at the right end in FIG. 1, and the line image sensor 11 reads a document transported by a document transport unit (not shown). The original of the original placing and reading section 8 moves with the line image sensor 11 being guided by the guide belt 15, and reads the contents of the original.

The stencil making section 2 includes a stencil containing section 17 for accommodating a rolled long stencil 16 and a stencil containing section 17.
A thermal head 18 disposed downstream of the long stencil sheet 16 in the transport direction, a platen roller 20 disposed at a position facing the thermal head 18 and rotated by a driving force of a write pulse motor 19, and a platen roller 20. 2
0 and the thermal head 18, a pair of stencil feed rollers 21, a pair of stencil feed rollers 21, and the platen roller, which are disposed downstream of the elongate stencil sheet 16 in the transport direction with respect to the thermal head 18 and are rotated by the driving force of the write pulse motor 19. 20 and the thermal head 18, the cutter driving unit 2
2 (shown in FIG. 9). The thermal head 18 has a plurality of point-like heating elements arranged in a direction perpendicular to the transport direction of the long stencil sheet 16, and in this embodiment, since the maximum printing paper is A3, the thermal printing is performed over a range of A3 width. A heating element is arranged.

The long stencil sheet 16 is conveyed by the rotation of the platen roller 20 and the stencil feed roller 21, and each point heating element of the thermal head 18 is selectively selected based on image information read by the line image sensor 11. The heat-generating operation perforates heat-perforated elongate stencil paper 16 by heat, and cuts a predetermined portion of the heat-perforated elongate stencil paper 16 with a base paper cutter 23 to produce a stencil sheet. This cutting position will be described in detail below.

The printing unit 3 has an outer peripheral portion made of an ink-permeable member having a porous structure. The printing cylinder 3 rotates in the direction indicated by the arrow A in FIG. A clamp unit 26 provided on the surface of the plate cylinder for clamping the leading edge of the plate making paper; a document confirmation sensor (not shown) for detecting whether or not the plate making paper is attached to the outer periphery of the plate cylinder 25; Reference position sensor 28 for detecting the reference position of plate cylinder 25 by detecting piece 27
And a rotary encoder 29 for detecting rotation of the main motor 24. The rotational position of the plate cylinder 25 can be detected by detecting the output pulse of the rotary encoder 29 based on the detection output of the reference position sensor 28.

The printing unit 3 includes a squeegee roller 30 and a doctor roller 31 disposed inside the plate cylinder 25.
And an ink bottle 33 for accommodating a stencil emulsion ink 32, which is an ink to be supplied between the rollers 30 and 31, and a printing paper 34 conveyed in synchronization with the rotation of the plate cylinder 25. And a sheet pressing means 36 for pressing the 25 stencil sheets with a press roller 35. The detailed configuration of the sheet pressing means 36 will be described in detail below.

The leading edge of the stencil sheet conveyed from the stencil making section 2 is clamped by a clamp section 26. In this clamped state, the plate cylinder 25 is rotated, and the stencil sheet is wound around the outer circumference of the plate cylinder 25 and mounted. When the printing paper 34 conveyed in synchronization with the rotation of the printing drum 25 is pressed against the stencil sheet of the printing drum 25 by the paper pressing means 36, the ink is transferred from the stencil portion of the printing stencil to the printing paper 34 and the image is formed. Is printed.

The paper supply unit 4 includes a paper supply table 37 on which print papers 34 are stacked, and a print paper 3 at an uppermost position from the paper supply table 37.
4, a pair of timing rollers 39 for transporting the printing paper 34 moved by the paper supply roller 38 between the plate cylinder 25 and the press roller 35 in synchronization with the rotation of the plate cylinder 25. And a paper sensor 40 for detecting whether or not the printing paper 34 has been transported between the pair of timing rollers 39. The rotation of the main motor 24 is selectively transmitted to the paper feed roller 38 via a paper feed clutch 41.

The paper discharge unit 5 is a printing paper 34 on which printing has been completed.
From the plate cylinder 25, a belt conveyor transport mechanism 43 that transports the printing paper 34 that has been peeled off by the paper peel nails 42, and printing that has been transported by the belt conveyor transport mechanism 43. And a stacker section 44 on which the used printing papers 34 are placed in a stacked state.

The plate discharge section 6 is provided with a plate discharge separation claw 45 for peeling the plate-making stencil wound around the plate cylinder 25 from the plate cylinder 25.
And a pair of plate discharging rollers 46 for transporting the plate making paper peeled off by the plate discharging separating claws 45, and a plate discharging box 47 for storing the plate making paper conveyed by the pair of plate discharging rollers 46.

FIG. 2 is a plan view of the automatic document feeder / reader 7 of the document reader 1. In FIG. 2, a pair of fences 1 for restricting both sides of a document placed on a document inclined plate 9 are shown.
0 is provided, and the pair of fences 10 is configured to be movable in a direction in which the distance between the fences 10 can be varied. And
The automatic document feeder 7 is provided with a potentiometer 50 for detecting the width of the document by detecting the movement position of the pair of fences 10, and a document length / width detection sensor 51 for detecting whether the document is placed vertically or horizontally. ing. The detection data of the potentiometer 50 and the document vertical / horizontal detection sensor 51 are supplied to a control unit 52 (shown in FIG. 9), and the size of the original document is detected based on these data as described below.

FIG. 3 is a plan view of the original placing and reading section 8 of the original reading section 1. In FIG. 3, the original placing glass table 1
2, two document width detection sensors 53 for detecting the size of the document in the width direction and a document length and width detection sensor 54 for detecting whether the document is placed vertically or horizontally. The detection data of the five document width detection sensors 53 and the document length / width detection sensor 54 are supplied to a control unit 52 (shown in FIG. 9), and the original document size is detected based on these data as described below. .

FIGS. 4 to 6 are structural views showing the structure of the plate cylinder and the paper pressing means 36, respectively. 4 to 6, the paper pressing means 36 includes a first lever 6 rotatably supported by a device main body (not shown) about a support shaft 60.
1 and a second lever 62 fixed to the first lever 61 and rotatably supported about a support shaft 60. The press roller 35 described above is rotatable at the tip of the second lever 62. It is supported by. Press roller 3
5 is moved between a pressing position for pressing the plate cylinder 25 by the rotation of the first and second levers 61 and 62 and a separating position for separating from the plate cylinder 25. One end of a biasing spring 63 is hung on the first lever 61 and is biased toward the pressing position by the spring force of the biasing spring 63. Also, the first lever 6
Reference numeral 1 has a first branch arm 61a and a second branch arm 61b, and a main cam 64 can be engaged with the first branch arm 61a, and a sub cam 65 can be engaged with the second branch arm 61b.

The main cam 64 is composed of a small-diameter cam surface 64a having a small distance from the center of rotation, a large-diameter cam surface 64b having a large distance from the center of rotation, and an inclined cam surface 64c connecting the two. It is rotated by a driving force of 66. As shown in FIG. 5, at the pressing allowable position where the small diameter cam surface 64 a is engaged with the first lever 61, the press roller 35 is located at the pressing position by the spring force of the urging spring 63, and as shown in FIG. Large diameter cam surface 64
At the pressure release position where b is engaged with the first lever 64, the press roller 35 is located at a large separation position where the press roller 35 is largely separated against the spring force of the biasing spring 63. Then, the main cam drive motor 66 is driven in synchronization with the rotation of the plate cylinder 25, and the press roller 35 is in the pressing position in the rotation position where the stencil sheet of the maximum print size A3 is wrapped, and in the other rotation positions. The press roller 35 is located at a large separation position. By locating the press roller 35 at the large separation position, the press roller 35 escapes from the clamp 26 or the like.

The sub-cam 65 is composed of a small-diameter cam surface 65a whose distance from the rotation center is small, an inclined cam surface 65b whose distance from the rotation center gradually increases, and a vertical cam surface 65c connecting these. Drive motor 6
7 is rotated by the driving force. At the pressing allowable position where the small diameter cam surface 65a engages with the first lever 61 as shown in FIG. 5, the press roller 35 is located at the pressing position by the spring force of the biasing spring 63, and as shown in FIG. Cam surface 6
At the pressure release position where 5 b is engaged with the first lever 61, the press roller 35 is located at the small separation position where the press roller 35 is separated slightly against the spring force of the biasing spring 63. The drive of the sub-cam drive motor 67 is controlled by the control unit 52, and the control unit 52 adjusts the period during which the press roller 35 presses the printing paper 34 against the stencil sheet of the plate cylinder 25 according to the document size. That is, the control unit 52, the sub-cam driving motor 67, and the sub-cam 65 constitute the pressing period adjusting unit A1.

The printing start point and the printing end point in FIGS. 5 and 6 show the case of A3 size which is the maximum original size.

FIG. 7 is a front view of the operation panel 70, and FIG. 8 is an enlarged front view of a main part of the operation panel 70. 7 and 8, the stencil printing apparatus is provided with an operation panel 70 for a user to input a predetermined command and the like. The operation panel 70 includes a stencil making start key 71, a stop key 72, a print number, and the like. There are provided a numeric keypad 73 for inputting, and respective scaling keys 74a to 74d for enlargement / reduction. The input signals of the various keys are output to the control unit 52. As shown in FIG. 8, the types of the scaling keys 74a to 74d in this embodiment include a reduction key 74a, an equal-size key 74b, and an
4c, a zoom key 74d, and the like. The operation panel 70
Is provided with a liquid crystal display section 75 for displaying a warning or the like in response to a display command from the control section 52.

FIG. 9 is a circuit block diagram of the stencil printing apparatus. In FIG. 9, the control unit 52 is configured to be able to read data from a ROM 76,
An execution program for the print mode and the like is stored. Corresponding table data of the document size and the base sheet cutting count value and the press release count value of the rotary encoder 29, that is, the long stencil sheet 16 corresponding to the length of each document size. The number of pulses to the main motor 24 necessary to move the motor is stored. The control unit 52 has a built-in encoder counter (not shown) and is configured to be able to count the number of output pulses of the rotary encoder 29. The control unit 52 is configured to be able to read and write data in the RAM 77.

The control unit 52 executes a desired operation based on the information input from the operation panel 70, such as a document reading unit 1, a plate making unit 2, a printing unit 3, a paper feeding unit 4, a paper discharging unit 5, and a plate discharging unit 6. Are controlled. The contents of this control will be described in the following description of the operation.

The control unit 52 includes an automatic document feed / read unit 7
A potentiometer 50 and a document vertical / horizontal detection sensor 51,
Alternatively, five original width detection sensors 53 of the original placing / reading section 8
Means for detecting the original document size read by the document reading unit 1 from the data from the document vertical / horizontal detection sensor 54, and a variable original document size which is changed by selecting a magnification based on the original document size data Means for detecting That is, the potentiometer 50 and the document length / width detection sensor 51 of the automatic document feed / read unit 7 and the document placement / reading unit 8
The five document width detecting sensors 53 and the document vertical / horizontal detecting sensors 54 and the control unit 52 constitute a document size detecting means A2. The cutting position of the long stencil sheet 16 is adjusted according to the document size detected by the document size detection means A2, and the period during which the paper pressing means 36 presses the printing paper 34 against the plate cylinder 25 is adjusted. You. The details of this adjustment will be described later in the description of the operation.

Next, the operation of the stencil printing apparatus will be described with reference to the flow charts of FIGS. In FIG.
The original is read by the automatic original feed reading unit 7 of the original reading unit 1 or
The plate making start key 71 is set on the
Is pressed (step S1), the contents of the original are read by the line image sensor 11 of the original reading unit 1 and
A potentiometer 50 and a document length / width detection sensor 51,
Alternatively, the outputs of the five original width detecting sensors 53 and the original vertical / horizontal detecting sensors 54 are fetched and the variable magnification keys 74a to 74
The input state of d is taken in to detect the document size (step S2). Then, a base paper cutting count value and a press release count value based on the detected document size are read from the ROM 76 (step S3).

Next, the main motor 24 is driven to drive the plate cylinder 2.
5 is rotated (step S4), and the plate discharging process is executed based on the timing at which the output of the reference position sensor 28 is turned on (steps S5 and S6). That is, the unnecessary plate making paper is peeled off from the plate cylinder 25 by the plate discharging separation claw 45 and sent to the plate discharging box 47 by the pair of plate discharging rollers 46. If the plate discharging process is defective, an error is displayed (steps S7 and S8). When the stencil discharge is completed successfully, the light pulse motor 19 is driven to drive the platen roller 20 and the stencil feed roller 21 by a fixed amount, and the leading end of the long stencil sheet 16 is clamped by the clamp unit 26 (steps S9 and S10). ) And line image sensor 1
Based on the image information read in step 1, the thermal head 18 is operated to generate heat to perform a stencil making process for forming a stencil on the long stencil 16 (step S11). The plate making process is performed according to the size of the original by the scaling setting of the scaling keys 74a to 74d.

Next, the main cylinder 24 is driven to drive the plate cylinder 2.
5 (step S12), and the reference position sensor 28
Is turned on (step S13), the encoder counter is reset, and counting of the output pulse of the rotary encoder 29 is started (step S14). Then, the output of a base paper confirmation sensor (not shown) is checked (step S15). When the reference position sensor 28 is turned on without the output of the stencil confirmation sensor (not shown) being turned on, it is determined that the stencil making paper has not been normally wound around the outer peripheral surface of the plate cylinder 25 and the main motor 24 is driven. Is stopped and an error is displayed (steps S16, S17, S1).
8).

When the output of a base paper confirmation sensor (not shown) is turned on and the paper feed start rotation position is reached, the paper feed clutch 41
Are connected (steps S19 and S20). Then, the paper feed roller 38 of the paper feed unit 4 is driven to drive the uppermost print paper 34.
Is moved. When the leading end of the printing paper 34 is transported to the position of the pair of timing rollers 39, the paper sensor 40 is turned on (step S21). When the paper sensor 40 is turned on, the paper feed clutch 41 is disengaged, and the main cam drive motor 66 is driven (step S22). When the count value of the encoder counter matches the base paper cutting count value (step S23), the cutter driving unit 2
2 is driven and the long stencil sheet 16 is cut by the stencil cutter 23, thereby making a stencil sheet (step S24). More specifically, the stencil sheet has a length corresponding to the size of the original, and is wound around the outer peripheral surface of the plate cylinder 25 with its leading end clamped by the clamp unit 26.

Further, a pair of timing rollers 39 rotate in synchronization with the rotation of the plate cylinder 25, and the printing paper 34 is supplied in synchronization with the rotation position of the plate cylinder 25. 1 is pressed by the plate making
The test print is performed (step S25).

Next, when the reference position sensor 28 is turned on (step S26), the encoder counter is reset and the counting of output pulses of the rotary encoder 29 is started (step S27). Then, the printing paper 34 at the uppermost portion of the paper feeding unit 4 described above is conveyed one by one to the position of the pair of timing rollers 39 (step S2).
8). If the press release count value is not smaller than the maximum value (step 29), that is, if the document size is A3, the sub-cam drive motor 67 is not driven. That is, the printing paper 34 is supplied in synchronization with the rotation of the plate cylinder 25, and the main cam driving motor 66 is driven. And A
At the rotation position where the three sizes of the plate making document are wound, the press roller 35 presses the printing paper 34 against the plate making paper of the plate cylinder 25 for printing, and at the other rotation positions, the press roller 35 is actuated by the main cam 64 to operate the plate cylinder. Separated from 25. The printed printing paper 34 is discharged by the discharge unit 5 (step S34). That is, the printed printing paper 34 is peeled off from the plate cylinder 25 by the paper peeling claw 42, and the stacker 44 is moved by the belt conveyor transport mechanism 43.
It is placed on the stack.

If the press release count value is smaller than the maximum value (step S29), that is, if the document size is smaller than A3, it is checked whether the encoder count value matches the press release count value (step S29). S
30), at the time of coincidence, the sub-cam drive motor 67 is driven to move the press roller 35 to the small separation position in FIG. 6 (step S31). Then, when the reference position sensor 28 is turned on, that is, when the plate cylinder 25 makes one rotation and returns to the original reference position (step S32), the sub-cam drive motor 67 is driven to return to the pressing allowable position in FIG. 4 (step S32). S3
3). However, even if the sub-cam drive motor 67 is returned to the press-permissible position in FIG. 4, the press roller 35 is positioned at a large separation position by the main cam 64 at a rotational position near the reference position of the plate cylinder 25. The roller 35 is not located at the pressing position. Further, the printed printing paper 34 is subjected to a paper discharging process by the paper discharging unit 5 as described above (step S34).

Then, each time one printing is completed, it is checked whether the number of prints matches the designated number (step S35). If not, the above printing process is repeated.
If the number matches the specified number, the drive of the main cam drive motor 66 and the main motor 24 is stopped (step S36),
This completes.

In the plate making operation, when a document is placed on the automatic document feeder / reader 7 of the document reader 1, or the document placement / reading unit 8, the document size is detected by the document size detector A2. Is done. Then, the elongate stencil sheet 16 is cut in accordance with the original size detected by the original size detecting means A2, thereby producing a stencil sheet. For example, if the original size is B5 in the vertical direction, a stencil sheet having a B5 size vertical length is produced. Therefore, the long stencil sheet 16 can be saved even when the user erroneously sets the printing paper 34 larger than the original document on the paper feed table 37 because the user needs it.

In this embodiment, the original size detecting means A2 detects the variable original size when the print size is changed with respect to the original original size by selecting the magnification mode, and the changed original size is detected. Since the perforated stencil 16 is cut according to the size of the original to form the stencil, the user mistakenly sets the printing paper 34 larger than the original on the paper feed table 37 in the magnification mode or because the user needs it. Also in this case, the long stencil sheet 16 can be saved.

During the printing operation, the pressing period of the press roller 35 is adjusted according to the document size detected by the document size detecting means A2. In other words, if the original size is A3 size, the press roller 35 presses the stencil sheet at the rotational position where the stencil sheet is wound as shown in FIG. Rotates to the pressing release position, and the press roller 35 is positioned at the large separation position as shown in FIG. If the document size is a small size other than A3, the sub-cam 65 is not limited to the position where the stencil sheet is wrapped by the pressing period adjusting means A1 of the paper pressing means 36, as well as to the clamping section 26 and its surrounding opposing position. Rotates to the pressing release position, and the press roller 35 is positioned at the small separation position as shown in FIG. Therefore, the press roller 35 does not press the plate cylinder 25 at a position where the stencil sheet is not wound, so that the emulsion ink 32 on the plate cylinder 25 side does not adhere to the press roller 35.

According to the above-described embodiment, the pressing period adjusting means A1 of the paper pressing means 36 releases the pressing of the press roller 35 at the position where the stencil sheet is not wound by using the sub-cam 65. However, any configuration may be used as long as the pressing of the press roller 35 can be released at a position where the stencil sheet is not wound.
It is also possible to change the rotation speed with respect to the rotation position according to the document size.

Further, the paper pressing means 36 is
5 is fixed, the squeegee roller 30 inside the plate cylinder 25 presses the peripheral wall of the plate cylinder 25 outward, and the printing paper 34 is sandwiched between the press roller 35 and the stencil sheet of the deformed portion of the plate cylinder 25. In the stencil printing apparatus of the so-called middle-pressing type, the pressing of the squeegee roller 30 can be similarly released, and the release can be changed according to the document size.

According to the above-described embodiment, the original reading section 1 has the automatic original feeding / reading section 7 and the original placing / reading section 8, and the original size detecting means A2 determines which one of the originals is placed. In the present invention, the original reading unit 1 has only one of the automatic original feed reading unit 7 and the original placing / reading unit 8 or the variable magnification keys 74a to 74
Needless to say, the present invention can be applied to a case without 4d.

[0050]

As described above, according to the first aspect of the present invention, the elongate stencil sheet is thermally perforated on the basis of the image information read by the original reading section and the elongate stencil sheet. A stencil making section by cutting the stencil sheet to form a stencil sheet, and a sheet pressing means for winding the stencil sheet made by the stencil sheet around the plate cylinder and pressing the printing paper; In a stencil printing apparatus provided with a printing unit for transferring ink from a perforated portion of a stencil sheet to printing paper, a document size detecting unit for detecting a size of a document to be formed by a head is provided. Since the long stencil sheet was cut in accordance with the detected original size to produce a stencil sheet in accordance with the original size, when the original is set in the original reading section, the original size detecting means is set to the original size. Detects, since the plate-making sheet is made elongated stencil sheet is cut according to the document size,
The long stencil sheet can be saved even when the user sets a printing sheet larger than the original sheet on the sheet feeder tray by mistake or because the user needs it.

According to the second aspect of the present invention, in the stencil printing apparatus according to the first aspect, the period in which the paper pressing means presses the printing paper is adjusted according to the document size detected by the document size detecting means. Since the pressing period adjusting unit is provided, in addition to the effect of the invention of claim 1, the pressing period adjusting unit adjusts the pressing period of the sheet pressing unit according to the size of the stencil sheet,
Since the printing paper is not pressed against the plate cylinder at a position where the paper pressing means is not wound around the plate making paper, ink on the plate cylinder side does not adhere to the paper pressing means.

According to a third aspect of the present invention, in the stencil printing apparatus according to the first or second aspect, the original size detecting unit detects an original original size read by the original reading unit. And means for detecting the original size after the change, which is changed by the selection of the scaling mode.
In addition to the effects of the first or second aspect of the present invention, when the scaling mode is selected and the print size is changed with respect to the original document size, the changed document size is detected, and the changed document size is detected. Since the long stencil sheet is cut to make the stencil sheet, the user can make mistakes in the magnification mode, or even if the user sets a printing paper larger than the original because the user needs it, the long stencil sheet is used. Stencil paper can be saved.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention, and is a schematic configuration diagram of a digital stencil printing apparatus.

FIG. 2 shows an embodiment of the present invention, and is a plan configuration diagram of an automatic document feeder / reader of the document reader.

FIG. 3 shows one embodiment of the present invention, and is a plan configuration diagram of a document placing and reading unit of the document reading unit.

FIG. 4 shows an embodiment of the present invention, and is a configuration diagram of a plate cylinder portion and a sheet pressing unit when a main cam is operated.

FIG. 5 is a configuration diagram illustrating an embodiment of the present invention, in which a printing drum and a paper pressing unit are printed.

FIG. 6 shows the embodiment of the present invention, and is a configuration diagram of the plate cylinder portion and the sheet pressing means when the sub-cam is operated.

FIG. 7 is a front view of the operation panel according to the embodiment of the present invention.

FIG. 8 shows an embodiment of the present invention and is an enlarged front view of a main part of an operation panel.

FIG. 9 shows an embodiment of the present invention and is a circuit block diagram of a stencil printing apparatus.

FIG. 10 shows an embodiment of the present invention, and is an operation flowchart of the first half.

FIG. 11 is a second half operation flowchart showing the embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 original reading section 2 plate making section 3 printing section 6 long stencil sheet 8 thermal head 25 plate cylinder 34 printing paper 36 paper pressing means A1 pressing period adjusting means A2 document size detecting means

Claims (3)

[Claims] 1. An original reading section for reading an original as an electric signal, and a thermal head perforating a long stencil sheet with a thermal head based on image information read by the original reading section. A plate making section for cutting a plate at a predetermined position to form a plate making paper, and a sheet pressing means for winding the plate making paper made by the plate making section around the plate cylinder and pressing the printing paper conveyed in synchronization with the rotation of the plate cylinder. A stencil printing apparatus for stencil printing by transferring ink from a perforated portion of a stencil stencil wound on the plate cylinder to printing paper by pressing by the sheet pressing means; Means for cutting the long stencil sheet according to the size of the document detected by the document size detection means to produce a stencil sheet corresponding to the size of the document. Printing device. 2. The stencil printing apparatus according to claim 1, further comprising a pressing period adjusting unit that adjusts a period during which the paper pressing unit presses the printing paper in accordance with the document size detected by the document size detecting unit. A stencil printing apparatus, characterized in that: 3. The stencil printing apparatus according to claim 1, wherein the original size detecting unit detects an original original size read by the original reading unit, and selects a magnification mode. Stencil printing apparatus, comprising means for detecting the size of the original after the change, which is made variable by the above.