JPS61287745A - Plate making device for stencil printing - Google Patents

Abstract

PURPOSE:To completely prevent the occurrence of thermal damage to thermal head and anomous plate making by a method in which an indication for detecting the feeding position of a paper for stencil printing is read out to judge the normality or anomaly of the feeding, and the plating making operation is stopped in the case of anomaly. CONSTITUTION:In a plate making device 17 between a paper storage container and a cylindrical plate 1, the plate of paper S for process printing is made thermally. From an indication reading device 40 provided to the device 17, electrical signals are sent out each time indications M for detecting the feeding position of the paper S are passed. In case where the feeding becomes anomalous by hot-bonding of the paper S to the thermal head 18, the interval of reading time for the indications M elongated to stop the output of image information signals through a controller to the thermal head 18. The heating action of the head 18 is practically stopped, plate making under defective conditions is stopped, and thermal damage to the heating elements can thus be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a stencil-making device for stencil printing, and particularly to a stencil-making device for stencil printing that performs stencil-making while feeding stencil printing paper in one direction.

Conventional Technology As one of the stencil printing apparatuses for making stencil sheets for stencil printing, a thermal head is used to perform thermal stencil making in a dot matrix manner while feeding the stencil printing sheet in one direction, that is, in the sub-scanning direction. A plate-making device for stencil printing has already been proposed, and this is disclosed in, for example, Japanese Patent Application Laid-Open No. 59-1436.
It is shown in Publication No. 79.

Problems to be Solved by the Invention The feeding of the stencil printing paper in the plate making process is performed by a friction method using a feeding roller device such as a platen roller, but for some reason an abnormality occurs in the feeding of the stencil printing paper.
If there is a stagnation in the feeding of the stencil printing paper, not only will normal stencil making not be performed, but the thermal head will repeatedly heat the same part of the stencil printing paper, causing the stencil printing paper in that area to become stagnant. The temperature rises abnormally, and the heat from the thermal head is no longer properly dissipated, which causes the thermal head to be in an abnormally high temperature state, and there is a risk that the heating element of the thermal head may burn out.

A thermal head is generally equipped with multiple heating elements, but if even one heating element is damaged and becomes inoperable, normal plate making will no longer be possible. The entire head will need to be replaced.

In thermal plate making using a thermal head, unlike thermal printing using a thermal head, plate making is performed by applying heat to the thermosensitive perforated synthetic resin film of the stencil printing base paper and locally burning it out. Therefore, the melted synthetic resin film is likely to be welded to the thermal head, and there is a high possibility that the feeding of the stencil printing base paper will be stopped due to this welding.

For this reason, in stencil printing equipment that performs thermal plate making using a thermal head, it is necessary to pay particular attention to whether or not the stencil printing base paper is being fed normally during the plate making process. .

SUMMARY OF THE INVENTION An object of the present invention is to provide an improved stencil printing apparatus that solves the above-mentioned problems.

Means for Solving the Problems According to the present invention, the above-mentioned object is to provide a stencil-making device for stencil printing which performs stencil-making while feeding a stencil paper in one direction, which comprises: an index reading device for reading a feeding position detection index, and a determination as to whether or not the stencil printing paper is being fed normally based on the index for detecting the feeding position of the stencil printing paper read by the index reading device; This is achieved by a stencil-making device for stencil printing, characterized in that it has an abnormality detection control means for stopping the stencil-making operation when the feeding of the stencil printing base paper is not normal.

Effects and Effects of the Invention According to the above-described configuration, the feeding state of the stencil printing paper,
In other words, the feed speed of the stencil printing paper is monitored sequentially,
If an abnormality occurs in the feeding of the stencil printing base paper, the subsequent plate-making operation is stopped, thereby preventing abnormal plate-making and also preventing thermal damage to the thermal head. Ru.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail by way of embodiments with reference to the accompanying drawings.

FIGS. 1 to 3 show one embodiment of a stencil printing apparatus incorporating a stencil printing apparatus according to the present invention.

In these figures, numeral 1 indicates a cylindrical plate cylinder, which is composed of a cylindrical body with a porous structure, and has a clamping means for locking one end of a stencil printing paper on its outer peripheral surface. 2, is supplied with printing ink from an internally provided ink supply device (not shown), and is rotated counterclockwise in the figure by an electric motor (not shown). A press roller 3 is provided below the cylindrical plate cylinder 1, and the press roller is connected to a press solenoid 4.
The electromagnetic force selectively urges the outer peripheral surface of the cylindrical plate cylinder 1.

A paper feeder 5 is provided on one side of the press roller 3 of the cylindrical plate cylinder 1, and the paper feeder has a paper feeder 6 on which a plurality of sheets of printing paper are loaded. The printing paper placed on the paper stand 6 is taken out one by one by the paper separation roller 7 and the feed roller 8 starting from the top one, and then moved to the cylindrical plate cylinder 1 by the timing row 59 and the guide roller 10.
and the press roller 3, and when passing between these, the printing ink that has passed through the perforations of the stencil printing base paper attached to the outer peripheral surface of the cylindrical plate cylinder 1 is transferred, and this printing ink is It is designed to carry a printed image.

A belt conveyor type sheet discharge device 111 is provided on the other side of the press roller 3. The paper discharging device 11 has a belt conveyor device 12 and a suction box device 13, and the sheet discharging device 11 has a belt conveyor device 12 and a suction box device 13. 12 to convey the paper to a paper discharge table 15.

A base paper storage section 16 is provided on one side of the cylindrical plate cylinder 1. The base paper storage section 16 is configured to accept a continuous sheet of base paper S for stencil printing wound into a roll. As shown in FIGS. 2 and 3, on one side edge of the stencil printing base paper S, a series of feed position detection indicators M are injected with black ink at a constant pitch along the negative side edge. It is printed in.

A plate-making device 17 is located between the base paper storage section 16 and the cylindrical plate cylinder 1.
is provided. The plate-making device 17 is a thermal plate-making device that includes a thermal head 18 and a platen roller 19, and is configured to heat-sensitively perform plate making of the stencil printing paper S supplied from the stencil storage unit 16. It has become. Although the thermal head 18 is not shown in the figure,
A plurality of heating elements are arranged in a horizontal row, that is, at regular intervals in the main scanning direction, and these heating elements selectively generate heat according to image information signals given to them. ing. The platen roller 19 is made of rubber or a rubber-like product, and is selectively driven to rotate by a step motor 27 to selectively feed the stencil printing paper S in the sub-scanning direction.

The plate-making device 17 is provided with an index reading device 40 that reads an index M for detecting the feeding position of the stencil paper S for stencil printing. Index reading device! Reference numeral 40 denotes a light transmission type photoelectric type having a light emitting element 41 and a light receiving element 42 arranged opposite to each other, and outputs an electric signal every time an index M for detecting the feeding position of the stencil printing paper S passes. It is designed to be output.

A base paper cutting device 20 is provided between the plate making device 117 and the cylindrical plate cylinder 1. The base paper cutting device 20 has a fixed blade 21
and a movable blade 22, and the stencil printing base paper S is cut by these two blades.

A base paper stock device 23 is provided between the plate making device 17 and the base paper cutting device 20. Paper stock device! 12
3 is a box-shaped base paper stock section 24 capable of storing stencil printing base paper S having a length corresponding to many sheets of stencil printing base paper in a meander shape, and a base paper stock section 24 from which the stencil printing device 17 is connected.
A base paper feed roller 25 that feeds the base paper S for stencil printing to
and a base paper feed roller 26 that feeds the base paper S for stencil printing from the base paper stock section 24 to the base paper cutting device 20.

Further, a plate discharge device 33 is provided on the other side of the cylindrical plate cylinder 1. The plate discharge device M33 has a movable base paper stripping claw 34.
, a master discharge roller 35 , and a master discharge box 36 .

FIG. 4 shows a control system of a stencil printing apparatus according to the present invention.

The operation of the step motor 27 is controlled by a step motor driver 45, and the step motor driver 45 controls the operation of the step motor 27 based on a clock signal provided from a clock signal generator W146. As a result, platen roller 1
The feeding of the stencil printing base paper S by 9 is controlled.

The operation of the thermal head 18 is controlled by a thermal head driver 47, and the thermal head driver 47 is given an image information signal from an image information III control device 48, and an on-off signal from a NAND circuit 49. When an on signal is given from the NANO circuit 49, the heating elements of the thermal head 18 are activated to generate heat in a predetermined combination based on the image information signal from the image information control signal 48, and in response, an on signal is given from the NANO circuit 49. When the image information control signal 48 is not applied, the heating element of the thermal head 18 stops generating heat even if the image information signal is applied. At this time, the power supply to the heating element of the thermal head 18 may be completely stopped, but the current applied to the heating element may be appropriately limited.

The light receiving element 42 of the index reading device 42 is the comparator 5
The comparator 50 outputs an on signal every time the light receiving element 42 turns off, and outputs the on signal to the OR circuit 51.

The OR circuit 51 outputs an ON signal as a reset signal to the OL terminal of the binary counter 52. The binary counter 52 receives a clock signal common to the step motor 27 from the clock signal generator 46 to its GK terminal, performs an up-count every time the clock signal is input, and when this count number reaches an arbitrary value of the BCD output terminal. When the value determined by the combination is exceeded, all output signals of that output terminal become ON signals. Therefore, when the count value of the binary counter 52 exceeds the set value, the output signal of the NAND circuit 49 is switched from an on signal to an off signal.

A stop or start signal is applied to the OR circuit 51 from a terminal 53, and the binary counter 52 is also reset when plate making is started or when plate making is stopped.

The stencil printing paper S is sent in the sub-scanning direction by a platen roller 19 that is rotationally driven by a step motor 27. During this feeding, the stencil printing paper S passes between the light emitting element 41 and the light receiving element 42 of the index reading device 40, so that the light emitted by the light emitting element 41 is transmitted to the stencil printing paper S.
The comparator 50 outputs an ON signal at a time interval determined by the pitch of the feed position detection indicators M and the feed speed of the stencil paper S. This repeatedly resets the binary counter 52.

When the stencil printing base paper S is being fed normally, the time interval of the ON signal of the comparator 50 is maintained at a predetermined value, and thereby the binary counter 52 is reset at predetermined intervals, and the count value becomes the set value. It will not increase beyond this point. At this time, the output signal of the NAND circuit 49 remains on, and the thermal head 18 performs a regular plate-making operation based on the signal from the thermal head driver 47.

When the stencil printing paper S is not fed normally due to welding of the stencil printing paper S to the thermal head 18, etc., the feeding speed of the stencil printing paper S decreases, and the time interval of the ON signal of the comparator 50 decreases. becomes longer, and therefore the binary counter 52 is not reset within the predetermined time. The count value of the binary counter 52 based on the clock signal increases beyond the set value. At this time, the output signal of the NAND circuit 49 is switched from the on state to the off state, the thermal head driver 47 no longer outputs the image information signal to the thermal head 18, and the trouble display device 54 starts displaying trouble.

At this time, the heat generating action of the heat generating element of the thermal head 18 is substantially stopped, and subsequent plate making in a defective state is stopped, and thermal damage to the heat generating element of the thermal head 18 is avoided. .

In the above-mentioned embodiment, the abnormality detection control was performed using a binary counter, but the present invention is not limited to this, and the control may be performed using a free-run timer or the like of a microcomputer. is also possible.

Further, the index reading device is not limited to a rechargeable type, and may be a magnetic type. When a magnetic index reading device is used, the index for detecting the feed position of the stencil printing paper is It is sufficient if it is printed using magnetic ink.

Although the present invention has been described in detail with respect to specific embodiments above, the present invention is not limited thereto.
It will be apparent to those skilled in the art that various embodiments are possible within the scope of the invention.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of a stencil printing apparatus incorporating a stencil printing apparatus according to the present invention, and FIG. FIG. 3 is an enlarged perspective view showing an index reading portion of the stencil printing apparatus according to the present invention, and FIG. 4 is an electric circuit showing a control system of the stencil printing apparatus according to the present invention. It is a diagram. 1... Cylindrical plate cylinder, 2... Clamp means, 3...
・Press roller, 4...Press solenoid, 5...
Paper feed device. 6... Paper feed table, 7... Paper sorting roller, 8... Feeding roller, 9... Timing roller, 10... Guide roller, 11... Paper discharge device, 12... Belt Conveyor, 13... Suction box device, 14... Separation claw, 15... Paper discharge stand, 16... Original paper storage unit, 17...
... Plate making device, 18... Thermal head, 19...
Platen roller, 20... Base paper cutting device, 21...
Fixed blade, 22...movable blade. 23...Base paper stock device, 24...Base paper stock section. 25... Base paper feed roller, 26... Base paper feed roller, 27... Step motor, 33... Master discharge device. 34... Base paper stripping claw, 35... Master discharge roller, 3
6...Discharge box, 40...Indicator reading device,
41... Light emitting element, 42... Light receiving element, 45...
Step motor driver, 46... Clock signal generator, 47... Thermal head driver, 48...
Image information control device, 49...NAND circuit, 50...
- Comparator, 51...OR circuit, 52...Binary counter. 53...Terminal, 54...Trouble display device enabled
Applicant Riso Kagaku Kogyo Co., Ltd. Representative
Person Patent Attorney Masaki AkashiFigure 2Figure 3

Claims (1)

[Claims] A stencil printing device that performs stencil making while feeding stencil printing paper in one direction, comprising: an index reading device that reads a feed position detection index provided on the stencil printing paper; and an index reading device that reads a feeding position detection index provided on the stencil printing paper Abnormality detection control means for determining whether or not the feeding of the stencil printing base paper is being performed normally based on the index for detecting the feeding position of the stencil printing base paper, and stopping the plate-making operation when the feeding of the stencil printing base paper is not normal. A plate-making device for stencil printing, characterized in that it has the following.