JPS6327696B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal copying apparatus, and more particularly, a polymer of an original sheet and a thermal copying sheet is sandwiched between a light transmitting plate and a pressing plate, and the thermal copying is carried out from the side of the light transmitting plate. The present invention relates to a press plate of a thermal copying device configured to irradiate light onto the original sheet through the sheet.

An original sheet comprising a light transmitting plate provided in a light irradiation window and a pressing plate provided opposite to the light transmitting plate, and having a light absorbing image portion formed by the light transmitting plate and the pressing plate; The polymer is sandwiched between a light-transmitting thermal copying sheet and a light beam is irradiated from the light-transmitting plate side through the thermal copying sheet toward the original sheet, so that the image area of the original sheet absorbs the light energy. There is a known thermal copying apparatus configured to provide a copied image by perforating the thermal copying sheet or changing the image area due to changes such as perforation, discoloration, shrinkage, etc. due to an increase in the temperature of the image area caused by the heating. In addition to producing copies, it is also used as a plate-making device for thermally copying stencil paper for stencil printing.

In the thermal copying apparatus described above, in order to obtain high-resolution, beautiful, and high-quality copied images,
It is required that the original sheet and the thermal copying sheet are in uniform contact with each other so that the heat absorbed by the image area of the original sheet is uniformly and well transferred to the thermal copying sheet. While the press plate is made of a rigid body such as a plate, the press plate is made of a material having flexibility and rubber-like elasticity like a sponge. The pressing plate becomes extremely hot, albeit momentarily, even when exposed to flash light from a xenon discharge tube or the like, so the pressing plate is required to have excellent heat resistance from the viewpoint of durability. In order to effectively utilize the thermal energy of the light beam for thermal copying, it is preferable that the surface of the pressing plate facing the light transmitting plate not only be light reflective but also have excellent thermal insulation properties.

When a thermal copying sheet without a white paper mount on one side (back side) is used in plate making by thermal perforation copying of stencil printing base paper, the size of the original sheet is smaller than the size of the thermal copying sheet. Then, the thermal copying sheet directly contacts the surface of the opposing surface portion of the pressing plate, and therefore, the surface of the pressing plate has good releasability so that the thermal copying sheet does not stick to the surface of the pressing plate. In this case, if dust or the like is attached to the surface of the pressing plate, the dust may absorb light on the surface, causing unnecessary dots on the thermal copying sheet. In particular, when the thermal copy sheet is used as a base paper for stencil printing, the dotted copied image forms dotted printed images called pinholes in the margins of the printing paper. This makes it difficult to obtain beautiful, high-quality prints. As mentioned above, the effects of dust adhering to the surface of the press plate are particularly noticeable on thermoplastic synthetic resin film units or thermoplastic synthetic resin films in which thermosensitive copying sheets are stretched, such as thermosensitive copying sheets used as base paper for stencil printing. In this case, even if the dust attached to the surface of the press plate is so small that it is difficult to see it with the naked eye, even if it is light-absorbing. For example, it is sufficiently effective to produce heat-sensitive perforations in the film, and the perforations thus formed in the film are enlarged due to the stretching of the film and are sufficiently large to be visible to the naked eye. There is a tendency to expand. Therefore, it is preferable that dust and the like hardly adhere to the surface of the opposing surface of the pressing plate, and that even if dust and dirt are formed, it can be wiped off relatively easily.

The surface material of the press plate of a thermal copying device that has been commonly used in the past does not meet all of the above requirements, and in many cases does not have sufficient removability.
In addition, it is easily soiled by dust and the like, and it is difficult to wipe off the dirt.

The present inventor conducted trial-and-error experimental research using various surface materials in order to find a preferable surface material for the press plate that satisfies all of the above-mentioned requirements.
As a result, the inventors of the present invention were able to find one of the preferable surface materials for a press plate that satisfies all of the above-mentioned requirements.

The object of the present invention is to provide a thermal copying apparatus equipped with a preferable pressing plate surface material that satisfies all of the above-mentioned requirements found through the above-mentioned experimental studies.

According to the present invention, this object includes a light transmitting plate provided on a light irradiation window and a pressing plate provided opposite to the light transmitting plate, and the light transmitting plate and the pressing plate prevent light from being emitted. A thermal copying machine configured to sandwich a polymer of an original sheet having an absorbent image area and a thermal copying sheet, and to irradiate a light beam from the light-transmitting plate side through the thermal copying sheet and toward the original sheet. This is achieved by a thermosensitive copying device in which the surface of the pressing plate facing the light transmitting plate is coated with fluororesin and is made of a woven fabric having air permeability between the front and back sides. .

The woven fabric is provided on the opposing surface of the pressing plate, which is based on an elastic body having flexibility and rubber-like elasticity like a sponge. The woven fabric does not impair its rubber-like elasticity, and since its surface is coated with fluororesin, it has excellent heat resistance and heat insulation properties.Moreover, the woven fabric has good releasability due to the fluororesin coating. In addition, since the contact area with the thermal copying sheet is smaller than that of a smooth flat fluororesin coated sheet, the thermal copying sheet does not adhere strongly to the woven fabric, and this woven fabric has excellent releasability. ing. In addition, as mentioned above, the woven fabric has a small contact area with the thermal copying sheet and forms an insulating air area between the press plate and the thermal copying sheet.
The heat insulation between the sheet and the thermal copying sheet is further improved, and the energy of the light rays directed toward the polymer from the light-transmitting plate side is efficiently and effectively used for thermal copying, resulting in clear and high-resolution images. It becomes possible to obtain a duplicate image or to reduce the amount of irradiation light.

As mentioned above, the mesh of the woven fabric used as the surface material of the pressing plate is preferably 40 or more and 100 or less. If the mesh is 100 or more, the above-mentioned effect cannot be obtained, and the mesh is too thin.
If it is less than 40, the resolution of the copied image will deteriorate.

Fluorocarbon resin has an extremely low coefficient of friction and high surface smoothness, so woven fabrics coated with fluorocarbon resin are difficult for dust to adhere to the surface, and even if dirt occurs, it will not be impregnated. , dirt can be easily wiped off with a cloth or the like.

The fibers of the woven fabric may be those that can withstand the temperature during coating with fluororesin and have flexibility and pliability, such as glass fibers,
There are carbon fibers, polyamide fibers, and yarns thereof.

Furthermore, since the woven fabric has air permeability between the front and back surfaces, even if the moisture and oil components contained in the document sheet evaporate during exposure, those vapors will quickly pass through the woven fabric. This prevents the adhesion between the original sheet and the thermal copying sheet from decreasing due to vapor pressure, and in particular, voids in solid images are avoided, making it possible to obtain high-resolution, good-quality copied images.

Further, the woven fabric may be a plain weave or special weave of fibers coated with a fluororesin in advance, or a fabric made of plain weave or special weave of fibers coated with a fluororesin.

The invention will now be described in detail by way of example embodiments with reference to the accompanying drawings.

The accompanying figures show one embodiment of a thermal copying apparatus according to the present invention. In the figure, 1 indicates a light source box, and the light source box is provided in a frame F and has a light irradiation window opened at the top, and the light irradiation window is made of a transparent glass plate or the like. A light transmitting plate 2 is provided. The light source box 1 has inside thereof a light source device 3 such as a xenon discharge tube and a reflecting mirror 4, and is configured to emit light toward a light transmitting plate 2.

A pressing plate 5 is fixedly arranged above the light transmitting plate 2. The pressing plate 5 is fixed to an upper bar C attached to the upper part of the frame F so as to be openable and closable, and includes a cushion member (base) 6 having flexibility and rubber-like elasticity like a sponge. has a lower bottom surface facing the light transmitting plate 2, and the lower bottom surface is covered with a cover sheet 7.

That is, the surface of the pressing plate 5 facing the light transmitting plate 2 is constituted by a cover sheet 7, and the cover sheet is constituted of a woven fabric coated with fluororesin. The woven fabric constituting the cover sheet 7 is
Glass fibers, carbon fibers, polyamide fibers, or their yarns coated with fluororesin in plain weave or special weaving, or the above-mentioned fibers previously coated with fluororesin or their yarns in plain weave or special weave. It is a white woven fabric with a mesh size of about 40 to 100, and has breathability between the front and back sides.

The light source box 1 is supported by a frame F so as to be movable in the vertical direction as shown in the figure, and a cam holder 8 fixed to the light source box engages a cam 9, and as the cam rotates, the light source box 1 moves as shown in the figure. As shown in the figure, there is a lowered position where the light transmitting plate 2 is away from the cover sheet 7 of the pressing plate 5, and a rising position where the light transmitting plate 2 is moved upward in the figure from the lowered position and the light transmitting plate 2 is pressed against the cover sheet 7 of the pressing plate 5. It is designed to be driven between positions.

The cam 9 is drivingly connected to an electric motor 10, and is driven to reciprocate and rotate by the electric motor.

On one side of the light source box 1 is a document insertion table 11.
However, thermal copy sheet storage sections 12 are provided below the document insertion table 11, and each storage section stores a continuous sheet of thermal copy sheets S wound around a bobbin 13. The thermal copy sheet S stored in the thermal copy sheet storage section 12 is guided by a pair of guide rollers 14 and sent onto the light transmitting plate 2 of the light source box 1. The top surface of the document sheet O inserted between the document sheet O and the document sheet O is engaged with the document sheet O inserted between the document sheet O and the document sheet O inserted between the document sheet O and the document sheet O inserted between the document sheet O and the document sheet O.

The lower roller 14a of the guide roller pair 14 is attached to the frame F.
The upper roller 14b is rotatably supported more directly, whereas the upper roller 14b is rotatably supported by a lever 17 that is pivotally supported on the upper cover C by a pivot 16, and the lever 17 is integrally supported with the lever 17. The provided engagement piece 18 is adapted to selectively engage with one end of a push-up lever 20 rotatably attached to the frame F by a pivot 19, and the lever 20
When the solenoid 21 drivingly connected to the lever is not energized, the spring 22 rotates the lever 17 in the counterclockwise direction from the rotational position shown in the figure by the spring force of the spring 22. The upper roller 14b is separated from the lower roller 14a so that the original sheet O can be easily inserted between the light transmitting plate 2 and the pressing plate 5, whereas the solenoid 21 is not energized as shown in the figure. At this rotational position, the upper roller 14b is disengaged from the engagement piece 18 and is allowed to freely engage the lower roller 14a due to its own weight.

On the other side of the light source box 1, a pair of feed rollers 24 for feeding thermal copy sheets, a cutter device 27, and a thermal copy sheet discharge table 30 are provided.

The feed roller pair 24 has a lower roller 24 a rotatably attached to the frame F and an upper roller 24 b rotatably attached to the upper cover C. The lower roller 24 a is driven by an electric motor by a belt type transmission 25 26, and is selectively rotated counterclockwise in the figure by the electric motor.

The cutter device 27 has a rotary blade 27a rotatably attached to the frame F and a fixed blade 27b attached to the upper cover C. The lower roller is selectively rotated as the lower roller rotates, and cuts the thermal copying sheet S in cooperation with the fixed blade 27b.

The pair of feed rollers 24 is located below the light transmitting plate 2, so that the thermal copying sheet S that has passed over the light transmitting plate 2 passes through the separating protrusion 23 attached to the side edge of the light source box 1 and passes through the pair of feed rollers 24. By moving toward the ridge, the separation protrusion 23 is bent downward at a relatively large angle in the figure. A document sheet discharge guide plate 32 is attached to the upper cover C and defines a document sheet discharge passage 31 extending diagonally upward from a portion corresponding to the protrusion 30.

Next, the operation of the thermal copying apparatus constructed as described above will be explained.

The original sheet O to be subjected to thermal copying is placed on the original placing table 11 with the original image side facing downward, and the thermal copying sheet S, which has been placed on the light transmitting plate 2 in advance, is guided to the original insertion table. and the cover sheet 7 of the pressing plate 5.

When a predetermined amount of original sheet O is inserted and its leading end is positioned near separation protrusion 23, cam 9 is rotated clockwise in the figure by electric motor 10, and light source box 1 is thereby raised. , manuscript sheet O
Light transmitting plate 2 of the polymer of and thermal copying sheet S
The portion between the press plate 5 and the press plate 5 is pinched and pressed by the two, and in this pinched state, the light source 3 emits light, so that the light rays are transmitted through the light transmitting plate 2 and the thermal copying sheet S. When the original image surface of the original sheet O is irradiated and the light-absorbing image area of the original sheet is heated, a hole having the same shape as the image area is thermally perforated in the thermal copying sheet S. After the light source 3 emits light, the cam 9 is rotated counterclockwise in the figure by the electric motor 10, so that the light source box 1 is
descends, the light transmitting plate 2 is separated from the pressing plate 5,
The clamping pressure between the original sheet O and the thermal copy sheet S is released. Next, the feed roller pair 2 is
The lower roller 24a of No. 4 is driven counterclockwise in the figure, thereby feeding the thermal copying sheet S by one exposure, and at the same time feeding the original sheet O.
is the original discharge sheet path 3 which is peeled off from the thermal copying sheet S and guided to the original sheet discharge guide plate 32.
It starts to move towards 1.

As mentioned above, in the exposure for thermal copying, the polymer of the original sheet O and the thermal copying sheet S is exposed on the light transmitting plate 2.
and a pressing plate 5, and the surface of the pressing plate 5 facing the light transmitting plate 2 is constituted by a cover sheet 7 made of a woven fabric coated with fluororesin. Therefore, due to the heat insulating properties of the cover sheet 7, the light rays emitted by the light source 3 are effectively used for thermal copying, and a high-resolution thermal copy image (perforated image) is formed on the thermal copy sheet S. .

If the width of the original sheet O is equal to or larger than the width of the thermal copy sheet S, the thermal copy sheet S will not come into direct contact with the pressing plate 5. However, if the width of the original sheet O is smaller than the width of the thermal copying sheet S, the thermal copying sheet S will come into direct contact with the pressing plate 5 at its side edges, but the contact surface will be coated with fluororesin. Since the cover sheet 7 is made of a textured woven fabric, it has good releasability, and the thermal copying sheet S does not strongly adhere to its surface. In addition, the sheet cover 7 is not easily stained due to its material, and beautiful thermal copies can be obtained without unnecessary copied images due to dirt.

In addition, since the woven fabric constituting the cover sheet 7 has air permeability between the front and back sides, even if the moisture and oil contained in the original sheet O evaporates during the above-mentioned exposure, those vapors do not evaporate. It quickly diffuses through the woven fabric, thereby avoiding a decrease in the adhesion between the original sheet O and the thermal copying sheet S due to vapor pressure.

The pressing plate 5 is attached to an upper cover C that can be opened and closed with respect to the frame F, and when the upper cover C is in the open position, the cover sheet 7 of the pressing plate 5 is opened to the outside and can be wiped off. It is becoming easier to perform.

Although the present invention has been described in detail with respect to specific embodiments above, it is understood that the present invention is not limited thereto and that various embodiments can be made within the scope of the present invention. This will be obvious to businesses.

[Brief explanation of the drawing]

The attached figure is a schematic longitudinal sectional view showing one embodiment of a thermal copying apparatus according to the present invention. 1...Light source box, 2...Light transmission plate, 3...
Light source, 4...Reflector, 5...Press plate, 6...Cushion member, 7...Cover sheet, 8...Cam fluoro rod, 9...Cam, 10...Electric motor, 1
DESCRIPTION OF SYMBOLS 1... Original insertion table, 12... Thermal copy sheet storage section, 13... Bobbin, 14... Guide roller pair, 1
6... Pivot, 17... Lever, 18... Engagement piece,
19... Pivot, 20... Push-up lever, 21...
Solenoid, 22... spring, 23... separation protrusion,
24...Feed roller pair, 25...Belt transmission device, 26...Electric motor, 27...Cutter device, 28
. . . clutch, 29 . . . transmission device, 30 . . . thermal copy sheet ejection table, 31 . . . original sheet ejection passage, 32 . . . original sheet ejection guide plate.

Claims (1)

[Scope of Claims] 1. A light transmitting plate provided in a light irradiation window and a pressing plate provided opposite to the light transmitting plate, wherein a light absorbing image is generated by the light transmitting plate and the pressing plate. In a thermal copying apparatus configured to sandwich a polymer of an original sheet and a thermal copying sheet having a part and to irradiate a light beam from the light transmitting plate side to the original sheet via the thermal copying sheet. 2. A thermal copying apparatus, characterized in that a surface of the pressing plate facing the light transmitting plate is coated with a fluororesin and is made of a woven fabric having air permeability between the front and back sides. 2. The thermal copying apparatus according to claim 1, wherein the woven fabric is a woven fabric of 40 to 100 meshes.