JPS5819555Y2 - Printing device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a printing device that holds the original plate and plate material in close contact with each other so that when printing an image of the original plate onto the plate material, the image of the original plate is not distorted and copied onto the plate material. It is something.

Generally, this type of printing apparatus has an elastic sheet placed on top of the frame material, a transparent plate placed on top of the elastic plate, and a vacuum chamber between the elastic sheet and the transparent plate, which contains the plate material and the original plate. A vacant chamber is formed that also serves as a loading chamber.

During printing, air is removed from between the transparent plate and the elastic sheet, and atmospheric pressure acting on the elastic sheet is used to press the original plate and plate material to the transparent plate, and to bring them into close contact.

However, it is normal for original plates, printing materials, elastic sheets, etc. to have some degree of distortion, and it is normal for ordinary printing materials, etc. to vary in size depending on the situation, so as mentioned above, When the elastic sheet is lifted toward the transparent plate due to degassing, the original plate does not come into contact with the transparent plate from its center, but first comes into contact with the surrounding parts, and then other parts. Even after the air operation is completed, air may be trapped near the center, causing poor adhesion to the thin original plate, plate material, and transparent plate.

This poor adhesion has the disadvantage that when light is irradiated from above the transparent plate, images etc. are printed in a distorted manner on the plate material.

The present invention was developed with the aim of solving the above-mentioned problems in the conventional method, and it is designed to ensure that the adhesion starts from the center of the plate material and then spreads to the periphery. , so that no air pockets are formed in the center or other parts.

Hereinafter, preferred embodiments of the present invention will be explained based on the drawings.

In FIGS. 1 and 2, the printing apparatus is provided with a frame member 10 at the bottom and a transparent plate 12 made of glass or the like thereon.

There is a light source for printing on the transparent plate 12, but this is not shown.

An elastic sheet 14 made of rubber, for example, is installed on the frame material 10, and another elastic sheet 16 is interposed between these 10 degrees 14, and these are sealed at the periphery and screws 18. is fixed by.

The above seal is sealed with adhesive, sticky rubber material, etc. 20 between the elastic sheets 1116, 1116, and 20.
An adhesive 22 is used between the frame member 10 and the frame member 10 .

The latter adhesive 22 is applied at a fairly deep depth and is applied so as to form a gap 24 in the center between the elastic sheet and the frame member.

This gap 24 is set to an appropriate shape such as circular or rectangular, but
The point is that it should be located at the center of the frame member 10 and the elastic sheets 14 and 16.

An annular elastic member 26 is fixed to the periphery of the elastic sheet 14, and when it comes into contact with the transparent plate 12, these 26.
A cavity 28 is formed between the elastic sheet 12 and the elastic sheet 14.

Usually, the transparent plate 12 and the frame member 10 are hingedly engaged, so that the transparent plate can be moved.

The empty chamber 28 serves as both a vacuum chamber and a loading chamber for the plate material 30 and original plate 32.

The original plate 32 is a film on which an image is formed, and the plate material 30 is a metal plate coated with a photosensitive agent, a photosensitive resin plate, an unexposed film, or the like.

The original plate 32 and the plate material 30 are placed one on top of the other with the original plate facing upward, and loaded into the empty chamber 28.

In addition, the vacuum chamber 3 formed between the elastic sea N4.16
Inside 4, there is a cushion sheet 3 made of sponge etc.
A relatively hard and stiff sheet 38, preferably made of cardboard or the like, is interposed on the cushion sheet.

The cushion sheet 36 absorbs the distortion of the elastic sheet 14 during degassing from the empty chamber 28, while the fecal sheet 38
is to equalize the movement of the elastic sheet 14.

Vacuum conduits 40, 42 are connected to the empty spaces 28, 34, respectively, for degassing.

Solenoid valves ■1, V2, and V3 are installed on the way between the vacuum conduit 40 and 42 and the vacuum pump P, and these solenoid valves receive activation signals from limit switches LS, timers T□, T2, etc. It has become.

Next, the operation of the above device will be described.

First, the original plate 32 and the plate material 30 are placed on top of each other and placed on the elastic sheet 14, and then the transparent plate 12 is placed on the original plate 32.
is placed over the annular projection 26 and brought into contact with the annular projection 26.

At this time, the movement of the transparent plate 12 causes the limit switch LS to
issues a signal indicating completion of the setting, and as a result, the vacuum pump P is started, the solenoid valve v1 is closed, and the switching valve v3 is switched to the direction in which the vacuum conduit 42 and the empty space 34 are sucked.

At this time, the solenoid valve v2 is closed.

In this state, when the set time of the timer Tl (for example, 5 seconds) has elapsed, the switching valve V3 is switched in the opposite direction, and air is now evacuated from the empty chamber 28 above.

As degassing from the empty chamber 28 progresses, the center portion of the elastic sheet 16 that is not bonded to the frame material 10 is forced upward by the action of atmospheric pressure, and the upper elastic sheet 1
4. The cushion sheet 36 and the hard sheet 38 are also raised at the center.

As a result, the central portions of the original plate 32 and the plate material 30 are pressed against the transparent plate 12 and brought into close contact with each other.

On the other hand, the timer T2 is started after the timer T□ has elapsed, and the solenoid valve v2 is opened after the set time (for example, 10 seconds) has elapsed.

As a result, atmospheric pressure acts on the entire surface of the elastic sheet 14, and the pressing force spreads from the center to the periphery, and the plate material 30 and original plate 32 are similarly brought into close contact with each other from the center to the periphery. The transparent plate 12 is placed in close contact with the transparent plate 12.

Thereafter, a light source (not shown) installed above the transparent plate 12 is made to emit light, and the image on the original plate 32 is printed onto the plate material 30 without distortion.

After the exposure is completed, the transparent plate 12 is released, but at this time the limit switch LS is activated again to stop the vacuum pump P, and the solenoid valve V1 is opened to release the vacuum state in the empty chamber 28.

Now, according to the present invention, as described above, vacuum adhesion can be started from the center of the printing plate, etc. and spread to the peripheral areas in order, so air can be trapped between the printing plate, original plate, transparent plate, etc. can be made less likely to occur.

Furthermore, since the cushion sheet is interposed to absorb the distortion of the elastic sheet that presses the plate material, etc., the air can be evacuated from the center of the elastic sheet toward the periphery more smoothly.

Therefore, the image of the original plate can be copied onto the plate material without distortion, and the time required for vacuum work can be significantly shortened.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an example of a printing device according to the present invention, and FIG. 2 is a schematic sectional view of the main parts thereof. 10...Frame material, 12...Transparent plate, 14°16...Elastic sheet, 22...
・Adhesive, 24...Gap, 28...Vacancy, 30...Plate material, 32...Original L34
. . . - Vacuum chamber, 36 . . . Cushion sheet, 40. 42 . . . Vacuum conduit.

Claims (1)

[Scope of utility model registration request] An elastic sheet 14 is installed on the frame material 10, and a transparent plate 12 is installed on the elastic sheet, and a vacuum chamber and a loading chamber for plate materials and originals are provided between the elastic sheet and the transparent plate. In a printing device formed with a dual-purpose empty chamber 28, another elastic sheet 16 is interposed between the elastic sheet and the frame material, and this elastic sheet is surrounded by the frame material 10, leaving the center part. Furthermore, a cushion sheet 36 is interposed in the vacuum chamber formed by the elastic sheet and another elastic sheet, and when the original plate 32 and plate material 30 are brought into close contact with the transparent plate, the above-mentioned A printing apparatus characterized in that the vacuum chamber 34 formed by the elastic sheet and another elastic sheet is evacuated before the air is evacuated from the empty chamber 28 into which the original plate and plate material are to be loaded. .