JPH048786B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an exposure method and an apparatus thereof that can be employed in a plate-making machine commonly called a vacuum contact printer.

[Conventional technology]

The basic principle of the plate-making process in the Printing Photolithography Department and Industrial Photography Department is that a photosensitive material is overlaid on an original plate in which predetermined patterns such as drawings and letters are drawn in black on a transparent polyester film treated with silver salt and then exposed to light. Based on. In order to achieve this basic principle, the vacuum contact printer described above is equipped with a translucent exposure plate and a blanket placed over the exposure plate, and the above-mentioned original plate and photosensitive material are placed between the exposure plate and the blanket. The structure is such that the materials are overlapped and sandwiched together, and then exposed to light. After exposure, the original plate and photosensitive material are removed from between the exposure plate and the blanket and transferred to the next process, so the blanket must be attached to and removed from the exposure plate as necessary. There are two attachment/detachment methods in this case: a frame development method and a take-up roller method. The frame development method allows the blanket to be attached to and removed from the exposure plate in a single-opening manner. In the take-up roller system, the blanket can be applied to the exposure plate by being fed out from the take-up roller, and can be removed from the exposure plate by being rewound onto the take-up roller.

Regardless of which method is used, in order to faithfully expose the image information contained in the original plate onto the photosensitive material, the original plate and the photosensitive material sandwiched between the exposure plate and the blanket must be exposed during the exposure time. It is desirable that it be in close contact with the entire surface without any gaps.

Therefore, conventionally, blankets are made of non-transparent flexible materials such as rubber and cloth.
A method is adopted in which the space between the blanket and the exposure plate is sucked before exposure and the blanket is deformed to bring the overlapping original plate and photosensitive material into close contact with each other, followed by exposure. Ta.
However, even if such a method is adopted, it is difficult to ensure that the original plate and the photosensitive material are brought into close contact with each other over the entire surface without any gaps, and even if it were possible, it would require a larger suction force and longer suction time than necessary, which is not practical. Not on point. In order to solve this problem, a handling roller is rolled on the blanket at the same time as the space is suctioned, and the handling action at that time expels the air between the original plate and the photosensitive material and brings them into close contact. , followed by exposure may be adopted.

However, in vacuum contact printers that employ this method, the above-mentioned take-up roller type requires a combination of the action of feeding the blanket from the take-up roller and the rolling action of the handling roller due to the need to shorten the suction time. A configuration is adopted in which both are performed in parallel. For this reason, the handling action by the handling roller is performed before the blanket is in a fixed position relative to the exposure plate, which causes a misalignment between the original plate and the photosensitive material, making it difficult to perform subsequent exposures faithfully. This could be a cause of difficulty. In addition, in vacuum contact printers that use either the frame development method or the take-up roller method, if a diazo-based photosensitive material is used, gases generated from the photosensitive material as the exposure progresses Therefore, it is unavoidable that a gap will be created between the original plate and the photosensitive material. Therefore, when exposing diazo and photosensitive materials, conventionally, no matter how perfect the suction and handling are before exposure, it is impossible to ensure complete contact between the original plate and the photosensitive material. Difficulties were encountered in ensuring that this was maintained during the exposure time.

[Problem that the invention seeks to solve]

The problem to be solved by this invention is to prevent the misalignment between the original plate and the photosensitive material which are sandwiched between the exposure plate and the blanket, and when a diazo type photosensitive material is used as the photosensitive material. Even if gas is generated from the sensitive material as the exposure progresses, the original plate and the sensitive material must be kept in close contact over the entire surface during the entire exposure time.

[Means for solving problems]

The means for solving the above problem is to apply the above-mentioned handling action to the original plate and photosensitive material sandwiched between the exposure plate and the blanket by the handling roller during the exposure time or not. is to add this handling effect.

[Operation] It is necessary to keep the original plate in close contact with the photosensitive material during the exposure time, and the exposure is carried out with the original plate and photosensitive material completely sandwiched between the exposure plate and the blanket. Even if the above-mentioned handling action is performed during the exposure time, the original plate and the light-sensitive material are securely brought into close contact with each other without causing any positional deviation. Furthermore, even if gas is generated from the sensitive material as exposure progresses due to the use of a diazo sensitive material, the above-mentioned handling action that takes place during the exposure time will also cause the gas to be mixed between the original plate and the sensitive material. The particles are immediately expelled from the gap between the particles, and the original plate and photosensitive material remain in reliable contact throughout the entire exposure time.

〔Example〕

In the vacuum contact printer illustrated in Fig. 1,
1 is a case containing a light source, 2 is an exposure plate bordered by a frame 21, 3 is a blanket, and 4 is a handling roller. The blanket 3 is made of a non-transparent flexible material such as rubber or cloth, and is stretched over the lower surface of the frame 5. Further, the frame body 5 is provided with a pair of running guide rails 61 and a pair of lateral vibration prevention rails 62 on the left and right sides. Both ends of the handling roller 4 are supported by the running guide rail 61 via the pressing force adjustment mechanism 7 and the running roller 81. A running roller 8 is provided on the lateral vibration prevention rail 62.
A lateral vibration prevention roller 82, which is paired with 1, follows the movement. Furthermore, one location of the running drive belt 100 is fixed to a protrusion 9 provided on the pressing force adjustment mechanism 7.

As schematically illustrated in FIG. 2, one end of the frame 21 and the frame 5 is rotatably attached to the case 1, and the frame 21 and the frame 5 are rotatably attached to the case 1 with the attachment portion 9 as a fulcrum.
The frame bodies 5 can each be moved up and down in a single-opening manner. When both the frame body 21 and the frame body 5 are moved down, the blanket 3 is placed on the exposure plate 2 as shown in FIG.

Further, as shown in detail in FIG. 3, the pressing force adjustment mechanism 7 includes a bearing 72 built in the case 71,
A holding plate 7 comprising an adjustment screw 73 screwed into the case 71 and a guide rod 74 projecting upward.
5, a movable plate 76 rotatably attached to the lower end of the adjusting screw 73, and a compression spring 77 interposed between the movable plate 76 and the holding plate 75, and the rotation axis of the handling roller 4 is attached to the bearing 72. 41 is supported. According to such a pressing force adjustment mechanism 7,
When the adjustment screw 73 is screwed in and out of the case 71, the elastic force of the compression spring 77 changes accordingly, and this elastic force acts on the handling roller 4 via the holding plate 75 and the bearing 72, so that the blanket The pressing force of the handling roller 4 against the roller 3 is adjusted to increase or decrease.

FIG. 4 schematically shows the drive system of the handling roller 4. As shown in FIG. This drive system includes a pair of left and right running drive belts 100, a motor 110 and a motor 1 as drive sources.
a rotation transmission mechanism 120 for transmitting forward and reverse rotation of the motor 110 to the running drive belt 100; and a limit switch 1 for switching the rotation direction of the motor 110.
It is equipped with 31,132. According to such a drive system, when the motor 110 is started, the handling roller 4 rolls on the blanket 3 (see FIGS. 1 and 3) and reciprocates as shown by arrow A in FIG. do. In this case, the motor 110 is controlled to operate at all times during the exposure time, and is controlled to operate as necessary before exposure. A control mechanism (not shown) for performing such operations can be easily constructed using a microcomputer unit (microcomputer). Moreover, it can be easily configured without using a microcomputer or by using other control elements such as a timer.

Note that the space S between the exposure plate 2 and the blanket 3 shown in FIG. It is deformed and brought into close contact with the exposure plate 2. Therefore, when the space S is sucked from the state where the original M and the sensitive material F are overlapped and sandwiched between the exposure plate 2 and the blanket 3 as shown in FIG. 1, the original M as shown in FIG. and sensitive material F are exposure plate 2
and the blanket 3.

Next, the effect will be explained.

When exposure is performed from the state shown in FIG. 3 above, during the exposure time, the handling roller 4 constantly presses the blanket 3 as shown in FIG. 5 due to the action of the drive system shown in FIG. Roll with. In this case, depending on the exposure time, the handling roller 4 will repeatedly roll back and forth over the blanket 3.
Therefore, during the exposure time, the blanket 3 is constantly handled by the handling roller 4, and accordingly, a handling action is applied to the sensitive material F superimposed on the original M, so that the original M shown in FIG. Sensitive material F
If there is a gap between them, the two will come into close contact and that gap will disappear. Furthermore, even if a gas is generated from the photosensitive material F as the exposure progresses due to the use of the diazo-based photosensitive material F, and a gap is created, the gas is immediately expelled from the gap between the two, and both is in close contact.

Further, in the state shown in FIG. 3, the original M and the photosensitive material F are reliably positioned by the pressing force between the exposure plate 2 and the blanket 3, so that the handling roller 4 is moved on the blanket 3 during the exposure time. Even if they are rolled and handled, there is no risk of misalignment between them.

Incidentally, the blanket 3 may be handled by the handling roller 4 by operating a drive system before exposure. When this action is performed simultaneously with the suction of the space S between the exposure plate 2 and the blanket 3, the efficiency of exhausting air from the space S is improved, so there is an advantage that the suction time can be shortened.

〔Effect of the invention〕

As is clear from the above, according to the present invention, the close contact between the original plate and the photosensitive material is reliably maintained during the exposure time, so that the image information contained in the original plate can be faithfully exposed to the photosensitive material. become. In addition, the action of handling the blanket with the handling roller must be performed during the exposure time when the original plate and photosensitive material are held under pressure by the exposure plate and the blanket, but it is not always necessary to handle the blanket before exposure. Since there is no need for any handling action, the advantage is that it can prevent misalignment between the original plate and the photosensitive material, not only in frame development type vacuum contact printers but also in take-up roller type vacuum contact printers. There is.

[Brief explanation of drawings]

Fig. 1 is a vertical cross-sectional view showing the main parts of a vacuum contact printer employing an exposure device according to an embodiment of the present invention, Fig. 2 is a schematic side view showing how the frame is attached to the case, and Fig. 3 is a pressing force. A vertical sectional view showing the details of the adjustment mechanism and the state in which the original plate and the photosensitive material are held under pressure, FIG. 4 is a perspective view schematically showing the drive system, and FIG. 5 is a schematic plan view for explaining the operation of the handling roller. It is. 2... Exposure plate, 3... Blanket, 4... Handling roller, S... Space between exposure plate and blanket, M... Original plate, F... Photosensitive material.

Claims (1)

[Scope of Claims] 1. The space between the exposure plate and the blanket sandwiching the original plate and the photosensitive material stacked on top of each other is sucked and the blanket is deformed so that the original plate and the photosensitive material are separated by the exposure plate and the blanket. An exposure method in which exposure is performed after holding an original plate under pressure, and the exposure method is characterized in that a blanket is handled during the exposure time to maintain a state of close contact between an original plate and a photosensitive material. 2. An exposure plate and a flexible blanket that sandwich the overlapping original plate and photosensitive material, and a suction mechanism that sucks the space between the exposure plate and the blanket;
An exposure apparatus comprising: a handling roller that rolls on the blanket while pressing the blanket; and a control mechanism that rolls the handling roller on the blanket during exposure time.