JPH0515041U - Camera for plate making - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a platemaking camera that can easily obtain a master copy when changing the orientation of the master copy in a roll film exposed on a PS plate by a projector. [Structure] In a plate making camera in which the positioning marks 17 of the original document 19 are formed on the roll film 5 when the original is photographed, the positioning marks 17 are formed on the original roll 19 on the roll film 5. It was formed at two positions that are point-symmetrical positions.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a plate-making camera that projects a master copy onto a roll film, and more specifically, a master plate that can be easily dealt with when the orientation of the master copy in the roll film exposed on a PS plate by a projector is changed. The present invention relates to a platemaking camera that can obtain a manuscript.

[0002]

[Prior Art]

 Conventionally, a photoengraving system for producing a printing plate for offset printing has generally been 1 × imaging and contact (1 ×) exposure. That is, a plate is photographed in a lithographic film at the same size, and the plate is contact-exposed on a PS plate (referring to all photosensitive materials for offset printing plates), and the plate is developed to obtain a plate. In the case of a page object, as shown in FIG. 4, the number of imprinted films 33 of the block copy is set on one backing sheet 31 (8 for 8 pages, 16 for 16 pages), and a predetermined number. The surfaces are lined up in order and in a predetermined direction, and then exposed, and the PS plate is exposed in close contact. However, in this conventional photoengraving system, the original plate is photographed at the same size on the lith film, and the PS plate is further photographed at the same size, so that the cost of the film is high, and the space for storing these is high. The cost is also high, and the workability of the imposition work is poor, and there is the problem of having to rely on skilled workers.

From such a background, a reduction / enlargement photoengraving system has been proposed and put into practical use. The reduced-enlarged photo engraving system first reduces the size of the roll film in sequence by observing the signatures, and by setting the orientation and using the engraving camera to continuously reduce the images. On the other hand, a projector is arranged on the PS plate so as to be movable in two orthogonal directions, and the developed roll film is set on the projector. Then, while automatically moving the projector on the PS plate and automatically sending out the roll film, the desired master copy original is continuously and continuously enlarged to a desired position on the PS plate, and the exposure ( Then, the exposed PS plate is developed to obtain a printing plate. The present applicant has already applied for Japanese Utility Model Laid-Open No. 1-113240 and Japanese Utility Model Laid-Open No. 1-242832 with regard to this plate-making camera and projector. In such a reduced-magnification photoengraving system, it is of course necessary to accurately stop the projector at a predetermined position on the PS plate in order to accurately expose the master copy document at the predetermined position on the PS plate. It is necessary to accurately stop the block copy document at a predetermined position in the projector.

Therefore, in order to accurately stop the master copy document at a predetermined position in the projector, conventionally, for example, when a notch is provided in the aperture frame of the plate making camera and the master plate is photographed by the plate making camera, As shown in FIG. 5, positioning marks 37 for the original document 35 are formed on the roll film 39 in advance. After developing the roll film 39, when projecting the original document 35 with the projector, the sensors installed near the aperture frame of the projector detect the front end and the rear end of the positioning mark 37, respectively. The feed motor of the roll film 39 is decelerated when the leading edge is detected, the motor is stopped when the trailing edge is detected, and the original document 35 is accurately aligned with the aperture frame and stopped.

[0005]

[Problems to be solved by the device]

 However, in such a conventional method, since the positioning mark 37 is formed on one side of the master copy original 35, for example, when the user fails and wants to reverse the upside-down direction of one of the master originals 35A. , There was the following defect. First, as shown in FIGS. 5 (A) and 5 (B), the original copy 35A at that portion is cut out. Next, when the top and bottom are turned upside down, the photography of the block copy is re-arranged and developed so that the positioning mark 37 is located at the correct position with respect to the copy sheet original 35. Next, as shown in FIGS. 5 (C) and (D), the developed original document 35A-1 is adhered to the cut portion with a splice tape. That is, the conventional plate-making camera is inconvenient because it is necessary to retake the original image again when the original document is turned upside down. The present invention has been devised in view of the above circumstances, and an object of the present invention is to make a plate-making camera capable of changing the orientation of a master copy original on a roll film without re-imaging the master copy. To provide.

[0006]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention provides a plate making camera which forms a mark for positioning a master copy document on a roll film at the time of photographing a master copy, and the positioning mark is provided on the roll film. It is characterized in that it is formed at two points that are point-symmetrical with respect to.

[0007]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a rear view of the central portion of the plate-making camera according to the embodiment with the back cover opened. Reference numeral 1 is a camera body, 3 is an aperture frame for controlling the screen size, and a pair of parallel flat transparent substrates 7 for securing the flatness of the roll film 5 are held by a holding frame 9 behind the aperture frame 3. There is. The roll film 5 is passed from the sending-side cartridge chamber 11 side through the parallel flat transparent substrate 7 to the winding-side cartridge chamber 13 side, and is wound one frame at a time at the winding-side cartridge chamber 13 side every time the photograph is taken. Taken.

The aperture frame 3 is provided with a rectangular notch 15 for forming a positioning mark for a block copy document. The notches 15 are provided at the upper edge and the lower edge of the aperture frame 3, respectively, at two positions which are point-symmetric with respect to the block image to be photographed, that is, the block document. Since the present embodiment has the above-described structure, when the master plate is photographed, the positioning marks are imprinted together with the master plate at two points that are point-symmetric with respect to the master plate to be photographed, and the roll after development is processed. As shown in FIG. 2, on the film 5, an original master copy 19 having positioning marks 17 formed on the upper edge and the lower edge can be obtained. Then, when the developed roll film 5 is set in a conventional projector and the master copy document 19 is projected on the PS plate, one of the two positioning marks 17 for positioning the mark 17 (in this embodiment, in the figure, The positioning mark 17) on the upper side is detected by the sensor, the feed motor of the roll film 5 is controlled, and the original document 19 is accurately aligned with the aperture frame 3 and stopped in the projector. Then, a desired master copy document 19 is automatically and continuously enlarged and exposed (with a surface) at a desired position on the PS plate, and the exposed PS plate is developed and used as a printing plate. Will be completed.

Here, when changing the orientation of one of the original copy originals 19A in the developed roll film 5, as shown in FIG. 2B, the original copy originals 19A in that portion is cut off, and As shown in C) and (D), attach the splice tape with the top and bottom turned upside down. That is, since the positioning marks 17 for positioning the block copy document 19A in the projector are provided at two points that are point-symmetric with respect to the block copy document 19A, even if the upside-down orientation is reversed, A master copy document 19A in which the positioning mark 17 is located at the correct position is obtained. Therefore, when the direction of the top and bottom is changed, it is not necessary to change the direction of the top and bottom and re-photograph the block copy as in the conventional case, and it is possible to easily deal with it.

In the embodiment, the notch 15 is formed in the aperture frame 3 and the positioning mark 17 is formed by this notch 15. However, the means for attaching the positioning mark 17 is arbitrary, for example, A positioning marker is imaged by a light-emitter type fiber projector for each photographing, and as shown in FIG. 3, the mark is positioned at two points which are point-symmetric with respect to the master copy original 19 at a position apart from the master copy original 19. You may make it attach the use mark 21.

[0011]

[Effect of the device]

 As is clear from the above description, according to the master copy original imaged by the plate making camera according to the present invention, the orientation of the top and bottom of the master original document in the roll film exposed on the PS plate by the projector is changed. In this case, it is not necessary to retouch the block copy, and it will be easier to deal with it.

[Brief description of drawings]

FIG. 1 is a rear view of a central portion of a plate making camera according to an embodiment with a back cover opened.

2 (A), (B), (C), and (D) are explanatory views of a roll film photographed by the plate-making camera according to the present embodiment.

FIG. 3 is an explanatory diagram of a roll film photographed by the plate making camera according to the present embodiment.

FIG. 4 is an explanatory diagram of sticking a block copy document on a mount.

5 (A), (B), (C), and (D) are explanatory views of a roll film photographed by a conventional plate-making camera.

[Explanation of symbols]

 1 Camera body 3 Aperture frame 5 Roll film 15 Notch 17,37 Positioning mark 19,37 Plate original

Claims (1)

[Scope of utility model registration request] 1. A plate making camera for forming a positioning mark of an original copy on a roll film at the time of photographing the original, wherein the positioning mark is located on the roll film at a point symmetrical position with respect to the original copy. A plate-making camera characterized in that it is formed in two places.