JP2630788B2 - Photo engraving system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a photoengraving system, and more particularly, to a reduced-enlarged photoengraving system suitable for printing pages.

"Prior art and its problems" Conventionally, a photoengraving system for producing a printing plate for offset printing has generally used the same-magnification photography and close contact (equal-magnification) exposure. That is, a plate is photographed at the same magnification on a lithographic film, and this is exposed in close contact on a PS plate (which refers to all of the photosensitive material to be a printing plate for offset printing), and developed to obtain a printing plate. In the case of a page, on a sheet of paper, the number of imprinted films on the board should be imposed (8 sheets for 8 sheets, 16 sheets for 16 sheets).
The sheets are arranged in a predetermined order and imposed, and this is closely exposed to a PS plate. However, in this conventional photoengraving system, the cost of the film is high because the underprint is photographed at the same magnification on the squirrel film and then photographed at the same magnification on the PS plate, and the space and cost for storing these are also high. There was a problem of high. Furthermore, the workability of the imposition work is poor, and the skilled person must rely on them.

Against this background, some reduction / enlargement photoengraving systems have been proposed and put into practical use, in which the composition is reduced in size, enlarged and automatically exposed (imposed) on the PS plate. However, the conventionally proposed reduction / enlargement photoengraving system has a reduction photographing camera capable of changing a reduction magnification according to a document size, and a projection magnification corresponding to a photographed image of a composition. It is provided with a magnifying photoengraving machine separately, and the device is large and expensive.

In addition, this conventional system is applicable to dictionaries, novels,
It is limited to printed matter consisting only of line drawings such as telephone directories and comics. In other words, the technical idea of this conventional system is
Regardless of the size of the original, a fixed size film (35
The original image is created on a mm film) and is enlarged and projected according to the size of a printed matter such as a book. The resolution on the PS plate is not a problem. For this reason, the resolution of the composition having a large reduction / enlargement ratio inevitably decreases, and the object to be printed is limited by the reduced resolution, so that it can be used only for printing the object. is there.

"Object of the Invention" The object of the present invention is therefore to obtain a reduced-enlarged photoengraving system which can be provided at lower cost. It is another object of the present invention to provide a system which can be sufficiently used for printing precise underprinted pages such as halftone photographs, while being an inexpensive system.

"Summary of the Invention" The present invention has been completed based on the idea of using a camera used for reduction photographing of a composition at the time of enlargement photographing. That is, a camera for photographing a composition is to continuously photograph the composition on a roll film, but if the camera's back cover is removed and the photographed filter is photographed, it can be used as a photographing machine. obtain.

That is, the present invention relates to a reduced-enlarged photoengraving system in which a composition is reduced and photographed on a roll film, and the reduced and photographed composition image is enlarged and projected to a PS plate. A light transmitting hole is provided in a portion, and the light transmitting hole can be shielded by a light-shielding back cover to constitute a dual-purpose camera used for both reduced photographing and enlarged projection,
When photographing a composition, cover the translucent hole of this dual-purpose camera with a translucent back cover and shoot on an unphotographed film.At the time of enlargement projection, load the development film that photographed the composition into this dual-purpose camera and attach the shading back cover. It is characterized in that the image under the plate on the developing film is projected and exposed on the PS plate by an illumination lamp arranged behind the light transmitting hole.

The dual-purpose camera has the advantage that distortion of the lens can be canceled. That is, the lens has distortion even though slightly, and the photographed image on the film includes an image distortion due to the distortion. When this photographed image is projected on the PS plate through the same lens as when photographing, the distortion is eliminated, and the same situation as when an image without distortion is projected occurs. That is, since the optical systems at the time of reduction photographing and at the time of enlargement projection are constituted by the same optical system in which the direction of light is reversed, distortion is canceled. In a strict sense, in order to use the same optical system, it is preferable to set the magnification so that the image of the composition to be enlarged and projected has the same size as the actual composition (reduction magnification is 1 / α When, the magnification is α).

In addition, the lens of the dual-purpose camera of the present invention uses a lens whose focal length is fixed, that is, a lens whose image size cannot be changed according to the size of the composition when the distance between the composition and the film is constant. . According to the lens with a fixed focal length, the underprint size and the photographing size can be held in a narrow range for maintaining a constant resolution on the PS plate, and a higher-precision printed matter can be obtained. .

The dual-purpose camera is composed of a substrate for a reduction photographing machine and a
It is practical to make it detachable from the XY board.

The dual-purpose camera can be provided with a pair of parallel flat glasses that hold a film and maintain flatness. In this case, the pair of parallel flat glasses is made of transparent glass, and an illumination lamp for projection is used. Is configured to transmit light.

"Examples of the Invention" The present invention will be described below with reference to illustrated examples. FIG. 1,
FIG. 2 is a conceptual diagram of a reduced / enlarged photoengraving system according to the present invention. FIG. 1 shows a reduced photographing state, and FIG. 2 shows an enlarged projection state.

The dual-purpose camera 10 includes a body 11 and a lens 13 that can be attached to and detached from a detachable flange 12 of the body 11. As shown in FIGS. 3 and 4, the body 11 has a pair of film magazine chambers 15 and 16 on the left and right sides of an aperture 14 for regulating the screen size.
A feed-side film magazine 17 and a take-up film magazine 18 can be inserted into and removed from 5 and 16, respectively. The sending-side film magazine 17 holds the unphotographed roll film F1 or the developed roll film F2, and takes up the winding-side film magazine.
The guide roller 19 exits the film magazine 17 on the sending side.
And the film drawn out through the sprocket 20 is wound and held.

The focal length of the lens 13 is fixed, and if the distance between the film and the object (underlay) is kept constant, the photographing magnification is kept constant.

The film held in the film magazine 17 on the sending side and the film magazine 18 on the winding side can be of any size depending on the purpose.
When photographing at front and rear magnifications, it is desirable to use a 70 mm wide film. According to the 70 mm width, as shown in FIG. 6, even if the perforations P meshing with the sprockets 20 are provided on both sides, the A4 plate can be photographed in the horizontal position, and a stable film feed by perforation can be obtained. .

At the rear of the aperture 14, a pair of parallel flat transparent glasses 21 and 22 that sandwich and hold the unphotographed roll film F1 or the developed roll film F2 and maintain the flatness thereof are located. One of the parallel plane transparent glasses 21 and 22 is a fixed glass 21 and the other is a movable glass 22,
22 is separated from the fixed glass 21 when feeding the film,
During photographing and projection, the film is moved to the fixed glass 21 side and a film is sandwiched between the two.

FIG. 3 and FIG. 4 show examples of the configuration, in which the fixed glass 21 is fixed to the back surface of the aperture 14. The movable glass 22
It is supported by a guide pin 23 implanted in the body 11 so as to be able to contact and separate from the fixed glass 21 and is urged toward the fixed glass 21 by a compression spring 24 so as to move. Cam followers 25 are fixed to the upper and lower ends of the frame of the movable glass 22, and the cam followers 25 are in contact with the eccentric cams 26, respectively. The center of rotation O1 and the center O2 of the peripheral surface of the eccentric cam 26 are eccentric by e. The eccentric cam 26 rotates in synchronization with the film feeding mechanism. When the film is fed, the movable glass 22 is pushed up via the cam follower 25, and when the film is fed by one frame and stopped, the movable glass 22 is compressed. Spring
The state of being pressed toward the fixed glass 21 by 24 is brought about.

A light-transmitting hole 31 is formed in the back cover 30 of the body 11 at a position corresponding to the screen of the film, and a light-shielding back cover 32 is detachable from the light-transmitting hole 31. This shading back cover
32 is attached to the light transmitting hole 31 at the time of reduction photographing and the body 11
The inside of the camera is shielded from light.
Removed from 31.

That is, the dual-purpose camera 10 is set to the first
As shown in the drawing, a light-shielding back cover 32 is attached to a light-transmitting hole 31 of the back cover 30 so as to be in a light-shielding state, and is fixed on a dual-purpose camera support substrate 41 of the reduction photographing machine 40. The support substrate 41 includes an underlaying support table 42.
And above the underlaying support 42,
An illumination lamp 44 for uniformly illuminating the composition 43 placed on the composition support 42 is provided. The support substrate 41 is supported by a support 45.

An unphotographed roll film F1 is loaded in the delivery-side film magazine 17 of the body 11, and the leading end thereof is wound into the take-up film magazine 18 via the guide roller 19 and the sprocket 20. In this state, a required number of images of the composition 43 are photographed in a predetermined order on the unphotographed roll film F1. In this photographing, when the photographing of one block 43 is completed and the film feeding operation is started, the movable glass 22 is raised with respect to the fixed glass 21 in conjunction with this. Then, when the film feeding is completed, the fixed glass 21 approaches the movable glass 22 again and sandwiches the film between the fixed glass 21 and the movable glass 22, thereby maintaining the flatness of the film.

When the photography of all the images 43a of the composition 43 is completed, the unphotographed roll film F1 is developed (FIG. 6). Then, the developed roll film F2 is again used as the dual-purpose camera.
10 is supported in the film magazine 17 on the delivery side, and the leading end is similarly wound on the film magazine 18 on the winding side. The dual-purpose camera 10 which has completed the setting of the developed roll film F2 in this manner, with the light-shielding back cover 32 removed,
As shown in FIG. 2, it is supported on the XY board 51 of the machine 50 with an enlarged projection plane. The machine 50 with an enlarged projection surface has an XY board 51 parallel to the PS plate holding table 52 above the PS board holding table 52.
It can move in the XY direction on the PS plate holder 52 in parallel with this. Although various types of such XY moving devices are well known, in the illustrated example, an X-direction rail 54 is provided on a support pillar 53 erected on a PS plate holding table 52. An X-direction traveling body 55 is supported on the rail 54 so as to be able to travel freely. X
The direction traveling body 55 is a Y-direction guide rail orthogonal to the X direction.
The Y-direction guide rail 56 has an XY board 51
Are movably supported (see also FIG. 5 for the X and Y directions).

An ultra-high pressure mercury lamp 57 as an illumination lamp is provided on the XY substrate 51 on the optical axis of the lens 13, and the light of the ultra-high pressure mercury lamp 57 passes through the light transmitting hole 31 and the movable glass 22.
To the developed roll film F2, and the photographed image 43a (6th
(FIG. 2) is projected onto the PS plate 58 through the lens 13 as a copy image 43b (FIGS. 2 and 5).

Image 43a captured on PS plate 58 by machine 50 with this enlarged projection surface
In the projection exposure, the XY substrate 51 is moved in the XY direction along a predetermined trajectory, and if there are eight planes on one PS plate 58, the underlay images 43b of the eight undercuts 43 are specified as pages. Exposure is performed in the following arrangement. FIG. 5 is a plan view in the case of eight surfaces.

The PS plate 58 on which the exposure of the eight underplate images 43b has been completed is then developed and completed as a printing plate.

The lens 13 is integrally provided with an interference filter 13f that transmits only light of a narrow wavelength including 436 nm (m-line). g-line is the film F1 of the reduction camera 10
The g-line is included in the spectral distribution of the extra-high pressure mercury lamp 57 which is in the photosensitive region of the above and is the illumination light source of the magnifying projection plane attaching device 50. Therefore, the image of the underprint 43 formed on the PS plate 58
43b is an image without chromatic aberration using a narrow wavelength range.

The dual-purpose camera 10 accurately positions the photographed image 43a on the developed roll film F2 at the time of the enlarged projection.
The body 11 may be provided with a positioning marker and detector 28 as shown in FIG. This positioning marker / detector 28 is a non-photographed roll film F1.
Each time the photographed image 43a is photographed, the marker 2 shown in FIG.
9 is to be copied. At the time of enlarged projection, this marker 2
If the position 9 is detected by the positioning marker / detector 28 and the feeding of the developed roll film F2 is stopped, the position of the photographed image 43a can be accurately matched with the aperture 14. Such a positioning marker / detector 28 can be obtained, for example, by placing one end of an optical fiber on a film and selectively arranging a printing light source and a reflective optical sensor at the other end. It is possible.

The present invention does not ask the reduction magnification and the enlargement magnification, but as described above, when the size of the block is up to A4 plate, and the film of 70 mm width is used, the reduction / enlargement magnification is 1/4.
It is fixed at 2x (4x), and a resolution of about 30 lines / mm is obtained on the PS plate 58. This resolving power is a resolving power that can well reproduce a halftone photograph of about 133 lines / inch, and therefore, with the present reduced / enlarged photoengraving system, it is possible to print a wider range of printed matter such as a page including a halftone photograph. .

[Effects of the Invention] As described above, in the present invention, in a reduction / enlargement photoengraving system for enlarging and projecting a reduced copy of a composition, the dual-purpose camera can be used for both reduced imaging and enlarged projection. Therefore, it is not necessary to separately provide an optical system for photographing and projecting in the reduction photographing machine and the magnified projection printing machine, and therefore, an inexpensive photoengraving system can be provided. When a camera is also used, the optical system at the time of reduction photographing and enlargement projection becomes the same optical system including its mechanical configuration, with the optical path reversed, so that the distortion aberration at the time of photographing is canceled at the time of photographing. In addition, by maintaining the resolution on the PS plate by fixing the shooting magnification and enlargement magnification, it is possible to apply the reduced and enlarged photoengraving system even for pages that require higher resolution. .

[Brief description of the drawings]

FIG. 1 is a front view showing a reduced photographing state of a composition by a dual-purpose camera, FIG. 2 is a front view showing a state of the enlarged photographing, and FIG.
The figure is a sectional view of the body of the dual-purpose camera, and FIG. 4 is IV in FIG.
FIG. 5 is a cross-sectional view taken along the line IV, FIG. 5 is a plan view showing an example of the formation of an underprint image on a PS plate in the case of eight faces, and FIG. FIG. 10: Dual-purpose camera, 11: Body, 12: Detachable flange, 13: Lens, 14: Aperture, 15, 16: Magazine chamber, 17: Feed-side film magazine, 18: Winding-side film Magazine, 19: Guide roller, 20: Sprocket, 21: Fixed glass (parallel flat transparent glass), 22
…… Movable glass (parallel plane transparent glass), 24… Compression spring, 25… Cam follower, 26… Eccentric cam, 28… Positioning marker and detector, 29… Marker, 30… Back cover, 31…
… Transparent hole, 32… Shadow back lid, 40 …… Reducer, 41 ……
Support substrate, 42 ... Underlay support, 43 ... Underlay, 43a ... Photographed image, 43b ... Underlay image, 50 ... Magnifier with enlarged projection surface, 51 ... X
Y board, 52… PS plate holder, 57… Ultra high pressure mercury lamp, 58…
… PS version.

Claims (6)

(57) [Claims] 1. A reduced-enlarged photoengraving system in which a composition is reduced on a roll film, and the reduced image of the composition is enlarged and projected to expose a PS plate. A light-transmitting hole is provided in the part, and this light-transmitting hole can be shielded by a light-shielding back cover, and a dual-purpose camera is used for both reduced shooting and enlarged projection. When shooting a composition, the light-transmitting hole of this dual-purpose camera is shielded. Covered with a back cover and photographed on an unphotographed film, at the time of enlargement projection, load the development film that photographed the composition into this dual-purpose camera, remove the light-shielding back cover, and use the illumination lamp arranged behind the light-transmitting hole And a reduction / enlargement photoengraving system characterized by projecting and exposing an image of an underprint on a development film onto a PS plate. 2. The reduced-enlarged photoengraving system according to claim 1, wherein the dual-purpose camera is detachably mounted on a substrate of the reduced photographing machine and an XY substrate of the machine with an enlarged projection surface. Plate making system. 3. A reduced-enlarged photoengraving system according to claim 2, wherein the reduction photographing machine includes an undercarriage support located below the substrate and an undercarriage placed on the undercarriage support. A reduced-enlarged photoengraving system including an illumination light source for illumination. 4. A reduction / enlargement photoengraving system according to claim 2, wherein the enlargement / projection plane-equipped machine comprises a PS plate support table located below the XY substrate and a dual-purpose camera supported on the XY substrate. A reduced-enlarged photoengraving system comprising an illumination light source located on the optical axis and means for moving the XY substrate in the XY direction parallel to the PS plate support. 5. A reduced-enlarged photoengraving system according to any one of claims 1 to 4, wherein the dual-purpose camera is provided with a pair of parallel flat transparent glasses holding a film to maintain flatness. A photoengraving system with reduced size. 6. A reduction / enlargement photoengraving system according to any one of claims 1 to 5, wherein the lens of the dual-purpose camera is a lens having a fixed focal length.