JPS62244031A - Slit exposing device - Google Patents

Abstract

PURPOSE:To uniformly execute an exposure extending over the whole surface of an original surface, and to obtain a photoengraving and a copy having good image quality, by running an original which is placed on an original platen, by covering it with an overlay sheet, and also, bringing the original surface to a slit exposure by a light source. CONSTITUTION:As a slit exposing device 8 moves, an overlay sheet 152 which is wound round to a winding-in roller 84 is rewound against a torsion spring, and covers an original 2 on an original supporting base 151, extending over the whole surface, in a state that it is spread out. On the other hand, together with it, a suction device 153 is also started and absorbs the inside of the original supporting base 151, the overlay sheet 152 is welded by pressure so as to adhere tightly onto the original supporting base 151, and the original 2 which is inserted and attached between them is fixed onto the original supporting base 151. The original is exposed by a light source 81 and a reflecting plate 82 and its reflected light is projected upward from a slit0shaped opening part 83, and it is exposed by a slit width portion each onto a photosensitive material 5 which is held by said photographing part, through a mirror 3 and a lens 4 of an electrophotographic photoengraving machine of a camera type.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. Technical Field of the Invention This invention relates to a slit exposure device having a document holding mechanism used in camera-type "Full static exposure JJ type" electrophotographic engraving machines, electronic copying machines, etc. .

(Technical aspects of the invention and its problems) Figure 4 is a cross-sectional structural diagram showing an outline of a conventionally used camera-type electrophotographic engraving machine as an example of the "full-surface static exposure method". .

In the same figure, l creates a printing plate (hereinafter referred to as "plate making")
Holds the manuscript 2 to be written (called "manuscript"). Photographing light is irradiated from above in the figure by a light source (not shown) onto the entire surface of the document 2 held on the document table 1 with the document surface facing upward in the figure.

This photosensitive material is reflected by the am surface, reflected by the mirror 3 as shown by the dashed line in the figure, and is imaged by the lens 4 on the photosensitive material 5 held in the engraving section (full-surface static exposure). 5 is transferred in advance from the paper feed section 6 to one stage of conveyance (not shown) by hlii! It is supplied to the photographing section, and after photographing, it is conveyed to the processing section 7 by the above-mentioned conveying means as shown by the dotted line in the figure, where processing such as development and fixing is performed. A printing plate is adapted to be released.

This camera-type electrophotographic engraving machine is a console-type electrophotographic engraving machine that takes pictures with the original side of the original to be made facing toward the device (unlike a plate-making machine, the original side of the original to be made into a plate is taken face down). Since the photo is taken facing toward the person (facing up),
It has the advantage of being able to detect curved aZt manuscripts, errors in E, etc. on the spot, and to prevent simple plate-making mistakes. In the photoXglI printing machine, since the photographing light statically exposes the entire surface of the document, it is difficult to uniformly expose the entire surface of the document due to the characteristics of the light source 1 reflecting mirror, lens, etc.; Both edges in the width direction and length direction) are underexposed (so-called °°) compared to the center.
There is a problem that tVt with good image quality cannot be obtained due to excessive shading (shading).

The 21st review (A), (B) and the 31st review (A), (B) are
The cross-sectional structure of the original platen 1 is shown in Figure 2 (
A) is a sectional view showing a schematic structure of a spring-type document table 100. In FIG. 2(A), the original support 110□ on which the original 2 to be printed is placed is attached to the metal plate 1'13. i
The fixed sponge 112.

PE (polyethylene terephthalate) sheet.

Lumirror or nonwoven 7M7111 is laid to cover it. In addition, the sheet metal 113 of this original support base 0 is fixed to the printing machine main body 120 by a plurality of springs 114. Then, the original 2 placed on the original support stand 11G, t is moved from its upper surface ([laminated surface]) by a glass plate lot, which is a transparent plate member, provided at a rotation r1 centering on the hinge part 102. It is adapted to be pressed against the abutment 110.

The glass plate 101 is moved to a predetermined position, and the original 2 is held in close contact with the glass plate 101 by the pressing force of the sponge 112 and spring 114 of the document support 110. Therefore, this glass plate 101 has a handle 103 attached to the hinge for opening and closing the glass plate 1.01 and for fixing it to the main body by a fixing means (not shown) when pressing the I It is provided on the opposite side of the section 102. As shown in FIG. 2(A), such a spring-type document table 100 needs to hold one sheet of flat document 2 due to the pressing force of the sponge 112 and spring 114 of the document support table 11G. Although it is possible to create a printing plate of good quality by being appropriately pressed against the glass plate 101, the 211a (B
), in the case of a pasted original 20 with another original 22 pasted on top of the original 21, the pressing force of the sponge 112 of the original support 110 and the spring 4 alone will not allow this pasted original 20 to be pasted above the original 21. The originals 22 cannot be pressed against the glass plate 101 sufficiently uniformly.
A gap 23 occurs due to the difference in level between 1 and 1, and if the plate is made in this state, a shadow (black outline) will appear on the printing plate created in 1 at the gap 23 marked by 1. Shadows are more likely to occur as the thickness of the original 21, 22 increases.1 Not only does it take an extra effort to erase the contour lines caused by these shadows using an erasing liquid from the printing plate that has been created, but also This causes deterioration in the image quality of printed matter made using In addition, in the spring-type document holder 10G, if the pushing force of the sponge 112 and spring 114 is biased, the document cannot be evenly pressed against the glass plate 101, especially when the document is warped or wrinkled. If, due to the above-mentioned insufficient pressing force, the original is not evenly pressed against the glass plate 101, and the printed printing plate produced is different from the original and has a distorted pattern, etc.! There is 1 point.

On the other hand, No. 31!4 (A) is a sectional view showing the schematic structure of the vacuum type document table 150. In FIG. 3(A),
The box-shaped document support 151 has holes 15 of m number uniformly formed on its top surface.
1A is opened, and the opening provided on the bottom surface is for suction (not shown)! Connected to position A. This box-shaped document support 151 has, for example, transparent PET on its sides.
One end of an overlay sheet 152 made of a sheet or the like is fixed, and the overlay sheet 152 covers the entire upper surface of the document support 151. Therefore, place the original 2 to be made into a plate on the original support stand 151, and place the overlay sheet 1 on top of it.
52, and further the document support 1 is covered by the suction means.
When the inside of 51 is aspirated.

Due to this suction force, the overlay sheet 152 is pressed into close contact with the L original support 151 through the hole 151A and the original 2, and the original 2 sandwiched between them is fixed on the original support 151. be able to. In the case of this vacuum type document table 150, the pasted document 2 as described above is
Even if the overlay sheet 152 is 0, as shown in FIG.
Since the originals 21 and 22 are in close contact with each other under pressure, there are 11 J11 printing plates that are of high quality and are less likely to cause shadows between the original documents 21 and 22. Furthermore, even if the document L document 2 has warps or wrinkles, the overlay sheet 152 sucked out will smooth out the warpages or wrinkles and press it against the document support, resulting in a high-quality printing plate. It has the advantage of being However, this vacuum type IfX 150
In this case, since the document is photographed from the side of the overlay sheet 152 during plate making, the condition of the overlay sheet 152 directly affects the quality of the printing plate. Therefore, when manually covering the document 2 with the overlay sheet 152, if the overlay sheet 152 is sucked with wrinkles 58, the image quality of the created mark sg1 is degraded due to the wrinkles. The problem with 1flT is that it takes a lot of time and effort to smooth out the wrinkles. Also, this overlay sheet 15
2 is prone to scratches and dust, and these scratches and dust 1 reduce the image quality of the printing plate to be created.
There is a problem in that it takes a lot of time and effort to set up, store, etc.

(Object of the invention) This invention was made under the above circumstances,
The purpose of this invention is to enable uniform exposure over the entire surface of a document, to prevent shadows between the documents even in pasted documents, etc., and to perform plate making and copying with good speed and accuracy.
An object of the present invention is to provide a slit exposure device with excellent operability.

(Summary of the Invention) The present invention comprises: a document table having a plurality of ventilation holes and on which a document is placed; a transparent overlay sheet whose rear end is fixed to the rear end of the document table; A housing with a door opening that travels back and forth on a table, and a winding which is provided at the front inside of this housing, is provided with an elastic rotation force that turns the L portion rearward, and has the front end of the overlay sheet fixed thereto. a light source that is provided behind the take-up roller and exposes the document; and a light source that is provided on the top surface of the L housing and projects reflected light that has been exposed from the light source and reflected on the L assigned surface to the outside. In the slit exposure device, the slit exposure device includes a slit-shaped opening for removing the original document and a suction means provided on the lower surface of the document table to suck the document and the overlay sheet.
The original document placed in A is covered with an overlay sheet marked J2 while traveling, and the original surface area marked I is exposed to slit light by the above-mentioned light source.

(Embodiment of the Invention) FIGS. 1(A) and 1(B) are perspective views showing the outline of a sleeve l-exposure device 8 of the present invention applied to an L camera type electrophotographic printing machine as an embodiment thereof. 3(B) and FIG. 4, the same reference numerals are given to the structural members shown in FIG. 3 (^), (B), and FIG.

In FIGS. 1(A) and (B), reference numeral 150 is a vacuum-type document table on which 41 originals to be plate-made are placed, and the box-shaped document support 151 is painted, for example, white, and is evenly distributed on its upper surface. A plurality of holes 151A are drilled, and on the F side,
The serving opening may be a suction device 1 consisting of a fan 1, for example.
53. Guide rails 15 A and 157B on which a slit fog light device 8 (to be described later) reciprocates in the direction of A-B in the figure are disposed at both ends of the document support 151 in the width direction. One end shown B
A motor 154 for reciprocating the L slit exposure device 18 in the direction A-B in the drawing is disposed at a predetermined position l (end) in the direction, and a motor 154 is provided at a predetermined position 21 (end) in the direction A in the drawing. A guide roller 155 is provided, and a timing belt 158 is wound between the shaft of the motor 154 and the guide row 5155. Then, at a predetermined position near the L motor 154 and the guide roller 55, a
A proximity sensor 158 is provided for optically detecting the exposure device, for example. Also, this manuscript support! 51 has, for example, a transparent "PI" on one side (end ff1) in the direction B in the drawing.
One end of an overlay sheet 152 made of ET sheet or the like is fixed.

- Force 8 is a slit fog light device W18 of the present invention which is provided on the vacuum type document table 150 so as to be able to reciprocate in the direction of A-B in the figure, and its lower surface (E (solid surface side) opening The housing 80 is placed at a predetermined position in the -F direction from the center toward the direction B in the drawing.
A light source 81, which is a lamp or the like, has a length equal to the width of the light source 81 and can expose the entire area in the width direction; Manuscript 2
A reflecting plate 82 is provided to reflect the light. This light source 8
1 is exposed in the form of a slit along the width direction of the L:2 original area surface, so the exposed area in the running direction (the short width direction of the slit) is very narrow, so that the light can be misted uniformly. The entire area in the direction is also a narrow 1ull (slit),
By inserting a filter with a characteristic that matches the light intensity at the center with the light intensity at both ends, the entire surface can be exposed completely uniformly.

The reflected light reflected from the original surface 2 is projected upward in the figure onto the light s81 and the E side of the reflecting plate 821111, and the camera-type electrophotographic engraving machine Mirror 3. A slit-shaped opening 83 long in the width direction is provided for exposing the photosensitive material 5 held in the photographing section E through the lens 4. Furthermore, a winding roller 84 forming one width direction is provided at a predetermined position in the direction A in the figure on the inside upper side of the housing 8G, and presser rollers 85 are provided at both ends of the lower surface (in the A-B direction shown in IffI). and 86 are provided. The above-mentioned winding roller 84
An elastic rotational force is applied to the overlay sheet 152 in the direction C in the figure by, for example, a torsion spring, as will be described later, and the other end of the overlay sheet 152 is wound Ii. Further, guide wheels 87 are provided at both outer ends of the housing 80 in the width direction, which are pivotally attached to the housing 80 and run back and forth on the guide rails 157A and 1571 while keeping the RJ 1 body 80 at a predetermined distance from the document surface. At one end of the housing 80 in the width direction, a means 8θ for engaging the housing 80 with the timing bell 1511 is provided.

The exposure operation of the slit exposure apparatus a configured in this way will be explained below. At the start of plate making, the above slip)! light! It is assumed that the position 1 is placed at a predetermined position at the end in the direction B in the drawing. Therefore, the manuscript table 150J
After placing the original 2 at a predetermined position in Z, when the slit exposure device 8 is started, the motor 154 is rotated and the timing bell H5g is set to tI! J movement, and accordingly, the slit exposure device 8 is caused to travel in the direction A in the figure through the L2 engagement first stage 88 on the guide rails 157A and 15781:. Therefore, as the slit exposure device 218 moves, one end of the overlay sheet 152 wound around the winding roller 84 is fixed to the side edge of the document support 151 in the direction B in the figure. Holder roller 8
5 and 8B, the document support 15 is unwound against the torsion spring and is stretched.
! At the same time, the device 153 is also activated and sucks the inside of the document 6tst, and this suction force causes the hole 1 in L to be covered completely.
51^ and the above overlay via manuscript 2) 1
52 is pressed against the document support 151-, and the document 2 sandwiched therebetween is pressed against the document support 151-.
It can be constant at 1-L. Therefore, the document surface 2 pressed by the overlay sheet 152 is exposed to light by the L light distribution source 81 and the reflection plate 82, and the reflected light is projected upward in the figure from the slit-shaped opening 83. Mirror of electrophotographic engraving machine 3. The photosensitive material 5 held in the photographing section is exposed through the lens 4 by the width of the slit. At this time, the exposure for the width of the slit is 1! The shading is performed uniformly over the entire width of the X document 2, and an image with good quality without problems such as L shading can be obtained.

As the slit exposure device 8 moves in the direction A in the figure, the originals 2 placed on the original platen 150L are sequentially covered with the overlay sheet 152 that is rewound, and are suctioned by the suction device 153. While being brought into pressure contact with the exposure device 18, the exposure device 18 is exposed by the width of the slit, and the above-described operation is continued until the exposure device 18 is detected by the proximity sensor 158 at the end in the entrance direction as shown in the figure. When the entire surface of the document 2 has been photographed, the motor 154. , h, after which the light distribution source 81 and the suction device 153 are stopped.

When the L motor 154 is rotated in the reverse direction to return the slit exposure device 8 to the direction B in the figure, since the suction device 2i153 is stopped, the overlay sheet 152 that was pressed against the original 2 is easily separated. , 11. Since the take-up roller 84 is rotated in the take-up direction by the torsion spring, the overlay sheet 152 is automatically and completely wound up and stored on the take-up roller 84 without sagging in the stretched state. 1, and the proximity sensor 15 at the end in the direction B shown in the figure.
The above-mentioned operation is continued until the exposure mold 218 is detected in step 158, and the slit exposure mold 218 that has the overlay sheet 152 rolled up and accommodated is placed at the initial predetermined position, and the original 2 that has undergone plate making is It becomes possible to attach and detach the document from the document table 151.

Although the original It42 was not specifically described in the above-mentioned embodiment, even in the case of a pasted original or a wrinkled original as described above, the overlay sheet 152 prevents the shadow caused by the difference in level between the pasted originals. Blurring caused by wrinkles and wrinkles are eliminated, and printing plates with good image quality can be obtained.

(Modified Example of the Invention) In the above-described embodiment, an example was shown in which the slit exposure device of the present invention is applied to a camera-type electrophotographic engraving machine. Needless to say, it can also be applied to

(5F, Bright Effect) As described above, the slit exposure device of the present invention uses the slit exposure method and can uniformly expose the entire surface of the document, and also has a vacuum type document table and an overlay sheet. As a result, even in pasted originals, there is no shadow between the originals, and plate making and copying with good image quality can be performed. In addition, this overlay sheet is automatically rewound and stretched to cover the manuscript, so there are no wrinkles, and a torsion spring closes the cover after plate making is complete. e
Since the overlay sheet is rolled up and stored, it is not only easy to operate, but also prevents scratches and dust from adhering to the overlay sheet.

This will improve durability.

[Brief explanation of drawings]

FIGS. 1(A) and (B) are a perspective view and a sectional structural view showing a -χ embodiment of the slit exposure apparatus of the present invention, and FIG. 2(^)
and (B) are cross-sectional structural diagrams schematically showing a conventionally used spring-type document table, and FIGS. 3 (A) and (B) are cross-sectional structural diagrams schematically showing a conventionally used vacuum-type document table. 4 are cross-sectional structural diagrams schematically showing a camera-type electrophotographic engraving machine to which the present invention can be applied. 1.100,150...Original table, 2.20,21.
22...Manuscript. 3...Mirror, 4...Lens, 5...Photosensitive material,
6... Paper feed section, 7... Processing section, 8... Slit exposure device, 23... Gap, 8G... Housing, 81.
...Light source, 82...1 Reflector, 83... Opening, 8
4... Take-up roller, 85.8111... Presser roller, 87... Guide wheel, 88... Engagement r first stage, 1
01...Glass plate 2102...Hinge part, 103...
・・Handle f=, 110, 151 ・・Document stand, 112
...Sponge, 114...Spring, 151A
... Hole, 152 ... Overlay sheet, 153 ...
・Suction device fi, 154...Motor, 155...Guide roller, 15B...Timing belt, 157A
, 157B...Guide rail, 15g...Proximity sensor. Applicant's agent: Yu Yasugata Three-way diagram 2

Claims (1)

[Claims] A document table having a plurality of ventilation holes and on which a document is placed, a transparent overlay sheet whose rear end is fixed to the rear end of the document table, and a casing with an opening at the bottom that travels back and forth on the document table. and,
A take-up roller is provided at the front inside of the housing, is provided with an elastic rotational force to turn the upper part rearward, and has a front end of the overlay sheet fixed thereto; a slit-shaped opening provided on the top surface of the housing and projecting reflected light exposed from the light source and reflected on the document surface to the outside; provided on the bottom surface of the document table; A suction means for suctioning the original and the overlay sheet, the original placed on the original table is traveled while being covered with the overlay sheet, and the surface of the original is exposed to slit light by the light source. A slit exposure device featuring: