JP2004144938A - Sheet material fixing apparatus and drum type exposure apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet material fixing apparatus which reliefs wrinkles of a sheet material and mounts the sheet material in a right position on a drum, and to provide a drum type exposure apparatus. <P>SOLUTION: The apparatus is equipped with chucks each having first and second portions interposing a fulcrum arranged in the direction of the rotation axis of a drum and mounted on the drum, and with a chuck pushing part having projections with on-to-one correspondence to the chucks. The projection nearer to a specified chuck pushes the corresponding chuck at a point on the first portion nearer to the fulcrum, while the projection farther from the specified chuck pushes the chuck at a point on the first portion farther from the fulcrum so that the moving rate of the second portion is increased to fast open or shut the chuck. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet material fixing device that fixes a sheet material to a drum, and a drum type exposure device that exposes a sheet-like photosensitive material wound around a rotating drum.
[0002]
[Prior art]
Conventionally, in the field of printing, a sheet-form original plate, which is called a PS plate (Presensitized Plate), in which a hydrophilic layer and a photosensitive layer are sequentially stacked on an aluminum thin plate, is wound around a drum, and based on an original image while rotating the drum 2. Description of the Related Art Drum-type exposure apparatuses that expose an original by irradiating the original with a light beam are widely used. In such a drum type exposure apparatus, a mechanism for fixing the original plate in close contact with the drum in order to prevent the original plate from shifting when the drum is rotating or from being lifted between the drum and the original plate. Is required. Normally, a plurality of chucks are mounted on the drum in parallel with the rotation axis, and these chucks hold the original plate on the drum by holding the end of the original plate. The drum type exposure apparatus is also provided with a chuck opening / closing means for opening and closing these chucks, and the original plate fixing device that combines the chuck and the chuck opening / closing means can automatically fix the original plate without bothering human hands. (For example, refer to Patent Document 1).
[0003]
By the way, as one of the above-mentioned original plate fixing devices, a plurality of lever-like chucks mounted side by side on a drum and opened and closed by opening and closing, and chuck opening / closing means having a plurality of protrusions corresponding to each chuck are provided. An original plate fixing device is known. In this original plate fixing device, the chuck opening / closing means moves toward the drum, and along with the movement, each projection pushes one side of the corresponding chuck and opens a gap to sandwich the original plate between the other side and the drum. On the contrary, the chuck opening / closing means closes the gap between each chuck and the drum by moving away from the drum. Here, when one original plate is sandwiched between a plurality of chucks, the original plate may be wrinkled depending on the order in which the chucks are closed. If exposed as it is, there is a problem that the light beam may be out of focus or the image may be distorted. is there. Usually, originals for each color of C (cyan), M (magenta), Y (yellow), and K (black) are exposed, and each exposed original is developed by a developing machine. A printing plate is produced in which the photosensitive layer remains only in the irradiated portion and the hydrophilic layer is exposed in the other portions. Further, these printing plates are mounted on a printing press, and each color ink is applied only to the photosensitive layer of each printing plate, and the printing image is printed on the paper so that the printing plate images are superposed one by one. For this reason, if a focus deviation or image distortion occurs in a certain color original during exposure, the print images of each color constituting the print image do not overlap and the print image becomes a blurred image. Therefore, in order to prevent this, the length of the protrusion provided on the chuck opening / closing means is shortened in order from one end so that the short protrusion first moves away from the chuck first when moving the protrusion in the direction of closing the chuck at the same time. Thus, the chuck is closed sequentially from one side.
[0004]
[Patent Document 1]
JP 2002-46890 A (5th page, 6th page, FIG. 1)
[0005]
[Problems to be solved by the invention]
However, according to the above method, the stroke for pushing down the chuck differs greatly between the shortest protrusion and the longest protrusion, and the chuck corresponding to the short protrusion may not be completely opened. At this time, the chuck that cannot be fully opened becomes a resistance when the original is mounted, and the original is mounted obliquely, and there is a fear that the image is shifted during exposure.
[0006]
In addition, as described above, the problem that the sheet material is wrinkled or the sheet material is not properly mounted on the drum is not limited to the drum type exposure apparatus, and a sheet material such as a thin plate is fixed to the drum provided with the chuck. This is a problem common to all devices having a fixing device.
[0007]
SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a sheet material fixing device and a drum type exposure apparatus that open a wrinkle of a sheet material and mount the sheet material at a correct position on a drum.
[0008]
[Means for Solving the Problems]
The sheet material fixing device of the present invention has a first and a second part, each of which is mounted on a drum rotating around a circumferential surface of the sheet material, arranged side by side in the direction of the rotation axis of the drum, each sandwiching a fulcrum. A chuck that sandwiches a sheet material between the drum and the second portion;
The plurality of chucks have a plurality of protrusions protruding toward the chuck in a one-to-one correspondence, and the first portion of the corresponding chuck is pushed and separated at the tip of the protrusion between the second portion and the drum. Of the plurality of chucks that fix the sheet material, the closer the chuck to the first chuck, the closer to the fulcrum on the first part, the farther from the predetermined chuck, the higher the chuck on the first part. And a chuck pushing portion for pushing away a point far from the fulcrum.
[0009]
Even if the first part is pushed and released by the same stroke amount, the rate at which the second part is moved differs depending on the pushing position, and the second part increases as the position closer to the fulcrum of the first part is pushed away. The rate at which is moved increases.
[0010]
The chuck pressing / separating portion in the sheet material fixing device of the present invention pushes a point closer to the fulcrum on the first portion of the corresponding chuck as the protrusion closer to the predetermined chuck, so that all the chucks are open. When the chuck pressing / separating portion is moved in the direction away from the drum, the chuck is separated from the chuck in order from the protrusion at a position close to the predetermined chuck. Therefore, according to the sheet material fixing device of the present invention, for example, the chuck can be closed sequentially from one end chuck, and the sheet material can be gripped by the chuck while wrinkles are released.
[0011]
In the sheet material fixing device of the present invention, it is preferable that the chuck pressing / separating portion has a protrusion whose length is shorter as the corresponding chuck is closer to a predetermined chuck.
[0012]
The protrusion that is closest to the predetermined chuck and the protrusion that is farthest from the predetermined chuck are greatly different in the ratio of the second part being moved even if the first part is pushed and released by the same stroke amount. Since the gap formed between the two is not constant, it may be difficult to attach the sheet material. The protrusion closer to the predetermined chuck has a shorter length, and the protrusion farther away has a longer length, and the protrusion farther away increases the amount of stroke that pushes the first part of the chuck. A gap formed between the chuck and the drum corresponding to the protrusion at a distant position can be sufficiently opened as well as a gap between the other chuck and the drum.
[0013]
Furthermore, in the sheet material fixing device of the present invention, the first portion may include a first portion whose tip is inclined in a direction away from the peripheral surface of the drum when the protrusion is separated.
[0014]
As described above, the stroke amount of the first part pushed away from the protrusion by the inclination of the first part is not adjusted by changing the length of the protrusion and adjusting the stroke for pushing away the first part of the chuck. It may be adjusted to adjust a gap formed between the chuck and the drum.
[0015]
The drum-type exposure apparatus of the present invention rotates a drum around which a sheet-like photosensitive material is wound, and also scans the photosensitive material on the drum in the direction of the rotation axis of the drum with light to expose the photosensitive material. In the device
A plurality of chucks mounted on the drum in the direction of the rotation axis of the drum, each having a first and a second part sandwiching a fulcrum, and sandwiching a photosensitive material between the drum and the second part;
The plurality of chucks have a plurality of protrusions protruding toward the chuck in a one-to-one correspondence, and the first portion of the corresponding chuck is pushed and separated at the tip of the protrusion between the second portion and the drum. Of the plurality of chucks for fixing the photosensitive material, the closer to the chuck, the closer to the fulcrum on the first part, the closer to the first part, and the closer to the first part, the closer to the first part. And a chuck pushing portion for pushing away a point far from the fulcrum.
[0016]
According to the drum type exposure apparatus of the present invention, the sheet material can be mounted at an accurate position by sufficiently opening a gap formed between the chuck and the drum while controlling the order of opening and closing the chuck. It is possible to prevent out-of-focus and distortion of the image.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described.
[0018]
When printing a print image, first, image data for each color representing the CMYK four-color plate images constituting the print image is generated at a workstation or the like. These image data are input to the image exposure apparatus. In the image exposure apparatus, a light beam based on each input image data is irradiated on an original plate in which a hydrophilic layer and a photosensitive layer are sequentially laminated on a thin plate such as aluminum, and the original plate for each color of CMYK is exposed. . Each exposed original plate is mounted on a developing device and developed, and the photosensitive layer remains only in the portion irradiated with the light beam of each original plate (the portion corresponding to each color plate image), and the other portion has a photosensitive layer. A printing plate is produced that is removed to expose the hydrophilic layer. Further, these printing plates are mounted on a printing machine, and the hydrophilic layer of the printing plate repels oil-based ink so that the ink is applied only to the photosensitive layer of the printing plate, so that each color plate image is superimposed one by one. A printed image is formed by printing. Hereinafter, the image exposure apparatus will be described.
[0019]
FIG. 1 is a schematic block diagram showing an image exposure apparatus to which an embodiment of the present invention is applied.
[0020]
The image exposure apparatus 10 includes a drum 100, a front end chuck 110, a feed / discharge plate unit 200, a rear end chuck pressing / separating unit 300, a rear end chuck 320, a front end chuck pressing / separating unit 400, a roller 500, and an exposure unit 600. Yes.
[0021]
The features of the image exposure apparatus 10 as the drum type exposure apparatus of the present invention are the tip chuck pressing / separating portion 400 and the tip chuck 110. First, the overall configuration of the image exposure apparatus 10 will be described.
[0022]
The drum 100 is a drum that rotates by winding an original plate around a peripheral surface. The drum 100 is provided with a plurality of grooves extending in the rotating direction of the drum 100 along the peripheral surface of the drum 100 in order to attach a rear end chuck 320 described later. The drum 100 corresponds to an example of a drum according to the present invention.
[0023]
A plurality of front end chucks 110 are mounted side by side in the direction of the rotation axis on the drum 100, and hold the front end of the original plate to fix the original plate to the drum 100. In the present embodiment, when the tip chuck 110 is pushed by the tip chuck pushing portion 400, the chuck opens to form a gap for fixing the original plate with the drum 100, and when the tip chuck pushing portion 400 is separated, the chuck is opened. Closes and closes the gap with the drum 100. The tip chuck 110 corresponds to an example of a chuck in the sheet material fixing device and the drum type exposure apparatus of the present invention.
[0024]
The supply / discharge plate unit 200 includes a plate supply guide 220 for supplying the original plate to the drum 100 and a plate discharge guide 210 for discharging the original plate from the drum 100.
[0025]
The tip chuck pushing / separating portion 400 includes a plurality of protrusions 410 arranged on the tip chuck 110 in a one-to-one correspondence. When the drum 100 rotates and the tip chuck 110 comes directly below the tip chuck pushing portion 400, the tip chuck pushing portion 400 moves toward the tip chuck 110, and the protrusion 410 pushes the corresponding tip chuck 110 to hold the chuck. open. When the original plate is supplied from the plate supply guide 220 and the front end of the original plate is mounted in the gap between the front end chuck 110 and the drum 100, the front end chuck pressing / separating portion 400 moves to the original position, and the protrusion 410 is moved to the front end. The chuck 110 is released and the chuck is closed. The protrusion 410 corresponds to an example of the protrusion in the sheet material fixing apparatus and the drum type exposure apparatus of the present invention, and the tip chuck pressing / separating unit 400 corresponds to an example of the chuck pressing part in the sheet material fixing apparatus and the drum type exposure apparatus of the present invention. .
[0026]
The rear end chuck pressing / separating part 300 has a protrusion 310 and basically has the same structure as the front end chuck pressing / separating part 400. The rear end chuck 320 has basically the same structure as that of the front end chuck 110 except that the rear end chuck 320 is attached in a direction opposite to that of the front end chuck 110. Further, in order to deal with a plurality of sizes of originals, the rear end chuck 320 for gripping the rear end of the original is not fixed to the drum 100 in advance, but after the size of the original is recognized by a sensor (not shown), The drum 100 is attached at a position corresponding to the rear end of the original. The rear end chuck 320 is not always fixed to the drum 100, but is mounted on the drum 100 when the drum 100 is rotated and the original is exposed.
[0027]
The roller 500 is a roller for moving in the direction of the drum 100 when the original is wound around the drum 100 and bringing the original into close contact with the drum 100.
[0028]
The exposure unit 600 irradiates the drum 100 while moving a light beam based on image data input from a workstation (not shown) or the like in the direction of the rotation axis of the drum 100, and exposes the original wound around the drum 100. .
[0029]
The image exposure apparatus 10 is basically configured as described above. Next, a series of procedures for attaching the original plate to the image exposure apparatus 10 and exposing the original plate will be described.
[0030]
When the drum 100 is rotated and the tip chuck 110 is moved directly below the tip chuck pushing portion 400, the tip chuck pushing portion 400 is driven toward the tip chuck 110, and each protrusion 410 pushes the corresponding tip chuck 110. The chuck opens.
[0031]
An original plate accommodated in a cassette (not shown) is supplied to the drum 100 by a plate supply guide 220 of the supply / discharge plate unit 200, and the front end of the original plate is mounted in a gap formed between the tip chuck 110 and the drum 100. The When the front end of the original plate is mounted at the correct position, the front end chuck pushing / separating portion 400 moves to the original position, and the protrusion 410 moves away from the front end chuck 110 along with the movement. The gap of closes.
[0032]
When the front end of the original is gripped by the front end chuck 110, the drum 100 rotates in the direction of arrow a, and the roller 500 sandwiches the original and the drum 100 to release wrinkles of the original. When the rear end of the original is detected by a sensor (not shown), the drum 100 rotates and the rear end of the original is moved to a position corresponding to the rear end chuck pushing / separating unit 300. A rear end chuck 320 is provided at the tip of the rear end chuck pressing part 300, and when the rear end chuck pressing part 300 moves to press the rear end of the original, the rear end chuck 320 is provided on the drum 100. It is attached to the drum 100 so as to be pushed into the groove. Further, the rear end chuck pressing part 300 pushes the rear end chuck 320 by the same operation as the front end chuck pressing part 400 to open the chuck, and the rear end chuck 320 grips the rear end of the original as in the front end chuck 110. To do. When the rear end of the original is gripped by the rear end chuck 320, the roller 500 moves to the original position, and the drum 100 rotates at high speed in the direction of arrow a.
[0033]
As the drum 100 rotates at a high speed, the exposure unit 600 irradiates the drum 100 while moving the light beam in the direction of the rotation axis to expose the original.
[0034]
When the exposure is completed, the drum 100 rotates so that the rear end of the original plate is directly below the rear end chuck pressing / separating unit 300.
[0035]
The rear end chuck pushing / separating unit 300 opens the rear end chuck 320 to release the rear end of the original, and further removes the rear end chuck 320 from the drum 100.
[0036]
When the rear end chuck 320 is removed, the drum 100 rotates in the direction of the arrow b so that the front end chuck 110 is located directly below the front end chuck pressing / separating portion 400. The tip chuck pushing / separating unit 400 opens the tip chuck 110 and opens the tip of the original. At this time, the rear end of the original plate is on the discharge plate guide 210, and the discharge plate guide 210 carries the original plate toward a discharge port (not shown), and the exposure process is completed.
[0037]
Next, the tip chuck pushing / separating portion 400 and the tip chuck 110, which are features of the drum type exposure apparatus of the present invention, will be described in detail.
[0038]
FIG. 2 is a front view of the image exposure apparatus 10 shown in FIG. In the following, for convenience of explanation, what is shown at the left end in FIG. 2 is expressed as the leftmost in other figures, and what is shown at the right end in FIG. 2 is expressed as the rightmost in other figures. I will explain.
[0039]
As shown in FIG. 2, the tip chuck 110 is mounted on the drum 100 side by side in the rotation axis direction. Further, the protrusions 410 provided on the tip chuck pressing / separating portion 400 are arranged on the tip chuck 110 so as to correspond to the one-to-one correspondence. As for the length of the protrusion 410, the length of the leftmost protrusion 410b corresponding to the leftmost tip chuck 110b is the longest, and the length of the protrusion 410 becomes shorter as it approaches the rightmost tip chuck 110a. The length of the rightmost protrusion 410a is the shortest. The rightmost tip chuck 110a corresponds to an example of a predetermined chuck according to the present invention.
[0040]
FIG. 3 is a perspective view of the drum 100 and the tip chuck pushing / separating portion 400 as viewed from the rightmost tip chuck 110a side when the tip chuck 110 is pushed by the tip chuck pushing / separating portion 400 to open the chuck.
[0041]
The front end chuck 110 includes a pushing / separating portion 112 and a sheet gripping portion 113 sandwiching the fulcrum 110. As shown in FIG. 3, the protrusion 410 of the tip chuck pushing / separating portion 400 pushes a point closer to the fulcrum 111 of the tip chuck 110 as the protrusion 410 closer to the rightmost tip chuck 110 a. The fulcrum 111 of the tip chuck 110 is an example of a fulcrum according to the present invention. Similarly, the pushing / separating portion 112 is an example of the first portion according to the present invention, and the sheet gripping portion 113 is the second portion according to the present invention. It corresponds to an example.
[0042]
FIG. 4 is a top view of the rightmost tip chuck 110a and the leftmost tip chuck 110b, and a simplified side view of the drum 100 and the tip chuck pushing / separating portion 400 viewed from the side.
[0043]
The top view shows that the rightmost push point 114a when the rightmost tip chuck 110a is pushed by the rightmost protrusion 410a is more than the leftmost pushpoint 114b when the leftmost tip chuck 110b is pushed by the leftmost protrusion 410b. It shows that it is close to the fulcrum 111. Therefore, when the tip chuck 110 is pushed by the protrusion 410 by the same stroke amount, the leftmost tip chuck 110b pushed by the leftmost pushpoint 114b far from the fulcrum 111 is more sheet-seat 113 than the rightmost tip chuck 110a. The rate at which is moved is small.
[0044]
In the simplified side view, the rightmost protrusions 110a and the leftmost protrusions 410b push the respective separation portions 112 of the rightmost tip chuck 110a and the leftmost tip chuck 110b, and the sheet gripping portions 113 are moved by the same opening amount. The tip chuck pushing / separating portion 400 and the tip chuck 110 are shown. Further, the front end chuck 110 is an elastic member 114 that urges the pushing / separating portion 112 in a direction opposite to the direction pushed by the protrusion 410 below the pushing / separating portion 112 in order for the sheet gripping portion 113 to hold the original. It has. Thus, the leftmost protrusion 410b that pushes the leftmost pressing point 114b far from the fulcrum 111 is longer than the rightmost protrusion 410a, and even if the leftmost protrusion 410b has a small rate of moving the sheet gripping portion 113, the original plate can be used. Sufficient clearance can be made to pinch. In this state, the tip chuck pushing / separating portion 400 is moved upward to close the chuck of the tip chuck 110.
[0045]
FIG. 5 is a simplified side view of the drum 100 and the tip chuck pressing / separating portion 400 as viewed from the side when the tip chuck pressing / separating portion 400 is moved upward from the state of the side simplified view of FIG. 4. As shown in FIG. 5, even when the tip chuck pushing / separating portion 400 is moved upward and the rightmost protrusion 410a and the leftmost protrusion 410b are moved upward by the same stroke along with the movement, The rightmost protrusion 410a that pushes the point closes the chuck first. In this way, the chuck that is pushed by the pressing point close to the fulcrum is closed first, so that the chuck can be closed in order from the end, and the original plate can be gripped while wrinkles are extended.
[0046]
Here, the example in which the rightmost chuck is applied as the predetermined chuck according to the present invention has been described above. However, the predetermined chuck does not need to be the outermost chuck, for example, a central chuck is applied. It may be a thing.
[0047]
In the above description, the image exposure apparatus that changes the stroke for pushing and releasing the chuck according to the length of the protrusion has been described. However, the drum-type exposure apparatus of the present invention has an inclination of the first portion of the chuck with the protrusion as a fixed length. It may be a drum type exposure apparatus that changes the stroke at which the protrusion pushes and separates the chuck.
[0048]
In the above description, the image exposure apparatus having the tip chuck mounted on the drum in advance has been described. However, the drum-type exposure apparatus of the present invention has the tip chuck attached to the drum before gripping the end of the original. A drum type exposure apparatus may be used.
[0049]
Further, in the above, an example in which the sheet material fixing device of the present invention is applied to an image exposure apparatus has been described. However, this sheet material fixing device may be any device that operates by mounting a sheet on a drum, and is a drum type exposure. You may apply to apparatuses other than an apparatus.
[0050]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a sheet material fixing apparatus and a drum type exposure apparatus that open a sheet wrinkle and mount the sheet at a correct position on the drum.
[Brief description of the drawings]
FIG. 1 is a schematic block diagram showing a part of an image exposure apparatus to which an embodiment of the present invention is applied.
FIG. 2 is a front view of the image exposure apparatus 10 shown in FIG.
FIG. 3 is a perspective view of the drum 100 and the tip chuck pressing / separating portion 400 as viewed from the rightmost chuck 110a side.
FIG. 4 is a top view of the rightmost tip chuck 110a and the leftmost tip chuck 110b, and a simplified side view of the drum 100 and the tip chuck pushing / separating portion 400 as viewed from the side.
5 is a simplified side view of the drum 100 and the tip chuck pushing portion 400 when viewed from the side when the tip chuck pushing portion 400 is moved upward from the state of the side view of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Image exposure apparatus 100 Drum 110 Front end chuck | zipper 110a The rightmost front end chuck | zipper 110b The leftmost front end chuck | zipper 112 Pushing part 113 Sheet | seat holding part 114 Elastic member 200 Feeding / discharging plate unit 210 Discharging guide 220 Feeding guide 300 320 Rear end chuck 400 Front end chuck pushing / separating part 410 Protrusion 410a Rightmost protrusion 410b Leftmost protrusion 500 Roller 600 Exposure part

Claims (3)

The drum and the second part, each having a first part and a second part sandwiching a fulcrum, mounted on a drum that rotates by winding a sheet material around the circumferential surface. A chuck for sandwiching the sheet material therebetween,
The plurality of chucks have a plurality of protrusions projecting toward the chuck in a one-to-one correspondence, and the first portions of the corresponding chucks are separated from each other by the tips of the protrusions. A position where the sheet material is fixed between the chuck and the chuck located closer to the predetermined chuck among the plurality of chucks is pushed away from a point closer to the fulcrum on the first portion, and is located farther from the predetermined chuck. And a chuck pressing / separating portion that presses and separates a point farther from the fulcrum on the first portion as the chuck is located. The sheet material fixing device according to claim 1, wherein the chuck pressing / separating portion has a protrusion whose length is shorter as the protrusion is closer to the predetermined chuck. In a drum type exposure apparatus that rotates a drum around which a sheet-shaped photosensitive material is wound, and scans the photosensitive material on the drum with light in the direction of the rotation axis of the drum to expose the photosensitive material.
The photosensitive material is sandwiched between the drum and the second part, each of which has a first and a second part sandwiching a fulcrum and mounted on the drum in the direction of the rotation axis of the drum. A chuck
The plurality of chucks have a plurality of protrusions projecting toward the chuck in a one-to-one correspondence, and the first portions of the corresponding chucks are separated from each other by the tips of the protrusions. The position closer to the fulcrum on the first portion of the plurality of chucks that fix the photosensitive material between the drum and closer to the predetermined chuck is pushed away and the position farther from the predetermined chuck. A drum type exposure apparatus comprising: a chuck pressing portion that presses and separates a point farther from the fulcrum on the first portion as the chuck is located.

Images