JP2537120B2 - Exposure device for electrophotographic gray-scale photo reproduction device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus for an electrophotographic tone reproduction apparatus. More specifically, the present invention relates to an exposure device of an electro-processed gray-scale photo reproduction device having a simplified exposure mechanism.

[0002]

2. Description of the Related Art Conventionally, an exposure apparatus shown in FIGS. 3 to 7 has been used in an electrophotographic tone reproduction apparatus (hereinafter referred to as a reproduction apparatus).

In the exposure apparatus A shown in FIG. 3, a condenser lens A2 is arranged on the central axis of the semi-cylindrical body A1 for holding the film, and a reflecting mirror for deflecting the optical path from the condenser lens A2 by 90 degrees to the tip of the rotating shaft. An optical system including a scan motor A3 provided with an MR is arranged, and a condenser lens A2 of this optical system is arranged.
By irradiating the laser beam L from the laser optical processing system A4 through the reflecting mirrors M1 and M2, the film F held on the inner surface of the film holding semi-cylindrical body A1 is exposed. Then, by rotating the reflection mirror MR, the film F is exposed in the circumferential direction. In the exposure of the film F in the longitudinal direction (the direction of the central axis of the semi-cylindrical body A1), the infinite belt A5 having an optical system stretched is suspended, and the infinite belt A5 is moved by the scan motor A6. And the entire film F is exposed.

4 to 5 show the scan motor A3.
4A and 4B show a case where the rotary shaft is rotated in a fixed direction, and FIG. 5 shows a case where the rotary shaft reciprocates (swings) within a fixed range. Therefore, the laser beam L from the condensing lens A2 makes a rotary circular motion in the case of FIG. 4 and a reciprocating arc motion in the case of FIG. 5 on the film F surface.

In the exposure apparatus B shown in FIG. 6, the galvano scanner B2 for the film F wound on the drum B1 is used.
The laser beam L deflected by the
The film F is exposed in the longitudinal direction by being deflected by 3, and the drum B1 on which the film F is wound is rotated by the motor B4 to be exposed in the circumferential direction. In the exposure apparatus B shown in FIG. 6,
In this way, the entire film F is exposed.

In the exposure apparatus C shown in FIG. 7, the galvano scanner C for the film F sandwiched between the rollers C1 and C1 is used.
The laser beam L deflected by 2 is further deflected by the fθ lens C3 to expose the film F in the width direction, and the roller C sandwiching the film F.
By rotating 1 and C1 by the motor C4, the film F is exposed in the longitudinal direction, and thus the entire film F is exposed.

However, the exposure apparatuses A, B, and C shown in each of the drawings have the following problems, and further improvement is desired.

If an image having no problem in practical use is to be obtained by using the exposure apparatus A shown in FIG.
When the film F of mm × 350 mm is used, it is necessary to suppress the error of the axial parallelism of the optical system to 1 μm or less on the surface of the film F and the change of the moving speed of the optical system to 1 μm / sec or less on the surface of the film F. For this purpose, it is necessary to suppress the extension of the infinite belt A5 on which the optical system is suspended to be 1 μm or less and to make the friction of the pulley A7 driving the infinite belt A5 with the infinite belt A5 constant. However, the optical system including the condenser lens A2, the scan motor A3, and the reflection mirror MR has a considerable weight, and
It also has inertia due to rotation of the scan motor A3 and the reflection mirror MR. Therefore, it is considerably difficult to maintain the elongation and friction of the infinite belt A5 as described above. Therefore, in the exposure apparatus A shown in FIG. 3, maintenance for adjusting the tension of the belt A5 is frequently performed. Moreover, it is still difficult to obtain a photograph with a predetermined accuracy.

In the exposure apparatus A shown in FIG. 3, when the scan motor A3 is driven by the method shown in FIG. 4, if the size of one pixel is 100 μm × 100 μm, the number of lines is 4,500 (450 mm / 100 μm).
Becomes Here, assuming that the exposure time of the entire film F is 10 seconds, the exposure time per line is about 2.2 milliseconds (10 seconds / 4500 lines). Further, assuming that effective exposure is performed by 1/3 of the rotated portion of the laser beam L, the time required for one rotation of the scan motor A3 is about 6.6 milliseconds. That is, about 151 per second
Need to rotate. 90 when converted to RPM
It will be 60 RPM. Therefore, when the scan motor A3 is rotated by the method shown in FIG. 4, there is a problem in that it must be rotated at a high speed of 9000 RPM. In addition, it has the essential drawback that only one third of its rotating part is available.

Further, when the scan motor A3 is driven by the method shown in FIG. 5, inertia occurs due to reciprocating motion, so that it becomes more difficult to ensure accuracy. In addition, there is also an essential disadvantage that only half of the operating portion can be used because exposure is performed on the forward path and not performed on the return path due to reciprocation.

When the exposure apparatus B shown in FIG. 6 is used,
If a polyhedral mirror is attached to the tip of the rotary shaft of the scanner motor, most of the above problems can be solved, but a film F using a nitrocellulose film or polyester film having a thickness of 0.15 mm as a base material is wound around the drum B1. In order to obtain a perfect circular shape, it is necessary to completely press both ends of the film F. Therefore, there is a problem that the pressed portion cannot be exposed and the effective use area of the film F is reduced. In addition, since the unexposed portion becomes blank after development, there is a problem that the image photographed on the film F becomes difficult to see.

When the exposure apparatus C shown in FIG. 7 is used,
Similar to the device B shown in FIG. 6, there is no problem as in the device A shown in FIG. 3, but in order to obtain an image having no practical problems, it is necessary to feed the film F uniformly by the rollers C1 and C1. . For this purpose, the thickness of the film F must be uniform, and the thicknesses of the rollers C1 and C1 and the clamping load by the rollers C1 and C1 must be uniform. However, the thickness of the film F is uneven, and due to the processing accuracy of the rollers C1 and C1, the roller C
It is difficult to make the diameters of C1 and C1 uniform and it is difficult to hold the film F with a uniform clamping force because of the manufacturing precision of the bearing. Further, when the film F is held by the rollers C1 and C1, it elastically deforms, but the deformation does not occur uniformly. Therefore, there is a problem that an image with desired accuracy cannot be obtained because the film F sent by the rollers C1 and C1 is fed one-sided or has fine irregularities on the surface of the film F.

The exposure apparatuses B and C shown in FIGS.
When a polyhedral mirror is adopted in, the wind caused by the rotation of the polyhedral mirror is reflected from the walls in the exposure apparatus and randomly collides with the polyhedral mirror, so that the rotation axis irregularly shakes and the image is disturbed. Therefore, there is also a problem that a special correction mechanism is required to correct the image distortion.

[0014]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art. In spite of its simple structure, the problems described above have been solved, resulting in high-quality electric processing density. It is an object of the present invention to provide an exposure device of an electrophotographic gray-scale photo reproduction device capable of obtaining a photograph.

[0015]

SUMMARY OF THE INVENTION An exposure apparatus for an electro-processed gray-scale photo reproduction apparatus according to the present invention comprises a light projecting means, a rotating polyhedron reflecting means, a light deflecting / focusing means, an optical system holding means, and a rotating means. Means and a film holding means, the light projecting means irradiates a parallel light beam, the rotating polyhedral reflecting means reflects the parallel light beam from the light projecting means to the light deflecting / focusing means,
The light deflecting / condensing means collects the light beam reflected from the rotating polyhedral reflecting means at a predetermined position on the film,
The optical system holding means integrally holds the light projecting means, the rotating polyhedron reflecting means, and the light deflecting / focusing means,
The film holding means has a film holding surface formed in an arc shape, and the rotating means rotates the optical system holding means in a predetermined range about a center of curvature of the film holding surface, whereby It is characterized in that a predetermined area of the film held on the film holding surface is exposed.

In the exposure apparatus of the electrophotographic tone reproduction apparatus of the present invention, a combination of a laser device and a parallel optical system is used as the light projecting means, and a polygon mirror is used as the rotating polyhedron. It is preferable that an fθ lens is used as the light deflecting / focusing means.

Further, in the exposure apparatus of the electro-processed gray-scale photo reproduction apparatus of the present invention, there is provided a structure comprising the light projecting means, the rotating polyhedral reflecting means, the light deflecting / focusing means and the optical system holding means. The center of gravity is preferably on the rotation axis of the rotation means or between the rotation axis of the rotation means and the film holding surface.

Further, in the exposure apparatus of the electrophotographic tone reproduction apparatus of the present invention, the radius of curvature of the film holding surface secures the slip of the film slipping down from the film supply device provided on the upper part, and It is preferable that the size is set to fit naturally.

Moreover, in the exposure apparatus of the electrophotographic tone reproduction apparatus of the present invention, a film guide projection and / or a stopper is provided on the film holding surface, or the film holding means has a film suction mechanism. It is preferable to have.

[0020]

Since the exposure apparatus of the electrophotographic tone reproduction apparatus of the present invention adopts the above-mentioned construction, the entire optical system can be moved at a high speed only by rotating the rotating polyhedral reflecting means at a high speed. A predetermined range including the entire film can be exposed without moving the film.
Therefore, an accurate image can be produced.
Moreover, in this case, since the rotating polyhedron reflecting means rotates integrally with the optical system holding means, the rotating shaft of the rotating polyhedron is constantly subjected to a force for returning it to its original position by the so-called gyro effect. become. Therefore, even if the wind generated by the rotation of the rotating polyhedron is reflected from the wall or the like in the exposure apparatus and randomly hits the rotating polyhedron, the rotation axis does not swing. Therefore, there is no image distortion caused by the swing of the rotation axis. Therefore, it is not necessary to provide any means for correcting the image disturbance.

Further, the center of gravity of the structure comprising the light projecting means, the rotating polyhedron reflecting means, the light deflecting / focusing means, and the optical system holding means is on the rotation axis of the rotation means or the rotation of the rotation means. In a preferred embodiment between the axis and the film-holding surface, the structure naturally descends due to its own weight, so exposure to the film surface should be done from top to bottom as the structure descends. Since the entire film can be exposed only by appropriately controlling the descending speed, it is easy to control the drive unit of the rotating means.

Further, in a preferred embodiment, the radius of curvature of the film holding surface is set to a size that ensures the sliding of the film sliding down from the film supply device provided at the upper part and that the film naturally fits in. , The film is naturally set on the film holding surface without applying any special force to the film.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described based on embodiments with reference to the accompanying drawings, but the present invention is not limited to such embodiments.

FIG. 1 is a principle diagram of one embodiment of the present invention, and FIG. 2 is a schematic diagram of the same embodiment. In the figure, 1 is a light projecting means,
Reference numeral 2 is a rotating polyhedron reflecting means, 3 is a light deflecting / condensing means, 4 is an optical system holding means, 5 is a turning means, 6 is a film holding means, F is a film, and L is a light beam.

An embodiment of the present invention, the principle of which is shown in FIG. 1 and the outline thereof is shown in FIG. 2, includes a light projecting means 1, a rotating polyhedral reflecting means 2, a light deflecting / converging means 3, and an optical system. The system holding means 4, the turning means 5 and the film holding means 6 are main constituent elements.

In the present embodiment, the light beam L emitted by the light projecting means 1 is reflected by the rotating polyhedral reflecting means 2 and is incident on the light deflecting / condensing means 3. Then, the film F which is deflected by the light deflecting / focusing means 3 and is held on the arc-shaped film holding surface 61 of the film holding means 6
It is focused at a predetermined position on the surface. As a result, the surface of the film F is exposed. The light beam condensed on the surface of the film F moves laterally on the surface of the film F as the rotating polyhedral reflecting means 2 rotates. That is, scanning of the film surface is performed by the rotation of the rotating polyhedral reflecting means 2. As a result, the lateral exposure of the surface of the film F is performed. Therefore, the light projecting means 1, the rotating polyhedron reflecting means 2, and the light deflecting / focusing means 3 are held by the optical system holding means 4 in such a positional relationship as to constitute such an optical system. Then, each time one scan is completed, the rotating means 5 is intermittently operated to rotate the optical system holding means 4 by a predetermined angle, thereby sequentially lowering the optical system holding means 4 from top to bottom, The vertical exposure on the surface of the film F is also performed. Therefore, the axis of the rotating shaft of the rotating means 5 is aligned with the center of curvature of the arc-shaped film holding surface 61.

The above-mentioned operations are performed based on commands from a control device (not shown).

Here, as the light projecting means 1, for example, a light projecting device including a semiconductor laser and a parallel optical system is used. The irradiation of light from the light projecting means 1 is adjusted by a control signal from an image processing device (not shown).

As the rotating polyhedron reflecting means 2, for example, one in which a polygon mirror 21 is rotated by a scanner motor 22 is used. As the polygon mirror 21 and the scanner motor, those conventionally used in laser optical devices are preferably used.

The light deflecting / focusing means 3 is, for example, fθ.
A lens is used. In addition, the mounting is the film F
The focus is on the surface.

As the optical system holding means 4, the light projecting means 1,
The base material 41 has such a size and strength that the rotating polyhedron reflecting means 2 and the light deflecting / condensing means 3 can be arranged so as to satisfy the above relationship, and has strength enough to withstand the rotation of the rotating means 5.
And a cover 4 for preventing light from entering the light path from the other.
2 is used. The light projecting means 1, the rotating polyhedron reflecting means 2 and the light deflecting / focusing means 3 are provided.
Are attached to the base material 41 by appropriate means while maintaining the positional relationship.

In the present embodiment, the center of gravity of the structure comprising the light projecting means 1, the rotating polyhedron reflecting means 2, the light deflecting / reflecting means 3 and the optical system holding means 4 is on the rotation axis of the rotation means 5 or It is set in front of it (on the side of the film F).
By doing so, the control when the optical system holding means 4 is lowered (during exposure) by the rotating means 5 becomes easy.

As the rotating means 5, for example, a combination of a step motor 51 and a rotary shaft 52 is used. The tip of the rotary shaft 51a of the step motor 51 is attached to the base material 41 of the optical system holding means by an appropriate means, for example, on the side surface of the base material 41. On the other hand, the step motor 51 is attached to the inner surface of the exposure apparatus by appropriate means. Further, one end 52a of the rotary shaft 52 is also attached to the side surface of the base material 41 on the opposite side to which the rotary shaft 51a of the step motor 51 is attached by an appropriate means. On the other hand, the other end 52b of the rotary shaft 52 is rotatably held on the inner surface of the exposure apparatus. And step motor 5
The axis of the first rotating shaft 51a and the axis of the rotating shaft 52 are arranged so as to coincide with the center of curvature of the film holding surface 61.

The film holding means 6 has the arcuate film holding surface 61 as described above. The radius of curvature of the film holding surface 61 is set to such a size that the film F naturally bends and fits without hindering the sliding down of the film supplied from the film supply device (not shown). The specific numerical value is obtained by, for example, an experiment. Now, the film size is, for example, 450 mm x 35
If it is 0 mm, this radius of curvature is 250 m.
The range is from m to 350 mm. A stopper (not shown) is provided below the film holding surface 61 so that the film F stands still at the most stable position. The position of this stopper is also determined by experiments. Further, guides (not shown) for guiding the sliding of the film F are provided on both sides of the film holding surface 61. The mounting position of this guide may be adjusted according to the film size.

Further, the film holding surface 61 has a double structure,
The so-called drum shape is provided with an opening on the upper surface, and the air between the film F and the upper surface is discharged by an exhaust device connected to the lower surface, so that the film F is held on the film holding surface 61.
You may make it adsorb | suck to.

Since the exposure apparatus of this embodiment does not cover the surface of the film F as described above, the entire film F can be exposed without any problem.

[0037]

As described above, according to the present invention, the portion that operates at high speed is only the rotating polyhedral reflecting means, and the rotating polyhedral reflecting means is stably held, so that the film is exposed accurately. it can. Therefore, an accurate photograph can be obtained.

Further, since there is no portion covering the film, the entire film can be exposed without any trouble. Therefore, there is no unexposed portion at the upper end, lower end or both ends of the obtained photograph, and a photograph that is easy to see can be obtained.

Further, since the structure is simple and the number of movable parts is small, there is an effect that maintenance is easy.

[Brief description of drawings]

FIG. 1 is a principle diagram of an embodiment of the present invention.

FIG. 2 is a schematic view of the embodiment.

FIG. 3 is a schematic view of a conventional exposure apparatus.

FIG. 4 is a schematic view of an example of a reflecting unit used in the exposure apparatus.

FIG. 5 is a schematic view of another example of the reflecting means used in the exposure apparatus.

FIG. 6 is a schematic view of another example of the conventional exposure apparatus.

FIG. 7 is a schematic view of another example of the conventional exposure apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Light projecting means 2 Polyhedral rotation reflecting means 3 Light deflecting / focusing means 4 Optical system holding means 5 Rotating means 6 Film holding means F Film L Light beam (laser beam)

Claims (7)

(57) [Claims] 1. A light projecting means, a rotating polyhedron reflecting means, a light deflecting / focusing means, an optical system holding means, a rotating means, and a film holding means, wherein the light projecting means emits parallel rays. The rotating polyhedron reflecting means reflects the parallel light beam from the light projecting means to the light deflecting / focusing means, and the light deflecting / focusing means is reflected from the rotating polyhedron reflector. The light beam is condensed at a predetermined position on the film, the optical system holding unit integrally holds the light projecting unit, the rotating polyhedral reflecting unit, and the light deflecting / focusing unit, and the film holding unit is , Having a film holding surface formed in an arc shape, the rotating means rotates the optical system holding means within a predetermined range about a center of curvature of the film holding surface, thereby holding the film holding surface on the film holding surface. The specified area of the film being exposed Exposure apparatus electrical processing grayscale photographic reproduction apparatus characterized by comprising been. 2. A combination of a laser device and a parallel optical system is used as the light projecting means, a polygon mirror is used as the rotating polyhedron, and an fθ lens is used as the light deflecting / focusing means. The exposure apparatus of the electrophotographic tone photographic reproducing apparatus according to claim 1, wherein 3. The center of gravity of a structure including the light projecting means, the rotating polyhedron reflecting means, the light deflecting / focusing means, and the optical system holding means is on the rotation axis of the rotation means or the rotation. 3. An exposure apparatus for an electrophotographic tone reproduction apparatus according to claim 1, wherein the exposure apparatus is located between a rotation axis of a moving means and the film holding surface. 4. The radius of curvature of the film holding surface is set to a size that ensures slippage of the film sliding down from the film supply device provided on the upper part and that the film naturally fits. The exposure apparatus of the electrophotographic gray-scale photo reproduction apparatus according to claim 1, 2 or 3. 5. The exposure apparatus of the electrophotographic tone reproduction apparatus according to claim 1, wherein the film holding surface is provided with a film guide projection and / or a stopper. 6. The film holding means comprises a film suction mechanism.
Or the exposure device of the electrophotographic gray-scale photo reproduction device according to item 5. 7. An electro-processed gray-scale photo reproduction apparatus comprising the exposure apparatus according to claim 1, 2, 3, 4, 5 or 6.