JPH08220458A - Exposure device - Google Patents

Abstract

PURPOSE: To improve image quality by lowering the visibility of irregular subscanning pitch. CONSTITUTION: Light beams radiated from semiconductor lasers 258C, 258M and 258Y are made incident on a polygon mirror 264 through a collimator lens 260, a cylindrical lens 263, and a reflection mirror 262. The polygon mirror 264 has six reflection surfaces 268 and is rotated centering around a shaft 266 at high speed, so that the light is deflected by consecutively changing the incident angle of the light beam on each reflection surface 268. A distance (d) between the respective light beams radiated from the lasers 258C, 258M and 258Y at the same time in a subscanning direction is set in the range of m.L<=d<=m.m(np-1).L. Provided that the subscanning distance of the light beam is L, the number of the reflection surfaces 268 is (np) and (m) is an integer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus, and more specifically, it mainly scans a light beam emitted from a light source, and relatively moves the light beam and a light-sensitive material to be exposed to a sub-light. The present invention relates to an exposure device that scans to expose a photosensitive material.

[0002]

2. Description of the Related Art In an exposure apparatus that scans and exposes a photosensitive material using a rotating deflector such as a polygon mirror, the emission time and emission intensity of a semiconductor laser, which is a light source, is controlled so as to correspond to information or images to be recorded. Information is recorded and images are formed by exposing a photosensitive material while deflecting a light beam generated from a semiconductor laser by a polygon mirror in the main scanning direction.

Among such exposure apparatuses, for example, in a full-color digital printer or the like, the spot positions of the light beams along the sub-scanning direction of the respective colors are made to coincide with each other from the viewpoint of preventing image quality deterioration due to color shift. Along with this, the visibility of the sub-scanning pitch unevenness, which is the pitch unevenness in the sub-scanning direction caused by the surface tilt of the polygon mirror, becomes high,
There is a drawback that the quality of the image output on the photosensitive material is deteriorated.

Along with this, the specification of the sub-scanning pitch deviation of the exposure apparatus has to be tightened, and as a result, the manufacturing cost of the exposure apparatus has increased.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above facts, and reduces the visibility of unevenness in the sub-scanning pitch to improve the image quality of an output image, and further reduces the cost of the apparatus. It is an object of the present invention to provide an exposure apparatus capable of achieving the above.

[0006]

According to another aspect of the present invention, there is provided an exposure apparatus, wherein a light beam emitted from each of a plurality of light sources is reflected by a deflector having a plurality of reflection surfaces to be deflected.
An exposure apparatus that scans on a photosensitive material along a main scanning direction, moves the photosensitive material along a sub-scanning direction orthogonal to the main scanning direction, and forms an image on the photosensitive material, The irradiation positions of the light beams from the plurality of light sources on the photosensitive material are different from each other along the sub-scanning direction, and the sub-scanning interval of the light beams is set to L, and the reflection surface of the deflector is When the number of surfaces is np and m is a natural number, the irradiation position interval d on the photosensitive material along the sub-scanning direction between the light beams simultaneously emitted from different light sources is m. It is characterized in that the range is determined by the equation L≤d≤m. (Np-1) .L.

[0007]

The operation of the exposure apparatus according to the first aspect will be described below.

The light beams respectively generated by the plurality of light sources are deflected by the deflectors and sent to the photosensitive material side while scanning along the main scanning direction. Along with this, the light beams from the plurality of light sources are relatively moved with respect to the photosensitive material in the sub-scanning direction orthogonal to the main scanning direction,
An image is formed on the photosensitive material.

At this time, the irradiation positions of the light beams from the respective light sources are different from each other along the sub-scanning direction which is a direction orthogonal to the main scanning direction, and the light beams are simultaneously irradiated from different light sources. The distance d between the irradiation positions of the light beams on the photosensitive material along the sub-scanning direction is m · L ≦ d ≦ m ·
The range is (np-1) .L.

However, the sub-scanning interval of the light beam is L, the number of reflecting surfaces of the deflector is np, and m is a natural number.

Therefore, the irradiation position interval d on the photosensitive material is
Is a value in the range of m · L or more and m · (np −1) · L or less, and the spatial frequency of unevenness in the sub-scanning pitch is equal to the irradiation position of the light beam from each light source. On the other hand, it becomes higher. Then, since the spatial frequency of the unevenness of the sub-scanning pitch becomes high, the visibility of the unevenness of the sub-scanning pitch decreases, and the image quality of the image output on the photosensitive material is improved.

Along with this, the specification of the sub-scanning pitch deviation of the exposure apparatus can be relaxed, and the cost of the exposure apparatus can be reduced.

[0013]

EXAMPLES Photosensitive materials used in the examples of the present invention will be described in detail first.

The photosensitive material that can be used in the exposure apparatus of the present invention is one that can obtain a visible image by subjecting a latent image obtained by imagewise exposure to a predetermined visualization process. Anything will do as long as it is available.

For example, conventional color photographic light-sensitive materials (negative film, reversal film, color photographic paper, etc.),
Examples thereof include color diffusion transfer photosensitive materials, color photothermographic materials, color photosensitive pressure-sensitive materials, and the like.

When a positive image is recorded using a positive original as an original image, a so-called positive-positive type photosensitive material is used for each of the above-mentioned photosensitive materials, and when a positive image is recorded using a negative original, a so-called negative is used. A positive type photosensitive material can be used.

The positive-positive type light-sensitive material is a color light-sensitive material using a direct positive emulsion, for example, JP-A-63-106656, a color reversal film, for example, JP-A-4-366836, and a color diffusion transfer light-sensitive material. For example, JP-A-5-323550,
Examples of color photothermographic materials include JP-A-5-939.
94, JP-A-6-161070, JP-A-6-289.
No. 555, and the color light and pressure sensitive materials described in, for example, JP-A-61-278849 can be used.

As the negative-positive type light-sensitive material, a color heat-developable light-sensitive material, for example, JP-A-5-181 can be used.
No. 246, JP-A-6-242546 and the like can be used.

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a schematic overall configuration diagram of an image recording apparatus 10 having an exposure device 38 of this embodiment built therein. Further, FIG. 2 shows an external view of the image recording apparatus 10.

The image recording apparatus 10 is, as shown in FIG.
It is configured as a box as a whole, and a front door 13 and a side door 15 are attached to the machine base 12. The inside of the machine base 12 can be exposed by opening each door.

As shown in FIG. 1, a photosensitive material magazine 14 is arranged in the machine base 12 of the image recording apparatus 10, and the photothermographic material 16 is wound into a roll and accommodated therein. The photothermographic material 16 is wound so that the photosensitive (exposure) surface faces the lower side of the apparatus.

The photothermographic material basically has a photosensitive silver halide, a reducing agent, a binder, and a dye-providing compound (which may also serve as the reducing agent) on a support. Further, if necessary, an organic metal salt oxidizing agent and the like can be added.

The photothermographic material described above may give a negative image or a positive image upon exposure. As a method of giving a positive image, a method of directly using a positive emulsion (a method using a nucleating agent and a light fog method) as a silver halide emulsion, a dye which emits a positive diffusible dye image Any of the methods using a donor compound can be adopted.

As the photothermographic material of the type which gives a positive image, for example, those described in JP-A-6-161070 and JP-A-6-289555 can be used. Examples of the developing photosensitive material include JP-A-5-181246 and JP-A-6-24254.
Those described in No. 6 and the like can be used.

A nipping roller 18 and a cutter 20 are arranged in the vicinity of the photosensitive material take-out port of the photosensitive material magazine 14, so that the photothermographic material 16 can be pulled out from the photosensitive material magazine 14 by a predetermined length and then cut.

A plurality of conveying rollers 19, 21, 23, 24, 26 and a guide plate 27 are arranged on the side of the cutter 20, and the photothermographic material 1 is cut into a predetermined length.
6 can be transported to the exposure unit 22.

The exposing section 22 is located between the carrying rollers 23 and 24, and the exposing section (exposure point) is defined between these carrying rollers so that the photothermographic material 16 can pass therethrough. There is. Therefore, the photothermographic material 16 is transported by the transport rollers 23 and 24 along the sub-scanning direction.

An exposure device 38 is provided directly above the exposure unit 22. As shown in FIGS. 3 and 4, the exposure apparatus 3
8 is a semiconductor laser 25 as a light source for cyan color development.
8C (emission wavelength 750 nm), a semiconductor laser 258M (emission wavelength 680 nm) as a light source for magenta color development, and
Semiconductor laser 258Y as a light source for yellow color development
(Emission wavelength of 810 nm) are arranged respectively.

These semiconductor lasers 258C, 258M,
In the vicinity of the emission side of 258Y, each semiconductor laser 258C,
Collimator lenses 260 that convert the light beams emitted from 258M and 258Y into parallel rays are provided. The respective light beams converted into parallel rays by the collimator lens 260 enter the reflection mirror 262 through the cylindrical lens 263, are reflected by the reflection mirror 262, and are combined into a polygon mirror serving as a deflector. The light is incident on the polygon mirror 264. The cylindrical lens 263 is the polygon mirror 2
It has a role of correcting the surface tilt of each of the 64 reflecting surfaces 268.

Further, the polygon me 264 has a reflecting surface 26.
It has 6 surfaces 8 and is rotated at a high speed by a motor (not shown) about the axis 266, and has a role of continuously changing and deflecting the incident angle of the light beam to each reflecting surface 268. That is, the polygon mirror 264 is adapted to deflect the light beams respectively and to scan the light beams in the main scanning direction while sending the light beams to the photothermographic material 16 side. In this embodiment, the rotation speed of the polygon mirror 264 is 125 rotations per second.

The light beam main-scanned by the polygon mirror 264 is reflected via an image forming optical system 270 as an image forming means including an Fθ lens composed of a concave plano lens 275, a plano-convex lens 276 and a concave-convex lens 277. Mirror 2
The light is reflected at 72 and 274 and reaches the exposure unit 22. The reflection mirror 274 is the reflection mirror 2
It is inclined at a predetermined angle so that the light beam reflected by 72 is reflected vertically downward.

As described above, in the exposure unit 22, while the photothermographic material 16 is sub-scanned by the transport rollers 23 and 24, the main scanning of the light beam is repeated to record one image.

That is, the number of polygon mirrors 264 is 1 per second.
It rotates at a high speed of 25 rotations and the light beam is mainly scanned,
So that the sub-scanning interval L is, for example, 15.875 μm,
The photothermographic material 16 is sub-scanned by the transport rollers 23 and 24.

Each semiconductor laser 258C, 258M, 25
The light beam emitted from 8Y is applied to the photothermographic material 16, but on the photothermographic material 16 as shown in FIG.
As shown in, a light beam M for developing magenta
And the light beam C for developing cyan are separated from each other in the sub-scanning direction by 31.75 μm, which is twice the sub-scanning interval L. The beam spot distance between the light beam C for developing cyan and the light beam Y for developing yellow is 31.75 μm apart from each other in the sub-scanning direction. Therefore, the beam spot interval between the light beam M for developing magenta and the light beam Y for developing yellow is 63.5 μm apart from each other in the sub-scanning direction.

That is, the semiconductor lasers 258C and 258 are arranged along the sub-scanning direction orthogonal to the main scanning direction.
The beam spot positions which are the irradiation positions of the light beams from M and 258Y are different from each other. And three semiconductor lasers 258C, 258M, 258
The irradiation position interval d between the light beams simultaneously irradiated from Y along the sub-scanning direction is m · L ≦ d ≦ m · (np −
1) · L × 1 × 1 obtained by substituting the specifications of the present embodiment into the formula
The range is set to 5.875 ≦ d ≦ 1 × 5 × 15.875.

However, the sub-scanning interval of the light beam is L, and the number of reflecting surfaces 268 of the polygon mirror 264 is np.
Let m be a natural number. In this case, np = 6 and m = 1
And

From the above, the irradiation position interval d is 15.87.
The range is 5 μm or more and 79.375 μm or less, which corresponds to the above-mentioned beam spot interval value.

On the other hand, the exposure amount is controlled by each semiconductor laser 2
The pulse widths of the pulse signals output from 58C, 258M, and 258Y are modulated by changing the pulse width.

That is, the outputs from the semiconductor lasers 258C, 258M, and 258Y are set to a predetermined frequency (f ₀ ) in advance according to the number of pixels for one main scan, and each pulse is made to correspond to each pixel. By changing the pulse width for each one pulse, the exposure amount for each pixel can be controlled. This exposure amount is calculated based on the image signal input to the control device 206 as shown in FIG.

On the other hand, as shown in FIG. 1, a switchback section 40 is provided on the side of the exposure section 22, and a water coating section 62 is provided below the exposure section 22. The photothermographic material 16 that has risen up the side of the photosensitive material magazine 14 and has been exposed in the exposure section 22 is once fed to the switchback section 40, and then is conveyed to the lower side of the exposure section 22 by the reverse rotation of the transport roller 26. It is configured to be fed to the water coating section 62 through the provided transport path. A plurality of pipes are connected to the water application section 62 so that water can be supplied. A heat development transfer section 104 is arranged on the side of the water application section 62 so that the water development applied photothermographic material 16 is fed.

The water is not limited to so-called pure water, but includes water in a widely and commonly used meaning. Further, a mixed solvent of pure water and a low boiling point solvent such as methanol, DMF, acetone or diisobutyl ketone may be used.

Further, an image formation accelerator, an antifoggant,
A solution containing a development terminator, a hydrophilic thermal solvent, etc. may be used.

On the other hand, the machine base 12 on the side of the photosensitive material magazine 14
An image receiving material 106 is provided in the image receiving material 1
08 is rolled up and stored. A dye fixing material having a mordant is applied to the image forming surface of the image receiving material 108, and the image forming surface is wound toward the upper side of the apparatus.

The receiving material magazine 106 is the sensitive material magazine 14
Similarly to the above, it is composed of a body portion and a pair of side frame portions fixed to both end portions of the body portion, and the front side of the machine base 12 (the front side of the plane of FIG. 1; that is, the width of the rolled image receiving material 108). direction)
It is possible to withdraw to.

A nip roller 110 is arranged in the vicinity of the image receiving material take-out port of the material receiving magazine 106 so that the image receiving material 108 can be pulled out from the material receiving magazine 106 and the nip can be released. A cutter 112 is arranged beside the nip roller 110.

On the side of the cutter 112, the photosensitive material magazine 1
An image receiving material transporting section 180 located on the side of 4 is provided. The image receiving material transport unit 180 includes a transport roller 186,
190, 114 and a guide plate 182 are arranged, and the image receiving material 108 cut into a predetermined length can be conveyed to the heat development transfer section 104.

The heat-developable photosensitive material 16 conveyed to the heat-development transfer section 104 includes the bonding roller 120 and the heating drum 1.
16, the image receiving material 108 is synchronized with the conveyance of the photothermographic material 16, and the photothermographic material 16 is advanced by a predetermined length between the bonding roller 120 and the heating drum 116. It is sent and can be overlaid. A pair of halogen lamps 132A and 132B are arranged inside the heating drum 116 so that the surface of the heating drum 116 can be heated.

The endless pressure contact belt 118 is wound around five winding rollers 134, 135, 136, 138 and 140, and the endless outer side between the winding rollers 134 and 140 is heated. It is pressed against the outer periphery of the drum 116.

A bending guide roller 142 is provided below the heating drum 116 downstream of the endless pressure contact belt 118 in the material supply direction.
Is arranged. A peeling claw 154 is rotatably supported by a shaft below the heating drum 116 on the downstream side of the bending guide roller 142 in the material supply direction.

The photothermographic material 16 peeled by the peeling claw 154 is wound around the bending guide roller 142,
It is accumulated in the waste photosensitive material storage box 178.

A peeling roller 174 and a peeling claw 176 are arranged near the heating drum 116 on the side of the bending guide roller 142. Peeling roller 174 and peeling claw 176
A receiving material guide 170 is arranged below the receiving material discharge rollers 172, 173, and 175.
The peeling roller 174 and the peeling claw 176 can guide and convey the image receiving material 108 peeled from the heating drum 116.

The image receiving material 108 peeled from the outer periphery of the heating drum 116 by the peeling claw 176 is received by the material receiving guide 170.
In addition, the material receiving rollers 172, 173, and 175 convey the sheet and discharge it to the tray 177.

As shown in FIG. 8, the controller 206 is
It is configured to include a microcomputer 240,
The microcomputer 240 includes a CPU 242 and a RAM
244, ROM 246, input / output port 248, and a bus 250 such as a data bus or a control bus that connects them.
It is composed of

An image signal S (for example, a video signal) which is a basis of an image to be recorded is input to the input / output port 248. Also, this input / output port 24
8 is a signal line 2 to the photosensitive material conveying system and the image receiving material conveying system.
52 and 254 are connected to control the drive of each drive unit and control the transport of the photosensitive material or the image receiving material.

Further, at the input / output port 248, current control units 257Y, 257M, 25 for controlling the emission timing and emission intensity of the semiconductor lasers 258Y, 258M, 258C.
7C is connected.

Next, the operation of this embodiment will be described. First, with the sensitive material magazine 14 set, the nickel roller 1
8 is operated and the photothermographic material 16 is transferred to the nip roller 18
Pulled out by. When the photothermographic material 16 is pulled out by a predetermined length, the cutter 20 operates and the photothermographic material 16 is cut into a predetermined length.

After the operation of the cutter 20, the photothermographic material 1
The sheet 6 is inverted and conveyed to the exposure unit 22 with its photosensitive (exposure) surface facing upward. This photothermographic material 16
The exposure device 38 is operated simultaneously with the conveyance of the sheet, and the photothermographic material 16 located in the exposure section 22 is scanned and exposed.

That is, the semiconductor lasers 258Y, 258
The respective light beams emitted by M and 258C and emitted are incident on the collimator lens 260, respectively. The light beam that has become parallel rays from the collimator lens 260 is corrected by the cylindrical lens 263 for the surface tilt of the polygon mirror 264. The optical axis of each light beam is focused by the polygon mirror 264, and each light beam is
The light is incident on each reflection surface 268 of the polygon mirror 264.

The polygon mirror 264 has a reflection surface 268 of 6
The surface is equipped with a polygon mirror 264, and a light beam is emitted every 7 seconds.
It is incident 50 times. Therefore, the light beam is incident 125 times per second on each reflecting surface 268 of the polygon mirror 264.

The rotation of the polygon mirror 264 deflects the light beam in the main scanning direction. The light beam, while being deflected in the main scanning direction, has a concave plano lens 275 and a plano-convex lens 2.
The light enters the Fθ lens having a predetermined image formation relationship, which is composed of the lens 76 and the concave-convex lens 277, is reflected upward by the reflection mirror 272, is reflected vertically downward by the reflection mirror 274, and is bonded to the photothermographic material 16. The photothermographic material 16 is exposed as an image.

At this time, as shown in FIG. 5, the photothermographic material 16 of the light beam reflected by the same reflecting surface 268.
The upper beam spot position is deviated by 31.75 μm.

Therefore, the axis 266 of the polygon mirror 264
The phase of the unevenness in the sub-scanning pitch is deviated by 31.75 μm between the light beams due to the surface tilt caused by the inclination of the light beam. The number of unevenness in the sub-scanning pitch is 10.499 Lp / mm (the number per millimeter), which is 31.496 Lp / mm.

That is, the three semiconductor lasers 258C, 2
58M and 258Y when the beam spot positions of the respective light beams are the same, and the sub-scanning interval L is 15.8.
If the reflection surface 268 of the polygon mirror 264 has six surfaces, the interval between the light beams scanned by the same reflection surface 268, that is, the cycle of unevenness in the sub-scanning pitch is 15.
From the equation of 875 μm × 6 = 95.25 μm, FIG.
Is 95.25 μm, which corresponds to the range of one rotation of the polygon mirror 264 shown in FIG. As a result, the same reflecting surface 268
The number of light beams scanned by 1 mm, that is, the number of sub-scanning pitch irregularities is 1000 μm ÷ 95.
25 μm = 10.499 (pieces).

On the other hand, in this embodiment, the intervals of the light beams scanned by the same reflecting surface 268 are 31.75 μm.
The number of sub-scanning pitch irregularities is 100
0 μm ÷ 31.75 μm = 31.496 (pieces).

Therefore, the cycle of unevenness in the sub-scanning pitch is as shown in FIG.
As shown in (a), the rotation of the polygon mirror 264 is 1/3 of one rotation, and the spatial frequency of the unevenness of the sub-scanning pitch is increased, so that the visibility of the unevenness of the sub-scanning pitch is reduced, and the image quality without unevenness is high. Can be obtained.

Further, along with this, the density unevenness shifts to the color unevenness, whereby the visibility of the unevenness is further reduced, and it is possible to further easily obtain a high-quality image without unevenness.

That is, as shown in FIG. 7, the vertical axis represents relative contrast sensitivity, the horizontal axis represents spatial frequency and video frequency, the yellow-blue chromaticity is represented by a solid line, and the red-green chromaticity is represented by a chain line. When the characteristic of light and darkness is expressed by a broken line, the spatial frequency characteristic of light and darkness and chromaticity is also a bandpass type, but the frequency of the highest sensitivity of chromaticity is a fraction of that in the case of light and darkness. However, it is known that it has been obtained.

From the above, it can be seen that, in the high frequency region, color unevenness, which is unevenness in chromaticity, is less visible than density unevenness, which is unevenness in brightness and darkness. It becomes clear that the mutually different effects become remarkable.

Further, since it is possible to easily obtain a high quality image without unevenness, it is possible to relax the specifications of the optical system for the correction of the surface error, and it is possible to reduce the cost of the exposure device 38.

Then, the pulse width of the pulse signal output from each of the semiconductor lasers 258C, 258M, and 258Y is changed so that the exposure amount calculated based on the image signal input to the control device 206 is changed, and the thermal development is performed. The photothermographic material 16 is exposed while the photosensitive material 16 is mainly scanned. In this way, in the exposure section 22, the main scanning with the light beam is repeated while the heat developing photosensitive material 16 is sub-scanned, and the heat developing photosensitive material 16 is exposed to record one image.

After the exposure is started, the exposed photothermographic material 16 is once sent to the switchback section 40 and then to the water coating section 62 by the reverse rotation of the carrying roller 26.

In the water application section 62, water is applied to the photothermographic material 16, and the squeeze roller 68 removes excess water and passes through the water application section 62.

The photothermographic material 16 coated with water as the image forming solvent in the water coating section 62 is sent to the heat development transfer section 104 by the squeeze roller 68.

On the other hand, as the scanning exposure of the photothermographic material 16 is started, the image receiving material 108 also receives the image receiving material 108.
The paper is pulled out from 06 by the nip roller 110 and conveyed. When the image receiving material 108 is pulled out by a predetermined length, the cutter 112 operates and the image receiving material 108 is cut into a predetermined length.

After the operation of the cutter 112, the guide plate 182
While being guided by the conveying rollers 190, 186, 1
The sheet is conveyed by 14, and enters a standby state immediately before the heat development transfer section 104.

In the heat development transfer section 104, when it is detected that the squeeze roller 68 has sent the photothermographic material 16 between the outer periphery of the heating drum 116 and the bonding roller 120, the conveyance of the image receiving material 108 is restarted. Then, the heating drum 116 is operated while being sent to the bonding roller 120.

In this case, the guide plate 122 is arranged between the laminating roller 120 and the squeeze roller 68 of the water application section 62, and the photothermographic material 16 sent from the squeeze roller 68 is surely laminated. Roller 12
Guided to 0.

The photothermographic material 16 and the image receiving material 108 superposed by the laminating roller 120 are sandwiched between the heating drum 116 and the endless pressure contact belt 118 in the superposed state, and the heating drum 116 is substantially Two
/ 3 laps (wrapping roller 134 and wrapping roller 140
Between)). As a result, the photothermographic material 16 and the image receiving material 108 are heated to release the movable dye, and at the same time, the dye is transferred to the dye fixing layer of the image receiving material 108 to obtain an image.

Thereafter, the photothermographic material 16 and the image receiving material 1
08 is sandwiched and conveyed to reach the lower portion of the heating drum 116, the peeling claw 154 is moved by the cam 130, and the peeling claw is moved to the front end portion of the photothermographic material 16 that is conveyed by a predetermined length before the image receiving material 108. 154 is engaged and the tip of the photothermographic material 16 is separated from the outer periphery of the heating drum 116. Further, the pinch roller 157 presses the photothermographic material 16 by the returning movement of the peeling claw 154, whereby the photothermographic material 16 is wound around the bending guide roller 142 while being pressed by the pinch roller 157 and moves downward. Then, they are collected in the waste photosensitive material storage box 178.

On the other hand, the image receiving material 108 which is separated from the photothermographic material 16 and moves while being in close contact with the heating drum 116 is sent to the peeling roller 174 and is peeled off.

The image receiving material 108 peeled from the outer periphery of the heating drum 116 by the peeling claw 176 is further wound around the peeling roller 174 and moved downward, and guided by the material receiving guide 170 while receiving the material receiving rollers 172, 1.
It is conveyed by 73, 175 and discharged to the tray 177.

Although m = 1 in this embodiment,
It may be 2 or 3 which is another natural number, and the number of reflecting surfaces of the polygon mirror may be a number other than 6. Furthermore, in the present embodiment, the exposure apparatus adopted in the image recording apparatus 10 has been described, but it goes without saying that it can be applied to other apparatuses.

[0083]

As described above, the exposure apparatus of the present invention has the effects of reducing the visibility of sub-scanning pitch unevenness, improving the image quality of the output image, and reducing the cost of the apparatus. .

[Brief description of drawings]

FIG. 1 is a schematic overall configuration diagram of an image recording apparatus incorporating an exposure apparatus of the present invention.

FIG. 2 is a perspective view showing the outer appearance of the image recording apparatus of this embodiment.

FIG. 3 is a schematic perspective view of an exposure apparatus.

FIG. 4 is a schematic view of the exposure apparatus as viewed from the vertically upper side.

FIG. 5 is an explanatory diagram showing a state in which a light beam is scanned on a photosensitive material by an exposure device.

FIGS. 6A and 6B are graphs showing a state of density unevenness when scanning is performed on a photosensitive material by an exposure device, FIG. 6A is according to the present embodiment, and FIG. 6B is according to a conventional technique. is there.

FIG. 7 is a graph showing a relationship between relative contrast sensitivity and spatial frequency.

FIG. 8 is a control block diagram.

[Explanation of symbols]

 10 image recording device 16 photothermographic material (image photosensitive material) 38 exposure device 258Y semiconductor laser (light source) 258M semiconductor laser (light source) 258C semiconductor laser (light source) 264 polygon mirror (deflector)

Claims (1)

[Claims] 1. A light beam emitted from each of a plurality of light sources is reflected by a deflector having a plurality of reflection surfaces to be deflected, and is scanned on a photosensitive material along a main scanning direction. An exposure device that moves the photosensitive material along an orthogonal sub-scanning direction to form an image on the photosensitive material, wherein an irradiation position of light beams from the plurality of light sources onto the photosensitive material is , The light beams are different from each other along the sub-scanning direction, the sub-scanning interval of the light beams is L, the number of reflecting surfaces of the deflector is np, and m is a natural number. The irradiation position interval d on the photosensitive material along the sub-scanning direction between the respective light beams simultaneously emitted from the light source is determined by the following equation: m · L ≦ d ≦ m · (np −1) · L An exposure apparatus characterized by being set in a range.