JP3501865B2 - Exposure equipment - 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, 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 deflector such as a polygon mirror, the emission time and emission intensity of a semiconductor laser are controlled so as to correspond to information or images to be recorded, and the semiconductor laser emits light. Information is recorded and images are formed by exposing the photosensitive material while deflecting the formed light beam in the main scanning direction by a polygon mirror.

In such an exposure apparatus, the SOS (Sta
The rt, Of, Scan) mirror and the SOS sensor are used to expose the photosensitive material from the main scanning start point on the photosensitive material, that is, the first exposure position (writing position) on the photosensitive material. That is, the light beam corresponding to the outside of the image area on the photosensitive material is reflected by the SOS mirror and
It is incident on the S sensor. At this time, the SOS sensor outputs a predetermined signal to the microcomputer. The microcomputer which inputs this signal controls the light emission time of the semiconductor laser based on the input signal so that the photosensitive material is exposed from the writing position in the main scanning direction on the photosensitive material.

[0004]

However, since the polygon mirror in the above-mentioned exposure apparatus rotates at a high speed, high-frequency vibration is generated. The high-frequency vibration of the polygon mirror and the natural vibration of the SOS mirror cause a beat, and the timing of the light beam reflected from the SOS mirror and incident on the SOS sensor is deviated, and the signal output when the SOS sensor receives the light beam. (Jitter) occurs in the output timing of the. Therefore, the main scanning start point (first exposure position on the photosensitive material) on the photosensitive material is displaced. If the initial exposure position is displaced, the multiple exposure effect of the photosensitive material causes density unevenness in the sub-scanning direction on the recorded image on the photosensitive material, which causes a problem that an image of proper image quality cannot be formed.

Further, the high frequency vibration of the polygon mirror and the S
The above-mentioned jitter periodically fluctuates due to the beat caused by the natural vibration of the OS mirror. Therefore, the information writing position on the photosensitive material is periodically displaced due to the periodic fluctuation of the jitter. If the writing position shifts periodically,
For example, if the amount of jitter is large, the pixel position is
When the amount of jitter is small, the pixel positions are aligned, and such drooping pixel positions and alignment of pixel positions also appear periodically. When the sagging of the pixel positions and the alignment of the pixel positions appear periodically in this manner, the image density when the pixel positions are aligned and the image density when the pixel positions are aligned are caused by the multiple exposure effect of the photosensitive material. It will be different. For this reason, the image density unevenness in the sub-scanning direction periodically occurs on the recorded image on the photosensitive material, and it is impossible to form an image of appropriate quality.

The present invention has been made in view of the above facts, and an exposure capable of forming an image of proper image quality by preventing the occurrence of image density unevenness in the sub-scanning direction in a recorded image of a photosensitive material. The purpose is to provide a device.

[0007]

The invention according to claim 1 for attaining the above object, comprises a light source for emitting a light beam,
Main scanning means for main scanning by deflecting the light beam emitted from the light source in the main scanning direction and vibrating at a frequency f _p , and an image of the light beam deflected by the main scanning means on a photosensitive material Image forming means, sub-scanning means for moving the light beam and the photosensitive material relative to each other so that the sub-scanning interval is L, and sub-scanning; A reflection means for reflecting a light beam corresponding to the outside of the image area, having a natural frequency of f _m , a signal output means for outputting a predetermined signal when the light beam reflected from the reflection means is incident, and based on the signal And a light source control means for controlling the light source so as to perform main scanning from a main scanning start point, which is generated on the photosensitive material by vibration of the main scanning means and natural vibration of the reflecting means. image The minimum value of the spatial frequency of the region where the light and shade of the image is visually recognized, which is obtained from the visual recognition curve that represents the relationship between the spatial frequency of the light and shade of the image and the density difference of the light and shade of the image.
1. α2 is the maximum value of the spatial frequency of the area where the shade of the image is visually recognized, which is obtained from the visual recognition curve, and α is the minimum value.
1, the frequency f _p and the sub-scanning interval C1 of the value determined by L, the maximum value [alpha] 2, the frequency f _p and the value determined by the sub-scanning interval L C2, when the integer is n, the following To meet the first condition or the second condition,
At least one of the frequency f _p , the natural frequency f _m, and the sub-scanning interval L is set. When the first condition _{n · f p -C1 <f m} <n · f p + C1 second condition _{f m ≧ n · f p,} n · f p + C2 < when _{f m f m <n · f} p _{, n · f p -C2> f} m

According to a second aspect of the invention, a light beam is emitted.
Main light source and a light beam emitted from the light source
The main scanning is performed by deflecting in the opposite direction and the frequency f_pso
Oscillating main scanning means, and deflected by the main scanning means
Image forming means for forming a focused light beam on the photosensitive material, and sub-scanning
The light beam and the photosensitive material are arranged so that the distance becomes L.
The sub-scanning means for relatively moving and sub-scanning, and the main running
Outside the image area on the light-sensitive material, which is deflected by the inspection means.
The natural frequency for reflecting the light beam corresponding to _mReflection of
Means and the light beam reflected from the reflecting means
When the signal output means for outputting a predetermined signal,
Based on the main scanning starting point based on the main light source
And an exposure device for controlling the light source.
And n is an integer, and the main scanning is obtained from the following equation (3).
Sensation caused by the vibration of the means and the natural vibration of the reflecting means
The spatial frequency A of the light and shade of the image on the optical material is
The photosensitive material is affected by the step frequency and the natural vibration of the reflecting means.
Spatial frequency of light and shade of an image and the light and shade of the image
The image obtained from the visual curve showing the relationship with the density difference of
It is smaller than the minimum value of the spatial frequency in the area where the image density is visible.
To obtain a minimum value, or obtained from the visual recognition curve
From the maximum value of the frequency of the area where the light and shade of the image is visually recognized
The frequency f is set to a large value._p, The natural vibration
Number f_mAnd at least one of the scanning intervals L in the sub-scanning direction
It is set.

A = | f _m −n · f _p | / (L · f _p ) ... (3)

According to a third aspect of the present invention, a light source that emits a light beam, and a main scanning unit that deflects the light beam emitted from the light source in the main scanning direction to perform main scanning and vibrate at a frequency f _p An image forming means for forming an image of the light beam deflected by the main scanning means on the photosensitive material, and the light beam and the photosensitive material are relatively moved so that the sub-scanning interval becomes L. A sub-scanning unit for scanning, and a signal output unit having a natural frequency f _m for outputting a predetermined signal when a light beam deflected by the main scanning unit and corresponding to a light beam outside the image area on the photosensitive material is incident, An exposure apparatus comprising: a light source control unit that controls the light source so as to perform main scanning from a main scanning start point based on the signal, wherein the vibration of the main scanning unit and the natural vibration of the signal output unit On the photosensitive material The minimum value of the spatial frequency of the region where the light and shade of the image is visually recognized, which is obtained from the visual recognition curve that represents the relationship between the spatial frequency of the light and shade of the generated image and the density difference of the light and shade of the image, is obtained from the visual recognition curve. The maximum value of the spatial frequency of the area where the light and shade of the image is visually recognized is α2, the minimum value α1, the frequency f _p, and the value determined by the sub-scanning interval L is C1, the maximum value α2, and the frequency f _p.
And C2 is a value determined by the sub-scanning interval L and n is an integer, the frequency f _p , the natural frequency f _m, and the sub-frequency are satisfied so as to satisfy the following first condition or second condition. At least one of the scanning intervals L is set. When the first condition _{n · f p -C1 <f m} <n · f p + C1 second condition _{f m ≧ n · f p,} n · f p + C2 < when _{f m f m <n · f} p _{, n · f p -C2> f} m

According to a fourth aspect of the present invention, a light source that emits a light beam, and a main scanning unit that deflects the light beam emitted from the light source in the main scanning direction to perform main scanning and vibrate at a frequency f _p An image forming means for forming an image of the light beam deflected by the main scanning means on the photosensitive material, and the light beam and the photosensitive material are relatively moved so that the sub-scanning interval becomes L. A sub-scanning unit for scanning, and a signal output unit having a natural frequency f _m for outputting a predetermined signal when a light beam deflected by the main scanning unit and corresponding to a light beam outside the image area on the photosensitive material is incident, An exposure apparatus comprising: a light source control unit that controls the light source so as to perform main scanning from a main scanning start point based on the signal, wherein the main value obtained from the following equation (4), where n is an integer: Vibration of scanning means and signal output The spatial frequency A of the light and shade of the image on the photosensitive material caused by the natural vibration of the means is the spatial frequency of the light and shade of the image generated on the light sensitive material by the frequency of the main scanning means and the natural vibration of the signal output means, and the spatial frequency of the image. The density of the image obtained from the visual recognition curve showing the relationship with the density difference of the density is smaller than the minimum value of the spatial frequency of the visible region, or the density of the image obtained from the visual recognition curve. At least one of the frequency f _p , the natural frequency f _m, and the scanning interval L in the sub-scanning direction is set so as to have a value larger than the maximum value of the frequency of the region where is visible.

A = | f _m −n · f _p | / (L · f _p ) ... (4)

[0013]

According to the first aspect of the invention, the main scanning means vibrating at the frequency f _p performs the main scanning by deflecting the light beam emitted from the light source in the main scanning direction. Note that, for example,
The main scanning means may include a mirror that reciprocates at the frequency f _p .

Further, the sub-scanning means relatively moves the light beam and the photosensitive material so that the sub-scanning interval becomes L. Reflecting means having a natural frequency of f _m reflects the light beam deflected by the main scanning means and corresponding to outside the image area on the photosensitive material. The signal output means outputs a predetermined signal when the light beam reflected by the reflecting means is incident. The light source control means controls the light source based on the signal so that the main scanning starts from the main scanning start point. The image forming means forms an image of the light beam deflected by the deflecting means on the photosensitive material.

Then, it is obtained from a visual recognition curve showing the relationship between the spatial frequency of the image density and the density difference of the image density produced on the photosensitive material by the vibration of the main scanning means and the natural vibration of the reflection detecting means. The minimum value of the spatial frequency of the region where the light and shade of the image is visually recognized is α1, the maximum value of the spatial frequency of the region where the light and shade of the image is visually recognized obtained from the visual recognition curve is α2, the minimum value α1, and the sub-scanning interval L. And a value determined by the frequency f _p is C1, a maximum value α2, a sub-scanning interval L and a value determined by the frequency f _p are C2,
When an integer is n, at least one of the frequency f _p , the natural frequency f _m, and the sub-scanning interval L is set so as to satisfy the first condition or the second condition. .

Here, the distance that the main scanning line advances in the sub-scanning direction per unit time is L · f _p .

Further, the main scanning means, for example, the frequency f _p caused by reciprocating motion at a frequency f _p, the natural frequency of the reflecting means when the f _m, the vibration and the said main scanning means The beat frequency Δf generated by the natural vibration of the reflecting means is obtained from the following equation (5).

Δf = | f _m −n · f _p | (5) Therefore, the spatial frequency, which is the number of times the image density appears per unit length generated on the photosensitive material by this beat, is defined as f _s . Then, the following relational expression (6) is established.

[0019]

[Equation 1]

Here, as shown in FIG. 6, the relationship between the spatial frequency of the light and shade of the image generated on the photosensitive material by the vibration of the main scanning means and the natural vibration of the reflecting means and the density difference of the light and shade of the image is shown. From the visual recognition curve shown, the density difference is d
In this case, when the spatial frequency f _s is α1 or more and α2 or less, image unevenness is recognized on the photosensitive material. That is, in the region R1 shown in FIG. 6, since the spatial frequency of the density of the image generated on the photosensitive material is small, it cannot be recognized unless the density difference of the density of the image is large, and the region R3
Then, since the spatial frequency of the light and shade of the image generated on the photosensitive material is large, it cannot be recognized even in this case unless the difference in the density of the light and shade of the image is large. However, in the region R2, the spatial frequency of the light and shade of the image generated on the photosensitive material is relatively recognizable with the density difference of the light and shade of the image. Therefore, the spatial frequency f _s is smaller than the spatial frequency of the boundary between the regions R1 and R2 (the minimum spatial frequency of the region R2 in which the shade of the image obtained from the visual recognition curve is visually recognized) α1, or When the spatial frequency f _s is larger than the spatial frequency of the boundary between the regions R2 and R3 (the maximum spatial frequency of the region R2 in which the shade of the image obtained from the visual recognition curve is visually recognized) α2, Image unevenness cannot be recognized. Therefore, the relational expressions of the following expressions (7) and (8) are established from the expressions (5) and (6).

[0021]

[Equation 2]

[0022]

[Equation 3]

When the above formula (7) is modified, the following formula (9) is modified. When the above formula (8) is modified, if f _m ≧ n · f _p , the following formula (10) and f _m <n · In the case of f _p , the following equation (11) is obtained.

[0024] _{n · f p -α1 · L ·} f p <f m <n · f p + α1 · L · f p ··· (9)

N · f _p + α2 · L · f _p <f _m (10)

N · f _p −α2 · L · f _p > f _m (11) Therefore, in the invention according to claim 1, the first condition (corresponding to formula (9)) or the second condition is satisfied. At least one of the frequency f _p , the natural frequency f _m, and the sub-scanning interval L is set so as to satisfy the condition (corresponding to the formulas (10) and (11)). Therefore, it is possible to prevent a beat from occurring between the vibration of the main scanning unit and the natural vibration of the reflecting unit, and thereby to prevent the fluctuation of the reflecting unit due to the vibration of the main scanning unit. Then, the signal output means appropriately outputs the predetermined signal to the light source control means. Therefore, the exposure is surely started from the main scanning start point on the photosensitive material.

According to the second aspect of the invention, on the photosensitive material generated by the vibration of the main scanning means and the natural vibration of the reflecting means obtained from the above formula (1) (corresponding to the above formula (6)). A visual curve showing the relationship between the spatial frequency A of the light and shade of the image and the spatial difference of the density of the light and shade of the image generated on the photosensitive material by the vibration of the main scanning means and the natural vibration of the reflecting means. So that the density of the image obtained from the above is smaller than the minimum value (corresponding to α1) of the spatial frequency of the visible region R2 (see FIG. 6), or the density of the image obtained from the viewing curve. At least one of the frequency f _p , the natural frequency f _m, and the sub-scanning interval L is set so that the value becomes larger than the maximum value (corresponding to α2) of the spatial frequency of the visible region R2. ing.

Therefore, the above expression (7) or the above expression (8) is satisfied, and image unevenness is not recognized in the image on the photosensitive material.

Here, in the case where the above-mentioned main scanning means is constituted by including the polygon mirror of the reflecting surface n _p rotating at the rotation speed f _p , the distance that the main scanning line advances in the sub scanning direction per unit time is , L · n _p · f _p . Therefore, the denominator of the above equation (6) is L · n _p · f _p . Therefore, the denominator of the above equations (7) and (8) is also L · n _p · f _p . From the above, the above equations (9) to (11) become the following equations (12) to (14).

[0030] _{n · f p -α1 · L ·} n p · f p <f m <n · f p + α1 · L · n p · f p ·· · (12)

N · f _p + α2 · L · n _p · f _p <f _m (13)

N · f _p −α2 · L · n _p · f _p > f _m (14) Further, like the invention of claim 3, the signal output means of the invention of claim 1 is replaced. A predetermined signal is output when the light beam reflected by the reflecting means and the reflecting means having a natural frequency f _m for deflecting the light beam deflected by the main scanning means and corresponding to the outside of the image area on the photosensitive material is incident. You may make it provide the signal output means to operate.

In this case, the image obtained from the visual recognition curve showing the relationship between the spatial frequency of the image density and the density difference of the image density caused on the photosensitive material by the vibration of the main scanning means and the natural vibration of the reflecting means. When the minimum value of the spatial frequency of the area where the light and shade are visually recognized is α1 and the maximum value of the spatial frequency of the area where the light and shade of the image is visually recognized obtained from the visual recognition curve is α2, the first condition or the second condition described above is used. At least one of the frequency f _p , the natural frequency f _m, and the sub-scanning interval L is set so as to satisfy the condition of.

As described above, in the invention described in claim 3, as in the invention described in claim 1, the first condition (equation (9)) is satisfied.
Or the second condition (equation (10) and equation (1
1) corresponding to 1), at least 1 of the frequency f _p , the natural frequency f _m, and the sub-scanning interval L.
One is set. Therefore, it is possible to prevent a beat from occurring between the vibration of the main scanning unit and the natural vibration of the reflecting unit, and thereby to prevent the fluctuation of the reflecting unit due to the vibration of the main scanning unit. Then, the signal output means appropriately outputs the predetermined signal to the light source control means. Therefore, the exposure is surely started from the main scanning start point on the photosensitive material.

Similarly, as in the fourth aspect of the invention, instead of the signal output means of the third aspect of the invention, a light beam deflected by the main scanning means and corresponding to the outside of the image area on the photosensitive material is used. A reflecting means having a natural frequency f _m for reflecting and a signal outputting means for outputting a predetermined signal when the light beam reflected from the reflecting means is incident may be provided.

In this case, the spatial frequency A obtained from the above equation (2) (corresponding to the above equation (6)) is generated on the photosensitive material by the frequency of the main scanning means and the natural vibration of the reflecting means. The density of the image obtained from the visual recognition curve that represents the relationship between the spatial frequency of the grayscale of the image and the density difference of the grayscale of the image is smaller than the minimum value of the spatial frequency of the visible region, or At least one of the frequency f _p , the natural frequency f _m, and the scanning interval L in the sub-scanning direction is set so as to have a value larger than the maximum value of the frequency.

Therefore, the above expression (7) or the above expression (8) is satisfied, and image unevenness is not recognized in the image on the photosensitive material.

[0038]

Embodiments of the present invention will now be described 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 device 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 a machine base 12 of the image recording apparatus 10, and a photosensitive material 16 is wound into a roll and accommodated therein. The photosensitive material 16 is wound so that the photosensitive (exposure) surface faces the lower side of the apparatus.

The photosensitive material magazine 14 is provided with marks (for example, marks, notches, protrusions, etc.) according to the type of the photosensitive material 16 housed therein, and the loading section 10A.
A sensitive material detection sensor 202 that detects this mark is attached to the. The sensitive material detection sensor 202 is connected to the control device 206, and the presence / absence of loading of the sensitive material magazine 14 and the type and lot of the photosensitive material 16 accommodated therein can be determined by a signal from the sensitive material detection sensor 202. .

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 photosensitive 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 photosensitive material 16 cut to a predetermined length is sent to the exposure section 22. Can be transported.

The exposure section 22 is located between the transport rollers 23 and 24, and the photosensitive material 16 passes through between these transport rollers as an exposure section (exposure point). Sub-scan).

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 258C, 258 as a light source of C (cyan), M (magenta) and Y (yellow).
M and 258Y are provided. Semiconductor laser 258
Collimator lenses 260 that convert the light beams emitted from the semiconductor lasers 258C, 258M, and 258Y into parallel rays are provided near the exit sides of C, 258M, and 258Y, respectively. The respective light beams converted into parallel rays by the collimator lens 260 are separated by the cylindrical lens 263.
Incident on the reflection mirror 262 via
The light beams are reflected, are combined, and are incident on a polygon mirror 264 as a main scanning unit. The cylindrical lens 263 has a role of correcting the surface tilt of the polygon mirror 264. Further, the polygon mirror 264 has six reflection surfaces _np (six polygon mirrors 268) for reflecting the incident light beam.

Further, the polygon mirror 264 is rotated at a high speed around the axis 266, and has a role of continuously changing and deflecting the incident angle of the light beam to the polygon mirror 268 (main scanning). In this embodiment, the polygon mirror 26
The rotation speed of No. 4 is 125 [rps].

The light beam main-scanned by the polygon mirror 264 has a concave plano lens 270a and a plano-convex lens 270.
It is reflected by the reflection mirrors 272 and 274 through the image forming optical system 270 as an image forming means including the Fθ lens configured by b and the concave and convex lens 270c, and reaches the exposure unit 22. The reflection mirror 274 is inclined at a predetermined angle so that the light beam reflected from the reflection mirror 272 is reflected vertically downward.

An SOS (Start Of Scan) mirror 275 as a reflection means is provided on the side of the reflection mirror 274, and the light beam reflected by the polygon mirror 264 is first irradiated. The SOS mirror 275 reflects the first light beam (light beam corresponding to the vicinity of the main scanning start point) irradiated, and SO as a signal output means.
It is adapted to enter the S sensor 276. And
The SOS sensor 276 outputs a predetermined signal when the light beam is incident from the SOS mirror 275. The signal output from the SOS sensor 276 is applied as a start signal of an image signal for one main scan, and the main scan start timings are synchronized.

In the exposure section 22, the main scanning of the light beam is repeated while the photosensitive material 16 is being sub-scanned so that one image is recorded.

The exposure amount is controlled by each semiconductor laser 258.
This is performed by changing the pulse width of the pulse signals output from C, 258M and 258Y (pulse width modulation). 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.

Here, the vibration of the polygon mirror 264 and the S
In this embodiment, the natural frequency f _m of the SOS mirror 275 is set as follows so that a beat is generated due to the natural vibration of the OS mirror 275 and the image unevenness in the sub-scanning direction is not recognized on the recorded image of the photosensitive material 16. Is set to.

That is, the polygon mirror 264 is 125
It is rotating at a high speed at a rotation speed f _p of [rps]. Therefore, the polygon mirror 264 causes a vibration of 125 [Hz]. Further, the sub-scanning interval L is set to 1.6 × 10 ^-2
[Mm] and the image density difference d of the image unevenness is 0.02, α1 is 0.1 [cycles / m as shown in FIG.
m] and α2 are 4 [cycles / mm].

Therefore, from equations (12) to (14),
If the natural frequency f _m is within the range of the following expression (15) or the following expression (16) and the following expression (17), image unevenness cannot be recognized on the recorded image on the photosensitive material.

[0054] _{125n-1.2 <f m <1.2} + 125n ··· (15)

125n + 48 <f _m , where f _m ≧ n · f _p (16)

125n−48> f _m , where f _m <n · f _p (17) That is, the above equation (15) or the above equations (16) and (17)
Therefore, unless the natural frequency f _m of the SOS mirror 275 becomes a value in the vicinity of a value that is an integral multiple of the rotation speed f _p of the polygon mirror 264, image unevenness is not recognized on the recorded image on the photosensitive material.

Here, when the integer n is 6, the above equation (1
5) to the above equation (17), the natural frequency f _m of the SOS mirror 275 is calculated from the above equation (15) to 748.8 [Hz].
The value is larger and smaller than 751.2 [Hz], or larger than 798 [Hz] from the above equation (16), or smaller than 702 from the above equation (17). When the integer n is 7, the natural frequency f _m of the SOS mirror 275 is larger than 873.8 [Hz] from the above equation (15) from the above equation (15) to the above equation (17) and is 876. The value is smaller than 2 [Hz], or larger than 923 [Hz] from the above equation (16), or smaller than 827 [Hz] from the above equation (17). Therefore, in the present embodiment, the natural frequency f _{m is} set to a value larger than 798 [Hz] and smaller than 827 [Hz].
The material and shape of the SOS mirror 275 are determined so that

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 photosensitive material 16 that has risen up the side of the photosensitive material magazine 14 and has been exposed in the exposure unit 22 is once fed to the switchback unit 40, and then is reversely rotated by the transport roller 26, whereby the exposure unit 2 is exposed.
It is configured to be fed to the water application unit 62 via a transportation path provided below the No. 2. A plurality of pipes are connected to the water application section 62 so that water can be supplied.

The heat development transfer section 10 is provided on the side of the water application section 62.
4 is arranged so that the photosensitive material 16 coated with water is fed.

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.

The receiving material magazine 14 has a mark (for example, a mark corresponding to the type of the image receiving material 108 accommodated therein).
(Marks, notches, protrusions, etc.) are provided in the loading section 10.
A material receiving sensor 208 for detecting the mark is attached to B. This receiving material detection sensor 208 is connected to the control device 206, and this receiving material detection sensor 208
It is possible to determine whether or not the receiving material magazine 14 is loaded, and the type and lot of the image receiving material 108 accommodated in the receiving material magazine 14 from the signal from the.

A nip roller 110 is arranged in the vicinity of the image receiving material take-out port of the material receiving magazine 106, and 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 170 is provided at the side of 4. The image receiving material transport unit 170 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 photosensitive material 16 conveyed to the heat development transfer section 104 is sent between the bonding roller 120 and the heating drum 116, and the image receiving material 108 is the photosensitive material 1.
In synchronism with the conveyance of 6, the photosensitive material 16 is fed between the laminating roller 120 and the heating drum 116 in a state of being preceded by a predetermined length so as to be superposed.

Inside the heating drum 116, a pair of halogen lamps 132A and 132B are arranged 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 on the downstream side of the endless pressure contact belt 118 in the material supply direction.
Are 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 photosensitive material 16 peeled by the peeling claw 154 is wound around the bending guide roller 142 and 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. 5, 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. The input / output port 248 has an image signal S (for example, a video signal or the like) which is a basis of an image to be recorded.
Is entered. Further, signal lines 252 and 254 to the photosensitive material conveying system and the image receiving material conveying system are connected to the input / output port 248 to control the driving of each driving unit and the conveyance of the photosensitive material or the image receiving material. There is. Further, the I / O port 248 is connected to the SOS sensor 27.
6 is connected. Further, the input / output port 248 has current control units 257Y, 25 for controlling the emission timing and emission intensity of the semiconductor lasers 258Y, 258M, 258C.
7M and 257C are installed.

Next, the operation of this embodiment will be described. First, when a processing start instruction is given, the nap roller 18 is operated with the photosensitive material magazine 14 set, and the photosensitive material 16 is pulled out by the nap roller 18. When the photosensitive material 16 is pulled out by a predetermined length, the cutter 20 operates and the photosensitive material 16 is cut into a predetermined length.

After the operation of the cutter 20, the photosensitive material 16 is
The sheet is inverted and conveyed to the exposure section 22 with its photosensitive (exposure) surface facing upward. At the same time when the photosensitive material 16 is conveyed, the exposure device 38 operates to scan and expose the photosensitive material 16 located in the exposure section 22. That is, the semiconductor laser 25
The light beams emitted from the 8Y, 258M, and 258C and emitted are incident on the collimator lens 260. 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 axes of the respective light beams are focused by the polygon mirror 264, and the respective light beams are combined and incident on the polygon mirror 268 of the polygon mirror 264.

The polygon mirror 264 is provided with six reflection mirrors (polyhedral mirrors) 268, and a light beam is incident on each surface at a frequency of 750 [Hz]. The light beam is deflected in the main scanning direction by the rotation of the polygon mirror 264. While being deflected in the main scanning direction, the light beam is reflected by the concave plano lens 27.
0a, a plano-convex lens 270b, and a concave-convex lens 270c, and is incident on an Fθ lens having a predetermined imaging relationship,
The reflection mirror 272 reflects the light vertically upward, and the reflection mirror 274 reflects the light vertically downward to form an image on the photosensitive material 16 to expose the photosensitive material 16.

Here, the light beam deflected by the polygon mirror 264 is first irradiated on the SOS mirror 275 and reflected, and then enters the SOS sensor 276. And SO
The S sensor 276 outputs a predetermined signal when the light beam reflected by the SOS mirror 275 is incident. The signal output from the SOS sensor 276 is applied as a start signal of the image signal for one main scanning, and each main scanning start time is synchronized. As a result, the photosensitive material 16 starts to be exposed from a predetermined position (writing position) of the photosensitive material 16 in the main scanning direction. 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 so that the photosensitive material 16 is mainly irradiated. The photosensitive material 16 is exposed while scanning. In this way, the exposure unit 2
In 2, the main scanning of the light beam is repeated while the photosensitive material 16 is sub-scanned to expose the photosensitive material 16 to 1
Images are recorded.

After the exposure is started, after the exposed photosensitive material 16 is once sent to the switchback section 40,
It is sent to the water application section 62 by the reverse rotation of the carrying roller 26.

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

The photosensitive material 16 coated with water as the image forming solvent in the water coating section 62 is squeeze roller 6
It is sent to the heat developing and transferring section 104 by 8.

On the other hand, as the scanning exposure of the photosensitive material 16 is started, the image receiving material 108 is also pulled out from the material receiving magazine 106 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 photosensitive material 16 has been fed by the squeeze roller 68 between the outer periphery of the heating drum 116 and the bonding roller 120, the conveyance of the image receiving material 108 is restarted. The heating drum 11 is fed to the laminating roller 120 as well.
6 is activated.

In this case, the guide plate 122 is arranged between the laminating roller 120 and the squeeze roller 68 of the water applying section 62, and the photosensitive material 16 sent from the squeeze roller 68 is surely bonded to the laminating roller 120. Be guided to.

The photosensitive material 16 and the image receiving material 108 superposed by the laminating roller 120 are kept in the superposed state with the heating drum 116 and the endless press belt 11.
It is sandwiched between the heating drum 116 and the heating drum 116, and approximately 2/3 of the circumference (between the winding roller 134 and the winding roller 140).
Be transported to. As a result, the photosensitive 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.

After that, when the photosensitive material 16 and the image receiving material 108 are nipped and conveyed and reach the lower portion of the heating drum 116, the peeling claw 154 is moved by the cam 130 and the image receiving material 1
08, the peeling claw 154 engages with the leading end of the photosensitive material 16 that is conveyed by a predetermined length, and peels the leading end of the photosensitive material 16 from the outer periphery of the heating drum 116. Further, the pinch roller 157 presses the photosensitive material 16 by the returning movement of the peeling claw 154, whereby the photosensitive material 16 is wound around the bending guide roller 142 while being pressed by the pinch roller 157, and is moved downward to be discarded photosensitive material. It is accumulated in the storage box 178.

On the other hand, the heating drum 1 separated from the photosensitive material 16
The image receiving material 108 that moves while being in close contact with 16.
Is sent to the peeling roller 174 and peeled.

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.

As described above, in the present embodiment, when the image density difference d is 0.02, α obtained from the visual recognition curve is obtained.
1 is 0.1 [cycles / mm], α2 is 4 [cycles / m]
m], it is necessary that the spatial frequency f _{s at which} light and shade due to image unevenness on the photosensitive material appears is smaller than 0.1 [cycles / mm] or larger than 4 [cycles / mm]. is there. Therefore, in the present embodiment, α2 (= 4) is used as a reference, and the natural frequency f _m of the SOS mirror is calculated by the above equation (1
S is greater than 798 [Hz] obtained from (16) corresponding to 3) and smaller than 827 [Hz] obtained from the above equation (17) corresponding to the above equation (14).
The material and shape of the OS mirror are set. This allows
The natural frequency f _m of the SOS mirror is set so as not to be in the vicinity of 6 times and 7 times the frequency f _p of the polygon mirror. Therefore, it is possible to prevent the SOS mirror from fluctuating due to the vibration of the polygon mirror.
The S sensor appropriately outputs a predetermined signal to the control device.
Therefore, the light beam is surely emitted from a predetermined position on the photosensitive material. Therefore, the pixel positions are aligned and a proper image is formed.

In the embodiment described above, α2 obtained from the visual recognition curve is used as a reference, but the present invention is not limited to this, and α1 (equation (15) corresponding to equation (12)) may be used as a reference. . Further, although the image density difference d is set to 0.02, it is not limited to this and may be another value as shown in FIG.

Further, in the above-mentioned embodiment, the natural frequency f _m of the SOS mirror is not set to values near 6 times and 7 times the frequency f _p of the polygon mirror, but the present invention is not limited to this. Alternatively, it may be another integer multiple.

Although the SOS sensor is adapted to reflect the light beam in the vicinity of the main scanning start point on the photosensitive material, if it is outside the image area on the photosensitive material, it may be near the main scanning end point on the photosensitive material. Further, the light beam on the photosensitive material outside the image area or on the outside of the photosensitive material may be reflected.

Further, the natural frequency f _m of the SOS mirror is
Equation (1) corresponding to equations (12), (13) and (14)
5), (16) and (17) are satisfied, but the present invention is not limited to this, and the frequency f _p (that is, the rotation speed f _p ) of the polygon mirror and the sub-scanning interval L are expressed by the formula ( Equations (1) corresponding to (12), (13) and (14)
5), (16) and (17) may be satisfied, also, the frequency f _p of the natural frequency f _m polygon mirror SOS mirror (i.e., the rotational speed f _p) and the sub-scanning interval L By all, equations (12), (13) and (1
Equations (15), (16) and (17) corresponding to 4) may be satisfied.

Further, although the SOS mirror and the SOS sensor are provided, the present invention is not limited to this, and the light beam reflected by the polygon mirror having only the SOS sensor may first enter the SOS sensor. in this case,
Equations (15), (16) and (17) corresponding to equations (12), (13) and (14) for the natural frequency of the SOS sensor
To be satisfied.

[0094] In the embodiment described above, causes the frequency f _p (i.e., rotates at a rotational speed f _p) has been described an example of using a polygon mirror, not intended to this limitation, the frequency f _p A reciprocating mirror, for example, a resonant scanner or a galvanometer mirror may be used.

[0095]

As described above, according to the inventions of claims 1 and 3, the frequency f _p of the main scanning means and the signal are satisfied so that the following first condition or second condition is satisfied. Since at least one of the natural frequency f _m of the output means or the reflecting means and the sub-scanning interval L is set, a beat occurs between the vibration of the main scanning means and the natural vibration of the reflecting means. Therefore, it is possible to prevent the reflection means from being fluctuated due to the vibration of the main scanning means, and the signal output means appropriately outputs a predetermined signal to the light source control means, so that the photosensitive material is not affected. It is possible to reliably start the exposure from the main scanning start point of 1. When the first condition _{n · f p -C1 <f m} <n · f p + C1 second condition _{f m ≧ n · f p,} n · f p + C2 < when _{f m f m <n · f} p _{, n · f p -C2> f} m

According to the second and fourth aspects of the invention, the image on the photosensitive material generated by the vibration of the main scanning means and the natural vibration of the reflecting means or the signal outputting means obtained from the following equation (18) The spatial frequency A of the grayscale represents the relationship between the frequency of the grayscale of the image generated on the photosensitive material by the vibration of the main scanning means and the natural vibration of the reflecting means or the signal output means and the density difference of the grayscale of the image. The density of the image obtained from the visual recognition curve is smaller than the minimum value of the spatial frequency of the visible region, or the maximum of the spatial frequency of the region where the dark and light of the image obtained from the visual recognition curve is visually recognized. Since at least one of the frequency f _p , the natural frequency f _m, and the sub-scanning interval L is set so that the value becomes larger than the value, the above expression (7) or the above expression (8) is satisfied. What to do Becomes, the image unevenness can be prevented from being recognized by the images on the photosensitive material, an effect that.

A = | f _m −n · f _p | / (L · f _p ) ... (18)

[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 a control block diagram.

FIG. 6 is a diagram showing a relationship between an image density difference of light and shade of an image based on image unevenness and a spatial frequency of light and shade of an image based on image unevenness appearing on a photosensitive material.

[Explanation of symbols]

10 Image recording device 16 Photosensitive material 38 Exposure equipment 62 Water application section 104 heat development transfer section 108 heating drum 118 Endless pressure welding belt 258Y, 258M, 258C Semiconductor laser 264 polygon mirror 275 SOS mirror 276 SOS sensor

Claims (4)

(57) [Claims] 1. A light source that emits a light beam, a main scanning unit that performs main scanning by deflecting the light beam emitted from the light source in the main scanning direction and that vibrates at a frequency f _p , and the main scanning unit. An image forming means for forming an image of the light beam deflected by the light-sensitive material on the photosensitive material; and a sub-scanning means for moving the light beam and the photosensitive material relative to each other so that the sub-scanning interval becomes L. , The natural frequency for reflecting the light beam deflected by the main scanning means and corresponding to the outside of the image area on the photosensitive material is f
_m reflection means, signal output means for outputting a predetermined signal when the light beam reflected from the reflection means is incident, and the light source is controlled so as to perform main scanning from the main scanning start point based on the signal. An exposure apparatus comprising: a light source control means, wherein the relationship between the spatial frequency of the image density and the density difference of the image density produced on the photosensitive material by the vibration of the main scanning means and the natural vibration of the reflecting means. The minimum value of the spatial frequency of the region where the shade of the image is visually recognized, which is obtained from the visual recognition curve, is α1, and the maximum value of the spatial frequency of the region where the shade of the image is visually recognized, which is obtained from the visual curve is α2, A value determined by the minimum value α1, the frequency f _p and the sub-scanning interval L is C1, a maximum value α2, a value determined by the frequency f _p and the sub-scanning interval L is C2, and an integer is n.
Then, at least one of the frequency f _p , the natural frequency f _m and the sub-scanning interval L is set so that the following first condition or second condition is satisfied. When the first condition _{n · f p -C1 <f m} <n · f p + C1 second condition _{f m ≧ n · f p,} n · f p + C2 < when _{f m f m <n · f} p _{, n · f p -C2> f} m 2. A light source that emits a light beam, a main scanning unit that deflects the light beam emitted from the light source in the main scanning direction to perform main scanning, and vibrates at a frequency f _p , and the main scanning unit. An image forming means for forming an image of the light beam deflected by the light-sensitive material on the photosensitive material; and a sub-scanning means for relatively scanning the light beam and the photosensitive material so that the sub-scanning interval becomes L. , The natural frequency for reflecting the light beam deflected by the main scanning means and corresponding to the outside of the image area on the photosensitive material is f
_m reflection means, signal output means for outputting a predetermined signal when the light beam reflected from the reflection means is incident, and the light source is controlled so as to perform main scanning from the main scanning start point based on the signal. An exposure apparatus comprising: a light source control means, wherein n is an integer, and the density of an image on a photosensitive material caused by the vibration of the main scanning means and the natural vibration of the reflecting means, which is obtained from the following equation (1), The spatial frequency A is obtained from a visual recognition curve showing the relationship between the spatial frequency of the image density and the density difference of the image density produced on the photosensitive material due to the frequency of the main scanning means and the natural vibration of the reflection means. A value that is smaller than the minimum value of the spatial frequency of the region where the shade of the image is viewed, or a value that is larger than the maximum value of the frequency of the region where the shade of the image obtained from the viewing curve is viewed. So that, the frequency f _p, the natural frequency f
An exposure apparatus in which at least one of _m and a scanning interval L in the sub-scanning direction is set. _{A = | f m -n · f} p | / (L · f p) ··· (1) 3. A light source that emits a light beam, a main scanning unit that deflects the light beam emitted from the light source in the main scanning direction to perform main scanning, and vibrates at a frequency f _p , and the main scanning unit. An image forming means for forming an image of the light beam deflected by the light-sensitive material on the photosensitive material; and a sub-scanning means for moving the light beam and the photosensitive material relative to each other so that the sub-scanning interval becomes L. A signal output unit having a natural frequency f _m for outputting a predetermined signal when a light beam deflected by the main scanning unit and corresponding to a region outside the image area on the photosensitive material is incident; An exposure apparatus comprising: a light source control unit that controls the light source so that main scanning is performed from a scanning start point, wherein an image generated on a photosensitive material by vibration of the main scanning unit and natural vibration of the signal output unit. Shading The minimum value of the spatial frequency of the region where the shade of the image is visually recognized, which is obtained from the visual recognition curve showing the relationship between the spatial frequency and the density difference of the grayscale of the image, is α1, and the shading of the image obtained from the visual recognition curve is The maximum value of the spatial frequency of the visible region is α2, the minimum value α1, the frequency f _p, and the value determined by the sub-scanning interval L is C1, the maximum value α2, and the frequency f.
_{When the} value determined by _p and the sub-scanning interval L is C2, and the integer is n, the frequency f _p , the natural frequency f _m, and the natural frequency f _m are satisfied so as to satisfy the following first condition or second condition. An exposure apparatus in which at least one of the sub-scanning intervals L is set. When the first condition _{n · f p -C1 <f m} <n · f p + C1 second condition _{f m ≧ n · f p,} n · f p + C2 < when _{f m f m <n · f} p _{, n · f p -C2> f} m 4. A light source that emits a light beam, a main scanning unit that performs main scanning by deflecting the light beam emitted from the light source in the main scanning direction and that vibrates at a frequency f _p , and the main scanning unit. An image forming means for forming an image of the light beam deflected by the light-sensitive material on the photosensitive material; and a sub-scanning means for moving the light beam and the photosensitive material relative to each other so that the sub-scanning interval becomes L. A signal output unit having a natural frequency f _m for outputting a predetermined signal when a light beam deflected by the main scanning unit and corresponding to a region outside the image area on the photosensitive material is incident; An exposure apparatus comprising: a light source control unit that controls the light source so as to perform main scanning from a scanning start point, wherein an integer is n, and vibration of the main scanning unit obtained from the following equation (2) and the vibration For the natural vibration of the signal output means The spatial frequency A of the light and shade of the image on the light-sensitive material generated is the spatial frequency of the light and shade of the image and the density of the light and shade of the image generated on the light-sensitive material by the frequency of the main scanning means and the natural vibration of the signal output means. The density of the image obtained from the visual recognition curve showing the relationship with the difference is smaller than the minimum value of the spatial frequency of the visible region, or the density of the image obtained from the visual recognition curve is visually recognized. At least one of the frequency f _p , the natural frequency f _m, and the scanning interval L in the sub-scanning direction so that the frequency becomes larger than the maximum value of the frequency of the region.
An exposure device that sets one. _{A = | f m -n · f} p | / (L · f p) ··· (2)