JPH09121269A - Image recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent fog due to the unnecessary exposure of photosensitive material while photosensitive material is stopped after an image is recorded by providing a specified shutter means. SOLUTION: Between an optical modulator 15 and a cylindrical lens 16, a mechanical shutter means 20 is arranged at the location near the optical path of laser beam 10. This shutter means 20 is composed of a disk like shutter member 21 part of which is notched and a driving part 22 rotating this shutter member 21. The driving part 22 selectively sets the shutter member 21 to either one of the rotation location interrupting laser beam 10 and the rotation location not interrupting laser beam 10. Because the shutter member is in a closed state untill the next image recording is restarted after an image recording is terminated, faint laser beam 10 leaked from the optical modulator 15 is interrupted by this shutter member 21. As a result, the faint laser beam 10 does not reach photosensitive material 12 and does not generate fog in the material 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus for scanning a photosensitive material with a modulated light beam to record an image on the photosensitive material. The present invention relates to an image recording apparatus which prevents a photosensitive material from being unnecessarily exposed by a recording light beam until an image is recorded.

[0002]

2. Description of the Related Art Conventionally, there has been provided an optical scanning type image recording apparatus for recording an image on a photosensitive material by scanning a photosensitive material mainly and sub-scanned by a modulated light beam.

As one of the image recording apparatuses of this type, a recording light source for emitting a light beam, a main scanning means for main scanning the light beam on the photosensitive material, and a main scanning direction for the photosensitive material are substantially orthogonal to each other. That includes a sub-scanning unit that conveys the light beam emitted from the recording light source, and an optical modulator that modulates the light beam emitted from the recording light source based on an image signal. It is widely known that a photosensitive material is conveyed at a constant speed.

Such a sub-scanning image recording apparatus is
In particular, when a long photosensitive material is used and different images are recorded in the lengthwise direction, if the image signals carrying the respective images are supplied one after another without waiting time, the photosensitive material It is possible to record images one after another without stopping the transportation of the sheets. However, it is of course possible that the image signal carrying the image to be recorded next is not immediately supplied at the time when the recording of a certain image is completed. In such a case, generally, the photosensitive material is not wasted. Then, the conveyance of the photosensitive material is stopped.

[0005]

However, when the light beam is modulated by the external modulator as described above, if the light-sensitive material is kept in a stopped state, an image-recorded area of the light-sensitive material or its vicinity will be generated. Fog may occur. That is, when an external modulator is used, the recording light source is generally left on and the AOM (acousto-optical light modulator) is used.
The extinction ratio of the optical modulator such as is about 1: 1000, and it is impossible to completely block the light beam from the recording light source that was turned on and left, so the photosensitivity stopped at a fixed position. The material will be irradiated with the light beam. Although this light beam is weak, it is fogged on the photosensitive material because it continues to irradiate a certain portion of the photosensitive material while it is stopped.

Further, when stopping the transportation of the photosensitive material,
Even if control is performed to immediately stop the operation of the sub-scanning means at the time when the recording of a certain image is completed, the sub-scanning means may stop after a slight delay from the start of control due to inertia of the drive system. In this case, the photosensitive material is fed by a slight length and then stopped. In such a case, when the next image recording command is given, if the sub-scanning unit is re-activated and image recording is performed, the image is recorded between the front end of this image and the rear end of the previously recorded image. However, a blank portion of the photosensitive material is generated. Even when the sub-scanning unit is reactivated, it takes some time for the conveying speed of the photosensitive material to reach a predetermined constant speed, and during that time, image recording must be refrained. A blank space will be created.

The margins of the light-sensitive material thus produced are not so long one by one, but if the light-sensitive material is extremely long such as photographic print paper, the total of the margins is Will be extremely long.

Therefore, from the viewpoint of economically and effectively utilizing the light-sensitive material, in order to shorten the blank portion of the light-sensitive material as much as possible, one image is recorded on the light-sensitive material, and then the light-sensitive material is slightly lengthened. It is conceivable to feed in the direction opposite to the sub-scanning direction. That is, the operation of the sub-scanning unit is controlled by the control unit, and after one image is recorded on the photosensitive material, the sub-scanning unit is reversely driven so as to feed the photosensitive material in the direction opposite to the sub-scanning direction, and then stopped. Then, by receiving the recording command for the next image and driving the sub-scanning unit in the normal direction, it is possible to sufficiently shorten or eliminate the blank portion of the photosensitive material. In particular, the control means is arranged to stop the sub-scanning means when a part of the recorded image returns to the rear side in the sub-scanning direction from the position where the main scanning is performed after the sub-scanning means is driven in reverse. With this configuration, when the sub-scanning unit is restarted, it is possible to avoid the occurrence of a blank space by refraining from recording an image until the conveyance speed reaches a predetermined constant speed.

In the image recording apparatus having a structure in which the sub-scanning unit is controlled so as to be driven in the reverse direction as described above, the fog of the photosensitive material described above has already been recorded not only in the unexposed area of the photosensitive material but also in the image recording. It also occurs in the area, and the quality of the recorded image is significantly impaired.

On the other hand, the control means drives the sub-scanning means in the reverse direction, and then stops the sub-scanning means when the entire recorded image is on the front side in the sub-scanning direction from the position where the main scanning is performed. Even in the apparatus described above, the light beam continues to irradiate the portion on the rear side in the sub-scanning direction with respect to the area where the image is recorded on the photosensitive material. Even in such a case, if the light beam irradiation is continued for a long time, fogging may affect the image recording area of the photosensitive material or the area where the image recording is to be performed.

Further, even if the fog does not affect the image-recorded area of the photosensitive material or the area where the image is recorded, the margin portion of the photosensitive material is used as a white edge of the recorded image. In this case, this white edge becomes dirty due to fog.

The present invention has been made in view of the above circumstances, and provides an image recording apparatus which prevents fogging due to unnecessary exposure of a photosensitive material while the photosensitive material is stopped after recording one image. That is the purpose.

[0013]

A first image recording apparatus according to the present invention records one image on a recording light source, a main scanning unit, a sub-scanning unit, a light modulator, and a photosensitive material as described above. In the image recording apparatus having the control means for stopping the sub-scanning means after receiving the recording command for the next image and driving the sub-scanning means after recording one image, the next image is recorded. The shutter means is provided for preventing the light beam from the recording light source from entering the optical path of the light beam and reaching the photosensitive material for at least a part of the period until the light beam is read.

As the shutter means, specifically,
A mechanical shutter unit including a shutter member that moves in and out of the optical path of the light beam, or an optical shutter unit including a PLZT element, a liquid crystal element, an AOM, or the like can be used. Further, as the shutter means, in addition to a general type that blocks the light beam, a mirror type that greatly changes the traveling direction of the light beam can be used.

Further, as the recording light source, in addition to a gas laser, a solid-state laser or the like, a directly modifiable semiconductor laser (LD) or the like can be applied. This is because even such a light source capable of direct modulation may be modulated using an external optical modulator.

Further, in this image recording apparatus, the control means may control the sub-scanning means to rotate in reverse after the completion of recording one image and then stop the sub-scanning means. However, after reversely driving the sub-scanning means, control is performed to stop the sub-scanning means when part of the recorded image returns to the rear side in the sub-scanning direction from the position where main scanning is performed. You can also

The second image recording apparatus of the present invention records by controlling a recording light source which emits a light beam and which can be directly modulated, such as an LD, and a drive current applied to this recording light source, based on an image signal. The modulation means for directly modulating the light beam emitted from the light source, the main scanning means as described above, the sub-scanning means, and the sub-scanning means are stopped after one image is recorded on the photosensitive material to record the next image. An image recording apparatus provided with a control means for driving a sub-scanning means in response to a command, characterized in that the shutter means is provided.

The shutter means of the second image recording apparatus of the present invention also uses mechanical shutter means or optical shutter means composed of PLZT elements, liquid crystal elements, AOMs, etc., as in the first image recording apparatus. In addition to the general type that blocks the light beam, a mirror type that greatly changes the traveling direction of the light beam can also be used.

As for the control means, similarly to the first image recording apparatus, control for driving the sub-scanning means in reverse is performed, and a part of the recorded image is located on the rear side in the sub-scanning direction from the position where main scanning is performed. It is also possible to adopt a mode in which the control for stopping the sub-scanning unit is performed when returning. It should be noted that each aspect of the control means can be similarly applied to the image recording apparatus of each of the following inventions.

A third image recording apparatus of the present invention is the same recording light source as the first image recording apparatus of the present invention described above, a main scanning unit, a sub-scanning unit, an optical modulator, and a photosensitive member. The sub-scanning means is stopped after one image is recorded on the material,
In an image recording apparatus provided with a control means for driving the sub-scanning means in response to a recording instruction for the next image, at least a part of a period from the recording of one image to the recording of the next image. A light beam emission stopping means for stopping the driving of the recording light source to stop the generation of the light beam from the recording light source is further provided.

A gas laser is used as the recording light source,
In addition to a solid-state laser or the like, a directly modifiable LD or the like can also be applied.

The fourth image recording apparatus of the present invention is a recording light source which emits a light beam and which can be directly modulated, such as an LD.
The drive current applied to the recording light source is controlled based on the image signal to directly modulate the light beam emitted from the recording light source, the main scanning unit as described above, the sub-scanning unit, and the photosensitive material. An image recording apparatus comprising: a control unit that stops the sub-scanning unit after recording one image and receives a recording command for the next image to drive the sub-scanning unit.
Further, a light beam emission stopping means for stopping the driving of the recording light source and stopping the generation of the light beam from the recording light source for at least a part of the period from the recording of one image to the recording of the next image. It is characterized by having.

In the fourth image recording apparatus of the present invention, fog is prevented by stopping the emission of the light beam. Therefore, the light beam is actually re-emitted after the next image recording command is issued. In practice, it is desirable to use a recording light source that has a short rise time (response time). For example, in an image recording apparatus that records a color image using three color lasers of R (red), G (green), and B (blue), for example, R is LD and SHG (Se is used for G and B).
cond Harmonic Generation) is used. This SHG
Since the laser uses the second harmonic, it takes some time for the output of the light beam to stabilize. On the other hand, for R, since the light beam is directly output, there is no such rise instability. From this viewpoint, it is desirable to apply the third or fourth image recording apparatus of the present invention to R.

The light beam emission stopping means in the third or fourth image recording apparatus of the present invention may also serve as the modulating means. In this case, the existing constituent element (modulating means) is used as it is. By doing so, the configuration can be simplified.

[0025]

As described above, in the image recording apparatus of the present invention, the light beam from the recording light source is emitted from the recording light source by the shutter means for at least a part of the period from the recording of one image to the recording of the next image. Is blocked so that it does not reach the photosensitive material, or because the light beam emission stopping means stops the generation of the light beam and does not reach the photosensitive material. The material is not irradiated with the light beam for a long time, and the fog of the photosensitive material is prevented.

This effect is the same when the control means controls the sub-scanning means to rotate in the reverse direction.

Further, after the control means reversely drives the sub-scanning means, when a part of the recorded image returns to the rear side in the sub-scanning direction from the position where the main scanning is performed, the sub-scanning means is driven. When it is configured to stop, by providing the shutter means or by stopping the emission of the light beam, it is possible to prevent fog from occurring in the area of the photosensitive material where image recording has already been performed. Therefore, the effect of keeping the quality of the recorded image high becomes particularly remarkable.

However, even when the control means is not so configured, as described above, the light beam from the recording light source is blocked by the shutter means or the emission of the light beam is stopped, as described above. It is possible to prevent such a problem that the fog generated in the area where the image is not recorded spreads to the area where the image is recorded, or the white edge of the photosensitive material is stained by the fog.

Further, the above-mentioned mechanical shutter means can block the light beam completely, and is therefore particularly preferable in obtaining the above-mentioned effect. Some optical shutter means such as an AOM have an extinction ratio of about 1: 1000 and cannot completely block a light beam. However, such an optical shutter means is originally provided. With an external modulator with an extinction ratio of about 1: 1000, an extinction ratio of about 1: 106 can be achieved, so it can be said that fogging of the photosensitive material can be reliably prevented from a practical level of view. The prevention of unnecessary exposure can be ensured even by the image recording apparatus configured so that the recording light is not emitted from the recording light source by the beam emission stopping means.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an image recording apparatus of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the first image recording apparatus of the present invention. The image recording apparatus shown in the figure records, for example, a color continuous tone image, and a laser light source 11 as a recording light source that emits a light beam (laser beam) 10 and a long laser beam that deflects the laser beam 10. Polygon mirror for main scanning on photosensitive material 12 in the direction of arrow X
13, a pair of nip rollers 14 and 14 as sub-scanning means for conveying the photosensitive material 12 in the longitudinal direction Y, that is, a direction substantially orthogonal to the main scanning direction, and AO for modulating the laser beam 10.
A light modulator 15 such as M (acousto-optical light modulator), a cylindrical lens 16 for forming a linear image by the laser beam 10 on the mirror surface of the polygon mirror 13, and a laser beam 10 deflected by the polygon mirror 13 are exposed. Fθ lens 17 for converging at all main scanning positions on the material 12.

The polygon mirror 13 and the nip roller pair
14, 14 are driven by the control circuit 18. On the other hand, the optical modulator 15 is driven by a modulator driving circuit 19 which receives the image signal S, and modulates the laser beam 10 based on the image signal S.

Further, the optical modulator 15 and the cylindrical lens 16
A mechanical shutter means 20 is provided at a position close to the optical path of the laser beam 10 between and. The shutter means 20 includes, for example, a disk-shaped shutter member 21 with a part cut away, and a drive unit 22 for rotating the shutter member 21.
It consists of: The drive unit 22 connects the shutter member 21,
The rotation position that shuts off the laser beam 10 and the laser beam 10
Is selectively set to one of the rotational positions that does not block.

As the sub-scanning means, in addition to the two pairs of nip rollers 14 and 14 shown in FIG. 1, a driving drum 14b and two non-driving nip rollers (idle nip rollers) 14a as shown in FIG. Can also be used.

The operation of this image recording apparatus will be described below. When recording an image, the drive unit 22 is a control circuit.
Controlled by 18, the shutter member 21 is set to a rotational position (open state) where the laser beam 10 is not blocked. When the image signal S is input to the modulator driving circuit 19 in this state,
The optical modulator 15 is driven by the modulator driving circuit 19 and modulates the laser beam 10 based on the image signal S.

The laser beam 10 thus modulated is deflected by the polygon mirror 13 and main-scans on the photosensitive material 12. At the same time, the photosensitive material 12 is conveyed by the pair of nip rollers 14 at a constant speed, and the laser beam 10 is sub-scanned. In this way, the photosensitive material 12 is two-dimensionally scanned and exposed by the modulated laser beam 10, so that the continuous tone image carried by the image signal S is recorded as a photographic latent image on the photosensitive material 12. To be done. After that, the photosensitive material 12 is sent to a developing device (not shown) and undergoes a developing process to visualize the photographic latent image.

Here, if the image signals S carrying each of a plurality of continuous tone images are successively supplied, those images are continuous on the long sheet photosensitive material 12 in the longitudinal direction of the photosensitive material. Will be recorded one after another. Of course, in that case, the photosensitive material 12
It is not necessary to stop the constant speed conveyance of.

On the other hand, when the image signal S carrying the image to be recorded next is not immediately supplied at the time when the recording of a certain image is completed, the photosensitive material 12 is prevented from being wastefully consumed so that the photosensitive material 12 is not wastefully consumed. The transportation is stopped. Hereinafter, how the photosensitive material 12 is conveyed at this time will be described with reference to FIGS.

FIG. 2A shows a change in the transport speed v when the transport of the photosensitive material 12 is stopped, with time. First, when one image is being recorded, the transport speed v is kept at a constant v0. Then, after the recording of this image ends at time t0, at time t1, a signal Q indicating that the image signal S indicating the image to be recorded next is not input from the modulator drive circuit 19 for example, is output from the control circuit. When input to 18, the control circuit 18 causes the nip roller pair 14,
14 brake and stop, then the nip roller pair 1
Rotate 4 and 14 in the direction opposite to the direction of rotation up to that point.

At this time, due to inertia of the drive system, the transport speed v of the photosensitive material 12 gradually decreases from v0, and the time t2
It becomes 0 (zero) at that point, and from there it reverses and increases gradually until reaching a predetermined -v0. The control circuit 18 continues the backward feeding of the photosensitive material 12 at the speed -v0 for a predetermined time,
This reverse feed is stopped at time t3. Thereupon, the photosensitive material 12 is slightly fed back by inertia, and then completely stops at time t4.

FIG. 3 shows how the photosensitive material 12 is actually conveyed up to this point. In FIG. 3, a hatched quadrangle on the photosensitive material 12 indicates the recorded image P, and an arrow A indicates the position where the laser beam 10 performs main scanning. FIG. 11A shows the position of the photosensitive material 12 at the time when the recording of the image P is just finished. Further, (b) and (c) of the same figure respectively show the position of the photosensitive material 12 at the above times t2 and t4. As shown here, the photosensitive material 12 is stopped when a part of the recorded image P returns to the rear side in the sub scanning direction from the position where the main scanning is performed.

After that, when the signal R indicating that the image signal S indicating the image to be recorded next is input from the modulator driving circuit 19 to the control circuit 18, the control circuit 18 causes the nip roller pair 14, 14 to come. Is rotated in the forward direction (direction in which the photosensitive material 12 is conveyed for sub-scanning).

At time t5 in FIG. 2, this nip roller pair 1
This is the time when the conveyance of the photosensitive material 12 by 4 and 14 is restarted. From there, the transport speed v gradually increases and reaches a predetermined v0 within a short period of time.
At 0, it will be transported at a constant speed. After entering the constant velocity transport state, the modulation of the laser beam 10 by the optical modulator 15 is started at time t6. The laser light source 11 is continuously driven without stopping so far. Further, since the polygon mirror 13 continues to be driven up to this point, main scanning and sub scanning of the laser beam 10 are performed in the same manner as described above, and the next image is exposed and recorded on the photosensitive material 12.

As described above, the image recording on the photosensitive material 12 takes a little time (t) from the time when the conveyance of the photosensitive material 12 is restarted.
Since 6-t5) has elapsed, this image is recorded in the area indicated by the chain double-dashed line in FIG. 3 (c). Nip roller pair 1 as above by control circuit 18
By controlling the drive of 4 and 14, two images can be separated by a small distance (Fig.
It is possible to record in a state of being close to each other with a margin of L (for example, about 3 mm).

On the other hand, the shutter member 21 of the shutter means 20 is
The operation of the drive unit 22 is controlled by the control circuit 18, so that the opening / closing operation is performed at the timing shown in FIG. That is, as described above, the shutter member 21 is in the open state (the laser beam 10 while the image is recorded on the photosensitive material 12).
Is not shut off). When the control circuit 18 drives the pair of nip rollers 14, 14 in the reverse direction at time t1 after the recording of one image is completed, the control circuit 18 simultaneously operates the drive unit 22 to cause the shutter member 21 to move. Is set to a closed state (a state in which the laser beam 10 is cut off).

A hatched area D1 in FIG. 2B shows a period during which the shutter member 21 shifts from the open state to the closed state, and the shutter member 21 is completely closed after this short shift period.

Then, when a short predetermined time elapses from the time t5 when the conveyance of the photosensitive material 12 in the sub-scanning direction is restarted,
The control circuit 18 operates the drive unit 22 to set the shutter member 21 in the open state. The hatched area D2 in FIG.
Indicates a period during which the shutter member 21 shifts from the closed state to the open state, and the shutter member 21 is in the completely open state at the time t6 when the image recording is restarted. Therefore, the image recording started at time t6 can be normally performed without the shutter member 21 blocking the laser beam 10.

After the recording of one image is completed, the image signal S
When the light modulator 15 is not supplied, the optical modulator 15 is naturally cut off from the laser beam 10. However, as described above, the extinction ratio of the optical modulator 15 such as AOM is about 1: 1000. It is impossible to completely block the laser beam 10 emitted by the laser light source 11 that is continuously driven.

However, since the shutter member 21 is closed as described above from the end of recording one image to the restart of the next image, leakage from the optical modulator 15 occurs. The weak laser beam 10 is blocked by the shutter member 21. As a result, this weak laser beam
The reference numeral 10 does not reach the light-sensitive material 12, so that the light-sensitive material 12 is not fogged.

In the image recording apparatus of this embodiment, since the polygon mirror 13 is driven and released even when the image is not being recorded,
If the laser beam 10 is not blocked as described above, the photosensitive material 12 which is stopped in the state of FIG.
In this case, a linear fog indicated by K will occur. Further, when the polygon mirror 13 is stopped except when recording an image, fogging occurs at one point on the straight line K (the position thereof is determined by the stop position of the polygon mirror 13). In any case, such fog is caused by the light-sensitive material.
Since it occurs in 12 areas where the image has already been recorded, the quality of the recorded image is greatly impaired.

It should be noted that, after the photosensitive material 12 is fed in the reverse direction, the trailing edge of the recorded image P coincides with the position where main scanning is performed (the position shown by the arrow A in FIG. 3) or after the recorded image P Even when the photosensitive material 12 is stopped in a state in which the edge is slightly ahead of the main scanning position in the sub-scanning direction, the quality of the recorded image is kept high by preventing the fog from occurring. The effect is obtained as described above.

Further, in the above-described embodiment, the shutter means 20 is arranged immediately after the optical modulator 15, but the shutter means 20 is not limited to this, and the shutter means 20 is provided in the optical modulator 15.
It may be arranged at a position closer to the laser light source 11 than the polygon mirror 13 or at a position closer to the photosensitive material 12 than the fθ lens 17.

Furthermore, the present invention can be applied to an image recording apparatus for recording a monochrome image. Also, if some of the three-color light sources are directly modulatable, such as LDs, others are, for example, gas lasers or SHs.
As long as it is continuously driven like a G laser, shutter means may be provided for the latter continuously driven light source. However, this does not prevent the provision of shutter means for a light source that can be directly modulated, such as an LD,
It can also be applied to a light source capable of such direct modulation. Furthermore, even when a light source that can be directly modulated, such as an LD, is used, the modulation of the light emitted from this light source is not directly modulated by controlling the current applied to the light source.
You may employ | adopt the structure which modulates with the above-mentioned external modulator.

The present invention is also applicable to an image recording apparatus for recording a plurality of images side by side on a photosensitive material which is not long, and an image recording apparatus using a rotary drum as a sub-scanning means. In this case, the same effect can be obtained.

FIG. 5 shows an embodiment of the fourth image recording apparatus of the present invention. The image recording apparatus shown in the figure records, for example, a color continuous tone image, and emits a light beam (laser beam) 10 and a semiconductor laser (LD) 11 'as a directly modifiable recording light source, and this LD1.
The drive current applied to 1'is controlled based on the image signal to directly modulate the light beam 10 emitted from the LD 11 ', and the long sheet-shaped photosensitive material 12 for deflecting the laser beam 10 and the laser beam 10. A polygon mirror 13 for upward main scanning in the direction of arrow X, a driving drum 14b as sub-scanning means for conveying the photosensitive material 12 in the longitudinal direction Y and two idle nip rollers 14a, and a laser beam on the mirror surface of the polygon mirror 13. It has a cylindrical lens 16 for forming a linear image by 10 and an fθ lens 17 for converging the laser beam 10 deflected by the polygon mirror 13 at all main scanning positions on the photosensitive material 12.

The modulation means 15 'also functions as a light beam emission stopping means for stopping the driving of the LD 11' and stopping the generation of the laser beam 10.

The polygon mirror 13 and the driving drum
14b is driven by the control circuit 18.

The operation of this image recording apparatus will be described below.

When the image signal S is input to the modulating means 15 'during image recording, the modulating means 15' modulates the current applied to the LD 11 'in accordance with the image signal S and emits it from the LD 11'. The laser beam 10 is modulated.

The laser beam 10 thus modulated is deflected by the polygon mirror 13 and main-scans on the photosensitive material 12. At the same time, the photosensitive material 12 is conveyed at a constant speed by the driving drum 14b and the two idle nip rollers 14a, and the laser beam 10 is sub-scanned.

Since the photosensitive material 12 is two-dimensionally scanned and exposed by the modulated laser beam 10 in this manner, a continuous tone image carried by the image signal S is photographed on the photosensitive material 12. Recorded as an image. Then photosensitive material
Reference numeral 12 is sent to a developing device (not shown) to undergo development processing, and the photographic latent image is visualized.

Here, if the image signals S carrying each of a plurality of continuous tone images are supplied one after another, for example, the long roll-shaped photosensitive material 12 will have those images in the longitudinal direction of the photosensitive material. It is recorded one after another in a row. Of course, in that case, it is not necessary to stop the constant speed conveyance of the photosensitive material 12.

On the other hand, when the image signal S carrying the image to be recorded next is not immediately supplied at the time when the recording of a certain image is completed, the photosensitive material 12 is prevented from being wastefully consumed so that the photosensitive material 12 is not wastefully consumed. The transportation is stopped. This photosensitive material 12
The control of the conveyance is similar to the control of the image recording apparatus of the embodiment shown in FIG. 1 described above (shown in FIG. 2), and thus the description thereof is omitted.

Here, the photosensitive material 12 has a time t0 shown in FIG.
, The modulating means 15 'reduces the applied current to the LD 11' to 0.
(Zero). As a result, the LD 11 'stops emitting the laser beam 10 almost at the same time. Since the emission of the laser beam 10 is stopped, the photosensitive material 12 is not exposed to unnecessary light.

On the other hand, the photosensitive material 12 has a time t6 in FIG.
In the above, the modulating means 15 'makes the applied current to the LD 11' in accordance with the image signal S. As a result, the LD 11 'is almost simultaneously irradiated with the laser beam 10 modulated according to the image signal S.
Is emitted. The image recording on the photosensitive material 12 is restarted by the emission of the laser beam 10.

As described above, according to the image recording apparatus of the present embodiment, the emission of the laser beam 10 is completely stopped from the end of recording one image to the restart of the next image. Fog is not caused on the photosensitive material 12.

Incidentally, the LD instantly reacts to the fluctuation of the applied current as described above, and is in the OFF state (state where the applied current is zero).
The laser beam can be emitted and stopped instantly by switching from the ON state to the ON state. For example, in the SHG laser, it takes some time until the output becomes stable. It is desirable to apply the above-mentioned shutter means. However, it is also possible to adopt a mode in which the light source is turned on / off in a range in which the tracking performance is not hindered even if the light source is turned on / off in a normal recording operation.

For example, when three light sources of R, G and B are used for recording a color image, the shutter means shown in FIG. 1 is used for the laser beams of the G and B light sources which are SHG lasers. It is desirable that the light source of R, which is an LD, is configured to completely stop the emission of the laser beam by the modulating means shown in FIG.
The emission of the laser beam may be completely stopped for all the R, G, and B light sources. With such a configuration, it is possible to reduce the number of shutter means as compared with the shutter means provided in each of R, G, and B, and particularly in the case of using mechanical shutter means, The chance of such mechanical failure is reduced, and the reliability of the device is improved.

Further, in the case where the emission of the laser beam is stopped, the total time for which the light source drives the laser beam is shortened, and as a result, it is effective in extending the life of the laser light source (improving the durability). Is.

It should be noted that, as described in the embodiment of the first image recording apparatus shown in FIG. 1, the LD as the light source is used.
Also in this embodiment using, the LD modulation may be performed not by changing the applied current, but by using an external modulator. However, the emission of the light beam from the light source is stopped by controlling the current applied to the LD.

Further, in the above-mentioned embodiment, the sub-scanning means is reversed and then stopped after the recording of one image is finished, but the effect of the present invention is to stop without being reversed. It can also be obtained in a device.

In addition, the recording material can be applied not only to an apparatus for recording on a long photosensitive material but also to an apparatus for recording a plurality of images on one sheet of photosensitive material (so-called multi-format recording). It is a thing.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an embodiment of a first image recording apparatus of the present invention.

2 is a graph showing how the photosensitive material conveyance speed changes in the image recording apparatus shown in FIG. 1 and the opening / closing timing of shutter means.

FIG. 3 is a schematic diagram showing how a photosensitive material is conveyed in the image recording apparatus shown in FIG.

FIG. 4 is a schematic view showing another embodiment of the sub-scanning means.

FIG. 5 is a schematic view showing an embodiment of a second image recording apparatus of the present invention.

[Explanation of symbols]

 10 Laser Beam 11 Laser Light Source 12 Photosensitive Material 13 Polygon Mirror 14 Nip Roller Pair 15 Optical Modulator 18 Control Circuit 20 Shutter Means 21 Shutter Member 22 Drive Unit

Claims (6)

[Claims] 1. A recording light source that emits a light beam, a main scanning unit that main-scans the light beam on a photosensitive material, and a sub-scanning unit that conveys the photosensitive material in a direction substantially orthogonal to the main-scanning direction. An optical modulator that modulates a light beam emitted from the recording light source based on an image signal, and stops the sub-scanning unit after one image is recorded on the photosensitive material, and receives a recording command for the next image. In an image recording apparatus including a control unit that drives the sub-scanning unit, in the optical path of the light beam, at least a part of a period from when one image is recorded to when the next image is recorded. An image recording apparatus comprising: a shutter means for preventing the light beam from entering the photosensitive material. 2. A recording light source which emits a light beam and which can be directly modulated, and a modulator which directly modulates the light beam emitted from the recording light source by controlling a drive current applied to the recording light source based on an image signal. A main scanning means for main scanning the light beam on the photosensitive material; a sub-scanning means for conveying the photosensitive material in a direction substantially orthogonal to the main scanning direction; and after an image is recorded on the photosensitive material. An image recording apparatus comprising: a control unit for stopping the sub-scanning unit and receiving a recording command for the next image to drive the sub-scanning unit, and recording the one image before recording the next image. The image recording apparatus is provided with a shutter means for preventing the light beam from entering the optical path and reaching the photosensitive material for at least a part of the period until the light beam reaches the photosensitive material. 3. The image recording apparatus according to claim 1, wherein the shutter unit is a mechanical shutter unit including a shutter member that moves in and out of the optical path of the light beam. 4. A recording light source that emits a light beam, a main scanning unit that main-scans this light beam on a photosensitive material, and a sub-scanning unit that conveys the photosensitive material in a direction substantially orthogonal to the main-scanning direction. An optical modulator that modulates a light beam emitted from the recording light source based on an image signal, and stops the sub-scanning unit after one image is recorded on the photosensitive material, and receives a recording command for the next image. In an image recording apparatus provided with a control unit for driving the sub-scanning unit, the recording light source is driven for at least a part of a period from the recording of one image to the recording of the next image. An image recording apparatus further comprising a light beam emission stopping means for stopping the generation of the light beam. 5. A recording light source which emits a light beam and which can be directly modulated, and a modulation means which directly modulates the light beam emitted from the recording light source by controlling a drive current applied to the recording light source based on an image signal. A main scanning means for main scanning the light beam on the photosensitive material; a sub-scanning means for conveying the photosensitive material in a direction substantially orthogonal to the main scanning direction; and after an image is recorded on the photosensitive material. An image recording apparatus comprising: a control unit for stopping the sub-scanning unit and receiving a recording command for the next image to drive the sub-scanning unit, and recording the one image before recording the next image. The image recording apparatus further comprises a light beam emission stopping means for stopping the driving of the recording light source and stopping the generation of the light beam for at least a part of the period until the light beam is emitted. 6. The control means drives the sub-scanning means in reverse after the completion of recording one image and then stops the sub-scanning means.
The image recording apparatus according to any one of the above.