JP2004145179A - Exposure apparatus and exposure method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exposure apparatus and an exposure method to make speckles in a recorded image hardly visible. <P>SOLUTION: A fiber array 31 includes two lines of light exiting part groups 31B in which a plurality of light exiting parts to make the laser beams for exposure exit are arranged into straight lines in a specified direction. In this array, one light exiting part is selected as the object from the one of the light exiting part groups 31B under conditions that a laser beam exits from the selected exiting part during exposure and that another laser beam exits from only one light exiting part of adjacent parts along the sub scanning direction in the exiting parts of the other light exiting part group 31B. When the distance between the laser beam exiting from the first light exiting part and the laser beam exiting from the adjacent exiting part on the exposed surface in the sub scanning direction is larger than a specified referential distance, the light quantity of the exiting laser beams is decreased by a specified quantity from the referential quantity corresponding to the referential distance. When the distance is smaller, similarly, the quantity of the exiting laser beam is increased by specified quantity from the referential quantity. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an exposure apparatus and an exposure method, and more particularly, to an exposure apparatus and an exposure method for scanning and exposing an exposed surface using exposure light emitted from a plurality of light sources.
[0002]
[Prior art]
Conventionally, a drum having a photosensitive material (recording medium) mounted on its outer peripheral surface is rotated in the main scanning direction, and a laser beam corresponding to image data of an image to be recorded on the photosensitive material is orthogonal to the main scanning direction. An exposure recording apparatus that records a two-dimensional image on the photosensitive material by scanning in the sub-scanning direction is widely used.
[0003]
Also, in this type of exposure recording apparatus, for the purpose of increasing the recording speed, each of the laser beams emitted from a plurality of light sources is guided to a single fiber array unit by an optical fiber, and A laser beam exit end (hereinafter referred to as a “light emitting part”) in an optical fiber is arranged in the sub-scanning direction, and exposure is performed simultaneously with a plurality of laser beams emitted from the plurality of light sources. there were. In this exposure recording apparatus, the drum is rotated in the main scanning direction, and a laser beam corresponding to the image data is simultaneously emitted from a plurality of light emitting units provided in the fiber array unit, and the fiber array unit is formed at a predetermined pitch. By moving in the sub-scanning direction, a two-dimensional image can be recorded at high speed.
[0004]
Further, in this type of exposure recording apparatus, for the purpose of increasing the resolution of a recorded image, the above-described fiber array section is composed of a plurality of light emitting sections arranged in a straight line along a predetermined direction. Are arranged in two rows perpendicular to the predetermined direction, and the fiber array unit is used in a state where the predetermined direction is inclined with respect to the sub-scanning direction.
[0005]
That is, in this exposure recording apparatus, as shown in FIG. 9 as an example, each of the one light emitting unit group is inclined by tilting the fiber array unit in which two rows of light emitting unit groups are provided with respect to the sub-scanning direction. The positions of the dots recorded on the exposed surface by the laser beam emitted from the light emitting portion in the sub-scanning direction are recorded on the exposed surface by the laser beam emitted from each light emitting portion of the other light emitting portion group. As a result, the resolution of the image recorded on the exposed surface should be higher than when the fiber array section is not inclined with respect to the sub-scanning direction. To be able to.
[0006]
By the way, as a printing technique for printing a grayscale image using a halftone dot image, there has been a technique called FM screen (FM Screen). This method expresses the density of a recorded image by the density of irregular dots having no regularity, and is less likely to cause moiré compared to a method called an AM screen that has been widely used. It has an excellent feature that tone jump does not occur.
[0007]
That is, in the AM screen, the halftone dot image of the minimum unit is composed of a relatively large number of dots, for example, a total of 196 dots of 14 (number of dots in the horizontal direction) × 14 (number of dots in the vertical direction). A grayscale image is recorded by recording point images in a two-dimensional plane. On the other hand, in the FM screen, as an example, an image composed of a relatively small number of dots, such as a total of 4 dots of 2 × 2, is scattered in a two-dimensional plane to express gradation. As described above, it is possible to prevent the occurrence of moire and tone jump.
[0008]
On the other hand, in order to evaluate the accuracy of image recording in the exposure recording apparatus, a plurality of straight lines along the main scanning direction may be recorded at a predetermined pitch in the sub scanning direction. The accuracy of image recording of the exposure recording apparatus can be evaluated by visually confirming the linearity, the presence / absence of an inclination, the state of an edge, and the like of the obtained linear image.
[0009]
In this specification, the recorded image at this time is represented by “N ON / No.”, Where N is the number of dots in the sub-scanning direction constituting the straight line, and M is the number of dots in the sub-scanning direction corresponding to the interval between the straight lines. It is called “M-off image”. For example, when the number of dots N and the number of dots M are both “2”, it is referred to as “2 on / 2 off image”.
[0010]
Here, a halftone image using an FM screen, an AM screen, or the like is used by using an exposure recording apparatus that uses the fiber array section including the two rows of light emitting section groups described above in an inclined state with respect to the sub-scanning direction. When an image is recorded by a combination of a plurality of dots, such as a gray image or an N on / M off image, each dot is recorded by a laser beam emitted from each light emitting portion.
[0011]
[Problems to be solved by the invention]
However, this exposure recording apparatus has a problem in that when a grayscale image or an N on / M off image is recorded on an FM screen, a highly visible spot (unevenness) may occur in the recorded image. .
[0012]
That is, in this exposure recording apparatus, it is premised that two rows of light emitting unit groups provided in the fiber array unit are parallel to each other. It is difficult to manufacture in parallel.
[0013]
If each light emitting portion group is not parallel, as shown in FIG. 10 as an example, the pitch interval in the sub-scanning direction of the dots recorded by the laser beam emitted from each light emitting portion group is the same. Therefore, the position in the sub-scanning direction of the dot by the laser beam emitted from one light emitting part group can be positioned at the center of the dot by the laser beam emitted from the other light emitting part group. The dots by the laser beam emitted from at least one light emitting part group are displaced from the position of the scanning line (equally spaced line corresponding to the resolution).
[0014]
The magnitude of this shift is that the pitch intervals of the light emitting portions constituting each light emitting portion group are substantially the same, so that the sub-scan is performed within the range of dots that can be recorded at one time (1 swath) by the fiber array portion. Increase or decrease regularly in the direction. Therefore, for example, when a 2-dot width image is recorded in the sub-scanning direction, the sub-scanning direction width of the image regularly increases or decreases in the sub-scanning direction within one swath.
[0015]
This will be specifically described with reference to FIG. FIG. 11 is a diagram showing the state of dots recorded on the surface to be exposed. In FIG. 11, (1) is a dot by a light emitting part group on the lower side of the fiber array part, and (2) is a fiber array. The dots by the light emission part group on the upper side of the part are respectively shown. Here, a case where a 2 on / 2 off image is recorded will be described in order to avoid complications. Further, here, the fiber array is such that the pitch interval of dots on the exposed surface by each light emitting portion group provided in the fiber array portion is equal at the center position in the sub-scanning direction of each light emitting portion group. This shows a case where the inclination angle of the part with respect to the sub-scanning direction is set.
[0016]
In this case, when recording the straight line image with the dot (1) as the left dot of the straight line image and the dot (2) as the right dot of the straight line image (referred to as “pattern A” in FIG. , “Pattern A”), the width of the recorded image in the sub-scanning direction gradually increases from the left end to the right end of the figure in the sub-scanning direction. When the straight line image is recorded using the dot (1) as the dot on the right side of the straight image (referred to as “pattern B” in FIG. 11 and hereinafter referred to as “pattern B”), the dot is recorded. It can be seen that the sub-scanning direction width of the image gradually decreases from the left end to the right end in the sub-scanning direction.
[0017]
That is, in this case, the change direction of the increase / decrease of the recording density is reversed in the pattern A and the pattern B within one swath. As described above, the recording density regularly increases / decreases within one swath, and the exposure recording apparatus moves the fiber array portion in the sub-scanning direction at a predetermined pitch to record one image. High-quality spots will occur.
[0018]
On the other hand, this type of exposure recording apparatus is usually provided with a lens such as a collimator lens and an imaging lens for condensing the laser beam emitted from the fiber array portion on the exposed surface. The lens has distortion. On the other hand, in this exposure recording apparatus, since an image is recorded in a state where the fiber array section is inclined with respect to the sub-scanning direction, as shown in FIG. 12 as an example, a light emitting section that exposes adjacent scanning lines Even so, since the distance from the position corresponding to the center of the lens is greatly different, there is a large difference in the amount of distortion of the recording dots caused by the distortion of the lens. As a result, the amount of positional deviation in the sub-scanning direction of dots that expose adjacent scanning lines differs between one light emitting unit group and the other light emitting unit group, resulting in spots in the recorded image. It becomes easy. In addition, the thick arrow in the figure shows the vector which shows the direction and magnitude | size of a distortion aberration in the position of a corresponding light emission part.
[0019]
In addition, the cause of the positional deviation of the dots on the surface to be exposed with respect to the sub-scanning direction includes errors in the pitch intervals of the light emitting sections in the fiber array section. The light emitting sections in the fiber array section described above Two factors account for most of the parallelism between groups and lens distortion.
[0020]
The present invention has been made to solve the above-described problems, and an object thereof is to provide an exposure apparatus and an exposure method that can make it difficult to visually recognize spots in a recorded image when used in an exposure recording apparatus. To do.
[0021]
[Means for Solving the Problems]
In order to achieve the above object, the exposure apparatus according to claim 1 includes a light emitting unit group configured by linearly arranging a plurality of light emitting units from which light for exposure is emitted along a predetermined direction. Two rows are provided in a direction orthogonal to the predetermined direction, and one predetermined light emission unit group is configured by the predetermined direction being inclined with respect to a predetermined sub-scanning direction. Light emitting means used in a state where the positions of each of the plurality of light emitting parts in the sub-scanning direction are alternately positioned between the plurality of light emitting parts constituting the other light emitting part group, and the light emitting means Among the plurality of light emitting portions constituting one light emitting portion group in the light emitting means and the light for condensing the light emitted from the surface to be exposed, light is emitted at the time of exposure, and the other Of the plurality of light emitting portions constituting the light emitting portion group, Only one of the light emitting parts adjacent to the scanning direction is emitted from the light emitting part adjacent to the light emitting part to be adjusted and light emitted from the light emitting part adjacent to the adjustment target light emitting part. When the distance in the sub-scanning direction on the surface to be exposed is larger than a predetermined reference distance, the amount of emitted light is decreased by a predetermined amount from the reference light amount corresponding to the reference distance. And a light amount adjusting means for adjusting the light amount of the emitted light to be increased from the reference light amount by the predetermined amount when it is small.
[0022]
According to the exposure apparatus of the first aspect, the light emitting portion group configured by arranging a plurality of light emitting portions, each of which emits light for exposure, linearly along a predetermined direction is orthogonal to the predetermined direction. A plurality of light emitting means configured to be provided in two rows in the direction in which the predetermined direction is inclined with respect to a predetermined sub-scanning direction, thereby forming a plurality of light emitting unit groups It is used in a state where the positions of the light emitting portions in the sub-scanning direction are alternately positioned between the plurality of light emitting portions constituting the other light emitting portion group. Note that the light emitting section includes a light source itself that emits the light in addition to the light emission port of the optical fiber that guides the exposure light to the light emitting means.
[0023]
According to the first aspect of the present invention, the light emitted from the light emitting means is condensed on the exposed surface by the lens. The lens includes a collimator lens, an imaging lens, and the like.
[0024]
According to the first aspect of the present invention, light is emitted at the time of exposure among the plurality of light emitting portions constituting one light emitting portion group in the light emitting means, and the other light emitting portion group is constituted. Light that is emitted from the adjustment target light emitting unit with respect to the adjustment target light emitting unit from which only one of the plurality of light emitting units adjacent to the sub-scanning direction emits light during exposure. When the distance in the sub-scanning direction on the surface to be exposed between the light emitted from the adjacent light emitting portion is larger than a predetermined reference distance, the light amount of the emitted light becomes the reference distance The light amount is adjusted by the light amount adjusting means so that the light amount of the emitted light is increased by the predetermined amount from the reference light amount.
[0025]
That is, in the present invention, the light emission part that constitutes one light emission part group and that exposes the edge part in the sub-scanning direction of the image recorded by exposure is used as the adjustment target light emission part.
[0026]
In addition, in the present invention, the light emitted from the adjustment target light emission unit and the light emission unit adjacent to the adjustment target light emission unit in the sub-scanning direction (that is, the light emission belonging to the other light emission unit group) If the distance in the sub-scanning direction on the surface to be exposed to the light emitted from the light source is larger than a predetermined reference distance, the amount of light emitted from the adjustment target light emitting part is set to the reference distance. It is assumed that the reference light amount is reduced by a predetermined amount.
[0027]
That is, in this case, since the adjustment target light emitting unit is located at a position away from the position of the adjacent light emitting unit by the reference distance, the amount of light of the adjustment target light emitting unit is The diameter of the dots recorded by the light emitted from the adjustment target light emitting portion is reduced by making it smaller than the reference light amount, and as a result, the parallelism between the light emitting portion groups, lens distortion aberration, etc. The amount of deviation of the dots recorded by the light emitted from the adjustment target light emitting portion with respect to the sub-scanning direction is apparently suppressed.
[0028]
Similarly, in the present invention, the distance in the sub-scanning direction on the exposed surface between the light emitted from the adjustment target light emitting unit and the light emitted from the adjacent light emitting unit is determined in advance. When the distance is smaller than the reference distance, the light amount of light emitted from the adjustment target light emitting unit is increased by a predetermined amount from the reference light amount corresponding to the reference distance.
[0029]
That is, in this case, since the adjustment target light emitting unit is located closer to the position away from the position of the adjacent light emitting unit by the reference distance, the light amount of the adjustment target light emitting unit is set to the reference By increasing the amount of light, the diameter of the dots recorded by the light emitted from the light emission part to be adjusted is increased, and as a result, adjustment due to parallelism between the light emission part groups, distortion of the lens, etc. The amount of deviation of the dots recorded by the light emitted from the target light emitting portion with respect to the sub-scanning direction is apparently suppressed.
[0030]
Therefore, the inclination angle of the light emitting means according to the present invention with respect to the sub-scanning direction is defined as an angle at which the light emitted from the other light emitting portion group in the light emitting means can be positioned on the scanning line on the exposed surface. By doing so, the scanning position by the light emitted from one of the light emitting unit groups can be brought close to the position of the scanning line, and as a result, the spots of the recorded image when used in the exposure recording apparatus are hardly visible. be able to.
[0031]
As described above, according to the exposure apparatus of the first aspect, light is emitted at the time of exposure among the plurality of light emitting portions constituting one light emitting portion group in the light emitting means, and the other light emitting portion. The adjustment target light with respect to the adjustment target light emitting unit from which only one of the light emitting units adjacent to the predetermined sub-scanning direction among the plurality of light emitting units constituting the group emits light during exposure. When the distance to the sub-scanning direction on the surface to be exposed between the light emitted from the emission part and the light emitted from the adjacent light emission part is larger than a predetermined reference distance, Since the light amount is reduced by a predetermined amount from the reference light amount corresponding to the reference distance, and when it is small, the light amount of the emitted light is increased by the predetermined amount from the reference light amount, When used in exposure recording equipment It can be difficult to recognize the plaques definitive recorded image.
[0032]
As in the exposure apparatus described in claim 2, it is preferable that the predetermined amount in the invention described in claim 1 is an amount corresponding to a difference between the distance in the sub-scanning direction and the reference distance. As a result, compared with the case where the predetermined amount of the present invention is an amount irrelevant to the difference, the deviation of the light emitted from one light emitting unit group in the sub-scanning direction on the exposed surface is more accurately determined. Can be suppressed.
[0033]
By the way, in the present invention, since the amount of light emitted from the adjustment target light emitting unit is adjusted, the diameter of dots recorded by the light increases or decreases. Accordingly, the increase or decrease in the diameter causes the dot size to increase or decrease not only in the sub-scanning direction but also in the main scanning direction orthogonal to the sub-scanning direction. At this time, when the image to be recorded is a gray image by the FM screen, the unit image is composed of a relatively small number of dots of about 2 × 2 dots. The quality will be greatly reduced.
[0034]
In view of this point, an exposure apparatus according to a third aspect is the invention according to the first or second aspect, in accordance with an adjustment result of a light amount of light emitted from the adjustment target light emitting unit by the light amount adjusting unit. The apparatus further includes period adjusting means for adjusting the emission period of light emitted from the adjustment target light emitting unit.
[0035]
According to the exposure apparatus of the third aspect, the period adjusting unit emits light from the adjustment target light emitting unit according to the adjustment result of the light amount of light emitted from the adjustment target light emitting unit by the light amount adjusting unit of the present invention. The light emission period to be adjusted is adjusted.
[0036]
Specifically, when the light amount adjusting unit is adjusted so that the light amount of light emitted from the adjustment target light emitting unit is smaller than the reference light amount, the dot diameter recorded by the light is the dot diameter at the reference light amount. Therefore, in order to increase the dot size in the main scanning direction, the emission period is set longer than the period for the reference light amount. Further, when the light amount adjusting means is adjusted so that the light amount of light emitted from the adjustment target light emitting unit is larger than the reference light amount, the diameter of the dot recorded by the light becomes larger than the dot diameter at the reference light amount. Therefore, in order to reduce the dot size in the main scanning direction, the emission period is made shorter than the period for the reference light amount.
[0037]
Accordingly, the diameter of the dots recorded by the light emitted from the adjustment target light emitting section can be made close to the diameter at the reference light amount, so that the quality of the recorded image can be improved.
[0038]
Thus, according to the exposure apparatus of the third aspect, the same effect as that of the first or second aspect of the invention can be achieved, and the amount of light emitted from the adjustment target light emitting unit can be reduced. Since the emission period of the light emitted from the adjustment target light emission unit is adjusted according to the adjustment result, the quality of the recorded image can be improved as compared with the case where the adjustment is not performed.
[0039]
In the present invention, it is preferable that the adjustment amount of the emission period of light emitted from the adjustment target light emitting unit is changed according to an increase / decrease amount of the light amount with respect to the reference light amount. Thereby, the quality of the recorded image can be further improved.
[0040]
By the way, as described above, there are two main causes of the positional deviation of the dots on the exposed surface with respect to the sub-scanning direction, the parallelism between the light emitting units in the light emitting means and the distortion of the lens.
[0041]
Therefore, as in an exposure apparatus according to claim 4, the distance to the sub-scanning direction of the present invention is defined as the parallelism between the one light emitting unit group and the other light emitting unit group in the light emitting unit, and the It is preferable that the distance is obtained based on at least one of the distortion aberration of the lens. Here, the parallelism of the light emitting unit group can be easily measured. Further, the distortion of the lens can be easily derived by computer simulation at the design stage of the lens. Accordingly, it is easy to derive the distance in the sub-scanning direction of the present invention using these parameters, and these parameters are the main factors of the positional deviation of the dots on the exposed surface in the sub-scanning direction. Thus, the distance in the sub-scanning direction of the present invention can be derived with high accuracy, and as a result, it is possible to make it difficult to visually recognize the spots of the recorded image when used in the exposure recording apparatus with high accuracy.
[0042]
On the other hand, in order to achieve the above object, the exposure method according to claim 5 is a light emitting part configured by arranging a plurality of light emitting parts from which exposure light is emitted in a straight line along a predetermined direction. Two groups are provided in a direction orthogonal to the predetermined direction, and the predetermined direction is inclined with respect to a predetermined sub-scanning direction, whereby one light emitting unit group is formed. Scanning using light emitting means used in a state where the positions of each of the plurality of light emitting parts constituting the second light emitting part group are alternately positioned with respect to the sub-scanning direction. An exposure method in an exposure apparatus for performing exposure, wherein light is emitted at the time of exposure among a plurality of light emitting portions constituting one light emitting portion group in the light emitting means, and the other light emitting portion group is constituted The sub-scanning method of the plurality of light emitting parts With respect to an adjustment target light emitting unit in which only one of the adjacent light emitting units emits light during exposure, light emitted from the adjustment target light emitting unit and light emitted from the adjacent light emitting unit If the distance in the sub-scanning direction on the surface to be exposed is larger than a predetermined reference distance, the amount of emitted light is reduced by a predetermined amount from the reference amount corresponding to the reference distance. If it is small, the light amount of the emitted light is adjusted to be increased from the reference light amount by the predetermined amount.
[0043]
Therefore, according to the exposure method of the fifth aspect, since it operates in the same manner as the invention of the first aspect, the spot of the recorded image when used in the exposure recording apparatus is the same as the first aspect of the invention. Can be made difficult to be visually recognized.
[0044]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Hereinafter, a case where the exposure apparatus and the exposure method of the present invention are applied to a laser recording apparatus will be described. First, the configuration of a laser recording apparatus 10 according to the present embodiment will be described with reference to FIG.
[0045]
As shown in the figure, a laser recording apparatus 10 according to the present embodiment condenses a light source unit 20 that generates a plurality of laser beams and a plurality of laser beams generated by the light source unit 20 on an exposed surface. An exposure head 30, an exposure head moving unit 40 that moves the exposure head 30 along the sub-scanning direction, and a recording film F on which an image is recorded are mounted, and the recording film F moves in the main scanning direction. 1 and a drum 50 that is driven to rotate in the direction of arrow R.
[0046]
The light source unit 20 includes a light source substrate 24 on the surface of which a plurality of semiconductor lasers 21 each composed of a broad area semiconductor laser in which one end of an optical fiber 22 is individually coupled, and one end of the light source substrate 24. An adapter substrate 25 provided with a plurality of adapters of the SC type optical connector 25A (the same number as that of the semiconductor laser 21) is mounted vertically, and is horizontally mounted on the other end portion of the light source substrate 24 and an image to be recorded on the recording film F And an LD driver substrate 27 provided with an LD driver circuit 26 (see also FIG. 3) for driving the semiconductor laser 21 in accordance with image data.
[0047]
The other end portions of the plurality of optical fibers 22 are each provided with a plug of an SC type optical connector 25 </ b> A, and the plug is fitted into one insertion port of an adapter provided on the adapter substrate 25. Accordingly, the laser beam emitted from each semiconductor laser 21 is transmitted to the approximate center position of the adapter provided on the adapter substrate 25 by the optical fiber 22.
[0048]
In addition, output terminals for driving signals of the semiconductor laser 21 in the LD driver circuit 26 provided on the LD driver substrate 27 are individually connected to the semiconductor laser 21, and each semiconductor laser 21 is respectively connected by the LD driver circuit 26. The drive is controlled individually.
[0049]
On the other hand, the exposure head 30 includes a fiber array unit 31 that collectively emits the laser beams emitted from the plurality of semiconductor lasers 21. The fiber array unit 31 is provided on the adapter substrate 25. Laser beams emitted from the respective semiconductor lasers 21 are transmitted by a plurality of optical fibers 70 in which plugs of SC type optical connectors provided at one end are fitted into the other insertion ports of the plurality of adapters.
[0050]
FIG. 2 shows the configuration of the fiber array unit 31 when viewed in the direction of arrow A in FIG. As shown in the figure, the fiber array unit 31 according to the present embodiment has two bases 31A each provided on one side so that half of the V-shaped grooves of the semiconductor laser 21 are adjacent to each other. The grooves are arranged so as to face each other, and one end of each optical fiber 70 (corresponding to the “light emitting portion” of the present invention) is fitted into each V-shaped groove one by one. Therefore, a plurality of laser beams emitted from the respective semiconductor lasers 21 are simultaneously emitted from the fiber array unit 31 at predetermined intervals.
[0051]
That is, in the fiber array unit 31 of the present embodiment, the light emitting unit group 31B configured by arranging a plurality of light emitting units in a straight line along a predetermined direction is provided in two rows in a direction orthogonal to the predetermined direction. Is configured.
[0052]
In the laser recording apparatus 10 according to the present embodiment, the fiber array unit 31 configured as described above is in a state where the predetermined direction is inclined with respect to the sub-scanning direction, and one light emitting unit The plurality of light emitting portions constituting the group 31B are used in a state where the positions in the sub-scanning direction are positioned between the plurality of light emitting portions constituting the other light emitting portion group 31B.
[0053]
In the present embodiment, the pitch interval in the sub-scanning direction of each dot formed on the recording film F by the laser beam emitted from the two rows of light emitting part groups 31B provided in the fiber array part 31 is as follows. The inclination angle of the fiber array section 31 with respect to the sub-scanning direction is set so as to be equally spaced at the center position in the sub-scanning direction of the light emitting section group 31B.
[0054]
On the other hand, as shown in FIG. 1, in the exposure head 30, a collimator lens 32, an aperture member 33, and an imaging lens 34 are arranged in this order from the fiber array unit 31 side. The opening member 33 is arranged so that the opening is positioned at the far field when viewed from the laser beam exit of the fiber array section 31. As a result, an equivalent light amount limiting effect can be given to all laser beams emitted from the emission ports of the plurality of optical fibers 70 in the fiber array section 31.
[0055]
On the other hand, the exposure head moving unit 40 is provided with a ball screw 41 and two rails 42 arranged so that the longitudinal direction thereof is along the sub-scanning direction, and a sub-scanning motor 43 (FIG. 3) that rotationally drives the ball screw 41. , The exposure head 30 disposed on the ball screw 41 can be moved in the sub-scanning direction while being guided by the rail 42.
[0056]
Further, the drum 50 can be rotated in the direction of arrow R in FIG. 1 by operating a main scanning motor 51 (see also FIG. 3), whereby main scanning is performed.
[0057]
In this embodiment, a multimode optical fiber having a relatively large core diameter is applied as the optical fiber 22 and the optical fiber 70 in order to increase the output of the laser beam.
[0058]
Next, the configuration of the control system of the laser recording apparatus 10 according to the present embodiment will be described with reference to FIG. As shown in the figure, the control system includes an LD driver circuit 26 that drives each semiconductor laser 21 according to image data, a main scanning motor drive circuit 81 that drives a main scanning motor 51, and a sub-scanning motor 43. A sub-scanning motor driving circuit 82 for driving, a memory 83 mainly composed of a nonvolatile memory (in this embodiment, a flash memory) that mainly stores light amount adjustment information to be described later, an LD driver circuit 26, and a main scanning motor driving And a control circuit 80 for controlling the circuit 81 and the sub-scanning motor drive circuit 82. Here, the control circuit 80 is supplied with image data indicating an image to be recorded on the recording film F. In addition, a memory 83 is connected to the control circuit 80, and the control circuit 80 can read information stored in the memory 83.
[0059]
By the way, in the laser recording apparatus 10 according to the present embodiment, sub-scanning of dots recorded on the recording film F caused by the deviation in parallelism in the two rows of light emitting unit groups 31B provided in the fiber array unit 31 is performed. The amount of deviation with respect to the direction and the amount of deviation in the sub-scanning direction of the dot due to the distortion of the collimator lens 32 and the imaging lens 34 are divided into one light emitting section group 31B (in this embodiment, the upper-stage light The emission unit group 31B) is used as a target stage, and the light intensity of the laser beam emitted from the light emission unit group 31B set as the target stage is adjusted to be reduced.
[0060]
Specifically, among the plurality of light emitting units constituting the upper light emitting unit group 31B as the target stage, a laser beam is emitted during exposure, and the other light emitting unit group 31B (lower light unit) Among all the light emitting parts constituting the emitting part group 31B), only one of the light emitting parts adjacent to the sub-scanning direction is subject to light quantity adjustment for all the light emitting parts from which laser beams are emitted during exposure. It is set as the adjustment object light emission part.
[0061]
For all the adjustment target light emitting portions, the distance in the sub-scanning direction on the exposed surface between the laser beam emitted from the light emitting portion and the laser beam emitted from the adjacent light emitting portion is set in advance. When the distance is larger than the predetermined reference distance, the light amount of the emitted laser beam is reduced by a predetermined adjustment amount from the reference light amount corresponding to the reference distance, and when smaller, the light amount of the emitted laser beam is decreased. Adjustment is made so that the reference light amount is increased by the adjustment amount.
[0062]
The light amount adjustment information stored in the memory 83 in advance is information indicating an adjustment amount when adjusting the light amount of the laser beam as described above. Hereinafter, the light amount adjustment information according to the present embodiment will be described in detail with reference to FIGS. Here, the pitch interval in the case where there is no deviation in the pitch interval in the sub-scanning direction of the dots recorded on the recording film F by the laser beam emitted from each light emitting portion group 31B, that is, one light emission. Laser beam emitted from a plurality of light emitting portions constituting the other light emitting portion group 31B in which the positions in the sub-scanning direction of the dots recorded by the laser beams emitted from the plurality of light emitting portions constituting the portion group 31B A case in which the pitch interval when the dot is recorded at the center of the recording medium is set as a reference distance and the light amount of the laser beam in this case is set as a reference light amount will be described.
[0063]
First, a case will be described in which attention is paid only to the shift in parallelism of the two rows of light emitting unit groups 31B provided in the fiber array unit 31. FIG.
[0064]
In each light emitting part group 31B, since the pitch interval between each light emitting part is substantially constant, when each light emitting part group 31B is not parallel, light is emitted from the light emitting part constituting one light emitting part group 31B. Dots recorded on the recording film F by the laser beam thus formed, and dots recorded by the laser beam emitted from the light emitting portion constituting the other light emitting portion group 31B adjacent to the recording film F in the sub-scanning direction, Is regularly increased or decreased with respect to the sub-scanning direction.
[0065]
In the present embodiment, the pitch interval of dots on the recording film F by the laser beam emitted from each light emitting portion group 31B is at a position corresponding to the center position in the sub-scanning direction of the light emitting portion group 31B. Since the inclination angle of the fiber array unit 31 with respect to the sub-scanning direction is set so as to be spaced, the light quantity of the laser beam emitted from the light emitting unit located at the center of the light emitting unit group 31B in the sub-scanning direction is the reference. The amount of light adjustment is reversed with respect to the reference light amount, with the light emission portion as a boundary.
[0066]
From the above, in the laser recording apparatus 10 according to the present embodiment, the light amount adjustment amount when only focusing on the parallelism of the two rows of the light emitting unit groups 31B provided in the fiber array unit 31 is illustrated as an example. As shown in FIG. 4 (A), a light emitting portion (in the example shown in the figure, the straight line having an inclination angle corresponding to the parallel degree and located at the center in the sub-scanning direction of the light emitting portion group 31B. This is represented by a straight line in which the light amount adjustment amount of the light emission portion (44 channel ') is zero.
[0067]
In FIG. 4A, the inclination angle of the light emitting portion group 31B at the target stage with respect to the sub-scanning direction is smaller than the other light emitting portion group 31B (as an example, shown in FIGS. 10 and 11). This is shown in the case of a state).
[0068]
In this case, the distance in the sub-scanning direction from the dot by the adjustment target light emitting unit to the dot adjacent to the sub-scanning direction is the start point side of the dot by the adjustment target light emitting unit in the sub-scanning direction (FIG. 11). In the example shown in FIG. 11, the one located on the left side of FIG. 11 gradually increases in the sub-scanning direction, and conversely, the adjacent dot is the end point in the sub-scanning direction (shown in FIG. In the example, the one located on the right side of FIG. 11 becomes gradually smaller in the sub-scanning direction.
[0069]
Accordingly, the light amount adjustment information in this case is after adjustment when the light emitting unit adjacent to the adjustment target light emitting unit on the side of the starting point in the sub-scanning direction emits a laser beam, as shown in FIG. If the light emission part adjacent to the end point in the sub-scanning direction of the adjustment target light emitting part emits a laser beam, the light quantity after adjustment becomes The light amount adjustment amount AR gradually increases in the sub-scanning direction.
[0070]
Next, a case where attention is paid only to the distortion aberration of the collimator lens 32 and the imaging lens 34 will be described.
[0071]
In general, the distortion aberration of a lens gradually increases from the center position of the lens toward the outer periphery. The fiber array unit 31 is used so that the center position of the light emitting unit group 31B corresponds to the centers (optical axes) of the collimator lens 32 and the imaging lens 34.
[0072]
From the above, in the laser recording apparatus 10 according to the present embodiment, the light amount adjustment amount when focusing only on the distortion aberration of the collimator lens 32 and the imaging lens 34 is as shown in FIG. 4B as an example. , A light emitting portion (in the example shown in the figure, the '44 channel in a curve corresponding to the total distortion of the collimator lens 32 and the imaging lens 34 and located in the center of the light emitting portion group 31B in the sub-scanning direction). It is represented by a curve in which the light amount adjustment amount of the “light emitting part” is zero.
[0073]
In this case, the distance in the sub-scanning direction from the dot by the adjustment target light emitting unit moved by the distortion to the adjacent dot in the sub-scanning direction is the distance between the adjacent dot and the dot by the adjustment target light emitting unit. For those located on the start point side in the sub-scanning direction, the size gradually increases from both end positions in the sub-scanning direction toward the center position. For those that do, it gradually decreases from the position of both ends in the sub-scanning direction toward the center position.
[0074]
Therefore, the light amount adjustment information in this case is after adjustment when the light emitting part adjacent to the adjustment target light emitting part on the side of the starting point in the sub-scanning direction emits a laser beam, as shown in FIG. Is a light amount adjustment amount BL that gradually decreases from both end positions toward the center position, and the light emitting part adjacent to the adjustment target light emitting part on the start point side in the sub-scanning direction emits a laser beam. The light quantity after adjustment becomes a light quantity adjustment amount BR that gradually increases from both end positions toward the center position.
[0075]
As a result of the above, the light amount adjustment information that can deal with both of the parallelism shift in the light emitting portion group 31B and the distortion aberration of the collimator lens 32 and the imaging lens 34 is shown in FIGS. The laser recording apparatus according to the present embodiment is obtained as shown in FIG. 5 as an example, which is obtained by adding each light amount adjustment information shown in (B) for each light emitting unit constituting the target stage. 10, such light amount adjustment information is stored in the memory 83 in advance. Here, CL in the figure indicates light amount adjustment information when the laser beam is emitted from the light emitting unit adjacent to the adjustment target light emitting unit on the start point side in the sub scanning direction, and CR indicates the adjustment target light emitting unit in the sub scanning direction. The light amount adjustment information when the laser beam is emitted from the light emitting unit adjacent to the end point side is shown.
[0076]
In the present embodiment, the parallelism of the light emitting unit group 31B is obtained by actual measurement, and the overall distortion of the collimator lens 32 and the imaging lens 34 is obtained by computer simulation at the time of designing these lenses. ing. Then, based on these parameters, calculate the distance in the sub-scanning direction between the light emitting unit constituting the light emitting unit group 31B that is the target stage and the light emitting unit adjacent thereto in the sub-scanning direction, Based on the comparison result between the distance and the reference distance, light amount adjustment information CL and light amount adjustment information CR are derived and stored in the memory 83.
[0077]
The fiber array unit 31 corresponds to the light emitting means of the present invention, the collimator lens 32 and the imaging lens 34 correspond to the lens of the present invention, and the LD driver circuit 26 corresponds to the light amount adjusting means and the period adjusting means of the present invention.
[0078]
Next, the operation of the laser recording apparatus 10 configured as described above will be described with reference to the flowchart shown in FIG. FIG. 6 is a flowchart showing a flow of processing when image recording is performed by the laser recording apparatus 10. Here, a case will be described in which the laser recording apparatus 10 is configured to be able to record both grayscale images and 2-on / 2-off images using an FM screen.
[0079]
First, in step 100, image data of an image to be recorded on the recording film F is transferred to the control circuit 80 from an image memory (not shown) that temporarily stores the image data of the image in recording the image. The control circuit 80 drives the LD driver circuit 26, the main scanning motor driving circuit 81, and the sub-scanning motor driving signals that are adjusted based on the transferred image data and the resolution data indicating the predetermined resolution of the recorded image. Supply to circuit 82.
[0080]
In the next step 102, the main scanning motor drive circuit 81 causes the main scanning motor to rotate the drum 50 in the direction of arrow R in FIG. 1 at a rotational speed corresponding to the resolution data based on the signal supplied from the control circuit 80. 51, the sub-scanning motor driving circuit 82 sets a feed interval of the exposure head 30 in the sub-scanning direction by the sub-scanning motor 43 according to the resolution data.
[0081]
In the next step 106, LD light emission adjustment processing is executed by the LD driver circuit 26 based on the image data supplied from the control circuit 80. Hereinafter, the LD light emission adjustment process according to the present embodiment will be described with reference to FIG.
[0082]
First, in step 200, for all the semiconductor lasers 21 that emit laser beams, the above-described reference light amount is set as the light amount of the laser beam, and a period according to the supplied image data is set as the light emission period. In step 202, the light amount adjustment information CL and the light amount adjustment information CR corresponding to all the light emitting units constituting the upper light emitting unit group 31B stored in advance in the memory 83 are read.
[0083]
In the next step 204, any one of the laser beam emitted from the light emitting units constituting the upper light emitting unit group 31B is set as a point of interest, and the lower side adjacent to the point of interest in the sub-scanning direction is set as the point of interest. It is determined based on the supplied image data whether or not only the starting point side of the light emitting part of the light emitting part group 31B is emitted. If the determination is affirmative, the process proceeds to step 206.
[0084]
In step 206, the light amount of the laser beam emitted from the light emitting unit as the point of interest is added to the light amount adjustment amount indicated by the light amount adjustment information CL corresponding to the light emitting unit to the light amount set in step 200. Then, the process proceeds to step 212.
[0085]
On the other hand, if a negative determination is made in step 204, the process proceeds to step 208, and the laser beam is applied only to the end point side of the light emitting part of the lower light emitting part group 31B adjacent to the point of interest in the sub-scanning direction. Whether to inject is determined based on the supplied image data. If the determination is affirmative, the process proceeds to step 210.
[0086]
In step 210, the light amount of the laser beam emitted from the light emitting portion as the point of interest is added to the light amount adjustment amount indicated by the light amount adjustment information CR corresponding to the light emitting portion to the light amount set in step 200. Then, the process proceeds to step 212.
[0087]
In step 212, it is determined based on the supplied image data whether the image to be recorded is an image by an FM screen. If the determination is affirmative, the process proceeds to step 214, and the light is emitted from the light emitting unit that is the point of interest. If the light amount adjustment amount applied in step 206 or step 210 is a positive value, the laser beam emission period (emission period) is shortened by the time corresponding to the adjustment amount, and conversely the light amount If the adjustment amount is a negative value, adjustment is made to lengthen the time corresponding to the adjustment amount, and then the process proceeds to step 216.
[0088]
That is, since the diameter of the dot recorded by the laser beam is increased or decreased by adjusting the light amount of the laser beam in the above step 206 or step 210, the dot size is not only in the sub-scanning direction but also in the main scanning direction. It gets bigger. At this time, when the image to be recorded is a gray-scale image by the FM screen, the unit image is composed of a relatively small number of dots of about 2 × 2 dots, so the change in the dot size with respect to the main scanning direction is recorded. The image quality is greatly reduced. The adjustment of the light emission period in step 214 is performed in order to suppress this deterioration in image quality.
[0089]
On the other hand, if a negative determination is made in step 208 and a negative determination is made in step 212, the process proceeds to step 216.
[0090]
In step 216, it is determined whether or not the processing in steps 204 to 214 has been completed for all the laser beams emitted from the light emitting units constituting the upper light emitting unit group 31B. Returns to step 204 and ends the LD light emission adjustment process when the determination is affirmative.
[0091]
When the LD light emission adjustment process ends, the process proceeds to step 108 (see FIG. 6), and the drive of the semiconductor laser 21 is controlled based on the light amount and the light emission period set by the LD light emission adjustment process.
[0092]
The laser beam L emitted from each semiconductor laser 21 is emitted from the fiber array unit 31 via the optical fiber 22, the SC type optical connector 25A, and the optical fiber 70. After being collimated by the collimator lens 32, the aperture member 33 is used. The amount of light is limited by the above, and the light is condensed on the recording film F on the drum 50 through the imaging lens 34.
[0093]
In this case, a plurality of dots are formed on the recording film F according to the plurality of laser beams L emitted from the respective semiconductor lasers 21. With these dots, the exposure head 30 is fed in the sub-scanning direction at the pitch of the feeding interval set in step 104, and the two-dimensional image is formed on the recording film F by the rotation of the drum 50 started in step 102. Formed.
[0094]
When the recording of the two-dimensional image on the recording film F is completed, in the next step 110, the main scanning motor driving circuit 81 stops the rotation driving of the main scanning motor 51, and then this processing is ended.
[0095]
By the above processing, the state of dots recorded on the exposed surface shown in FIG. 11 can be changed to the state shown in FIG. 8 as an example. As can be seen from the figure, in both patterns A and B, the width of the recorded image in the sub-scanning direction is made closer to the width of the central portion in the sub-scanning direction from one end to the other end in the sub-scanning direction. As a result, it is possible to make it difficult to see the spots of the recorded image.
[0096]
As described above in detail, the laser recording apparatus 10 according to the present embodiment has a laser beam emitted from the plurality of light emitting units constituting the light emitting unit group 31B as the target stage in the fiber array unit 31 during exposure. Adjustment target light emission in which only one of the plurality of light emission portions that are emitted and adjacent to the sub-scanning direction among the plurality of light emission portions constituting the other light emission portion group 31B is emitted during exposure. The distance in the sub-scanning direction on the exposed surface between the laser beam emitted from the adjustment target light emitting unit and the laser beam emitted from the adjacent light emitting unit is determined from a predetermined reference distance. If it is large, the light amount of the emitted laser beam is reduced by a predetermined amount from the reference light amount corresponding to the reference distance, and if it is small, the light amount of the emitted laser beam is Since as assumed that increased by the predetermined amount from the quasi-light amount may be difficult to view the plaque of the recorded image.
[0097]
Further, the laser recording apparatus 10 according to the present embodiment is configured such that the predetermined amount is an exposed surface between the laser beam emitted from the adjustment target light emitting unit and the laser beam emitted from the adjacent light emitting unit. Since the amount is determined in accordance with the difference between the distance in the sub-scanning direction and the reference distance, the light is emitted from the light emitting unit group 31B as the target stage as compared with the amount that is not related to the difference. The deviation of the laser beam on the exposed surface with respect to the sub-scanning direction can be suppressed more accurately.
[0098]
In addition, the laser recording apparatus 10 according to the present embodiment adjusts the emission period of the laser beam emitted from the adjustment target light emitting unit according to the adjustment result of the light amount of the laser beam emitted from the adjustment target light emitting unit. Therefore, the quality of the recorded image can be improved as compared with the case where the adjustment is not performed.
[0099]
Further, the laser recording apparatus 10 according to the present embodiment changes the adjustment amount of the light emission period emitted from the adjustment target light emission unit according to the amount of increase / decrease of the light amount with respect to the reference light amount. The quality of the can be further improved.
[0100]
Further, the laser recording apparatus 10 according to the present embodiment has the sub-scanning direction on the exposed surface between the laser beam emitted from the adjustment target light emitting unit and the laser beam emitted from the adjacent light emitting unit. Is a distance obtained on the basis of both the parallelism of the two light emitting section groups 31B in the fiber array section 31 and the distortion aberration of the collimator lens 32 and the imaging lens 34. It is possible to make it difficult to visually recognize the spots of the recorded image.
[0101]
Further, the laser recording apparatus 10 according to the present embodiment stores light amount adjustment information indicating the light amount adjustment amount for each light emitting unit constituting the light emitting unit group 31B as the target stage in the memory 83 in advance. Since the light amount of the laser beam emitted from the adjustment target light emitting unit is adjusted using information, the light amount can be adjusted easily and at a higher speed than when the light amount adjustment amount is derived during image recording. it can.
[0102]
In the present embodiment, the case where the amount of light of the laser beam and the light emission period are adjusted in accordance with both the parallelism of the light emitting portion group 31B and the distortion aberration of the collimator lens 32 and the imaging lens 34 has been described. However, the present invention is not limited to this, and a configuration in which the amount of light of the laser beam and the light emission period are adjusted in correspondence with only the parallelism of the light emitting unit group 31B, and the distortion of the collimator lens 32 and the imaging lens 34. It is also possible to adjust the light amount and the light emission period of the laser beam corresponding to only the aberration. Further, when applied to an FM screen, the light emission period may be adjusted by increasing or decreasing the amount of light corresponding to the distance.
[0103]
When only the parallelism of the light emitting unit group 31B is supported, instead of the light amount adjustment information CL and the light amount adjustment information CR in the present embodiment, as an example, the light amount adjustment information AL and the light amount adjustment shown in FIG. Information AR is stored in the memory 83 in advance. Further, in the case of dealing only with lens distortion aberration, instead of the light amount adjustment information CL and the light amount adjustment information CR, as an example, the light amount adjustment information BL and the light amount adjustment information BR shown in FIG. Remember. Other configurations and processes are the same as those in the present embodiment. In these cases, the effect of making it difficult to visually recognize the spots of the recorded image can be expected to some extent.
[0104]
In the present embodiment, the adjustment amount of the light amount of the laser beam emitted from the adjustment target light emitting unit is stored in advance, and the light amount adjustment is performed using this amount. For example, the amount of deviation between dots in the sub-scanning direction on the exposed surface of the laser beam emitted from the fiber array unit 31 is stored in advance, and adjustment is performed based on the amount of deviation. An adjustment amount of the light amount of the laser beam emitted from the target light emitting unit may be calculated. Also in this case, the same effects as in the present embodiment can be obtained.
[0105]
Further, in the present embodiment, information associating the light emission units constituting the light emission unit group that is the target stage as the light amount adjustment information and the light amount adjustment amounts corresponding to the light emission units is stored, Although the case where the amount of adjustment of the light amount of the laser beam emitted from the adjustment target light emitting unit is obtained by reading the information has been described, the present invention is not limited to this, for example, the channel of the light emitting unit A function that takes a number as an input and outputs a light amount adjustment amount corresponding to the number is derived and stored, and the adjustment amount of the light amount of the laser beam emitted from the adjustment target light emitting unit is calculated using the function. It can also be in the form. In this case, the storage capacity can be greatly reduced as compared with the case where the light amount adjustment information is stored.
[0106]
In the present embodiment, the pitch interval in the sub-scanning direction of each dot formed on the recording film F by the laser beam emitted from the two rows of light emitting part groups 31B provided in the fiber array part 31 is as follows. Although the case where the inclination angle with respect to the sub-scanning direction of the fiber array unit 31 is set so as to be equidistant at the center position in the sub-scanning direction of the light emitting unit group 31B, the present invention is not limited to this. For example, the inclination angle of the fiber array unit 31 may be set such that the pitch interval is equal at the left end or right end position in the sub-scanning direction of the light emitting unit group 31B. Also in this case, the same effects as in the present embodiment can be obtained.
[0107]
In the present embodiment, the sub-scanning direction on the surface to be exposed between the laser beam emitted from the adjustment target light emitting unit and the laser beam emitted from the light emitting unit adjacent thereto in the sub-scanning direction. The case where the light amount of the laser beam emitted from the adjustment target light emitting unit is adjusted by an amount corresponding to the difference between the distance to the reference distance and the reference distance has been described, but the present invention is not limited to this, It is also possible to adjust the amount by a fixed amount. The LD light emission adjustment process in this case is the one shown in FIG. 7, in which the process in step 202 is deleted, and the processes in step 206 and step 210 each add or subtract the fixed amount from the reference light amount. It becomes. In this case, it is not necessary to store the light amount adjustment information in the memory 83. Therefore, in this case, the LD light emission adjustment process can be simplified and the storage capacity for storing the light amount adjustment information can be reduced.
[0108]
Further, in the present embodiment, the case where the target stage is the upper side light emitting section group 31B has been described, but the present invention is not limited to this, and the lower stage side light emitting section group 31B is used as the target stage. It goes without saying that it can also be. Also in this case, the same effects as in the present embodiment can be obtained.
[0109]
Further, the flowcharts (FIGS. 6 and 7) shown in the present embodiment are merely examples, and it is needless to say that changes can be made as appropriate without departing from the gist of the present invention.
[0110]
【The invention's effect】
As described above in detail, according to the exposure apparatus and the exposure method of the present invention, light is emitted at the time of exposure among a plurality of light emitting portions constituting one light emitting portion group in the light emitting means, and Regarding the adjustment target light emitting unit in which only one of the light emitting units adjacent to the predetermined sub-scanning direction among the plurality of light emitting units constituting the other light emitting unit group emits light during exposure. When the distance in the sub-scanning direction on the exposed surface between the light emitted from the adjustment target light emitting unit and the light emitted from the adjacent light emitting unit is larger than a predetermined reference distance The amount of emitted light is reduced by a predetermined amount from the reference light amount corresponding to the reference distance, and if it is small, the amount of emitted light is increased by the predetermined amount from the reference light amount. So exposure Can be difficult to view the plaque of the recorded image at the time used in the recording apparatus, the effect is obtained that.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram (perspective view) of a laser recording apparatus 10 according to an embodiment.
FIG. 2 is a detailed configuration diagram of a fiber array unit 31 according to the embodiment.
FIG. 3 is a block diagram showing a configuration of a control system of the laser recording apparatus 10 according to the embodiment.
4A and 4B are diagrams for explaining light amount adjustment information according to the embodiment, and FIG. 4A is an example of light amount adjustment information corresponding only to the parallelism of two rows of light emitting unit groups 31B in the fiber array unit 31; (B) is a graph showing an example of light amount adjustment information corresponding only to the distortion aberration of the lens.
FIG. 5 is a diagram for explaining light amount adjustment information according to the embodiment, and an example of light amount adjustment information corresponding to the parallelism of two rows of light emitting unit groups 31B and the distortion aberration of a lens in the fiber array unit 31; It is a graph to show.
FIG. 6 is a flowchart showing a flow of processing when image recording is performed by the laser recording apparatus according to the embodiment.
7 is a flowchart showing a flow of an LD light emission adjustment process executed during the execution of the process shown in FIG.
FIG. 8 is a schematic diagram for explaining the effect of the present invention.
FIG. 9 shows the state of dots recorded on an exposed surface by a laser beam emitted from each light emitting portion when a fiber array portion having two rows of light emitting portion groups is inclined with respect to the sub-scanning direction. It is a schematic diagram which shows.
FIG. 10 is a schematic diagram for explaining a problem in a case where two rows of light emitting unit groups provided in the fiber array unit are not parallel.
FIG. 11 is a schematic diagram for specifically explaining a problem in a case where two rows of light emitting unit groups provided in the fiber array unit are not parallel.
FIG. 12 is a schematic diagram for explaining a problem caused by distortion of a lens provided in the exposure recording apparatus.
[Explanation of symbols]
10 Laser recording device
21 Semiconductor laser
26 LD driver circuit (light quantity adjustment means, period adjustment means)
31 Fiber array part (light emission means)
32 Collimator lens (lens)
34 Imaging lens (lens)
80 Control circuit

Claims (5)

A plurality of light emitting portions each having a plurality of light emitting portions from which light for exposure is emitted is arranged in a straight line along a predetermined direction, and arranged in two rows in a direction orthogonal to the predetermined direction. The predetermined direction is inclined with respect to a predetermined sub-scanning direction, so that the position of each of the plurality of light emitting units constituting one light emitting unit group in the sub-scanning direction is set to the other. Light emitting means used in a state of being alternately positioned between a plurality of light emitting portions constituting the light emitting portion group;
A lens for condensing the light emitted from the light emitting means on the exposed surface;
Of the plurality of light emitting portions constituting one light emitting portion group in the light emitting means, light is emitted at the time of exposure, and the sub-scanning among the plurality of light emitting portions constituting the other light emitting portion group Only one of the light emitting parts adjacent to the direction is emitted from the adjustment target light emitting part and the light emitting part adjacent to the adjustment target light emitting part from which light is emitted at the time of exposure. When the distance in the sub-scanning direction on the exposed surface with respect to light is larger than a predetermined reference distance, the light amount of the emitted light is decreased by a predetermined amount from the reference light amount corresponding to the reference distance A light amount adjusting means for adjusting the light amount of the emitted light to be increased from the reference light amount by the predetermined amount when it is small;
An exposure apparatus comprising: The exposure apparatus according to claim 1, wherein the predetermined amount is an amount corresponding to a difference between the distance in the sub-scanning direction and the reference distance. The apparatus further comprises a period adjusting unit that adjusts an emission period of light emitted from the adjustment target light emitting unit according to a result of adjustment of a light amount of light emitted from the adjustment target light emitting unit by the light amount adjusting unit. The exposure apparatus according to claim 1 or 2. The distance with respect to the sub-scanning direction is a distance obtained based on at least one of the parallelism between the one light emitting part group and the other light emitting part group in the light emitting means and the distortion aberration of the lens. The exposure apparatus according to any one of claims 1 to 3. A plurality of light emitting portions each having a plurality of light emitting portions from which light for exposure is emitted is arranged in a straight line along a predetermined direction, and arranged in two rows in a direction orthogonal to the predetermined direction. The predetermined direction is inclined with respect to a predetermined sub-scanning direction, so that the position of each of the plurality of light emitting units constituting one light emitting unit group in the sub-scanning direction is set to the other. An exposure method in an exposure apparatus that performs scanning exposure using light emitting means used in a state of being alternately positioned between a plurality of light emitting portions constituting a light emitting portion group,
Of the plurality of light emitting portions constituting one light emitting portion group in the light emitting means, light is emitted at the time of exposure, and the sub-scanning among the plurality of light emitting portions constituting the other light emitting portion group Only one of the light emitting parts adjacent to the direction is emitted from the adjustment target light emitting part and the light emitting part adjacent to the adjustment target light emitting part from which light is emitted at the time of exposure. When the distance to the exposed surface with respect to the light in the sub-scanning direction is larger than a predetermined reference distance, the amount of emitted light is reduced by a predetermined amount from the reference light amount corresponding to the reference distance And an exposure method that adjusts the light amount of the emitted light to be increased from the reference light amount by the predetermined amount when it is small.

Images