JPH1178110A - Image recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shift the intensity of exposure easily and stably in a short time for all laser beams emitted from a plurality of laser diodes at the time of changing the frequently required tone reproduction of output image or the recording material. SOLUTION: The image recorder comprises an optical system 20 for arranging the laser beams emitted from a light source section 10 arranged with a plurality of laser diodes in the subscanning direction MSD of a recording material, means for shifting the emitted laser beam and the recording material relatively in the main scanning direction, and means for controlling each diode to have an equal beam intensity depending on the beam intensity of each laser beam measured by means for measuring the beam intensity of each laser emitted from the plurality of laser diodes wherein an ND filter regulation means for shifting the intensity of exposure of all laser beams emitted from the plurality of laser diodes is disposed in the vicinity of a regulation plane CS.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a light source unit in which a plurality of laser diodes are aligned, a beam alignment optical system for aligning laser beams emitted from the plurality of laser diodes on a recording material in a sub-scanning direction, and The present invention relates to an image recording apparatus having a moving means for relatively moving a laser beam emitted from a plurality of laser diodes and the recording material in a main scanning direction.

[0002]

2. Description of the Related Art A light source unit in which a plurality of laser diodes are aligned, a beam alignment optical system in which laser beams emitted from the plurality of laser diodes are aligned in a sub-scanning direction on a recording material, and light emitted from the plurality of laser diodes. Conventionally, in an image recording apparatus having a moving means for relatively moving the laser beam and the recording material in the main scanning direction, the intensity of the laser beam is adjusted by controlling a current flowing through a laser diode. Was.

[0003]

However, in such an image recording apparatus, the intensity of each laser beam is adjusted to be equal, and the exposure intensity of all laser beams emitted from a plurality of laser diodes is adjusted. It is necessary to control both the current and the current flowing through the laser diode. It is not necessary to frequently adjust the intensity of each laser beam to be equal, but shifting the exposure intensity of all laser beams emitted from multiple laser diodes changes the tone reproduction of the output image. Must be performed when the recording material is changed or when the recording material is changed.

[0004] However, the relationship between the current and the amount of light emission of the laser diode is not proportional, and the relationship between the current and the amount of light emission differs depending on each laser diode.
Since the relationship between the current and the amount of light emission changes differently depending on the individual laser diode over time, a measuring means for measuring the beam intensity of each laser beam emitted from a plurality of laser diodes is provided to change the tone reproduction of the output image. Frequently, or when changing the recording material,
It has been necessary to adjust the current flowing through each of the plurality of laser diodes in accordance with the beam intensity of each laser beam measured by the measuring means, which took time.

An object of the first and second aspects of the present invention is to solve the above-mentioned problems, such as changing the tone reproduction of an output image that needs to be frequently performed, changing the recording material, and the like. In some cases, for example, it is possible to easily and stably shift the exposure intensity of all the laser beams emitted from a plurality of laser diodes in a short time.

In addition, it has been common practice to measure the beam intensity of the laser beam from each laser diode and adjust the current flowing through each of the plurality of laser diodes, with the trouble of the optical system.

However, in this case, only the variation of the beam intensity caused by the variation of the emission intensity of the laser diode with the passage of time can be adjusted, and the variation of the beam intensity caused by the change of the optical axis cannot be adjusted.

A third object of the present invention is to satisfactorily correct not only the variation of the light emission intensity of the laser diode with the passage of time but also the variation of the beam intensity of each laser beam including the variation of the beam intensity due to a change in the optical axis. Is to be able to do it.

In the conventional apparatus, it is necessary to match the recording position of the laser beam from each laser diode in the main scanning direction in order to prevent the recording position on the recording material from shifting. However, for this reason, high-precision adjustment is required for each device before installation or due to use over time.

A fourth object of the present invention is to provide a laser diode having a plurality of laser diodes, the recording positions of which are shifted on the recording material in the main scanning direction, even if the mounting accuracy of each laser diode is not high, such as the environment and the aging. Therefore, it is possible to satisfactorily correct the influence of the shift of the recording position of the laser beam emitted from each laser diode in the main scanning direction due to the optical axis shift due to the above, and to achieve good recording.

[0011]

The above object of the present invention can be attained by all the matters for specifying the invention described in the claims. Hereinafter, each claim will be described. However, items that are the same as those described in the cited items may be omitted. In each claim, it is needless to say that one or a plurality of members may also serve as a plurality of elements of the present invention unless otherwise specified, and a plurality of members correspond to one element of the present invention. Needless to say, this may be done.

(1) A light source unit in which a plurality of laser diodes are aligned, and a beam alignment optical system for aligning laser beams emitted from the plurality of laser diodes on a recording surface of a recording material in a sub-scanning direction. A moving unit that relatively moves the laser beam and the recording material emitted from the plurality of laser diodes in the main scanning direction, and a measuring unit that measures the beam intensity of each laser beam emitted from the plurality of laser diodes. A laser diode control unit that controls each of the plurality of laser diodes so that the beam intensity of each laser beam is equal according to the beam intensity of each laser beam measured by the measurement unit. A recording device, comprising: a laser beam emitted from the plurality of laser diodes by a filter. The image recording apparatus characterized by comprising a filter adjusting means for shifting all exposure intensity. According to the invention described in claim 1, the intensities of the infrequent laser beams can be made uniform by controlling the current flowing through each of the plurality of laser diodes, and can be adjusted with high accuracy. Shifting the beam intensities of all the laser beams emitted from the laser diode can be easily adjusted because it is performed by a filter.

[Claim 2] "The filter adjusting means comprises:
The exposure intensity of all the laser beams emitted from the plurality of laser diodes is shifted by selectively inserting and removing a plurality of filters having different densities into and from the optical path of the laser beam. The image recording apparatus as described in the above. According to the second aspect of the present invention, it is possible to shift the beam intensity of all the laser beams emitted from a plurality of laser diodes that are frequently performed to a plurality of stages.

[Claim 3] "The filter adjusting means comprises:
2. The method according to claim 1, further comprising an optical wedge filter, wherein an exposure intensity of all laser beams emitted from the plurality of laser diodes is shifted by changing a beam incident position on the optical wedge filter. The image recording apparatus as described in the above. According to the third aspect of the present invention, it is possible to shift the beam intensity of all the laser beams emitted from a plurality of laser diodes, which are frequently performed, in a plurality of steps or continuously by the filter adjustment means having a small and simple structure. it can.

(4) The optical wedge filter is a disk-type optical wedge filter, and the beam incident position on the disk-type optical wedge filter is in the same radial direction as the disk-type optical wedge filter. 4. The image recording apparatus according to claim 3, wherein the laser beams emitted from the plurality of laser diodes are incident on the optical wedge filter. According to the invention described in claim 4, the beam intensity of each laser beam emitted from the plurality of laser diodes can be shifted by exactly the same amount.

[5] The image according to [1], further comprising: beam converging means for converging the incident positions of all the laser beams emitted from the plurality of laser diodes to the filter at substantially one point. Recording device. According to the invention as set forth in claim 5, the degree of freedom of the positional relationship between the laser beam and the filter is increased, the filter is not affected by the unevenness of the filter, and the density varies depending on the position, such as an optical wedge filter. Even in this case, the beam intensity of each laser beam emitted from a plurality of laser diodes can be shifted by exactly the same amount.

(6) A light source unit in which a plurality of laser diodes are aligned, and a beam alignment optical system for aligning laser beams emitted from the plurality of laser diodes on a recording surface of a recording material in a sub-scanning direction; A moving unit that relatively moves the laser beam and the recording material emitted from the plurality of laser diodes in the main scanning direction, and a measuring unit that measures the beam intensity of each laser beam emitted from the plurality of laser diodes. A laser diode control unit that controls each of the plurality of laser diodes so that the beam intensity of each laser beam is equal according to the beam intensity of each laser beam measured by the measurement unit. A recording device, wherein a laser beam emitted from the plurality of laser diodes by a polarizer The image recording apparatus characterized by including a polarizer adjustment means for shifting the exposure intensity of Te. According to the invention described in claim 6, the intensities of the infrequent laser beams can be made uniform by controlling the current flowing through each of the plurality of laser diodes, and can be adjusted with high accuracy. Shifting the beam intensities of all the laser beams emitted from the laser diode is performed by a polarizer, so that it can be easily adjusted.

[Claim 7] [The invention has a beam converging means for converging the incident positions of all the laser beams emitted from the plurality of laser diodes on the polarizer to substantially one point. Image recording device. According to the invention described in claim 7, the degree of freedom of the positional relationship between the laser beam and the polarizer is increased, and the beam intensity of each laser beam emitted from the plurality of laser diodes is not affected by the unevenness of the polarizer. Can be shifted by exactly the same amount.

[Claim 8] "A light source section in which a plurality of laser diodes are aligned, and a beam alignment optical system for aligning laser beams emitted from the plurality of laser diodes on a recording surface of a recording material in a sub-scanning direction. A moving unit that relatively moves the laser beam and the recording material emitted from the plurality of laser diodes in the main scanning direction, and a measuring unit that measures the beam intensity of each laser beam emitted from the plurality of laser diodes. A laser diode control unit that controls each laser diode of the plurality of laser diodes according to the beam intensity of each laser beam measured by the measurement unit, and an image recording apparatus, wherein the measurement unit is With a light-receiving element that can move relatively to a position where it can receive the laser beam emitted from the beam alignment optical system An image characterized by receiving each laser beam emitted from the beam alignment optical system emitted from the plurality of laser diodes and measuring the beam intensity of each laser beam emitted from the plurality of laser diodes. Recording device. According to the invention described in claim 8, it is possible to favorably correct not only the fluctuation of the light emission intensity of the laser diode with the passage of time but also the fluctuation of the beam intensity of each laser beam including the fluctuation of the beam intensity due to a change in the optical axis. .

[9] The image recording apparatus according to [8], wherein the light receiving element is movable relative to a recording surface of the recording material by the laser beam. According to the invention described in claim 9, the beam intensity of each laser beam on the recording surface of the recording material can be directly detected, and the fluctuation of the beam intensity of each laser beam can be corrected well.

[Claim 10] "A light source unit in which a plurality of laser diodes are aligned, and a beam alignment optical system for aligning laser beams emitted from the plurality of laser diodes on a recording surface of a recording material in a sub-scanning direction. Moving means for relatively moving the laser beam emitted from the plurality of laser diodes and the recording material in the main scanning direction, comprising: And an emission timing control means for delaying the emission timing of each laser diode. According to the invention as set forth in claim 10, even if the mounting accuracy of each laser diode is not high enough to shift the recording position of each laser beam of the plurality of laser diodes on the recording surface of the recording material in the sub-scanning direction, Since the light emission timing of the laser diode can be delayed for each laser diode individually, the influence of the shift in the main scanning direction of the recording position of the laser beam emitted from each laser diode due to the optical axis shift due to the environment, aging, etc. Can be satisfactorily corrected and satisfactorily recorded.

(11) A recording position detector for detecting a recording position of each laser beam emitted from the plurality of laser diodes, the recording position detector being movable relative to a recording surface of the recording material by the laser beam. Wherein the light emission timing control means individually controls each laser diode of the plurality of laser diodes according to a recording position of a laser beam emitted from each laser diode detected by the recording position detector. The image recording apparatus according to claim 10, wherein the light emission timing of the diode is delayed. According to the invention of claim 11, the recording position of the laser beam emitted from each laser diode is automatically measured, and the recording position of each laser diode is measured according to the measured recording position of the laser beam emitted from each laser diode. The amount of delay in the light emission timing can be determined and controlled, so that the effect of the shift in the main scanning direction of the recording position of the laser beam emitted from each laser diode due to the optical axis shift due to the environment, aging, etc. is automatically corrected. The recording can be performed well with less trouble for maintaining the quality of the recorded image.

[Explanation of Terms and Others] A polarizer is a broadly-defined polarizer in "Optoelectronics Glossary" issued by Ohm, and is an element that converts natural light into linearly polarized light, circularly polarized light, or elliptically polarized light. , Polarizing prism, polarizing plate,
Pile type polarizers and the like can be mentioned.

The term "optical wedge" used in the present invention is a concept including "optical wedge" described in "Photographic Dictionary" edited by the Photographic Committee of the Photographic Society of Japan issued by Photographic Industry Publishing Company, and is a distance in a predetermined direction. It is a plate-shaped light absorber manufactured to change the optical density in a stepwise or continuous manner, but since the intensity of the laser beam whose wavelength is substantially constant is changed, the light absorption depends on the wavelength. It does not need to be a substance that does not change. Here, the predetermined direction may be a rotation direction, a linear direction, or another direction.

The "recording material" in the present invention is a material on which an image such as a latent image or a visible image is formed by irradiating a laser beam, and may be a photosensitive material sensitized by the laser beam. The material may be a material whose plate surface is formed by ablation by irradiating a laser beam, or may be another material.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, one example of a specific example of the present invention will be shown as an embodiment and an example, but the present invention is not limited to this. In the embodiments and examples, certain terms and the like are explicitly stated, but they show preferred examples of the present invention, and do not limit the meaning or technical scope of the terms of the present invention.

Embodiment 1 The image recording apparatus of this embodiment is an apparatus for recording a latent image on a photographic film for plate making, which is a silver halide monochrome photographic photosensitive material provided with a photosensitive layer sensitive to red light. This device records a latent image on a photographic paper by simultaneously generating a plurality of laser beams of light and irradiating the photographic paper moving in the main scanning direction while aligning the laser beams in the sub-scanning direction MSD. FIG. 1 is a schematic configuration diagram of the image recording apparatus of the present embodiment. Hereinafter, the image recording apparatus of the present embodiment will be described with reference to FIG.

The optical unit 1 has a plurality (for example, 10
And a plurality of laser beams emitted from the plurality of laser diodes of the light source unit 10 on the recording surface of a photographic film for plate making wound around the drum 2. In the sub-scanning direction M
A beam alignment optical system 20 for aligning with the SD is provided.

The drum 2 is used to wind and fix a photographic film for plate making. When an image is recorded, the drum 2 is rotated at a constant speed to thereby form a plurality of laser diodes LD.
10 to move a plurality of laser beams emitted from the LD 19 and the photographic film for plate making in the main scanning direction relatively.

The optical unit 1 is moved in the sub-scanning direction M
The optical unit 1 moves in the sub-scanning direction MSD with respect to the drum 2 so that a latent image is recorded on the entire photographic film wound around the drum 2 and fixed. is there.

Further, the light receiving element 3 is provided on the same plane as the recording surface of the photographic film for plate making using a plurality of laser beams. Then, the optical unit 1 moves in the sub-scanning direction M
By moving to the SD, a plurality of laser beams enter the light receiving element 3 so that the light receiving element 3
The beam intensity of each laser beam emitted from the plurality of laser diodes and emitted from the beam alignment optical system 20 is measured.

The laser diode controller 4 shown in FIG. 2, which is a block diagram of the image recording apparatus of the present embodiment,
According to the beam intensity of each laser beam measured by the light receiving element 3, each laser diode of the plurality of laser diodes of the light source unit 10 is controlled so that the beam intensity of each laser beam becomes equal.

The light source unit 10 is provided with a plurality of laser diodes LD10 to LD19 arranged at predetermined intervals. And a plurality of laser diodes L
D10 to LD19 are arranged so as to irradiate a laser beam toward a center point CP in front of the lens 21.

The beam alignment optical system 20 includes the following. The lens 21 makes the plurality of laser beams emitted from the plurality of laser diodes parallel. Then, the mirror 22 reflects the plurality of laser beams parallelized by the lens 21 at right angles, and further reflects the plurality of laser beams at right angles to the converging lens group 24. Let it. Then, the plurality of laser beams incident on the converging lens group 24 are adjusted to the adjustment surface C.
S is converged to one point. Then, the plurality of laser beams that have passed through the adjustment surface CS enter the reduction optical lens group 25. Then, the reduction optical lens group 25 reduces the plurality of incident laser beams on the recording surface RS on the recording material wound around the drum 2 to form an image.
Then, the plurality of laser beams emitted from the reduction optical lens group 25 enter the cylindrical lens 26. The cylindrical lens 26 is a lens having a refractive power only in the main scanning direction. The cylindrical lens 26 converges so that the positions of the plurality of laser beams in the main scanning direction on the recording surface RS are constant, and the plurality of laser beams Are aligned in the sub-scanning direction MSD on the recording surface RS as shown in FIG.

FIG. 3 is a view of the recording surface RS as viewed from the front. A plurality of laser beams having a beam diameter BR are aligned in the sub-scanning direction MSD at the beam pitch BP in the sub-scanning direction MSD. Record the latent image. And drum 2
During one rotation, the optical unit 1 moves the drum 2 in the sub-scanning direction MSD by a constant moving amount FQ (= 10 × B
P) By moving, the latent image is recorded evenly on the entire photographic film for plate making wound and fixed around the drum 2. As specific values of the beam diameter BR, the beam pitch BP, and the movement amount FQ, for example, the beam diameter BR is 10.6 μm, and the beam pitch BP is also 10.6 μm.
m, the moving amount FQ is preferably 106 μm.

Further, an exposure intensity adjusting section 5 is provided near the adjusting surface CS. FIG. 4 is a schematic view showing the vicinity of the exposure intensity adjusting unit 5. The exposure intensity adjusting unit 5 is provided with a plurality of ND filters 51 to 55 having different densities so that the ND filters 51 and 55 can be inserted into and removed from the laser beam optical path by filter driving members 56 and 57. The ND filters 51 to 55 are achromatic filters. The ND filter 51 is ND-8 and has a density of 2.4, and the ND filter 52 is ND-4 and has a density of 1.
2. The ND filter 53 has a density of 0.6, ND-2 and ND-2.
The filter 54 has an ND-1 density of 0.3, and the ND filter 55 has an ND-1 / 2 density of 0.15.

The laser diode controller 4 shown in FIG. 2, which is a block diagram of the image recording apparatus of the present embodiment,
The exposure intensity adjustment amount is determined according to the beam intensity of each laser beam measured by the light receiving element 3 and the sensitivity of the recording material wound and fixed on the drum 2, and the exposure intensity adjustment amount is determined according to the determined exposure intensity adjustment amount. The exposure intensity adjustment unit 5 shifts the exposure intensity of all the laser beams emitted from the plurality of laser diodes.

Here, the laser diode control section 4 controls the plurality of laser diodes of the light source section 10 in accordance with the beam intensity of each laser beam measured by the light receiving element 3 so that the beam intensity of each laser beam becomes equal. Each laser diode is controlled, and an exposure intensity adjustment amount is determined according to the beam intensity of each laser beam measured by the light receiving element 3 and the sensitivity of the recording material wound and fixed on the drum 2.
According to the obtained exposure intensity adjustment amount, the exposure intensity adjustment unit 5
Next, calculation for shifting the exposure intensity of all laser beams emitted from a plurality of laser diodes will be described.

In the laser diode control unit 4, a standard beam intensity SBI, which is a standard beam intensity, is set in advance. Then, assuming that the beam intensities of the laser beams emitted from the plurality of laser diodes LD10 to LD19 measured by the light receiving element 3 are BI10 to BI19, an arithmetic average value MBI of these beam intensities BI10 to BI19 is obtained. And the arithmetic average value M of the beam intensity
From the BI and the standard beam intensity SBI, the exposure intensity adjustment amount correction amount ΔRPI and the target beam intensity TBI are obtained by the following equation.

ΔRPI = | 2 × log ₂ (MBI / SBI) | TBI = SBI × {2} ΔRPI And the measured beam intensity BI1 of each laser beam
0 to BI19 and the target beam intensity TBI, change and adjust the value of the current flowing through the laser diode, and again
The laser beams are emitted from the plurality of laser diodes LD10 to LD19, and the measurement of the beam intensities BI10 to BI19 of the laser beams emitted from the plurality of laser diodes LD10 to LD19 by the light receiving element 3 is repeated. Beam intensity BI10-BI
19 and the target beam intensity TBI are substantially equal,
The current value I flowing through each of the laser diodes LD10 to LD19
10 to I19 are obtained and set.

Further, the laser diode control unit 4 has a film type exposure intensity adjustment unique to each type of a plurality of types of plate-making photographic film capable of recording a latent image by the image recording apparatus of the present embodiment in advance. The quantity KRPI is preset. Then, the laser diode control unit 4 reads the film type exposure intensity adjustment amount KRPI corresponding to the type of the stencil film for recording the latent image. Then, the laser diode control unit 4 calculates the exposure intensity adjustment amount RPI by adding the exposure intensity adjustment amount correction amount ΔRPI and the film type exposure intensity adjustment amount KRPI.

RPI = KRPI + ΔRPI Then, the laser diode control unit 4 transmits the obtained exposure intensity adjustment amount RPI to the exposure intensity adjustment unit 5 as binary numerical data. Then, the exposure intensity adjustment unit 5 controls insertion / removal of the filters 51 to 55 into / from the laser beam optical path according to the transmitted exposure intensity adjustment amount RPI. That is,
The first digit, which is the least significant digit of the exposure intensity adjustment amount RPI, is
If “1”, the filter 55 is inserted into the laser beam optical path, and if “0”, the filter 55 is not inserted into the laser beam optical path. The second digit of the exposure intensity adjustment amount RPI is
If “1”, the filter 54 is inserted into the laser beam optical path, and if “0”, the filter 54 is not inserted into the laser beam optical path. The third digit of the exposure intensity adjustment amount RPI is
If “1”, the filter 53 is inserted into the laser beam optical path, and if “0”, the filter 53 is not inserted into the laser beam optical path. The fourth digit of the exposure intensity adjustment amount RPI is
If “1”, the filter 52 is inserted into the laser beam optical path, and if “0”, the filter 52 is not inserted into the laser beam optical path. The fifth digit of the exposure intensity adjustment amount RPI is
If “1”, the filter 51 is inserted into the laser beam optical path, and if “0”, the filter 51 is not inserted into the laser beam optical path.

As a result, the intensities of the infrequent laser beams can be made uniform by the plurality of laser diodes LD1.
By controlling the current flowing through each of the laser diodes LD0 to LD19, the adjustment can be performed with high precision. Shifting the beam intensities of all the laser beams emitted from the plurality of laser diodes LD10 to LD19, which are frequently performed, can be performed by the filters 51 to Since adjustment is performed by 55, adjustment can be made easily. Further, by selectively inserting and removing a plurality of filters 51 to 55 having different densities in the optical path of the laser beam, the exposure intensity of all the laser beams emitted from the plurality of laser diodes LD10 to LD19 is shifted. The beam intensity of all the laser beams emitted from the diodes LD10 to LD19 can be shifted to a plurality of stages.

Also, a plurality of laser diodes LD10
All the laser beams emitted from the LD 19 are converged to a substantially single point by the converging lens group 24, and near the convergent point,
Since a plurality of filters 51 to 55 having different densities are inserted and removed, the degree of freedom of the positional relationship between the laser beam and the filters 51 to 55 is increased, and a plurality of lasers are not affected by unevenness of the filters 51 to 55. Diode LD10-LD
The beam intensity of each laser beam emitted from the light source 19 can be shifted by exactly the same amount.

Each of the laser beams emitted from the plurality of laser diodes LD10 to LD19 is received by a light receiving element movable relative to the recording surface of the photographic film for plate making by the laser beam.
Since the beam intensity BI10-BI19 of each laser beam emitted from D10-LD19 is measured, not only the emission intensity of the laser diodes LD10-LD19 over time, but also the beam intensity variation due to optical axis change and the like. Beam intensity BI10 of each laser beam including
To BI19 can be satisfactorily corrected.

The light receiving element 3 is capable of detecting a two-dimensional light quantity distribution on the recording surface RS like a two-dimensional CCD image pickup device. When relatively moved, the recording position of each laser beam emitted from the plurality of laser diodes LD10 to LD19 can be detected.

The recording position of the laser beam is shown in FIG.
It is preferable that the recording surface RS is aligned in the sub-scanning direction as shown in FIG. 5, but actually, regardless of the alignment effect of the cylindrical lens 26, as shown in FIG. In addition, the recording position of each laser beam may be shifted in the main scanning direction.

The light receiving element 3 detects the recording positions BC10 to BC19 of the laser beams emitted from the respective laser diodes LD10 to LD19, and the detected recording positions BC10 to BC19 are shown in FIG. This is transmitted to the timing control unit 6. Then, the light emission timing control unit 6 determines the recording position (FIG. 5) that is the most upstream in the drum rotation direction from the recording positions BC10 to BC19.
In this case, a straight line extending from BC15) in the sub-scanning direction is set as a standard recording line SBL. Then, the light emission timing controller 6 calculates deviations ΔBC10 to ΔBC19 of the recording positions BC10 to BC19 from the standard recording line SBL, and calculates a plurality of laser diodes LD10 to Δ1010 to ΔBC19 based on the deviations ΔBC10 to ΔBC19 and the peripheral speed VD of the drum 2. For each laser diode of the LD 19, the delay time TR10 to TR19 is obtained by the following equation.

TRi = ΔBCi / VD (i = a natural number of 10 to 19) Then, the light emission timing control unit 6 converts the image signals input to each of the plurality of laser diodes LD10 to LD19 into a delay time TR10. The signal is input to the light source unit 10 after being delayed by TR19. Thereby, the light emission timing control unit 6 individually sets the recording positions BC10 to BC19 of the laser beams emitted from each laser diode detected by the light receiving element 3 for each laser diode.
, The light emission timing of each laser diode is delayed.

Thus, a plurality of laser diodes LD
Even if the mounting positions of the laser diodes LD10 to LD19 are not so high that the recording positions BC10 to BC19 of the laser beams of the laser beams 10 to LD19 on the recording material are shifted in the main scanning direction SSD, the laser beams are automatically emitted from the laser diodes. The recording positions BC10 to BC19 of the measured laser beams are measured, and the delay times TR10 to TR10 of the light emission timings of the respective laser diodes are determined according to the measured recording positions BC10 to BC19 of the laser beams emitted from the respective laser diodes.
19 can be determined and controlled, so that the light emission timing of the laser diode can be automatically and individually delayed for each laser diode. The influence of the deviation of the recording positions BC10 to BC19 of the laser beams in the main scanning direction SSD can be corrected well, and the trouble of maintaining the quality of the recorded image is reduced, and the recording can be performed well.

Embodiment 2 The image recording apparatus of the present embodiment is a modified embodiment in which the structure of the exposure intensity adjusting section 5 of the image recording apparatus of Embodiment 1 is changed. Hereinafter, all the differences from the first embodiment will be described.

FIG. 6 is a schematic diagram showing the vicinity of the exposure intensity adjusting unit 5 of the image recording apparatus of the present embodiment. Exposure intensity adjustment unit 5
Has an optical wedge filter 58 whose density continuously increases in proportion to the distance in the sub-scanning direction MSD. The optical wedge filter 58 is held movably on the adjustment surface CS in the sub-scanning direction MSD by the filter driving member 69, and is optically controlled in accordance with the exposure intensity adjustment amount input to the exposure intensity adjustment unit 5. The optical wedge filter 58 is driven to adjust the beam incident position on the optical wedge filter 58 so that the portion of the wedge filter 58 having the density corresponding to the exposure intensity adjustment amount becomes the beam incident position. Thus, the beam intensity of all the laser beams emitted from a plurality of laser diodes, which is frequently performed, can be continuously shifted by the exposure intensity adjusting unit 5 having a small and simple structure.

Further, the laser diode control section 4 controls the plurality of laser diodes of the light source section 10 in accordance with the beam intensity of each laser beam measured by the light receiving element 3 so that the beam intensity of each laser beam becomes equal. Each laser diode is controlled, and an exposure intensity adjustment amount is determined according to the beam intensity of each laser beam measured by the light receiving element 3 and the sensitivity of the recording material wound and fixed on the drum 2.
According to the obtained exposure intensity adjustment amount, the exposure intensity adjustment unit 5
In addition, a calculation for shifting the exposure intensity of all the laser beams emitted from a plurality of laser diodes is performed in the first embodiment.
Is different from

In the laser diode controller 4, a standard beam intensity SBI, which is a standard beam intensity, is set in advance. When the beam intensities of the respective laser beams emitted from the plurality of laser diodes LD10 to LD19 measured by the light receiving element 3 and emitted from the beam alignment optical system 20 are defined as BI10 to BI19, the arithmetic average of these beam intensities BI10 to BI19 is assumed. Determine the value MBI. Then, based on the arithmetic average value MBI of the beam intensity and the standard beam intensity SBI, the exposure intensity adjustment amount correction amount ΔR
The PI and the target beam intensity TBI are obtained.

ΔRPI = 2 × log ₂ (MBI / SBI) TBI = MBI And the measured beam intensity BI1 of each laser beam
0 to BI19 and the target beam intensity TBI, change and adjust the value of the current flowing through the laser diode, and again
The laser beams are emitted from the plurality of laser diodes LD10 to LD19, and the measurement of the beam intensities BI10 to BI19 of the laser beams emitted from the plurality of laser diodes LD10 to LD19 by the light receiving element 3 is repeated. Beam intensity BI10-BI
19 and the target beam intensity TBI are substantially equal,
The current value I flowing through each of the laser diodes LD10 to LD19
10 to I19 are obtained and set.

Further, the laser diode control unit 4 has a plurality of types of plate-making photographic films capable of recording a latent image in advance by the image recording apparatus of the present embodiment. The quantity KRPI is preset. Then, the laser diode control unit 4 reads the film type exposure intensity adjustment amount KRPI corresponding to the type of the stencil film for recording the latent image. Then, the laser diode control unit 4 calculates the exposure intensity adjustment amount RPI by adding the exposure intensity adjustment amount correction amount ΔRPI and the film type exposure intensity adjustment amount KRPI.

RPI = KRPI + ΔRPI Then, the laser diode control unit 4 transmits the obtained exposure intensity adjustment amount RPI to the exposure intensity adjustment unit 5 as binary numerical data. Then, the exposure intensity adjustment unit 5 determines the optical wedge filter 5 according to the transmitted exposure intensity adjustment amount RPI.
8 is controlled to be inserted into the optical path of the laser beam.

Further, a plurality of laser diodes LD10
All the laser beams emitted from the LD 19 are converged to substantially one point by the converging lens group 24, and the optical wedge filter 58 is located at this convergent point, so that the degree of freedom of the positional relationship between the laser beam and the optical wedge filter 58 increases. Further, the beam intensity of each laser beam emitted from the plurality of laser diodes LD10 to LD19 can be shifted exactly by the same amount without being affected by the unevenness of the optical wedge filter 58.

Embodiment 3 An image recording apparatus according to the present embodiment is a modification in which the optical wedge filter 58 of the image recording apparatus according to Embodiment 2 is changed to a disk-type optical wedge filter 60. Hereinafter, all the differences from the second embodiment will be described.

FIG. 7 is a view of the disc type optical wedge filter 60 of the image recording apparatus according to the present embodiment as viewed from the converging lens group 24 side. FIG. 8 is a schematic configuration diagram near the exposure intensity adjusting unit 5 of the image recording apparatus of the present embodiment. The disk-type optical wedge filter 60 of the present embodiment is an optical wedge filter in which the density continuously increases in proportion to the rotation angle in the rotation direction SD (in FIG. 7, there is no expression power of light and shade due to the electronic application. Although it is intermittent). The disc-type optical wedge filter 60 is rotatably held on the adjustment surface CS in the rotation direction SD by the filter driving member 61, and according to the exposure intensity adjustment amount input to the exposure intensity adjustment unit 5, Disk type optical wedge filter 6
The disk-type optical wedge filter 60 is driven so that the portion of the density corresponding to the exposure intensity adjustment amount of 0 is the beam incident position BIP.
The beam incident position BIP to 0 is adjusted. This allows
The exposure intensity adjustment unit 5 having a small and simple structure can continuously shift the beam intensity of all the laser beams emitted from a plurality of laser diodes, which are frequently performed.

The converging lens group 24 converges the incident position BIP of all the laser beams emitted from the plurality of laser diodes LD10 to LD19 to the disk-type optical wedge filter 60 at substantially one point, so that the laser beam and the disk-type optical wedge are converged. The degree of freedom of the positional relationship with the filter 60 is increased, and the beam intensity of each laser beam emitted from a plurality of laser diodes is shifted by exactly the same amount without being affected by the unevenness of the disk-type optical wedge filter 60. Can be.

Embodiment 4 The image recording apparatus of this embodiment is a modification of the image recording apparatus of Embodiment 3 in which the disk-type optical wedge filter 60 is changed to a disk-type polarization filter. Hereinafter, all the differences from the second embodiment will be described.

The direction of the transmitted polarized light of the disk-type polarizing filter changes according to the rotation angle in the rotation direction SD. The laser beam is polarized because it is coherent light. Then, the light source unit 10 is controlled so that all of the laser beams emitted from the plurality of laser diodes LD10 to LD19 provided in the light source unit 10 have the same polarization.
Are arranged with a plurality of laser diodes LD10 to LD19.

Therefore, in accordance with the exposure intensity adjustment amount input to the exposure intensity adjustment unit 5, the disk-type polarization filter is adjusted so that the rotation angle of the disk-type polarizing filter is oriented in the direction of transmittance corresponding to the exposure intensity adjustment amount. The filter is driven to adjust the beam incident position BIP on the disk-type polarizing filter.
Thereby, the exposure intensity adjusting unit 5 having a small and simple structure has:
It is possible to continuously shift the beam intensity of all the laser beams emitted from a plurality of laser diodes that are frequently performed.

The positions BIP of the laser beams emitted from the plurality of laser diodes LD10 to LD19 by the converging lens group 24 to the disk-type polarizing filter.
Is substantially converged to one point, the degree of freedom of the positional relationship between the laser beam and the disk-type polarizing filter increases, and the laser beam emitted from a plurality of laser diodes is not affected by the unevenness of the disk-type polarizing filter. The beam intensity can be shifted by exactly the same amount.

Embodiment 5 The image recording apparatus of the present embodiment is a method for forming a latent image on a photographic paper, which is a silver halide color photographic material provided with a photosensitive layer sensitive to each of green light, red light and infrared light. This is a device for recording, which simultaneously generates a plurality of (for example, 10) laser beams for each of green light, red light and infrared light, and moves the photographic paper moving in the main scanning direction in the sub-scanning direction MSD. This is a device that records a latent image on photographic paper by aligning and irradiating it. FIG. 9 is a schematic configuration diagram of the image recording apparatus of the present embodiment. Hereinafter, the image recording apparatus of the present embodiment will be described with reference to FIG.

The optical unit 1 is provided with an infrared light source unit 70 in which a plurality of laser diodes emitting infrared light are aligned, and a plurality of laser diodes emitting red light are aligned. A red light source section 80,
A green light source section 90 that emits a plurality of laser beams, a plurality of laser beams emitted from a plurality of laser diodes of the infrared light source section 70, A plurality of laser beams emitted from a plurality of laser diodes of the light source unit 80 and a plurality of laser beams emitted from the green light source unit 90 are put on a recording surface of a photographic film for plate making wound around the drum 2. Beam alignment optical system 3 for aligning in the sub-scanning direction MSD
0 is provided.

The drum 2 is used to wind and fix a photographic film for plate making. When an image is recorded, the drum 2 rotates at a constant speed to thereby produce a plurality of laser beams emitted from the infrared light source 70 and a red light source. The plurality of laser beams emitted from the green light source unit 90 and the plurality of laser beams emitted from the green light source unit 90 are relatively moved in the main scanning direction.

The optical unit 1 moves in the sub-scanning direction M
The optical unit 1 moves in the sub-scanning direction MSD with respect to the drum 2 so that a latent image is recorded on the entire photographic film wound around the drum 2 and fixed. is there.

The light receiving element 3 is provided on the same plane as the recording surface of the photographic film for plate making using these laser beams. Then, the optical unit 1 moves in the sub-scanning direction M
By moving to SD, these laser beams are made to enter the light receiving element 3, so that the light receiving element 3 includes a plurality of laser beams emitted from the infrared light source 70 and a red light source 8.
The beam intensity of each of the plurality of laser beams emitted from 0 and the plurality of laser beams emitted from the green light source unit 90 is measured.

The laser diode control unit 4 shown in FIG. 2, which is a block diagram of the image recording apparatus of this embodiment,
In accordance with the beam intensity of each laser beam emitted from the infrared light source unit 70 measured by the light receiving element 3, the infrared light source unit 70 is set so that the beam intensity of each laser beam becomes equal.
Of the plurality of laser diodes, and the red light source unit 80 measured by the light receiving element 3.
Depending on the beam intensity of each laser beam emitted from
Each of the plurality of laser diodes of the red light source unit 80 is controlled so that the beam intensity of each laser beam becomes equal. In addition, the green light source unit 90 includes one He-
This control is not performed because the laser beam is divided into a plurality of laser beams having a uniform light amount from the Ne laser.

In the infrared light source section 70, a plurality of laser diodes LD70 to LD79 are provided at predetermined intervals. The plurality of laser diodes LD70 to LD79 are connected to a center point C in front of the lens 31.
It is arranged to irradiate a laser beam toward P.

In the red light source section 80, a plurality of laser diodes LD80 to LD89 are provided at predetermined intervals. The plurality of laser diodes LD80 to LD89 are connected to a center point C in front of the lens 31.
It is arranged to irradiate a laser beam toward P.

In the green light source section 90, the He—Ne laser 91 emits a laser beam of 544 nm and makes it enter the beam separator 92. The beam separator 92 splits the incident laser beam into a plurality of laser beams. The cylindrical lens 93 reduces variations in the direction in the main scanning direction. Then, a plurality of laser beams are made incident on the acousto-optic element 94. Then, the acousto-optic device 94 drives the acousto-optic device 94 in accordance with the image signal input to the green light source unit 90, and controls ON / OFF of each laser beam. Then, the ON laser beam passes through the cylindrical lens 95 to emit a plurality of laser beams.

The beam alignment optical system 30 includes the following. The lens 31 makes the plurality of laser beams emitted from the plurality of laser diodes LD70 to LD79 of the infrared light source unit 70 parallel to each other. Then, the mirror 32 reflects the plurality of laser beams parallelized by the lens 31 at right angles, and further, the dichroic mirror 37 reflects the plurality of laser beams at right angles to the converging lens group 38. Make it incident. Also, the lens 33
Are a plurality of laser diodes LD8 of the red light source section 80.
A plurality of laser beams emitted from LD 0 to LD 89 are made parallel to each other. Then, the mirror 34 reflects the plurality of laser beams parallel to each other by the lens 33 at right angles, and further passes through the dichroic mirrors 36 and 37 to enter the converging lens group 38. The plurality of laser beams emitted from the green light source unit 90 are
Are reflected at a right angle, reflected at a right angle by a dichroic mirror 36, passed through a dichroic mirror 37, and incident on a converging lens group 38.

Then, these laser beams incident on the converging lens group 38 are converged on one point of the adjustment surface CS. Then, the plurality of laser beams that have passed through the adjustment surface CS enter the reduction optical lens group 39. Then, the reduction optical lens group 39 reduces these incident laser beams on the recording surface RS on the recording material wound around the drum 2 to form an image. Then, the plurality of laser beams emitted from the reduction optical lens group 39 enter the cylindrical lens 40. And the cylindrical lens 4
0 is a lens having a refractive power only in the main scanning direction,
These laser beams are converged so as to keep the position in the main scanning direction on the recording surface RS constant, and a plurality of laser beams are aligned in the sub scanning direction MSD on the recording surface RS as shown in FIG. Let it.

FIG. 3 is a view of the recording surface RS as viewed from the front. A plurality of laser beams emitted from the red light source unit 70, a plurality of laser beams emitted from the infrared light source unit 80, and a green light source unit 90 are shown. Are overlapped with each other, and a plurality of laser beams having a beam diameter BR in the sub-scanning direction MSD are formed at a beam pitch BP in the sub-scanning direction M.
A latent image is recorded on a recording material by aligning with the SD. During the rotation of the drum 2 by one rotation, the optical unit 1 moves the drum 2 in the sub-scanning direction MSD by a constant moving amount FQ.
By moving (= 10 × BP), the latent image is recorded evenly on the entire stencil film fixed and wound around the drum 2. The order of the beam diameter BR and the beam pitch BP is about 1 to 100 μm.

The exposure intensity adjusting section 5 is provided near the adjusting surface CS. The exposure intensity adjustment unit 5 of the image recording apparatus of the present embodiment is different from the exposure intensity adjustment unit 5 of the second embodiment.
Is the same as

Next, the laser light source 70 and the red light source 70 are controlled by the laser diode controller 4 so that the beam intensity of each laser beam becomes equal according to the beam intensity of each laser beam measured by the light receiving element 3. Each of the plurality of laser diodes of the unit 80 is controlled, and according to the beam intensity of each laser beam measured by the light receiving element 3 and the sensitivity of the recording material wound and fixed on the drum 2,
An exposure intensity adjustment amount is obtained, and the exposure intensity adjustment unit 5 supplies the exposure intensity of all the laser beams emitted from the infrared light source unit 70, the red light source unit 80, and the green light source unit 90 in accordance with the obtained exposure intensity adjustment amount. The operation for shifting is described.

First, if the beam intensity of each green laser beam measured by the light receiving element 3 varies, the beam separator 92 is adjusted. Then, the adjustment is performed until there is no variation in the beam intensity of each of the measured green laser beams. Then, the arithmetic average value of the beam intensities of the green laser beams from which the dispersion has been eliminated is defined as MBIG. The laser diode control unit 4 includes a green standard beam intensity SBIG, which is a standard green laser beam intensity, a red standard beam intensity SBIR, which is a standard red laser beam intensity, and a standard The infrared standard beam intensity SBIIR, which is the beam intensity of the infrared laser beam, is set in advance. And
The beam intensity of each of the infrared and red laser beams measured by the light receiving element 3 is represented by BI70 to BI79, BI80 to B80.
Assuming that I89, arithmetic average values MBIIR and MBIR of these beam intensities are obtained for each of infrared and red. And
The arithmetic mean values of these beam intensities MBIG, MBIR,
From the MBIIR, the green standard beam intensity SBIG, the red standard beam intensity SBIR, and the infrared standard beam intensity SBIIR, the exposure intensity adjustment amount correction amount ΔRPI, the green target beam intensity TBIG, and the red target beam intensity TBI are calculated by the following equations.
R and the infrared target beam intensity TBIIR are obtained.

ΔRPI = 2 × log ₂ (MBIG / SBIG) TBIG = MBIG TBIR = SBIR × √2∧ΔRPI TBIIR = SBIIR × √2∧ΔRPI Then, the measured beam intensities BI80 to BI89 of each red laser beam The current flowing through each laser diode is changed and adjusted according to the ratio with the red target beam intensity TBIR, and the plurality of laser diodes LD80 to LD8 are again adjusted.
9 and repeatedly measure the beam intensities BI80 to BI89 of the respective laser beams emitted from the plurality of laser diodes LD80 to LD89 by the light receiving element 3, thereby obtaining the beam intensity B of each laser beam.
Each of the laser diodes LD80 to LD80 is set so that I80 to BI89 is substantially equal to the red target beam intensity TBIR.
The current values I80 to I89 flowing through the current 89 are obtained and set.

Similarly, the beam intensity of each of the measured infrared laser beams is changed and adjusted by changing the value of the current flowing through the laser diode in accordance with the ratio between BI70 to BI79 and the infrared target beam intensity TBIIR. The laser beams are emitted again from the plurality of laser diodes LD70 to LD79, and the plurality of laser diodes LD70 are
The measurement of the beam intensities BI70 to BI79 of the respective laser beams emitted from the LD79 is repeated so that the beam intensities BI70 to BI79 of the respective laser beams are substantially equal to the infrared target beam intensity TBIIR. Current value I70 to be supplied to LD70 to LD79
Obtain and set I79.

Further, the laser diode control section 4 has a plurality of types of plate making photographic films capable of recording latent images in advance by the image recording apparatus of the present embodiment. The quantity KRPI is preset. Then, the laser diode control unit 4 reads out the film type exposure intensity adjustment amount KRPI according to the type of photographic paper on which the latent image is recorded. Then, the laser diode controller 4 adds the exposure intensity adjustment amount correction amount ΔRPI and the film type exposure intensity adjustment amount KRPI to add the exposure intensity adjustment amount RPI.
Ask for.

RPI = KRPI + ΔRPI Then, the laser diode control unit 4 transmits the obtained exposure intensity adjustment amount RPI to the exposure intensity adjustment unit 5 as binary numerical data. Then, the exposure intensity adjustment unit 5 determines the optical wedge filter 5 according to the transmitted exposure intensity adjustment amount RPI.
8 is controlled to be inserted into the optical path of the laser beam.

Further, the entire laser beam is converged to a substantially single point by the converging lens group 38, and the optical wedge filter 58 is located at this convergent point, so that the degree of freedom of the positional relationship between the laser beam and the optical wedge filter 58 is reduced. Increase,
The beam intensities of all the laser beams can be shifted exactly by the same amount without being affected by the unevenness of the optical wedge filter 58.

[0086]

According to the first and second aspects of the present invention, a laser beam emitted from a plurality of laser diodes, for example, when the tone reproduction of an output image that needs to be frequently performed is changed or when a recording material is changed. Shifting of all exposure intensities can be easily and stably performed in a short time.

According to the third aspect of the invention, it is possible to satisfactorily correct not only the fluctuation of the light emission intensity of the laser diode with the passage of time but also the fluctuation of the beam intensity of each laser beam including the fluctuation of the beam intensity due to a change in the optical axis.

According to the fourth aspect, even if the mounting positions of the laser diodes of the plurality of laser diodes are not high enough to shift the recording positions of the respective laser beams on the recording material in the main scanning direction, the light due to the environment, aging, etc. The effect of the deviation of the recording position of the laser beam emitted from each laser diode in the main scanning direction due to axis deviation or the like can be satisfactorily corrected, and good recording can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an image recording apparatus according to a first embodiment.

FIG. 2 is a block diagram of the image recording apparatus according to the first embodiment.

FIG. 3 is a diagram of a recording surface RS viewed from the front.

FIG. 4 is a schematic diagram of the vicinity of an exposure intensity adjusting unit 5 according to the first embodiment.

FIG. 5 is a view of a recording surface RS of another example as viewed from the front.

FIG. 6 shows an exposure intensity adjusting unit 5 of the image recording apparatus according to the second embodiment.
FIG.

FIG. 7 is a diagram of the disk-type optical wedge filter 60 of the image recording apparatus according to the third embodiment as viewed from the converging lens group 24 side.

FIG. 8 shows an exposure intensity adjusting unit 5 of the image recording apparatus according to the third embodiment.
FIG.

FIG. 9 is a schematic configuration diagram of an image recording apparatus according to a fifth embodiment.

[Explanation of symbols]

 CP center point CS adjustment surface MSD sub-scanning direction RS recording surface SSD main scanning direction 1 optical unit 2 drum 3 light receiving element 4 laser diode control unit 5 exposure intensity adjustment unit 6 emission timing control unit 10 light source unit 20 beam alignment optical system 21 lens 22, 23 mirror 24 converging lens group 25 reduction optical lens group 26 cylindrical lens 51 to 55 filter 58 optical wedge filter 60 disk type optical wedge filter 70 infrared light source section 80 red light source section 90 green light source section

Claims (11)

[Claims] 1. A light source unit in which a plurality of laser diodes are aligned, a beam alignment optical system for aligning laser beams emitted from the plurality of laser diodes on a recording surface of a recording material in a sub-scanning direction, and the plurality of lasers Moving means for relatively moving the laser beam emitted from the diode and the recording material in the main scanning direction, measuring means for measuring the beam intensity of each laser beam emitted from the plurality of laser diodes, and the measuring means Laser diode control means for controlling each laser diode of the plurality of laser diodes so that the beam intensity of each laser beam becomes equal according to the measured beam intensity of each laser beam. The filter controls the exposure intensity of all the laser beams emitted from the plurality of laser diodes. An image recording apparatus comprising a filter adjusting means for shifting a degree. 2. The apparatus according to claim 1, wherein said filter adjusting means selectively inserts and removes a plurality of filters having different densities into and from the optical path of the laser beam, thereby shifting the exposure intensity of all laser beams emitted from said plurality of laser diodes. The image recording apparatus according to claim 1, wherein 3. The apparatus according to claim 1, wherein said filter adjusting means has an optical wedge filter, and shifts an exposure position of all the laser beams emitted from said plurality of laser diodes by changing a beam incident position on said optical wedge filter. The image recording apparatus according to claim 1, wherein 4. The plurality of laser diodes so that the optical wedge filter is a disk-type optical wedge filter and a beam incident position on the disk-type optical wedge filter is in the same radial direction of the disk-type optical wedge filter. 4. The image recording apparatus according to claim 3, wherein the laser beam emitted from the optical disc is made incident on the optical wedge filter. 5. The image recording apparatus according to claim 1, further comprising a beam converging unit that converges incident positions of all laser beams emitted from the plurality of laser diodes on the filter to substantially one point. 6. A light source unit in which a plurality of laser diodes are aligned, a beam alignment optical system for aligning laser beams emitted from the plurality of laser diodes on a recording surface of a recording material in a sub-scanning direction, and the plurality of lasers Moving means for relatively moving the laser beam emitted from the diode and the recording material in the main scanning direction, measuring means for measuring the beam intensity of each laser beam emitted from the plurality of laser diodes, and the measuring means Laser diode control means for controlling each laser diode of the plurality of laser diodes so that the beam intensity of each laser beam becomes equal according to the measured beam intensity of each laser beam. And the exposure intensity of all the laser beams emitted from the plurality of laser diodes by the polarizer. An image recording apparatus, comprising: a polarizer adjusting means for shifting the wavelength. 7. The image recording apparatus according to claim 6, further comprising beam converging means for converging incident positions of all laser beams emitted from the plurality of laser diodes on the polarizer to substantially one point. 8. A light source unit in which a plurality of laser diodes are aligned, a beam alignment optical system for aligning laser beams emitted from the plurality of laser diodes on a recording surface of a recording material in a sub-scanning direction, and the plurality of lasers. Moving means for relatively moving the laser beam emitted from the diode and the recording material in the main scanning direction, measuring means for measuring the beam intensity of each laser beam emitted from the plurality of laser diodes, and the measuring means A laser diode control unit that controls each of the plurality of laser diodes according to the measured beam intensity of each laser beam, wherein the measurement unit includes the beam alignment optical system. The plurality of lasers are moved by a light-receiving element that can move relatively to a position where the laser beam emitted from the An image recording apparatus for receiving each laser beam emitted from the beam alignment optical system emitted from the laser diode and measuring the beam intensity of each laser beam emitted from the plurality of laser diodes. 9. The image recording apparatus according to claim 8, wherein the light receiving element is movable relative to a recording surface of the recording material by the laser beam. 10. A light source unit in which a plurality of laser diodes are aligned, a beam alignment optical system for aligning laser beams emitted from the plurality of laser diodes on a recording surface of a recording material in a sub-scanning direction, and the plurality of lasers. A moving means for relatively moving the laser beam emitted from the diode and the recording material in the main scanning direction, wherein each laser diode of the plurality of laser diodes is individually An image recording apparatus comprising light emission timing control means for delaying light emission timing of a diode. 11. A recording position detector which detects a recording position of each laser beam emitted from the plurality of laser diodes, the recording position detector being movable relative to a recording surface of the recording material by the laser beam, The light emission timing control means individually controls the light emission timing of each laser diode of each of the plurality of laser diodes according to the recording position of the laser beam emitted from each laser diode detected by the recording position detector. The image recording apparatus according to claim 10, wherein the image recording apparatus delays the image recording.