JPH02220018A - Light beam controller, light beam scanner, and light beam multiplexer - Google Patents

Abstract

PURPOSE:To utilize the whole light beam emitted by a light source effectively and to control the position and diameter of the light spot speedily by irradiating an irradiated object with a beam of 0th order and a beam of 1st order which irradiates by an acoustooptic element (AO element) closely to each other and forming their composite spot. CONSTITUTION:The laser beam 2 which is emitted by the laser light source 1 is made incident on the AO element 3 and split into the beam 2a of 0th order and the beam 2b of 1st order, which are emitted in mutually different directions. The beam 2a of 0th order and the beam 2b of 1st order which are emitted by the AO element 3 after passing through a lens 6 are reflected and deflected by a rotary polygon mirror 8 which is rotated fast by a motor 7 as shown by an arrow A to irradiate a scanned body 4 through an ftheta lens 9 and a reflecting mirror 10. The scanning optical system is so constituted that the segment connecting the two light spots 11a and 11b formed by the beams 2a and 2b crosses the scanning line 5 at right angles. The two light spots 11a and 11b operate as one composite spot of them.

Description

[Detailed description of the invention] (Industrial application field).

The third aspect of the present invention is a light beam control device for controlling the spot diameter and the irradiation position when a light beam is irradiated onto an irradiated object, which is used in, for example, an image reading device or a laser printer. Related to a light beam scanning device that scans a scanning body, and a light beam multiplexing device that combines light beams emitted from multiple light sources when the intensity of the light beam emitted from one light source is weak. It is.

(Prior art) A recording sheet on which an image is recorded is scanned with a light beam to obtain an image signal, this image signal is subjected to image processing, and the light beam is modulated based on the image signal subjected to image processing. Systems are used in various fields, such as scanning a recording sheet using a digital camera, and reproducing and recording an image on the recording sheet.

For example, recording an X-ray image using a low gamma X-ray film designed to be compatible with subsequent image processing;
The X-ray image is read from the film on which it is recorded, converted into an electrical signal, and after image processing is applied to this electrical signal (image signal), the contrast is reproduced as a visible image in a copy photograph, etc. A system has been developed that can obtain reproduced images with good image quality performance such as sharpness, graininess, etc. (see Japanese Patent Publication No. 5193/1983).

In addition, the applicant has proposed radiation (X-rays, β-rays).

When irradiated with β-rays, γ-rays, 1Ts consonant rays, ultraviolet rays, etc., a part of this radiation energy is accumulated, and then when excitation light such as visible light is irradiated, stimulable fluorescence exhibits stimulated luminescence depending on the accumulated energy. A radiation image of a subject such as a human body is photographed and recorded on a sheet of stimulable phosphor using a stimulable phosphor, and this stimulable phosphor sheet is scanned with excitation light such as a laser beam. The resulting stimulated luminescent light is read photoelectrically to obtain an image signal, and based on this image signal, a radiation image of the subject can be recorded on recording materials such as photographic materials, CRTs, etc. A radiation image recording and reproducing system that outputs visual images has already been proposed (Japanese Unexamined Patent Publication No. 5
No. 5-12429, No. 5B-11395.

55-1 [No. 13472, No. 58-104845,
No. 55-116340, etc.).

This system has the practical advantage of being able to record images over a much wider range of radiation exposure compared to conventional radiographic systems using silver halide photography. In other words, in a stimulable phosphor, it is recognized that the amount of emitted light that is stimulated to emit light due to excitation after accumulation is proportional to the amount of radiation exposure over an extremely wide range.
Therefore, even if the amount of radiation exposure varies considerably due to various imaging conditions, the amount of stimulated luminescence emitted from the stimulable phosphor sheet can be read by the photoelectric conversion means by setting the reading gain to an appropriate value. By converting the radiation image into an electric signal and using this electric signal to output the radiation image as a visible image to a recording material such as a photographic light-sensitive material or a display device such as a CRT, a radiation image that is not affected by fluctuations in radiation exposure amount can be obtained. be able to.

In the above-mentioned systems that use X-ray film, stimulable phosphor sheets, etc., and various systems that handle general images, etc., in order to read images and obtain image signals, it is necessary to use A light beam is scanned over a stimulable phosphor sheet or other recording sheet, and the light (for example, X
An image reading device is used that obtains an image signal by receiving light transmitted through an X-ray film or reflected from an X-ray film, stimulated luminescence light emitted from a stimulable phosphor sheet, etc., with a photodetector. In order to obtain a visible image based on an image signal, an image recording apparatus is used that scans a recording sheet such as a photosensitive film for image recording with a light beam whose intensity is modulated based on the image signal.

In addition, in these image reading devices, image recording devices, etc.
When the light intensity of the light beam emitted from one light source is weak, a plurality of light sources are provided and the plurality of light beams emitted from the plurality of light sources are combined to form the same spot on the recording sheet. Sometimes things are done.

(Problem to be Solved by the Invention) In the image reading device, image recording device, etc. mentioned above, it is necessary to strictly control the spot diameter of the light spot formed by irradiating the light beam onto the recording sheet and the irradiation position. There is. Furthermore, when performing the above-mentioned multiplexing, it is necessary to perform delicate positioning of each optical spot corresponding to each optical beam. For example, in the above-mentioned image reading device, when the spot diameter of the light spot increases, the spatial frequency characteristics of the image information carried by the obtained image signal deteriorate, resulting in a decrease in sharpness, and in the above-mentioned image recording device, When the spot position changes for each scanning line, density unevenness occurs in a direction perpendicular to each scanning line, resulting in a decrease in image quality.

Until now, to control the spot diameter and spot position of the light spot, for example, a beam expander was used.

This has been accomplished by providing optical members such as reflective mirrors on the optical path and driving these optical members with mechanical actuators such as motors and piezo elements. With this method of driving optical members using mechanical actuators, it is difficult to obtain high responsiveness, and since it is a mechanical control method, durability is poor, and furthermore, the number of parts increases, resulting in higher costs. was there. Therefore, it is difficult, for example, to control the spot position at high speed during continuous scanning of one or more recording sheets due to responsiveness problems.

Additionally, in order to control the spot position for each scanning line during continuous scanning of - recording sheets, it is considered that an acousto-optic optical deflector (AOD) is provided on the optical path. (For example, a patent application filed by the present applicant in which an AOD is used for the purpose of multiplexing multiple light beams;
(See Japanese Patent Application No. 80-58941, Japanese Patent Application No. 80-121655). An AOD separates an incident light beam into a zero-order beam and a first-order beam and emits them in different directions, and changing the frequency of the ultrasonic waves that drive the AOD changes the direction of the first-order beam. It has characteristics. Therefore, by using the primary beam emitted from this AOD, the spot position can be controlled.

However, the light intensity of the primary beam emitted from the AOD is at most 70% of the light intensity of the light beam incident on the AOD.
~80%, and 20~30% remain as the 0th order beam.
% is wasted, and the problem is that it is necessary, for example, to install an expensive light source with a large optical output, or to increase the number of light beams to be combined and adopt a correspondingly more complex optical system. there were.

In view of the above problems, the present invention provides a light beam control device that can effectively utilize the entire light beam emitted from a light source and control the position and diameter of a light spot at high speed, and the light beam control device. A light beam scanning device that eliminates scanning unevenness by controlling the scanning position shift of a mechanical optical deflector such as a rotating polygon mirror or a galvanometer mirror, and a light beam control device described above to correct the shift in multiplexing. The object of the present invention is to provide an optical beam multiplexing device that achieves this.

(Means for Solving the Problems) The light beam control device of the present invention comprises: a light source such as a laser light source that emits a light beam; an acousto-optic element that separates the light beam into a zero-order beam and a first-order beam; an irradiation optical system that irradiates a zero-order beam and the first-order beam onto a position close to each other on an irradiated object to form a composite spot in which two light spots of the zero-order beam and the first-order beam are combined; It is characterized by comprising a control circuit that controls the position and/or size of the composite spot by driving the acousto-optic element and controlling the intensity ratio and/or interval between the two light spots. be.

Here, the above-mentioned "acousto-optic device" (hereinafter referred to as "AO device") is a general term for a device that separates an incident light beam into a zero-order beam and a first-order beam through the interaction between an ultrasonic wave and a light beam. and when the "control circuit" changes the intensity of the ultrasonic wave, an acousto-optic light modulator in which the light intensity of the zero-order beam and the first-order beam is modulated according to the intensity of the ultrasonic wave. (AOM) is configured, and if the "control circuit" changes the frequency of the ultrasonic wave, the above-mentioned AOD is configured. Furthermore, the "control circuit" may be one that changes both the intensity and frequency of the ultrasonic waves.

Further, the light beam scanning device of the present invention includes a light source that emits a light beam, a zero-order beam and a first order light beam.
An AO element that separates the 0th-order beam and the 1st-order beam onto a position close to each other on the object to be scanned, and
A mechanical optical deflector such as a rotating polygon mirror or a galvanometer mirror is provided, which forms a composite spot by combining two light spots of the secondary beam and the primary beam, and scans the object to be scanned with the composite spot. a scanning optical system, and a control circuit that drives the AO element and controls the intensity ratio of the two light spots so as to correct positional fluctuations of the scanning line during the scanning by the mechanical optical deflector. It is characterized by this.

Further, the light beam multiplexing device of the present invention includes: a plurality of light sources that emit light beams, each of the plurality of light sources, or the plurality of light sources provided corresponding to each light source except one light source among the plurality of light sources; An AO element that separates a light beam into a 0-order beam and a 1st-order beam, and the 0-order beam and the 1st-order beam emitted from each AO element are irradiated onto a position close to each other on the irradiated object to form the 0-order beam. a combining optical system that forms a combined spot by combining the beam and two light spots of the primary beam, and combines the plurality of light beams emitted from the plurality of light sources onto the irradiated object; It is characterized by comprising a control circuit that drives the AO element and controls the intensity ratio and/or interval between the two light spots so as to correct a shift in the combination of the plurality of light beams. be.

(Function) The light beam control device of the present invention irradiates a zero-order beam and a first-order beam irradiated from an AO element onto a position close to each other on an irradiated object. 2
Since the two light spots are combined to form a composite spot, the light intensity used as this composite spot is approximately 1, which is the sum of the 0th-order beam and the 1st-order beam.
00% light intensity. Also, by driving the AO element, the A
2 due to the 0th-order beam and the 1st-order beam emitted from the O element
Since the control circuit is provided to control the intensity ratio and/or interval of the two light spots, the position of the composite spot where these two light spots are combined.

The size can be adjusted. Further, this adjustment can be carried out instantaneously without the need to stop the apparatus.

Further, the light beam scanning device of the present invention includes a scanning optical system equipped with a mechanical light deflector that scans the object to be scanned using the composite spot, and drives an AO element to deflect the mechanical light. Since it is equipped with a control circuit that controls the intensity ratio of the two light spots mentioned above so as to correct the positional fluctuation of the scanning line during scanning by the device, it is possible to correct the positional fluctuation of the scanning line due to, for example, the tilting of the surface of the rotating polygon mirror. Therefore, when this light beam scanning device is used in the above-mentioned image reading device, it is possible to accurately read an image, and when used in an image recording device, it is possible to always move the light spot on the same scanning line. In addition, it is possible to reproduce a visible image with excellent image quality without uneven density or the like.

Furthermore, the light beam multiplexing device of the present invention applies the above-mentioned light beam control device to the position adjustment of the light beams from each light source that are multiplexed onto the object to be irradiated by the multiplexing optical system. The light beam multiplexing device of the present invention includes a combining optical system that forms a composite spot on an irradiated object and multiplexes a plurality of light beams emitted from a plurality of light sources onto the irradiated object. , control for driving the AO element to control the intensity ratio and/or interval of two light spots formed by the 0th-order beam and the 1st-order beam so as to correct the shift in the combination on the irradiated object. Because it is equipped with a circuit, it is possible to make fine adjustments that cannot be made by mechanical adjustment of the white wave optical system, and it also prevents fluctuations in the multiplexing due to heat in the multiplexing optical system and fluctuations in the multiplexing over time. It is also possible to take immediate action without stopping the equipment.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing a schematic configuration of an embodiment of a light beam scanning device of the present invention using a light beam control device of the present invention.

A laser beam 2 emitted from a laser light source 1 enters an AO element 3 and is separated into a zero-order beam 2a and a first-order beam 2b, which are emitted in different directions. The AO element 3 is arranged at a position slightly shifted from the waist of the laser beam 2, so that the zero-order beam and the first-order beam form optical spots on the object to be scanned 4 at positions close to each other. A
Zero-order beam 2a and first-order beam 2 emitted from O element 3
After b passes through a lens 6, it is reflected and deflected by a rotating polygon mirror 8 which is rotated at high speed in the direction of arrow A by a motor 7, and f
The light is irradiated onto the object to be scanned 4 via the θ lens 92 and the reflecting mirror 10. Each beam 2a, 2 on the object to be scanned 4
Light spots 11a and fl respectively formed by
b, the scanning optical system is configured such that the line segment connecting these two light spots 11a and 11b is perpendicular to the scanning line 5. Two light spots 11a! lb acts as a single light spot (hereinafter referred to as a composite spot) where these are combined. The object to be scanned 4 is scanned by a scanning line 5 due to the rotation of the rotating polygon mirror 8 due to this composite spot.
is repeatedly scanned in the direction of arrow B.

Incidentally, the mirror surfaces of the rotating polygon mirror may be tilted to each other (surface tilt) due to manufacturing errors. For example, the scanning line 5a,
5b etc., the position of the scanning line fluctuates with one rotation of the rotating polygon mirror 8 as one cycle.

If there is such a periodic variation in the scanning line, when this light beam scanning device is used in an image reading device, an image signal with periodic unevenness in a direction perpendicular to the scanning line will be obtained. Furthermore, when this light beam device is used in an image recording device, density unevenness similarly occurs in a visible image obtained based on an even image signal.

Therefore, in this light beam scanning device, the tilt of the rotating polygon mirror is corrected as follows.

P to detect the position of the light irradiated near the start point of scanning
S D (position 5enslt1ve d
evice) f2 is arranged to monitor the position of the composite spot passing over this PSDI 2 in the direction orthogonal to the scanning line, and this monitoring result drives the AO element 3 to control the position of the composite spot. It is input to the circuit 13. The control circuit 13 changes the intensity ratio of the zero-order beam 2a and the first-order beam 2b so that the composite spot always scans the same scanning line 5.

FIG. 2 is a diagram showing the intensity distribution of two light spots 11a and 11b by the zero-order beam and the first-order beam, and the intensity distribution of the composite spot 11 where they are combined. The horizontal axis indicates the direction perpendicular to the scanning line 5 at the position where the scanned object 4 is irradiated with the composite spot shown in FIG. (a
) are two light beams lla, l with light intensities of -
181 is a diagram showing the intensity distribution of the composite beam ll when irradiated onto the scanned object 4 shown in FIG. 181 at a predetermined interval.

In (b), the intensity of the 0th-order beam is thicker due to the AO element 3,
FIG. 7 is a diagram showing the intensity distribution of the composite beam ti when the intensity of the primary beam is controlled to be small. (C) is
7B is a diagram showing the intensity distribution of the composite beam 11 when the AO element 3 controls the intensity of the 0th-order beam to be small and the intensity of the 1st-order beam to be large, contrary to the case of FIG. In (b) and (c), two light spots 1
The spacing between 1a and llb is the same as in case (a).

When the AO element 3 is controlled as shown in (b) and (c),
The center of the composite spot 11 moves to the left and right in the figure, so by performing this control based on the results of monitoring the scanning position by the PSD 12 shown in FIG. scanned along.

In each of the above embodiments, when the center position of the composite spot 11 is controlled, the spot diameter also changes accordingly. The effect of this change in spot diameter is the rotating polygon 11!
This varies depending on the size of the surface tilt of the light beam scanning device 8 and the use of the light beam scanning device, but normally this does not cause any major problems.

In the embodiment shown in FIG. 1, the AO element 3 is used as an AOM to change the intensity ratio of the 0th-order beam and the 1st-order beam, thereby controlling to change the position of the combined spot.
Although the case where surface tilt correction is performed has been described, if the control circuit 13 is changed to function as an AOD instead of an AOM, the size of the composite spot 11 can also be controlled by changing the emission direction of the primary beam 2b. can.

(d) and (+3) in Fig. 2 are the 1 beams emitted from the AO element without changing the intensity ratio of the 0th-order beam 2a and the 1st-order beam 2b.
Control is performed to change the irradiation position of the primary beam 2b on the object to be scanned 4, that is, the interval between the two light spots 11a and 11b, by changing the emission direction of the secondary beam. As shown in (a), (d), and (e), by changing the irradiation position of the primary beam using the AO element, the center position of the composite spot also changes.

Alternatively, a control circuit may be configured that allows the AO element to have both AOM and AOD functions, and both the intensity ratio of the 0th-order beam and the 1st-order beam and the emission direction of the 1st-order beam may be changed at the same time. Of course.

Although the above embodiment is an example in which the light beam control device of the present invention is applied to a light beam scanning device, the light beam control device of the present invention does not necessarily have to include a scanning optical system, and the diameter or position of the light spot is Wide (applicable) when adjusting $111iIl or.

FIG. 3 is a perspective view showing an outline of an embodiment of the optical beam multiplexing device of the present invention using the optical beam control device of the present invention.

The laser beam 22 emitted from the laser light source 21 is linearly polarized, and the laser beam 22 is linearly polarized. AO element 24. lens 25
via a polarizing beam splitter (hereinafter referred to as J'B
Call it S. >28 is transmitted. In this way, the rotational position of the laser light source 21 with respect to the optical path of the laser beam 22 is determined so that the laser beam 22 passes through the PBS 2 (l).

The laser beam 28 emitted from the other laser beam [27 is reflected by a mirror 29, and then passes through a lens 80° AO
Element 31. Via lens 32, P B 826
reflected by. In this way, the laser beam 28 is
The rotational position of the laser beam 'R27 with respect to the optical path of the laser beam 28 is determined so that it is reflected by the BS28.

The laser beam 22 (both the 0th order beam and the 1st order beam) that has passed through the PB52B and the laser beam 28 (both the 0th order beam and the 1st order beam) that has been reflected by the PBS2[i] are on the optical path 33 between the paths. The waves are combined so that they overlap. Most of the light intensity of the two combined laser beams 22, 28 is reflected by the half mirror 34, reflected and deflected by the rotating polygon mirror rotating at high speed in the direction of arrow C, and then reflected and deflected by the fθ lens 38. The object to be scanned 38 is repeatedly scanned in the direction of the arrow along the scanning line 39 via the reflection mirror 37 . still,
Here, the surface tilt of each mirror surface of the rotating polygon mirror 35 is so small that it does not require correction, or is corrected by a surface tilt correction optical system (not shown) using a method different from that used in the light beam scanning device of the present invention. It is assumed that

Further, the laser beams 22 and 28 are connected to the AO elements 24 and 24, respectively.
．． 31, because the beam is divided into the ΩwK+ beam and the primary beam, the optical paths of each beam (strictly speaking, are not the same optical path).Secondly, finally on the scanned object 38, the AO @ The 0th order beam and 1st order beam emitted from j! The above-mentioned optical system is configured so that positions close to each other are irradiated to form a composite spot, and further, these two composite spora) almost overlap to form one spot. Here, the two AO elements 24 and 31 are arranged so that they are optically perpendicular to each other, that is, the line segment connecting the centers of the two light spots of the zero-order beam and the first-order beam emitted from the AO element 24 is the scanning point 11.
The scanning line 39 is arranged so that a line segment connecting the centers of two light spots formed by the zero-order beam and the first-order beam emitted from the AO element 31 is perpendicular to the scanning line 39 .

The laser beam 22.28 transmitted through the half mirror 34 passes through the lens 40, and after its optical path is divided by the PBS 41, it passes through two laser beams arranged at a position optically conjugate with the scanning line 39 of the scanned object 38. Monitored by PSD42.43. The PSD 42 is a scanning line 39 direction of a light spot that is multiplexed and formed on the object to be scanned.
3 detects the deviation of the light spot in the direction orthogonal to the scanning line 39, and sends the signal to control circuits 44 and 45 that respectively control the AO elements 24 and 31. The control circuits 44 and 45 respectively drive the AO elements 24 and 31 to adjust the 0th-order beam and the 1st-order beam so as to correct the misalignment in the direction of the scanning line 39 and in the direction orthogonal to the scanning line 39, respectively. Control intensity ratio. In the above embodiment, the control circuit 44.45 controls the intensity ratio of the zero-order beam and the first-order beam emitted from the AO element 24.31. Of course, the direction in which the light is emitted may be changed.

Further, although two AO elements 24 and 31 are used in the above embodiment, for example, one AO element may be used for the purpose of correcting a combining shift in one direction such as the main scanning direction. Further, in the above embodiment, two laser beams 22.2B are combined, but the present invention can also be applied to multiplexing of three or more laser beams.

FIG. 944 is a perspective view of a radiation image reading device including an example of the light beam control device of the present invention.

This radiation image reading device uses the above-mentioned stimulable phosphor sheet.

A stimulable phosphor sheet 51 on which a radiation image is recorded is set at a predetermined position of the radiation image reading device 100. The stimulable phosphor sheet 51 set in this predetermined position is
A sheet conveying means 53 such as an endless belt driven by a motor 52 conveys (sub-scans) in the direction of arrow Y. On the other hand, a laser beam 55 emitted from a radar light source 54 passes through an AO element 5B and a lens 57, is reflected and deflected by a galvanometer mirror 59 that swings at high speed in the direction of arrow E, and passes through a focusing lens 60 such as an fθ lens. After that, the optical path is changed by the mirror 61 and the above-mentioned sea) 5
1 and performs main scanning repeatedly in the direction of arrow X, which is substantially perpendicular to the direction of sub-scanning (direction of arrow Y). Here, two beams are formed on the sheet 51 by the zero-order beam and the first-order beam separated by the AOD 58.
The optical system is configured such that the two light spots are formed at positions close to each other that are lined up in the main scanning direction (X direction). A stimulated luminescent light 82 is emitted from a portion of the sheet 51 that is irradiated with this excitation light (laser beam) 55, and the amount of stimulated luminescent light 82 corresponds to the radiation image information that has been stored and recorded, and this stimulated luminescent light B2 is It is guided by a guide 63 and photoelectrically detected by a photomultiplier (photomultiplier tube) 64.

The light guide 63 is made by molding a light-guiding material such as an acrylic plate, and is arranged so that a linear incident end surface 83a extends along the main scanning line on the stimulable phosphor sheet 51. The light receiving surface of the photomultiplier 64 is coupled to the annularly formed exit end surface 81b. Stimulated luminescent light 6 entering the light guide 63 from the incident end surface B3a
2 travels through the interior of the light guide 63 through repeated total reflection, exits from the exit end surface B3b, and enters the photomultiplier B.
The photomultiplier 64 converts the amount of stimulated luminescence light B2, which is received by the photomultiplier 4 and represents a radiation image, into an electrical signal S.

The electrical signal S representing this radiation image is sent to a logarithmic amplifier 65
The signal is logarithmically amplified by the A/D converter BB and digitized by the A/D converter BB to obtain the image signal SQ. Obtained image signal SQ
is once stored in the storage means 67, and then the image processing device 20
Sent to G.

The image processing device 200 performs appropriate image processing on the received image signal S0.

The image signal SQ subjected to image processing is sent to the image reproduction device 300.
This image signal So is transmitted to the image reproduction device 300.
! :Based (radiation images are played back and recorded.

In the radiation image reading device configured as described above,
The speed of main scanning (speed of rocking of galvanometer mirror 59) is controlled by galvanometer control circuit 88, and the speed of sub-scanning (speed of motor 52) is controlled by motor control circuit 89. A signal related to the swing speed (main scanning speed) of the galvanometer mirror 59 is output from the galvanometer control circuit 88 and input to the control circuit 70 that controls the AO element 58 .

The control circuit 70 changes the spot diameter in the main scanning direction of the light spot irradiated and formed on the sheet 51 by changing the emission direction of the primary beam emitted from the AO element 56 according to the main scanning speed. By changing the value to be larger as the speed is faster, it is possible to obtain an image signal So carrying image information with appropriate sharpness regardless of the main scanning speed.

In the above embodiment, the spot diameter in the main scanning direction is changed, but the spot diameter in the sub-scanning direction can be changed by arranging the optical system so that the two light spots of the zero-order beam and the first-order beam are lined up in the Y direction. It may be controlled, and the two light spots may be
The spot diameter in both the X and Y directions may be controlled simultaneously by arranging the optical system so that the spot diameter is in an oblique direction different from both the X and Y directions.

(Effects of the Invention) As described above in detail, the present invention irradiates a zero-order beam and a first-order beam emitted from an AO element onto a position close to each other on an irradiated object, and The two light spots from the second beam form a composite spot, and the position or size of the composite spot is controlled by controlling the intensity ratio or interval of these two light spots, so the light beam emitted from the light source The entire area can be used effectively and the position and diameter of the light spot can be adjusted instantaneously. It can also be applied to correct scanning line position fluctuations in optical beam scanning devices equipped with mechanical optical deflectors to eliminate scanning unevenness, and can also be used to combine optical beams emitted from multiple light sources. It can also be applied to correcting deviations.

[Brief Description of the Drawings] Fig. 1 is a schematic configuration diagram of an embodiment of a light beam scanning device of the present invention using a light beam control device of the present invention, and Fig. 2 shows a zero-order beam and a first-order beam. The third fl is a diagram showing the intensity distribution of two light spots caused by a beam and the intensity distribution of a composite spot where these are combined, and FIG. FIG. 4 is a perspective view showing an overview of an embodiment of the invention. FIG. 1 is a perspective view of the I image reading device. 1, 21.27.54...Laser light source 2, 22.28
．． 55... Laser beam 3.24.81.5t.AO
Element 4.38... Scanned object 8, 85... Rotating polygon mirror 12, 42.43... PSD (semiconductor device sensor)
13, 44. 45. 70... Control circuit 51... Stimulable phosphor sheet 59... Galvanometer mirror Fig.

Claims (3)

[Claims] (1) A light source that emits a light beam, an acousto-optic element that separates the light beam into a zero-order beam and a first-order beam, and an acousto-optic element that irradiates the zero-order beam and the first-order beam onto positions close to each other on the irradiated object. an irradiation optical system that forms a composite spot in which two light spots of the zero-order beam and the first-order beam are combined;
and a control circuit that controls the position and/or size of the composite spot by driving the acousto-optic element and controlling the intensity ratio and/or interval of the two light spots. Beam control device. (2) A light source that emits a light beam, an acousto-optic element that separates the light beam into a zero-order beam and a first-order beam, and an acousto-optic element that irradiates the zero-order beam and the first-order beam onto positions close to each other on the object to be scanned. a scanning optical system equipped with a mechanical optical deflector, which forms a composite spot in which two light spots of the zero-order beam and the first-order beam are combined, and scans the object to be scanned with the composite spot; and a control circuit that drives the acousto-optic element and controls the intensity ratio of the two light spots so as to correct positional fluctuations of the scanning line during the scanning by the mechanical optical deflector. A light beam scanning device. (3) A plurality of light sources that emit light beams, which are provided corresponding to each of the plurality of light sources or each light source excluding one light source among the plurality of light sources, and the light beams are divided into zero-order beams and first-order beams. an acousto-optic element that separates into beams; the zero-order beam and the first-order beam emitted from each acousto-optic element are irradiated onto a position close to each other on the irradiated object, and the zero-order beam and the first-order beam A combining optical system that forms a composite spot in which two light spots are combined and combines a plurality of light beams emitted from the plurality of light sources onto the irradiated object, and drives the acousto-optic element. A light beam multiplexing device comprising: a control circuit that controls the intensity ratio and/or the interval between the two light spots so as to correct a shift in the multiplexing of the plurality of light beams.