JP2826222B2 - Assembling method of semiconductor laser - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image exposure apparatus that uses a semiconductor laser as a light beam source and exposes the object to be scanned by raster scanning or the like. precisely incident on a predetermined position of the upper
On how to assemble semiconductor lasers
You.

[0002]

2. Description of the Related Art An image exposing apparatus using a so-called raster scan, which exposes an object to be scanned relatively moving in a sub-scanning direction substantially orthogonal to the main scanning direction with a light beam deflected in the main scanning direction, uses an image exposure apparatus. It is applied to a recording device, a printing plate making device, and the like. In addition, as a light source of a light beam of an image exposure apparatus using a raster scan, a semiconductor laser (hereinafter, referred to as an LD) is inexpensive and compact.
Is often used.

[0003] Such an image exposure apparatus is, for example, a color image exposure apparatus to which three LDs corresponding to three colors of cyan (C), magenta (M) and yellow (Y) are applied. First, the light beam emitted from the LD is shaped into parallel light by collimator lenses arranged correspondingly. Each light beam shaped by the collimator lens is then incident on an optical deflector such as a polygon mirror and is one-dimensionally deflected in the main scanning direction.
The light is adjusted by a lens so as to form an image at a predetermined position with a predetermined beam diameter, and is incident on a predetermined position of a scanned object such as a recording material.

The object to be scanned is relatively moving in a sub-scanning direction substantially orthogonal to the main scanning direction. Therefore, the light beam deflected in the main scanning direction consequently scans the object to be scanned two-dimensionally, whereby the entire surface of the object to be scanned can be image-exposed by the light beam.

In an image exposure apparatus to which raster scanning is applied, in order to perform high-quality image exposure, it is necessary to accurately irradiate a predetermined position on a scanned object with a light beam having a predetermined beam diameter. . If the beam diameter of the light beam or the irradiation position on the object to be scanned is out of order, inconsistencies in the image forming position, image blurring, etc. occur, and a high-quality image cannot be obtained. In particular, in an image exposure apparatus that forms a color image as described above,
If the relationship between the incident positions of the light beams corresponding to the exposures of C, M, and Y is out of order, a so-called color shift occurs, and a satisfactory color image cannot be formed.

Various factors such as an error in the accuracy of the optical member and a deviation in the arrangement position can be considered as a cause of the deviation of the beam diameter or the irradiation position on the scanned object. One of the major causes is the LD. And a collimator lens.

[0007]

As described above, in an image exposure apparatus using an LD as a light source, a collimator lens is arranged to shape a light beam emitted from the LD into parallel light. , LD and a collimator lens are combined and arranged as a light source unit. FIG. 3 shows a schematic sectional view of such a light source unit.

In the light source unit 100 shown in FIG. 3, an LD 102 as a light source is inserted so as to be dropped into a holding hole 106 formed on a heat radiating plate 104 and having the same shape as the LD 102, and is pressed from the rear side by a leaf spring 108. It is held by being. That is, the heat sink 1
Reference numeral 04 also functions as a holding member for the LD 102 in addition to the function as the heat radiation member. On the other hand, the collimator lens 110 is fixed at a predetermined position in a cylindrical lens barrel 112.

A screw 114 is formed in the lens barrel 112, and a screw groove 116 in which the screw 114 is screwed is formed in the heat radiating plate 104, and the heat radiating plate 104 and the lens barrel 112 are screwed together. Are integrated to form the light source unit 100. In addition, such a light source unit 1
In the case of 00, the optical axis of the LD 102 and the collimator lens 110 are usually configured to coincide.

Here, as is well known, the LD 102 generates heat by emitting light. Therefore, the heat sink 10 which also serves as a holding member
4 is provided to prevent the LD 102 from being excessively heated. The heat radiating plate 104 needs to be formed of a material having high thermal conductivity in order to obtain good heat radiation efficiency, and is usually formed of a metal such as aluminum or brass.

However, there is some play between the holding hole 106 and the LD 102, and the heat sink 104 is
Since the LD 102 expands (shrinks) due to the heat generated by the laser beam 02, a change in the environmental temperature, and the like, the LD 102 slightly moves along with this, and the positions of the LD 102 and the collimator lens 110 relatively change. The LD 102 is a leaf spring 1
08, the LD 102 also moves when it receives vibration or the like from the outside, and the LD 102 also moves.
The position between 102 and the collimator lens 110 changes relatively.

When the relative position between the LD 102 and the collimator lens 112 changes in the scanning plane direction of the light beam, not only the position of the LD 102 changes but also the LD 10
When the light beam irradiated from 2 is incident off the optical axis of the collimator lens 110, this change is greatly enlarged on the scanned object. For example, with a commonly used laser exposure apparatus, a deviation of about 40 times occurs on the object to be scanned. That is, if the relative position between the LD 102 and the collimator lens 110 changes by 1 μm, the change in the scanning position of the light beam on the object to be scanned becomes about 40 μm.

One pixel in an image exposure apparatus usually has 60 pixels.
It is about μm. Therefore, in an apparatus for exposing a color image using three light beams, when the irradiation position of at least one light beam changes by 40 μm and the positional relationship of each light beam on the scanned object is changed, the color The result is a misaligned image. In addition, in the light source unit 100 having the above-described configuration, a fluctuation of about 10 μm at the maximum is sufficiently considered, and a larger deviation may occur.

On the other hand, the LD 102 and the collimator lens 11
If the relative position with respect to 0 changes in the depth of focus direction, that is, in the direction of travel of the light beam, the focus position changes, and the beam diameter on the scanned object changes, resulting in image blur and the like, resulting in a high-quality image. Can not be obtained.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art. In an image exposure apparatus using an LD as a light beam light source, the relative position between the LD and the collimator lens does not change, and the predetermined position is maintained. A method of assembling a semiconductor laser that enables a light beam having a beam diameter to be accurately incident on a predetermined position of a scanned object and perform high-quality image exposure without color shift even when exposing a color image. To provide.

[0016]

In order to achieve the above object, a method for assembling a semiconductor laser according to the present invention is a method for assembling a semiconductor laser used in an image exposure apparatus, wherein the semiconductor laser emits a laser beam. Is press-fitted into the holding hole of the radiator plate in which the holding hole for press-fitting and holding the semiconductor laser is formed, and then the radiator plate is cooled after heating.
Alternatively, there is provided a method for assembling a semiconductor laser characterized by heating, cooling, or heating after cooling.

[0017]

[0018]

The present invention relates to an image exposure apparatus by a raster scan using a semiconductor laser (LD) as a light source.
A radiator plate having a holding hole for press-fitting and holding an LD as a light source is used. The LD is pressed into the holding hole, and then the radiator plate is cooled and then heated, or cooled and then heated, or cooled or heated. It is.

As described above, in a conventional image recording apparatus to which an LD is applied, a light source unit having a configuration in which the LD is inserted into a holding hole formed in a heat radiating plate and held down by a leaf spring or the like is used. Used.

However, in this light source unit, residual stress generated when the LD is pressed is released due to expansion (shrinkage) of the heat radiating plate due to heat generation of the LD, a change in environmental temperature, or the like, or the LD is formed on the wall of the holding hole. Pushed, the position of the LD moves, and the relative position between the LD and the collimator lens changes, so that the irradiation position and the light beam diameter of the light beam on the scanned object change, In a color exposure apparatus that uses a scanning position shift on the object to be scanned or a three-LD, a color shift occurs due to a change in the relationship of the light beam irradiation position of each LD, and good image exposure is performed. There is a problem that can not be. Further, a change in the relative position between the LD and the collimator lens also occurs when an external impact is applied, and the same problem also occurs.

On the other hand, according to the semiconductor laser assembling method of the present invention, the LD is pressed into the holding hole of the heat sink,
This radiator plate is heated and cooled, or cooled and heated, or cooled or heated. That is, in the method of the present invention,
The LD is pressed into the holding hole to securely hold the LD in the radiator plate, and further, the radiator plate is cooled after heating, or cooled and then heated, or cooled or heated.
To release and stabilize the residual stress generated in the heat sink by press-fitting. Therefore, a change in the position of the LD due to temperature fluctuations of the LD and the environment, and also due to an external impact, is extremely small, and a change in the relative position between the LD and the collimator lens is extremely small. Changes in the position and beam diameter of the light beam on the scanning body are extremely small, and high-quality image exposure by accurate light beam scanning is possible.

[0022] Therefore, an image exposure apparatus, Rukoto using units made by assembling LD in this way the heat radiating plate
As a result, the expansion (shrinkage) of the heat radiating plate caused by a change in the environmental temperature is further reduced, and the LD and the collimator lens are caused to generate by the heat of the LD, a change in the environmental temperature, the expansion (shrinkage) of the heat radiating plate, and an external impact. The relative position between the LD and the collimator lens is fixed with high accuracy without changing the relative position, and extremely high-quality image exposure can be performed by accurate light beam scanning without color shift or the like.

Therefore, according to the present invention, it is possible to perform accurate image exposure with a small change in the scanning position and beam diameter of the light beam on the object to be scanned. And a good image free of defects can be obtained.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for assembling a semiconductor laser according to the present invention will be described below in detail with reference to preferred embodiments shown in the accompanying drawings.

FIG. 1 conceptually shows a perspective view of an example of an image exposure apparatus utilizing the semiconductor laser assembling method of the present invention.

The image exposure apparatus 10 shown in FIG. 1 includes light source units 12C, 12Y, 12E, which emit light having a wavelength and light output for producing C (cyan), Y (yellow), and M (magenta), respectively. 12M, the cylindrical lenses 18C, 18Y, and 18M, the reflecting mirror 20, the polygon mirror 22, the fθ A lens 24,
It is basically constituted by a 3LD light eccentric incidence optical system having a cylindrical mirror 26 and a sub-scanning conveyance unit (not shown) for sub-scanning and conveying the photosensitive material A.

In such an image exposure apparatus 10, the light beam deflected in the main scanning direction indicated by arrow a while the photosensitive material A is conveyed by the sub-scanning conveying means in the sub-scanning direction indicated by arrow b in FIG. 16C, 16Y, and 16M, the photosensitive material A is consequently scanned by each light beam for two light beams.
The image is exposed by performing dimensional scanning.

The image exposure apparatus 10 has a 3LD light eccentric incidence optical system. As a light source for emitting a light beam having a predetermined narrow band wavelength, light is projected onto the reflection surface 22a of the polygon mirror 22 at slightly different angles. It has three light source units 12C, 12Y, and 12M that emit beams.

The light source units 12C, 12Y and 12M are
The most characteristic member of the present invention, a semiconductor laser (hereinafter, referred to as an LD) as a light source is held on a heat sink using the semiconductor laser assembling method of the present invention, and is emitted from the LD. This is a unit formed by combining a collimator lens for shaping light into parallel light. For example, the light source unit 12C for coloring the cyan (C) dye of the photosensitive material A emits a light beam 16C having a wavelength of 810 nm, and the light source unit 12Y for coloring the yellow (Y) dye of the photosensitive material A emits a wavelength of 750 nm. Light beam 16Y
The light source unit 12M for coloring the magenta (M) dye of the photosensitive material A is a light beam 1 having a wavelength of 670 nm.
Inject 6M each. These light source units 12
C, 12Y, and 12M are controlled by an electric control system described later.

FIG. 2 shows a schematic front view (a) of a light source unit 12C that emits a light beam 16C, and a schematic cross-sectional view (b) thereof along the line bb. The light source unit 12
Y and 12M have the same configuration as the light source unit 12C except that the LD (specifically, the emission wavelength) to which they are applied is different.
Will be described as a representative example, and other description will be omitted.

The light source unit 12C is an LD 30 for emitting 810 nm laser light, which is a light source for the light beam 16C.
, A collimator lens 32, a lens barrel 34 of the collimator lens 32, a radiator plate 36 also serving as a holding member for the LD 30 and the lens barrel 34, and a radiator plate temperature holding mechanism 40. Note that, as described above, the light source units 12Y and 12Y
M differs only in the LD to which it is applied, and the light source unit 12Y is an LD that emits light of 750 nm, and the light source unit 12M is an LD that emits light of 670 nm, and each light source unit is formed. .

In the illustrated light source unit 12C, L
D30 is a heat radiating plate 3 which is a heat radiating member for the heat generated by itself.
6 and is held at a predetermined position. Here, the LD 30 is pressed and inserted into a slightly smaller holding hole 38 having the same shape as the LD 30 and then held and fixed in the holding hole 38 by heating / cooling, or cooling → heating, or cooling or heating the radiator plate 36. You.
Further, the heat radiating plate 36 is heated by the temperature holding mechanism 40 having the temperature measuring means (thermistor 42) and the heating means (power transistor 44) of the heat radiating plate, and the heat radiating plate 36 is maintained at a constant temperature.

That is, the LD 30 is held in the holding hole 38 itself by being pressed into the holding hole 38 slightly smaller than itself. Further, after the LD 30 is pressed into the holding hole 38, the heat radiation plate 36 is heated and then subjected to a heating / cooling process such as cooling, so that the residual stress of the heat radiation plate 36 caused by the press-fitting of the LD 30 is released and stabilized. The LD 30 can be stably held at a predetermined position against stress strain released by heat generation of the LD 30, thermal expansion of the heat radiating plate 36, and external vibration. Moreover, since the temperature of the heat radiating plate 36 is kept constant by the temperature holding mechanism 40, the position of the LD 30 does not move due to the thermal expansion (shrinkage) of the heat radiating plate 36. Furthermore, there is no wavelength fluctuation of the LD 30 due to temperature change,
Stable image exposure becomes possible.

As described above, in the conventional image exposure apparatus, the LD as the light source is inserted so as to be dropped into the holding hole formed in the heat radiating plate, and is radiated by being pressed from the back by a leaf spring or the like. In this method, the position of the LD moves due to the heat generated by the LD, the expansion (shrinkage) of the heat radiating plate due to the heat generated by the LD, the change in the environmental temperature, and the impact from the outside. , The relative position between the LD and the collimator lens changes, and the irradiation position and beam diameter of the light beam on the photosensitive material A change, so that good image exposure cannot be performed. In particular, in an apparatus such as the one shown in the drawing, in which exposure is performed by three light beams that respectively develop the C, M, and Y dyes of the photosensitive material A, if such inconvenience occurs, each light on the photosensitive material A is exposed. The irradiation positional relationship of the beam changes, resulting in a so-called color shift.

On the other hand, the light source unit 12 having the above configuration
In the image exposure apparatus 10 to which C (12Y, 12M) is applied, since the LD 30 can always be held at a predetermined position, the positions of the LD 30 and the collimator lens 32 do not relatively change. Good and high-quality image exposure can be performed without a change in the irradiation position or beam diameter of the light beam caused by the change.

The material for forming the heat radiating plate 36 is not particularly limited, and any material commonly used as a heat radiating plate for the LD 30, such as aluminum, brass, or copper, can be used.

The shape of the holding hole 38 formed in the heat sink 36 for holding the LD 30 is not particularly limited.
Depending on the shape, after the LD 30 is press-fitted, it may be a shape having at least a part capable of holding the LD 30 at a predetermined position with an appropriate force. In order to suitably prevent the change, it is preferable that the LD 30 be formed into a slightly smaller and same shape that can be press-fitted as shown in the illustrated example.

The present invention applied to the image exposure apparatus 10
In such a light source unit 12C, L
After the press-fit of D30, the radiator plate 36 is heated and then cooled. By this heating / cooling process, the residual stress generated in the heat radiating plate by the press-fitting of the LD 30 is released, and the movement of the LD 30 due to the stress distortion generated by the heat generation of the LD 30 is prevented. In the heating / cooling treatment, heating may be performed after cooling, or the treatment of only heating or only cooling has the effect of releasing residual stress.

The heating and cooling temperatures may be appropriately set within the range of the guaranteed maximum (lowest) temperature of the LD 30. Usually, heating is about 60 to 70 ° C. and cooling is about -20 to 10 ° C. It is preferable to perform a heating / cooling process at a temperature equal to or higher than the highest temperature (lower than the lowest temperature) of the radiator plate 36 in accordance with the environment (use environment, transport environment, etc.) where the image exposure apparatus will be placed. For example, the maximum guaranteed temperature is 85 ° C
In the case of an LD in which the assumed maximum temperature of the radiator plate 36 is about 60 ° C. and the minimum temperature is about 0 ° C., it is preferable to perform a heating process at 60 ° C. or more and a cooling process at 0 ° C. or less.

The time for the heating and cooling processing is determined by the length of the heat sink 36.
The time during which the residual stress of the substrate can be released may be appropriately set according to the heating (cooling) temperature, the residual stress, and the like.
The heating (cooling) treatment is performed for at least 8 hours, preferably at least 8 hours.

On the other hand, as a preferred embodiment, the collimator lens 32 is held by a lens barrel 34, and the lens barrel 34
Is held in a predetermined position by being placed in a V-shaped groove 46 formed in the heat sink 36.

The method of holding the collimator lens 32 by the lens barrel 34 is not particularly limited, and any known method applied to a camera or the like can be applied. The structure is such that the collimator lens 32 is bonded and fixed to the lens barrel 34 by bonding with an agent. By bonding and fixing the collimator lens 32 to the lens barrel 34, the collimator lens 32 does not move inside the lens barrel 34, so that the LD 30
And the collimator lens 32 can be held more reliably, and the position of the collimator lens 32 can be adjusted only by adjusting the position of the lens barrel 34.

The adhesive used for fixing the collimator lens 32 and the lens barrel 34 is not particularly limited. However, in terms of dimensional stability and workability, an epoxy-based adhesive or an ultraviolet-curable adhesive is used. Is preferably used.

The lens barrel 34 holding and fixing the collimator lens 32 in this manner is placed in a V-shaped groove 46 formed in the heat radiating plate 36 and fixed by a leaf spring 50. The leaf spring 50 is fixed to the heat radiating plate 36 by screws 48,48. That is, the light source unit 12 in the illustrated example
In C, the V-shaped groove 46 adjusts the position of the collimator lens 32 (barrel 34) in the photosensitive material A plane direction (main scanning and sub scanning directions). With such a configuration, if the dimensional accuracy of the V-shaped groove 46 is obtained at the time of manufacture, when the heat sink 36 and the lens barrel 34 are combined, the position of the lens barrel 34 in the photosensitive material A plane direction can be adjusted. This need not be performed, and the configuration and assembly of the light source unit 12C can be made extremely easy.

The shape such as the angle and depth of the V-shaped groove 46 is LD
The collimator lens 32 and L
What is necessary is just to determine suitably so that the optical axis with D30 may correspond.
In addition to the V-shape, various shapes such as an inverted trapezoidal shape and an elliptical shape that can position and mount the lens barrel 34 by applying the lens barrel 34 to two inclined surfaces can be applied. .

On the other hand, the collimator lens 32 (barrel 34)
May be performed by abutting one end surface of the lens barrel 34 on the heat radiating plate 36 as shown in the illustrated example, or alternatively, by positioning the lens barrel 34 in the V-shaped groove 46.
After adjusting by moving in this direction, it may be fixed by the leaf spring 50.

The light source unit 12C in the illustrated example has a temperature holding mechanism 40 for heating the heat radiating plate 36 and keeping it at a constant temperature.
Having. The temperature holding mechanism 40 includes a thermistor 42 as a temperature measuring unit, a power transistor 44 as a heating unit, an amplifier 52, an A / D converter 54, a microprocessor (hereinafter referred to as μP) 56, and a driver 58. The radiator plate 36 is heated by the power transistor 44 in accordance with the temperature measurement result by the thermistor 42 and is maintained at a constant temperature.

In the temperature holding mechanism 40, the thermistor 4
The measurement result signal of the heat radiating plate 36 by 2 is transferred to the amplifier 52. In the amplifier 52, a difference between the measurement result signal and a reference value (ground in the illustrated example) is detected, and then the detection result is converted into a digital signal by the A / D converter 54 and transferred to the μP 56. μP56
Receives the signal, sets (selects) the amount of heating by the power transistor 44, and transfers this signal to the driver 58. The driver 58 that has received the signal of the heating amount drives the power transistor 44 in accordance with the signal to drive the heat dissipation plate 36.
Is heated to maintain the heat sink 36 at a constant temperature.

By setting the temperature of the heat radiating plate 36 to a constant temperature by such a temperature holding mechanism 40, the LD 30 does not move due to the thermal expansion of the heat radiating plate 36, and the wavelength of the LD 30 does not fluctuate due to a temperature change. Exposure becomes possible. In particular, in an image exposure apparatus that applies three light beams (LD) as shown in the illustrated example, the irradiation positions of the light beams emitted from the respective light source units do not change. Since it is possible to maintain a constant relationship without color shift, it is possible to expose a high-quality color image without color shift. Further, by keeping the temperature of the LD constant, there is also an effect that the electrical characteristics of the LD are stabilized.

The temperature measuring means and the heating means applied to the temperature holding mechanism 40 are not limited to the thermistor 42 and the power transistor 44, and any of various known temperature measuring and heating means can be applied.

It is preferable that the temperature holding mechanism 40 is individually arranged for each of the light source units 12C, 12Y and 12M, and measures the temperature and temperature of the radiator plate 36, respectively. Measure the temperature of the heat sink 36,
Based on this, the configuration may be such that the temperature of the heat radiating plates 36 of the three light source units is maintained.

The light source unit 12C shown in FIG.
Although the D30 and the lens barrel 34 are held by the heat radiating plate 36, the light source unit applied to the present invention is not limited to this, and the heat radiating plate may be configured to hold and fix only the LD. . However, since the relative position between the LD and the collimator lens 32 can be more securely held, the heat sink 36 integrally molded as shown in the illustrated example is used.
It is preferable that the LD 30 and the lens barrel 34 are held by the above, and the temperature of the heat radiating plate 36 is further held.

In the image exposure apparatus 10 shown in FIG. 1, the light source units 12C, 12Y and 12M for emitting the light beams 16C, 16Y and 16M are individually formed, but the present invention is not limited to this. Instead, three types of LDs and a collimator lens are incorporated in one heat sink,
A light source unit that emits three light beams 16C, 16Y, and 16M may be integrally formed. In this case, the temperature holding unit 40 may be a unit that performs heating by one power transistor 44, or may be a unit that applies a plurality of power transistors 44 corresponding to each LD.

The light beams 16C, 16Y, 16M emitted from the light source units 12C, 12Y, 12M enter the cylindrical lenses 18C, 18Y, 18M. The cylindrical lenses 18C, 18Y, and 18M, the fθ lens 24, and the cylindrical mirror 26 constitute a surface tilt correction optical system, and corrects the surface tilt of the polygon mirror 22.

Here, the light source units 12C, 12Y, 1
Emitted from 2M, cylindrical lenses 18C, 18
Light beams 16C, 16Y, 16M that have passed through Y, 18M
Are reflected by the mirror 20 in a predetermined direction and are incident on the reflecting surface 22a of the polygon mirror 22 at slightly different angles, and are reflected by the reflecting surface 22a and differ on the same main scanning line SL on the photosensitive material A. An image is formed at an angle, and scanning is performed on the same main scanning line SL at intervals in time. Therefore, the light source units 12C, 12Y, and 12M are arranged at a predetermined angle, and the reflection mirror 20 outputs the light beams 16C, 16C.
The light paths of Y and 16M are changed, and these are all incident on a position close to or substantially on the same line on the reflection surface 22a of the polygon mirror 22.

The fθ lens 24 outputs the light beams 16C, 1
This is for correctly forming an image of 6Y and 16M at any position of the main scanning line SL. Note that the fθ lens 24 is corrected so that chromatic aberration of light having wavelengths of 670, 750, and 810 nm falls within an allowable range.
The cylindrical mirror 26 is used for the cylindrical lens 1.
8C, 18Y, 18M and the fθ lens 24 constitute a surface tilt correction optical system, and each light beam 16C, 16Y, 1
6M is lowered, and the photosensitive material A is transported in the sub-scanning direction.
The light is incident on the photosensitive material A toward a main scanning line SL substantially orthogonal to the upper sub-scanning direction.

Here, since the photosensitive material A is conveyed in the sub-scanning direction by a sub-scanning conveying means (not shown), the light beams 16C, 16Y, and 16M deflected in the main scanning direction.
Scans the photosensitive material A two-dimensionally and performs image exposure.

The control of such image exposure by the light beams 16C, 16Y and 16M, that is, the light source unit 12
The emission of the light beams by C, 12Y and 12M is controlled by the drive circuits 14C, 14Y and 14M and the image signal source 28.

The driving circuits 14C, 14Y, and 14M are driving circuits for driving the light source units 12C, 12Y, and 12M. In the case of pulse width modulation, each of the driving circuits 14C, 14Y, and 14M is provided for each LD for a time set for each pixel. Drive current for the light output set in advance to the light source units 12C, 12Y, and 12M.
Pour into As a result, the light source units 12C, 12Y, 12
M is an optical output preset for each LD, and each L
D emits light for a time determined according to the i-pixel. This is performed over one line, and the light source unit 1
2C, 12Y, and 12M perform one-line exposure.

The driving circuits 14C, 14Y and 14M are connected to an image signal source 28. The image signal source 28 receives the input timing of the image information signal for one line to the drive circuits 14C, 14Y, and 14M, the light source units 12C, 12Y,
It controls 12M light emission timing (pixel clock timing) and the like, or receives various signals to perform various controls required for the image exposure apparatus.

Although the method of assembling the semiconductor laser according to the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and may be made within the scope of the present invention.
Of course, various improvements and changes may be made.

[0062]

As described above in detail, according to the present invention, since the relative position between the LD as the light beam light source and the collimator lens does not change, the light beam on the object to be scanned is not changed. Accurate image exposure without deviation in scanning position and beam diameter can be performed. Particularly, in the case of a color image to which a plurality of light beams are applied, a good image without color shift or the like can be obtained.

[Brief description of the drawings]

FIG. 1 shows a method for assembling a semiconductor laser according to the present invention.
It is a schematic perspective view showing an example of an image exposure apparatus for.

2A is a schematic front view of a light source unit applied to the image exposure apparatus shown in FIG. 1, and FIG.
It is a line schematic sectional drawing.

FIG. 3 is a schematic sectional view of a light source unit applied to a conventional image exposure apparatus.

[Explanation of symbols]

 Reference Signs List 10 image exposure apparatus 12C, 12Y, 12M light source unit 14C, 14Y, 14M drive circuit 16C, 16Y, 16M light beam 18C, 18Y, 18M cylindrical lens 20 mirror 22 polygon mirror 24 fθ lens 26 cylindrical mirror 28 image signal source 30 semiconductor laser (LD) 32 collimator lens 34 lens barrel 36 heat sink 38 holding hole 40 temperature holding means 42 thermistor 44 power transistor 46 V-shaped groove 48 screw 50 leaf spring 52 amplifier 54 A / D converter 56 microprocessor (μP) 58 driver

Claims (1)

(57) [Claims] 1. A method for assembling a semiconductor laser used in an image exposure apparatus, comprising: a holding hole of a heat sink having a holding hole for press-fitting and holding the semiconductor laser for emitting a laser beam; And then cooling the radiator plate after heating, or heating after cooling, or cooling or heating.