JP3408105B2 - Light source device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source device used for an image recording device such as a laser beam printer or a laser facsimile, or a pickup unit for an optical disk using a semiconductor laser.

[0002]

2. Description of the Related Art Optical deflection scanning devices used in image recording devices such as laser beam printers and laser facsimiles,
A light source device such as an optical disk pickup unit using a semiconductor laser includes a collimator lens for collimating laser light generated from the semiconductor laser to obtain laser light having a predetermined cross-sectional shape, a semiconductor laser driving IC, and the like. It is united with the mounted circuit board. In an image recording device, a laser beam generated from a unitized light source device is applied to a rotary polygon mirror through a cylindrical lens, and the obtained scanning light is exposed on a rotary drum through an imaging lens and a folding mirror. Focus on the body. The laser light imaged on the photoconductor forms an electrostatic latent image with the main scanning by the rotation of the rotary polygon mirror and the sub-scanning by the rotation of the rotary drum.

The light source device, the rotary polygon mirror, the imaging lens, the folding mirror, etc. are attached to a housing such as an optical box, and the upper opening of the housing is closed by a lid.

FIG. 6 shows a light source device according to a conventional example, which includes a laser holder 102 having a press-fitting hole 102a into which a semiconductor laser 101 is press-fitted, and a screw 10.
3, the circuit board 104 screwed to the laser holder 102, the lens holder 105 that fits into the cylindrical portion 102b of the laser holder 102, and the lens holder 105.
The circuit board 104 is screwed to the laser holder 102 as described above, and the laser holder 102 is screwed to the housing H ₀ by the screw 107 as described above.

The lens holder 105 is the laser holder 10
The second cylindrical portion 102b has a cylindrical portion 105a fitted externally and a collimator lens holding portion 105b holding the collimator lens 106. Cylindrical portion 105 of lens holder 105
The a and the cylindrical portion 102b of the laser holder 102 are adhered to each other by a photocurable adhesive or the like introduced between them. The cylindrical portion 105a of the lens holder 105 is made of a transparent material such as transparent plastic for transmitting light for curing the adhesive, or a material having a property of transmitting the light while blocking the laser light. Collimator lens holding portion 105b of the lens holder 105
Is a cylindrical portion that holds the collimator lens 106, and a diaphragm opening 108 at a position close to the collimator lens 106.
It is made of a colored plastic material or the like that shields the laser light.

That is, the cylindrical portion 1 of the lens holder 105.
05a and the collimator lens holding unit 105b are, for example,
The transparent plastic material and the colored plastic material are integrally molded by two-color molding, and a flange portion 105c projecting outward in the radial direction is integrally formed at a joint portion of the cylindrical portion 105a and the collimator lens holding portion 105b. It is provided in.

In assembling the light source device, before the lens holder 105 is bonded to the laser holder 102 with the adhesive as described above, the cylindrical portion 1 of the lens holder 105 is used.
05a and the cylindrical portion 102b of the laser holder 102 allow the lens holder 105 to move in a direction orthogonal to the optical axis of the laser light within a range allowed by the clearance so that the optical axis of the collimator lens 106 coincides with the optical axis of the laser light. The so-called optical axis alignment and the focusing process of the collimator lens 106 that axially moves the cylindrical portion 105a of the lens holder 105 along the tubular portion 102b of the laser holder 102 are required. Focusing is
Along with the subsequent adhering step and the like, the automatic assembling apparatus M ₀ shown in FIG. 8 is used to carry out automatically and continuously.

The automatic assembling apparatus M ₀ includes a laser holder 102 and a circuit board 10 which are screwed together by screws 103.
Laser holder jig C ₀ for fixing the unit No. 4 in a fixed position on the support surface F ₀ and lens holder jig D ₀ for holding the lens holder 105 having the collimator lens 106 built therein.
And an optical measuring device E ₀ for measuring the focal position and the optical axis position of the laser light. The lens holder jig D ₀ is a support surface F between the laser holder jig C ₀ and the optical measuring device E _0.
0 is movable on the X-axis direction orthogonal to the optical axis direction (Z axis direction).

The lens holder jig D ₀ is moved to the right in the drawing, the lens holder 105 is put on the cylindrical portion 102b of the laser holder 102, and the semiconductor laser 101 held by the laser holder 102 is caused to emit light, The jig D ₀ is moved in the X-axis direction to move the collimator lens 10
6 optical axis alignment, then lens holder jig D
_By moving ₀ in the Z-axis direction, the collimator lens 10
6. Focusing is performed. After the optical axis alignment and the focusing have been completed in this way, a photo-curing adhesive is injected between the lens holder 105 and the cylindrical portion 102b of the laser holder 102, and light is irradiated to cure the adhesive. Let

The flange portion 105c of the lens holder 105
Is used for fixing the lens holder 105 to the lens holder jig D ₀ when assembling the light source device by the automatic assembling apparatus M ₀ . The lens holder jig D ₀ is shown in FIG.
, A block B ₀ having a circular hole B ₁ and a rectangular recess B ₂ , a pressing member G _0, and a pair of clamp claws J.
_1, includes a J _2, the collimator lens holding portion 105b of the lens holder 105 is loosely fitted in the circular hole B ₁ block B _0, the one surface of the flange portion 105c on the bottom surface of the recess B ₂ block B ₀ person The pressing member G ₀ is pressed against the side edge of the flange portion 105c so that the flange portion 105c of the lens holder 105 is connected to the side surface of the recess B ₂ of the block B _0.
Is clamped in the X-axis direction. In this way, the lens holder 1
05 in the XY plane, and clamp claw J
_1, by J ₂ by pressing the flange portion 105c of the lens holder 105 to the bottom surface of the recess B ₂ block B _0, to position the Z-axis direction.

[0011]

However, according to the above-mentioned conventional technique, as described above, the flange portion used for fixing the lens holder to the lens holder jig projects from the cylindrical portion of the lens holder in the radial direction. Since it is a deformed portion, the shape of the entire lens holder is complicated and it is difficult to obtain sufficient processing accuracy, and the configuration of the lens holder jig for clamping this is also complicated. Further, when the light source device unitized by assembling the lens holder to the laser holder is attached to the housing such as an optical box, the opening A ₀ (see FIG. 6) is penetrated from the outside of the housing and the lens is inserted inside. It is necessary to insert the holder. Therefore, the opening A ₀ must be provided at least locally with a width sufficient for passing the flange portion of the lens holder, and after the light source device is assembled, the opening is not opened. A part of the portion A ₀ remains open, leading to troubles such as intrusion of dust in the outside air.

The present invention has been made in view of the above-mentioned unsolved problems of the prior art. It is easy to attach a lens holder to a jig of an automatic assembling apparatus, and a flange portion or the like protruding in a radial direction is provided. It is an object of the present invention to provide a light source device capable of significantly reducing both the assembly cost and the component cost because it is not necessary to provide the lens holder with the odd-shaped portion.

[0013]

In order to achieve the above object, a light source device of the present invention comprises a light source holding means for holding a light source and a collimator lens for collimating a light beam generated from the light source. And a cylindrical lens holder incorporating the collimator lens, and the lens holder is provided with an orientation flat surface having a part of the cylindrical surface thereof flattened.

It is preferable that the lens holder has a lens supporting portion for supporting the collimator lens and an annular portion arranged outside thereof, and the orientation flat surface is provided on the annular portion.

A gap may be provided between the lens support portion of the lens holder and the annular portion outside the lens support portion.

The annular portion of the lens holder may be made of metal.

[0017]

In the step of unitizing the light emitting source holding means such as the laser holder and the lens holder holding the collimator lens by the automatic assembling device, the lens holder is mounted by using the cylindrical surface of the lens holder and the orientation flat surface provided on the cylindrical surface. It is fixed to the lens holder jig and the optical axis and focus of the collimator lens are adjusted.

Since the lens holder does not need a deformed portion such as a flange portion which projects in the radial direction, the shape of the lens holder is simple. Moreover, the lens holder jig also
Since only a block having two abutting surfaces that support the cylindrical surface of the lens holder and a pressing member that is pressed against the orientation flat surface are required, the structure is simple and the number of driving units is small.

As a result, the parts cost and the assembly cost of the light source device can be greatly reduced.

If the lens holder has a lens support portion for supporting the collimator lens and an annular portion disposed outside the lens support portion, and if the orientation flat surface is provided on the annular portion, the lens support portion and the annular portion are provided. By providing a gap between them or manufacturing the annular portion with a highly rigid material such as metal, troubles such as damage to the collimator lens due to external force or impact during the assembly work of the light source device can be avoided. As a result, the efficiency of assembly work can be significantly improved.

[0021]

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

FIG. 1 shows a light source device according to an embodiment, which includes a laser holder 2 which is a light emitting source holding means having a press-fitting hole 2a into which a semiconductor laser 1 which is a light emitting source is press-fitted in a central portion, The circuit board 4 is screwed to the laser holder 2 with the screw 3, the lens holder 5 is fitted in the cylindrical portion 2b of the laser holder 2, and the collimator lens 6 is held by the lens holder 5. After the circuit board 4 is screwed to the laser holder 2 as described above, the laser holder 2 is screwed to the housing H ₁ with the screw 7.

The lens holder 5 is a lens supporting portion for holding the cylindrical portion 5a fitted on the cylindrical portion 2b of the laser holder 2 and the collimator lens 6, and the collimator lens holding portion 5.
b. The cylindrical portion 5a of the lens holder 5 and the cylindrical portion 2b of the laser holder 2 are adhered to each other with an adhesive such as a photo-curing adhesive introduced between them. The cylindrical portion 5a of the lens holder 5 is made of a transparent material such as transparent plastic for transmitting the light that cures the adhesive, or a material having a property of transmitting the light while blocking the laser beam which is a light beam. Produced. The collimator lens holding portion 5b of the lens holder 5 includes a cylindrical portion that holds the collimator lens 6 and a diaphragm-shaped portion that forms a diaphragm opening 8 in a position close to the collimator lens 6, and is colored to block laser light. It is made of plastic material.

That is, the cylindrical portion 5a of the lens holder 5 and the collimator lens holding portion 5b are integrally formed by, for example, two-color molding of a transparent plastic material and a colored plastic material, and the outside of the collimator lens holding portion 5b. An annular grip portion 5c, which is an annular portion coaxial with this and located on an extension of the cylindrical portion 5a, is integrally provided. The annular grip portion 5c is coaxially arranged outside the collimator lens holding portion 5b, and its axial length is longer than that of the collimator lens holding portion 5b.
It is a substantially cylindrical member having the collimator lens holding portion 5b built-in, and a part of the cylindrical surface is flattened so that the orientation flat surface 5 is formed.
composing d.

In assembling the light source device, the clearance between the cylindrical portion 5a of the lens holder 5 and the cylindrical portion 2b of the laser holder 2 is allowed before the lens holder 5 is bonded to the laser holder 2 with the adhesive as described above. Within the range, the lens holder 5 is moved in a direction orthogonal to the optical axis of the laser light so that the optical axis of the collimator lens 6 coincides with the optical axis of the laser light, and the so-called optical axis alignment of the lens holder 5 is performed. A step of focusing the collimator lens 6 that moves in the axial direction along the cylindrical portion 2b of the holder 2 is required, and such optical axis focusing and focusing together with the subsequent bonding step and the like are shown in FIG. Automatic assembly device M shown
Automatically and continuously using ₁ .

The automatic assembling apparatus M ₁ has a laser holder jig C for fixing the unit of the laser holder 2 and the circuit board 4 screwed to each other by a screw 3 in a fixed position on the supporting surface F _1.
1 , a lens holder jig D ₁ for holding the lens holder 5 containing the collimator lens 6, and an optical measuring device E ₁ for measuring the focal position and the optical axis position of the laser light.
The lens holder jig D ₁ is movable between the laser holder jig C ₁ and the optical measuring device E ₁ on the support surface F ₁ in the optical axis direction (Z axis direction) and the X axis direction orthogonal thereto. is there.

The lens holder jig D ₁ is moved to the right in the drawing, the lens holder 5 is put on the cylindrical portion 2b of the laser holder 2, and the semiconductor laser 1 held by the laser holder 2 is moved.
, While moving the lens holder jig D ₁ in the X-axis direction to align the optical axis of the collimator lens 6.
Subsequently, the lens holder jig D ₁ is moved in the Z-axis direction to focus the collimator lens 6. After completing the optical axis alignment and focusing in this way,
A photo-curable adhesive is injected between the lens holder 5 and the cylindrical portion 2b of the laser holder 2 and irradiated with light to cure the adhesive.

The annular grip portion 5c of the lens holder 5 is used to fix the lens holder 5 to the lens holder jig D ₁ when the light source device is assembled by the automatic assembling apparatus M ₁ . As shown in FIG. 2, the lens holder jig D ₁ includes a block K having _first and _second contact surfaces K ₁ and K ₂ that contact the cylindrical surface of the annular grip portion 5c of the lens holder 5. , A pressing member G that is brought into contact with the orientation flat surface 5d of the annular grip portion 5c.
Having _one .

The abutting surfaces K ₁ and K ₂ of the block K are formed at the bottom of a V-shaped notch formed in the side surface of the block K, and the side surface of the notch has an annular shape of the lens holder 5. Third contact surface K with which the end surface (free end) of the grip portion 5c abuts
_Make up _three . The annular grip portion 5c of the lens holder 5 having the collimator lens 6 incorporated therein is inserted into the notch portion of the block K, and the first and second contact surfaces K ₁ and K ₂ of the block K and the third contact surface 3
On the contact surface K ₃ of the lens holder 5 respectively.
The cylindrical surface of c is brought into contact with the end surface, and the pressing member G ₁ is driven in the Y-axis direction by, for example, an air cylinder or a spring to press the orientation flat surface 5d of the lens holder 5. by this,
The annular grip portion 5c of the lens holder 5 is sandwiched between the block K and the pressing member G ₁ , and is firmly gripped at a predetermined optical axis position and rotation position.

In this way, the lens holder 5 is held by the lens holder jig D ₁ and is moved toward the laser holder 2 held by the laser holder jig C ₁ as described above to assemble the lens holder 5. Do.

According to this embodiment, the annular holding portion for holding the lens holder on the lens holder jig is on the extension of the cylindrical portion of the lens holder and has the same outer diameter as that of the cylindrical portion. The outer diameter of the orientation flat surface, which is a part of the flattened surface, is smaller than the outer diameter of the cylindrical part of the lens holder, so the housing that is required when the light source device is unitized and then assembled from the outside of the housing The opening A ₁ (see FIG. 1) of
The size may be such that it penetrates the cylindrical portion of the lens holder. There is no need to unnecessarily increase the size of the opening for penetrating the flange that protrudes in the radial direction as in the past, and some problems such as the intrusion of outside air after the light source device has been partially assembled are left open. Nor.

Further, the shape of the annular grip portion of the lens holder is an extremely simple shape in which a part of the cylinder is flattened to form an orientation flat surface, so that the lens holder can be processed easily and the cost of parts is low. In addition, the structure of the lens holder jig is simple and the number of driving parts is small, so that the cost and accuracy of the lens holder jig can be greatly promoted. Further, the work of mounting the lens holder on the lens holder jig is extremely easy, and the positioning accuracy is high. As a result, the manufacturing cost of the light source device can be greatly reduced.

Further, the collimator lens holding portion for holding the collimator lens is arranged inside the annular holding portion of the lens holder, and a gap is formed between them, and moreover, the collimator lens is provided from the free end of the lens holder. Is held in the retracted state, it is possible to avoid the operator's hand or the like from coming into contact with the collimator lens during the assembly work of the light source device. Also, when the lens holder jig holds the lens holder, the gripping force of the lens holder jig acts only on the annular gripping portion outside the collimator lens holding portion of the lens holder, so the gripping force of the lens holder jig Does not adversely affect the collimator lens, and also has an effect of preventing external force, impact, etc. during the assembly of the light source device from propagating to the collimator lens.

When the lens holder is set on the lens holder jig, even if the lens holder is inserted into the block in a state where the rotation position of the orientation flat surface of the lens holder is slightly shifted, the pressing member is automatically pushed by pressing the orientation flat surface. The rotational position of the lens holder is corrected accordingly. Therefore, there is also an advantage that the work of mounting the lens holder on the lens holder jig is extremely simple.

FIG. 4 shows a lens holder 25 according to a modification. In this case, the collimator lens holding portion 25b of the lens holder 25 is in close contact with an annular grip portion 25c made of a highly rigid material such as metal, and the outer diameter of the cylindrical portion 25a of the lens holder 25 is small. This is suitable when an annular gap cannot be provided between the annular grip portion 25c and the collimator lens holding portion 25b having the same outer diameter.

By making the annular grip 25c highly rigid,
It is possible to prevent the gripping force, which is generated when the orientation flat surface 25d is gripped by the lens holder jig, from propagating to the collimator lens 26 via the collimator lens holding portion 25b.

FIG. 5 shows a light source device 50 according to this embodiment.
FIG. 1 shows the entire optical deflection scanning device used for the above, which collects a light beam (laser light) generated from the rotating polygon mirror 51 and the semiconductor laser of the light source 50 linearly on the reflecting surface of the rotating polygon mirror 51. It has a cylindrical lens 51a for emitting light, and deflects and scans the light beam by rotating the rotary polygon mirror 51, and forms an image on a photoconductor 54 on a rotating drum through an imaging lens 52 and a folding mirror 53. Imaging lens 5
Reference numeral 2 has a spherical lens portion 52a, a toric lens portion 52b, and the like, and has a so-called fθ function of correcting the scanning speed and the like of the point image formed on the photoconductor 54.

When the rotary polygon mirror 51 is rotated by the motor, its reflecting surface rotates at a constant speed around the axis of the rotary polygon mirror 51 as indicated by arrow A. As described above, the angle formed by the optical path of the light beam condensed by the cylindrical lens 51a and the normal line of the reflecting surface of the rotating polygon mirror 51, that is, the incident angle of the light beam on the reflecting surface, is the rotating polygon mirror 51.
Changes with time and the reflection angle also changes, so that the point image formed by condensing the light beam on the photoconductor 54 moves in the direction indicated by the arrow Y (main scanning direction).

The imaging lens 52 condenses the light beam (scanning light) reflected by the rotary polygon mirror 51 into a spot image of a predetermined spot shape on the photosensitive member 54, and moves the spot image in the main scanning direction. Is a compound lens designed to maintain a constant scanning speed of.

The point image formed on the photosensitive member 54 is electrostatically accompanied by the main scanning by the rotation of the rotary polygon mirror 51 and the sub-scanning by the rotation of the rotary drum having the photosensitive member 54 around its axis. Form a latent image.

Around the photoconductor 54, a corona discharger is provided for uniformly charging the surface of the photoconductor 54, and an electrostatic latent image formed on the surface of the photoconductor 54 is visualized as a toner image. And a corona discharger for transfer (not shown) for transferring the toner image onto recording paper or the like are arranged, and recording information by a light beam generated from the semiconductor laser of the light source 50 is recorded on the recording paper or the like. Printed.

The detection mirror 55 reflects the light beam on the upstream side in the main scanning direction with respect to the optical path of the light beam incident on the recording information writing start position Y ₁ on the photosensitive member 54.
The light is introduced into the light receiving surface of the light receiving element 56b having a photodiode or the like through the condenser lens 56a. Light receiving element 56b
Outputs a scanning start signal for detecting a scanning start position (writing position) when the light receiving surface is illuminated by the light beam.

The condenser lens 56a and the light receiving element 56b are arranged between the imaging lens 52 and the rotary polygon mirror 51, and the detection mirror 55 reflects the light beam below the scanning surface of the scanning light.

The semiconductor laser of the light source 50 generates a light beam corresponding to the signal given from the processing circuit 57 for processing the information from the host computer. The signal given to the semiconductor laser corresponds to the information to be written in the photoconductor 54, and the processing circuit 57 provides the information corresponding to one scanning line which is the locus formed by the point image formed on the surface of the photoconductor 54. The expressed signal is given to the semiconductor laser as one unit. This information signal is transmitted in synchronization with the scanning start signal given from the light receiving element 56b through the line 56c.

[0045]

Since the present invention is constructed as described above, it has the following effects.

When the lens holder is assembled to the laser holder or the like, it is easy to attach the lens holder to the jig of the automatic assembling apparatus, and it is not necessary to provide the lens holder with a deformed portion such as a flange portion. In other words, the shape of the lens holder is simple and the cost of parts is low, and the work of attaching the lens holder to the automatic assembling apparatus is also easy, so that the assembling cost is low. This makes it possible to realize an inexpensive light source device.

By using such a light source device, it is possible to greatly contribute to the cost reduction of the image forming apparatus and the like.

[Brief description of drawings]

FIG. 1 shows a light source device according to an embodiment, (a)
Is a schematic sectional view thereof, (b) is an elevational view showing only a lens holder, and (c) is a schematic sectional view showing a lens holder incorporating a collimator lens.

2A and 2B show a lens holder jig, in which FIG. 2A is an elevation view thereof and FIG. 2B is a sectional view thereof.

FIG. 3 is a diagram illustrating an automatic assembly device.

FIG. 4 shows a lens holder according to a modification,
(A) is the elevation view, (b) is sectional drawing.

FIG. 5 is a diagram illustrating an entire optical deflection scanning device.

FIG. 6 shows a light source device according to a conventional example, (a)
Is a schematic sectional view thereof, (b) is an elevational view showing only a lens holder, and (c) is a sectional view showing a lens holder incorporating a collimator lens.

7A and 7B show a lens holder jig for holding the lens holder of FIG. 6, in which FIG. 7A is a sectional view thereof, and FIG.

8 is a diagram illustrating an automatic assembling apparatus that assembles the light source device of FIG.

[Explanation of symbols]

1 Semiconductor laser 2 Laser holder 4 circuit board 5,25 lens holder 5b, 25b Collimator lens holder 5c, 25c annular grip 5d, 25d orientation flat surface 6,26 Collimator lens 50 light sources 51 rotating polygon mirror

Claims (5)

(57) [Claims] 1. A light source holding means for holding a light source, a collimator lens for collimating a light beam generated from the light source, and a cylindrical lens holder containing the collimator lens. A light source device, wherein the holder is provided with an orientation flat surface in which a part of the cylindrical surface is flattened. 2. The lens holder has a lens support portion for supporting the collimator lens and an annular portion provided outside the lens support portion, and the annular portion is provided with an orientation flat surface. 1. The light source device according to 1. 3. The light source device according to claim 2, wherein a gap is provided between the lens support portion of the lens holder and an annular portion outside the lens support portion. 4. The light source device according to claim 2, wherein the annular portion of the lens holder is made of a highly rigid material. 5. The light source device according to claim 2, wherein the annular portion of the lens holder is made of metal.