JP2001111155A - Light source device and optical beam scanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device capable of holding fluctuations of an optical element such as a collimator lens, etc., to the utmost. SOLUTION: In a pedestal 112 of a light source device, there are provided a V-shaped groove 114 for holding a mirror cylinder 131 provided internally with a collimator lens, and through holes 121, 123 piercing between the V-shaped groove 114 and a side surface of the pedestal 112. After the mirror cylinder 131 is mounted on the V-shaped groove 114, and an optical positional adjustment is made with respect to the laser diode, laser beams for laser welding are locally irradiated via the through holes 121, 123 on a contact part P of an opening on a side of the V-shaped groove 114 of the through holes 121, 123 with an outer peripheral surface of the mirror cylinder 131 to make laser welding, and the mirror cylinder 131 is fixed to the pedestal 112.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a light source device and a light beam scanning device.

[0002]

2. Description of the Related Art A laser beam scanning device used in an image forming apparatus such as a digital copying machine or a laser printer generally includes a light source device including a laser diode, a collimator lens, a cylindrical lens, a polygon mirror, a scanning lens, a folding mirror, and the like. It has. A laser beam emitted from a laser diode driven according to an image signal is converged to parallel light by a collimator lens, then converged only in the sub-scanning direction by a cylindrical lens, and reflected by a mirror surface of a rotating polygon mirror. The beam is deflected and scanned. Then, the surface of the photosensitive drum is exposed and scanned via a scanning lens, a folding mirror, and the like to form an electrostatic latent image.

In order to obtain good quality images using such a laser beam scanning device, exposure scanning with a laser beam is performed at a predetermined position on a photosensitive drum, and a beam spot at the time of exposure scanning is used. An image needs to be formed in a predetermined state. Therefore, in the manufacturing stage of the image forming apparatus, for example, a lens barrel holding a collimator lens is temporarily fixed to a base on the light source device,
The laser diode is actually driven, and the position of the lens barrel (collimator lens) is finely adjusted until the beam spot on the photosensitive drum is properly imaged at a predetermined position. Upon completion, the lens barrel is fixed to the base by screwing or bonded by an adhesive.

Such a fixing method is also used for fixing other optical elements such as a cylindrical lens and a laser diode as a light emitting element.

[0005]

However, the conventional method of simply fixing or bonding an optical element or the like on a base by screwing has a problem that the position of the optical element fluctuates from the adjustment position. That is, for example, when the barrel of the collimator lens is fixed by screwing, the torque in the rotating direction is reduced when the screw is tightened, despite the fact that the position of the collimator lens was precisely adjusted by then. And the position of the lens barrel deviates from the adjustment position,
Residual distortion is generated in the screw itself and the lens barrel, and the screw and the lens barrel are deformed with the lapse of time due to this action, and the position of the lens barrel changes. In addition, in the case of bonding, in order to strengthen the bonding, it is usually performed to apply a large amount of adhesive to a contact portion between the lens barrel and the base, and the solidification is performed. The adhesive contracts and expands due to fluctuations in temperature and humidity, thereby changing the position of the lens barrel.

If the position of the lens barrel changes, the distance between the collimator lens and the laser diode changes, or the laser emission point shifts from the position on the optical axis of the collimator lens, and the convergence state of the laser beam changes. However, the beam spot image at the time of exposure scanning on the photosensitive drum is blurred, or the exposure scanning position of the laser beam is deviated from a predetermined position, so that an electrostatic latent image that is faithful to the original image cannot be formed, resulting in poor image quality. It will deteriorate.

Such a problem can also occur in the case where the light source device itself is fixed on the base of the laser beam scanning device by the above-described method. The present invention
The present invention has been made in view of the above-described problems, and has as its object to provide a light source device and a light beam scanning device capable of minimizing positional fluctuation of a collimator lens and the like.

[0008]

According to the present invention, there is provided a light source device for irradiating an object with a light beam emitted from a light emitting element through an optical element, wherein the optical element holds the light element. The light emitting element is fixed to the base of the light source device by laser welding in a state where the light emitting element is optically adjusted in position.

A light source device for irradiating an object with a light beam emitted from a light emitting element through an optical element,
A holding frame for holding the optical element, wherein the holding frame includes:
In a state where the light emitting element and the optical position adjustment have been performed, on a plane orthogonal to the optical axis of the optical element and in a plane including the position of the principal point of the optical element or in a plane close to the plane , And is fixed to a base of the light source device.

A light source device comprising a light emitting element mounted on a stem and a circuit board for supplying a drive current to the light emitting element, wherein the bottom surface of the stem is directly soldered to the circuit board or It is characterized by being fixed by laser welding. Also, a light source device including a light emitting element mounted on a stem and a holding member for holding the stem, wherein the stem is fixed to the holding member by laser welding in a state where optical position adjustment is performed. It is characterized by having been done.

The light source unit includes a light emitting element, a collimator for collimating a light beam emitted from the light emitting element, and a deflector for deflecting the light beam from the light source unit to scan an object to be scanned. A light beam scanning device, wherein the light source unit is fixed to a base portion of the light beam scanning device by laser welding.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a light source device and a light beam scanning device according to the present invention will be described as an example in which the present invention is applied to a monochrome laser printer (hereinafter simply referred to as a "printer"). (Mounting Structure of Lens Barrel) FIG. 1 is a view showing a schematic configuration of the entire printer.

The printer reproduces an image on a recording sheet based on image data input from an external device such as a personal computer. When image data is input from an external device, the control unit 1 converts the image data into a drive signal for a laser diode, and drives a laser diode 12 (FIG. 2) inside a printer head 10 used as a light beam scanning device. The laser diode 12
After being deflected by the folding mirror 2, the surface of the photosensitive drum 4 is exposed in the main scanning direction.

Around the photosensitive drum 4, a drum cleaner 5, an eraser lamp 6, a charging charger 7, a developing device 8
And a transfer charger 9. Photoconductor drum 4
Before the exposure with the laser beam L, the residual toner is removed by the drum cleaner 5, the charge is removed by the eraser lamp 6, and the charge is uniformly charged by the charging charger 7. When the charged surface of the photosensitive drum 4 is exposed, an electrostatic latent image is formed, and this electrostatic latent image is visualized as a toner image by the developing device 8.

On the other hand, a recording sheet (not shown) is fed from a sheet feeding cassette 20 by a pickup roller 21 and a timing roller 22. This recording sheet is conveyed by the transfer belt 23 to a transfer position immediately below the photosensitive drum 4. At the transfer position, the toner image on the photosensitive drum 4 is transferred to the recording sheet by the operation of the transfer charger 9. The recording sheet onto which the toner image has been transferred is further conveyed by a transfer belt 23 and a conveyance belt 24, and is discharged to a discharge tray 28 after the fixing device 25 fixes the toner.

FIG. 2 is a schematic structural view of the inside of the printer head 10 as viewed from above. Printer head 10
Is located on the base 17 of the housing.
Light source unit 1 including 2 and collimator lens 13
1, cylindrical lens 14, polygon mirror 15,
The scanning lens group 16 and the like are housed therein. In the above configuration, since the laser beam L emitted from the laser diode 12 is divergent light, it is converted into parallel light by the collimator lens 13, and the cylindrical lens 14
Are condensed in the sub-scanning direction, and are deflected and scanned in the main scanning direction by a polygon mirror 15 rotating at a constant speed in the direction of the arrow by a polygon motor (not shown). Thereafter, the light passes through the scanning lens group 16 and reaches the turning mirror 2 as described above.

FIG. 3 is a perspective view of the light source unit 11. As shown in FIG. 1, the light source unit 11 includes a laser diode 12, a lens barrel 131 in which a collimator lens 13 is provided, and a base 111 for holding these. Here, the lens barrel 131 and the base 111 are formed of a steel material. The base 111 is an L-shaped block when viewed from the side, and includes an LD holding block 113 that holds the laser diode 12 and a lens barrel holding block 112 that holds a lens barrel 131.

The LD holding block 113 has a through hole 1
131 is provided, and the laser diode 12 is fitted into the through hole 1131. The laser beam L emitted from the laser diode 12 and the collimator lens 13
The arrangement is such that the light enters the collimator lens 13 through 131.

One of the lens barrel holding block portions 112 is provided with a V-shaped groove 114 for holding the lens barrel 131 so as to be slidable in the direction of arrow A and in the direction opposite thereto. By sliding the lens barrel 131 along 114, the distance between the collimator lens 13 and the laser diode 12 can be adjusted.

FIG. 4 is an enlarged view of the lens barrel holding block 112 of the base 111. As shown in the figure, the lens barrel holding block portion 112 has a horizontal direction perpendicular to the arrow A direction and a horizontal surface extending between the outer wall surface 115 of the lens barrel holding block portion 112 and the slope 116 of the V-shaped groove 114. Four through-holes 121 to 124 each having a circular cross-sectional shape penetrating between them are provided. Here, each of the through holes 121 to 12
4 are substantially the same in size, and the drilling positions in the vertical direction are also substantially the same. Further, the through holes 121 and 123 and the through holes 122 and 124 are provided at positions facing each other via the V-shaped groove 114.

FIG. 5 is a view when the lens barrel 131 is placed in the V-shaped groove 114 when viewed from the direction of arrow B in FIG. As shown in the figure, the through hole 12 is located at a position where the outer peripheral surface of the lens barrel 131 just contacts the slope 116 of the V-shaped groove 114.
Openings 1211 and 1231 on the V-shaped groove 114 side of 1, 123
Is located, and this is the other through hole 12.
2, 124 have the same configuration.

In such a configuration, the light source unit 1
In the first manufacturing stage, the laser diode 12 is actually driven to emit the laser beam L, and the state of the beam spot formed on a predetermined irradiation surface (for example, the size of the diameter and focusing) is known. Check with a measuring instrument, etc., and move the lens barrel 131 with the arrow A until it is in the specified state.
The distance between the laser diode 12 and the laser diode 12 is adjusted by sliding in a small direction in the direction or the direction opposite thereto (this adjustment is hereinafter referred to as “optical position adjustment”).

Here, a known feed screw mechanism (not shown) or the like can be used as means for sliding the lens barrel 131 in a minute unit in the optical axis direction, but it may be performed manually. When the optical position adjustment is completed, a laser beam for laser welding (hereinafter, simply referred to as “laser beam”) is applied from the outside of the barrel holding block 112 to the outer peripheral surface of the barrel 131 through the through hole 121. Is opening 121
A certain point of a portion which is in contact with the peripheral edge portion 1 is locally irradiated, and the portion is welded (hereinafter, a portion to be welded is represented as a point P in the drawing). This welding process is similarly performed for the other through holes 122 to 124, and the lens barrel 1
31 is fixed to the base 111.

Since the adhesive is fixed by welding, there is no positional variation caused by the contraction and expansion of the solidified adhesive due to environmental changes such as temperature and humidity, and the positional variation caused at the time of screw tightening as in the prior art. Further, since laser welding is performed on an extremely local area having a diameter of less than 1 mm, distortion due to heat generated at the time of heating and melting is extremely unlikely to occur, and the position of the lens barrel 131 (collimator lens 13) is smaller than in the conventional fixing method. Fluctuations can be minimized.

The laser welding can be performed using a known method. Further, the irradiation time and energy amount of the laser beam are welded with such an intensity that the lens barrel 131 can be maintained in a fixed state to the base 111 even under the influence of vibration generated from a drive transmission system or the like during the operation of the printer. As described above, it is determined in advance by an experiment or the like according to the material and size of the lens barrel 131 and the base 111.

The laser light emitted from the single light source is divided into four parts by using an optical waveguide member such as an optical fiber, and each end of the distributed optical fiber is inserted into the through holes 121 to 124. If the laser light is simultaneously irradiated at the position where the fitting is performed and the outer peripheral surface of the lens barrel 131 is exposed, the welding process can be completed in a shorter time.

Here, the number of welding locations is not limited to four.
It may be more than that, or only one place, but it is desirable to weld a plurality of places at the same time. This is because the welding area at each location can be made smaller than when only one location is welded, and distortion due to heat in the welded portion can be reduced. The size of the diameter of the through holes 121 to 124 is not particularly limited as long as laser light can pass therethrough or an optical fiber or the like can be inserted.

In this case, the base 111 is
However, since it is necessary to adjust the position when attaching the base 111 to the base 17, it is desirable that the base 111 be formed integrally with the base 17 by die casting or the like. FIGS. 6A and 6B are diagrams illustrating a configuration example of the light source unit 50 when a base 51 having a different shape from the base 111 is used, wherein FIG. 6A is a plan view and FIG. 6B is a front view.

The main difference from the light source unit 11 is that, as shown in both figures, the portion of the base 51 holding the lens barrel 131 is a concave groove instead of a V-shaped groove. Here, the lens barrel 131 is supported at three positions of the concave groove (two upper end portions on the inner surface of the concave groove and the convex portion 54 provided at the center of the lower surface of the concave groove). The laser light is applied to two points P in a portion where the groove and the inner left upper end portion of the groove are in contact with each other and welded.

The base 51 includes a leaf spring fixing member 52.
A leaf spring 55 is provided for pressing the top of the lens barrel 131 downward through the plate spring. The leaf spring 55 is fixed to the leaf spring fixing member 55 by a screw 56. As a result, free movement of the lens barrel 131 is restricted, and if the printer head 10 is moved to a place for laser welding after the optical position adjustment is performed, the vibration caused by the movement causes Even if it is propagated to 51,
The adjustment position does not fluctuate easily, laser welding can be performed while maintaining the adjustment state, and the pressing force acts as it is even after welding, so that the lens barrel 13 can be used.
1 can be prevented from changing.

Next, FIG. 7 is a view showing an example of a configuration in a case where the lens barrel 131 is fixed in a state of being inserted into the cylindrical base 61. As shown in FIG.
Have substantially the same outer diameter, and when the lens barrel 131 is inserted into the base 61, the inner peripheral surface of the base 61 and the outer peripheral surface of the lens barrel 131 come into close contact with each other, so that there is a play in the radial direction. There is no sticking. Then, the lens barrel 131 is moved in the direction of arrow C or in the opposite direction (axial direction) to adjust the optical position, and then the laser beam is passed through the through-hole 61 formed in the base 61.
One point P of the contact portion between the base 61 and the lens barrel 131 through
Is locally irradiated with laser welding.

FIG. 8A is a cross-sectional view showing a configuration example in which the lens barrel 131 is fixed in a state where a lens barrel 131 having a smaller diameter is inserted into the cylindrical base 62. .
In this case, after the optical position adjustment is performed, the base 62
A laser beam is applied to a point P at a contact portion between the base 62 and the lens barrel 131 through a through hole 621 formed in the lowermost portion of the base member to perform laser welding. In this example, only the contact portion between the inner peripheral surface of the base 62 and the outer peripheral surface of the lens barrel 131 is fixed. May occur. Therefore, it is desirable to provide a plurality of welding points in the axial direction and firmly fix them so as not to cause such deflection.
Also in this case, it is desired that welding to each part be performed simultaneously, as described above.

FIG. 8 (b) is a cross-sectional view showing an example of a configuration in the case where the base 66 is formed of a steel plate. As shown in the figure, a through hole 67 is formed in a portion of the base 66 that comes into contact with the lens barrel 131, and a laser beam is irradiated to one point P of the contact portion via the through hole 67. Thereby, the part is welded. If the base 66 is formed of a steel plate in this way,
The weight of the light source unit itself can be reduced, and the weight can be reduced. Also in this case, if the tip of the optical fiber is guided to the position facing the through hole 67 using an optical fiber or the like, laser welding can be easily performed simultaneously at two places.

FIG. 9 is a perspective view showing a configuration example in which an auxiliary member 75 is used to fix the lens barrel 131 to the base 71. In this example, a steel belt-shaped member is used as the auxiliary member 75, and both ends 76 of the member are connected to the upper surface 72 of the base 71.
The lens barrel 131 is fixed by laser welding one or more points of the contact portion. According to such a configuration, even if the lens barrel 131 is made of a material other than metal, for example, a resinous one, the above-described effect that the position fluctuation of the lens barrel 131 can be suppressed as much as possible can be enjoyed.

The holding frame for holding the collimator lens 13 is not limited to a cylindrical one such as the above-mentioned lens barrel, but may be a member having any other shape. FIG. 10 (a)
FIG. 7 is a perspective view showing an example in which a collimator lens 83 is inserted into a hole 82 provided in a plate-like holding frame 81 to integrally form the two. Here, the shape of the V-shaped portion 84 of the holding frame 81 matches the shape of the V-shaped groove 114 of the base 111, whereby the holding frame 81 is placed in the V-shaped groove 114. In this state, it can be fixed to the base 111 by laser welding.

FIG. 10B is a perspective view showing an example in which the collimator lens 85 is fitted into a groove 87 provided in a semicircular holding frame 86 to integrally form the two. If the collimator lens 85 can be reliably held, it is not always necessary to hold the entire circumference of the lens.
A simple configuration as shown in FIG.

(Attachment Structure of Base to Base) Next, an attachment structure when the base is fixed to the base of the laser beam scanning device will be described. FIGS. 11A and 11B are views showing the configuration of the light source unit 150 here, wherein FIG. 11A is a plan view and FIG. 11B is a side view.

As shown in both figures, this light source unit 15
Reference numeral 0 denotes a structure in which the laser diode 12 and a lens barrel 131 having a collimator lens (not shown) are attached to a base 151, similarly to the light source unit 11. The base 151 is provided with three legs 152 serving as attachment portions to the base 17, and a through hole 153 is formed in each leg 152 in a vertical direction. On the surface of the base 17, projections 171 having a diameter larger than that of the through hole 153 are provided at positions where the projections 171 abut on the legs 152.

In such a configuration, at the time of manufacturing, each leg 152 is placed on each projection 171 and the laser diode 12 is actually driven to emit the laser beam L. Then, the state of the beam spot formed on the surface of the photosensitive drum 4 or on the predetermined irradiated surface is confirmed by the same method as described above, and the position of the base 151 is adjusted until the beam spot reaches the predetermined state. Done. After the position adjustment is completed,
0 (b), the opening of the through hole 153 and the projection 171 are formed.
The laser light is irradiated from above onto a point P in a portion where the contact is made, and the portion is welded. Also here, since the welding is performed only in the local range as described above, there is no danger that the position of the base 151 is lowered by melting as the height of the top of the projection 171 changes during welding. In addition, distortion due to heat at the time of welding can be suppressed to a very small value, and positional fluctuation can be suppressed to be extremely small as compared with the conventional method of simply fixing by screwing or bonding.

Also, since the top of the projection 171 and the surface of the leg 152 come into contact with each other in a state close to a point, the leg 1
In the conventional configuration in which a seating surface that makes surface contact with 52 is provided on the base 17 and both surfaces are brought into contact with each other and fixed by screwing, if any of the surfaces of the members is slightly inclined, it is forcibly fixed. This does not cause a problem that the seating surface is deformed and the position of the base 151 itself is shifted from the adjustment position, and the adjusted state is easily maintained.

FIG. 12 is a sectional view showing an example in which a bottomed circular hole 154 is provided without providing a through hole 153 in the leg 152. In this example, a laser beam is applied to the bottom surface 155 of the bottomed circular hole 154 from above, and a part of the bottom surface 155 is melted, so that the leg portion 152 and the projection 171 of the base 17 are laser-welded. Since the welding can be performed by irradiating the laser beam to the substantially center position of the bottom surface 155 of the bottomed circular hole 154, the adjustment of the irradiation position of the laser light is easier than the above-described configuration in which the laser light is irradiated to a certain point. Become.

Further, the light source unit may be configured as shown in FIG. FIGS. 13A and 13B are diagrams illustrating a configuration example when the light source unit is fixed on the base 17 provided with the positioning pins 172, wherein FIG. 13A is a plan view and FIG. 13B is a side view. As shown in both figures, the positioning pin 172 is for restricting the horizontal movement of the base 151, and in this example, the tip of the positioning pin 172 fits into a hole 156 provided in the base 151. In the inserted state, the vertical position of the base 151 is adjusted.
The leg 152 of the 51 and the projection 171 of the base 17 are laser-welded.

Thus, when the position of the base 151 is adjusted, only the vertical direction needs to be adjusted, and the adjustment process becomes simpler than the case where the adjustment in the horizontal direction is also performed. FIG. 14 shows a case where a recess 158 is provided on the base 17 side of the leg 157 instead of the positioning pin 172, and
FIG. 7 is a diagram showing a configuration example in a case where a convex portion 173 that fits with the concave portion 158 is provided on 7 and positioning is performed by fitting the convex portion 173 and the concave portion 158.

As in the case of the positioning pin, the position in the horizontal direction is regulated, so that there is an effect that only the position adjustment in the vertical direction is required. Further, since the leg portion 157 also has a positioning function, it is not necessary to newly provide a positioning pin, and the configuration of the base 17 is correspondingly simplified. Note that a protrusion 174 is provided on the upper portion of the protrusion 173, and the protrusion 17 is fitted with the protrusion 173 and the recess 158.
The top of 4 is in contact with the inner surface of the recess 158 in a state close to a point. Then, in a state where the optical position has been adjusted, the point P at the contact portion between the top of the projection 174 and the through hole 153 is irradiated with laser light, and the two are fixed by laser welding.

FIG. 15 shows a case where both the leg 152 and the base 17 shown in FIG. 11 are made of a material other than metal, for example, a resin. FIG. 10 is a diagram showing an example in the case where metal members 159 and 175 are inserted in FIG. If the metallic member is arranged at the welding location in this way, the base 151
The material of the base 17 and the base 17 is not limited to metal, and for example, a resin such as ABS (acrylonitrile, butadiene, styrene) or PC (polycarbonate) can be used. In particular, if a resin is used as a material, it is extremely easy to integrally form the base and the base.

(Specification of Position of Fixing Barrel to Base) In the above-mentioned "mounting structure of barrel", the barrel is fixed to the base using laser welding, so that positional fluctuation of the barrel is suppressed as much as possible. However, by specifying the position where the lens barrel is fixed to the base, positional fluctuation can be suppressed. FIG. 16 (a)
It is a perspective view of the light source unit 200, (b) is a top view. 17 and 18 are cross-sectional views of the light source unit 200 shown in FIG. 16B taken along lines DD and EE, respectively. The light source unit 200 includes a base 201 as in the light source unit 11.
And a lens barrel 202, a collimator lens 203, and a laser diode 204.

As shown in FIG. 16A, the base 201
Is an L-shaped block when viewed from the side, and has an LD holding block 2011 that holds the laser diode 204 and a lens barrel holding block 2012 that holds the lens barrel 202 to which the collimator lens 203 is attached. The lens barrel holding block portion 2012 is provided with a concave groove for holding the lens barrel 202 so as to be slidable in the axial direction. By sliding the lens barrel 202 with the lens barrel 202 fitted therein, an optical communication with the laser diode 204 is achieved. The position can be adjusted.

As shown in FIG. 18, the diameter of the collimator lens 203 is substantially the same as the diameter of the lens barrel 202, and the mounting seat surface 2031 provided on the lens 203 is
02 (upstream in the traveling direction of the laser beam L) end surface 2
021. Here, the mounting seat surface 2031
Is a plane orthogonal to the optical axis of the collimator lens 203, and is provided on a plane including a principal point indicated by a point S in the figure (hereinafter, this plane is referred to as a "principal plane").

In such a configuration, at the time of manufacture, the lens barrel 202 is mounted on the base 201 and the laser diode 2 is mounted.
After the optical position adjustment with respect to the end surface 2021, the outer peripheral surface of the lens barrel 202 is in contact with the base 201.
Two nearby points (point P in the figure) are irradiated with laser light, and both are fixed by laser welding. In this way, by setting the position where the lens barrel 202 is fixed to the base 201 in the optical axis direction near the mounting seat surface 2031 of the collimator lens 203, for example, the lens barrel 202 expands and contracts in the optical axis direction due to a temperature change. Also, since the collimator lens 203 expands and contracts with the fixed position as the reference position, the displacement of the collimator lens 203 itself in the optical axis direction can be reduced. Then, the collimator lens 20
When the lens 3 itself expands and contracts in the optical axis direction with a change in temperature, it expands and contracts with reference to the mounting seat surface 2031 serving as a mounting surface for the lens barrel 202. Here, the mounting seat surface 2031 is used.
Is provided at a position on the main plane.
Compared with the case where the lens is fixed to the lens barrel 202 at a position away from the position 31, the position fluctuation of the principal point which is the optical center can be suppressed as small as possible. As a result, a change in the focal position can be suppressed to a small degree, a change in the optical positional relationship with the laser diode 204 can be reduced, and the optically adjusted state can be maintained as much as possible.

In the above description, the lens barrel 2 is formed by laser welding.
02 is fixed to the base 201, but the fixing means is not limited to this. The above-described effect can be obtained by fixing at a position near the main plane, so that other fixing means such as soldering or bonding with an adhesive can be used as long as the strength can be secured. When the adhesive is used, the above-described problem occurs. However, since the positional fluctuation can be suppressed as compared with the case where the adhesive is bonded at another position, a certain effect can be obtained.

In the case of bonding, instead of fixing the lens barrel 202 to the base 201, the collimator lens 2
It is also possible to directly fix a portion corresponding to a position on the main plane, which is a contact portion between the substrate 03 and the base 201. Further, here, the collimator lens 203 is configured to be attached to the end surface of the lens barrel 202, and thereby the boundary between the mounting seat surface 2031 and the lens barrel 202 can be visually observed.
The fixing position of the lens barrel 202 (that is, the position near the mounting seat surface 2031) is clear, and the fixing work at the time of manufacturing can be easily performed. If the position of the mounting seat surface of the collimator lens cannot be visually recognized because the collimator lens is provided inside the lens barrel, it is necessary to take measures such as marking the position on the outer peripheral surface of the lens barrel.

The position of the principal point can be determined by a known method from the polarities and refractive indexes of the lenses. FIG.
FIG. 7A is a diagram illustrating a configuration example of a light source unit 207 when a collimator lens 205 having a different shape from the above-described collimator lens 203 is used.
FIG. 5B is a cross-sectional view of the light source unit 207, and FIG. The members other than the collimator lens 205 are the same as those of the light source unit 200.

As shown in both figures, the collimator lens 205 of the present example has a shape in which both sides are raised in a mountain shape, and has a mounting seat surface 2051 on the main plane as described above. The mounting seat surface 2051 is attached to the right end surface (downstream side in the traveling direction of the laser beam L) 2022 of the lens barrel 202. Then, the optical position adjustment is performed, and after the adjustment is completed, a laser beam is applied to a position (point P) near the end surface 2022 at a contact portion of the outer peripheral surface of the lens barrel 202 with the base 201. Laser welded.

FIGS. 20A and 20B are cross-sectional views showing an example of a collimator lens having still another shape. As shown in both figures, the mounting seat surfaces 2091 and 2101 of the respective collimator lenses 209 and 210 are provided on the main plane in the same manner as described above, and the mounting seat surface 2091 is provided on the left end surface 2021 of the lens barrel 202. The mounting seat surface 2101 is configured to be attached to the right end surface 2022 of the lens barrel 202, respectively.

It should be noted that the light source unit is not limited to the configuration described above, but may be configured as shown in FIGS. FIG. 21 shows that a flange 224 is provided at one end.
And the collimator lens 22 is provided on the flange portion 224.
6A and 6B are diagrams illustrating a configuration example of a light source unit 220 using a lens barrel 225 in which a base 6 is provided, wherein FIG. 7A is a plan view, and FIG. 7B is a diagram illustrating only the base 221 illustrated in FIG. FIG. 4 is a cross-sectional view taken along an arrow when cut, and a side view of a lens barrel 225 is also added for convenience of description.

As shown in both figures, the lens barrel 225 is configured such that the surface 2241 of the flange portion 224 is located on the main plane with the collimator lens 226 provided inside. Is a mounting seat surface with the base 221. On the other hand, the base 221 has a cylindrical portion 223 of the lens barrel 225.
Is provided.

In such a configuration, at the time of manufacture, the cylindrical portion 223 is fitted into the concave groove 227, and the surface 2241 of the flange portion 224 is brought into contact with the surface 222 of the base 221. P is irradiated with laser light and laser-welded. FIGS. 22A and 22B are diagrams illustrating a configuration example of the light source unit 230 when a collimator lens 233 having another shape is provided in the lens barrel 232, where FIG. 22A is a plan view and FIG. The light source unit 230 shown in FIG.
It is arrow sectional drawing at the time of cutting by a line.

As shown in both figures, the lens barrel 232 has an end surface 232 with the collimator lens 233 provided therein.
1 is located on the main plane, and the end surface 2321 serves as a mounting seat surface with the base 231. In such a configuration, at the time of manufacturing, the lens barrel 232 is
Is fitted into a concave groove 2311 provided at the end face 2321.
Is brought into contact with the base 231, laser light is applied to two portions P of the contact portion, and laser welding is performed.

During manufacturing, for example, when it is necessary to move the light source unit whose optical position has been adjusted to the place where laser welding is performed, the position of the adjusted lens barrel fluctuates due to vibration during the movement. In such a case, there is no point in adjusting the optical position. Therefore, it is desirable to provide a support means for supporting the lens barrel so that the adjusted state does not easily change due to vibration or the like. Hereinafter, the configuration example is shown in FIG.
27 will be described with reference to FIG.

FIGS. 23A and 23B are diagrams showing an example of the configuration of a light source unit 240 utilizing the urging force of a leaf spring 241 as a support means, wherein FIG. 23A is a plan view, and FIG. 23B is a light source unit shown in FIG. FIG. 240 is a side view when 240 is viewed from the direction of arrow H. Here, the light source unit 240 is configured by adding a leaf spring 241 and a leaf spring fixing member 242 for fixing the same to the light source unit 200 shown in FIG. 16, and the other members are the same. Is used.

As shown in both figures, the leaf spring fixing member 242
Is fixed to the upper surface of the base 201, and one end of the leaf spring 241 is fixed to the leaf spring fixing member 242 with a screw 243. The other end of the leaf spring 241 is at the top of the lens barrel 202 and is in contact with a substantially central position in the longitudinal direction from above. The lens barrel 202 is pressed downward by the urging force of the leaf spring 241. Then, optical position adjustment is performed in this state. By doing so, after the optical position adjustment is performed, the position does not easily fluctuate due to vibration during movement or the like. Here, leaf spring 2
It is desirable that the contact position of the lens 41 with the lens barrel 202 is the position shown in FIG. For example, when only one end of the lens barrel 202 is pressed, little pressure is applied to the other end and stability is impaired.

FIG. 24 shows a linear spring 2 instead of a leaf spring.
It is a figure which shows the example of a structure of the light source unit 250 using 53, (a) is a top view of the light source unit 250, (b) is a side view when the light source unit 250 of (a) is seen from the arrow H direction. It is. Here, similarly to the light source unit 240, the light source unit 250 is configured by adding a linear spring 253 to the light source unit 200 and a supporting portion 251 for supporting the same.

As shown in both figures, the supporting portions 251 are provided on the upper surface of the base 201 at positions opposed to each other with the lens barrel 202 interposed therebetween, and the pins 252 set up on the respective supporting portions 251 are provided. Is engaged with a linear spring 253. Then, in this state, the spring 253 comes into contact with the top of the lens barrel 202 from above, and the lens barrel 202 is pressed downward by the urging force.

Further, a configuration as shown in FIGS. 25 to 27 can be adopted. FIG. 25 shows a light source unit 260 using a plunger 262 having a configuration in which the tip can be advanced and retracted by the biasing force of an internally provided spring instead of a leaf spring.
3A is a diagram showing a configuration example of FIG.
FIG. 60B is a plan view of the light source unit 2 shown in FIG.
60 is a sectional view taken along line JJ of FIG.
FIG. 4 is a cross-sectional view showing a configuration of a plunger 262.

As shown in FIGS. 25A and 25B, the light source unit 260 has a plunger 262 in the light source unit 200 and a U-shaped cross section.
1 and a fixing member 261 for holding the plunger 262 fixed thereto.
Then, as shown in FIG.
Is composed of a screw portion 2621 and a head portion 2622. The screw portion 2621 has a cylindrical shape, a thread is cut on the outer peripheral surface, and a spring 263 and a ball 264 are provided inside. The distal end portion 2623 of the screw portion 2621 is tapered, and the diameter of the opening of the distal end portion 2623 is smaller than the diameter of the central portion of the screw portion 2621. Since the diameter of the ball 264 is slightly larger than the opening of the distal end portion 2623, the ball 264 urged in the direction of the distal end portion 2623 by the spring 263 is partially exposed from the opening of the distal end portion 2623. Is maintained in.

The fixing member 261 has the plunger 26
A screw hole 2611 for screwing the plunger 2 is provided, and the plunger 262 is tightened until the ball 264 exposed from the distal end portion 2623 of the plunger 262 hits the outer peripheral surface of the lens barrel 202 and recedes slightly inward. As a result, the pressing force of the spring 263 is increased by the ball 264.
Through the lens barrel 202, the lens barrel 202 is pressed downward, and the lens barrel 202 is supported.

FIG. 26 shows a pawl member 27 instead of a leaf spring.
2A and 2B are diagrams illustrating a configuration example of a light source unit 270 that supports the lens barrel 202 by using the light source unit 270. FIG.
(B) is a light source unit 270 of FIG.
It is arrow sectional drawing at the time of cutting | disconnection by the K line. As shown in both figures, the light source unit 270 is
The configuration is almost the same as that of 00, except that the base 271 is formed of resin and the claw members 272 are integrally formed at opposing positions of the base 271 with the lens barrel 202 interposed therebetween.

The lens barrel 202 is pressed against the base 271 from above by the urging force of the claw member 272, and after the optical position is adjusted in this state,
It is fixed to the base 271. Here, the base 271 is used.
Is made of resin, it is fixed at point P by bonding or welding with an adhesive. The use of an adhesive causes expansion and contraction due to temperature change. However, in this example, the bonding portion is limited to a local range, and thus even if expanded or contracted, the extent can be suppressed to an extremely small range. Although it is conceivable that the bonding strength is reduced by making the bonding portion local, the lens barrel 202 is supported by the claw member 272 even after bonding, so that no problem occurs.

FIG. 27 shows a case where a cylindrical lens barrel holding block 282 is provided on an L-shaped base 281 in side view, and a lens barrel 284 is provided.
FIGS. 7A and 7B are diagrams illustrating a configuration example in which the lens barrel 284 is supported by being inserted into a lens barrel holding block portion 282, where FIG. 7A is a perspective view and FIG. As shown in both figures, the lens barrel 284 has a flange portion 285, and the collimator lens 283 is provided inside the flange portion 285. The surface 286 of the flange portion 285 is located on the main plane of the collimator lens 283, and serves as an attachment surface to the end surface 287 of the lens barrel holding block portion 282. Lens barrel 28
The outer diameter of the lens barrel 4 is almost the same as the inner diameter of the lens barrel holding block 282. Therefore, when the lens barrel 284 is inserted into the lens barrel holding block 282, the outer peripheral surface of the lens barrel 284 is Will be in close contact with the inner peripheral surface. As a result, the lens barrel 284 is supported by the lens barrel holding block 282 without rattling in the radial direction, and can be fixed by laser welding in that state.

(Mounting Structure of Laser Diode on Printed Circuit Board) Next, a description will be given of a mounting structure of a laser diode on a printed circuit board in comparison with a conventional example. FIG. 28 (a)
Is a cross-sectional view showing an example of a mounting structure of the laser diode 301 in the present embodiment.

As shown in FIG.
1 is a laser chip 302 of a light emitting element on a stem 303.
And a cap (not shown) for preventing the laser chip 302 from contacting the outside air is attached. An end of a lead 304 for supplying a drive current to the laser chip 302 is connected to a printed circuit board 305. The solder 307 is attached to a pattern (not shown) provided on the back side of the. Here, the laser diode 301 is fixed on the printed board 305 by soldering the bottom surface of the stem 303 to the printed board 305.

FIG. 28 (b) shows a portion where the stem 303 is soldered to the printed circuit board 305 by M-
It is an arrow sectional view at the time of cutting by the M line. As shown in the figure, the solder 307 is poured only into the periphery of the stem 303 in order to prevent a short circuit between the leads 304 due to the solder 307.

FIG. 29 is a sectional view showing a conventional laser diode mounting structure. As shown in the figure, in this example, a holder 310 for holding a stem 303 of a laser diode 301 is provided on a printed circuit board 305, and the stem 303 is attached to the holder 310 with an adhesive 311.
It is glued. In this conventional configuration, the solidified adhesive contracts and expands due to environmental changes such as temperature and humidity, and the position of the laser diode 301 may fluctuate. As a fixing method other than the bonding, there is a method of fixing the stem 303 by press-fitting the holder 310. However, at the time of press-fitting, residual distortion occurs in the stem 303, causing a positional change.
Due to the difference in the coefficient of linear expansion due to the difference in the material of the holder 310 and the material of the printed board 305, when the temperature and humidity change, a difference occurs in the amount of deformation between the two, and the distortion may cause a positional change.

On the other hand, in the structure of the present embodiment, as described above, the stem 303 is directly fixed by the solder 307 at a position close to the printed circuit board 305 so that the two are united. Since shrinkage and the like due to temperature fluctuations are extremely small as compared with the adhesive, position fluctuations can be suppressed as compared with the conventional case, and the state where the optical position has been adjusted can be stably maintained.

In order to perform the soldering, it is necessary to arrange a metal member such as a copper foil on the portion of the printed circuit board 305 to be soldered. In addition, each lead 304
Is not required to be in a short circuit state.
If the peripheral surface of 04 is insulated, the solder 307 can be poured into the entire back surface of the stem 303, and the fixing strength can be further increased.

Also, when the printed circuit board 305 is fixed to the base of the light source device, it is desirable to perform direct soldering as described above. This is because screwing or bonding may cause a change in the mounting position due to an environmental change or the like. FIG.
FIG. 4 is a cross-sectional view illustrating a configuration example when a laser diode 301 is fixed to a printed circuit board 305 via a steel plate 321.

As shown in the figure, in this example, the stem 30
3 is in contact with the steel plate 321 and the contact portion 2
The spot P is locally irradiated with a laser beam, and laser welding is performed. Thus, the resin printed circuit board 30
The laser diode 30 is attached to the steel plate 321 having a strength higher than 5.
By directly fixing 1, even if the printed circuit board 305 is flexed, it is hardly affected by the flexure, and the positional fluctuation can be further reduced.

Since the steel plate 321 is provided with a through hole 322 for guiding each lead 304 to the printed circuit board 305 without making contact with the steel plate 321, each lead 304 is connected via the steel plate 321. There is no short circuit. Further, since the pattern surface of the printed circuit board 305 is provided only on the surface opposite to the contact surface of the steel plate 321 (the right surface in the drawing), the pattern surface and the steel plate 321 are kept in an insulated state. The steel plate 321 is fixed to a base of the light source device.

(Mounting structure of laser diode to base)
Next, a mounting structure for fixing the laser diode to the base will be described. FIG. 31A is a front view showing the configuration of the light source unit 500 here. The light source unit 500 is similar to the light source unit 11 in the base 5.
01, a laser diode 506, a collimator lens 504, and a lens barrel 505.

FIG. 31 (b) is a side view of the light source unit 500 shown in FIG. 31 (a) when viewed from the direction of arrow N, and a part thereof is omitted for convenience of explanation. As shown in both figures, the collimator lens 504 is attached to the lens barrel 505, and the base 501 is in a state where the optical position can be adjusted.
Is held on. The base 501 is provided with an LD insertion hole 502 for holding a laser diode 506, and the diameter of the LD insertion hole 502 is substantially the same as the diameter of the stem 507 of the laser diode 506.
The leads 508 of the laser diode 506 are fixed to a printed board (not shown).

In such a configuration, at the time of manufacturing, first, the stem 507 of the laser diode 506 is inserted into the LD insertion hole 502. Then, laser light is locally applied to two points P at a contact portion between the opening 503 of the LD insertion hole 502 and the stem 507 and is laser-welded and fixed to the base 501. By fixing the laser diode 506 to the base 501 by laser welding in this way, when the adhesive is poured between the LD insertion hole 502 and the stem 507 and bonded, expansion of the solidified adhesive due to temperature and humidity fluctuations, etc. Therefore, the conventional problem that the position of the laser diode 506 fluctuates or the position of the laser diode 506 fluctuates due to residual distortion generated when the stem 507 is pressed into the LD insertion hole 502 or the like is eliminated, and optical position adjustment is performed. State can be maintained stably.

When laser welding is performed, residual distortion due to heat is generated. However, since the welding location is in an extremely local range, for example, in a range in which the diameter is less than 1 mm as described above, there is no The heat is hardly conducted to the inside, and the influence thereof is extremely small. In the above description, the number of welding points is two, but the number of welding points may be three as shown in FIG. The number of welding points is not particularly limited, but when welding a plurality of locations, it is desirable to weld at substantially equal intervals on the circumference of the stem 507. This is because if an extremely deviated portion is welded, the unwelded portion becomes a free end and becomes unstable. As in the above, it is desirable to simultaneously weld portions to be welded using an optical fiber or the like. This is because the welding time can be reduced.

FIG. 33 is a perspective view showing an example of the configuration of a light source unit in which a cylindrical LD holding section 511 is provided on a base 501, and a laser diode 506 is held in the LD holding section 511. As shown in FIG.
1 has three protrusions 512 of substantially the same size.
Are provided at equidistant intervals in the circumferential direction, and when the laser diode 506 is inserted into the LD holding portion 511, the tip of each projection 512 just contacts the outer peripheral surface of the stem 507. The LD holding unit 511 includes:
A through-hole 513 is formed in a vertical direction at a position just beside the protrusion 512 located at the top of the three protrusions 512.

In such a configuration, at the time of manufacturing, as shown in the figure, the stem 507 is gripped by claws 530 such as a robot arm, and the laser diode 506 is inserted into the LD holding section 511. FIG. 34 shows a state where the laser diode 506 is inserted into the LD holding section 511. FIG.
35 is a side view when viewed from the arrow Q direction of FIG.
34 is a cross-sectional view of the LD holding unit 511 shown in FIG. 34 taken along the line RR.

As shown in FIG. 34, the claw 530 enters the gap between the inner peripheral surface of the LD holding portion 511 and the outer peripheral surface of the stem 507, and moves the claw 530 up and down, left and right, and back and forth. Alternatively, the position of the laser diode 506 is adjusted by rotating it. Here, the laser diode 506 is actually driven to form an image of the laser beam L transmitted through the collimator lens 504 (FIG. 31) on a predetermined surface to be illuminated. The laser diode 506 is moved or rotated in minute units until the direction is changed, and its direction, the distance from the collimator lens 504, and the like are adjusted.

When the adjustment is completed, the claw 530 is stopped to maintain the state, and as shown in FIG.
Laser welding is performed by irradiating a laser beam to a point P at a contact portion between the projection 512 and the stem 507 through a through hole 513 formed in the LD holding portion 511 to fix the laser diode 506. In this example, laser welding is performed for 1
Although the process is performed on only one protrusion 512, the process may be performed on two or all protrusions 512 in order to further increase the fixing strength.

The means for gripping the laser diode 506 is not limited to the robot arm claw 530 as described above. For example, the bottom surface of the stem 507 is sucked and held using a suction means such as a pump, and the suction means is moved in this state to move the laser diode 506 to the LD holding unit 5.
11 to adjust the position.
Of course, the position may be adjusted manually.

Further, the LD holding portion 511 can be shaped as shown in FIG. FIG. 36A shows FIG.
FIG. 14 is a cross-sectional view showing an example in which a concave portion 514 is provided instead of the through hole 513 shown in FIG. In this example, the bottom surface of the concave portion 514 is irradiated with laser light, a part of the bottom surface is melted, and the melted portion comes into contact with the stem 507 so that the stem 507 is fixed to the LD holding portion 511. .

Also, instead of the concave portion 514, FIG.
A step 515 is provided as shown in FIG.
By providing a tapered portion 516 as shown in (c) and irradiating a laser beam from above to the step portion 515 and the portion where the wall pressure of the tapered portion 516 is reduced, the stem 507 is applied to the LD holding portion 511 by laser. It can be fixed by welding. Since the welding can be performed by irradiating the surface of the thin portion such as the step portion 515, the adjustment of the irradiation position of the laser light is simplified as compared with the case of irradiating the laser light only at one point P as described above.

The present invention can be applied not only to the light source unit having the above configuration but also to a light source unit having a configuration as shown in FIGS. FIG. 37 shows a cylindrical base 6.
01 is a cross-sectional view showing an example of a light source unit in which a laser diode 602 is inserted into one side and a lens barrel 605 holding a collimator lens 604 is inserted into the other side, and these members are integrally formed.

Here, the laser diode 602 is fixed to the base 601 by laser welding two points P in the contact portion between the stem 603 and the base 601. By thus integrally configuring these members,
The number of parts can be reduced as compared with the conventional case, so that the cost can be reduced and the space can be saved. In this example, it is desirable that the lens barrel 605 is also laser-welded to the base 601.

FIG. 38 shows an example in which the number of parts is further reduced, and the collimator lens 606 is directly attached to the base 601. FIG. 39 is a cross-sectional view showing a configuration example of a light source unit in a so-called multi-beam type laser beam scanning apparatus that simultaneously exposes and scans a photosensitive drum using two laser beams.

The light source unit includes a base 607, a collimator lens 608, laser diodes 609 and 610.
The laser beam L1 emitted from the laser diode 609 is deflected in the direction of the collimator lens 608, and the laser beam L2 emitted from the laser diode 610 is transmitted as it is to form the collimator lens 608.
And a beam combiner 612 composed of a beam splitter in which two prisms are bonded to each other.

The base 607 includes LD holding blocks 6071 and 6072 for holding the two laser diodes 609 and 610. Each of the laser diodes 609 and 610 has an LD holding block 6071 and 6107.
The laser welding is performed at each of two points P in the contact portions with the laser diodes 609 and 072.
610 is fixed to the base 607.

As described above, also in this embodiment, since the members constituting the light source unit are integrally attached, the number of parts is minimized, and the same effect as described above can be obtained. It is needless to say that the present invention is not limited to the above embodiment, and the following modified examples can be considered. (1) In the above embodiment, the present invention is applied to the case where the laser diode and the collimator lens are fixed to the base. However, another optical element such as a cylindrical lens is arranged on the base of the laser beam scanning device or on the base. The present invention can also be applied to the case where the optical element is fixed to the base for the optical element.

(2) In the above embodiment, the example in which the light source device and the light beam scanning device according to the present invention are applied to the laser beam scanning device of the printer has been described. However, the present invention is applied to an image forming apparatus such as a copying machine. The present invention is applicable to laser beam scanning devices in general. Further, the present invention is not limited to the scanning device, and can also be applied to a light source device which is required to irradiate a predetermined position on an object with a light beam emitted from a light emitting element such as a laser diode via an optical element such as a collimator lens. .

[0097]

As described above, according to the present invention, there is provided a light source device for irradiating an object with a light beam emitted from a light emitting element via an optical element, and a holding frame for holding the optical element. However, since the light-emitting element and the optical position are adjusted, it is fixed to the base of the light source device by laser welding. Laser beam scanning for exposing the light source device to a photosensitive drum in an image forming apparatus such as a copying machine can be performed by reducing position fluctuations and forming an image of a light beam on an object in an appropriate state. When used as a light source device of the apparatus, it is possible to reduce the fluctuation of the exposure scanning position of the laser beam on the photosensitive drum, and to improve the image quality.

Further, since the mounting portion of the optical element is provided in a plane orthogonal to the optical axis of the optical element and including the position of the principal point of the optical element or in a plane close to the plane, Even if the optical element contracts and expands due to a temperature change, it contracts and expands based on the mounting portion, so that the fluctuation of the position of the principal point, which is the optical center, can be small, and the fluctuation of the optical distance from the light emitting element. Laser beam scanning device for exposing the light source device to a photosensitive drum in an image forming apparatus such as a copying machine by exposing the light beam to an irradiation target in an appropriate state. When the light source device is used as the light source device, the fluctuation of the exposure scanning position of the laser beam on the photosensitive drum can be reduced, and the image quality can be improved.

A light source device comprising a light emitting element mounted on a stem and a circuit board for supplying a drive current to the light emitting element, wherein the bottom surface of the stem is directly soldered to the circuit board or Since it is fixed by laser welding, a holding member for holding the stem is provided on the circuit board as in the related art, and when the stem is bonded to the holding member with an adhesive, the solidified adhesive is removed. The problem that the position of the light emitting element changes due to expansion and contraction due to temperature change can be prevented, and the light source device is
For example, when it is used as a light source device of a laser beam scanning device for exposing and scanning a photosensitive drum in an image forming apparatus such as a copying machine, a variation in an exposure scanning position of a laser beam on the photosensitive drum can be reduced, and image quality can be reduced. Can be improved.

A light source device comprising a light emitting element mounted on a stem and a holding member for holding the stem, wherein the stem is provided with a laser beam on the holding member in an optically adjusted state. Since the stem is fixed by welding, when the stem is adhered to the holding member for holding the light emitting element with an adhesive as in the related art, the solidified adhesive expands due to a temperature change and the position of the light emitting element fluctuates. The light source device can be prevented.
For example, when it is used as a light source device of a laser beam scanning device for exposing and scanning a photosensitive drum in an image forming apparatus such as a copying machine, a variation in an exposure scanning position of a laser beam on the photosensitive drum can be reduced, and image quality can be reduced. Can be improved.

Further, a light source unit including a light emitting element, a collimator for collimating a light beam emitted from the light emitting element, and a deflector for deflecting the light beam from the light source unit to scan the object to be scanned. In the light beam scanning device, the light source unit is fixed to the base portion of the light beam scanning device by laser welding. The problem that the position of the light source unit fluctuates due to rotation torque applied to the light source unit at the time of scanning can be prevented, and the light beam scanning device can be used for exposing and scanning a photosensitive drum in an image forming apparatus such as a copying machine. When used as a laser beam scanning device, fluctuations in the exposure scanning position of the laser beam on the photosensitive drum can be reduced. , So that thereby improving the image quality.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a schematic configuration of an entire printer.

FIG. 2 is a schematic configuration diagram of the inside of a printer head of the printer as viewed from above.

FIG. 3 is a perspective view of a light source unit in the print head.

FIG. 4 is an enlarged view of a lens barrel holding block of a base of the light source unit.

5 is a view when the lens barrel is placed in a V-shaped groove of the lens barrel holding block when viewed from the direction of arrow B in FIG. 4;

6A and 6B are diagrams showing another configuration example of the light source unit, wherein FIG. 6A is a plan view and FIG. 6B is a front view.

FIG. 7 is a diagram showing a configuration example in a case where a lens barrel is fixed in a state of being inserted into a cylindrical base.

FIG. 8A is a cross-sectional view showing a configuration example when a lens barrel having a smaller diameter is inserted into a cylindrical base and the lens barrel is fixed, and FIG. FIG. 4 is a cross-sectional view showing a configuration example when a base is formed of a steel plate.

FIG. 9 is a perspective view showing a configuration example when an auxiliary member is used to fix the lens barrel to the base.

FIG. 10A is a perspective view showing an example in which a collimator lens is inserted into a hole provided in a plate-like holding frame to integrally form the two, and FIG. FIG. 9 is a perspective view showing an example in which a collimator lens is fitted into a groove provided in a semicircular holding frame to form an integral unit.

11A and 11B are diagrams illustrating a configuration example of a light source unit different from the above, where FIG. 11A is a plan view and FIG. 11B is a side view.

12 is a cross-sectional view showing an example in which a bottomed circular hole is provided in a leg of the light source unit shown in FIG.

13A and 13B are diagrams illustrating a configuration example when the light source unit illustrated in FIG. 11 is fixed on a base provided with positioning pins, where FIG. 13A is a plan view and FIG. 13B is a side view.

FIG. 14 is a view showing a configuration in which a concave portion is provided on the base side of the leg instead of the positioning pin, and a convex portion is provided on the base to be fitted with the concave portion, and the convex portion and the concave portion are fitted to each other to perform positioning. It is a figure showing the example of composition at the time of performing.

FIG. 15 shows a case where both legs and the base shown in FIG. 11 are made of a material other than metal, for example, resin, in order to perform laser welding, a metal member is provided at a contact portion between both members. It is a figure showing the example at the time of insert.

FIG. 16A is a perspective view of a light source unit different from the above, and FIG. 16B is a plan view of the light source unit shown in FIG.

17 is a cross-sectional view of the light source unit shown in FIG. 16 taken along line DD.

18 is a cross-sectional view of the light source unit shown in FIG. 16 taken along line EE.

19A and 19B are diagrams illustrating a configuration example of a light source unit using a collimator lens having a shape different from that of the collimator lens of the light source unit, wherein FIG. 19A is a cross-sectional view of the collimator lens, and FIG. FIG.

20 (a) and (b) are cross-sectional views showing examples of a collimator lens having still another shape from FIG.

21A and 21B are diagrams illustrating a configuration example of a light source unit using a lens barrel having a flange provided at one end of a cylinder and a collimator lens provided in the flange, and FIG. And (b) is a sectional view taken along line FF of only the base shown in (a).

22 is a diagram showing a configuration example of a light source unit when a collimator lens having a different shape from that of FIG. 21 is provided in a lens barrel, where (a) is a plan view and (b) is (a) FIG. 3 is a cross-sectional view of the light source unit shown in FIG.

23A and 23B are diagrams illustrating an example of a light source unit having a configuration in which a lens barrel is pressed against a base using an urging force of a leaf spring, and FIG.
Is a plan view, and (b) shows the light source unit shown in (a) by an arrow H.
It is a side view when seen from the direction.

24A and 24B are diagrams illustrating a configuration example of a light source unit using a linear spring instead of the leaf spring, wherein FIG. 24A is a plan view of the light source unit 250, and FIG. 24B is a light source unit of FIG. FIG. 5 is a side view when viewed from the direction of arrow H.

25A and 25B are diagrams illustrating a configuration example of a light source unit using a plunger instead of the leaf spring, wherein FIG. 25A is a plan view of the light source unit, and FIG. 25B is a diagram illustrating the light source unit illustrated in FIG. Arrow sectional view when cut along the line JJ, (c)
It is sectional drawing for showing the structure of a plunger.

FIG. 26 is a diagram illustrating a configuration example of a light source unit that supports a lens barrel using a claw member instead of the leaf spring,
(A) is a plan view of the light source unit, and (b) is a cross-sectional view taken along the line KK of the light source unit of (a).

FIG. 27 is a diagram showing a configuration example in which a cylindrical lens barrel holding block is provided on an L-shaped base, and the lens barrel is supported by being inserted into the lens barrel holding block; (a) is a perspective view and (b) is a plan view.

28A is a cross-sectional view showing an example of a mounting structure of a laser diode, and FIG. 28B is a sectional view of a portion where a stem is soldered to a printed circuit board taken along line MM of FIG. It is arrow sectional drawing at the time of cutting.

FIG. 29 is a cross-sectional view showing a conventional configuration example when a holder for holding a laser diode is provided on a printed board.

FIG. 30 is a cross-sectional view illustrating a configuration example when a laser diode is fixed to a printed circuit board via a steel plate.

31A is a front view showing a configuration of a light source unit different from the above, and FIG. 31B is a side view of the light source unit shown in FIG. is there.

FIG. 32 is a diagram showing an example when the laser diode and the base are welded to three places.

FIG. 33 is a perspective view showing a configuration example of a light source unit configured to hold a laser diode in an LD holding unit provided on a base.

FIG. 34 is a side view of a state where a laser diode is inserted into the LD holding block when viewed from the direction of arrow Q in FIG. 33;

FIG. 35 is a cross-sectional view of the LD holding block section shown in FIG. 34 taken along the line RR.

FIG. 36 (a) shows an example in which the through-hole shown in FIG.
FIG. 4B is a cross-sectional view illustrating an example in which a concave portion is provided in the LD holding block portion, FIG. 4B is a cross-sectional view in which a step portion is provided, and FIG.

FIG. 37 is a sectional view showing an example of a light source unit in which a laser diode is inserted into one of the cylindrical bases and a lens barrel holding a collimator lens is inserted into the other, and these members are integrally formed. is there.

FIG. 38 is a cross-sectional view showing an example of another light source unit in a case where the collimator lens is directly attached to a base and the laser diode, the collimator lens, and the base are integrally formed.

FIG. 39 is a cross-sectional view showing a configuration example of a light source unit in a so-called multi-beam type laser beam scanning device that simultaneously performs exposure scanning on a photosensitive drum using two laser beams.

[Explanation of symbols]

10 Printer head 11, 50, 150, 200, 207, 220, 23
0, 240, 250, 260, 270, 500 Light source unit 12, 204, 301, 506, 602, 609, 61
0 laser diode 13, 83, 85, 203, 205, 209, 210,
226, 233, 283, 504, 604, 606, 6
08 Collimator lens 14 Cylindrical lens 15 Polygon mirror 16 Scanning lens group 17 Base 51, 61, 62, 66, 71, 111, 151, 20
1,221,231,271,281,501,60
1,607 base 55,241 leaf spring 64,67,121-124,153,322,51
3, 611, 621 through hole 75 auxiliary member 81, 86 holding frame 112, 282, 2012 lens barrel holding block part 113, 2011, 6071, 6072 LD holding block part 114 V-shaped groove 131, 202, 225, 232, 284, 505, 6
05 Lens barrel 152, 157 Leg 158, 514 Concave part 171, 174 Projection 172 Pin 173 Convex part 253 Spring 262 Plunger 272 Claw member 302 Laser chip 303, 507, 603 Stem 304 508 Lead 305 Printed circuit board 307 Solder 321 Steel plate 502 LD insertion Hole 511 LD holding part 515 Step part 516 Tapered part 530 Gripping part 2031, 2051, 2091, 2101 Mounting seat surface

Continued on the front page F term (reference) 2C362 AA48 BA90 DA02 DA03 2H045 AA01 CB22 DA02 5C051 AA02 DC05 DC07 DE22 DE23 DE29 5C072 AA03 BA04 CA06 CA09 DA21 DA23 HA02 HB08 5F073 BA07 EA29 FA08 FA23

Claims (5)

[Claims] 1. A light source device for irradiating an object with a light beam emitted from a light emitting element via an optical element, comprising: a holding frame for holding the optical element; A light source device, which is fixed to a base of the light source device by laser welding in a state where the optical position is adjusted. 2. A light source device for irradiating an object with a light beam emitted from a light emitting element via an optical element, comprising: a holding frame for holding the optical element; In a state where the optical position is adjusted, the light source device is located on a plane orthogonal to the optical axis of the optical element and in a plane including the position of the principal point of the optical element or in a plane close thereto. A light source device fixed to the base. 3. A light emitting device mounted on a stem,
A light source device comprising: a circuit board that supplies a drive current to the light-emitting element; wherein the stem has a bottom surface directly fixed to the circuit board by soldering or laser welding. 4. A light emitting device mounted on a stem,
A light source device comprising: a holding member that holds the stem; wherein the stem is fixed to the holding member by laser welding in an optically adjusted state. 5. A light source unit including a light emitting element, a collimator for collimating a light beam emitted from the light emitting element, and a deflector for deflecting the light beam from the light source unit to scan an object to be scanned. A light beam scanning device, wherein the light source unit is fixed to a base portion of the light beam scanning device by laser welding.