JPH0645684A - Optical device and laser beam light source using the same - Google Patents

Abstract

PURPOSE:To accurately hold a position of a plastic lens and to accurately irradiate at a predetermined position with a laser beam by providing a pipelike mirror frame to be fixed at its end to the vicinity of an outer periphery of the lens, and fixing the lens without protruding from an end face of the frame. CONSTITUTION:The optical device comprises a pipelike mirror frame 24 fixed at its end to the vicinity of an outer periphery of a plastic lens 23. An outer periphery of the lens 23 is so formed to be smaller than an outer diameter of the end face of the frame 24 as not to extend from the end face of the frame 24 to the outside. The frame 24 is movable in a hole H2 in a bar body 2 in a direction Z, and fixed to the body 2 by a YAG laser welding in a state positioned by the movement. The frame 24 is moved by grasping the frame 24 from both sides by a jig 10, moved toward an arrow m2, and so positioned as to be finely regulated in a micron order with respect to the laser 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device and a laser beam light source using the same, and more specifically to a laser beam printer, a copying machine, a facsimile,
The present invention relates to an optical device used for a phototypesetting machine, a bar code reader, a sensor, etc., and a laser beam light source using the same.

[0002]

2. Description of the Related Art An optical device used in combination with a light emitting device such as a semiconductor laser is used in various devices as described above. For example, in an image forming apparatus such as a laser beam printer, a copying machine, and a facsimile, it is used as a laser beam light source for emitting a laser beam for forming an image such as characters on a photosensitive drum at high speed. In a phototypesetting machine, it is used as a laser beam source for emitting a laser beam for high-speed printing on a film. In bar code readers and various sensors, it is used as a laser beam light source for emitting a laser beam to obtain information by reflected light from a bar code or an object.

In a laser beam light source used in various devices as described above, for example, as shown in FIG. 6, a pair of semiconductor lasers 1 and a glass lens 3 are mounted on a bar body 2 which is a fixing member. It has a fixed configuration.
A hole H is formed in the bar body 2 at a position facing each other through the groove 5.
1, H2 are formed. A semiconductor laser 1 is attached to the hole H1, and a lens frame 4 having a lens 3 fixed therein is inserted and fixed in the hole H2. The fixing of the lens 3 is performed by applying the contact surface S2a provided on the inner peripheral surface of the lens frame 4,
This is performed by applying an adhesive to S2b. In addition, the semiconductor laser 1 and the lens frame 4 for the bar body 2
Is fixed by a YAG laser.

Positioning of the lens 3 with respect to the lens frame 4 is carried out by contact between contact surfaces formed so as to correspond to the lens 3 and the lens frame 4, respectively. Lens 3
For each of the lens barrel 4 and the lens frame 4, S2a is a contact surface for preventing tilting, and S2b is a contact surface for preventing eccentricity.

The semiconductor laser 1 is positioned by moving the semiconductor laser 1 along a plane perpendicular to the optical axis AX1 (arrow m1). That is, the semiconductor laser 1 is partially inserted into the hole H1 and is adjusted / positioned in the X and Y directions with the surface S1 formed perpendicular to the optical axis AX1, and then the YAG laser welding is performed at that position. By performing the above, the semiconductor laser 1 is fixed.

The positioning of the lens frame 4 is performed by moving the lens frame 4 in the hole H2 along the optical axis AX2 direction (Z direction).
(Arrow m2). The movement of the lens frame 4 is performed by moving the jig 30 that is in contact with both end faces of the lens frame 4 along the optical axis AX2 of the lens 3 (arrow m2) as shown in FIG. Since the jig 30 is provided with the opening 32 in the portion serving as the optical path, the laser beam emitted from the semiconductor laser 1 (FIG. 6) is not blocked by the jig 30. Therefore, the position of the lens 3 can be adjusted until the fixing of the lens frame 4 is completed while obtaining information on the beam such as the focus position, the tilt of the beam, and the parallelism.
The method of adjusting the position of the lens frame is proposed by the applicant in Japanese Patent Application No. 3-302279.

On the other hand, a general compact disc player has conventionally used an optical device including a plastic lens 13 and a lens frame 14 as shown in FIGS. 8 and 9. FIG. 8 shows a perspective view of the optical device, and FIG. 9 shows a longitudinal sectional view thereof. The lens 13 includes a lens portion 17 for converging a laser beam, a collar 15 forming an outer peripheral portion thereof,
It is composed of a ring-shaped fitting portion 16 (FIG. 9) formed so as to come into contact with and fit to the inner peripheral surface of the lens frame 14. Mating part 1
The abutting surface S3b of 6 allows the lens portion 17 to be centered with respect to the lens frame 14 and prevents eccentricity. Further, the contact surface S3a of the collar 15 can prevent the lens 13 from tilting with respect to the lens frame 14. The collar 15 is fixed to the end of the lens frame 14 with an adhesive, but due to the structure of the compact disc player, the collar 15 has a structure protruding from the lens frame 14.
Then, with a coil (not shown) attached to the lens frame 14,
Autofocusing is performed by electrically moving the lens frame 14.

[0008]

In the optical device (FIGS. 6 and 7) in which the glass lens 3 is used, since the lens frame 4 is long along the optical path, the tilt in directions other than the Z direction is not provided. There is a merit that it is unlikely to occur. However, since the lens 3 is positioned with respect to the lens frame 4 in a state where the lens 3 is placed in the lens frame 4, there is a problem that workability is poor and positioning is difficult. As a result, it becomes difficult to properly bring the lens 3 and the lens frame 4 into contact with each other on the contact surfaces S2a and S2b, and the optical characteristics are likely to deteriorate. Further, since the lens 3 is fixed to the lens frame 4 by the adhesive 7 filled in the hole 8, there is a problem that the fixing strength is low and unstable.

On the other hand, in the optical device using the plastic lens 13 (FIGS. 8 and 9), since the lens 13 is fixed at the end of the lens frame 14, workability is good and positioning is easy, and fixing strength is high. It is also high and stable. Moreover, since the plastic lens has good workability and is inexpensive, it is possible to reduce the cost of the device. However, as described above, since the flange 15 is configured to be larger than the outer diameter of the lens frame 14, the collar 15 is inserted and fixed in the hole formed in the bar body as in the conventional example shown in FIGS. It is difficult to apply it to the purpose of adjusting the position automatically.

For example, if a semiconductor laser is simply applied to the bar body for positioning, and a lens in a lens frame of an appropriate length is applied to the reference surface and bonded, a substantially parallel laser beam can be obtained. However, the length of each component varies, so even if the dimensional accuracy is increased,
Only mechanical positioning accuracy of about 0 μm can be obtained. Therefore, the optical device shown in FIGS. 8 and 9 cannot perform optical positioning by moving the lens frame 14,
It cannot be applied to applications that require highly accurate positioning of ± 5 μm.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an optical device capable of highly accurate positioning by movement within a space formed in a fixed member.

Another object of the present invention is to provide a laser beam light source capable of accurately emitting a laser beam to a predetermined position.

[0013]

In order to achieve the above object, an optical device of the present invention comprises a plastic lens and a pipe-shaped lens frame fixed at its end to the vicinity of the outer periphery of the plastic lens. The optical device is characterized in that the plastic lens is fixed so as not to protrude outward from the end face of the lens frame.

The laser beam light source of the present invention is a semiconductor laser, a lens for guiding the laser beam emitted from the semiconductor laser to a predetermined position, a pipe-shaped lens frame for fixing the lens, and the semiconductor laser. And a fixing member for fixing the semiconductor laser and the lens frame so that the lens and the lens face each other,
The lens is a plastic lens fixed at the end of the lens frame with respect to the vicinity of the outer periphery so that the lens does not protrude outward from the end surface of the lens frame, and the lens frame is formed on the fixing member. It is characterized in that it is fixed to the fixing member while being positioned by moving in the space.

[0015]

According to such a structure of the optical device, since the plastic lens is fixed so as not to protrude from the end surface of the lens frame to the outside, for example, the lens frame is inserted into the space formed in the fixing member, Even when the plastic lens is positioned, the movement of the lens frame is not limited by the plastic lens, and the lens position can be finely adjusted.

Further, according to the structure of the laser beam light source, since the lens is fixed at the end of the lens frame with respect to the vicinity of the outer periphery thereof, the lens frame and the lens are strongly fixed and stable, and the plastic The position of the laser beam emitted from the lens is kept stable.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a sectional view showing a state in which the optical device of the present embodiment is positioned in a hole H2 of a bar body 2 which is a fixing member, and FIG. 2 is a perspective view showing an appearance of the optical device of the present embodiment,
FIG. 3 is a sectional view thereof, and FIG. 4 is an external perspective view of a multi-channel laser beam light source in which a plurality of bar bodies 2 to which the present embodiment is fixed are fixed to a substrate 50. Incidentally, FIG.
The same parts as those of the conventional example shown in FIG. 9 are designated by the same reference numerals, and detailed description thereof will be omitted.

The optical device of this embodiment shown in FIGS. 2 and 3 has a plastic lens 23 and a plastic lens 2.
3 is composed of a pipe-shaped lens frame 24 fixed at the end portion to the vicinity of the outer peripheral portion of 3, and the outer diameter of the plastic lens 23 is set so that the plastic lens 23 does not protrude from the end surface of the lens frame 24 to the outside. It is formed smaller than the outer diameter of the end portion of the lens frame 24. Therefore, the lens frame 24 is the bar body 24.
It is movable in the Z direction within the hole H2 formed therein. The lens frame 24 is fixed to the bar body 24 by YAG laser welding while being positioned by the movement. The lens frame 24 and the plastic lens 23 are adhered to each other by applying an adhesive to the contact surfaces S4a and S4b (FIG. 3) and bringing them into contact with each other. The contact surfaces S4a and S4b are the lens frame 24 of the plastic lens 23.
It is also used as a reference surface for positioning with respect to and an adhesive fixing surface.

The lens frame 24 is moved by grasping the lens frame 4 from both sides with the jig 10 and moving it as indicated by an arrow m2. By this operation, positioning can be performed on the semiconductor laser 1 by fine adjustment on the order of microns (about ± 5 μm). The groove 5 is formed in the center of the bar body 2 by pushing or pulling the lens frame 20 as shown in FIG. 1 with the lens frame 24 inserted in the hole H2. This is to make adjustments.
Instead of the jig 10, a jig 30 having the opening 32 used in the conventional example (FIG. 7) may be used.

The semiconductor laser 1 is a package equipped with one semiconductor laser chip that emits one laser beam and a monitoring photodiode, and the intensity of laser emission of each semiconductor laser 1 is monitored by the photodiode. Is controlled. Then, as shown in FIG. 1, the semiconductor laser 1 has the tip portion inserted into the hole H1 and the semiconductor laser 1
Is partially fixed to the reference surface S1 by welding with a YAG laser or the like. That is, by externally inserting the small-diameter portion of the semiconductor laser 1 including the small-diameter portion and the flange-shaped large-diameter portion into the hole H1 and bringing the large-diameter portion into contact (contact) with the reference surface S1, After positioning by S1,
It is fixed by YAG laser welding.

The bar body 2 has eight holes H1 for inserting the semiconductor laser 1 formed in an array through the groove 5, and another hole H2 for inserting the lens frame 24 in the other. Eight arrays are formed. Hole H1 and hole H2
Means that, when the semiconductor laser 1 and the lens frame 24 are respectively inserted as shown in FIG. 1, the positions are opposite to each other so that the positions of the optical axes AX1 and AX2 can be adjusted, and they are required respectively. Are arranged in an array of laser beams. Then, a plastic lens 23 is provided in pairs with the semiconductor laser 1 so that eight channels are provided in the bar body 24 so that the laser beam emitted from the semiconductor laser 1 becomes parallel light and is guided to a predetermined position.

As shown in FIG. 4, the optical device (FIG. 2,
(Fig. 3) and the bar body 2 to which the semiconductor laser 1 is fixed
However, a plurality of laser beam light sources are configured by fixing a plurality of them to the substrate 50. Specifically, the bar bodies 2 in which the semiconductor lasers 1 are fixed in one row in the X direction are stacked in the Y direction by fixing the bar bodies 2 to the substrate 50 with screws 54 so that the rows of the lens frame 24 are arranged at equal intervals. It is a two-dimensional array. The electrical connection to the semiconductor laser 1 is made through the opening 52 of the substrate 50.

Also, depending on the application, one bar body 2
8 channel laser beam light source, or 1
A pair of semiconductor laser 1, lens 23 and lens frame 24,
By attaching to a bar body with a pair of holes,
You may comprise a 1-channel laser beam light source.

In the case of this embodiment, the distance between the semiconductor laser 1 and the plastic lens 23 can be made small, so that it is suitable when the focal length of the lens 23 is short or when it is configured to emit a divergent light beam. .

Since this embodiment is assembled by a simple operation of adhering the lens 23 to the end portion of the lens frame 4, the lens must be set at a predetermined position in the lens frame 4.
It can be said that the workability is superior to (Figs. 6 to 9).

In the case of the conventional example using the glass lens 3
In FIGS. 6 and 7, the holes 8 provided in the lens frame 4 are fixed by filling the adhesive 7, but in the present embodiment, the entire circumference of the end of the lens frame 24 and the lens 23. Since the fixing is performed by adhering to the entire circumference of the brim 25, it is not necessary to form a hole in the lens frame or to fill the adhesive. Moreover, since the bonding surface is wide and the direction of bonding is small, the fixing is stable.

Further, since the plastic lens 23 can perform the centering of the lens itself with higher accuracy and the processing is easier than the glass lens 3, the laser beam can be emitted with high accuracy. it can. Moreover, since the plastic lens 23 is lower in cost, it is preferable in terms of cost reduction of the optical device. Further, it is difficult to form the plastic lens 23 having the collar 25 with a glass lens.

Further, as described above, it is difficult to form the abutting surfaces such as the abutting surfaces S2a and S2b of the lens frame 4 (FIGS. 6 and 7) which require high precision inside the lens frame. . On the other hand, in the lens frame 24 used in the present embodiment, the abutting surfaces S4a and S4b that require high accuracy are the lens frame 2
Since it is located at the end of No. 4, it is extremely easy to process and process.

FIG. 5 shows another embodiment of the present invention. The lens 23 has the same configuration as that of the above-described embodiment except that the fixing position of the lens 23 with respect to the lens frame 24 is the end portion on the opposite side of the fixing position with respect to the lens frame 24 of the above-described embodiment shown in FIG. In this embodiment, the semiconductor laser 1 and the lens 23
Since the distance between and can be made large, it is suitable when the focal length of the lens 23 is long or when the lens 23 is configured to emit a convergent ray.

[0030]

As described above, according to the present invention, since the plastic lens is fixed so as not to protrude outward from the end surface of the pipe-shaped lens frame, when the lens frame is fixed to the fixing member and used, The movement of the lens frame in the longitudinal direction within the space formed in the fixing member is not limited. Therefore, it is possible to realize an optical device capable of highly accurate positioning by moving in the space formed in the fixing member. Moreover, since a plastic lens that is low in cost and excellent in workability is used as the lens, the cost of the optical device can be reduced. Further, since the pipe-shaped lens frame is configured to be fixed at the end portion with respect to the vicinity of the outer peripheral portion of the plastic lens, compared to the conventional optical device in which the hole formed in the lens frame is filled with the adhesive, The lens frame and lens are firmly fixed and stable, and the workability when fixing is also excellent.

Further, according to the present invention, the plastic lens is fixed to the vicinity of the outer peripheral portion at the end of the lens frame so that the plastic lens does not protrude outward from the end face of the lens frame, and the lens frame is formed on the fixing member. Since it is fixed to the fixing member while being positioned by moving in the space, the position of the plastic lens is held with high accuracy, and a laser beam light source that can accurately emit a laser beam to a predetermined position is provided. Can be realized.

[Brief description of drawings]

FIG. 1 is a sectional view showing a positioning operation according to an embodiment of the present invention.

FIG. 2 is a perspective view showing the appearance of an embodiment of the present invention.

FIG. 3 is a sectional view of an embodiment of the present invention.

FIG. 4 is a perspective view showing an appearance of a laser beam light source configured according to an embodiment of the present invention.

FIG. 5 is a sectional view showing the positioning operation of another embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a fixed state of a conventional example.

FIG. 7 is a sectional view showing a positioning operation of a conventional example.

FIG. 8 is a perspective view showing the appearance of another conventional example.

FIG. 9 is a cross-sectional view showing another conventional example.

[Explanation of symbols]

 1 ... Semiconductor laser 2 ... Bar body 5 ... Groove 10 ... Jig 23 ... Plastic lens 24 ... Lens frame 25 ... Tsuba 26 ... Fitting part 27 ... Lens part 50 ... Substrate AX1 ... Semiconductor laser optical axis AX2 ... Lens light Shafts H1, H2 ... Hole S1 ... Reference surface S4a ... Tilt prevention contact surface S4b ... Eccentricity prevention contact surface

Claims (2)

[Claims] 1. An optical device comprising a plastic lens and a pipe-shaped lens frame fixed at an end portion to the vicinity of an outer peripheral portion of the plastic lens, wherein the plastic lens is outward from an end surface of the lens frame. An optical device which is fixed so as not to protrude. 2. A semiconductor laser, a lens for guiding a laser beam emitted from the semiconductor laser to a predetermined position, a pipe-shaped lens frame for fixing the lens, and the semiconductor laser and the lens facing each other. A laser beam light source comprising the semiconductor laser and a fixing member for fixing a lens frame, wherein the lens is fixed at an end portion of the lens frame with respect to a vicinity of an outer peripheral portion so that the lens does not protrude outward from an end surface of the lens frame. Laser beam light source, characterized in that the lens frame is fixed to the fixing member in a state in which the lens frame is positioned by moving in the space formed in the fixing member. .