JPH07261115A - Laser beam shaper - Google Patents

Abstract

PURPOSE:To easily shape a laser beam of a deflection scan device. CONSTITUTION:A holder 25 is fixed to an optical box 22, and a lens barrel incorporating a collimate lens 31 is fitted into the tip of the holder 25, and a cylindrical lens 33 outside fitted onto the tip of the lens barrel. A pedestal 26 is attached to the rear surface of the holder 25 temporarily tightenably or truly tightenably, and a semiconductor laser light source 27 is pressed into the pedestal 26 to be fixed. At the time of shaping the beam, first of all, the pedestal 26 is adjusted so that the laser beam emitted from the semiconductor laser light source 27 coincides with the optical axis of the collimator lens 31, and is truly tightened to be fixed to the holder 25. Then, the lens barrel 51 is adjusted to be fixed to the holder 25 so that the laser beam transmitting through the collimator lens 31 becomes parallel rays of light. Then, the cylindrical lens 33 is adjusted to be fixed to the lens barrel so that a focal point is focused on a reflection surface of a rotary polygon mirror 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser beam shaper for shaping a laser beam emitted from a semiconductor laser light source in a deflection scanning device such as a laser beam printer.

[0002]

2. Description of the Related Art As a conventional deflection scanning device, one having a structure as shown in FIG. 7 is known. That is, a laser unit 2 for emitting laser light is attached to a side wall of an optical box 1 made of a synthetic resin material, and a cylindrical lens 3 for converting the laser light emitted by the laser unit 2 into parallel light is provided inside the optical box 1. And a rotary polygon mirror 5 that deflects and scans the laser light that has been rotatably driven by the drive motor 4 and has passed through the cylindrical lens 3.

Here, the laser unit 2 is assembled as follows. First, the semiconductor laser light source 7 mounted on the laser drive circuit 6 is press-fitted and fixed in the fitting hole of the base 8, and the electrical contact 9 is soldered to the opposite side of the laser drive circuit 6. Next, the holder 10 is temporarily fixed to the base 8, and the lens barrel 11 is fitted into the fitting hole of the holder 10. The lens barrel 1
A collimator lens 12 is fixed in the inside 1 by screws.

Laser unit 2 assembled in this way
In order to adjust, the base 8 is first moved with respect to the holder 10, the laser light emitted by the semiconductor laser light source 7 is adjusted along the optical axis of the collimator lens 12, and the holder 10 is permanently fixed. Next, the lens barrel 11 is moved in the optical axis direction, the laser light transmitted through the collimator lens 12 is adjusted to be parallel light, and the lens barrel 11 is adhesively fixed to the holder 10.
And when shaping the laser beam of the deflection scanning device,
A pedestal 1a in which the cylindrical lens 3 is provided in the optical box 1.
Move it in the direction of the optical axis, and adjust so that the cylindrical lens 3 is focused on the reflecting surface of the rotary polygon mirror 5.
Adhesively fixed to a.

[0005]

However, in the above-mentioned conventional example, when the optical box 1 is molded from a synthetic resin material, as shown in a partially enlarged perspective view of FIG.
Are pulled toward the adjacent wall portion 1b, the upper surface of the pedestal 1a is bent, the parallelism with respect to the scanning surface is deteriorated, and the cylindrical lens 3 is fixed while tilted, and the laser light cannot be shaped into a desired state. There is.

An object of the present invention is to provide a laser beam shaper capable of favorably shaping laser light by solving the above-mentioned problems.

[0007]

To achieve the above object, a laser beam shaper according to the present invention makes a semiconductor laser light source emitting a laser beam and a laser beam emitted by the semiconductor laser light source a parallel beam. In a laser beam shaper comprising a collimator lens, a lens barrel holding the collimator lens, and a cylindrical lens for shaping the laser light transmitted through the collimator lens,
The cylindrical lens is attached to the lens barrel so as to be movable in the optical axis direction.

[0008]

In the laser beam shaper having the above-mentioned structure, the cylindrical lens is attached to the lens barrel holding the collimator lens so as to be movable in the optical axis direction, and the laser beam emitted from the semiconductor laser light source is moved in the lens barrel. The collimator lens collimates the parallel light, and the parallel light is shaped by moving the cylindrical lens in the optical axis direction.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the embodiments shown in FIGS. 1 is a vertical cross-sectional view of a deflection scanning device having the first embodiment, FIG. 2 is an enlarged vertical cross-sectional view of an essential part, FIG. 3 is a cross-sectional view taken along the line AA of FIG.
Is attached to a side wall 22a of an optical box 22 formed of a synthetic resin material, and a drive motor 24 having a rotary polygon mirror 23 fixed to the upper part thereof is arranged on a bottom wall 22b of the optical box 22. An fθ lens (not shown) is arranged in the optical box 22, and the laser light deflected by the rotary polygon mirror 23 to be scanning light of constant angular velocity is converted to scanning light of constant velocity on a photoreceptor (not shown). It has become so.

In the holder 25 of the laser beam shaper 21, the cylindrical portion 2 is press-fitted and fixed in the fitting hole 22c of the optical box 22.
5a and a flange portion 25b pressed against the side wall 22a of the optical box 22 are provided, and the through hole 25 is provided at the center of the holder 25.
c is provided. On the rear surface of the holder 25, the through hole 2
A base 26 having 6a is temporarily and permanently fastened by screws (not shown). The semiconductor laser light source 27 is attached to the front surface of the base 26, and the laser drive circuit 29 having the electrical contacts 28 soldered to the rear surface thereof is pressed into the through hole 26 a of the base 26. It is fixed.

On the other hand, a lens barrel 30 is fitted to the front portion of the through hole 25c of the holder 25 so as to be movable or fixed in the optical axis direction. The collimator lens 31 is screwed into the lens barrel 30.
The projection 30 is fixed on the upper and lower parts of the front portion of the lens barrel 30 by being fixed by 2.
a and 30b are provided, and a cylindrical lens 33 is fitted to the tip of the lens barrel 30. The cylindrical lens 33 has a lens body 33a and a cylindrical portion 33b, and is integrally molded from synthetic resin. Inside the cylindrical portion 33b, the grooves 33c into which the projections 30a and 30b of the lens barrel 30 are fitted are provided.
3d is provided.

When shaping the laser beam of the deflection scanning device by the laser beam shaper 21 thus constructed, first the base 26 of the laser beam shaper 21 is moved with respect to the holder 25 in a temporarily tightened state. , The laser light emitted from the semiconductor laser light source 27 is adjusted along the optical axis of the collimator lens 31, and then the base 26 is attached to the holder 2
Securely fix to 5. Next, the lens barrel 30 is moved in the optical axis direction, the laser light transmitted through the collimator lens 31 is adjusted to be parallel light, and the lens barrel 30 is adhesively fixed to the holder 25. Finally, the cylindrical lens 33 is moved in the optical axis direction, the focus of the cylindrical lens 33 is adjusted so as to match the reflecting surface of the rotary polygon mirror 23, and the cylindrical lens 33 is adhesively fixed to the lens barrel 30. This allows
The shaping of the laser light of the deflection scanning device is completed.

In the first embodiment, since the cylindrical lens 33 is directly attached to the lens barrel 30 instead of the optical box 22, even if a molding defect occurs in the optical box 22 or other members and a dimensional error is accumulated. The optical axis can be easily adjusted only by providing the coaxiality of the fitting portion between the lens barrel 30 and the cylindrical lens 33.

FIG. 4 is a vertical sectional view of the second embodiment, in which a groove 41b, 41c is provided at the tip of a cylindrical portion 41a of a holder 41, and a lens body 42a of a cylindrical lens 42 is provided.
The cylindrical portion 42b for holding is provided with projections 42c and 42d that fit into the grooves 41b and 41c. The second embodiment has the other operational effects except that the rotation of the cylindrical lens 42 is restricted by fitting the protrusions 42c and 42d of the cylindrical lens 42 into the grooves 41b and 41c of the holder 41. It is similar to the embodiment of.

FIG. 5 is a longitudinal sectional view of the third embodiment, and FIG. 6 is a front view thereof. The lens barrel 51 is elongated, and the lens body 52 of the cylindrical lens 52 is provided on the inner circumference of the distal end of the lens barrel 51.
The tubular portion 52b that holds a is fitted. In order to regulate the rotation of the cylindrical lens 52, projections 52c and 52d are formed on the upper and lower sides of the cylindrical portion 52b, and grooves 51a and 51b for fitting the projections 52c and 52d are formed on the inner peripheral surface of the lens barrel 51. .

The third embodiment has the same function and effect as the first embodiment, and also has a fitting portion between the lens barrel 51 and the cylindrical lens 52, the collimator lens 31 and the lens barrel 51.
Since the fitting portions of the same use the same circumferential surface, the semiconductor laser light source 27 adjusted to the optical axis of the collimator lens 31.
Can be easily positioned on the optical axis of the cylindrical lens 52.

[0017]

As described above, in the laser beam shaper according to the present invention, since the cylindrical lens is attached to the lens barrel so as to be movable in the optical axis direction, the optical axis of the cylindrical lens is adjusted only in relation to the lens barrel. The laser light emitted from the semiconductor laser light source can be shaped easily and accurately.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a deflection scanning device using a first embodiment.

FIG. 2 is an enlarged vertical sectional view of a main part.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is an enlarged vertical sectional view of a main part of the second embodiment.

FIG. 5 is an enlarged vertical sectional view of a main part of the third embodiment.

FIG. 6 is a front view.

FIG. 7 is a vertical cross-sectional view of a conventional deflection scanning device.

FIG. 8 is a partially enlarged perspective view.

[Explanation of symbols]

 21 laser beam shaper 22 optical box 23 rotating polygon mirror 25, 41 holder 26 base 27 semiconductor laser light source 30, 51 lens barrel 31 collimator lens 33, 42, 52 cylindrical lens

Claims (5)

[Claims] 1. A semiconductor laser light source that emits laser light, a collimator lens that collimates the laser light emitted by the semiconductor laser light source, a barrel that holds the collimator lens, and a laser that passes through the collimator lens. A laser beam shaper comprising a cylindrical lens for shaping light, wherein the cylindrical lens is attached to the lens barrel so as to be movable in the optical axis direction. 2. The laser beam shaper according to claim 1, wherein the cylindrical lens is fixed in a cylindrical body, and the cylindrical body is fitted in the lens barrel. 3. The laser beam shaper according to claim 2, wherein the cylindrical body is fitted onto the lens barrel. 4. The laser beam shaper according to claim 2, wherein the cylindrical lens and the cylindrical body are integrally molded from a synthetic resin material. 5. The laser beam shaper according to claim 1, further comprising means for restricting rotation of the cylindrical lens around the optical axis.