JPH1172729A - Multibeam scanning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust the interval of laser beam spots by simple rotational adjustment. SOLUTION: A laser unit 21 is composed of a semiconductor laser beam source 22, a holder 23 and a lens barrel 25 with a buit-in collimator lens 24. The semiconductor laser beam source 22 is fixed to the holder 23 by force-fitting or adhesion and the holder 23 is stuck/fixed to the lens barrel 25 with the buit-in collimator lens 24. The laser unit 21 is temporarily fixed to the force-fitted hole 27 of an optical box 26. Thereafter, the adjustment of the interval of sub- scanning pitches is performed by rotating the laser unit 21 in the direction B-B'. The rotational adjustment in the direction B-B' is performed by inserting a rotation adjusting pin 31 provided on a rotation adjusting jig 30 into a rotation adjusting hole 29 provided on the holder 23 and rotating the rotation adjusting jig and the rotation adjustment is completed when the interval becomes a pitch interval corresponding to the prescribed resolving power.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-beam scanning device used for optical writing in a laser printer, a digital copying machine, or the like.

[0002]

2. Description of the Related Art In a conventional multi-beam laser unit 1 of this type, for example, as shown in FIG.
Is fixed by press-fitting or bonding. After this fixation, the lens barrel 5 containing a collimator lens (not shown) is moved to the XYZ 3
The direction is adjusted and fixed to the holder 3.

[0003] In this manner, it is necessary to fix the adjusted laser unit 1 to an optical box 8 shown in FIG. 8 which incorporates optical components such as an fθ lens 6 and a rotating polygon mirror 7, for example. As shown in FIG. 9, in order to adjust the plurality of spots S on the photoconductor at a predetermined pitch D in the sub-scanning direction, it is necessary to adjust the rotation of the laser unit 1 in the AA 'direction shown in FIG. is there. For example, this pitch interval D has a resolution of 600 DPI (dots / inch).
In this case, a very fine pitch interval of about 42 μm and about 21 μm at 1200 DPI needs to be adjusted to about ± several μm.

[0004] Such rotation adjustment in the AA 'direction is performed by inserting the holder 3 into the press-fitting hole 9 of the optical box 8 and then adjusting the male screw 1.
0 into the long hole 11 provided in the holder 3,
After the screw is screwed into the female screw hole 12 provided in the optical box 8, the rotation of the laser unit 1 is adjusted with respect to the optical box 8, and then the male screw 10 is tightened and fixed.

[0005]

However, in the above-mentioned prior art, if the laser unit 1 is re-tightened to fix the holder 3 after the rotation adjustment, the laser unit 1 is deformed or moved, and the adjusted pitch interval D is out of order. Sometimes. Further, if the holder 3 is bonded after the rotation adjustment, the holder 3 may be deformed by the adhesive, and the adjusted pitch D may be similarly changed. Further, there is a problem that the sub-scanning pitch interval D is different between a high temperature and a low temperature due to a difference in the coefficient of thermal expansion between the holder 3 and the optical box 8.

When the laser unit 1 is rotated, as shown in FIG.
In some cases, the optical box 8 may protrude downward from the bottom surface of the optical box and cannot be stably installed.

An object of the present invention is to solve the above-mentioned problems,
It is an object of the present invention to provide a multi-beam scanning device that realizes simple rotation adjustment and downsizing of the device.

[0008]

According to the present invention, there is provided a multi-beam scanning apparatus, comprising: a semiconductor laser light source having a plurality of light emitting points; a holder for holding the semiconductor laser light source; In a multi-beam scanning apparatus having a laser unit having a collimator lens that converts a beam into substantially parallel light, various lenses for deflecting and scanning toward a photoconductor, and an optical box having a built-in deflector, When the holder is mounted on a box, the holder is press-fitted into a press-fitting hole of the optical box.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the embodiments shown in FIGS. FIG. 1 is an exploded perspective view of the first embodiment. A laser unit 21 includes a semiconductor laser light source 22, a holder 23, and a lens barrel 25 in which a collimator lens 24 is built. The semiconductor laser light source 22 is fixed to the holder 23 by press-fitting or bonding,
The holder 23 is bonded and fixed to the lens barrel 25. When the holder 23 is bonded and fixed to the lens barrel 25, the holder 23 is adjusted in three directions of XYZ with respect to the semiconductor laser light source 22. The laser unit 21 is fixed to the press-fit hole 27 of the optical box 26.

When the laser unit 21 is mounted on the optical box 26, the press-fitting portion 28 provided on the holder 23 is lightly pressed into the press-fitting hole 27 of the optical box 26, so that the laser unit 21 Is temporarily fixed. The light press-fitting here means from several μm to at most several tens μm.
For example, the outer diameter of the press-fit portion 28 of the holder 23 is finished with a dimensional tolerance of +0.002 mm to +0.017 mm, and the inner diameter of the press-fit hole 27 is 0.000 mm to -0.03 mm.
When the dimensional tolerance is 015 mm, the maximum is 0.032.
mm, a minimum press-fitting margin of 0.002 mm. With this degree, the holder 23 can be press-fitted with almost no deformation.

Thereafter, the laser unit 21 is connected to the B-
Adjustment of the sub-scanning pitch interval is performed by rotating in the direction B '. Rotation adjustment jig 3 for BB 'direction
The rotation adjustment jig 30 is rotated while the rotation adjustment jig 30 is rotated by fitting the rotation adjustment pin 31 provided on the rotation adjustment jig 30 into the rotation adjustment hole 29 provided on the holder 23. When the pitch interval corresponding to the predetermined resolution is reached, the rotation adjustment is completed.

FIG. 2 shows a laser unit 2 according to a second embodiment.
1 shows a sectional view. The same reference numerals as those in the first embodiment denote members having the same functions, and a description thereof will be omitted. In the second embodiment, a concave portion 41 having a level difference enough to embed the plate portion of the holder 23 is provided on the surface of the optical box 26. The procedure for press-fitting the press-fit portion 28 into the press-fit hole 27 is the same as that in the first embodiment.

By embedding the holder 23 in the recess 41 in this manner, there is no possibility that the holder 23 projects outside the optical box 26 as shown in FIG. The possibility of addition is reduced, and a predetermined sub-scanning pitch interval after adjustment can be maintained.

FIG. 3 shows a third embodiment, in which a plurality of strip-shaped ridges 42 are arranged on the outer peripheral surface of the press-fit portion 28 of the holder 23 in the longitudinal direction. The circumferential length of the press-fitting portion 28 of the holder 23 is shortened by these ridges 42, and the press-fitting into the press-fitting hole 27 can be reduced.

FIG. 4 shows a fourth embodiment. In order to obtain the same effect with respect to the press-fit hole 27 of the optical box 26, FIG.
A plurality of concave ridges 43 are also formed on the inner peripheral surface of the press-fit hole 27 in the longitudinal direction. This makes it possible to reduce the force input into the press-fit hole 27 and reduce the deformation of the holder 23.

FIG. 5 shows a fifth embodiment, in which D-cut portions 44 are provided on both side surfaces of the base of the cylindrical holder 23. The semiconductor laser light source 22 is press-fitted or fixed to a holder 23, and a press-fit portion 28 is provided at a position substantially outside the semiconductor laser light source 22. When the press-fitting portion 28 is press-fitted into the press-fitting hole 27 of the optical box 26, the press-fitting portion 28 is provided substantially at the position outside the semiconductor laser light source 22, so that the focus of the laser unit 21 due to the deformation of the holder 23 at the time of press-fitting. Fluctuations and irradiation position fluctuations hardly occur.

Thereafter, the claw portion of the rotation adjusting jig 50 is fitted to the D cut portion 44, and the rotation of the holder 23 is adjusted in the direction CC '. Also in this case, since the D-cut portion 44 is provided near the press-fit portion 28, focus variation and irradiation position variation in the laser unit 21 hardly occur.

FIG. 6 shows a sixth embodiment, in which a press-fit portion 28 is provided substantially outside the semiconductor laser light source 22.
The D-cut 45 for rotation adjustment is provided at the tip of the holder 23.

As described above, even if the D-cut portion 45 is provided at the tip of the holder 23, the rotation of the holder 23 can be adjusted using the rotation adjusting jig 50 from the inside of the optical box 23.
Focus fluctuation and irradiation position fluctuation of the laser unit 21 can be effectively suppressed.

[0020]

As described above, in the multi-beam scanning apparatus according to the present invention, since the holder is press-fitted into the optical box, it is not necessary to retighten the holder after rotation adjustment, and the focus may fluctuate again. The irradiation position does not change.

Further, if the holder is prevented from protruding out of the optical box, it is possible to prevent the holder from accidentally touching the holder during the assembling operation to cause a change in focus or a change in irradiation position.

Further, if any one of the inner periphery of the press-fitting hole of the optical box and the outer periphery of the press-fitting portion of the holder has irregularities, the press-fitting can be eased and the rotation can be easily adjusted.

Further, if the press-fitting portion of the holder is located substantially outside the semiconductor laser light source, the holder is not deformed, so that focus and irradiation position fluctuation do not occur.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a first embodiment.

FIG. 2 is a sectional view of a second embodiment.

FIG. 3 is a perspective view of a third embodiment.

FIG. 4 is a perspective view of a fourth embodiment.

FIG. 5 is a perspective view of a fourth embodiment.

FIG. 6 is a perspective view of a sixth embodiment.

FIG. 7 is a perspective view of a conventional example.

FIG. 8 is a perspective view of a conventional scanning optical device.

FIG. 9 is an explanatory diagram of a sub-scanning interval of a spot.

FIG. 10 is an explanatory diagram of a state where a laser unit protrudes below an optical box.

[Explanation of symbols]

 Reference Signs List 21 laser unit 22 semiconductor laser light source 23 holder 25 lens barrel 26 optical box 27 press-in hole 28 press-in portion 29 rotation adjusting hole 30, 50 rotation adjusting jig 41 concave portion 42 convex streak 43 concave streak 44, 45 D cut portion

Claims (4)

[Claims] 1. A laser unit having a semiconductor laser light source having a plurality of light emitting points, a holder for holding the semiconductor laser light source, a collimator lens for making the emitted beam substantially parallel light, and deflection scanning toward a photosensitive member. In a multi-beam scanning apparatus having an optical box having a built-in deflector and various lenses for performing the operation, when the laser unit is mounted on the optical box, the holder is press-fitted into a press-fit hole of the optical box. Multi-beam scanning device. 2. The multi-beam scanning scan according to claim 1, wherein the holder does not protrude outside the optical box. 3. The multi-beam scanning apparatus according to claim 1, wherein one of an inner periphery of the press-fitting hole of the optical box and an outer periphery of the press-fitting portion of the holder has an uneven surface. 4. The multi-beam scanning device according to claim 1, wherein the press-fit portion of the holder is located substantially outside the semiconductor laser light source.