JP2910652B2 - Laser light source unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser light source unit, and more particularly, to a laser light source unit provided in an electrophotographic printing apparatus or the like.

[0002]

2. Description of the Related Art A conventional laser light source unit 50 is shown in FIG. This conventional laser light source unit is provided in a laser optical scanning system of an electrophotographic printing apparatus, and aims at irradiating a laser beam to a polygon mirror of the laser optical scanning system.

The conventional laser light source unit 50 comprises a collimating lens 55 and an aperture 54 disposed along the optical path of the laser light in the irradiation direction of a laser light source 52 for emitting the laser light, and a holder member for holding these. 51
It is composed of

A laser optical scanning system is equipped with the laser light source unit 50, and is provided with a toroidal lens provided on the extension of the optical path of the laser beam, and further provided on the extension thereof, and faces the photosensitive drum. A polygon mirror that scans the laser beam, an fθ lens disposed between the polygon mirror and the photosensitive drum, a synchronization signal detection sensor that outputs a synchronization signal by the scanning light, and a chassis that holds the above components. It is mainly composed.

The laser light source unit 50 includes a laser light source 52, a collimating lens 55, and an aperture 54.
4, is linearly held by a holder member 51 along the irradiation direction of the laser light source, and is fixedly mounted on a chassis (not shown) via the holder member 51.

At the time of the exposure operation, the laser light output from the laser light source 52 is transmitted through the collimating lens 55 and converted into a parallel light, and further passes through the aperture 54 to be shaped. . Then, exposure is performed on the outer peripheral surface of the photosensitive drum via a toroidal lens, a polygon mirror, and the like.

[0007]

However, in the above-mentioned conventional example, the holder member 51 is made of aluminum die-cast or plastic mold, and an aperture 54, which is another member, is attached to the holder member 51 later. Had been configured.

When such a holder member 51 is used, it is necessary to perform a complicated positioning operation of the aperture 54 in order to allow the irradiation light from the laser light source 52 to pass through the collimator lens 55 and the aperture 54 and travel in a predetermined direction. It is indispensable, and in addition, since all these are individual members, it has been difficult to improve the positional accuracy.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a laser light source unit which can solve the disadvantages of the prior art and eliminate complicated adjustment of an aperture or the like during assembly.

[0010]

According to the present invention, a laser light source for emitting laser light, a collimating lens for collimating the laser light, and a holder member for holding the laser light source and the collimating lens are provided. Have.

[0011] Then, the holder member is connected to one of the flat plates.
Shape with one end bent and the other end raised
The both ends are opposed to each other, and a laser light source mounting portion is provided at one end of the holder member, and an aperture for shaping laser light into a predetermined shape is formed at a position facing the mounting portion of the other end. Further, a configuration is adopted in which a support portion for the collimating lens is provided at an intermediate portion between the mounting portion of the holder member and the aperture.

In the above configuration, the aperture, the mounting portion of the laser light source, and the collimating lens are so arranged that the irradiation light from the laser light source passes through the collimating lens and is parallelized toward the aperture after the mounting of the laser light source and the collimating lens. The positions of the support portions are set in advance when the holding member is formed.

According to a second aspect of the present invention, in addition to having the same configuration as the first aspect of the invention, the holder member is formed of one sheet metal.

That is, a mounting portion for a laser light source is provided at one end of the metal plate, and an aperture is formed at the other end. A support for the collimating lens is provided at an intermediate portion between them. Each position of the aperture, the mounting portion of the laser light source, and the supporting portion of the collimating lens is such that, after the mounting of the laser light source and the collimating lens, the irradiation light from the laser light source passes through the collimating lens and is parallelized toward the aperture. Is set in advance when processing is performed on this metal plate.

According to a third aspect of the present invention, in addition to having the same configuration as the second aspect of the invention, the holder member is formed by a single sheet metal having a U-shaped cross section.

In the case of the above configuration, a mounting portion for a laser light source is formed on one of two opposing surfaces of a U-shaped metal plate,
An aperture is formed on the other. A support for the collimating lens is provided at an intermediate portion between them. Then, after the laser light source and the collimating lens are mounted, the positions of the aperture, the mounting portion of the laser light source, and the supporting portion of the collimating lens are adjusted so that the irradiation light from the laser light source passes through the collimating lens and is parallelized toward the aperture. Is set in advance when processing is performed on this metal plate.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing the present embodiment, and FIG. 2 is a configuration diagram showing a laser scanning optical unit 20. The present embodiment is provided with a laser scanning optical unit 20 of an electrophotographic printing apparatus, and a laser light source serving as a laser beam irradiation source when performing exposure on a photosensitive drum D provided in the printing apparatus. Unit 3 is shown.

The laser light source unit 3 includes a laser light source 2 composed of a laser diode for emitting laser light, a collimating lens 5 for collimating the laser light, and a holder member 1 for holding the laser light source 2 and the collimating lens 5.
It is mainly composed of

The laser scanning optical unit 20 equipped with the laser light source unit 3 includes a toroidal lens 6 for condensing the laser light from the laser light source unit in a predetermined direction, and a scanning device that reflects the condensed laser light to perform scanning. A polygon mirror 7, a polygon motor 8 for rotating and driving the polygon mirror 7, an fθ lens 9 for condensing the scanned laser light on an image surface on the photosensitive drum D, and a part of the scanned laser light. The apparatus includes a synchronization signal detection sensor 12 that outputs a synchronization signal upon incidence, and a chassis 10 that holds the above-described components at predetermined portions.

As shown in FIG. 1, the holder member 1 of the present embodiment is formed from a single sheet metal having a U-shaped cross section.
The U-shaped opening of the holder member 1 is screwed to the chassis 10 of the laser scanning optical unit 20 with the U-shaped opening facing upward. A mounting hole 1A is formed as a mounting portion for mounting. The mounting hole 1A is formed with a dimension substantially equal to the outer dimension of the laser diode as the laser light source 2, and the laser light source 2 is fixed at a fixed position by being inserted into the mounting hole. .

An aperture 4 is formed on the other side wall of the holder member 1 described above. This aperture 4
Is an elliptical through hole formed through the metal plate constituting the holder member 1 and having an aspect ratio set at a predetermined ratio, and shapes the shape of the laser beam from the laser light source.

Further, a support 1B for the collimating lens is mounted in the middle of each side wall of the holder member 1.
The support portion 1B has a configuration in which a U-shaped metal plate smaller than the holder member 1 is retrofitted, and the collimating lens 5 is fixedly provided inside the metal plate.

The aperture 4 is provided with a laser light source 2 in a mounting hole 1A of the holder member 1 and a support portion 1B.
With the collimating lens 5 mounted on the
When the laser beam is collimated by the collimating lens 5 together with the emission of the laser beam from the laser beam, the collimated laser beam passes through the aperture 4 perpendicularly and exactly to the side wall on which the aperture 4 is provided. This holder member 1
Are formed in a state where the above-mentioned positions are set.

The operation of the laser scanning optical unit 20 equipped with the above-mentioned laser light source unit 3 will be described.

First, the outer peripheral surface of the photosensitive drum D is uniformly charged by charging means (not shown) provided in the printing apparatus in advance. Then, the laser light is emitted from the laser light source 2 and passes through the collimator lens 5, and at this time, the laser light is collimated.

Then, the collimated laser beam passes through the elliptical through hole which is just the aperture 4 from a direction perpendicular to the side wall of the holder member 1 on which the aperture 4 is formed,
Thereby, shaping of the laser light is performed.

Next, the laser light passes through the toroidal lens 6 and is focused in a predetermined direction. In this state, the laser light is reflected by the reflecting surface of the polygon mirror 7 driven by the polygon motor 8 to the photosensitive drum D side. And the scanning is performed in a direction along the rotation axis of the photosensitive drum D.

At this time, the laser light is uniformly focused on the outer peripheral surface of the photosensitive drum D by the fθ lens 9 in the scanning direction. The laser beam is incident on the synchronization signal detection sensor 12 before being irradiated onto the photosensitive drum D, and a detection signal is output from the synchronization signal detection sensor 12 to the control unit of the laser scanning optical unit 20 (not shown) by this incidence. The control unit adjusts the exposure start position on the outer peripheral surface of the photosensitive drum D based on the detection signal by controlling the emission timing of the laser light source.

As described above, in this embodiment, since the aperture 4 is formed directly on the holder member 1, it is not necessary to adjust the mounting position of the aperture 4 when mounting the holder member 1, and Since the aperture 4 and the mounting positions of the laser light source 2 and the collimating lens 5 are previously set to predetermined positions when the holder member 1 is formed, the laser light source 2 and the collimating lens By simply mounting the holder 5 on the holder member, each part can satisfactorily collimate and shape the laser beam.

Further, since the aperture 4 is formed integrally with the holder member 1, the number of components can be reduced, and the productivity of the laser light source unit 3 can be improved. Become.

FIG. 3 shows another example of the holder member. The holder member 31 supports the support portion 31B of the collimator lens 5.
Is provided at an intermediate portion between the two side walls of the holder member 31. That is, the holder 31 has a support portion 31B formed by making two sets of cuts at predetermined positions and standing up from the cuts. Collimating lens 5
Are clamped and fixed between the support portions. Other parts are formed in the same manner as the holder member 1.

The collimating lens 5 sandwiched between the support portions 31B collimates the irradiation light from the laser light source 1 in a direction perpendicular to the side wall on which the aperture 4 is provided, and passes through the aperture 4 so as to pass through the aperture 4. The part 31 is set at the time of its formation.

This has the same effect as the holder member 1 described above, and the holder member 31 can be formed by one component.
1 can improve the productivity.

[0034]

According to the present invention, since the mounting portion for the aperture and the laser light source is formed at a predetermined position in advance, it is not necessary to adjust the position of the aperture at the time of mounting the holder member as in the prior art. Mounting work can be performed.

Further, since the aperture is not a separate member as in the prior art, the number of steps for retrofitting the aperture can be reduced, and the processing accuracy when this aperture is formed on the holder member is improved, thereby realizing the realization. The laser beam emitted from the laser light source at the time of use and collimated by the collimator lens can be sent out in a predetermined direction with high accuracy and can be shaped into a predetermined shape.

Further, since the aperture is formed directly on the holder member, the number of parts can be reduced.
It is possible to improve the productivity of the entire laser light source unit.

In the case where the holder member is formed from a single metal plate, the holder member can be formed by a simple method such as bending, drilling, and cutting the metal plate. Further, it is possible to further improve the productivity of the entire laser light source unit.

Since the present invention is constructed and functions as described above, it is possible to provide an unprecedented excellent laser light source unit.

[Brief description of the drawings]

FIG. 1 is a developed perspective view showing an embodiment of the present invention.

FIG. 2 is a schematic overall configuration diagram of a laser scanning optical unit equipped with the embodiment disclosed in FIG. 1;

FIG. 3 is a perspective view showing another example of a holder member.

FIG. 4 is an exploded perspective view of a conventional laser light source unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Holder member 1A Mounting part 1B Support part 2 Laser light source 4 Aperture 5 Collimating lens

Claims (3)

(57) [Claims] 1. A laser light source for emitting a laser beam, a collimating lens for collimating the laser beam, and a holder member for holding the laser light source and the collimating lens, wherein the holder member is a single flat plate. One end and the other end of
And both ends as a shape that bends and rises
Are opposed to each other, and an aperture for shaping the laser light into a predetermined shape is provided at a position facing the mounting portion at the other end while providing a mounting portion for the laser light source at one end of the holder member. A laser light source unit, wherein a support portion for the collimating lens is provided at an intermediate portion between the mounting portion and the aperture of the holder member. 2. The laser light source unit according to claim 1, wherein said holder member is formed of one sheet metal. 3. The laser light source unit according to claim 2, wherein said holder member is formed of a single sheet metal having a U-shaped cross section.