JPH09187987A - Laser beam scanning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve productivity and reduce cost by eliminating a sensor fixing means and reducing labor for assembling. SOLUTION: There are provided a laser diode assembly body 1 in which a laser diode is integrated, a polygon mirror 2 which reflectively scans a modulated laser to be outputted from the laser diode so as to form a predetermined electrostatic latent image on a photosensitive body, a circuit substrate 3 equipped with a drive circuit for operating the laser diode, and a synchronous sensor 4 witch is held by the circuit substrate 3 and detects synchronous information from the output of the laser diode and inputs it. A hard material is used for the circuit substrate 3 and the synchronous sensor 4 is directly fixed to the hard circuit substrate 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser beam scanning device, and more particularly to a laser beam scanning device forming a part of an electrophotographic system.

[0002]

2. Description of the Related Art As shown in FIG. 2, a conventional laser beam scanning device includes a laser diode assembly 51 and a laser diode drive circuit (not shown) for driving a laser diode in the laser diode assembly 51. , A film printed circuit (FPC: Flexible Printed Circuit) 53 incorporating this laser diode drive circuit, and a polygon mirror 5 for reflecting and scanning the laser light output from the laser diode assembly 51 toward a photoreceptor not shown.
2 is provided.

Further, the film-shaped printed circuit 5 described above is used.
A synchronization sensor (SYNC sensor) 54 is connected to 3 with its foot length adjusted appropriately. The laser light output from the laser diode assembly 51 is reflected and scanned by the rotating polygon mirror 52, and the scanning timing is detected by the synchronization sensor 54.

[0004]

However, the synchronization sensor 54 must be attached to the film-like printed circuit 53 after the terminal is processed by cutting or the like.
In addition, since the film-shaped printed circuit 53 is thin when mounting, there is a disadvantage that another sensor fixing means is required, so that the assembly is troublesome and the film-shaped printed circuit 53 is relatively expensive. Therefore, there is an inconvenience that the cost becomes high as a whole.

[0005]

It is an object of the present invention to improve the disadvantages of the conventional example, particularly to eliminate the need for a sensor fixing means and to reduce the labor for assembling, thereby improving the productivity and reducing the cost of the laser beam. It is an object to provide a scanning device.

[0006]

In order to achieve the above object, according to the invention of claim 1, a laser diode assembly in which a laser diode is incorporated and a modulated laser outputted from the laser diode are reflected and scanned. And a polygon mirror that forms a predetermined electrostatic latent image on the photoconductor,
A circuit board equipped with a drive circuit for driving the laser diode and a synchronization sensor that is held by the circuit board and detects and inputs synchronization information from the output of the laser diode are provided. A hard material is used as the circuit board, and the synchronous sensor is directly fixed to the hard board.

Therefore, in the invention according to claim 1,
The laser light emitted from the laser diode which is the light source in the laser diode assembly 1 is reflected by the polygon mirror 2 and is incident on the synchronous sensor 4 attached to the hard circuit board 3, whereby the laser light scanning timing is obtained. The synchronous sensor 4 for detecting is attached to the commercially available circuit board 3 without requiring any fixing means. Therefore,
The number of parts and the number of assembly steps can be surely reduced.

According to the second aspect of the invention, the above-mentioned hard substrate is fixedly mounted on the laser diode assembly. Even in this case, it is possible to obtain the laser beam scanning device having the same function as that of the invention described in claim 1.

According to a third aspect of the present invention, the synchronous sensor described above is configured to be fixedly mounted on a hard substrate via a relatively long terminal. Even in this case, it is possible to obtain the laser beam scanning device having the same function as that of the invention described in claim 1.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIG.
It will be described based on.

In FIG. 1, reference numeral 1 indicates a laser diode assembly incorporating a laser diode. Reference numeral 2 indicates a polygon mirror. The polygon mirror 2 functions to form a predetermined electrostatic latent image on a photoconductor (not shown) by reflecting and scanning the modulated laser beam output from the laser diode in the laser diode assembly 1. Reference numeral 3 indicates a circuit board. This circuit board 3
Is equipped with a drive circuit which is formed of a hard member and drives the above-mentioned laser diode.

The circuit board 3 is directly mounted with a synchronization sensor 4 which receives the output of the laser diode and detects the synchronization information of the scanning laser light. The circuit board 3 made of a hard member is fixedly mounted on the laser diode assembly described above. Further, the above-mentioned synchronous sensor is fixedly mounted on the circuit board 3 made of a hard member via a relatively long terminal.

The laser light emitted from the laser diode, which is the light source in the laser diode assembly 1, is reflected by the polygon mirror 2 and is incident on the synchronous sensor 4 mounted on the circuit board 3, whereby the laser light is emitted. The scanning timing is detected. The synchronization sensor 4 is attached as it is on the market.

[0014]

As described above, according to the present invention, a synchronous sensor is mounted in a commercially available form, and a special holder is required for mounting the synchronous sensor, unlike the case of the conventional example described above. Therefore, it is possible to surely reduce the number of parts and the number of assembling steps. Therefore, it is possible to provide an excellent laser beam scanning device which has not been available in the related art and which can effectively achieve improvement in productivity and cost reduction. be able to.

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

FIG. 2 is a schematic perspective view showing a conventional example.

[Explanation of symbols]

 1 Laser diode assembly 2 Polygon mirror 3 Circuit board 4 Synchronous sensor

Claims (3)

[Claims] 1. A laser diode assembly incorporating a laser diode, and a polygon mirror for reflecting and scanning a modulated laser output from the laser diode to form a predetermined electrostatic latent image on a photoreceptor. A circuit board equipped with a drive circuit for driving the laser diode,
A synchronous sensor that is held on this circuit board and detects and inputs synchronization information from the output of the laser diode, and a hard material is used as the circuit board, and the synchronization sensor is directly fixed to the hard board. A laser beam scanning device characterized by. 2. The laser beam scanning device according to claim 1, wherein the hard substrate is fixedly mounted on the laser diode assembly. 3. The laser beam scanning device according to claim 1, wherein the synchronization sensor is fixedly mounted on the hard substrate via a relatively long terminal.