JPH11142770A - Optical scanning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To radiate the generated heat of a polygon motor to the outside and to suppress the rise of inner temp. by forming a motor hood for hermetically sealing the polygon motor and a cover for covering a laser diode(LD) assembly, the polygon motor and a f-θ lens both by metal and closely adhering them to each other. SOLUTION: A transmission window 5a formed by a transparent material such as glass is provided in a part through which a laser beam is passed and a motor hood 5 hermetically sealing a polygon motor 3 is formed by metal having good thermal conductivity. A cover 6 formed by metal having good thermal conductivity is mounted on the upper surface of an optical housing 1, a LD assembly 2, a polygon motor 3 covered by a motor hood 5 and a f-θ lens 4 are covered by the cover, the motor hood 5 and the cover 6 are closely adhered and connected by a screw 7. Consequently, the generated heat of the polygon motor 3 is transferred from the motor hood 5 to the cover 6, radiated to the outside, the rise of inner temp. of the motor hood 5 is suppressed and the upper limit of operating condition of the polygon motor is not exceeded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical scanning device used in an electrophotographic image forming apparatus, and more particularly to an optical scanning device which performs scanning by rotating a polygon motor.

[0002]

2. Description of the Related Art FIG. 5 is an exploded perspective view showing an example of a conventional optical scanning device, and FIG. 6 is a sectional view taken along the line CC of the example of FIG.

[0003] Among the optical scanning devices used in an electrophotographic image forming apparatus, a conventional optical scanning device that performs scanning by rotating a polygon motor, in particular, is a box-shaped optical scanning device as shown in FIGS. On the bottom plate of the housing 21,
Laser diode assembly (LD assembly) having laser diode (LD) as light emitting source and collimating lens
A polygon motor 23 having a polyhedral reflecting mirror for reflecting a laser beam emitted from the LD assembly 22;
An f-θ lens 24 for condensing laser light reflected by a polyhedral reflecting mirror when a polygon motor 23 is rotated on a surface of a photoconductor (not shown) is mounted. In order to prevent the generated noise from leaking outside, a motor hood 25 having a transmission window 25a made of a transparent material such as glass is covered and hermetically sealed at a portion through which the laser beam passes.

A cover 2 is provided on the upper surface of the optical housing 21.
6 are mounted on the LD assembly 22 and the motor hood 25.
Are covered, and a gap 29 is present between the upper surface of the motor hood 25 and the lower surface of the cover 26.

[0005]

In the conventional optical scanning device described above, since the polygon motor is sealed by the motor hood, when the polygon motor rotates, heat generated from the polygon motor is generated inside the motor hood. There is a problem that the temperature inside the motor hood rises and exceeds the upper limit of the usage conditions of the polygon motor.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described drawbacks of the conventional optical scanning device, suppress the temperature rise inside the motor hood, and prevent the optical hood from exceeding the use conditions of the polygon motor. An object of the present invention is to provide a scanning device, and therefore to provide a highly reliable optical scanning device.

[0007]

An optical scanning device according to the present invention comprises:
A polygonal motor having a laser diode assembly having a laser diode of a light emitting source and a collimating lens, a polyhedral reflecting mirror for reflecting a laser beam emitted from the laser diode assembly, and a polygonal motor when the polygonal motor is rotated. An f-θ lens for condensing the laser light reflected by the reflecting mirror on the surface of the photoreceptor was mounted on the optical housing, and the polygon motor was formed of a transparent material in a portion where the laser light passed. In the optical scanning device in which the motor hood is sealed by a motor hood having a transmission window and the cover is placed on the upper surface of the optical housing, the motor hood and the cover are formed of metal and adhered to each other. As a means for bringing the cover into close contact with the cover, use a screw or a double-sided adhesive with good thermal conductivity It is obtained by bonding in-loop.

[0008]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an exploded perspective view showing a first embodiment of the present invention, and FIG. 2 is a sectional view taken along the line AA of the embodiment of FIG.

1 and 2, a laser diode assembly (LD assembly) 2, a polygon motor 3 and an f-.theta. Lens 4 have the same configuration as corresponding components of the conventional optical scanning device shown in FIG. And has an action.

The polygon motor 3 has a transmission window 5a made of a transparent material such as glass in a portion through which a laser beam passes in order to prevent generated noise from leaking outside, as in the conventional example of FIG. The motor hood 5 is covered and hermetically sealed, but the motor hood 5 is formed of a metal having good heat conduction.

A cover 6 made of a metal having good heat conductivity is placed on the upper surface of the optical housing 1.
The polygon motor 3 covering the LD assembly 2 and the motor hood 5 and the f-θ lens 4 are covered. The motor hood 5 and the cover 6 are in close contact with each other, and are connected by screws 7.

In the optical scanning device thus configured, even if the polygon motor 3 rotates and the polygon motor 3 generates heat,
The heat is transmitted from the motor hood 5 to the cover 6 and released to the outside. Therefore, an increase in the temperature inside the motor hood 5 is suppressed, and the upper limit of the use condition of the polygon motor 3 is not exceeded.

FIG. 3 is an exploded perspective view showing a second embodiment of the present invention, and FIG. 4 is a sectional view taken along the line BB of the embodiment of FIG.

The present embodiment also has almost the same configuration as the embodiment of FIG.
Is different in the method of connection.

That is, in FIGS. 3 and 4, the laser diode assembly (LD assembly) 12, the polygon motor 13, and the f-θ lens 14 are shown in FIG. 5 (FIG. 1).
Has the same configuration and operation as the corresponding components of the optical scanning device shown in FIG.

The polygon motor 13 is covered and sealed with a motor hood 15 having a transmission window 15a. The motor hood 15 is formed of a metal having good heat conduction. A cover 16 made of a metal having good heat conductivity is mounted, similarly to the optical scanning device of FIG.

The motor hood 15 and the cover 16 are in close contact with each other.
8 is fixed.

The operation of the optical scanning device configured as described above
The effect is the same as the embodiment of FIG.

[0020]

As described above, the optical scanning device of the present invention comprises a motor hood for sealing a polygon motor, and an LD.
The polygon motor covered with the assembly and the motor hood and the cover covering the f-θ lens are formed of a metal having good heat conduction and are closely attached to each other. Since it can be discharged to the outside through the hood and the cover, the rise in the internal temperature of the motor hood is suppressed, and there is an effect that the upper limit of the use condition of the polygon motor is not exceeded. There is an effect that an electrophotographic image forming apparatus can be obtained.

[Brief description of the drawings]

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

FIG. 2 is a sectional view taken along line AA of the embodiment of FIG. 1;

FIG. 3 is an exploded perspective view showing a second embodiment of the present invention.

FIG. 4 is a sectional view taken along line BB of the embodiment of FIG. 3;

FIG. 5 is an exploded perspective view showing an example of a conventional optical scanning device.

FIG. 6 is a sectional view taken along line CC of the example of FIG. 5;

[Explanation of symbols]

 1.11.21 Optical housing 2.12.22 LD assembly 3.13.23 Polygon motor 4.14.24 f-θ lens 5.15.25 Motor hood 5a.15a.25a Transmission window 6.16.26 Cover 7 Screw 18 Double-sided adhesive tape 29 Gap

Claims (3)

[Claims] 1. A polygon motor having a laser diode assembly having a laser diode as a light emitting source and a collimating lens, a polygon mirror having a polyhedral reflecting mirror for reflecting a laser beam emitted from the laser diode assembly, and rotating the polygon motor. Focuses the laser beam reflected by the polyhedral reflecting mirror on the surface of the photoreceptor
-Theta lens is mounted on an optical housing, the polygon motor is sealed with a motor hood having a transmission window formed of a transparent material at a portion where the laser light passes, and a cover is mounted on the upper surface of the optical housing. The optical scanning device according to claim 1, wherein the motor hood and the cover are formed of metal and adhered to each other. 2. The optical scanning device according to claim 1, wherein the motor hood and the cover are fixed with screws. 3. The optical scanning device according to claim 1, wherein the motor hood and the cover are fixed with a double-sided adhesive tape having good thermal conductivity.