JPH09288246A - Optical scanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain temperature rise caused by the heat generation of a deflector driver and to obtain a soundproofing effect by providing an air passing window through which the hermetically sealed space of the deflector by a partitioning member and the outside of a housing communicate. SOLUTION: The partitioning member 10 is provided around the deflector 4 and a passing window 11 for a beam luminous flux is provided on the member 10. Furthermore, a plane parallel transparent plate 12 is provided on the window 11. The air passing window 15 is provided so that air may get in and out between the space housing the deflector 4 and the outside of the housing. When the rotary polygon mirror 5 of the deflector 4 is rotated, an air current is generated and outside air is taken in, so that the temperature of the space housing the deflector 4 is made low and the driver part of the deflector 4 is cooled. When a filter through which only the air passes and which intercepts noise is used as a dustproof filter 17, the noise of the deflector 4 is prevented from being leaked to the outside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital copier,
The present invention relates to an optical scanning device applied to an electrophotographic device such as a laser printer or a laser facsimile.

[0002]

2. Description of the Related Art In a digital type electrophotographic apparatus, a light beam modulated by an image signal is written (optically scanned) on a photosensitive member by a rotating polygon mirror attached to a deflector. There is. In recent years, the demand for a deflector that rotates at high speed has increased with the increase in the density of optical scanning and the increase in print speed of image forming apparatuses.

[0003]

Problems to be solved when the deflector is rotated at a high rotation speed include an increase in noise and an increase in the amount of heat generated by the driver. As a measure against noise, a cover for covering the deflector itself may be provided. However, an increase in the number of parts and an increase in assembling work are not preferable because they increase costs. Regarding the increase in the amount of heat generated by the driver, the increase in the amount of heat inside the housing is not preferable because the optical elements and the housing are being made of resin and the temperature has a great influence on the optical characteristics. Further, a fan or the like is newly provided for cooling (for example, JP-A-1-121814).
This leads to an increase in the size and cost of the optical scanning device.

Therefore, it is an object of the present invention to provide an optical scanning device capable of suppressing a temperature rise due to heat generation of a deflector driver and providing a soundproof effect.

[0005]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an exploded perspective view showing a general configuration of an optical scanning device using a reflective optical element, and FIG. 2 is a longitudinal sectional view of the same as assembled. This optical scanning device includes an optical housing 1, a cover 2, a light source 3, a deflector 4, a rotary polygon mirror 5, optical elements 6 and 6, a first folding mirror 7 and a second folding mirror 7.
The folding mirror 8 is provided. In such a configuration, the light flux emitted from the light source 3 enters the deflector 4, is scanned and deflected by the rotary polygon mirror 5 within a predetermined angle range, and passes through the optical element 6 having the image forming characteristics and the folding mirrors 7 and 8. An image is formed on the photoconductor 9.

FIG. 3 is an exploded perspective view showing a general structure of an optical scanning device using a transmissive optical element, and FIG. 4 is a longitudinal sectional view of the same in an assembled state. In this optical scanning device, the reflected light from the rotary polygon mirror 5 is reflected by the single folding mirror 7 via the optical element 6 and enters the photoconductor.

FIG. 5 is a perspective view of the optical scanning device showing the first embodiment, and FIG. 6 is a transverse plan view of the same. A partition member 10 is provided around the deflector 4, and the partition member 10 is provided with a passage window 11 for the beam of light beam. Passing window 11
Is provided with a transparent plate 12 which is a parallel plate. Further, an air passage window 15 is provided so that air can flow between the space housing the deflector 4 and the outside of the housing. Therefore, when the rotary polygon mirror 5 of the deflector 4 rotates, an air flow is generated and the outside air is taken in, so that the temperature of the space for accommodating the deflector 4 can be lowered and the driver portion of the deflector 4 can be cooled.

Further, by covering the air passage window 15 with a dustproof filter 17, it is possible to prevent dust in the air from entering the space 13 in which the deflector 4 is housed. Furthermore, if the dust filter 17 that allows only air to pass through and blocks sound is used, the sound of the deflector 4 can be prevented from leaking to the outside. If heat-reflecting glass or the like having a heat insulating effect is used for the transparent plate 12 and a heat insulating material (wood, cork, etc.) is used as the material of the partition member 10, heat can be prevented from moving to the optical element 6.

FIG. 7 is a cross-sectional plan view of the optical scanning device showing the second embodiment. In this example, the passage window 15 for air is set to 2
Providing points (15a, 15b) and passing windows 15a, 15b
The dustproof filters 17a and 17b are fitted into the respective parts. Thus, any number of air passage windows 15 can be installed in consideration of the direction of the air flow outside the housing or in the space 13 that houses the deflector 4. Further, the installation place can be installed anywhere as long as it connects the outside of the housing and the space 13 for housing the deflector 4.

FIG. 8 is an exploded perspective view of an optical scanning device showing a third embodiment, and FIG. 9 is a vertical sectional front view of the same. This embodiment is an example in which the upper portion is covered with the cover 2 of the optical housing 1. Although the foam member 19 is provided on the cover 2 so as to fill the gap between the partition member 10 and the cover 2, the foam member 19 may be provided on the partition member 10 side. Further, the foaming member 19 may be omitted if not particularly required.

FIG. 10 is an exploded perspective view of an optical scanning device showing a fourth embodiment, and FIG. 11 is a vertical sectional front view of the same. This embodiment is an example in which a small cover 18 conforming to the shape of the partition member 10 is provided between the optical housing 1 and the partition member 10 in order to enhance the airtightness. Also in this case, the foam member 19 for filling the gap is provided in the small cover 18 as in the third embodiment shown in FIGS. 8 and 9, but it may be provided on the partition member 10 side. It is possible to eliminate it depending on the case. As compared with the third embodiment, the sound insulation can be further improved. Also small cover 1
8. If a heat insulating material is used for the partition member 10 and the transparent plate 12, the heat transferred to the optical element 6 and the like can be reduced, and fluctuations in optical characteristics due to temperature changes can be reduced.

FIG. 12 is an exploded perspective view of the optical scanning device according to the fifth embodiment. In this embodiment, the partition member 1
In this example, 0 is formed integrally with the optical housing 1. It is the same as the above except that the beam passing window 11 and the air passing window 15 are U-shaped.

[0013]

According to the first aspect of the present invention, since the passage window is provided so that the air can flow between the space inside the housing for accommodating the deflector and the outside of the housing, the rotary polygon mirror can be rotated. An air flow is generated, and air can be taken in from outside the housing to cool the driver portion of the deflector.

According to the second aspect of the present invention, by providing a dustproof filter in the air passage window, dust and the like in the air can be attached to the rotary polygon mirror of the deflector and the mirror surface itself can be contaminated. Can be prevented.

According to the third aspect of the invention, since the material of the dustproof filter is made of a material that allows only air to pass through and blocks sound, the sound leaking to the outside of the deflector housing can be reduced. You can

According to the fourth aspect of the present invention, since the heat insulating material is used as the partition member surrounding the deflector, it is possible to prevent heat from being easily transmitted to other optical elements inside the housing.

According to the invention described in claim 5, since the partition member is formed integrally with the housing, the number of parts and the assembling work can be reduced, and the cost can be reduced.

According to the sixth aspect of the present invention, since the heat insulating material is used as the transparent plate of the parallel flat plate fitted in the light beam passage window of the partition plate, heat is hardly transmitted to other optical elements inside the housing. It is possible to

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a general configuration of an optical scanning device using a reflective optical element.

FIG. 2 is a vertical sectional view of the same as the assembled state.

FIG. 3 is an exploded perspective view showing a general configuration of an optical scanning device using a transmissive optical element.

FIG. 4 is a vertical sectional view of the same in an assembled state.

FIG. 5 is a perspective view of the optical scanning device according to the first embodiment of the present invention.

FIG. 6 is a cross-sectional plan view of the same.

FIG. 7 is a cross-sectional plan view of an optical scanning device showing a second embodiment of the present invention.

FIG. 8 is an exploded perspective view of an optical scanning device according to a third embodiment of the present invention.

FIG. 9 is a vertical sectional front view of the same.

FIG. 10 is an exploded perspective view of an optical scanning device showing a fourth embodiment of the present invention.

FIG. 11 is a vertical sectional front view of the same.

FIG. 12 is an exploded perspective view of an optical scanning device showing a fifth embodiment of the present invention.

[Explanation of symbols]

 1 Optical Housing 2 Cover 3 Light Source 3 4 Deflector 5 Rotating Polygonal Mirror 6 Optical Element 7 First Folding Mirror 8 Second Folding Mirror 9 Photoreceptor 10 Partition Member 11 Passing Window 12 Transparent Plate 13 Space 15 Air Passing Window 17 Dustproof Filter 18 Small cover 19 Foam material

Claims (6)

[Claims] 1. A light source that emits a light beam, a deflector that deflects and scans a light beam emitted from the light source, an optical element group that forms an image of a reflected light beam from the deflector on a photosensitive member surface, a light source, a deflector, In an optical scanning device including at least a housing for accommodating an optical element group and a partitioning member provided inside the housing so as to surround the deflector, the sealed space of the deflector by the partitioning member communicates with the outside of the housing. An optical scanning device, characterized in that an air passage window for air is provided. 2. The optical scanning device according to claim 1, wherein the passage window is covered with a dustproof filter. 3. The optical scanning device according to claim 2, wherein the filter has a property of passing only air and blocking sound. 4. The optical scanning device according to claim 1, wherein the partition member is made of a heat insulating material. 5. The optical scanning device according to claim 1, wherein the partition member is formed integrally with the housing. 6. The optical scanning device according to claim 1, wherein the parallel plate transparent plate fitted into the light beam passage window formed in the partition member is made of a heat insulating material.