JPH09211369A - Deflecting scanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cut off noise generated by a rotating body. SOLUTION: A 1st lid part 31 has a recessed part 32 at the part positioned above a polygon mirror 24. A 2nd lid part 33 covers this recessed part 32 to form a sealed space S. Noise generated by the rotation of the polygon mirror 24 and a scanner motor 25 is attenuated by the lid part 31 first and further attenuated by the space S and 2nd lid part 33 to exit from the deflecting scanner.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection scanning device having a deflection mirror used for deflecting a laser beam in a laser beam printer or the like.

[0002]

2. Description of the Related Art FIG. 6 is a block diagram of an optical system of a typical scanning optical device, in which laser light is emitted from a single point light source of a semiconductor laser light source 1 while diverging but passing through a collimator lens 2. By doing so, the divergent light beam is converted into a parallel light beam. An aperture stop 3 is provided near the collimator lens 2, and the beam spot shape is determined according to the stop shape.

By passing through the cylindrical lens 4, this light beam is converged linearly on the polygon mirror 5 due to the converging action in only one direction. The polygon mirror 5 is fixed to the scanner motor 6 and rotates at high speed in the direction of arrow a. The light beam reflected by the mirror surface a of the polygon mirror 5 is deflected and scanned at high speed as the scanner motor 6 rotates. Further, the light beam has a spherical lens 7 and an fθ lens 8 composed of two or more toric lenses.
To form a minute spot on the photosensitive drum 9.

The light beam L of the image ineffective portion is reflected by the fixed mirror 10 and guided to the timing detection sensor 12 via the condenser lens 11. The optical box 13 houses the elements of these scanning optical devices, and a lid portion (not shown) is attached to the optical box 13 to complete the scanning optical device. A caution label that normally calls attention to the laser light is attached to the lid.

The rotation of the polygon mirror 5 causes the photosensitive drum 9 to perform main scanning in the direction b by the light beam, and the photosensitive drum 9 is driven to rotate around the axis of the cylinder to perform sub-scanning. . In this way, an electrostatic latent image is formed on the surface of the photoconductor, and the recording information corresponding to the luminous flux generated by the semiconductor laser light source 1 is printed on the recording paper. The above is well known as the electrophotographic recording technology.

[0006]

However, in such a deflection scanning apparatus, a demand for a printer having higher definition and higher speed has been increasing in recent years. To cope with this, when the polygon mirror 5 is rotated at a higher speed, there is a problem that noise generated from the scanner motor and the polygon mirror 5 increases.

An object of the present invention is to solve the above-mentioned problems,
An object of the present invention is to provide a deflection scanning device capable of effectively blocking noise.

[0008]

A deflection scanning apparatus according to the present invention for achieving the above object comprises a light source section, a deflector for deflecting a light beam from the light source section by a deflection mirror, and a deflector for deflecting the deflector by the deflector. An optical system that collects the generated light flux on a predetermined surface,
An optical box in which the light source section, the deflector, and the optical system are mounted, and a deflection scanning device in which the first lid section is attached to the optical box,
It is characterized in that a second lid portion is attached on a concave portion formed around the deflector of the first lid portion, and a closed space is formed by the first lid portion and the second lid portion.

[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 a block diagram of a deflection scanning device used in a laser beam printer to scan a photoconductor with a light beam. The deflection scanning device includes an optical box 20, a semiconductor laser light source 21, a collimator lens 22 that makes a light beam generated from the semiconductor laser light source 21 into a parallel light beam, a cylindrical lens 23 that linearly collects the parallel light beam, and a cylindrical lens 23. A polygon mirror 24 having a deflecting / reflecting surface 24a near the line image of the formed light beam, a scanner motor 25 for rotating the polygon mirror 24, an fθ lens 26, and the like are included. The light beam deflected and reflected by the deflecting / reflecting surface 24 a of the polygon mirror 24 enters the reflecting mirror 27 through the fθ lens 26, is reflected by the reflecting mirror 27, and
Irradiate a photoreceptor not shown.

FIG. 2 shows a polygon mirror 24 of the first embodiment.
The cross-sectional view of the circumference of is shown. The portion of the first lid 31 that covers the optical box 20 and that is located above the polygon mirror 24 is a recess 32. The second lid 33 covers the recess 32 and forms a closed space S.

Polygon mirror 24 and scanner motor 2
The noise generated by the rotation of No. 5 is first attenuated by the lid portion 31, and further attenuated by the space S and the second lid portion 33 to reach the outside of the deflection scanning device, so that the first lid portion 31.
The effect of preventing noise is greater than the effect of covering the optical box 20 with only one.

FIG. 3 shows the second embodiment, and the first lid 3
In addition to the recess 32 of the first embodiment, 1 has a recess 34 that forms a substantially cylindrical shape and covers the polygon mirror 24 and the scanner motor 25. The second lid 33 has the recesses 32, 3
4 together to form a sealed space S1, S2.

With such means, the spaces S1 and S2 have a more dampening effect on noise than in the first embodiment, and the wind loss due to the polygon mirror 24 and the scanner motor is reduced and the air is attached to the polygon mirror 24. It is possible to prevent dirt due to dust.

FIG. 4 shows a third embodiment, in which the second lid 3
In item 3, a matter necessary for attention is printed or a bar code for manufacturing control is printed.

A deflection scanning device using a semiconductor laser light source is usually obliged to attach a label to call attention to the laser light. Therefore, according to the third embodiment, the laser light Even if the caution label and the bar code label are not created, the caution and the bar code are simply printed on the second lid portion 33, so that the cost can be reduced.

FIG. 5 shows a fourth embodiment, in which the second lid 3
The material of 3 is an elastic member such as rubber, and the second lid 3
By affixing 3 to the first lid 31, it is possible to improve the effect of attenuating the noise transmitted through the second lid 33, and at the same time, the polygon mirror 24 and the scanner motor 25.
The vibration transmitted from the first lid 31 to the first lid 31 can be attenuated.

[0017]

As described above, according to the deflection scanning device according to the present invention, the second lid portion mounted on the space formed around the deflector of the first lid portion is provided, and the first lid portion is provided. And the second
Forming a sealed space between the lids has an advantage of making it difficult to transmit noise generated from the deflector to the outside.

Further, by forming a part of the first lid part in a cover shape so as to cover the rotating body of the deflector, and forming a sealed space on the upper surface and the side surface of the deflector, the wind of the rotating body is formed. It is possible to reduce loss, prevent contamination, and further reduce noise at the same time.

Furthermore, by printing laser precautions, a bar code and the like on the second lid, noise reduction can be realized without increasing the number of parts as compared with the conventional type.

Further, by setting the natural frequency of the second lid to be lower than the natural frequency of the first lid, further noise reduction and vibration damping can be realized.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a deflection scanning device.

FIG. 2 is a sectional view of the first embodiment.

FIG. 3 is an explanatory diagram of a second embodiment.

FIG. 4 is an explanatory diagram of a third embodiment.

FIG. 5 is an explanatory diagram of the fourth embodiment.

FIG. 6 is a configuration diagram of a conventional example.

[Explanation of symbols]

 20 Optical Box 24 Polygon Mirror 24 25 Scanner Motor 31 First Lid 32, 33 Recess 33 Second Lid S, S1, S2 Space

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[Procedure amendment]

[Submission date] April 22, 1996

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 6

[Correction method] Added

[Correction contents]

FIG. 6

Claims (4)

[Claims] 1. A light source unit, a deflector for deflecting a light beam from the light source unit by a deflection mirror, an optical system for condensing the light beam deflected by the deflector on a predetermined surface, the light source unit and the deflector. An optical box to which the optical system is attached, and a deflection scanning device in which the first lid is attached to the optical box, a second lid is provided on a concave portion formed around the deflector of the first lid. A deflection scanning device, wherein the deflection scanning device is mounted, and a closed space is formed by the first lid portion and the second lid portion. 2. A portion of the first lid portion is formed in a cover shape so as to cover a rotating body of the deflector, and the concave portion is provided on the deflector upper portion and side surface portion of the first lid portion. The deflection scanning device according to Item 1. 3. Laser precautions on the second lid,
The deflection scanning device according to claim 1, wherein a bar code is printed. 4. The deflection scanning device according to claim 1, wherein the material of the second lid portion is lower than the natural frequency of the first lid portion.