JPH081999A - Method and apparatus for optically scanning - Google Patents

Abstract

PURPOSE:To provide a method and an apparatus for optically scanning by improving the miniaturization and portability of the entire apparatus. CONSTITUTION:The apparatus for optically scanning comprises laser light outputting means 2 for outputting a laser light L for forming an electrostatic latent image on a photosensitive drum 1, and a collimator lens 3 for parallelizing the light L to be output from the means 2, wherein the parallel light from the lens 3 is condensed to irradiate the drum 1 via a reflecting mirror 4 fed along the drum 1.

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 incorporated in a printer such as a terminal device of a computer, a facsimile, a hard copy device, etc., and more particularly, it scans a laser beam for forming an electrostatic latent image on a photosensitive drum. Optical scanning method and apparatus therefor.

[0002]

2. Description of the Related Art Conventionally, as an optical scanning device used for obtaining a hard copy on a recording sheet by using a light source, a laser beam is used as a light source as shown in FIG. A general method is to irradiate the mirror 60 and rotate the rotary polygon mirror 60 by a motor to perform scanning.
In FIG. 7, reference numeral 51 indicates a semiconductor laser, reference numeral 52 indicates a collimating lens, and reference numeral 53 indicates a cylinder lens (or a toroidal lens or the like).

As a method for obtaining a hard copy on a recording paper, first, a laser beam modulated and emitted from the semiconductor laser 51 according to image information is emitted from the collimator lens 5.
The light is collimated once by 2 and is reflected by the rotary polygon mirror 60 through the cylinder lens 53, and is optically scanned by the rotating operation of the rotary polygon mirror 60.

Next, the scanned laser light is irradiated onto the photosensitive drum 54 which is condensed and charged by the fθ lenses 61 and 62, and an electrostatic latent image is formed on the photosensitive drum 54. A visible image obtained by causing charged electrostatic toner to act on the electrostatic latent image on the photosensitive drum 54 is transferred onto a recording sheet.

[0005]

However, in the above structure, the width of the optical scanning device (width of the photosensitive drum in the main scanning direction) largely depends on the lens width of the fθ lenses 61 and 62, and the vertical width thereof The (width in the direction perpendicular to the photosensitive drum) largely depends on the size of the rotary polygon mirror 60, the distance from the rotary polygon mirror 60 to the fθ lenses 61 and 62, and the focal length of the fθ lenses 61 and 62. However, it has become inconvenient due to its large size and poor portability.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical scanning method and apparatus capable of improving the disadvantages of the conventional example, and in particular, reducing the size of the apparatus and improving portability.

[0007]

According to the present invention, laser light output means for outputting a laser light for forming an electrostatic latent image on a photosensitive drum, and laser light output from the laser light output means are collimated. A collimator lens is provided, and the parallel light from the collimator lens is reflected by a reflection mirror portion traveling along the photosensitive drum and is condensed on the photosensitive drum. This aims to achieve the above-mentioned object.

[0008]

[Operation] When the entire device operates, the running force urging mechanism 5B
The reflecting mirror portion 4 is moved along the photosensitive drum 1 by being urged by, and at the same time, the photosensitive drum 1 intermittently rotates in synchronization with the switching timing of the traveling of the reflecting mirror portion 4. Further, the laser light L is output from the laser light output means 2 and sent to the reflection mirror section 4 via the collimator lens 3. And
As the reflecting mirror unit 4 travels, the reflected laser light is sequentially focused and emitted toward the photosensitive drum 1. By repeating this, a predetermined electrostatic latent image is formed on the photosensitive drum 1.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

In the embodiment shown in FIGS. 1 to 4, a laser beam output means 2 for outputting a laser beam L for forming an electrostatic latent image on a photosensitive drum 1 and a laser beam output from the laser beam output means 2. Collimating lens 3 for collimating light L
It has and.

Reference numeral 4 denotes a reflection mirror section that travels the parallel light from the collimator lens 3 along the main scanning direction. The laser light L is reflected by the reflection mirror section 4 and is sequentially focused and irradiated on the photosensitive drum 1 as the reflection mirror section 4 moves.

The reflection mirror section 4 is the photosensitive drum 1 described above.
In order to reflect and output the laser light L, the reflecting surface forms the converging concave mirror 4A, and at the same time, is supported by the mirror traveling drive means 5 and is transported along the central axis of the drum-shaped photosensitive member. There is.

As shown in FIG. 3, the mirror traveling drive means 5 is equipped with a mirror traveling guide 5A arranged along the photosensitive drum 1 and a structure capable of traveling along the mirror traveling guide 5A. A driving force urging mechanism 5B that urges a predetermined traveling force at the same speed to the reflection mirror portion 4 is provided.

Of these, the mirror travel guide 5A is formed so that the reflected laser light of the reflection mirror portion 4 scans the central portion of the photosensitive drum 1. Further, the mirror traveling guide 5A is formed in an endless shape as shown in FIG. 4, and is configured so that the central portion of the photosensitive drum 1 can be repeatedly scanned under the same conditions. In FIG. 4, two reflection mirror units 4 are provided.

The laser light output means 2 and the collimator lens 3 are mounted on one end portion (the left end portion in FIG. 1) of the photosensitive drum 1, and a predetermined modulated laser light is continuously sent to the running reflection mirror portion 4. It is like this.

Next, the operation of the above embodiment will be described.

When the entire apparatus operates, the running force urging mechanism 5
The reflection mirror portion 4 is moved in the directions of arrows A and B in FIG. 4 by being urged by B, and at the same time, the photosensitive drum 1 is intermittently rotated in synchronization with the traveling switching timing of the reflection mirror portion 4. Further, the laser light L is output from the laser light output means 2 and sent to the reflection mirror section 4 via the collimator lens 3. Then, as the reflecting mirror portion 4 travels, the reflected laser light is sequentially focused and emitted toward the photosensitive drum 1. By repeating this, a predetermined electrostatic latent image is formed on the photosensitive drum 1.
Formed.

Therefore, according to this embodiment, the laser light L
Since the reflecting mirror section 4 is configured to travel along the optical path of the laser light output means 2 and the collimator lens 3
Can be installed close to the photosensitive drum 1, and therefore, the entire apparatus can be significantly downsized.

5 and 6 show another example of the reflection mirror section 4. Of these, the reflection mirror section 14 shown in FIG. 5 has a configuration including a plane reflection mirror 14A and a converging convex lens 14B mounted on the laser light input side of the plane reflection mirror 14A. Further, the reflection mirror unit 2 shown in FIG.
Reference numeral 4 is a plane reflection mirror 24A and this plane reflection mirror 2
Converging convex lens 24 provided on the laser beam sending side of 4A
It has a configuration including B and.

In this way as well, it is possible to obtain the same function and effect as those of the embodiment of FIG. 1 described above, and it is possible to further shorten the focal lengths of the converging convex lenses 14B and 24B. There is an advantage that the waist can be made thin, and as a result, the spot diameter of the laser light on the photosensitive drum 1 can be easily reduced.

[0021]

As described above, according to the present invention, since the reflecting mirror portion is made to travel along the optical path of the laser beam, it is possible to equip the photosensitive drum with the laser beam output means and the collimating lens. Therefore, it is possible to provide an unprecedented excellent optical scanning method and its apparatus, which can significantly reduce the size of the entire apparatus and can also improve portability at the same time with the reduction in size. it can.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the operation of the reflection mirror section of the embodiment shown in FIG.

FIG. 3 is a plan view showing a relationship between a traveling guide portion for a mirror and a laser beam output means, which is a part of the embodiment shown in FIG.

FIG. 4 is a front view of FIG. 3;

5 is an explanatory diagram showing another example of the reflection mirror section disclosed in FIG. 1. FIG.

FIG. 6 is an explanatory diagram showing still another example of the reflection mirror section disclosed in FIG. 1.

FIG. 7 is an explanatory diagram showing a conventional example.

[Explanation of symbols]

 1 Photosensitive Drum 2 Laser Light Output Means 3 Collimating Lenses 4, 14, 24 Reflection Mirror Section 5 Mirror Driving Drive Means L Laser Light

Claims (3)

[Claims] 1. A collimator, comprising: a laser beam output unit for outputting a laser beam for forming an electrostatic latent image on a photosensitive drum; and a collimator lens for collimating the laser beam output from the laser beam output unit. An optical scanning method characterized in that collimated light from a lens is reflected through a reflection mirror section that runs along a photosensitive drum and is condensed and irradiated onto the photosensitive drum. 2. A collimator, comprising: a laser beam output unit for outputting a laser beam for forming an electrostatic latent image on a photosensitive drum; and a collimator lens for collimating the laser beam output from the laser beam output unit. A reflecting mirror that travels parallel light from a lens along a main scanning direction set corresponding to the photosensitive drum, and a reflecting mirror portion that supports the reflecting mirror portion and that is along the central axis of the photosensitive drum. An optical scanning device comprising: a traveling drive unit for a mirror for traveling. 3. The optical scanning device according to claim 2, wherein the reflection mirror section includes a condenser lens that condenses the parallel light on the photosensitive drum.