JPH04161968A - Electrophotograph ic device - Google Patents

Abstract

PURPOSE:To provide possibility of forming an electrostatic latent image accurate ly while the construction is made smaller, by forming a deelectrified surface in the part of a polygonal mirror excluding the scanning surface, controlling the lighting operation of a light source so that this deelectrified surface is irradiated with a laser beam, and leading the beam reflected by the surface to the deelectrifying places on a photo-sensitive body which has undergone the electrostatic latent image processing. CONSTITUTION:A laser beam 25 from a light source 21 is converted into a scanning beam through the scanning surface 13 of a polygonal mirror 11, and an electrostatic latent image is formed on a photo-sensitive body. The lighting operation of this light source 21 is controlled by a deelectrification lighting control means 33 to irradiate the deelectrified surface 14 of the polygonal mirror 11 with laser beam 25, and now the beam 25 reflected by the deelectrified surface 14 is led to the deelectrifying places on the photosensitive body 1 after electrostatic latent image processing through a deelectrifying beam path 41, and the places are deelectrified. Thus an electrostatic latent image can be formed accurately on the photo-sensitive body while the construction is made small.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an electrophotographic apparatus.

Specifically, it applies to electrophotographic devices such as copying machines and laser printers.

[Conventional technology] FIG. 6 shows a schematic configuration of a conventional electrophotographic apparatus.

In the figure, 1 is a photoreceptor that is rotated in the direction of the arrow.

A charger 2 is installed around the photoreceptor 1. Developing device 4° Transfer device 5. A static elimination lamp 6, an optical system 10, etc. are provided.

When printing is performed using this electrophotographic apparatus, the photoreceptor 1 is rotated in the direction of the arrow, and the photoreceptor 1 is uniformly charged by the charger 2. Then, the scanning beam 25a based on the print data is incident on the scanning portion S of the photoreceptor 1 from the optical system IO, and the surface potential of the incident portion is lowered below a predetermined potential. The portion (electrostatic latent image portion) on the photoreceptor 1 whose surface potential has been lowered is developed by the developing device 4 into a toner image, and then transferred onto the paper P by the transfer device 5.

Note that even after the transfer, there are portions on the photoreceptor 1 where the potential is lowered and portions where the potential is not lowered.

Therefore, in preparation for the next charging, the entire photoreceptor 1 is exposed to light at the charge removal location Q of the photoreceptor 1 by the charge removal lamp b, and the surface potential is lowered to a predetermined potential.

By the way, the optical system 10 includes a polygon mirror 11.degree. folding mirror 15. A light source 21 consisting of a laser diode or the like that emits a laser beam 25. It is configured to include scanning lighting control means 32 and the like.

Here, the polygon mirror 11 is moved to the axis 11 by a drive motor (not shown). It is formed to be rotated around a. Further, the polygon mirror 11 is formed into a polyhedral shape, and each side portion 12 of the polygon mirror 11 is formed with a scanning surface for converting the laser beam 25 from the light source 21 into a scanning beam 25a.

Further, the scanning lighting control means 32 is a means for controlling the lighting of the light source 21 based on print data. Specifically, as shown in FIG. 7, the scanning lighting control means 32 detects the reference position of each side portion 12 of the polygon mirror 11 rotated in a predetermined direction using a position detection sensor (not shown) and then waits for a certain period of time. Scanning beam 25 based on print data for a predetermined time after t1 elapses
The lighting of the light source 21 is controlled so that the light a is irradiated from the scanning surface of each side portion 12 toward the scanning location S of the photoreceptor 1.

[Problems to be Solved by the Invention] By the way, in the electrophotographic apparatus described above, due to its configuration, a plurality of static elimination lamps 6 need to be installed in the longitudinal direction of the photoreceptor 1 (direction perpendicular to the plane of FIG. 6). Therefore, a considerable amount of installation space is required.

For example, if the diameter of the photoreceptor 1 is made smaller, the static elimination lamp 6
As a result, a portion other than the neutralization portion Q (for example, a portion of the photoreceptor 1 charged by the charger 2) may be exposed to light, making it difficult to proactively reduce the diameter of the photoreceptor 1.

Therefore, the entire device tends to become large, which is disadvantageous in that it cannot meet the current demand for miniaturization.

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide an electrophotographic apparatus that can form an electrostatic latent image with high accuracy on a photoreceptor while being downsized.

[Means for Solving the Problems] The present invention converts a laser beam from a light source into a scanning beam through a scanning surface of a polygon mirror, forms an electrostatic latent image on a photoreceptor with the scanning beam, In an electrophotographic apparatus configured to eliminate static electricity by irradiating light onto a charged spot on the photoreceptor after latent image processing, a laser beam is applied to a static eliminating surface formed on a portion of the polygon mirror other than the scanning surface. A static elimination lighting control means for controlling the lighting of the light source so as to irradiate the light source, and a static elimination beam guide path for guiding the laser beam reflected from the static elimination surface to a static elimination location on the photoreceptor after electrostatic latent image processing are provided. Features.

[Function] In the present invention, a laser beam from a light source is converted into a scanning beam via a scanning surface of a polygon mirror, and an electrostatic latent image is formed on a photoreceptor with the beam.

In addition, when a laser beam is irradiated onto the static elimination surface of the polygon mirror by controlling the lighting of the light source using the static elimination lighting control means, the laser beam reflected from the static elimination surface is transmitted through the static elimination beam guide after electrostatic latent image processing. The photoreceptor is guided to the static elimination location and the static elimination location is #;.

In this way, by forming the scanning surface and the charge eliminating surface on the polygon mirror, scanning and charge removal of the photoreceptor can be performed with one light source.

As a result, it is possible to form an electrostatic latent image on the photoreceptor with high precision while achieving miniaturization.

[Example] An embodiment of the present invention will be described based on the drawings.

As shown in FIGS. 1 and 2, the electrophotographic apparatus according to this embodiment has a photoreceptor 1. Charger 2. Developing device 4, transfer device 5.
Polygon mirror 11. Light source 21° scanning lighting control means 32
．． It is configured to include a static elimination lighting control means 33 and a static elimination beam guide path 41.

Components that are the same as those shown in FIG. 6 are designated by the same reference numerals, and their explanations will be omitted or simplified.

Here, on each side 12 of the polygon mirror 11, a scanning surface 13 and a charge eliminating surface 14 are formed in a portion other than the scanning surface 13. In this embodiment, the charge eliminating surface 14 is formed on the downstream side of the scanning surface 13 in the rotational direction of the polygon mirror 11 .

The static elimination lighting control means 33 is a means for controlling the lighting of the light source 21 so that each static elimination surface 14 of the polygon mirror 11 is irradiated with the laser beam 25 from the light source 21. In this embodiment, the static electricity removal lighting control means 33 is configured using a part of the function of the drive control device 31 that controls the drive of the entire device.

More specifically, as shown in FIG. 3, the static elimination lighting control means 33 causes the laser beam 25 from the light source 21 to be incident on each static elimination surface 14 for a predetermined period of time after a certain period of time t2 has elapsed after the scanning beam has been irradiated. The configuration is such that the light source 21 is controlled to turn on.

Further, the static elimination beam guide path 41 is a laser beam (static elimination beam) reflected from each static elimination surface 14 of the polygon mirror 11.
In this embodiment, the beam guide path 41 is a means for guiding the beam 25 to the charge removal point Q of the photoreceptor 1 after electrostatic latent image processing. With a reflecting mirror 43 shown.

It is configured to include a device (not shown) for changing the optical path of the beam 25 such as a lens.

Next, the effect will be explained.

Laser beam 25 from light #i21 passes through polygon mirror 1
It is converted into a scanning beam 25a through each scanning surface 13 of 1, and an electrostatic latent image is formed on the photoreceptor 1 by the beam 25a.

Further, when the light source 21 is controlled to turn on using the static elimination lighting control means 33 and the laser beam 25 is irradiated onto the static elimination surface 14 of the polygon mirror 25, the laser beam 25 reflected from the static elimination surface 14 is directed to the static elimination beam guide FI@41. It is guided to the charge removal point Q of the photoreceptor 1 after the ill charge latent image processing, and the charge is removed from the charge removal point Q.

In this manner, by forming the scanning surface 13 and the charge eliminating surface 14 on each side 12 of the polygon mirror 11, scanning and charge removal of the photoreceptor 1 can be performed using one light source (21).

According to this embodiment, the static eliminating lighting control means 32 controls the lighting of the light source 21 so as to irradiate the static eliminating surface 14 formed on the portion of the polygon mirror 11 excluding the scanning surface 13 with the laser beam 25; The laser beam 25 reflected from the surface 14 is removed from the static electricity removal point Q of the photoreceptor 1 after electrostatic latent image processing.
Since the structure includes the charge removal beam guide path 41 that guides the photoreceptor 1, scanning of the photoreceptor 1 and charge removal can be performed using a single light source (21), and the number of parts can be reduced to achieve miniaturization. As a result, it is possible to form an electrostatic latent image on the photoreceptor 1 with high precision while achieving miniaturization.

Note that in the above embodiment, the polygon mirror 11
Although each of the charge eliminating surfaces 14 is formed on the downstream side in the rotational direction of the polygon mirror 11 from each scanning surface 13, it may be provided on the upstream side in the rotational direction or on both the upper and downstream sides.

In addition, each static elimination surface 14 of the polygon mirror 11 is connected to each side portion 12.
However, as shown in FIGS. 4 and 5, each corner 1
6 may be provided. That is, each static elimination surface 14 is formed in each corner 16 to be inclined at a predetermined angle θ with respect to the axis 11a, and to have a curved surface shape. The laser beam 25 reflected from each static elimination surface 14 is guided by a static elimination beam guide path 41 consisting of a lens 45 and the like to a static neutralization location Q of the photoreceptor 1 after electrostatic latent image processing, and static electricity is eliminated from the static neutralization location Q.

Further, the electrostatic latent image formed on the photoconductor 1 is developed by a developing device 4 to form a toner image, and the toner image is transferred onto a sheet of paper by a transfer device 5. It is also possible to adopt a structure in which the image is transferred, and then development, transfer, etc. are performed.

[Effects of the Invention 1] According to the present invention, there is provided a charge removal lighting control means for controlling a light source to irradiate a laser beam to a charge removal surface formed on a portion of a polygon mirror other than a scanning surface; The configuration includes a static elimination beam guide path that guides the laser beam to the static neutralization location on the photoreceptor after electrostatic latent image processing, so it is possible to form an electrostatic latent image with high precision on the photoreceptor while achieving miniaturization. .

[Brief explanation of drawings]

1 to 5 show an embodiment of the present invention. FIG. 1 is a diagram showing the main part, and FIG. 2 is a diagram showing how a photoreceptor is scanned and static electricity removed using one light source. , FIG. 3 is a time chart, FIG. 4 is a perspective view showing the main parts of a modification, and FIG. 5 is a plan view showing the main parts of the modification. 6 and 7 are diagrams showing a conventional electrophotographic apparatus, in which FIG. 6 shows the overall configuration and FIG. 7 is a time chart. DESCRIPTION OF SYMBOLS 1... Photoreceptor, 11... Polygon mirror, 13... Scanning surface of polygon mirror, 14... Discharge surface of polygon mirror, 21... Light source, 41... Discharge beam iii path, Q ...Static charge removal point on the photoconductor.

Claims (1)

[Claims] (1) Converting a laser beam from a light source into a scanning beam via a scanning surface of a polygon mirror, forming an electrostatic latent image on a photoreceptor with the scanning beam, and converting the photoreceptor after electrostatic latent image processing into a scanning beam. In an electrophotographic apparatus configured to eliminate static electricity by irradiating light onto a static neutralization location, static elimination lighting controls lighting of the light source so as to irradiate a laser beam to a static neutralization surface formed in a portion of the polygon mirror other than the scanning surface. An electrophotographic apparatus comprising: a control means; and a charge removal beam guide path that guides a laser beam reflected from the charge removal surface to a charge removal location on the photoreceptor after electrostatic latent image processing.