JPH01284877A - optical scanning device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for attaching a laser scanning device used in a laser beam printer or the like to a main body, and more specifically relates to a method for attaching a laser scanning device used in a laser beam printer or the like to a main body. It's about how to maintain accuracy and distance.

[Conventional technology]

FIG. 2 shows a typical arrangement of a laser scanning device and a photoreceptor in a laser beam printer. 1
2 is a laser scanning device, and 2 is a photoreceptor. The laser scanning device 1 includes a polygon mirror 3 which is rotationally driven by a motor 4, a condenser/lens 6, 7, a condenser 4, and a condenser lens 6.
It consists of a case 8 that holds a 7. A laser beam 5 emitted from a laser emitter (not shown) is reflected by a polygon mirror 3, and is passed through a condensing lens 6.7 to a photoreceptor 2.
An image is formed at one point P on the photosensitive surface.

Conventionally, in such a system, the photoconductor 2 and laser scanning device 1 were attached to the main body of the laser beam printer by mounting the photoconductor 2 and the laser scanning device 1 on separate mounting bases, and the mounting bases were attached to the frame of the main body. It was customary to have each of them fixed to the frame of the main body or to a mounting part provided on the frame of the main body.

In a standard laser beam printer with a scanning line density of around 300 dpi, such a configuration was able to satisfy sufficient optical performance, but for high-density laser beam printers with a scanning line density of 600 to 800 dpi. When using a laser beam printer, the depth of field of the optical system becomes shallow, so the laser beam 5 The focus of the image shifts from point P in the optical axis direction, making it impossible to obtain high resolution.

[Means and effects for solving the problems] According to the present invention, by attaching the laser scanning device to the main body with the photosensitive surface of the photoconductor as a reference, dimensional errors between the members and eccentricity of the photoconductor as described above can be avoided. can eliminate the influence of

〔Example〕

FIG. 1 is a front sectional view of one embodiment of the present invention, and FIG. 3 is a top view. In the figure, the members labeled with the same numbers as those in FIG. 2 are the same as those in FIG. 2, so a description thereof will be omitted.

The laser scanning device 1 shown in FIGS. 1 and 2 is fixed to an optical bench 9. The laser scanning device 1 shown in FIGS. The optical bench 9 is placed on rotatable rollers 11 provided on a base 13 fixed to the main body frame, and is movable in the direction of the photoreceptor 2. Abutment rollers 10 are provided at both ends of the optical bench 9 on the photoconductor 2 side so as to be rotatable with respect to the optical bench 9, and the rollers 10 are in contact with the photosensitive surface of the photoconductor 2. On the other hand, a wall 9a is provided at the rear of the laser scanning device 1 on the optical bench 9.
It is biased toward the photoreceptor 2 by a compression spring 12 disposed between the base 13 and the base 13 .

As means for regulating the optical bench 9 in the vertical direction in FIG. 1 and in the axial direction of the photoreceptor 2 in FIG. 3, any known regulating means may be used as appropriate.

16 in FIG. 3 is a laser emitter, 17 is a lens,
The laser beam 5 emitted from the laser emitter 16 is
After being deflected by the rotating polygon mirror 3, the photoreceptor 2
The photoreceptor surface is scanned over the range from 5a to 5b, and an image is recorded on the photoreceptor 2.

Now, with the above configuration, the optical bench 9 has the compression spring 1
2, the roller 10 is always positioned so as to strike the photoconductor 2, so only the distance between the contact surface of the roller 1° to the photoconductor 2 and the laser scanning device must be precisely controlled. For example, the distance between the photoreceptor 2 and the laser scanning device 1 can be maintained with high precision. Furthermore, even if the photosensitive surface moves periodically in the optical axis direction of the laser beam 5 due to eccentricity of the photoconductor 2, the rollers 10 follow this movement, and as a result, the distance between the photoconductor 2 and the laser scanning device 1 is reduced. It can always be kept constant.

Reference numerals 143 and 14b in FIG. 1 are release levers. When removing the photoreceptor 2 during maintenance, rotate the release lever from the position 14a to the position 14b by operating an arm (not shown) linked to the release lever, and then move the optical bench 9 engaged with the release lever. By moving the protrusion 15a provided at the lower part to the position 15b, the optical bench 9 is moved to the right against the compression spring 12, and the roller 10 is separated from the photoreceptor 2.

In the above configuration, the rollers 10 are preferably made of a vibration absorbing material such as hard rubber. In order to prevent the vibrations of the drive system of the photoconductor 2 from being transmitted to the laser scanning device 1, and conversely to prevent the vibrations of the motor 4 from being transmitted to the photoconductor 2, there should be a location between the photoconductor 2 and the laser scanning device 1. This is because better quality images can be obtained by providing a mechanism for absorbing vibrations.

In the embodiment described above, the optical bench 9 and the laser scanning device 1 are constructed as separate members, but the optical bench 9 is not provided, the case 8 of the laser scanning device 1 is enlarged, and the roller 10 is installed in the case 8 itself. It is also possible to attach a

〔Effect of the invention〕

As explained above, by positioning the optical bench on which the laser scanning device is mounted or the laser scanning device itself in contact with the photoconductor, the distance between the laser scanning device and the photoconductor can be maintained with high precision. As a result, the laser beam is reliably focused on the photosensitive surface, making it possible to realize a high-resolution printer.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of an embodiment of the present invention, FIG. 2 is a diagram illustrating the arrangement of a laser scanning device and a photoreceptor of a laser beam printer, and FIG. 3 is a top view of FIG. 1. 1 is a laser scanning device 2 is a photoreceptor 9 is an optical bench 10 is an abutting roller 11 is a roller 12 is a compression spring

Claims (1)

[Claims] A photoreceptor on which optical information is recorded on a photoreceptor surface, an optical scanning means for irradiating the optical information onto the photoreceptor, an optical bench on which the optical scanning means is mounted, or an optical stand attached to the optical scanning means itself, and the photoreceptor An optical scanning device comprising: a roller member rotatable in contact with the photoreceptor; and an urging means for pressing the optical bench or the optical scanning means toward the photoreceptor so as to bring the roller into contact with the photoreceptor.