JPH0442250A - Electrophotographic printing device - Google Patents

Abstract

PURPOSE:To secure positional accuracy between an optical unit and a photosensitive unit by directly brining the respective unit into contact with each other at a point becoming a positional reference as the unit. CONSTITUTION:The photosensitive unit 8 consisting by turnably supporting a photosensitive drum is positioned in a main body frame 5 by pins 13 and 14 and fixed by a know. The optical unit 2 is mounted on the unit 8 at three accuracy adjusting parts. Then, the accuracy such as parallelism, torsional degree or height of respective two places of guide member 15 and a frame stay 16, which are provided on the frame 7 of a photosensitive body, with respect to the photosensitive drum is previously provided. On the other hand, the accuracy such as the parallelism, the torsional degree or the height of the respective rotating members 17 - 19 of the optical unit 2 is previously provided. Then, the optical unit 2 is pressed against the photosensitive unit 8 at three points by an energizing member 20. Thus, the positional accuracy between the photosensitive body and laser light is easily secured and printing quality is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an electrophotographic printing apparatus that has a scanning optical system including a mirror motor and the like and achieves high printing position accuracy.

[Background of the invention]

The drawbacks of the prior art will be explained with reference to FIG. An optical unit 2 consisting of a mirror motor 1 etc. is fixed to a main body frame 5 via a stay 3 and a stay 4, and a photosensitive tram 6
A photoreceptor unit 8 consisting of a photoreceptor frame 7 and the like that rotatably supports the photoreceptor unit 8 is fixed to the main body frame via stays 9 and 10. A latent image is written on the photosensitive drum 6 by laser light emitted from the emission light window 11 and transferred to the development transfer paper 12.
Take root. Such a configuration has the following drawbacks. It is difficult to ensure the parallelism of the stays 3, 4, 9, and 10 with high precision, and the latent image is written diagonally with respect to the photosensitive drum 6, resulting in The printed characters are slanted. In order to avoid this problem, methods have been considered to improve the machining accuracy of each stay and main body frame, but this poses another problem of increased cost. Furthermore, a method has been considered in which the lenses in the optical units are adjusted after each unit is assembled into the main body frame, but this requires a lot of time for adjustment.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, ensure positional accuracy between an optical unit and a photoreceptor unit with a simple configuration, and provide compatibility between each unit without adjustment.

[Summary of the invention]

In the present invention, in order to ensure positional accuracy between the photoreceptor unit and the optical unit, it is important to bring each unit into direct contact with each other at a point that serves as a positional reference for the unit, without intervening a stay or the like. In addition, focusing on the fact that with such a configuration, compatibility can be maintained on a unit-by-unit basis by ensuring precision on a unit-by-unit basis, we have decided on the arrangement, structure, and fixing method of the optical unit, photoreceptor unit, etc. This is a devised version of the above.

[Embodiments of the invention]

An embodiment of an electrophotographic printing apparatus according to the present invention will be shown with reference to FIGS. 1 and 2. FIG.

A photosensitive unit 8, which rotatably supports the photosensitive drum 6, is positioned on the main body frame 5 with pins 13 and 14, and fixed with a knob (not shown). The optical unit 2 is mounted on the photoreceptor unit 8 at three precision parts. In the photoconductor unit 8, each of the two guide members 15 and the frame steel 16 provided on the photoconductor frame 7 has accuracy such as parallelism, twist, and height with respect to the photoconductor drum 6 determined in advance. be. On the other hand, in the optical unit 2, each of the rotating member 17, the rotating member 18, and the rotating member 19 has accuracy such as parallelism, torsion, and height with respect to the laser beam. , is pressed against the photoreceptor unit 8 at the three points mentioned above, and has a structure that ensures positional accuracy between the laser beam and the photoreceptor.

From FIG. 2, the rotating members 17 and 18 have a spherical shape and can rotate in all directions, while the guide member 15 has a V-shape, and these two rotating members are guided by a guide member. 15, the structure is such that it is possible to ensure the degree of twist between the laser beam and the photoreceptor, and also ensure the parallelism in the axial direction of the photoreceptor drum.

The photoconductor unit 8 is attached to the main body frame 5 using a rail unit.
It has a structure that allows it to be pulled out, allowing for easy replacement of the photoreceptor. 1 and 2 show a state in which the photoconductor unit is housed in the main body frame and ready for printing, but when the knob (not shown) is loosened and the photoconductor unit 8 is pulled out, the optical unit 2 is moved downward. It hangs down and is held in a state where it abuts against a stopper 21 provided on the main body frame 5. When pulling out photoconductor units 1 to 8, remove optical unit 1-8.
Drawer stopper 22 to prevent 2 from being pulled out together.
is profitable. Furthermore, the positional accuracy in the depth direction between the photoconductor unit 1-8 and the optical unit 2 is as follows.
This is ensured by a spring 23 that presses against the photoreceptor unit 8 and a pressing stopper 24 provided on the photoreceptor frame 7. The pusher 1-24 is designed to push the vicinity of the rotating members 17 and 18 so as not to twist the optical unit 1-2.

〔Effect of the invention〕

As described above, according to the present invention, the positional accuracy between the photoreceptor and the laser beam can be ensured with a simple configuration, the printing quality can be improved, and the compatibility between the photoreceptor unit and the optical unit can be ensured. It is possible to improve performance, maintainability, and assemblability.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of an electrophotographic printing apparatus according to the present invention, FIG. 2 is a cross-sectional view taken along the line II in FIG. 1, and FIG. 3 is a longitudinal cross-sectional view of electrophotographic printing showing a conventional example. In the figure, 2 is an optical unit, 5 is a main body frame, and 6 is an optical unit.
8 is a photosensitive drum, 8 is a photosensitive unit, ]-5 is a guide member, ]7.18, ]9 is a rotating member 20 is a biasing member. Name of patent originator Hitachi Koki Co., Ltd.

Claims (1)

[Claims] 1. A photoconductor unit consisting of a photoconductor and a photoconductor frame supporting the photoconductor, and an optical unit consisting of a scanning system, etc., and the optical unit forms a latent image on the photoconductor. write,
An electrophotographic printing apparatus that performs development and fixing, wherein the photoreceptor unit and the optical unit are in contact at at least three points. 2. Supporting the optical unit on a main body frame so as to be able to move near and far to the photoreceptor, pressing the optical unit against the photoreceptor unit with a biasing member, and moving the optical unit to a positioning portion provided on the photoreceptor frame of the photoreceptor unit. 2. The electrophotographic printing apparatus according to claim 1, wherein a positioning portion provided on a case of the optical unit is pressed. 3. The photoconductor unit has a structure that can be pulled out or stored from the main body frame, and a rotating member that is rotatable at least in the direction in which the photoconductor unit is pulled out is provided in a positioning portion of either the optical unit or the photoconductor unit. 2. The electrophotographic printing apparatus according to claim 1, further comprising a guide member for said rotating member. 4. The optical unit is disposed above the photoconductor unit, and the rotating member is provided near the exit light window of the case and along the pull-out direction of the photoconductor unit,
2. The electrophotographic printing apparatus according to claim 1, wherein the photoreceptor frame corresponding to the rotating member is provided with a V-shaped groove.