JPH04324415A - Optical scanning device - Google Patents

Abstract

PURPOSE:To obtain the device which has good operability in the angle adjustment of a detection mirror by providing the detection mirror with an angle adjusting mechanism and further providing the adjusting mechanism with an overadjustment preventing mechanism. CONSTITUTION:When a mechanism which adjusts the angle of a detection mirror plate 21 by using the rotation of cam sheet metal 20 rotates the cam sheet metal 20 while adjusting the angle of the detection mirror plate 21, an overrotation prevention claw 20C fitted to the cam sheet metal 20 and an overrotation prevention claw 21C fitted to the detection mirror plate 21 collide against each other. The movement is therefore inhibited to eliminate an unstable area and the cam sheet metal 20 has only a stable area and prevents fitting adjustment in the unstable area. Thus, the overrotation prevention claw 20C provided to the cam sheet metal 20 and the overrotation prevention claw 21C provided to the detection mirror plate 21 restrain the rotation range of the cam sheet metal 20 to prevent the fitting adjustment in the unstable area. Consequently, the operability in the assembling operation of the detection mirror is improved, the reliability of the operation is improved, and the detection mirror becomes hard to shift in fixation position even after the assembling operation.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to an optical scanning device used in laser beam printers, laser facsimile machines, copying machines, etc., and in particular, the present invention relates to an optical scanning device that reflects a scanned laser beam toward a horizontal synchronization signal detection position. The present invention relates to a detection mirror mounting device for use in the detection mirror.

0002

2. Description of the Related Art FIG. 7 is a plan view of a conventional well-known optical scanning device. Attach the optical box 2 to the optical board 1 with screws 3 at the four corners.
It is fixed at A laser beam emitted from a light source section 4 consisting of a semiconductor laser unit that emits a beam adjusted in accordance with the recorded signal is imaged by a lens 5 onto a rotating polygon mirror 8 that rotates in the direction of the arrow. The image is deflected and scanned by lens 8, and an image is formed on photosensitive drum 9 by lenses 6 and 7.

The detection mirror 10 reflects the laser beam scanned by the rotating polygon mirror 8 toward the horizontal synchronization signal detection position.
An optical fiber tube 11 with an incident surface attached to the imaging position is provided, and a laser beam carried by the optical fiber tube is converted into an electrical horizontal synchronizing signal by an optical connector 12.

Lenses 5 and 6 for imaging the laser beam
, 7 are pressed and fixed to an elastic member 14 which is fixed to the bracket of the optical box 2 with a screw 13.

Conventionally, the detection mirror of this type of optical scanning device had a component configuration as shown in FIG. 8, and was attached as shown in FIG. That is, the angle 2 of the mirror portion 21b of the plate spring (hereinafter referred to as the detection mirror plate) 21 that is integrated with the detection mirror by using the cam shape 20b provided on the cam sheet metal 20
5 in the direction of the arrow in the figure, the cam plate 20 is fixed to the mounting portion 23b provided on the base 23 at a predetermined angle using screws.

[0006]

However, in the above configuration, there is an unstable region in the cam shape.

In other words, as shown in FIG. 10, the adjustment starts from the minimum point 26, which is the shortest distance from the center of the cam, and then jumps over the maximum point 27, which is the farthest distance from the center, and moves to the minimum point 26a. It is stable. Moreover, the point is also a point existing between 26 and 27. In other words, in the section between 27 and 26a, the cam is very unstable and difficult to adjust, and there is a high possibility that the fixed position of the cam will shift due to a slight external force after the cam is set. For example, the position of the detection mirror plate may shift significantly due to thermal expansion due to ambient temperature. If the position of the detection mirror shifts in this way, horizontal synchronization detection will not work properly.
As a result, fatal problems such as a shift in the writing start point of the image on the photoreceptor or an inability to output the image occur.

[0008]

[Means for Solving the Problems] The present invention provides a configuration in which a detection mirror for reflecting a scanned laser beam toward a horizontal synchronization signal detection section is provided with an angle adjustment mechanism, and the adjustment mechanism is provided with an over-adjustment prevention mechanism. is taking. in particular,
By providing a stopper for preventing over-rotation of the cam sheet metal used for angle adjustment, movement from the maximum point 27 to the minimum point 26a shown in FIG. 10 is prevented. With such a configuration, the rotation of the cam sheet metal can be adjusted within the stable region from the minimum point 26 to the maximum point 27 shown in FIG. Therefore, the work efficiency during the detection mirror assembly work is improved, and the reliability of the work is also improved. Furthermore, the fixed position of the detection mirror is unlikely to shift even after assembly.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 are diagrams for explaining the structure of a first embodiment of an optical scanning device according to the present invention. The overall configuration of the optical scanning device is the same as the configuration explained using FIG. 7, so it will be omitted here, and only the angle adjustment part of the detection mirror that reflects and guides the scanned laser beam toward the horizontal synchronization signal detection section will be explained. explain. In addition, members that are the same as or equivalent to those described in FIG. 8 are given the same reference numerals, and explanations thereof will be omitted.

FIG. 1 shows the component structure, and FIG. 2 shows the assembled state. In the figure, 21 is a detection mirror plate attached to the over-rotation prevention claw 21c, 20 is a cam plate with an over-rotation prevention claw 20c,
23 is a base.

The angle of the detection mirror plate 21 is adjusted using the cam plate 2.
In a mechanism using zero rotation, the detection mirror plate 2
As the cam plate 20 is rotated while adjusting the angle of 1, the over-rotation prevention claw 20c attached to the cam plate 20 collides with the over-rotation prevention claw 21c attached to the detection mirror plate 21, so the rotation from 27 to 28a in FIG. Movement is prohibited and there is no unstable area, resulting in a cam plate metal with only a stable area as shown in FIG. 3, and installation adjustment in the unstable area can be prevented. In this way, the over-rotation prevention pawl 20c provided on the cam sheet metal and the over-rotation prevention pawl 21c provided on the detection mirror plate regulate the rotation range (adjustment range) of the cam sheet metal and prevent installation adjustment in unstable areas. are doing.

FIGS. 4, 5, and 6 are drawings showing other embodiments, with FIG. 4 showing a component configuration and FIGS. 5 and 6 showing an assembled state. In the figure, 21 is a detection mirror plate, 20 is a cam plate, and 23 is a base. A stopper 24 is provided on the base to prevent over-adjustment of the mirror plate.

The angle of the detection mirror plate 21 is adjusted using the cam plate 2.
In order to prevent the cam sheet metal 20 from becoming unstable in the mechanism in which the cam sheet metal 20 is operated at zero, the detection mirror plate 21 collides with the stopper 24 when the cam sheet metal 20 approaches the maximum point as shown in FIG. Since 20 cannot be rotated, the cam plate is made up of only a stable region as shown in FIG. 3, and installation adjustment in the unstable region can be prevented. In this way, the stopper 24 prevents over-adjustment of the angle of the detection mirror plate 21, and the cam plate 20
prevents over-rotation.

[0014]

As explained above, the present invention provides an angle adjustment mechanism for a detection mirror for reflecting a scanned laser beam toward a horizontal synchronization signal detection section, and includes an over-adjustment prevention mechanism in the adjustment mechanism. By providing this, the angle adjustment of the detection mirror and the fixation after adjustment are performed in the stable region. By using the adjustment mechanism in the stable region in this way, the following effects can be obtained.

(1) Work efficiency is improved because there is no need to worry about unstable areas during assembly work.

(2) Since unstable areas are prevented during assembly, the reliability of assembly is improved.

(3) After assembly is completed, the fixed position is unlikely to shift even if subjected to external forces such as thermal expansion.

[0018] The above effects can be obtained without increasing manufacturing costs.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating the configuration of a first embodiment of a detection mirror angle adjustment mechanism of an optical scanning device according to the present invention.

FIG. 2 is a diagram illustrating the configuration of a first embodiment of a detection mirror angle adjustment mechanism of the optical scanning device of the present invention.

FIG. 3 is a diagram illustrating the relationship between the adjustment angle and the amount of eccentricity when the angle adjustment mechanism of the detection mirror is provided with an overadjustment prevention mechanism.

FIG. 4 is a diagram illustrating the configuration of a second embodiment of the angle adjustment mechanism of the detection mirror of the optical scanning device of the present invention.

FIG. 5 is a diagram illustrating the configuration of a second embodiment of the angle adjustment mechanism of the detection mirror of the optical scanning device of the present invention.

FIG. 6 is a diagram illustrating the configuration of a second embodiment of the angle adjustment mechanism of the detection mirror of the optical scanning device of the present invention.

FIG. 7 is a plan view illustrating the overall configuration of the scanning optical device.

FIG. 8 is a diagram illustrating the configuration of a conventional angle adjustment mechanism for a detection mirror.

FIG. 9 is a diagram illustrating the configuration of a conventional angle adjustment mechanism for a detection mirror.

FIG. 10 is a diagram illustrating the relationship between the adjustment angle of the angle adjustment mechanism of the detection mirror and the amount of eccentricity.

[Explanation of symbols] 4 Light source section 8 Rotating polygon mirror 10 Detection mirror 12 Optical connector 20 Cam sheet metal 20c Over-rotation prevention claw 21 Detection mirror plate 21c Over-rotation prevention claw 23 Base

Claims (1)

[Claims] 1. A light source section, a scanning means for scanning a laser beam emitted from the light source section, a detection mirror for reflecting a part of the laser beam scanned by the scanning means, and the reflected laser beam. In an optical scanning device, the detection mirror is provided with an angle adjustment mechanism;
An optical scanning device characterized in that the adjustment mechanism is provided with an over-adjustment prevention mechanism.