JPH0643371A - Mirror provided with optical correction mechanism - Google Patents

Abstract

PURPOSE:To correct aberration at both terminals of a lens generated in an optical deflector by performing optical correction by fixing a mirror with a mounting metal fitting with width wider than that of a supporting post for mirror mounting, and bending the terminal part of the reflection surface of the mirror by adjusting the mounting of the metal fitting. CONSTITUTION:In the optical deflector which inputs a beam L from a light source 2 to a rotary polygonal mirror 4 and reflects it on the mirror and sets it as incident light to the mirror 10 passing a correction optical system 6. the mirror 10 is arranged so as to bring the reflection surface 10d into contact with a recessed part 14d provided at the upper part of the supporting post 14 for mirror mounting. The mirror 10 is fixed on the upper stage flat part 14a of the supporting post 14 by a cross-section U-shape mounting metal fitting 16 with width wider than that of the supporting post 14. Therefore, it is possible to fix the mirror on the recessed part 14d of the supporting post 14 for mounting with the mounting metal fitting 16 in a state where the terminal part of the reflection surface 10b of the mirror 10 and to change the image-forming position of the beam made incident and reflected on the mirror 10 from an ftheta optical system 6 corresponding to the curved state of the mirror 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mirror having an optical correction mechanism.

[0002]

2. Description of the Related Art Conventionally used mirrors have no optical correction mechanism. Referring to the attached FIG.
The structure of this type of conventional mirror will be described. The beam L emitted from the light source 2 is incident on the mirror surface 4a of the rotary polygon mirror 4,
After being reflected and deflected, the optical path is corrected by passing through the optical system such as the fθ lens 6, the light is reflected to the reflecting surface 10b of the mirror 10, and is reflected on the rotary drum 12 or a flat plate disposed below the mirror 10. An image is formed on an object to be imaged (not shown) or the like. The reflecting surface 10b of the mirror 10 is closely arranged in parallel with the depression 14c between the lower flat portion 14b and the upper flat portion 14a of the depression 14c formed on one side surface of the mirror mounting support column 14. The mounting member 8 bent into an L-shaped cross section includes an upper piece 8a and a lower piece 8b. As described above, the reflection surface 10b of the mirror 10 closely arranged parallel to the recess 14c is attached to the lower piece 8b of the mounting member 8.
Then, the upper piece 8a is fixed to the upper flat portion 14a of the mirror mounting support pillar 14 with a screw 9 to fix the mirror 10 to the mounting bracket 8. The width of the mirror mounting bracket 8 is made narrower than the width of the mounting support pillar 14, and the mirror 10 is sandwiched between the pair of mirror mounting support pillars 14 of the mirror 10 and the pair of mounting brackets 8. The mirror 10 was prevented from bending. In this conventional example, in order to reduce the size, the supporting pillars 14 and the mounting brackets 8 are lightweight and small. Therefore, the mounting brackets 8 are not firmly fixed to the supporting pillars 14. Mirror 1 as it is sandwiched between pillar 14 and mounting bracket 8
Bending the end of the reflective surface 10b of 0 in a desired direction
This is not possible due to the structure, and both members 14 and 8 are mirrors 10.
Used only for pinching, for other purposes eg mirror 1
It was not used for bending the reflecting surface 10b of 0.

[0003]

However, in an optical image forming apparatus that employs an optical system using an fθ lens or the like, the beam shape is set to the entire area in order to correct aberrations that are likely to occur at both ends of the fθ lens optical system. There has been a problem that a perfect image cannot be obtained unless correction or adjustment is made in tandem.

[0004]

In order to solve the above-mentioned problems in the present invention, means for achieving this object will be described with reference to each member by the reference numeral adopted in the embodiment. To do. The beam L from the light source 2 is incident on the rotating polygon mirror 4, is reflected, passes through the correction optical system 6, and is reflected by the mirror 1.
In the optical deflector which is an incident light to 0 and is capable of forming an image on the imaged portion by this reflected light, a vertical wall 14c is provided between the upper flat portion 14a and the lower flat portion 14b. The mirror mounting support column 14 having the recess 14d is provided, the mirror 10 is arranged so that the reflecting surface 10d contacts the recess 14d, and the mirror reflecting surface 10b is pressed against the vertical wall 14c of the recess 14d. With the lower piece 16b of the mounting member 16 bent into an L-shaped cross-section abutting and pressing the upper surface 10a of the mirror 10, the upper piece 16a of the mounting member 16 is screwed by a screw 9 to support the mirror mounting support pillar. Provided is a mirror having an optical correction machine, which is fixed to the upper flat portion 14a of 14 and in which the width of the mounting bracket 16 is formed to be larger than the width of the mirror mounting support column 14.

[0005]

The mirror 10 can be firmly fixed to the mirror mounting support pillar 14 by the mounting bracket 16 so as not to move, so that the mounting support pillar is bent upward or downward at the end of the reflecting surface 10b of the mirror 10. Since it can be fixed to the recess 14d of 14 by a mounting bracket, the image forming position F of the beam incident on and reflected from the mirror 10 from the fθ optical system 6 can be changed appropriately according to the curved state of the mirror 10. You can

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to the accompanying drawings. The same reference numerals as those used in FIG. 2 for explaining the conventional example indicate the same members, and thus detailed description thereof will be omitted. In FIG. 1 illustrating an embodiment of the present invention, the width of the mounting bracket 16 is formed to be larger than the width of the mirror mounting support column 14, and when the mounting bracket 16 is fixed to the mounting support column 14. , The reflecting surface 10b of the mirror 10
It can be fixed to the mounting support column 14 so that the end portion thereof does not move firmly. Therefore, the mirror 10 can be fixed, and the end of the mirror reflection surface 10b can be curved concavely or convexly. Below in FIG.
A curved configuration of the end portion of the reflecting surface 10b of the mirror 10 will be described with reference to FIGS. In FIG. 3, the end portion of the reflecting surface 10b of the mirror 10 is fixed to the mirror mounting support column 14 with a mounting member 16 so as not to form a normal ideal state, that is, a curved portion. Therefore, it is not necessary to correct the optical aberration of the fθ optical system 6 at the image forming position F as shown in FIG. FIG. 4 shows a case where the end of the reflecting surface 10b of the mirror 10 is curved downward, that is, the reflecting surface 10b of the mirror 10 is formed in a convex shape, and is fixed to the mirror-mounting support pillar 14 by the mounting bracket 16. In this case, The convergent light from the fθ optical system 6 is corrected, and its image forming point F ₁ is as shown in FIG. Further, as shown in FIG. 5, the end portion of the reflecting surface 10b of the mirror 10 is curved upward, that is, the reflecting surface 10b of the mirror 10 is formed into a concave shape so that the mounting bracket 1 is attached to the mirror mounting support pillar 14.
In this case, the divergent light from the fθ optical system 6 is corrected, and as a result, the image forming point F ₂ becomes as shown in FIG. Therefore, the image formation position can be corrected according to the position of the image formation object, or the position of the image formation object can be set according to the image formation point.

[0007]

[Effect] Aberrations at both ends of the lens, which occur in the optical deflector employing the fθ lens optical system, can be corrected by bending the ends of the mirror reflecting surface.

[Brief description of drawings]

FIG. 1 is a schematic side view of an optical deflector including a mirror having an optical correction mechanism according to the present invention.

FIG. 2 is a schematic side view of a conventional optical deflector.

FIG. 3 is an explanatory diagram of a state in which the position of the mirror reflecting surface is normally maintained.

FIG. 4 is an explanatory view of a state where the position of the mirror reflecting surface is curved downward and the mirror reflecting surface is formed to be convex.

FIG. 5 is an explanatory diagram of a state in which the position of the mirror reflecting surface is curved upward and the mirror reflecting surface is formed in a concave shape.

FIG. 6 is an explanatory view showing a mirror reflection surface at a normal position and an image forming position of a beam.

FIG. 7 is an explanatory view showing an image forming position when the mirror reflecting surface is formed in a convex or concave shape.

[Explanation of symbols]

 L beam F Imaging point 2 Light source 4 Rotating polygonal mirror 4a Mirror surface 6 fθ Lens correction optical system 9 Screw 10 Mirror 10a Upper surface 10b Reflecting surface 12 Rotating drum (imaging surface) 14 Mirror mounting support pillar 14a Upper flat part 14b Lower flat Part 14c Vertical wall 14d Recess 16 Mounting bracket 16a Upper piece 16b Lower piece

Claims (3)

[Claims] 1. A beam from a light source is incident on a rotating polygonal mirror, reflected and passed through a correction optical system to be incident light on a mirror, and the reflected light forms an image on an image-formed part. In the possible optical deflector, a mirror-mounting support column having an indentation with a vertical wall is provided between the upper flat part and the lower flat part, and the end of the mirror is placed so that the reflective surface comes into contact with the indented part. And the lower surface of the mounting bracket bent to have an L-shaped cross section so as to press the mirror reflection surface against the vertical wall of the recess is brought into contact with the mirror, and the upper surface of the mirror is pressed, and the mounting bracket is mounted. A mirror equipped with an optical correction machine, wherein the upper piece is fixed to the upper flat part of the mirror-supporting support pillar with a screw, and the width of the mounting bracket is formed larger than the width of the mirror-mounting support pillar. 2. A mirror having an optical correction mechanism according to claim 1, wherein an end portion of the mirror reflecting surface is fixed to a mirror mounting support pillar by a mounting bracket so as to be bendable in a predetermined direction. 3. The optical correction mechanism according to claim 1, wherein the mirror reflecting surface is curved convexly to correct the convergent light, or the mirror reflecting surface is curved concavely to correct the divergent light. With a mirror.