JPS61133920A - Manufacture of rotary polygon mirror - Google Patents

Abstract

PURPOSE:To subdivide and equalize a crystal particle diameter of a mirror surface part, and to improve the characteristics of the mirror surface of a reflection factor and a scattered light intensity, etc. by forming a stepped part on the whole periphery of the vicinity on the outside periphery which becomes the mirror surface part, and performing the shearing and the annealing. CONSTITUTION:A stepped part 2 whose width is narrow is formed by compressing a base material by plastic working, on the whole periphery of the vicinity on the outside periphery which becomes a mirror surface part of a rotary polygon mirror 1. In this compression process, a crystal particle diameter of the base material of the rotary polygon mirror is recrystallized, and subdivided and equalized. That is to say, by forming a stepped shape by the compression, an optimum draft for obtaining a characteristic of a mirror surface of the rotary polygon mirror can be selected. Also, a mirror surface part 3 of the rotary polygon mirror 1 is formed by shearing, a shearing surface of the time of punching by a press generates a plastic flow of a crystal organization by a shearing stress of the time of punching, and becomes small. Thereafter, annealing is performed to the mirror surface part 3, and the crystal particle diameter of the mirror surface part 3 is subdivided and also equalized, and a base material of the rotary polygon mirror can be obtained. In this way, the characteristic of the mirror surface is improved, and the working time of the time of super-precise cutting can be shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a rotating polygon mirror as an optical polarizer used in an optical system such as a laser printer.

Moxibustion yet! Conventionally, in a laser printer, a laser beam emitted from a laser oscillator passes through a reflecting mirror, a modulator, a beam expander, etc., and then is deflected by a rotating polygon mirror attached to a motor and focused by a converging lens to the axis of the photoreceptor. It is designed to be irradiated in the direction.

By the way, the manufacturing method for a rotating polygon mirror attached to a motor is as follows.

That is, first, a round bar made of aluminum alloy is cut, then both end faces are turned and polished, and then,
Milling is performed to form the desired multifaceted shape and a smooth surface is formed to serve as the prohibited surface area, followed by drilling and counterbore processing, followed by strain relief annealing to obtain a rotary multifaceted material. By performing ultra-precision cutting on the smooth surface that will become the mirror surface of the rotating polygon mirror material, a finished rotating polygon mirror can be obtained.

However, the mirror characteristics such as the reflectance and scattered light intensity of the mirror surface of a single-rotation polygon mirror are influenced by the crystal grain size in the crystal FFL weave, and the smooth surface of the rotary polygon R material before ultra-precision cutting is affected. It is desirable that the crystal grain size be finely divided and uniform. This is because if the crystal grain size is finely divided and made uniform, the specular properties after ultra-precision cutting will improve. However, there is a problem in that the trowel surface characteristics are still insufficient for a rotating polygon mirror made of aluminum alloy.

The present invention has been made in view of the problems existing in the prior art described above, and makes it possible to refine and make the crystal grain size of the mirror surface part fine and uniform, thereby improving the surface properties such as reflectance and scattered light intensity. It is an object of the present invention to provide a method for manufacturing a rotating polygon mirror that can improve performance.

1-1 Wind In order to achieve the above object, the present invention provides a method for manufacturing a rotating polygon mirror that has a polygonal shape and is attached to a motor, in which the entire vicinity on the outer periphery, which is the mirror surface of a single-rotation polygon mirror, is At the same time, a stepped portion is formed by compressing the periphery by plastic working, and a mirror surface portion is formed into a desired polygonal shape by shearing, and then annealing is performed to finely divide the crystal grain size of the mirror surface portion. It is characterized in that it obtains a rotating polygon mirror material by making it uniform and uniform.

Man - Shi Issho Hereinafter, one embodiment of the present invention will be described based on the drawings.

In FIGS. 1 to 3, a narrow stepped portion 2 is formed by compressing the base material by plastic working on the entire circumference near the outer periphery of the rotating polygon 'W41, which becomes the mirror surface portion.

This stepped portion 2 will be annealed later, but this compression,
Through the annealing process, the crystal grain size of the base material of the rotating polygon mirror is recrystallized to become finer and more uniform. In this case, it is known that the recrystallized grain size becomes finer as the degree of compression processing increases. That is, by compressing it into a stepped shape, it is possible to select the optimum degree of machining to obtain the mirror characteristics of the mirror surface portion of the rotating polygon mirror.

Furthermore, the mirror surface portion 3 of the rotating polygon mirror l is formed by shearing, and the sheared surface during press punching is crystalline, 1111!, due to the shear stress during punching. causes plastic flow and the crystal grain size becomes finer. That is, since the shear surface of this shear phenomenon is applied to the mirror surface portion of the rotating polygon mirror, the mirror surface characteristics of the mirror surface portion are improved from this surface as well.

Note that if a corner R or a chamfer is provided at the end of the mirror surface part 3 of the rotating polygon mirror 1, it is possible to suppress burrs that occur during ultra-precision cutting, but this corner R is formed during the press punching process. This phenomenon can be used as is (see Figure 3).

Next, the processing steps will be explained using FIGS. 4 to 6. The basic structure of this processing step consists of a first step to a third step. In the first step.

Simultaneously process the motor shaft assembly reference hole 4, the material escape pilot hole 51 for crushing the counterbore portion of the motor assembly screw, and the compressed material escape slit 6 in the stepped portion. Next, in the second step, the first step part 2 is compression molded, the counterbore part 7 is crushed, and the motor shaft assembly reference hole 4 is formed.
Simultaneously process surface chamfering. Furthermore, in the third step, the desired multifaceted shape 8 having the mirror surface portion 3, the mounting hole 9 for the motor assembly screw, and the back chamfering of the motor shaft assembly reference hole 4 are simultaneously processed.

As a result, a rotating polygon mirror material is obtained.

Next, the processing method used in the above steps will be described.

In the first step, since it is sufficient to obtain a simple hole shape, a general press punching method may be used. In the second step, the forging method is preferable because it involves compression molding of the stepped portion and crushing molding of the counterbore portion. In addition, in the third step, a punching method that applies hydrostatic pressure is suitable in order to obtain the surface roughness of the mirror surface, the perpendicularity of the sheared part, and the material hardness.

In addition, the production methods include these single-shot flow production methods and li
[VJ A progressive production method that takes efficiency into consideration may be considered. In the case of a progressive production system, it is necessary to consider equipment that has the required functions for the first to third processes (compound processing that processes the first to third processes simultaneously). Currently considered equipment includes forging presses, opposed die presses,
There are fine blanking presses, etc., but considering constraints such as cutting speed and processing area, fine blanking presses are the most suitable for the conditions.

As mentioned above, in this example, plastic working was applied to all processing in forming the rotating polygon mirror material. The plastic working mold will be explained.

In FIG. 7, 10 is an upper mold, and 11 is a lower mold.

The basic mold construction is a progressive die type using a fixed punch method with fine blanking. Since the die must be processed for crushing and punching at the same time, a die floating method was used to ensure the timing of these operations.
A floating die 12 is provided. Further, in order to obtain a clear shear surface, a hydrostatic pressure generating mechanism is provided. In Fig. 6, 13 indicates a hydrostatic pressure generating ring. In addition, in order to correct the deformation when the motor shaft assembly base hole is crushed,
A vanish bunch 14 is provided on the stage, and the punch is also provided with a chamfering function.

As mentioned above, according to the present invention, the rotating polyhedral jJ! Since the material can be obtained, improvement in specular properties can be achieved. Furthermore, it is possible to shorten the machining time in ultra-precision cutting in the post-process. Furthermore, since conventional cutting is replaced by plastic working, the cost of the rotating polygon mirror can be reduced.

In addition, if the processing to obtain the rotating polygon mirror material is all plastic working as in this example, the processing time can be significantly shortened, and the cost reduction of the rotating polygon mirror can be even more remarkable. .

[Brief explanation of drawings]

FIG. 1 is a plan view of a rotating polygon mirror according to the present invention, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, FIG. 3 is a detailed view of the top of FIG. 2, and FIGS. Fig. 6 shows an embodiment of the present invention, Fig. 4 is a bottom view of the material in the first step, Fig. 5 is a bottom view of the material in the second step, and Fig. 6 is a bottom view of the material in the third step. The bottom view of FIG. 7 is an explanatory view of the mold according to the present invention. ■...Rotating polygon mirror, 2...Stepped part, 3...Rivet surface part, 4...Motor shaft assembly reference hole. 7... Counterbore portion for motor assembly screw, 8... Multifaceted shape, 9... Mounting hole for motor assembly screw, 10... Upper die, 11... Lower die, 12...・
・Floating die, 13... Hydrostatic pressure generation ring. Figure 1 Figure 2 ■ Figure 3

Claims (2)

[Claims] (1) A method for manufacturing a rotating polygon mirror that has a polygonal shape and is attached to a motor, in which a stepped portion is formed by compressing the entire circumference of the outer periphery of the rotating polygon mirror, which will become the mirror surface portion, by plastic working. At the same time, a mirror surface part is formed into a desired polygonal shape by shearing, and then annealing is performed to finely divide and uniformize the crystal grain size of the mirror surface part to obtain a rotating polygon mirror material. A manufacturing method for a rotating polygon mirror. (2) The method for manufacturing a rotating polygon mirror according to claim 1, wherein the motor shaft assembly reference hole, the counterbore for the motor assembly screw, the mounting hole, etc. are also formed by plastic working.