JPS6161701A - Method of manufacturing rotary polygonal mirror - Google Patents

Abstract

PURPOSE:To fabricate a polygonal mirror with a high degree of accuracy and to enhance the efficiency of fabrication, by cutting the surface of a base material with the use of a linear diamond cutter with no streak-like cut trace being left thereon. CONSTITUTION:A shank 2 to which a linear diamond cutter 15 is secured, is fixed to a tool holder 7 which is rotated in the direction of the arrow 8 about a rotary shaft 14. Further, a base material 3 to be formed thereon several reflecting surfaces 4 is attached to a spline 5 to which a several surface indexing mechanism 6 is set. One of side surfaces 4 is positioned to a cutting position, and then the tool holder 7 is rotated at a predetermined speed while it is moved in the direction of the arrow 13 at a predetermined speed to cut the surface by a removing margine. The above-mentioned procsess is repeated several time to cut the side surfaces 4 of the base material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a rotating polygon mirror used in a laser scanning optical device or the like.

[Conventional technology]

A rotating polygon mirror that is attached to a laser scanning optical device and used, for example, to change the course of a laser beam and scan the laser beam on a light-receiving surface, is typically a polygon mirror with a regular hexagonal cross section. It is known that the side surfaces of a polygonal prism member are provided as reflective mirror surfaces.

Conventionally, in the manufacture of such a rotating polygon mirror, a predetermined portion 4 of a base material 3 made of a member made of a metal material such as an aluminum alloy and formed into a prismatic shape with a regular polygonal cross section is prepared as shown in FIG. 2(a).
Using a diamond R cutting tool 1 as shown in FIG. , ultra-precision cutting to form a reflective mirror surface, etc.

[Problem that the invention seeks to solve]

However, in the ultra-precision cutting process using this diamond R cutting tool, the surface 10 cut by the process of FIG. 2(d), FIG. 2(b), and the surface 10 of FIG. 2
As shown in the plan view of the surface 11 cut by the process in FIG. There were problems such as the light reducing the reflection efficiency of the reflecting mirror surface.

In addition, in order to give the reflective mirror surface a predetermined surface roughness, it is necessary to lower the feed rate of the cutting tool within the processing surface to a certain extent, resulting in a problem of long cutting time and low processing efficiency.

An object of the present invention is to provide a rotary multi-face that can cut the base material surface without leaving cutting marks on the cut surface and improve machining efficiency in the process of ultra-precision cutting of the base material surface. The purpose of this invention is to provide a method for manufacturing a mirror.

[Means to solve problems]

The above objects can be achieved by the following invention.

That is, the method for manufacturing a rotating polygon mirror of the present invention includes the step of forming a reflecting mirror surface by ultra-precision cutting the substrate surface.
It is characterized by precision cutting using a diamond straight blade.

The method of the present invention will be explained in more detail below using one drawing.

1(a) and 1(b) are a front view and a side view, respectively, of a straight diamond blade used in the method of the present invention, and 15 is a straight diamond blade having a straight edge portion. It is a straight blade and is fixed by a shank 2. Note that the diamond straight blade used in the method of the present invention is one that has a degree of straightness that can give a predetermined flatness to the cut surface formed after the cutting process.

In the method of the present invention, ultra-precision cutting of the substrate surface is performed using such a diamond straight blade.

That is, as shown in FIG. 1(C), the shank 2 to which the diamond straight blade 15 is fixed is fixed to the tool holder 7, which can be rotated in the direction indicated by 8 around the rotating shaft 14. Then, a base material 3 having a surface forming a large number of reflecting mirror surfaces is attached to a support 5 in which a multi-face indexing mechanism 6 is set. Here, one of the side surfaces 4 of the base material 3
one is moved to the cutting position and stopped there. next,
13 while rotating the tool holder 7 at a predetermined speed.
The cutting tool holder 7 is moved at a predetermined speed in the direction of 13 to apply the diamond straight blade to the surface 4 of the base material to be processed, and then the tool holder 7 is moved at a predetermined speed in the direction of 13 to perform cutting.

Once the predetermined machining allowance has been cut, the movement of the cutting tool holder is stopped, and the cutting tool holder 7 is moved back in the opposite direction of 13, and the indexing mechanism 6 rotates the base material.
The cutting finished surface is moved from the cutting position, the new base material surface to be cut is moved to the cutting position, stopped there, and the above steps are repeated again to perform cutting.

Further, the above steps are repeated according to the number of reflecting mirror surfaces, and the cutting step is completed.

〔Effect of the invention〕

If a reflective mirror surface is formed by ultra-precision cutting using a diamond straight blade as in the method of the present invention, it will be similar to the case when ultra-precision cutting is performed using a conventional diamond l''R cutting tool. 1. It is possible to form a reflective mirror surface without creating cutting marks on the cut surface.
′;Input caused by the warp point;”Reflector 1 due to folding
It is possible to form a reflective mirror surface that does not cause a decrease in force reflection efficiency, and there is no need to feed the tool within the processing surface, unlike when using a conventional diamond tool. It became possible to significantly shorten the time required for cutting and improve machining efficiency.

Hereinafter, the method of the present invention will be explained in more detail using Examples.

Example A surface roughness Rmax was obtained by cutting the surface on which a reflective mirror surface of a regular hexagonal prism-shaped aluminum base material was to be formed with a diamond tool with a blade width of 10 mm and a straight line cut/20.
A mirror surface with a flatness of 75 or less was obtained. Furthermore, since this mirror surface had no cutting marks, no flare occurred. In addition, when forming a rotating polygon mirror with a width of 5 mm by cutting, the speed of 3000 rpm in the case of conventional feeding method processing,
Compared to the case of a feed of 0.01 mm/rev, when using the method of the present invention with a straight blade and taking a machining allowance of 1-/re machining (2.5 mm/rev), the net machining time is approximately 1/rev per surface. 1
0, improving machining efficiency.

[Brief explanation of drawings]

i 1 [ffl (a) is a front view of the diamond straight blade used in the method of the present invention fixed to the bite shank;
Figure 1(b) is a side view of the diamond straight blade used in the method of the invention fixed to the bit shank, and Figure 1(c)
) is a schematic diagram of a device for explaining the ultra-precision cutting process in the method of the present invention, FIG. 2(a) is a front view and side view of a diamond straight blade, FIG. 2(b) and Figure 2 (C
) is a schematic diagram of an apparatus for explaining the ultra-precision cutting process in the conventional method, and FIGS. 2(d) and 2(e) are schematic diagrams of the cut surface cut by the conventional method. . 1. Diamond R Nohite 2: / Hate Shank 3: Base material 4, Cutting surface 5/Holder 6: Multi-face indexing mechanism 7: Tool holder 8: Rotation direction 9.13: Movement direction 10.11: Cutting surface 12: Screw 14: Rotating shaft 15: Diamond straight blade (a) (b) Fig. 1 (a) (b) (c) Mu (d) (e) Fig. 2

Claims (1)

[Claims] 1) In a method for manufacturing a rotating polygon mirror including a step of forming a reflecting mirror surface by ultra-precision cutting the base material surface, the ultra-precision cutting of the base material surface is performed using a diamond straight blade. A manufacturing method for a rotating polygon mirror.