JPS6159417A - Rotary polygon mirror and its manufacture - Google Patents

Abstract

PURPOSE:To form the rotary polygon mirror easily at low manufacturing cost by providing a resin film which has a reflecting mirror surface molded by using a specular surface mold on flanks of polygonal shape parts of a base material molded out of aluminum or aluminum alloy material. CONSTITUTION:The base material which is in the shape of, for example, a regular hexagonal prism and has a through hole 4 for installing a rotary polygon mirror coaxial with the center axis of a regular hexagon onto a rotary driving shaft in its center is molded out of aluminum or aluminum alloy. A resin film 2 given surface precision as a reflecting mirror surface 2a molded by a specular surface mold is provided on >=1 flank that the polygonal shape part of the base material 1 has. A film 3 which functions as a reflection enhancing film and/or protection film is provided on the reflecting surface 2a.

Description

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

[Conventional technology]

A rotating polygon mirror is attached to a laser scanning optical device, etc., and is used, for example, to change the course of a laser beam so that the laser beam scans a light receiving surface.Typically, the rotating polygon mirror has, for example, a regular hexagonal cross section. It is known that the side surfaces of a prismatic member made of a regular polygon are formed as reflective mirror surfaces. Conventionally, such a rotating polygon mirror is made by forming an optical glass member into a regular polygonal column through processes such as grinding and polishing.
Furthermore, there is a method of polishing the side surfaces of a prism to form a reflective mirror surface, or cutting a member made of a metal material such as an aluminum alloy into a prism shape with a regular polygonal cross section, and using a diamond cutting tool to form a reflective mirror surface. It has been manufactured by ultra-precision cutting to form a reflective mirror surface.

[Problem that the invention seeks to solve]

However, in manufacturing a rotating polygon mirror by the above method, it is difficult to form a prismatic base material through a process such as cutting from a single optical glass or metal material, and to form a reflective mirror surface with high precision through polishing or cutting treatment. It requires a great deal of labor, time, and advanced technology, and in particular, molding parts other than the reflective mirror surface into a complex shape requires a more complex and advanced process, which raises the problem of high manufacturing costs. Ta.

An object of the present invention is to provide a rotating polygon mirror that can be easily formed at low manufacturing cost and a method for manufacturing the same.

Another object of the present invention is to provide a method that can easily form a rotating polygon mirror whose parts other than the reflecting mirror surface are complicated at a low manufacturing cost.

[Means to solve problems]

The objects described in - can be achieved by the following method of the present invention.

That is, the present invention provides a rotating polygon mirror having a polygonal column-shaped portion provided with a reflective mirror surface on one or more of its side surfaces, and a base material having a polygonal column-shaped portion formed by molding aluminum or an aluminum alloy. and a resin coating provided on one or more -I- side surfaces of the prismatic portion, the surface of which is molded by a mirror mold to form one reflective mirror surface, and a resin coating provided on the reflective mirror surface. A process of forming a rotating polygon mirror characterized by having a film functioning as a reflective film and/or a protective film, and an aluminum or aluminum alloy material into a base material having a polygonal prism-shaped portion by a molding method using a mold. A resin molding material is placed between the base material and a mold having a mirror surface molding surface, and a resin coating is formed on the base material-h by the base material and the mold, and the A process of forming a reflective mirror surface corresponding to the mirror surface of the mold on the resin coating surface, and II functioning as a reflection increasing film and/or a protective film on the reflective mirror surface.
1. A method of manufacturing a rotating polygon mirror, comprising the steps of: providing a ridge;

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the present invention will be described in more detail with reference to the drawings, taking as an example a rotating polygon mirror having a regular hexagonal column shape.

Fig. 1 shows a rotating polygon mirror having a regular hexagonal prism shape, Fig. 1(a) is a perspective view thereof, and Fig. 1(b)
) is a cross-sectional view taken along line A-B in FIG. 1(a).

2 is a base material, which has a regular hexagonal columnar shape, and a through hole 4 is provided in the center thereof for installing a rotating polygon mirror coaxial with the central axis of the regular hexagon on a rotational drive shaft.

This base material 1 is molded by a molding method using a mold using aluminum or an aluminum alloy material.

2 is a resin coating made of resin such as PMMA (polymethyl methacrylate) or epoxy resin, and a portion 2a of the resin coating is provided on the side surface of the polygonal prism.
The surface of the mirror is molded to have the required surface precision as a reflective mirror surface.

Reference numeral 3 denotes a coating that functions as a reflective coating and/or a protective coating, and is provided on a surface formed as a reflective mirror surface of the resin coating surface whose surface has been subjected to cutting treatment.

To manufacture a rotating polygon mirror with such a configuration, first, a base material l having a regular hexagonal columnar shape as shown in FIG. It is molded by a molding method using a mold, such as injection molding.

The material that can be used for forming this base material l is an aluminum material or an aluminum alloy material that can be formed by molding methods such as die casting, compression molding, and injection molding as described above. For A
DGlo, Al070. Aluminum materials and aluminum alloys such as A3081 can be mentioned, and among these, the strength required for the rotating polygon mirror to be formed, the use of the rotating polygon mirror, or the material used as the resin coating described below are important. Select as appropriate depending on matching etc.
It may be used as a material for forming the base material 1.

As described above, in the method of the present invention, die casting using aluminum or aluminum alloy material,
Since the base material 1 is molded by a molding method using a mold such as a pressure molding method or an injection molding method, the base material 1 can be easily formed into a desired shape. Even if the other parts of the base material have a complicated shape, they can be easily formed.

Next, as shown in FIG. 1, a coating made of resin is formed on at least the portion 1a of the base material 1 formed in this way, where the reflective mirror surface will be formed. In the example shown in FIG. 1, the resin coating is also formed on the side and bottom surfaces of the base material 1, and by providing the resin coating on the bottom surface of the base material 1 in this way, the base material It is also possible to increase the hardness or strength of

The resin that can be used to form the coating 2 in the method of the present invention can be used to form a continuous coating on the above-mentioned base material 2 made of aluminum or aluminum alloy material, and by molding with a mold. Any material can be used as long as it can form a reflective mirror surface with high precision on its surface, and for example, the resins mentioned above can be used.

Note that the hardness and strength of the base material 1 can be reinforced by appropriately selecting one from the materials listed in -I- depending on the material constituting the base material 1.

In the method of the present invention, the resin coating 2 is formed by applying the above-mentioned resin coating material 23 to the surface precision required for the reflective mirror surface to be formed, as shown in FIG. 2(a). The molding surface 21 is preferably coated with a mold release agent 22 corresponding to As shown, the base material 1 held by the holder 25 is inserted, and the resin forming material 23 is molded into a predetermined shape by the base material 1 and the molding surface 21 of the mold, and this is cured to form the resin coating 2. This can be done by the following method.

The surface 2a of the resin coating 2 molded in this way is formed by the molding surface 21 of the molding die, and the plane precision of the molding surface 21 of the molding die is transferred, and a highly accurate reflective mirror surface is formed on the resin coating 2. It is formed in a predetermined part of.

In the method of the present invention, finally, on the reflective mirror surface formed as described above, enhancing the reflection function of the reflective mirror surface,
A coating 3 having a function of protecting the reflecting mirror surface is formed, and a rotating polygon mirror as shown in FIG. 1 can be obtained.

For forming the coating 3, A1. Cu, 5i02,
A thin film forming method such as a vapor deposition method or a sputtering method using a material such as MgF2 can be suitably applied.

According to the method of the present invention as described above, wood is molded mainly by a molding method using a mold such as die casting, compression molding, or injection molding using aluminum or aluminum alloy material, and the base material is further molded. A coating made of a resin material is molded onto a predetermined portion of the substrate, and in order to form a reflective mirror surface on the coating surface, a base material is formed by cutting a conventional member made of glass or metal material, and then polished. Unlike the method used to form reflective mirror surfaces, it is possible to form the base material and reflective mirror surface simply and in a short time, and it is also possible to easily mold parts other than the part where the reflective mirror surface is formed into complex shapes. This made it possible to manufacture rotating polygon mirrors at low manufacturing costs.

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

The aluminum material of Example Ancto was formed into a polygonal column shape by die-casting and used as a base material. Thereafter, a clearance of 0.2 to 0.31 was provided between the mirror-finished mold and the base material, which had been finished to the required precision, and an epoxy resin was poured in, cured, and attached to the base material. The base material coated with resin was removed from the mold by a method such as thermal shock.

With this method, the precision of the mirror surface mold is transferred and the surface roughness Rmax
o, 02u or less, a plane eccentric 15 (0,121LI11 or less) surface was completed as a reflective mirror surface on the side surface of the base material.

Furthermore, Cu, 5 is added for the purpose of increasing reflection and protection.
The i07 film was applied by vapor deposition to complete the rotating polygon mirror invented by Wooden.

The rotating polygon mirror of Wooden invention obtained by this manufacturing method has the advantage that the base material itself is cheaper11 (and the base material manufacturing is easier and the diamond mirror cutting process can be omitted) compared to conventional ones. As a result, it was possible to manufacture the product at approximately 50% lower manufacturing cost.

[Brief explanation of the drawing]

FIG. 1 shows an example of a rotating polygon mirror formed by the method of the present invention, FIG. 1(a) is a plan view thereof, and FIG. It is a sectional view taken along a line. Moreover, FIGS. 2(a) and 2(b) are sectional views of the main parts of the mold for explaining the process of molding the resin coating. l, 24: Base material 1a: Side surface 2 metal coating 2a: Reflective mirror surface 3: Coating
4: Through hole 20: Mold 21: Molding part 22: # Mold agent
23: Resin forming material 25: Holder Fig. 1 (a) Fig. 1 (b) No. 1 tooth

Claims (1)

[Scope of Claims] 1) In a rotating polygon mirror having a polygonal column-shaped portion with a reflecting mirror surface on one or more side surfaces, a base having a polygonal column-shaped portion formed by molding aluminum or an aluminum alloy with a mold. a resin coating provided on one or more side surfaces of the prismatic portion, the surface of which is molded with a mirror mold to form a reflective mirror surface, and a resin coating provided on the reflective mirror surface. A rotating polygon mirror comprising a coating that functions as a reflective film and/or a protective film. 2) In a method of manufacturing a rotating polygon mirror having a polygonal prism-shaped portion having a reflective mirror surface on one or more side surfaces,
During the process of molding aluminum or aluminum alloy material into a base material having a polygonal prism-shaped portion by a molding method using a mold, and between the base material and a molding mold having a mirror surface molding surface, a resin molding material is used. arranging a material, forming a resin coating on the base material using the base material and the mold, and forming a reflective mirror surface corresponding to the mirror surface of the mold on the resin coating surface; A reflection-enhancing film and/or
or a step of providing a film functioning as a protective film.