POLYGON MIRROR, METHOD FOR MANUFACTURING POLYGON MIRROR, AND REFLECTING MIRROR

• US 20170205544A1
• Filed: 01/12/2017
• Published: 07/20/2017
• Est. Priority Date: 01/15/2016
• Status: Active Grant

• Current Assignee: Brother Kogyo Kabushiki Kaisha (Brother Industries Limited)
• Original Assignee: Brother Kogyo Kabushiki Kaisha (Brother Industries Limited)
• Inventors: Kurita, Masaaki, Hirabayashi, Hirotaka
• Granted Patent: US 10,451,779 B2
• Time in Patent Office: Days
• CPC Class Codes: B29D 11/00596 Mirrors
• CPC Class Codes: B29D 11/00865 Applying coatings; tinting; colouring printing, marking or copying processes B41M; identification in general G09F3/00; producing decorative effects in general B44C; positioning or marking of lenses B24B13/0055
• CPC Class Codes: G02B 5/0808 having a single reflecting layer G02B5/0883, G02B5/0891 take precedence
• CPC Class Codes: G02B 5/09 Multifaceted or polygonal mirrors , e.g. polygonal scanning mirrors; Fresnel mirrors

Abstract

A polygon mirror includes a substrate having a plurality of side surfaces, a first base surface connecting to the plurality of side surfaces, and a second base surface connecting to the plurality of side surfaces, the first base surface and the second base surface facing away from each other. Each side surface has a first region, and a second region adjoining the first region and extending between the first region and at least one edge of the side surface. The substrate is made of plastic, and a reflection coating is formed on the first region and the second region. A surface roughness of the second region of the substrate is greater than a surface roughness of the first region of the substrate. A method for manufacturing such a polygon mirror and an optical reflecting mirror are also provided.

Claims

1. A polygon mirror comprising a substrate having a plurality of side surfaces, a first base surface connecting to the plurality of side surfaces, and a second base surface connecting to the plurality of side surfaces, the first base surface and the second base surface facing away from each other, each side surface having a first region, and a second region adjoining the first region and extending between the first region and at least one edge of the side surface,

wherein the substrate is made of plastic, and a reflection coating is formed on the first region and the second region, and

wherein a surface roughness of the second region of the substrate is greater than a surface roughness of the first region of the substrate.

2. The polygon mirror according to claim 1, wherein the side surface has a first edge along which the side surface connects to the first base surface and, a second edge along which the side surface connects to the second base surface, and

wherein the second region extends entirely along at least one of the first edge and the second edge of the side surface.

3. The polygon mirror according to claim 2, wherein the second region extends on each side of the first region entirely along the first edge and the second edge of the side surface.

4. The polygon mirror according to claim 1, wherein the substrate has a first connecting portion connecting the side surface and the first base surface, and a second connecting portion connecting the side surface and the second base surface,

wherein a radius of curvature of the first connecting portion is greater than a radius of curvature of the second connecting portion, and

wherein the second region extends entirely along a second edge along which the side surface connects to the second base surface.

5. The polygon mirror according to claim 1, wherein an angle made by the side surface and the first base surface is greater than an angle made by the side surface and the second base surface, and

wherein the second region extends entirely along a second edge along which the side surface connects to the second base surface.

6. The polygon mirror according to claim 1, wherein the reflection coating is contiguously formed from the side surface to the first base surface and to the second base surface.

7. The polygon mirror according to claim 1, wherein the second region has a groove extending entirely along the at least one edge of the side surface.

8. The polygon mirror according to claim 1, wherein the surface roughness of the first region is equal to or less than Ra 0.1 μ

m.

9. The polygon mirror according to claim 1, wherein the surface roughness of the second region is equal to or more than Ra 0.5 μ

m.

10. A method for manufacturing a polygon mirror which comprises a substrate having a plurality of side surfaces, a first base surface connecting to the plurality of side surfaces, and a second base surface connecting to the plurality of side surfaces, the first base surface and the second base surface facing away from each other, each side surface having a first region, and a second region adjoining the first region and extending between the first region and at least one edge of the side surface, the method comprising:

a substrate formation step for forming the substrate by injecting plastic into a mold, and

a coating step for forming a reflection coating on the first region and the second region,

wherein the mold has a first region forming surface contoured to form the first region of the substrate to be molded, and a second region forming surface contoured to form the second region of the substrate to be molded, and

wherein a surface roughness of the second region forming surface is greater than a surface roughness of the first region forming surface.

11. The method according to claim 10, wherein the mold comprises:

a first mold having a plurality of side surface forming surfaces and a first base surface forming surface by which a cavity is formed; and

a second mold having a second base surface forming surface,

wherein the second region forming surface is formed entirely along an edge of each side surface forming surface that connects to the second base surface forming surface.

12. The method according to claim 11, wherein an angle made by the side surface forming surface and the first base surface forming surface is greater than an angle made by the side surface forming surface and the second base surface forming surface.

13. The method according to claim 10, wherein the coating step comprises forming a reflection coating made of metal by sputtering on the first region and the second region.

14. An optical reflecting mirror comprising a substrate having a first surface, and a second surface connecting to the first surface at an angle made with the first surface, the first surface having a first region, and a second region adjoining the first region and extending between the first region and at least one edge of the first surface,

wherein the substrate is made of plastic, and a reflection coating is formed on the first region and the second region, and

wherein a surface roughness of the second region of the substrate is greater than a surface roughness of the first region of the substrate.