POLYGONAL MIRROR, DEFLECTOR,OPTICAL SCANNING APPARATUS AND IMAGE FORMING APPARATUS

• US 20190322023A1
• Filed: 04/17/2019
• Published: 10/24/2019
• Est. Priority Date: 04/24/2018
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Matsushita, Naoki, Takata, Atsushi, Tanaka, Yoshihiko, Tanaka, Takatoshi, Yamaya, Fumihiko, Ohta, Mitsuhiro, Katayama, Hiroki
• Granted Patent: US 11,366,310 B2
• Time in Patent Office: Days
• CPC Class Codes: B29C 2045/0027 Gate or gate mark locations
• CPC Class Codes: B29C 45/0025 Preventing defects on the moulded article, e.g. weld lines, shrinkage marks preventing defects on the preformed parts or layers B29C45/14836
• CPC Class Codes: B29C 45/14 incorporating preformed parts or layers, e.g. injection moulding around inserts or for coating articles B29C45/1671 takes precedence
• CPC Class Codes: B29C 45/2602 Mould construction elements
• CPC Class Codes: B29D 11/00596 Mirrors
• CPC Class Codes: B29L 2011/0058 Mirrors
• CPC Class Codes: G02B 26/12 using multifaceted mirrors
• CPC Class Codes: G02B 26/121 Mechanical drive devices for polygonal mirrors
• CPC Class Codes: G02B 5/09 Multifaceted or polygonal mirrors , e.g. polygonal scanning mirrors; Fresnel mirrors
• CPC Class Codes: G03G 15/04036 Details of illuminating systems, e.g. lamps, reflectors lamp housings for copying cameras, reflex exposure lighting G03B27/542
• CPC Class Codes: G03G 15/0409 Details of projection optics for projection printing apparatus G03B27/522
• CPC Class Codes: G03G 15/0435 by introducing an optical element in the optical path, e.g. a filter

Abstract

A polygonal mirror includes reflecting surfaces, a molded member including a first surface and a second surface, a contact portion, and gate marks. Each of said first surface and said second surface has a polygonal shape. The contact portion and the gate marks are formed at non-overlapping positions with a line segment connecting a vertex of the polygonal shape with a rotation center. The gate marks and the reflecting surfaces are the same in number. A perpendicular bisector of a line segment connecting centers of the gate marks adjacent to each other with respect to a rotational direction of the polygonal mirror is formed at a position passing through an associated vertex of the polygonal shape and the rotation center.

Claims

1. A polygonal mirror comprising:

a plurality of reflecting surfaces capable of reflecting laser light emitted from a light source;

a molded member molded with a resin material and including a plurality of side surfaces corresponding to said reflecting surfaces, a first surface crossing said side surfaces, and a second surface which crosses said side surfaces and which is provided on a side opposite from said first surface;

a contact portion formed on said first surface so as to project in an to axial direction passing through a rotation center of said polygonal mirror and configured to contact a rotatable member rotatable about the rotation center of said polygonal mirror; and

gate marks on said first surface or said second surface being traces of injection of the resin material,

wherein each of said first surface and said second surface has a polygonal shape which has a center as a rotation center of said polygonal mirror and which has a plurality of vertexes each comprising a boundary portion between adjacent side surfaces,

wherein said contact portion and said gate marks are formed at non-overlapping positions with a line segment connecting the vertex of the polygonal shape with the rotation center,

wherein said gate marks and said reflecting surfaces are the same in number, and

wherein a perpendicular bisector of a line segment connecting centers of said gate marks adjacent to each other with respect to a rotational direction of said polygonal mirror is formed at a position passing through an associated vertex of the polygonal shape and the rotation center.

2. A polygonal mirror according to claim 1, wherein said contact portion is formed at a plurality of positions which are rotation symmetry about the rotation center of said polygonal mirror.

3. A polygonal mirror according to claim 1, wherein said gate marks are formed on said second surface on a side opposite from said first surface on which said contact portion is formed, and

wherein said contact portion and an associated one of said gate marks formed on said second surface overlap with each other when viewed in an axial direction passing through the rotation center of said polygonal mirror.

4. A polygonal mirror according to claim 1, wherein said gate marks are formed on said first surface on which said contact portion is formed, and

wherein said contact portion is formed at a position where said contact portion does not overlap with said gate marks.

5. A polygonal mirror according to claim 4, wherein said contact portion is formed between an associated one of said gate marks and the rotation center of said polygonal mirror.

6. A polygonal mirror according to claim 4, wherein said contact portion is formed concentrically with an associated one of said gate marks about the rotation center of said polygonal mirror.

7. A polygonal mirror according to claim 1, further comprising a base material made of a metal material inside said molded member molded with the resin material.

8. A polygonal mirror according to claim 1, further comprising a metal layers on said side surfaces.

9. A polygonal mirror according to claim 8, further comprising a protective layer provided on said metal layer and configured to protect said metal layer.

11. A polygonal mirror according to claim 1, wherein said gate marks are formed in the same number as said side surfaces.

12. A deflector comprising:

a polygonal mirror according to claim 1, and

a rotatable member contacting said contact portion formed on said first surface of said polygonal mirror;

wherein a light flux emitted from said light source is subjected to deflection scanning by said reflecting surface of said polygonal mirror through rotation of said polygonal mirror.

14. An optical scanning apparatus comprising:

a light source; and

a deflector according to claim 12,

wherein the light flux emitted from said light source is subjected to deflection scanning on an image bearing member by said deflector.

15. An image forming apparatus comprising:

an optical scanning apparatus according to claim 14,

wherein the image bearing member is scanned with the light flux by said optical scanning apparatus, and an image is formed on a recording material on the basis of an image formed by scanning.

10. A polygonal mirror comprising:

a plurality of reflecting surfaces capable of reflecting laser light emitted from a light source;

a polygonal mirror made of a metal material;

a molded member molded with a resin material outside said base material and including at least a plurality of side surfaces corresponding to said reflecting surfaces and a first surface crossing said side surfaces;

a contact portion formed on said first surface so as to project in an axial direction passing through a rotation center of said polygonal mirror and configured to contact a rotatable member rotatable about the rotation center of said polygonal mirror; and

gate marks on said first surface being traces of injection of the resin material,

wherein said first surface has a polygonal shape which has a center as a rotation center of said polygonal mirror and which has a plurality of vertexes each comprising a boundary portion between adjacent side surfaces,

wherein said contact portion and said gate marks are formed at positions spaced from a line segment connecting the vertex of the polygonal shape with the rotation center, and

wherein a perpendicular bisector of a line segment connecting centers of said gate marks adjacent to each other with respect to a rotational direction of said polygonal mirror is formed at a position passing through an associated vertex of the polygonal shape and the rotation center.

13. A deflector comprising:

a polygonal mirror including,

a plurality of reflecting surfaces capable of reflecting laser light emitted from a light source,

a molded member molded with a resin material and including a plurality of side surfaces corresponding to said reflecting surfaces, a first surface crossing said side surfaces, and a second surface which crosses said side surfaces and which is provided on a side opposite from said first surface, and

gate marks on said first surface or said second surface being traces of injection of the resin material,

wherein each of said first surface and said second surface has a polygonal shape which has a center as a rotation center of said polygonal mirror and which has a plurality of vertexes each comprising a boundary portion between adjacent side surfaces,

wherein said gate marks are formed at non-overlapping positions with a line segment connecting the vertex of the polygonal shape of said first surface with the rotation center, and

wherein a perpendicular bisector of a line segment connecting centers of said gate marks adjacent to each other with respect to a rotational direction of said polygonal mirror is formed at a position passing through an associated vertex of said first surface or said second surface and the rotation center; and

a rotatable member contacting said first surface and rotatable integrally with said polygonal mirror about the rotation center of said polygonal mirror,

wherein said rotatable member is provided with a recessed portion in non-contact with said first surface at a position opposing the light source connecting the vertex of the polygonal shape of said first surface with the rotation center.