Weight-balanced polygonal mirror, light scanning unit using the polygonal mirror, and image forming apparatus
AssigneeSamsung Electronics Co., Ltd.
InventorsJin-kwon Chun, Jae-hwan Yoo, Won-young Cho, Heon-hee Lim, Ho-hyun Hwang
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Abstract
A polygonal mirror, a light scanning unit using the polygonal mirror, and an image forming apparatus. The polygonal mirror is formed of a plastic and includes a plurality of reflection surfaces that are formed in an outer portion of the polygonal mirror and rotate around a rotational axis, and an internal mirror surface that defines a hole, wherein a ratio of an internal diameter d to an outer diameter D satisfies 0.1≦d/D≦0.3.
Claims20
A polygonal mirror formed of a plastic, the polygonal mirror comprising:
- a plurality of reflection surfaces that are formed on an outer portion of the polygonal mirror and rotate around a rotational axis;
- and
- an internal mirror surface that defines a hole, a ratio of an internal diameter d of the hole to an outer diameter D of the polygonal mirror satisfies 0.1≦d/D≦0.3;
- grooves formed in the internal mirror surface toward the respective corners of the reflection surfaces, the grooves being dimensioned and configured to balance a mass of the polygonal mirror whereby deformation of the polygonal mirror is reduced during rotation.
A light scanning unit comprising:
- a light source to emit a light beam;
- a polygonal mirror to deflect the light beam emitted from the light source, in a main scanning direction;
- and
- an imaging optical system to image the light beam deflected by the polygonal mirror, onto a scanning surface,
- wherein the polygonal mirror is formed of a plastic and comprises
- a plurality of reflection surfaces that are formed in an outer portion of the polygonal mirror and rotate around a rotational axis;
- an internal mirror surface that defines a hole, a ratio of an internal diameter d of the hole to an outer diameter D of the polygonal mirror satisfies 0.1≦d/D≦0.3;
- and
- grooves formed in the internal mirror surface toward the respective corners of the reflection surfaces, the grooves being dimensioned and configured to balance a mass of the polygonal mirror whereby deformation of the polygonal mirror is reduced during rotation.
An image forming apparatus comprising:
- a light scanning unit comprising a light source to emit a light beam;
- a polygonal mirror to deflect the light beam emitted from the light source, in a main scanning direction;
- and an imaging optical system to image the light beam deflected by the polygonal mirror, onto a scanning surface;
- a developing unit comprising a photoconductor that is disposed at an imaging point of the light beam emitted from the light scanning unit, wherein an electrostatic latent image is formed on the photoconductor, and a developing roller that develops the electrostatic latent image formed on the photoconductor;
- and
- a transfer unit onto which an image developed by the developing unit is transferred,
- wherein the polygonal mirror is formed of a plastic and comprises
- a plurality of reflection surfaces that are formed in an outer portion of the polygonal mirror and rotate around a rotational axis;
- an internal mirror surface that defines a hole, a ratio of an of an internal diameter d of the hole to an outer diameter D of the polygonal mirror satisfies 0.1≦d/D≦0.3;
- and
- grooves formed in the internal mirror surface toward the respective corners of the reflection surfaces, the grooves being dimensioned and configured to balance a mass of the polygonal mirror whereby deformation of the polygonal mirror is reduced during rotation.
Dependencies are inferred from the claim text.