US 9,851,558 B2Granted

Light deflector

AssigneeBrother Kogyo Kabushiki Kaisha

InventorsKazuhiro Hayakawa, Hidetaka Hoshino, Toshio Sakai, Junji Fujitani, Yasuomi Jibu

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Abstract

A light deflector and an image forming apparatus including the light deflector are provided. The light deflector includes a polygon mirror made of plastic and a motor including a rotor. The rotor supports the polygon mirror and includes a base and a first protrusion protruding from the base toward the polygon mirror in an axial direction. The polygon mirror includes a main body having a plurality of reflecting surfaces, and a second protrusion protruding from the main body toward the base. The second protrusion has an end face and an inner face. The end face is in contact with the base in the axial direction, and the inner face is in contact with the first protrusion in a radial direction.

Claims16

Dependent claims

A light deflector comprising:

a polygon mirror made of plastic;
a motor including a rotor and a shaft, the rotor supporting the polygon mirror, the shaft being coaxially rotatable together with the rotor;
and
a pressing member configured to press the polygon mirror against the rotor, the pressing member including an engaging portion and a pressing portion, the engaging portion being engaged with the shaft, and the pressing portion being in contact with the polygon mirror,
wherein the rotor includes:
a base;
and
a first protrusion protruding from the base toward the polygon mirror in an axial direction,
wherein the polygon mirror includes:
a main body having a plurality of reflecting surfaces and a through hole piercing therethrough in the axial direction, the shaft being disposed in the through hole, the main body having a first inside surface that defines the through hole, the first inside surface extending in the axial direction and separate from the shaft outwardly in the radial direction;
and
a second protrusion protruding from the main body toward the base, the second protrusion being provided around the through hole, the second protrusion having an end face and an inner face, the end face being in contact with the base in the axial direction, and the inner face being in contact with the first protrusion in a radial direction;
wherein a thickness of the second protrusion in the radial direction is smaller than a thickness of the main body in the axial direction,
wherein the end face includes a contact region and a non-contact region, the contact region being in contact with the base, and the non-contact region being out of contact with the base,
wherein a position of the engaging portion in the axial direction is closer to the rotor than a position of a pressing portion in the axial direction.

12 more elements

A light deflector comprising:

a polygon mirror made of plastic;
and
a motor including a rotor and a shaft, the rotor supporting the polygon mirror, the shaft being coaxially rotatable together with the rotor,
wherein the rotor includes:
a base;
and
a first protrusion protruding from the base toward the polygon mirror in an axial direction, and
wherein the polygon mirror includes:
a main body having a plurality of reflecting surfaces and a through hole piercing therethrough in the axial direction, the shaft being disposed in the through hole, the main body having a first inside surface that defines the through hole, the first inside surface extending in the axial direction and separate from the shaft outwardly in the radial direction;
a second protrusion protruding from the main body toward the base, the second protrusion having an end face and an inner face, the end face being in contact with the base in the axial direction, and the inner face being in contact with the first protrusion in a radial direction;
an annular rib protruding form the first inside surface inwardly in the radial direction, the annular rib having a second inside surface extending in the axial direction and separate from the shaft outwardly in the radial direction, such that when viewed from a direction perpendicular to the axial direction, the second inside surface of the rib overlaps the reflecting surfaces;
and
a slope having an inclined surface that connects the second inside surface and the first inside surface, and
wherein an inside diameter of the inner face of the second protrusion is equal to an outside diameter of the first protrusion, and an inside diameter of the second inside surface of the annular rib is smaller than the outside diameter of the first protrusion.

11 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/722,261Filed 27 May 2015
Priority: JP 2014-10972328 May 2014
Published: US 2015/0346485 A13 Dec 2015
Granted: 26 Dec 2017
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

G02B 26/121
Using multifaceted mirrors: mechanical drive devices for polygonal mirrors
B41J 2/471
Using the combination of scanning and modulation of light: using dot sequential main scanning by means of a light deflector, e.g. a rotating…
G02B 7/1821
For mirrors: for rotating or oscillating mirrors
G03G 15/0435
With means for controlling illumination or exposure: by introducing an optical element in the optical path, e.g. a filter