US 6,888,653 B2Granted

Optical scanning device

AssigneeBrother Kogyo Kabushiki Kaisha

InventorsShoji Yamada, Mitsuyoshi Watanabe

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Abstract

In an optical scanning device 1, a housing 3 has a space 3a in the inside thereof. A floating rotational plate 2 is housed in the space 3a, and is caused to float and to rotate by a magnetic force. The floating rotational plate 2 has an optical deflection layer 6 thereon. A diffraction grating 71 is formed on the optical deflection layer 6 on and around the center axis Z of the floating rotational plate 2. When a beam of light falls incident on the diffraction grating 71 in a direction normal to the surface of the optical deflection layer 6, the diffraction grating 71 diffracts the light in a radius direction of the circular-shaped floating rotational plate 2. The light is transmitted through optical waveguides 20 and 51 to be emitted outside from the housing 3. By rotating the small-sized floating rotational plate 2 at a high speed inside the housing 3, it is possible to scan the light at a high speed and with a high resolution.

Claims23

Dependent claims

An optical scanning device, comprising:

a housing having a wall defining an internal space surrounded thereby;
a rotational plate provided in the internal space of the housing, the rotational plate having a rotational axis, the rotational plate being provided with an optical deflection portion deflecting an incident light beam in a predetermined direction;
and
a driving unit that causes the rotational plate to float in the internal space of the housing and that drives the rotational plate to rotate around its central axis,
wherein the rotational plate has a first surface, the optical deflection portion being provided on the first surface,
wherein the wall of the housing includes a first wall portion, the first wall portion being located at a position confronting the optical deflection portion on the first surface of the rotational plate, at least a part of the first wall portion including a light incident portion that is made from material that allows the light beam to pass therethrough, and
wherein the optical deflection portion receives the light beam, which has passed through the light incident portion and which has fallen incident on the rotational plate in a direction substantially normal to the first surface, the optical deflection portion deflecting the received light beam in at least one predetermined direction along a plane substantially parallel to the first surface.

4 more elements

An optical scanning device, comprising:

a housing having a wall defining an internal space surrounded thereby;
a rotational plate provided in the internal space of the housing, the rotational plate having a rotational axis, the rotational plate being provided with an optical deflection portion deflecting an incident light beam in a predetermined direction;
and
a driving unit that causes the rotational plate to float in the internal space of the housing and that drives the rotational plate to rotate around its central axis, wherein the optical deflection portion includes a diffraction portion diffracting the incident light beam to deflect the incident light beam in the predetermined direction.

1 more element

Dependencies are inferred from the claim text.