Fanuc Corporation

Akinobu Sakata

Nobuyuki Ootake

A code plate of an optical encoder has a nonplanar incident part on a first major surface for transmitting light emitted from a light emitter to the inside of the code plate, and a planar primary reflection part for fully reflecting the transmitted light. The first major surface is also provided with a code pattern part which extends in a ring shape around the rotation axis at a position different from the incident part to switch transmission/non-transmission of the totally reflected light in accordance with a rotation position of the code plate. The code pattern part has nonplanar exit parts which transmit the totally reflected light, and planar secondary reflection parts which again totally reflect the totally reflected light. The secondary reflection parts and exit parts are alternately arranged in the circumferential direction about the rotation axis.

Reflective type optical encoder

A reflective optical encoder, which is inexpensive and is compact in the axial direction thereof. An encoder has a generally circular code plate fixed to a rotating body such as a rotation shaft of a motor; and a light emitting unit and a light receiving unit which are positioned near a first major surface of the code plate. The code plate is made from a light transmissive resin, and on the first major surface, an incidence portion with a concavo-convex shape and an emission portion with a concavo-convex shape are formed. On a second major surface opposed to the first major surface, a transmission portion formed from a concavo-convex shape and configured to transmit light, and a total reflection portion formed from a flat surface and configured to totally reflect light, are formed, wherein the transmission portion and the total reflection portion constitute a code pattern section.

Reflective optical encoder having resin-made code plate

A transmissive optical encoder includes a light emitting element, a light receiving element, a rotatable disk provided with slits and rotatable together with an object of detection, and an optical waveguide having an inlet facing the light emitting element and an outlet facing the light receiving element. The light emitting element and the light receiving element are arranged on the same side in relation to the rotatable disk. The optical waveguide is fixed independently of rotational movement of the rotatable disk.

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Yamanashi, Japan

Akinobu Sakata