Kabushiki Kaisha Yaskawa Denki

Sadatoshi Inoue

Jiro Muraoka

An optical entire-circumference encoder includes a substrate. A light source is disposed on a rotation axis and a first surface of the substrate. A disc, rotatable about the rotation axis, is disposed on a second surface of the substrate. The disc includes first and second rotation tracks each including rotating slits. A light guiding unit radially guides light from the light source toward an entire outer circumference of the disc to the first and second rotation tracks. The light guiding unit includes a first light guiding section and second light guiding sections. The first light guiding section includes a ring-shaped surface directly or indirectly opposed to a rotation track. The first light guiding section radially guides the light out from the ring-shaped surface toward the first rotation track. The second light guiding sections guide part of the radially guided light to the second rotation track.

Optical entire-circumference encoder and motor system

An optical entire-circumference encoder includes a plurality of rotation slits provided to transmit light at an equal pitch radially around a rotation axis as a center in a rotation track. A plurality of fixed slits is provided to transmit light at an equal pitch in a plurality of regions radially around the rotation axis as the center in a fixed track. A plurality of light receivers is disposed in a vicinity of the rotation axis to receive a light guided by the light guide in the regions respectively. The fixed slits in one of the regions and the fixed slits in another region adjacent to the one of the regions among the regions in the fixed track are formed so that a phase difference by which a rotation direction of the rotor is determined occurs between light reception signals of the plurality of light receivers.

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Kitakyushu, Japan

Sadatoshi Inoue