Position detection encoder having plural light receiving and light emitting elements

Abstract

A position detection encoder includes a code plate having a plurality of slots formed therein, a first light emitting element and a first light receiving element disposed on one side of the code plate, and a second light emitting element and a second light receiving element disposed on another side of the code plate. A first light beam emitted from the first light emitting element and received by the second light receiving element passes simultaneously through a same one of the plurality of slits of the code plate as does a second light beam emitted from the second light emitting element and received by the first light emitting element. Detection signals having differing phases are respectively obtained from the first and second light receiving elements.

Dependencies are inferred from the claim text.