Patent attributes
An end effector includes: a hand; a substrate holder provided on the hand; a mapping detector provided at distal end portions and of the hand; a light emitter, which the hand is provided with and which is configured to generate detection light; a light receiver, which the hand is provided with and which is configured to receive the detection light and convert the detection light into an electrical output; and an optical path formed such that the detection light emitted from the light emitter passes through the optical path to be incident on the light receiver; the optical path is formed such that detection light is blocked by a substrate detected in a cassette by the mapping detector, and such that detection light is blocked by a substrate held by the substrate holder.