DETEKTORSYSTEM MIT EINEM OPTISCHEN ROTIERENDEN KODIERER ZUR FESTSTELLUNG DER VERSCHIEBUNG EINER BEWEGLICHEN VORRICHTUNG

• Main Authors: HIROSE, YUKIMI, FUJIEDA-SHI SHIZUOKA-KEN, JP, ITONAGA, MAKOTO, SEYA-KU YOKOHAMA, JP, KAI, MASAKATSU, SEYA-KU YOKOHAMA, JP, NAKAMURA, NOBUAKI, FUJIEDA-SHI SHIZUKA-KEN, JP
• Format: Patent
• Language: German
• Published: 23.09.1993
• Edition: 5
• Subjects: ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVEREDIN A SINGLE OTHER SUBCLASS; MEASURING; MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR; PHYSICS; TARIFF METERING APPARATUS; TESTING

An optical detection system for detecting a displacement amount of a movable device with an optical encoder movable in accordance with a movement of the movable device. The optical encoder (16) has on a light-reflecting layer a plurality of pits (20) successively strung in a predetermined direction. An optical pickup optically picks up the pit information by irradiating the optical encoder with light beams and receiving reflected light beams from the optical encoder. The optical pickup comprises a light-division device for dividing the light beam from a light-emitting device into three light beams so that the divided three light beams are directed to the pit string (24-27) to apply three light spots to the pit string. The light-division device is adapted to be rotatable with respect to the optical encoder so that a light passing through the three light spots intersects the pit string at a predetermined angle. The reflected light beams due to the outside light spots are respectively incident on two photosensitive elements each generating an electrical signal. The electrical signals from the photosensitive elements are out-of-phase by an amount corresponding to the rotation of the light-division device and fed to a detection circuit to detect information of the movement of the movable device and produce a pit detection signal indicative of the information.