Abstract: An optical displacement sensor comprises a surface emitting laser light source, a scale and a photosensor. The surface emitting laser light source emits a light beam having a predetermined shape. The scale is displaceable in such a manner as to cross the light beam emitted from the surface emitting laser light source and has a diffraction grating of a predetermined period formed thereon for forming a diffraction interference pattern from the light beam. The photosensor receives a predetermined portion of the diffraction interference pattern.

Abstract: An electrostatic encoder comprising receiving coupling electrodes formed on a scale, and extending in a predetermined direction, transmitting coupling electrodes provided on a sensor head, and located to face the receiving coupling electrodes, digital electrodes provided on the scale to extend from the receiving coupling electrodes in a direction perpendicular to the predetermined direction, and arranged at a predetermined pitch, two pairs of interdigital electrodes provided on the sensor head, and located to face the digital electrodes, a voltage applying portion configured to apply an alternating voltage to the transmitting coupling electrodes, and a potential difference detecting portion configured to detect a potential difference between the interdigital electrodes of each of the two pairs of interdigital electrodes.

Abstract: An optical displacement sensor comprises a surface emitting laser light source, a scale and a photosensor. The surface emitting laser light source emits a light beam having a predetermined shape. The scale is displaceable in such a manner as to cross the light beam emitted from the surface emitting laser light source and has a diffraction grating of a predetermined period formed thereon for forming a diffraction interference pattern from the light beam. The photosensor receives a predetermined portion of the diffraction interference pattern.

Abstract: A displacement sensor which detects a positional displacement of a movable member, comprises a position signal generating section configured to generate a periodical signal in accordance with movement of the movable member, a generating section of a signal for detecting a reference position, configured to generate the signal for detecting the reference position, when the movable member is in a predetermined position, a reference position detection circuit configured to detect that the movable member is in a reference position based on the signal for detecting the reference position, generated by the generating section of the signal for detecting the reference position, in synchronization with the periodical signal generated by the position signal generating section, and a selecting section configured to be capable of selecting a phase position to be synchronized from a plurality of phase positions on the periodical signal in the synchronization in the reference position detection circuit.

Abstract: There is disclosed an optical encoder in which a scale can be displaced to cross a first light beam emitted from a first light source, and has a first light modulation region formed of a predetermined-period optical pattern irradiated with the first light beam to generate a diffraction pattern. First photodetector has a light receiving surface for receiving the first light beam transmitted through the first light modulation region of the scale, and has a single or a plurality of light receiving element group formed at a predetermined interval corresponding to the diffraction pattern. A second light modulation region modulates optical properties of the second light beam emitted from a second light source. Second photodetector receives the second light beam whose optical properties are modulated by the second light modulation region.

Abstract: There is disclosed an optical encoder in which a scale can be displaced to cross a first light beam emitted from a first light source, and has a first light modulation region formed of a predetermined-period optical pattern irradiated with the first light beam to generate a diffraction pattern. First photodetector has a light receiving surface for receiving the first light beam transmitted through the first light modulation region of the scale, and has a single or a plurality of light receiving element group formed at a predetermined interval corresponding to the diffraction pattern. A second light modulation region modulates optical properties of the second light beam emitted from a second light source. Second photodetector receives the second light beam whose optical properties are modulated by the second light modulation region.