Abstract: The scale for a vernier encoder including a sensor relatively movable with the scale in a first direction and configured to read periodic patterns provided in the scale. The scale includes first and second scale tracks each including multiple periodic patterns having mutually different periods in the first direction and being arranged parallel in a second direction. The multiple periodic patterns form, between the first and second scale tracks, multiple pairs of periodic patterns to be used for producing multiple periodic signals, each periodic signal being produced by vernier operation. In at least one of the first and second scale tracks, a first periodic pattern, which is used for producing a shortest period periodic signal among the multiple periodic signals, is provided closest to a boundary between the first and second scale tracks among the multiple periodic patterns.

Abstract: An encoder (100) includes a cylindrical body (10), a sensor unit (7) configured to detect a displacement of the cylindrical body (10) in a circumferential direction of the cylindrical body (10), and a scale (2) that is attached to the cylindrical body (10) using a holder (12) and a holder (13) and that has a signal detection effective region (14) used to detect the displacement by the sensor unit (7), and a region (17) that has a stiffness smaller than a stiffness of the signal detection effective region (14) in the circumferential direction of the cylindrical body (10) is provided on an outside of the signal detection effective region (14) and on at least one side of the first holder (12) and the second holder (13).

Abstract: A scale for a displacement detection apparatus includes a base, and reflection layers formed on the base in a lattice structure, wherein the scale is used as a member displaceable relative to a light-emitting element whose emission wavelength is approximately 1000 nm or less and a light-receiving element receiving the light that is emitted from the light-emitting element and is reflected by the reflection layers, and wherein the base is made of silicon.

Abstract: An encoder includes a scale that includes a pattern row, a detector array, and a signal processor. The pattern row has a plurality of different modulation periods in the moving direction, an amplitude of the energy distribution in the pattern having at least one modulation period being configured to change with a position of the scale in the moving direction. The signal processor acquirers an amplitude of an energy distribution of a corresponding modulation period based on an output signal from the detector array, and an amplitude signal obtained by normalizing a plurality of amplitudes obtained by the plurality of amplitude acquirers, the amplitude signal serving as a position signal representative of the position of the scale.

Abstract: An optical encoder includes a light source, a scale which is irradiated by the light source and has a fine pitch pattern and a coarse pitch pattern in one track, a photo detector array which detects transmitting light or reflected light from the scale which are emitted from the light source, a signal processing unit including a first initial-stage amplifier unit that generates a position detection signal from the photo detector array, and a control unit that uses an output signal from the first initial-stage amplifier unit to control a light amount variation of the light source. The optical encoder can operate in a high resolution detection mode that forms the photo detector array at a first pitch to detect the fine pitch pattern and a low resolution detection mode that forms the photo detector array at a second pitch to detect the coarse pitch pattern.

Abstract: An absolute encoder (100) includes a scale portion (41) movable along with the object and including first and second track (42, 43) having first and second slits (44, 45), a light source (1) that illuminates a light onto the first and second slits, a first detector (9) that detects a first signal obtained from a light from the first slit, a second detector (10) that detects a second signal obtained from a light from the second slit, and a calculator (25, 27) that calculates an absolute position of an object based on the first and second signals. The second slit is formed so that a reflected light intensity or a transmitted light intensity is different in accordance with a position in a moving direction of the scale portion. The calculator obtains an upper-level signal, a middle-level signal, and a lower-level signal to calculate the absolute position.

Abstract: A process for recording information on and reproducing information from a reflection-type holographic information recording medium, having a reflecting layer. Recording includes (i) branching a light beam from a light source into a first branched light beam and a second branched light beam, (ii) forming an information light beam from the first branched light beam by modulation with a spatial light modulation element, and (iii) recording the information by forming an interference fringe by projecting the second branched light beam as a recording reference light beam together with the information light beam onto the recording medium. Reproducing includes projecting a light beam from the light source as a reproducing reference light beam onto the interference fringe. An angle of incidence of the recording reference light beam and an angle of incidence of the reproducing reference light beam into the interference fringe are one hundred eighty degrees from one another.

Abstract: There is provided an optical information recording/reproducing apparatus including a unit for detecting the focus error signal from the reflected light flux from a recording layer of an optical recording medium, and a unit for focusing the light flux on the recording layer of the optical disk on the basis of the focus error signal. In the case of detecting the focus error signal, the light flux of the effective numeric aperture NAeff<1 due to an objective lens and the SIL within a pupil is obtained by a splitting device as the focus error signal, whereby it is possible to suppress the reflected light from the bottom surface of the SIL from being mixed into the focus error signal as a noise.

Abstract: A scale for a displacement detection apparatus includes a base, and reflection layers formed on the base in a lattice structure, wherein the scale is used as a member displaceable relative to a light-emitting element whose emission wavelength is approximately 1000 nm or less and a light-receiving element receiving the light that is emitted from the light-emitting element and is reflected by the reflection layers, and wherein the base is made of silicon.

Abstract: An optical information recording-reproduction process is provide in which a reflection type holographic memory disk is used and light receiving element and other elements are placed on the side of light-projection of the holographic memory disk. Thereby, the apparatus can be made smaller in its thickness.

Abstract: There is provided an optical information recording/reproducing apparatus including a unit for detecting the focus error signal from the reflected light flux from a recording layer of an optical recording medium, and a unit for focusing the light flux on the recording layer of the optical disk on the basis of the focus error signal. In the case of detecting the focus error signal, the light flux of the effective numeric aperture NAeff<1 due to an objective lens and the SIL within a pupil is obtained by a splitting device as the focus error signal, whereby it is possible to suppress the reflected light from the bottom surface of the SIL from being mixed into the focus error signal as a noise.