摘要:
An encoder of this invention radiates a light beam (20) onto an optical scale, in which a reflection film is formed on a surface of a relief type diffraction grating (3) formed on one surface of a light-transmission substrate (1), from a surface opposite to the formation surface of the diffraction grating (3), and detects a change in intensity of interference light caused by diffracted light (21, 22) produced by the diffraction grating, thereby measuring a displacement of the optical scale.
摘要:
In the reference-position detection method and apparatus for detecting a reference position of a scale, first and second patterns are disposed on the scale so that respective detection timings shift inversely to each other in response to a deviation in attitude of the scale. The first and second patterns are detected with timings different from each other by corresponding first and second sensors, and the reference position of the scale is determined according to outputs of respective sensors. Hence, even if the attitude of the scale changes from a predetermined attitude due to an inclination of the scale or a deviation in position of the scale, it is possible to exactly detect the reference position of the scale. Accordingly, it becomes also possible to increase the performance of a displacement measuring apparatus.
摘要:
An interferometer for measuring the displacement of a diffraction grating includes a multi-mode semiconductor laser (1) for generating a laser beam; a device (20) for supplying a predetermined current to the laser so that at least five vertical modes occur in an oscillation spectrum of the laser beam generated by the laser at an intensity ratio of at least 0.05; and an optical system (3) for splitting the laser beam generated by the laser into first and second beams. The optical system also directs the first and second beams to the diffraction grating (6) and effects interference between a first diffracted light beam generated by the diffraction of the first beam at the diffraction grating and a second diffracted light beam generated by the diffraction of the second beam at the diffraction grating to produce an interference light beam. Also provided is a photoelectric convertor (13) for converting the interference light beam into an electrical signal.
摘要:
An apparatus for performing an interpolating process of an input periodic signal is made up of: at least one first board in which a partial circuit to perform the interpolating process is formed as a block; and a second board on which a plurality of first boards can be mounted, wherein the number of interpolations of the interpolating process can be selected in accordance with the number of first boards which are mounted on the second board.
摘要:
An interferometer for measuring the displacement of a diffraction grating includes a multi-mode semiconductor laser (1) for generating a laser beam; a device (20) for supplying a predetermined current to the laser so that at least five vertical modes occur in an oscillation spectrum of the laser beam generated by the laser at an intensity ratio of at least 0.05; and an optical system (3) for splitting the laser beam generated by the laser into first and second beams. The optical system also directs the first and second beams to the diffraction grating (6) and effects interference between a first diffracted light beam generated by the diffraction of the first beam at the diffraction grating and a second diffracted light beam generated by the diffraction of the second beam at the diffraction grating to produce an interference light beam. Also provided is a photoelectric convertor (13) for converting the interference light beam into an electrical signal.