摘要:
A displacement detection device having excellent stability with the lapse of time and suitable for reduction in size and weight includes: a light source for emitting light; polarizing light splitting unit for splitting the light emitted from the light source into two light beams having difference polarized components, radiating the two light beams to an external optical system, and combining the two light beams reflected by the external optical system to generate combined light; a phase plate provided between the light source and the polarizing light splitting unit and adapted for changing the polarization state of the light emitted from the light source and leading the light to the polarizing light splitting unit; light splitting films for splitting the combined light generated by the polarizing light splitting unit into plural light beams; polarizing units for transmitting only a predetermined polarized components of the split combined light beams; and light-receiving elements for photoelectrically converting coherent light beams transmitted through the polarizing units and thus generating an interference signal.
摘要:
The present invention provides a light emitting/receiving composite unit (1) for emitting and receiving lights, which includes a light source (3), an optical splitting unit (4) for splitting returning lights to the composite unit (1) into a plurality of lights, a polarizing unit (5) for increasing and decreasing quantity of lights transmitted therefrom corresponding to polarization state of the returning lights, and an optical receiving unit (6) which has a plurality of photo-detecting elements (6—1 to 6—4) for detecting the lights transmitted through the polarizing unit (5), which are unitedly integrated into one unit. Also, the present invention provides a displacement detection apparatus of grating interference type, which includes thus unitedly integrated composite unit (1), and an external optical system of an objective unit having a reflection type diffraction grating RG, a reflecting unit (R1a, R1b) for reflecting lights from the composite unit (1) to the reflection type diffraction grating RG, a polarizing unit (WP1a, WP1b) for changing polarization state of diffracted lights from the reflection type diffraction grating RG, and a reflecting unit (R2a, R2b) for reflecting lights transmitted through the polarizing unit (WP1a, WP1b) to cause the reflected lights go backward.
摘要:
A vibration detection device includes: a light source emitting a laser beam; an interferometer including a vibrating body and a reflecting body both capable of reflecting the laser beam, a polarizing beam splitter splitting a laser beam emitted from the light source into beams traveling along first and second optical paths, a first ¼ wave plate arranged between the polarizing beam splitter and the vibrating body in the first optical path, and a second ¼ wave plate arranged between the polarizing beam splitter and the reflecting body in the second optical path, the interferometer causing interference between a reflected beam reflected by the vibrating body and a reference beam reflected by the reflecting body to form a interference pattern; and a detection means quantizing the vibration of the vibrating body on the basis of the formed interference pattern to detect the vibration.
摘要:
An information writing device in which the information can be written accurately efficiently and in which variable formats of the disc-shaped recording mediums can be coped with without the necessity of providing master discs from one format of the disc-shaped recording medium to another. A grating interferometer clock scale system is formed by a clock pattern disc 50 having a clock track 52 carrying an optically readable clock pattern 51 and an optical head 60 for optically reading out the clock pattern 51. Clock signals are generated in a clock generator 90, to which is transmitted, via an optical fiber 80, the interference light obtained as an optical output obtained in turn by optically reading out the clock pattern 51 by the optical head 60, based on electrical signals obtained on photoelectrically transducing the optical output. The servo information synchronized with the clock signals is generated by a servo information generating part 93.
摘要:
Disclosed is a displacement measuring apparatus that includes a composite scale having a magnetic pattern and a diffraction grating each aligned in a direction of measuring axis, and a detector head moving in a direction of measuring axis relative to the composite scale. The detector head has a magnetic detection unit detecting a magnetic field exerted by the magnetic pattern to generate first reproduced signals, a light source irradiating the diffraction grating with light, and an optical detection unit detecting the light diffracted by the diffraction grating to generate second reproduced signals. In composite scale, the magnetic pattern and the diffraction grating are arranged such that a pitch of the first reproduced signals is larger than that of the second reproduced signals.
摘要:
A displacement detection device having excellent stability with the lapse of time and suitable for reduction in size and weight includes: a light source for emitting light; polarizing light splitting unit for splitting the light emitted from the light source into two light beams having difference polarized components, radiating the two light beams to an external optical system, and combining the two light beams reflected by the external optical system to generate combined light; a phase plate provided between the light source and the polarizing light splitting unit and adapted for changing the polarization state of the light emitted from the light source and leading the light to the polarizing light splitting unit; light splitting films for splitting the combined light generated by the polarizing light splitting unit into plural light beams; polarizing units for transmitting only a predetermined polarized components of the split combined light beams; and light-receiving elements for photoelectrically converting coherent light beams transmitted through the polarizing units and thus generating an interference signal.
摘要:
Disclosed is a displacement measuring apparatus that includes a composite scale having a magnetic pattern and a diffraction grating each aligned in a direction of measuring axis, and a detector head moving in a direction of measuring axis relative to the composite scale. The detector head has a magnetic detection unit detecting a magnetic field exerted by the magnetic pattern to generate first reproduced signals, a light source irradiating the diffraction grating with light, and an optical detection unit detecting the light diffracted by the diffraction grating to generate second reproduced signals. In composite scale, the magnetic pattern and the diffraction grating are arranged such that a pitch of the first reproduced signals is larger than that of the second reproduced signals.
摘要:
A displacement detection device having excellent stability with the lapse of time and suitable for reduction in size and weight includes: a light source for emitting light; polarizing light splitting unit for splitting the light emitted from the light source into two light beams having difference polarized components, radiating the two light beams to an external optical system, and combining the two light beams reflected by the external optical system to generate combined light; a phase plate provided between the light source and the polarizing light splitting unit and adapted for changing the polarization state of the light emitted from the light source and leading the light to the polarizing light splitting unit; light splitting films for splitting the combined light generated by the polarizing light splitting unit into plural light beams; polarizing units for transmitting only a predetermined polarized components of the split combined light beams; and light-receiving elements for photoelectrically converting coherent light beams transmitted through the polarizing units and thus generating an interference signal.
摘要:
An information writing device in which the information can be written accurately efficiently and in which variable formats of the disc-shaped recording mediums can be coped with without the necessity of providing master discs from one format of the disc-shaped recording medium to another. A grating interferometer clock scale system is formed by a clock pattern disc 50 having a clock track 52 carrying an optically readable clock pattern 51 and an optical head 60 for optically reading out the clock pattern 51. Clock signals are generated in a clock generator 90, to which is transmitted, via an optical fiber 80, the interference light obtained as an optical output obtained in turn by optically reading out the clock pattern 51 by the optical head 60, based on electrical signals obtained on photoelectrically transducing the optical output. The servo information synchronized with the clock signals is generated by a servo information generating part 93.
摘要:
A displacement pickup is provided which includes a displaceable scale (12) having defined therein a first area (12a) where positional information is recorded with a predetermined pitch and a second area (12b) where positional information is recorded with a predetermined pitch different from that in the first area (12a), a first reading system (10) to read the positional information recorded in the first area (12a), a first phase detector (14) to detect a first phase on the basis of the positional information read by the first reading system (10), a second reading system (11) to read the positional information recorded in the second area (12b), a second phase detector (15) to detect a second phase on the basis of the positional information read by the second reading system (11), a phase comparator (16) to make a comparison between the first and second phases, and an origin signal generator (17) to generate an origin signal according to the result of comparison from the phase comparator (16).