Abstract: A driving assistance device includes a recording unit that records vehicle past traveling positions and related position estimation information, and a relative position estimation unit that estimates a vehicle relative position based on a sensor, adds a history of the relative position to the past traveling position, and uses the output of the sensor. The driving assistance device further includes a position estimation unit that estimates a vehicle position with respect to the past traveling positions and adds a history of the estimated position to the past traveling position, in addition to a deviation determination unit that determines deviation from the past traveling positions using a distribution of the past traveling positions, the vehicle position relative to the past traveling positions, and a reference value. The driving assistance device includes a control unit that controls the vehicle to cancel a warning or deviation when the deviation is determined.

Abstract: 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 converti

Abstract: 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 converti

Abstract: 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 converti

Abstract: 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.

Abstract: Signals are recorded as residual polarization in a recording and/or reproducing member, exhibiting ferroelectricity, and the difference in phase, dependent on the direction of residual polarization, of optical harmonics generated on illumination of a reproducing light beam, is detected by phase comparison with optical harmonics generated in a uniformly polarized reference member arranged in an optical path other than the optical path of the recording and/or reproducing member. Since the disclosed technique can use a conventional optical recording and/or reproducing technique, the disclosed technique is high in valuability as a multi-layered medium. The optical recording and/or reproducing layer can be readily implemented as a multi-layer structure to increase the recording capacity appreciably.

Abstract: 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 converti

Abstract: 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.

Abstract: The present invention relates to a magnetic shielding case comprising a structure for improving the uniformity in light receiving sensitivity of a phomultiplier while maintaining sufficient magnetic shielding function, and a light detecting apparatus including this magnetic shielding case. This apparatus comprises a photomultiplier and a magnetic shielding case accommodating the photomultiplier. In particular the magnetic shielding case comprises a housing having an opening for transmitting therethrough light to be detected which is directed to the photomultiplier; a lens element for guiding the light to be detected into an effective region on a photocathode; and a positioning structure for placing the photomultiplier at a desired position with respect to the lens element.

Abstract: The present invention relates to a versatile side-on type photomultiplier comprising a structure for improving the uniformity in light receiving sensitivity. Disposed on the outer peripheral surface of a sealed envelope of this photomultiplier is a restricting member which guides light to be detected into, of the light receiving surface of a photocathode, an effective region where the light receiving sensitivity is high, thereby restraining the light to be detected from reaching the outside of the effective region.

Abstract: A photomultiplier includes a photocathode (3); an electron multiplier section (60) for cascade-multiplying photoelectrons emitted from the photocathode (3); a faceplate (2) provided with the photocathode (3); a metal housing (1) accommodating the photocathode (3) and the electron multiplier section (60); and a structure disposed on the faceplate (2) for increasing the effective light entrance region of the faceplate (2). In a preferred embodiment the subject structure includes a lens element (30) attached to the faceplate for increasing the effective light entrance region of the faceplate (2). In order to improve the optical coupling efficiency, either the faceplate (2), or the lens element (30), or both the faceplate (2) and the lens element (30) may further include a protrusion.

Abstract: The present invention relates to a versatile side-on type photomultiplier comprising a structure for improving the uniformity in light receiving sensitivity. This photomultiplier comprises a positioning structure for precisely positioning, with respect to the light receiving surface of a photocathode, a lens element which guides light to be detected to a photocathode and constitutes a part of an envelope accommodating the photocathode. The precisely positioned lens element guides the light to be detected into, of the light receiving surface of the photocathode, an effective region where the light receiving sensitivity is high, thereby restraining the light to be detected from reaching the outside of the effective region.

Abstract: A light-deflecting cover for an optical pick-up apparatus has a reflecting portion disposed within a light path of a light beam projected from a light source or light returning from outside the apparatus for deflecting an optical beam for bending the light path. The light deflecting part of the cover is provided with a light absorbing portion for removing unnecessary light which does not contribute to the operating characteristics of optical equipment within which the light deflecting part is provided.

Abstract: An objective lens drive device has a supporting member to which an objective lens is attached. The supporting member is freely translated in a direction parallel to the optical axis of the objective lens and in a plane perpendicular to the optical axis. The supporting member is attached a stationary portion, and a magnetic circuit provided on the supporting member forms a closed magnetic path. A focusing coil and a plurality of tracking coils attached to the focusing coil drive the objective lens in cooperation with the magnetic circuit so that the objective lens is translated in the direction parallel to the optical axis and in the direction perpendicular to the optical axis. The focusing coil and the tracking coils are mounted on the stationary portion so as to oppose the magnetic circuit with a predetermined spacing therebetween.

Abstract: A displacement detecting system comprises an optical detector which includes a one-chip optical IC having a laser light source, light receiving elements for generating, in response to laser light reflected by a surface to be measured, a focus error signal indicative of a deviation of a distance between the surface and an objective lens from a focal length thereof, and a prism.

Abstract: An optical pickup device for a recording and/or reproducing apparatus in which a light beam from a semiconductor laser element is converged by an object lens and irradiated on recording tracks of an optical disk and the light reflected by the disk is sensed to read and/or record data signals. The device includes photosensors each having an insensitive central zone and adapted to receive the reflected light to generate tracking error signals. The semiconductor laser element is so arranged that the light beam is projected on the optical disk so that the meridional plane of the light beam orthogonal to the junction plane of semiconductor layers of the semiconductor laser element is at such an angle with respect to a tangential line drawn to one of the recording tracks of the optical disk that non-symmetricities on both sides of said tangential line as a function of the de-focusing direction of the beam spot may be compensated.

Abstract: A tracking error signal generator for producing a tracking error signal by first detecting a light beam, which is irradiated from an optical pickup to an optical disc, by an optical detector so divided as to have two optical detecting portions in a direction of a recording track on the optical disc, and then controlling the light beam to follow the recording track on the optical disc in accordance with the detection outputs from the divided optical detector.

Abstract: An optical pickup device is disclosed in which a light beam from a laser light source is converged by an object lens on a signal recording surface of an optical disk to follow recording tracks formed on the signal recording surface to read out or write data on or from the signal recording surface. A semiconductor laser unit is used as a laser light source and is so arranged that the meridional plane of the light beam emanating from the semiconductor laser unit is inclined 30.degree. to 60.degree. with respect to the tangential direction of the recording track.

Abstract: An optical head device for use in recording and/or reproduction of information comprises a light beam generating portion, a lens element for causing a light beam obtained from the light beam generating portion to impinge upon a record medium and receiving the light beam from the recording medium, and a photodetecting portion to which the light beam from the record medium received by the lens element is guided and which has three photosensitive elements separated from each other by a couple of parallel dividing portions and disposed to form a common light receiving plane on which a beam spot is formed by the light beam guided to the photodetecting portion for detecting the light beam guided to the photodetecting portion to produce respective detection output signals from which a tracking error signal is produced, wherein each of the parallel dividing portions extends along a direction selected to be at an angle within an angle rqnge of 0 to 90 degrees to a direction of movement of a diffraction pattern appeari

Abstract: An optical head device for use in a disc player comprises a movable optical assembly in which an objective lens, first and second mirrors, and a light beam generating and detecting unit are supported in common by a supporting member, and a driving mechanism for moving the movable optical assembly in both a first direction along an optical axis of the objective lens and a second direction perpendicular to the first direction, wherein, in the movable optical assembly, a light beam generated in the light beam generating and detecting unit is reflected twice by the first and second mirrors to be changed in its traveling direction, and focused by the objective lens at a position on the optical axis of the objective lens, and a light beam coming from the outside of the movable optical assembly is received by the objective lens to pass therethrough to the second mirror, reflected twice by the second and first mirrors to be changed in its traveling direction, and guided to a photodetector contained in the light beam