Abstract: A light detecting device includes a reception optical system that guides a reflected beam along a reception optical axis and a light receiver that outputs a detection signal by receiving the reflected beam. The light receiver forms a reception surface having a reception aspect ratio in which a long side extends along a first reference axis orthogonal to the reception optical axis. The reception surface is inclined around the first reference axis with respect to a second reference axis orthogonal to the reception optical axis and the first reference axis.

Abstract: A LiDAR device is a light detection device including a light-emitting unit, a light-receiving unit, and an optical unit. In the light-emitting unit, a plurality of VCSEL elements respectively emitting a beam are arranged along a light source array direction. The light-receiving unit receives a reflected beam from a measurement area. The optical unit includes a first optical element and a second optical element, and forms a projected beam extending along the light source array direction. The first optical element has a negative power along a transmission direction of the beam on a main scanning plane that is orthogonal to the light source array direction. The second optical element is positioned behind the first optical element, and has a positive power along the transmission direction on the main scanning plane that is orthogonal to the light source array direction.

Abstract: A LiDAR device is an optical device, including a light-emitting unit, a scanning unit, a light-receiving unit, and an optical unit. The light-emitting unit includes a plurality of laser oscillation elements respectively emitting a beam in an arrangement along a light source array direction at intervals from each other. The scanning unit projects the beam to a measurement area by scanning of the beam that is emitted from the light-emitting unit. The light-receiving unit receives a reflected beam from the measurement area. The optical unit is positioned on an optical path of the beam directed from the light-emitting unit to the scanning unit. The optical unit includes a collimator lens having a positive power in a transmission direction of the beam, and a beam shaping lens positioned behind the collimator lens and having a positive power in the transmission direction on a sub-scanning plane.

Abstract: A laser radar device includes: a light source; a mirror rotatable about a rotation shaft to reflect laser light emitted by the light source; a window; and a detector to detect laser light. The mirror has a low reflection area having a lower reflectance than the other region of the mirror, in a state where a mirror surface faces toward the light source, at position adjacent to the light source than the detector in an axial direction of the rotation shaft and adjacent to the window than a region where the laser light emitted by the light source hits for a first time in a radial direction of the rotation shaft. The window has an inclined posture in which a distance from the rotation shaft is shorter at position adjacent to the detector than at position adjacent to the light source.

Abstract: A LIDAR device includes a light source, a mirror, a rotatable shaft, and a motor. The light source configured to emit a light beam having a predetermined light beam width for scanning a scanning zone. The rotatable shaft has a center axis parallel to a reflective surface of the mirror and is connected to a back surface of the mirror. The motor is configured to rotate the shaft to cause the mirror to swing between a first position and a second position. The light source and the mirror are arranged to have a positional relationship such that a mirror center is aligned with the light beam center when the mirror is at the first position, and the mirror center shifts within a motion area when the mirror is swinging between the first position, non-inclusive, and the second position, inclusive.

Abstract: A diffractive optical element exerts a diffractive action on a display light that is emitted from a display unit. A folding mirror is provided on the opposite side of the diffractive optical element from the display unit to reflect the display light. The diffractive optical element includes a transmissive action part and a diffractive and reflective action part. The transmissive action part exerts a transmissive action to transmit therethrough the display light, which is incident from the display unit and is in a first polarization state, toward the folding mirror. The diffractive and reflective action part exerts a diffractive and reflective action to diffract and reflect the display light, which is reflected by the folding mirror and is in a second polarization state opposite to the first polarization state, toward the projection portion on an optical path.

Abstract: An optical detector includes a light emitting unit and a light receiving unit that receives a reflected light reflected by a measurement object. The light receiving unit has a detection element and a condenser lens system that collects the reflected light to the detection element. The condenser lens system has a plurality of lenses. The condenser lens system has a temperature change factor that increases the optical power at a high temperature than at a low temperature, and a chromatic aberration factor that decreases the optical power at a long wavelength than at a short wavelength. The optical power of each of the plurality of lenses is adjusted based on a correspondence between a change in temperature and a shift amount of the peak wavelength, so that the chromatic aberration factor balances with the temperature change factor within a predetermined wavelength range.

Abstract: A light guide unit forms an optical path to guide a display light emitted from a display unit toward a projection portion. The light guide unit includes a negative optical element and a positive optical element. The negative optical element is placed on the optical path and has a negative optical power. The positive optical element is placed on the optical path and is closer to the projection portion than the negative optical element. The positive optical element has a positive optical power. The positive optical element is a diffractive optical element having a diffractive structure configured to diffract the display light.

Abstract: First and second diffractive reflective elements form an optical path that guides a display light from a display unit toward a projection portion. The first diffractive reflective element is placed on the optical path to reflect the display light toward the projection portion by causing diffraction such that an incident angle and an emission angle of the display light are different from each other. The second diffractive reflective element is placed between the display unit and the first diffractive reflective element on the optical path to reflect the display light from the display unit toward the first diffractive reflective element by causing diffraction such that an incident angle and an emission angle of the display light are different from each other.

Abstract: A light diffusion member constituting a head-up display device includes multiple micro-lenses and has a curved base surface. The edge angle is larger than the base surface angle change amount. The edge angle is an angle formed by one of tangent lines of two micro-lenses and the other of the tangent lines passing through a boundary between two adjacent micro-lenses on a cross section orthogonal to the base surface. A reference line has a constant direction on the cross section, and a normal line passes at an arbitrary position on the base surface. The maximum value is ?max and the minimum value is ?min among angles between the normal line and the reference line. The base surface angle change amount is the absolute value of the difference between ?max and ?min.

Abstract: A virtual image display device displays a virtual image by projecting a display light of an image toward a projection unit, and includes: a display unit configured to emit the display light; and a diffraction reflection element configured to reflect the display light emitted from the display unit by diffraction. The diffraction reflection element has a plate shape along a horizontal plane. The diffraction reflection element is configured to emit the display light toward the projection unit arranged above the diffraction reflection element when the display light is incident, and is set such that an angle of incidence on the diffraction reflection element is larger than an angle of emission from the diffraction reflection element.

Abstract: An optical detector includes a light emitter having a light emitting window extended in an extension direction to emit a projection beam from the light emitting window toward a measurement area and to detect a return beam from the measurement area. The optical detector includes a scanning mirror that scans by reflecting the projection beam. The scanning mirror swings within a finite angular range around a rotation axis that is along a direction corresponding to the extension direction.

Abstract: A LIDAR device includes a light source, a mirror, a rotatable shaft, and a motor. The light source configured to emit a light beam having a predetermined light beam width for scanning a scanning zone. The rotatable shaft has a center axis parallel to a reflective surface of the mirror and is connected to a back surface of the mirror. The motor is configured to rotate the shaft to cause the mirror to swing between a first position and a second position. The light source and the mirror are arranged to have a positional relationship such that a mirror center is aligned with the light beam center when the mirror is at the first position, and the mirror center shifts within a motion area when the mirror is swinging between the first position, non-inclusive, and the second position, inclusive.

Abstract: An optical detector is configured to project a projection beam toward a measurement area and detect a return beam from the measurement area. The optical detector includes: a projecting optical system that forms a projection optical axis to project the projection beam; a receiving optical system that forms a receiving optical axis to receive the return beam, and a housing having a housing chamber to house the projecting optical system and the receiving optical system, and an optical window for the projection beam and the return beam to travel between the housing chamber and the measurement area. The projection optical axis and the receiving optical axis are offset from each other to define an overlap region inside the housing chamber where footprints of the projection beam and the return beam overlap with each other.

Abstract: A laser projection portion projects multiple laser light fluxes having different wavelengths and superimposed one on another. A scan portion scans the laser light fluxes from the laser projection portion. The image is drawn on a screen member upon incidence of the laser light fluxes scanned by the scan portion. A refraction element portion having positive refractive power is located on a light path between the scan portion and the screen member and adjusts an incident angle of the laser light fluxes to the screen member by refraction. The refraction element portion includes a positive lens part and a negative lens part. The positive lens part has positive refractive power. The negative lens part is made of a medium with a higher dispersing quality than a medium forming the positive lens part and has negative refractive power.

Abstract: First and second diffractive reflective elements form an optical path that guides a display light from a display unit toward a projection portion. The first diffractive reflective element is placed on the optical path to reflect the display light toward the projection portion by causing diffraction such that an incident angle and an emission angle of the display light are different from each other. The second diffractive reflective element is placed between the display unit and the first diffractive reflective element on the optical path to reflect the display light from the display unit toward the first diffractive reflective element by causing diffraction such that an incident angle and an emission angle of the display light are different from each other.

Abstract: A diffractive optical element exerts a diffractive action on a display light that is emitted from a display unit. A folding mirror is provided on the opposite side of the diffractive optical element from the display unit to reflect the display light. The diffractive optical element includes a transmissive action part and a diffractive and reflective action part. The transmissive action part exerts a transmissive action to transmit therethrough the display light, which is incident from the display unit and is in a first polarization state, toward the folding mirror. The diffractive and reflective action part exerts a diffractive and reflective action to diffract and reflect the display light, which is reflected by the folding mirror and is in a second polarization state opposite to the first polarization state, toward the projection portion on an optical path.

Abstract: A light guide unit forms an optical path to guide a display light emitted from a display unit toward a projection portion. The light guide unit includes a negative optical element and a positive optical element. The negative optical element is placed on the optical path and has a negative optical power. The positive optical element is placed on the optical path and is closer to the projection portion than the negative optical element. The positive optical element has a positive optical power. The positive optical element is a diffractive optical element having a diffractive structure configured to diffract the display light.

Abstract: A light diffusion member constituting a head-up display device includes multiple micro-lenses and has a curved base surface. The edge angle is larger than the base surface angle change amount. The edge angle is an angle formed by one of tangent lines of two micro-lenses and the other of the tangent lines passing through a boundary between two adjacent micro-lenses on a cross section orthogonal to the base surface. A reference line has a constant direction on the cross section, and a normal line passes at an arbitrary position on the base surface. The maximum value is ?max and the minimum value is ?min among angles between the normal line and the reference line. The base surface angle change amount is the absolute value of the difference between ?max and ?min.

Abstract: In a head-up display, a cover member includes a first transmissive member and a second transmissive member that transmit a light beam including an image generated by an image generation unit. The first transmissive member is formed to face upward from a front end to a rear end. Likewise, the second transmissive member is formed to face upward from a front end to a rear end. The rear end of the first transmissive member is offset to an upper side from the front end of the second transmissive member.