摘要:
A high-resolution light-beam scanning apparatus utilizing only mass-producible holograms instead of utilizing auxiliary optical systems, and capable of compensating for disadvantages. The light-beam scanning apparatus including diffraction gratings for minimizing either: a sum total of values obtained by weighting a square of an optical path length difference between an optical path of a light flux measured along a principal axis of a light beam incident on and diffracted by a first diffraction grating of a rotatable hologram, and incident on and diffracted by a second diffraction grating of a fixed plate to conduct a scanning and converging on a scanning point on an image formation surface, and an optical path of a light flux measured along a marginal ray distanced from the principal axis or an absolute value of the optical path difference thereof; or a sum total of values obtained by weighting a square of a sum obtained by adding an amount of displacement of a light-beam convergent on a scanning point on the image formation surface, to an amount of displacement of the same light. The displacement measured with respect to the principal axis of a phase recorded on the diffraction grating when the light flux is incident on the fixed plate or by weighting an absolute value of the sum. The weighting is conducted at every scanning position of an image formation surface.
摘要:
A high-resolution light-beam scanning apparatus including a rotatable hologram and a fixed plate which are diffraction gratings for minimizing either a sum total of values obtained by weighting (1): a square of an optical path length difference between a) an optical path of a light flux measured along a principal axis of a light beam incident on and diffracted by a first diffraction grating of the rotatable hologram, and incident on and diffracted by a second diffraction grating of the fixed plate so as to conduct a scanning and converging on an image formation surface scanning point, and b) an optical path of a light flux measured along a marginal ray distanced from the principal axis, or an absolute value of the optical path difference thereof; or (2) a square of a sum obtained by adding an amount of displacement of a light beam convergent on the scanning point, which displacement is measured along the marginal ray distanced from the principal axis of an incident reconstructing light flux with respect to the principal axis of a phase of the first diffraction grating, to an amount of displacement of the same light, which displacement is measured with respect to the principal axis of a phase recorded on the second diffraction grating, when the light flux is incident on the fixed plate, or by weighting an absolute value of the sum, each weighting being conducted at every scanning position covering an entire range of the image formation surface.
摘要:
A high-resolution light-beam scanning apparatus utilizing only mass-producible holograms instead of utilizing auxiliary optical systems, and capable of compensating for disadvantages. The light-beam scanning apparatus including diffraction gratings for minimizing either: a sum total of values obtained by weighting a square of an optical path length difference between an optical path of a light flux measured along a principle axis of a light beam incident on and diffracted by a first diffraction grating of a rotatable hologram, and incident on and diffracted by a second diffraction grating of a fixed plate to conduct a scanning and converging on a scanning point on an image formation surface, and an optical path of a light flux measured along a marginal ray distanced from the principal axis or an absolute value of the optical path difference thereof; or a sum total of values obtained by weighting a square of a sum obtained by adding an amount of displacement of a light-beam convergent on a scanning point on the image formation surface, to an amount of displacement of the same light. The displacement measured with respect to the principal axis of a phase recorded on the diffraction grating when the light flux is incident on the fixed plate or by weighting an absolute value of the sum. The weighting is conducted at every scanning position of an image formation surface.
摘要:
An optical beam scanning apparatus includes one rotatable hologram which is rotatable about an axis, and at least two laser beam sources which emit laser beams. The rotatable hologram is provided with at least two hologram areas whose number corresponds to the number of the laser beam sources, so that the laser beams emitted from the respective laser beam sources are made incident upon the respective hologram areas. Each of the hologram areas is provided with a plurality of hologram facets which are concentrically arranged with respect to the axis of rotation of the rotatable hologram to emit laser beams of the same F number. The hologram areas having different numbers of hologram facets having different F numbers.
摘要:
A high-resolution light-beam scanning apparatus utilizing only mass-producible holograms instead of utilizing auxiliary optical systems, and capable of compensating for disadvantages. The light-beam scanning apparatus including diffraction gratings for minimizing either: a sum total of values obtained by weighting a square of an optical path length difference between an optical path of a light flux measured along a principal axis of a light beam incident on and diffracted by a first diffraction grating of a rotatable hologram, and incident on and diffracted by a second diffraction grating of a fixed plate to conduct a scanning and converging on a scanning point on an image formation surface, and an optical path of a light flux measured along a marginal ray distanced from the principal axis or an absolute value of the optical path difference thereof; or a sum total of values obtained by weighting a square of a sum obtained by adding an amount of displacement of a light-beam convergent on a scanning point on the image formation surface, to an amount of displacement of the same light. The displacement measured with respect to the principal axis of a phase recorded on the diffraction grating when the light flux is incident on the fixed plate or by weighting an absolute value of the sum. The weighting is conducted at every scanning position of an image formation surface.
摘要:
An optical scanning system includes a laser source, a deflector deflecting a laser beam emitted from the laser source, and at least two hologram elements located between the deflector and an image forming member.
摘要:
A headup display apparatus consists of a projection optical system unit installed in the dashboard of a car and a reflection member on the windshield. The projection optical system unit contains an indicator and an off-axis reflective hologram which reflects display light of the indicator toward the windshield, which in turn reflects it toward the viewing point of a driver. As a result, the display is seen superimposed on the exterior view. When external light as from the sun enters the projection optical system unit traveling in a direction reverse to the path of the display light, the off-axis reflective hologram reflects the incident external light toward a direction different from that of the outgoing display light to minimize an abnormal illumination of the indicator surface which would otherwise render the display unrecognizable. Behind the hologram is installed a heat dissipating member that receives infrared rays that have transmitted the hologram in order to dissipate heat.
摘要:
An achromatic hologram optical system for converting a wave front A into a wave front B. Two holograms (H.sub.1 and H.sub.2) are provided. The length of an optical path from an equiphase front of the wave front A to an equiphase front of the wave front B is constant, and each of the two holograms has a curved surface shape.
摘要:
A light-beam scanning apparatus includes at least two holograms with an optical path length difference .DELTA..PHI. along a scanning beam light flux. The path length is measured from a light source to a scanning surface in the first hologram, and is represented by .DELTA..PHI.
摘要:
A high-resolution light-beam scanning apparatus utilizing only mass-producible holograms instead of utilizing auxiliary optical systems such as optical lenses or a mirror having curvature, and capable of compensating for disadvantages including scanning beam thickening and variation, failure of a rotatable hologram to rotate at a constant velocity, displacement of a scanning beam position in the scanning direction and the cross scanning direction due to a mode hop of a wavelength of a semiconductor laser, and deviation of a base of rotatable hologram from a parallel state. These disadvantages are detrimental to efforts for increasing the resolution of a hologram scanner and lowering the cost thereof. The light beam scanning apparatus includes at least two holograms with an optical path length difference .DELTA..PHI. along a scanning beam light flux. The path length is measured from a light source to a scanning surface in the first hologram, and is represented by .DELTA..PHI.