Abstract: An optical pickup includes a light source, an objective lens, a diffraction grating that divides an optical beam reflected from a predetermined information layer, into a plurality of optical beams, and a detector having a plurality of photo-receivers to receive a plurality of optical beams. The diffraction grating has a predetermined region for dividing from a signal light beam a region including a central portion of a spot which the signal light beam will form on the diffraction grating. A distance from a central section of the detector to that of a spot center photo-receiver on the detector, the spot center photo-receiver being provided to receive the optical beams formed by division in a predetermined region of the diffraction grating, is equal to or greater than a spot radius of the unwanted light beams entering the predetermined region of the diffraction grating, on the detector.

Abstract: An optical pickup includes a light source, an optical system for irradiating a recording medium including a plurality of recording layers with light from the light source, a diffraction optical element that divides light reflected from the recording medium into a plurality of optical fluxes and diffracts the fluxes, and an optical detector receiving the optical flux diffracted by the diffraction optical element. The optical detector includes a light receiving element detecting a focus error signal, wherein a longitudinal direction of the light receiving element is arranged to coincide with a circumferential direction of the recording medium, or arranged to be inclined to a circumferential or radial direction.

Abstract: An optical pickup includes a light source, an objective lens, a diffraction grating that divides an optical beam reflected from a predetermined information layer, into a plurality of optical beams, and a detector having a plurality of photo-receivers to receive a plurality of optical beams. The diffraction grating has a predetermined region for dividing from a signal light beam a region including a central portion of a spot which the signal light beam will form on the diffraction grating. A distance from a central section of the detector to that of a spot center photo-receiver on the detector, the spot center photo-receiver being provided to receive the optical beams formed by division in a predetermined region of the diffraction grating, is equal to or greater than a spot radius of the unwanted light beams entering the predetermined region of the diffraction grating, on the detector.

Abstract: In a light beam scanning projection apparatus which scans a light beam emitted from a laser light source, an image display apparatus is configured including a plurality of light beams, a reflection mirror for reflecting the light beams to project them onto a screen or the like, and a mirror driving unit for driving the reflection mirror so that the plurality of light beams are incident on the reflection mirror with different optical axes and projected on different projection areas, thereby displaying a single image with a plurality of images. Further, by forming a single image by causing a plurality of the light beams to have predetermined relative angles thereamong so as to make a plurality of images overlap on each other with slight shifts, a scanning projection apparatus is provided with which the luminance of the image is improved while conforming to safety standards.

Abstract: In a method and apparatus for generating a focus error signal, an optical head and an optical driving apparatus are configured such that a light beam is divided into at least two light beams, coma aberration of a predetermined direction is added to one of the divided light beams, and coma aberration of a direction different from the predetermined direction of the coma aberration is added to the other divided light beam to thereby generate the focus error signal.

Abstract: A polarizing prism is shaped in the form of a hexahedron. A polarizing beam splitter film (PBS film) is arranged approximately in a diagonal direction of the hexahedron. The polarizing prism holds a relationship of A<B when the dimension thereof in an outgoing direction (Y direction) of a light beam to a screen is A and the dimension thereof in an incident direction (X direction) of a light beam from a light source is B. For example, the polarizing prism is shaped in the form of a rectangular parallelepiped. At a plane on which the light beam is launched from a scanning mirror, one end of the PBS film is placed so as to intersect with the incident plane at an angle of approximately 45° at a position deviated inside by a difference between the dimensions A and B from the end of the incident plane.

Abstract: For use with a multi-layer optical disc, an optical pickup can eliminate a problem of causing a focus error signal and a tracking error signal to fluctuate due to interference of a signal light beam with a return light beam from another recording surface of a multi-layer optical disc during reproduction with an optical pickup that produces a tracking error signal and a focus error signal from a difference signal based on polarized reflected light.

Abstract: The present invention provides a unit and method for implementing an optical head and optical drive device whose configuration is simple, and which allows the generation of a track error signal in which no offset is caused to occur. The optical drive device includes a light source for emitting light beams, an objective lens for converging the light beams onto an optical disc, an optical-signal generation element for dividing the light beams into at least four regions by using a division line extending in the radial direction of the optical disc, and a division line extending in the track direction of the optical disc, the light beams being reflected by the optical disc, and an optical detector for receiving the light beams divided by the optical-signal generation element, wherein the up and down or right and left areas of the four regions are made different from each other.

Abstract: An optical disc device includes an optical source for emitting an optical beam, an incident intensity control circuit for controlling an intensity of the optical beam emitted from the optical source, an objective lens for focusing the optical beam on an optical disc, an optical detector for receiving the optical beam reflected from the optical disc, and a servo signal generation circuit for generating a focus error signal from the optical detector, by this configuration, the optical beam is varied once to a third optical beam intensity to be present in between a first optical beam intensity and a second optical beam intensity when varying from the first optical beam intensity up to the second optical beam intensity different from the first optical beam intensity, and the incident intensity control circuit is controlled such that the variation of focus error signal is not exceeded over a predetermined range.

Abstract: An optical head capable of recording or playing back optical discs is provided. The optical disc comprises a light source to emit a beam, an objective to focus the beam on an optical disc, a beam dividing element having a plurality of divided areas with which to divide a cross section of the beam reflected from the optical disc, and a light detector to receive the beams divided by the beam dividing element, wherein the beam dividing element has in at least one of the plurality of areas an aberration imparting function of imparting an astigmatism or defocus aberration to a beam passing through that area.

Abstract: A thin-type optical head, smaller in optic mounting spaces comprising to the conventional one, in an optic system enabling with BD including a 2-layers BD, DVD an CD, comprises a light source, for emit a light beam therefrom; an optical branch element for penetrating a predetermined amount of lights, therethrough, of an incident light beam thereon, and to reflecting remaining amount of lights thereupon; a light focusing element for focusing the light beam upon an optical information recording medium; a photo detector for receiving the light beam reflecting upon the optical information recording medium; and an optical path converter element for converting an angle of an optical path, on which the light beam propagates, wherein the optical path converter element is disposed on an optical path of the light beam between the optical branch element and the photo detector, or between the optical branch element and the light source, and has an incident surface, upon which the light beam enters, and an emission surfac

Abstract: An optical pickup includes a first source which emits a first beam with a first wavelength; a second source which emits a second beam with a wavelength shorter than the first wavelength; a first collimate lens which collimates the first beam; a second collimate lens which collimates the second beam; a first objective lens which converges the first collimated beam onto an optical disc; and a second objective lens which converges the second collimated beam onto the disc. The first and second objective lenses are arranged in the disc radial direction. The second objective lens is arranged closer to the side of the disc outer circumference than the first objective lens. The first collimate lens is arranged on the right-hand side when the second objective lens is viewed from the first objective lens. The second collimate lens is arranged on the left-hand side when the first objective lens is viewed from the second objective lens.

Abstract: An optical pickup includes a light source, an optical system for irradiating a recording medium including a plurality of recording layers with light from the light source, a diffraction optical element that divides light reflected from the recording medium into a plurality of optical fluxes and diffracts the fluxes, and an optical detector receiving the optical flux diffracted by the diffraction optical element. The optical detector includes a light receiving element detecting a focus error signal, wherein a longitudinal direction of the light receiving element is arranged to coincide with a circumferential direction of the recording medium, or arranged to be inclined to a circumferential or radial direction.

Abstract: An optical pickup equipped with a laser light source which emits light beams of at least three wavelengths for recording/reproducing a plurality of information recording media detects light quantities of the light beams of three wavelengths using one light intensity monitor element. More specifically, one light intensity monitor element is arranged between a first laser light source and a second laser light source, light beams of wavelength ?1 and wavelength ?2 emitted from the first laser light source are made to proceed substantially straightforward, the optical path of the light beam of wavelength ?3 emitted from the second laser light source is changed to a diagonal one so as to cause the light beam to be introduced diagonally to the light receiving surface of the one light intensity monitor element.

Abstract: An optical head and an apparatus using the optical head are shown. The optical head includes a light-emitting element, a first polarized light diverging element for transmitting the light beam of a first polarization direction and reflecting the light beam of a second polarization direction orthogonal to the first polarization direction, a second polarized light diverging element for transmitting or reflecting the light beam of the first polarization direction, a converging element for converging the light beam on an information recording medium, a reflection element for reflecting a first reflected light beam reflected on the information recording medium and reflected on or transmitted through the second polarized light diverging element, and a detection element for detecting a second reflected light beam reflected on the reflection element and transmitted through or reflected on the second polarized light diverging element.

Abstract: An optical pickup includes a first source which emits a first beam with a first wavelength; a second source which emits a second beam with a wavelength shorter than the first wavelength; a first collimate lens which collimates the first beam; a second collimate lens which collimates the second beam; a first objective lens which converges the first collimated beam onto an optical disc; and a second objective lens which converges the second collimated beam onto the disc. The first and second objective lenses are arranged in the disc radial direction. The second objective lens is arranged closer to the side of the disc outer circumference than the first objective lens. The first collimate lens is arranged on the right-hand side when the second objective lens is viewed from the first objective lens. The second collimate lens is arranged on the left-hand side when the first objective lens is viewed from the second objective lens.

Abstract: An optical pickup includes a first source which emits a first beam with a first wavelength; a second source which emits a second beam with a wavelength shorter than the first wavelength; a first collimate lens which collimates the first beam; a second collimate lens which collimates the second beam; a first objective lens which converges the first collimated beam onto an optical disc; and a second objective lens which converges the second collimated beam onto the disc. The first and second objective lenses are arranged in the disc radial direction. The second objective lens is arranged closer to the side of the disc outer circumference than the first objective lens. The first collimate lens is arranged on the right-hand side when the second objective lens is viewed from the first objective lens. The second collimate lens is arranged on the left-hand side when the first objective lens is viewed from the second objective lens.

Abstract: An optical pickup device including: a laser diode for emitting laser light; an objective lens which irradiates an optical beam emitted from the laser diode; an actuator which displaces the objective lens in a radius direction of the optical disc; a grating for branches an optical beam reflected by an information recording layer into plural regions; and one photodetector having plural light receiving parts for receiving the branched optical beams, wherein the photodetector has a first light receiving part which detects zero-th order grating diffracted light and plural second light receiving parts which detecting grating diffracted light having an order not less than that of ±first order grating diffracted light; a detected signal of the zero-th order grating diffracted light is defined as a reproduction signal; and a detected signal of the grating diffracted light is defined as a signal for servo controlling.

Abstract: A thin-type optical head, smaller in optic mounting spaces comprising to the conventional one, in an optic system enabling with BD including a 2-layers BD, DVD an CD, comprises a light source, for emit a light beam therefrom; an optical branch element for penetrating a predetermined amount of lights, therethrough, of an incident light beam thereon, and to reflecting remaining amount of lights thereupon; a light focusing element for focusing the light beam upon an optical information recording medium; a photo detector for receiving the light beam reflecting upon the optical information recording medium; and an optical path converter element for converting an angle of an optical path, on which the light beam propagates, wherein the optical path converter element is disposed on an optical path of the light beam between the optical branch element and the photo detector, or between the optical branch element and the light source, and has an incident surface, upon which the light beam enters, and an emission surfac

Abstract: An optical pickup includes a light source, an objective lens, a diffraction grating that divides an optical beam reflected from a predetermined information layer, into a plurality of optical beams, and a detector having a plurality of photo-receivers to receive a plurality of optical beams. The diffraction grating has a predetermined region for dividing from a signal light beam a region including a central portion of a spot which the signal light beam will form on the diffraction grating. A distance from a central section of the detector to that of a spot center photo-receiver on the detector, the spot center photo-receiver being provided to receive the optical beams formed by division in a predetermined region of the diffraction grating, is equal to or greater than a spot radius of the unwanted light beams entering the predetermined region of the diffraction grating, on the detector.