Abstract: The recording and reproducing apparatus has rotary drive unit (a motor) that rotationally drives a multilayer recordable recording medium 1; a reference-light-side recording and reproducing lens 6 and a recording-light-side recording and reproducing lens 7 that are disposed oppositely to the recording medium 1 which is rotationally driven by the rotary drive unit, an address detection lens 5 that is disposed opposite the recording medium 1 and that is provided separately from the recording and reproducing lenses 6 and 7; a light source 9 for recording and reproducing purpose that supplies recording reproduction light to the recording and reproducing lenses 6 and 7; and the address light source 9 that supplies address light to the address detection lens 5. The apparatus is configured in such a way that light whose center axis portion is optically hollow is supplied from the reference-light-side recording and reproducing lens 6 to the recording medium 1 during reproducing operation.

Abstract: An optical pickup device includes a first laser element that emits first laser light, a second laser element that emits second laser light of which the wavelength is longer than that of the first laser light, an optical path composition element that composes the first laser light and the second laser light to one optical path, a wavelength selective element that acts on the composed first or second laser light; and an objective lens that condenses the first laser light and the second laser light on an optical disk. The magnitude of the power of the wavelength selective element as a lens with respect to the second laser light is larger than the magnitude of the power of the wavelength selective element as a lens with respect to the first laser light. Accordingly, it may be possible to reduce the optical pickup device and the optical disk apparatus in size.

Abstract: Then, in order to achieve the above-described object, in the optical disk of the present invention, while micro-hologram layers 7 and 8 made of plural layers are provided in an inner portion of a plate body 2 along a thickness direction of the plate body 2, dimensions of micro-holograms 4 along the thickness direction of the plate body 2, which configure the micro-hologram layer 7 formed on the side of one surface of the plate body 2 within the micro-hologram layers 7 and 8 constructed of the plural layers, are made smaller than dimensions of micro-holograms 3 along the thickness direction of the plate body 2, which configure a micro-hologram layer 8 formed on the side of an inner layer of the plate body 2.

Abstract: A recording apparatus includes a first light source irradiating first laser light, a second light source irradiating second laser light, an optical spatial modulating unit applying information to the first laser light, and an objective lens collecting the first laser light and the second laser light at different positions on the same optical axis. A hologram recording operation uses a first optical path and a second optical path. The information light is conducted to the objective lens along the first optical path. The reference light is conducted to the objective lens along the second optical path. At the same time, an address/servo control operation is carried out by employing a third optical path along which the second laser light is conducted to the objective lens. The DVD recording operation uses the second optical path. The CD recording operation uses the third optical path.

Abstract: An electronic device that performs at least reading or regeneration of data in or from a hologram disc is characterized by including an objective lens 11 disposed opposite a hologram disc (MH) 1; a laser light source 5 that emits a beam toward the objective lens 11; and a light receiving element 17 that receives a beam reflected from the hologram disc (MH) 1 by way of the objective lens 11, wherein a corner cube array 8 that reflects a portion of a beam traveling from the laser light source 5 toward the objective lens 11 is interposed between the laser light source 5 and the objective lens 11.

Abstract: An optical pickup device includes a first laser element that emits first laser light, a second laser element that emits second laser light of which the wavelength is longer than that of the first laser light, an optical path composition element that composes the first laser light and the second laser light to one optical path, a wavelength selective element that acts on the composed first or second laser light; and an objective lens that condenses the first laser light and the second laser light on an optical disk. The magnitude of the power of the wavelength selective element as a lens with respect to the second laser light is larger than the magnitude of the power of the wavelength selective element as a lens with respect to the first laser light. Accordingly, it may be possible to reduce the optical pickup device and the optical disk apparatus in size.

Abstract: Then, in order to achieve the above-described object, in the optical disk of the present invention, while micro-hologram layers 7 and 8 made of plural layers are provided in an inner portion of a plate body 2 along a thickness direction of the plate body 2, dimensions of micro-holograms 4 along the thickness direction of the plate body 2, which configure the micro-hologram layer 7 formed on the side of one surface of the plate body 2 within the micro-hologram layers 7 and 8 constructed of the plural layers, are made smaller than dimensions of micro-holograms 3 along the thickness direction of the plate body 2, which configure a micro-hologram layer 8 formed on the side of an inner layer of the plate body 2.

Abstract: The recording and reproducing apparatus has rotary drive unit (a motor) that rotationally drives a multilayer recordable recording medium 1; a reference-light-side recording and reproducing lens 6 and a recording-light-side recording and reproducing lens 7 that are disposed oppositely to the recording medium 1 which is rotationally driven by the rotary drive unit, an address detection lens 5 that is disposed opposite the recording medium 1 and that is provided separately from the recording and reproducing lenses 6 and 7; a light source 9 for recording and reproducing purpose that supplies recording reproduction light to the recording and reproducing lenses 6 and 7; and the address light source 9 that supplies address light to the address detection lens 5. The apparatus is configured in such a way that light whose center axis portion is optically hollow is supplied from the reference-light-side recording and reproducing lens 6 to the recording medium 1 during reproducing operation.

Abstract: A recording apparatus includes a first light source irradiating first laser light, a second light source irradiating second laser light, an optical spatial modulating unit applying information to the first laser light, and an objective lens collecting the first laser light and the second laser light at different positions on the same optical axis. A hologram recording operation uses a first optical path and a second optical path. The information light is conducted to the objective lens along the first optical path. The reference light is conducted to the objective lens along the second optical path. At the same time, an address/servo control operation is carried out by employing a third optical path along which the second laser light is conducted to the objective lens. The DVD recording operation uses the second optical path. The CD recording operation uses the third optical path.

Abstract: In a bidirectional optical module, a technique for attaining a miniaturization and a lower cost of a bidirectional optical module in which one optical fiber propagation path can be bused in two ways is disclosed. According to this technique, a molded product 12 is made of a transparent material, and a beam splitter layer 121 is inclined and embedded. A sub carrier 15 has a stage portion constituting an upper stage and a lower stage and is mounted on a flat top plane of a carrier 19. A semiconductor laser 14 is mounted on the upper stage of the sub-carrier, and a light receiving device 13 is mounted at a lower position of the molded product on the lower stage, and a side of the molded product is mounted on the side, and the respective planes are consequently bonded.

Abstract: An optical pickup for use in optically recording or picking up information on and from a recording medium using a light-emitting device. The optical pickup comprises first and second light reflecting surfaces disposed in opposed relation to each other, the first reflecting surface reflects a light beam from the light-emitting device and the second reflecting surface reflects the light beam reflected from the first reflecting surface. Around the first reflecting surface there is provide a grating lens which condenses the light beam reflected from the second reflecting surface to be focused on the recording medium. The light beam from the recording medium is reflected by the second reflecting surface to be directed to the first reflecting surface. The first reflecting surface diffracts the reflected light beam from the second reflecting surface toward a light receiving device to read the information concurrently detecting focusing and tracking error signals.

Abstract: Not more than one compound holographic optical element is provided on an optical path starting from a semiconductor laser chip and arriving at a photo detector via an optical disk. A hologram pattern of this compound holographic optical element is the superposition of a first hologram pattern, converging a laser beam emitted from the semiconductor laser chip onto the optical disk, and a second hologram pattern, diffracting the laser beam reflected at the optical disk toward the photo detector and changing it into a focusing beam. This single holographic optical element not only realizes the convergence of the laser beam onto the optical disk and/or the photo detector and the differentiation of going and returning optical paths but reduces the size and production cost of the optical pick-up apparatus.

Abstract: An optical pickup for use in optically recording or picking up information on and from a recording medium using a light-emitting device. The optical pickup comprises first and second light reflecting surfaces disposed in opposed relation to each other, the first reflecting surface reflects a light beam from the light-emitting device and the second reflecting surface reflects the light beam reflected from the first reflecting surface. Around the first reflecting surface there is provide a grating lens which condenses the light beam reflected from the second reflecting surface to be focused on the recording medium. The light beam from the recording medium is reflected by the second reflecting surface to be directed to the first reflecting surface. The first reflecting surface diffracts the reflected light beam from the second reflecting surface toward a light receiving device to read the information concurrently detecting focusing and tracking error signals.

Abstract: An optical pickup for use in optically recording or picking up information on and from a recording medium using a light-emitting device. The optical pickup comprises first and second light reflecting surfaces disposed in opposed relation to each other, the first reflecting surface reflects a light beam from the light-emitting device and the second reflecting surface reflects the light beam reflected from the first reflecting surface. Around the first reflecting surface there is provide a grating lens which condenses the light beam reflected from the second reflecting surface to be focused on the recording medium. The light beam from the recording medium is reflected by the second reflecting surface to be directed to the first reflecting surface. The first reflecting surface diffracts the reflected light beam from the second reflecting surface toward a light receiving device to read the information concurrently detecting focusing and tracking error signals.

Abstract: Not more than one compound holographic optical element is provided on an optical path starting from a semiconductor laser chip and arriving at a photo detector via an optical disk. A hologram pattern of this compound holographic optical element is the superposition of a first hologram pattern, converging a laser beam emitted from the semiconductor laser chip onto the optical disk, and a second hologram pattern, diffracting the laser beam reflected at the optical disk toward the photo detector and changing it into a focusing beam. This single holographic optical element not only realizes the convergence of the laser beam onto the optical disk and/or the photo detector and the differentiation of going and returning optical paths but reduces the size and production cost of the optical pick-up apparatus.

Abstract: An optical pickup to be used in an optical disc apparatus for optically recording and reproducing information on and from an optical disc. The optical pickup is arranged such that a laser light from a semiconductor laser is reflected plural times within an optical system and then focused on the optical disc and the light from the optical disc is diffracted by a hologram and then received by a light-receiving device for reproducing the information recorded on the optical disc. This arrangement can achieve the size-reduction of the optical pickup concurrently with obtaining a necessary optical path length.