Abstract: A light source emits light with a first wavelength and light with a second wavelength longer than the first wavelength toward an optical disk from adjacent positions. An optical receiver detects light reflected from the optical disk. An astigmatism-generating element generates light used for focus control in a condition where a focusing position on one of two perpendicular cross sections including an optical axis of the light reflected from the optical disk is located ahead of the optical receiver and a focusing position on the other cross section is located behind the optical receiver are included. The astigmatism-generating element is a Fresnel mirror configured to include a plurality of reflecting mirrors. A level difference between the reflecting mirrors adjacent to each other is distributed in a range from a depth of substantially (natural number/2) times the first wavelength to (natural number/2) times the second wavelength.

Abstract: An optical pickup device includes: a laser source for emitting, to an optical disk, a laser beam having a wavelength ?1 and a laser beam having a wavelength ?2, which is longer than the wavelength ?1; a light receiver, for receiving laser beams that are reflected by the optical disk; a beam splitter, for directing, to the light receiver, the laser beams reflected by the optical disk; and an astigmatism generation element, located between the beam splitter and the light receiver, for generating the laser beams to be used for focusing control, by designating as the front of the light receiver a focal point on one of the intersecting cross sections that include the light axes of the laser beams, and by designating as the rear of the light receiver, a focal point on the other cross section, wherein the astigmatism generation element is an optical element, which is like a Fresnel lens, whose step depth is substantially a natural number times either the wavelength ?1 or the wavelength ?2.

Abstract: A light source, an objective lens, and an astigmatism generation element producing for light for focus control, and an optical receiver are provided. The astigmatism generation element is interposed between the objective lens and the optical receiver and produces focal points in front of and behind the optical receiver within two mutually orthogonal cross-sectional planes including an optical axis of the reflected light. The astigmatism generation element is a Fresnel mirror that has a plurality of orbicular zones and steps connecting adjacent orbicular zones to each other and that takes the orbicular zones as reflecting mirrors. A depth “d” of the steps is set substantially one-half of a wavelength ?, and a depth d1 of the innermost orbicular zone of the orbicular zones is made larger than the depth d of the steps. The influence of the steps of the Fresnel mirror is minimized, so that a superior servo characteristic can be exhibited.

Abstract: An optical pickup and an optical disk apparatus of the invention includes a light source 1 mounted with a light-emitting element constituted of a monoblock on a surface of a plate 6 and emitting plural light beams, a light-receiving element 2, optical members 4, 5 and a coupling base 3 for coupling the light source 1, the light-receiving element 2 and the optical members 4, 5, wherein a light from the light source 1 is directed through the optical members 4, 5 toward an optical disk, and a returning light from the optical disk is guided through the optical members 4, 5 to the light-receiving element 2, characterized in that the plate 6 provided in the light source 1 and the coupling base 3 are adjoined by a solder.

Abstract: An optical pickup device or an optical disk device includes: a light source 11 that emits a laser beam toward an optical disk 25; an optical receiver 18 that detects light reflected from the optical disk 25; and an astigmatism-generating element 31 that generates light used for focus control in a condition where a focusing position on one of two perpendicular cross sections including an optical axis of the light reflected from the optical disk 25 is located ahead of the optical receiver 18 and a focusing position on the other cross section is located behind the optical receiver 18. The astigmatism-generating element is a Fresnel mirror 31a configured to include a plurality of reflecting mirrors, and an imaginary surface 31d that connects the tips of the reflecting mirrors is curved in a concave shape toward a light incidence side.

Abstract: A light source emits light with a first wavelength and light with a second wavelength longer than the first wavelength toward an optical disk from adjacent positions. An optical receiver detects light reflected from the optical disk. An astigmatism-generating element generates light used for focus control in a condition where a focusing position on one of two perpendicular cross sections including an optical axis of the light reflected from the optical disk is located ahead of the optical receiver and a focusing position on the other cross section is located behind the optical receiver are included. The astigmatism-generating element is a Fresnel mirror configured to include a plurality of reflecting mirrors.

Abstract: It is an object to provide a laser module in which the position and the posture of a laser beam source can be adjusted even in a small space so that an optical intensity necessary for recording and reproducing information can be ensured and the laser module is seldom affected by an ambient temperature. It is another object of the present invention to provide an optical pickup device, an optical disk device, a focus error detection method and a tracking error detection method. The laser beam source adjustment member 55 and the laser beam source shift member 56 are attached to the laser beam source 52 so that the lead 51 can penetrate them. Further, FPC 57 is fixed to the lead 51 being soldered. The laser beam source 52 and the laser beam source adjustment member 55 are fixed between the holding plate 54 and the laser beam source shift member 56 being pushed by the pushing spring 53.

Abstract: An optical pickup device includes: a laser source for emitting, to an optical disk, a laser beam having a wavelength ?1 and a laser beam having a wavelength ?2, which is longer than the wavelength ?1; a light receiver, for receiving laser beams that are reflected by the optical disk; a beam splitter, for directing, to the light receiver, the laser beams reflected by the optical disk; and an astigmatism generation element, located between the beam splitter and the light receiver, for generating the laser beams to be used for focusing control, by designating as the front of the light receiver a focal point on one of the intersecting cross sections that include the light axes of the laser beams, and by designating as the rear of the light receiver, a focal point on the other cross section, wherein the astigmatism generation element is an optical element, which is like a Fresnel lens, whose step depth is substantially a natural number times either the wavelength ?1 or the wavelength ?2.

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 apparatus, comprises: a light source in which a plurality of light emitting points having different wavelengths are provided; a light receiving unit, receiving light reflected from an optical disk to produce an electric signal; and an optical system, collecting light emitted from the respective light emitting points to the optical disk and conducting the light reflected from the optical disk to the light receiving unit; wherein the optical system includes a filter which converts the light emitted from the respective light emitting points into a predetermined optical intensity distribution.

Abstract: An optical pickup and an optical disk apparatus of the invention includes a light source 1 mounted with a light-emitting element constituted of a monoblock on a surface of a plate 6 and emitting plural light beams, a light-receiving element 2, optical members 4, 5 and a coupling base 3 for coupling the light source 1, the light-receiving element 2 and the optical members 4, 5, wherein a light from the light source 1 is directed through the optical members 4, 5 toward an optical disk, and a returning light from the optical disk is guided through the optical members 4, 5 to the light-receiving element 2, characterized in that the plate 6 provided in the light source 1 and the coupling base 3 are adjoined by a solder.

Abstract: It is an object to provide a laser module in which the position and the posture of a laser beam source can be adjusted even in a small space so that an optical intensity necessary for recording and reproducing information can be ensured and the laser module is seldom affected by an ambient temperature. It is another object of the present invention to provide an optical pickup device, an optical disk device, a focus error detection method and a tracking error detection method. The laser beam source adjustment member 55 and the laser beam source shift member 56 are attached to the laser beam source 52 so that the lead 51 can penetrate them. Further, FPC 57 is fixed to the lead 51 being soldered. The laser beam source 52 and the laser beam source adjustment member 55 are fixed between the holding plate 54 and the laser beam source shift member 56 being pushed by the pushing spring 53.

Abstract: Provided are an integrated optical component which can prevent a detection optical system being affected by variation in working temperature, and a pick-up device using the integrated optical component. The integrated optical component for guiding a light beam emitted from a light emitting element to an optical disc, and for separating a required light beam from reflected light from the optical disc, wherein the integrated optical component includes therein a plurality of optical surfaces, and a diffraction grating for extracting light beams required from tracking control and focus control, from the reflected light is formed in any one of the optical surfaces.

Abstract: A small-sized, inexpensive optical pickup apparatus can be assembled with high accuracy. The optical pickup apparatus has a various-purpose semiconductor laser, an integrated optical assembly for guiding outgoing light to an optical disk and for separating reflected light, a light receiver for receiving light and converting the received light into an electrical signal, and a coupling member for retaining a positional relationship among the various-purpose semiconductor laser, the integrated optical assembly, and the light receiver. By using a various-purpose semiconductor laser, the optical pickup apparatus can be made in a small size at low cost, and can be accurately assembled. The apparatus is also capable of accurately and efficiently detecting the optical power of the various-purpose semiconductor laser.

Abstract: Provided are a thin optical pick-up apparatus which can record and reproduce data to and from both high recording density disc and low recording density disc, and a thin optical disc unit using this optical pick-up apparatus. The optical pick-up apparatus comprises a short wave LDA 11, a long wave LDAB 12, a beam splitter 41, a riser prism 23 for turning an optical axis into an optical axis perpendicular to the optical disc, a composite filter 33 being integrally incorporated with the objective lens 32 while a surface of the composite filter 33 is opposed to an oblique surface of the riser prism 23 in parallel with each other.

Abstract: In an optical pickup device for recording information onto and/or reading out information from an optical recording medium, comprising a light beam source for generating a light beam to be projected toward the optical recording medium, and a light beam detector for receiving the light beam reflected by the optical recording medium so that the information is read out from the light beam after reflected by the optical recording medium, a container houses therein the light beam source and includes an aperture through which the light beam proceeds toward the optical recording medium, and a light beam guide member is mounted on an outer surface of the container and covers the aperture to guide the light beam after reflected by the optical recording medium toward the light beam detector.

Abstract: Provided are an integrated optical component which can prevent a detection optical system being affected by variation in working temperature, and a pick-up device using the integrated optical component. The integrated optical component for guiding a light beam emitted from a light emitting element to an optical disc, and for separating a required light beam from reflected light from the optical disc, wherein the integrated optical component includes therein a plurality of optical surfaces, and a diffraction grating for extracting light beams required from tracking control and focus control, from the reflected light is formed in any one of the optical surfaces.

Abstract: A small-sized, inexpensive optical pickup apparatus can be assembled with high accuracy. The optical pickup apparatus has a various-purpose semiconductor laser, an integrated optical assembly for guiding outgoing light to an optical disk and for separating reflected light, a light receiver for receiving light and converting the received light into an electrical signal, and a coupling member for retaining a positional relationship among the various-purpose semiconductor laser, the integrated optical assembly, and the light receiver. By using a various-purpose semiconductor laser, the optical pickup apparatus can be made in a small size at low cost, and can be accurately assembled. The apparatus is also capable of accurately and efficiently detecting the optical power of the various-purpose semiconductor laser.

Abstract: An optical pickup device has a single light beam path in which at least one or either of a plurality of kinds of light beams (different from each other in, for example, wavelength) for respective recording densities and/or recording-medium-thicknesses proceeds toward a surface of an optical recording medium and proceeds to a light beam detector after being reflected by the surface.

Abstract: An optical pickup device has a single light beam path for common use in treating or passing either of a plurality of kinds of light beams for respective recording densities and/or recording-medium-thicknesses different from each other, in other words, at least one or either of the plurality of kinds of light beams is introduced into the common single light beam path which may includes a single quarter-wave plate and/or single collimator and/or single objective.