Abstract: A position of a first module (12a) with respect to an optical fiber (11) is determined in accordance with a receiving efficiency at the first module (12a) with respect to light emitted from the optical fiber (11). Power of light coupled into the optical fiber (11) from the first module (12a) is set in accordance with a value of a far-end reflectivity on a side of the first module (12a) in the position so as to satisfy a predetermined formula. By giving priority to determining a condition that significantly influences an improvement of an eye opening ratio, it is possible to manufacture an optical communication system at a low cost and with more freedom in manufacturing. Thus provided is a method of manufacturing an optical communication system, the method allowing for manufacturing an optical communication system at a low cost and with more freedom in manufacturing.

Abstract: A beam shaping element includes a set of diffraction gratings on each surface thereof, in such a manner that intervals between the gratings farer from a vicinity of an optical axis and nearer to a periphery are narrower, wherein each interval between the respective gratings monotonously increases or monotonously decreases along a direction in which each grating-shaped pattern extends. According to the arrangement above, it is possible to correct displacement of a light emitting point of a light source by simply performing a positional adjustment within a plane that is orthogonal to the optical axis. Thus, it is possible to provide the beam shaping element that enables to correct the displacement of the light emitting point of the light source simply by performing positional adjustment in the plane vertical to the optical axis, thereby making it unnecessary to perform positional adjustment along the optical axis direction, and to provide a light source unit and an optical pickup using the beam shaping element.

Abstract: A sealing structure includes a lead frame having a light transmitting section, an optical element having an optical surface which is directed to the light transmitting section and is mounted on the lead frame in such a state that the optical element blocks the light transmitting section at its one end portion in an axis direction, and a sealing body that is formed in a region excluding an optical path and seals the optical element. By forming the sealing body in the region excluding the optical path, the light usage efficiency can be prevented from decreasing even when a material that can increase the environmental resistance is added to the sealing body. Further, since the optical element is mounted on the lead frame with its face down, the sealing structure can be easily formed even when the optical element is small-sized.

Abstract: An optical communication system has a plastic optical fiber (POF) and an optical communication module. The POF has a spherical end surface, and light emitted from the spherical end surface has an NA of 0.35 or lower. The POF is installed in the module such that a light receiving surface of a light receiving element (PD) is at a distance, d, from an apex of the spherical end surface. The distance, d, is within a range of 0<d?r*D/(n?n1) when a PD diameter is not larger than D, and within a range of D?d?r*D/(n?n1) when the PD diameter is larger than D, where D is a diameter of the POF, r*D is a radius of curvature of the spherical end surface, n is a refractive index of a core of the POF, and n1 is a refractive index of a substance between the spherical end surface and the PD.

Abstract: An optical communication system has a plastic optical fiber (POF) and an optical communication module. The POF has a spherical end surface, and light emitted from the spherical end surface has an NA of 0.35 or lower. The POF is installed in the module such that a light receiving surface of a light receiving element (PD) is at a distance, d, from an apex of the spherical end surface. The distance, d, is within a range of 0<d?r*D/(n?n1) when a PD diameter is not larger than D, and within a range of D?d?r*D/(n?n1) when the PD diameter is larger than D, where D is a diameter of the POF, r*D is a radius of curvature of the spherical end surface, n is a refractive index of a core of the POF, and n1 is a refractive index of a substance between the spherical end surface and the PD.

Abstract: An optical pickup device which includes (A) a light source, and (B) an objective lens and an aberration correcting optical system which are located in a light path from the light source to an optical recording medium is so arranged that the aberration correcting optical system imparts a phase distribution to luminous flux which transmits the aberration correcting optical system, so as to correct a predetermined aberration; and an amount of phase of the aberration correcting optical system when correcting the aberration is set in such a manner that the aberration correcting optical system imparts a larger amount of phase at a position farther from a point where the aberration correcting optical system crosses an optical axis of light emitted from the light source. With this, it is possible to increase a tolerance for the center misalignment of the objective lens so as to reduce aberration caused by the center misalignment.

Abstract: A position of a first module (12a) with respect to an optical fiber (11) is determined in accordance with a receiving efficiency at the first module (12a) with respect to light emitted from the optical fiber (11). Power of light coupled into the optical fiber (11) from the first module (12a) is set in accordance with a value of a far-end reflectivity on a side of the first module (12a) in the position so as to satisfy a predetermined formula. By giving priority to determining a condition that significantly influences an improvement of an eye opening ratio, it is possible to manufacture an optical communication system at a low cost and with more freedom in manufacturing. Thus provided is a method of manufacturing an optical communication system, the method allowing for manufacturing an optical communication system at a low cost and with more freedom in manufacturing.

Abstract: An optical pickup device which includes (A) a light source, and (B) an objective lens and an aberration correcting optical system which are located in a light path from the light source to an optical recording medium is so arranged that the aberration correcting optical system imparts a phase distribution to luminous flux which transmits the aberration correcting optical system, so as to correct a predetermined aberration; and an amount of phase of the aberration correcting optical system when correcting the aberration is set in such a manner that the aberration correcting optical system imparts a larger amount of phase at a position farther from a point where the aberration correcting optical system crosses an optical axis of light emitted from the light source. With this, it is possible to increase a tolerance for the center misalignment of the objective lens so as to reduce aberration caused by the center misalignment.

Abstract: An objective lens is a single-lens objective lens both surfaces of which are aspherical. The objective lens has a numerical aperture not less than 0.75, and is made of glass satisfying 1.75<n, and 35<v, where n is a refractive index of the glass for at least one of used wavelengths, and v is an Abbe number for a d-lay. With this arrangement, it becomes possible to provide an objective lens which is downsized, has less aberration, and corrects the aberration easily, without a decline in light utilization efficiency; a method for correcting a manufacturing error thereof; and an optical pick-up device using the objective lens.

Abstract: An objective lens is made up of a light-source-side lens and a medium-side lens wherein at least either one of rim portions of respective opposing surfaces of the light-source-side lens and the medium-side lens forms a rise-up section projected towards the other lens, the rim portion which forms the rise-up section and the rim portion of the other lens at least partially contact one another, and these two lens are fixed together by an adhesive resin layer formed in a spacing between the respective rim portions. With the foregoing structure, an objective lens made up of a pair of lenses which has high rigidity as a whole and is capable of high speed recording and reproducing by suppressing adverse effects of resonance can be realized.

Abstract: A beam shaping element includes a set of diffraction gratings on each surface thereof, in such a manner that intervals between the gratings farer from a vicinity of an optical axis and nearer to a periphery are narrower, wherein each interval between the respective gratings monotonously increases or monotonously decreases along a direction in which each grating-shaped pattern extends. According to the arrangement above, it is possible to correct displacement of a light emitting point of a light source by simply performing a positional adjustment within a plane that is orthogonal to the optical axis. Thus, it is possible to provide the beam shaping element that enables to correct the displacement of the light emitting point of the light source simply by performing positional adjustment in the plane vertical to the optical axis, thereby making it unnecessary to perform positional adjustment along the optical axis direction, and to provide a light source unit and an optical pickup using the beam shaping element.

Abstract: An imaging apparatus reduces the influence of the movement of hands and of the motion of an object on a high resolution picture image. Picture image light from the object passes through an optical system and light-transmitting domains of a color filter provided at the light incident side of an imaging device. The light-transmitting domains transmit only predetermined chromatic lights of the picture image light to input to corresponding photo-receiving domains of the imaging device. The imaging device is a two-picture element mixed reading type device. In a high resolution mode, an image forming point of the picture image light is moved to two places in parallel, and the picture image light is formed at each image forming point to image the picture image light. Then, the signal processing circuit combines the two original picture image signals whose image forming points during the imaging operation are different to generate a single output picture image signal.

Abstract: An objective lens is a single-lens objective lens both surfaces of which are aspherical. The objective lens has a numerical aperture not less than 0.75, and is made of glass satisfying 1.75<n, and 35<v, where n is a refractive index of the glass for at least one of used wavelengths, and v is an Abbe number for a d-lay. With this arrangement, it becomes possible to provide an objective lens which is downsized, has less aberration, and corrects the aberration easily, without a decline in light utilization efficiency; a method for correcting a manufacturing error thereof; and an optical pick-up device using the objective lens.

Abstract: An optical recording medium is an optical disk formed by bonding a substrate to a light transparent cover layer smaller in thickness than the substrate, and the optical disk includes one or more recording layer between the substrate and the light transparent cover layer. The light transparent cover layer is smaller in diameter than the substrate. Further, it is desirable that an outer edge of the substrate be higher than a between-edge part of the substrate. With this arrangement, a bonding surface of the substrate and the light transparent cover layer is not exposed out of an outer curved surface. Accordingly, it is possible to protect the bonding surface between the outer edge and the inner edge so as to increase strength against exfoliation of the light transparent cover layer.

Abstract: An image pick-up apparatus is provided with: a charge-coupled device for picking up imaging light from a subject and forming image data; an image-shift mechanism for shifting the charge-coupled device to a plurality of relative positions with respect to the imaging light so as to allow the charge-coupled device to form the image data at the relative positions; an LPF constituted by a filter for removing a spatial frequency component that appears due to a light-quantity difference between a plurality of pieces of image data generated by the charge-coupled device through the image-shift mechanism; and a memory control section for combining the plurality of image data. With this arrangement, it is possible to suppress a striped pattern due to the light-quantity difference, and consequently to improve the image quality.

Abstract: An image pick-up apparatus is provided with: a charge-coupled device for picking up imaging light from a subject and forming image data; an image-shift mechanism for shifting the charge-coupled device to a plurality of relative positions with respect to the imaging light so as to allow the charge-coupled device to form the image data at the relative positions; an LPF constituted by a filter for removing a spatial frequency component that appears due to a light-quantity difference between a plurality of pieces of image data generated by the charge-coupled device through the image-shift mechanism; and a memory control section for combining the plurality of image data. With this arrangement, it is possible to suppress a striped pattern due to the light-quantity difference, and consequently to improve the image quality.

Abstract: In an optical pickup device, the numerical aperture (NA) of an objective lens is set at 0.7 or more, and the ellipticity of polarized light of a light beam which is incident upon the objective lens is set to be larger than (1.4×NA)−0.7. According to the structure, an optical pickup device which can prevent deterioration of the jitter and crosstalk characteristics, for example, due to oval deformation of a beam spot can be provided.

Abstract: An optical pickup device which includes an objective lens having a numerical aperture of 0.7 or more collects light emitted from a light source and irradiates an optical recording medium. The objective lens and an antireflection film formed thereon are set so that the intensity of light incident on the outermost rim of the objective lens is 45% or more and 80% or less of the intensity of incident light from the light source to the center of the objective lens. According to the configuration, it is possible to provide an optical pickup device including a high NA objective lens which can suppress a reduction in the light amount at the lens rim.

Abstract: Thickness information and refractive index information of a light transmitting layer are recorded in advance on an optical recording medium. Based on the thickness information and the refractive index information of the light transmitting layer, space between two lens units of an objective lens system is adjusted in an optical recording and reproducing apparatus, so that spherical aberration is adjusted. Accordingly, in the optical recording and reproducing apparatus using two lens units, it becomes possible to correctly record or reproduce the information to and from the optical recording medium.

Abstract: In accordance with the present invention a pickup device for optical disks includes spring wires supporting displaceably in focusing and tracking directions a lens holder holding an objective lens. One set of more than two spring wires is provided for each side of the lens holder and a total of two such sets of spring wires are arranged parallel to each other. Of more than two spring wires of each set, at least one spring wire has a cross section allowing a spring constant in the focusing direction and that in the tracking direction to vary from each other and is also positioned farther or closer than the remaining spring wires away or to a centerline of the objective lens. As such the pickup device can ensure a sufficient displacement in the focusing and tracking directions and also control an inclination of the lens holder.