Sharp Kabushiki Kaisha Corporation

Sharp Kabushiki Kaisah

Tetsuo Iwaki

Eiji Yamada

Yukio Kurata

Kazuya Kitamura

Chiaki Yamawaki

Toshiaki Harada

Tohru Okuda

Yorishige Ishii

Toshihiro Tamura

Hideo Okada

Masayuki Nishikawa

Takeshi Yamaguchi

Hidetaka Mizumaki

Tazuko Kitazawa

Hitoshi Takeuchi

Taizo Sasada

Yoshinori Kinai

Katsubumi Koyanagi

Kazutaka Abe

Toshihisa Tanaka

A position of a first module () with respect to an optical fiber () is determined in accordance with a receiving efficiency at the first module () with respect to light emitted from the optical fiber (). Power of light coupled into the optical fiber () from the first module () is set in accordance with a value of a far-end reflectivity on a side of the first module () 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.

Method of manufacturing optical communication system

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.

Beam shaping element, and light source unit and optical pickup using same

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&#x3c;d&#x2266;r*D/(n&#x2212;n) when a PD diameter is not larger than D, and within a range of D&#x2266;d&#x2266;r*D/(n&#x2212;n) 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 nis a refractive index of a substance between the spherical end surface and the PD.

Optical communication system

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.

Optical pickup device

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.

Objective lens, method for correcting manufacturing error thereof, and optical pick-up device using the same

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.

Objective lens, optical pickup-device equipped with same and assembling method of same

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. Thereby, an equivalent imaging time in imaging a single output picture image may be shortened.

Imaging apparatus

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.

Optical recording medium having light transparent cover layer smaller in outer diameter than substrate

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.

Image shifting image pickup apparatus using filter for removing spatial frequency component

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&times;NA)&minus;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.

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.

Optical pickup device and optical recording medium

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.

Optical recording medium and optical recording and reproducing apparatus

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.

Pickup device for optical disk

An imaging apparatus includes a solid-state imaging element having a matrix of pixels thereon, an optical series for entering a subject image into the solid-state imaging element, and an image shifting mechanism for relatively shifting the subject image in 2-D with respect to the solid-state imaging element. A control circuit is further included for controlling an operation of the image shifting mechanism. Still further, an image synthesizing circuit is included for synthesizing a plurality of images shifted by the image shifting mechanism, along with a moving amount detecting unit for detecting a moving amount of the subject image on the solid-state imaging element. Finally, the imaging apparatus includes a shift amount generating unit for generating an image shift amount for the subject image first, and thence a correction image shift amount based on the image shift amount and moving amount, based on which the image shifting mechanism shifts the subject image. The above arrangement makes it possible to correct a movement of the subject image formed by the imaging apparatus, thereby realizing a high-resolution image.

A zoom lens including: a first lens array which has positive refractive power and which is in a fixed position relative to an image plane; a second lens array which has negative refractive power and which provides variable power by moving along an optical axis direction; a third lens array which has positive refractive power and which is in a fixed position relative to the image plane; a fourth lens array which has positive refractive power and which is capable of moving along the optical axis direction so as to maintain the image plane, which moves corresponding to movement of the second lens array and an object to be imaged, at a predetermined distance from a reference plane; a fifth lens array which has negative refractive power and which is in a fixed position relative to the image plane; and a sixth lens array which has positive refractive power and which is in a fixed position relative to the image plane. The first to sixth lens arrays are arranged in a first through sixth order, respectively, so that the first lens array lies adjacent to the object to be imaged.

Growing community of inventors

Yamatokoriyama, Japan

Tetsuo Iwaki