Sharp Kabushiki Kaisha Corporation

Nobuo Ogata

Yasuo Nakata

Hideaki Sato

Yoshihiro Sekimoto

Yukio Kurata

Sumito Nishioka

Ikuo Nakano

Kunio Kojima

Tomoyuki Miyake

Yoshio Yoshida

Toshiharu Inui

Toshiyuki Tanaka

Hiroshi Fuji

Takahiro Miyake

Tetsuo Ueyama

Shinji Suminoe

Mitsuru Hineno

Chiaki Kiyooka

Shigemi Maeda

Hiroyuki Yamamoto

Jun Akiyama

Toshiya Ishio

Kohji Minami

Mitsuo Ishii

Katsuhiro Kubo

Hiroshi Katayama

Makoto Horiyama

Etsuji Minami

Tomio Mashiyama

Hideaki Satou

Teruaki Inoue, Deceased

Kazuko Inoue

Takayuki Inoue

Kenji Ikeda

Teruaki Inoue

A surface light-emitting unit of the present invention is an LED module () for emitting light from an LED chip () of a light-emitting element part () via a light flux control section () of a light flux control part (), the light flux control section () being fixed by a plurality of columnar sections () above a fixing surface of a substrate () on which fixing surface the light-emitting element part ()is fixed. This provides an appropriate gap between the light-emitting element part () and the light flux control section () for heat release.

Surface light-emitting unit and display device provided with the same

A surface-emission unit to prevent irregularity in brightness from being generated is provided. The surface-emission unit is composed of light-emission element parts each having a light-emission element, aligned and arranged on a substrate two-dimensionally, and optical lenses each arranged on the substrate with respect to each light-emission element part, to diffuse light from the light-emission element, and a support part to fix the optical lens onto the substrate is arranged so as not overlap a line connecting the light-emission element part corresponding to the optical lens fixed by the support part, to another light-emission element part adjacent to the light-emission element part.

Surface-emission unit and method for producing the same

An optical pickup includes: a first projector for projecting a first light beam of a first wavelength so as to record and reproduce information with respect to an optical disk having a first light transmissive layer; a second projector for projecting a second light beam of a second wavelength longer than the first wavelength so as to record and reproduce information with respect to an optical disk having a second light transmissive layer; an objective lens common to the first and second light beams; and a diffraction optical element made of a lens with a diffraction grating and a refracting face and disposed in an optical path between the first and second projectors and the objective lens. The diffraction optical element is set to satisfy a predetermined equation. As a result, an optical pickup is realized that uses a single focusing means to focus light beams of different wavelengths, so as to record and reproduce information with respect to different kinds of optical disks (recording media) respectively having light transmissive layers of different thicknesses and respectively using different optimum wavelengths of light for reproducing.

Optical pickup

An aberration detection device of the present invention is such that an absolute value of detection sensitivity of an aberration error signal is increased, and variation in detection sensitivity of the aberration error signal is little even when displacement between the center of light beam dividing means and the center of a bundle of light beams occurs due to a shift of a condensing optical system at the time of tracking control. A hologram element () divides light beams reflected from an information storage medium into at least two positive first order diffracted light beams. The hologram element () has a line (D) extending in a radial direction and passing through an optical axis (OZ) and a division line (D) having segments at least both ends thereof and a bulge in a center thereof, wherein the segments are substantially parallel to the line (D), and the bulge () bulges toward the periphery of the hologram element () so that a top (D) of the bulge () is substantially parallel to the line (D).

Aberration detection device and optical pickup device provided with same

An optical integrated unit includes a semiconductor laser (), a polarized light beam splitter (), a light receiving element (), and a polarized light diffraction element () for diffracting an optical beam () and returning light. The polarized light diffraction element () is so provided as to receive the light beam () having passed through a polarized light beam splitter surface (), and as to diffract the returning light such that an optical path of the returning light is changed to lead to the light receiving element (). This makes it possible to provide (i) an optical integrated unit in which the beam diameter of light incidenting on a diffraction element is large and in which an optical path length from the diffraction element to a light receiving element is long, and (ii) an optical pickup device including such an optical integrated unit.

Optical integrated unit and optical pickup device including same

Optical pickup that uses light sources with different wavelengths for each of multiple recording mediums

A recording and reproducing apparatus of the present invention includes a photo-detector having light receiving sections divided along the track direction of an optical disk. The apparatus also includes a wobble signal processing circuit for generating a wobbling polarity judging signal used in judging a wobbling polarity of a track being tracked by comparing phases of a first wobble signal detected from a difference signal of the outputs of the light receiving sections and a second wobble signal detected from a sum signal of the outputs of the light receiving signals. Consequently, whether the wobbled side wall of the track being tracked is the inner or outer radius of track can be judged in real time by a simple structure using one laser beam.

Recording medium with judging area for track area identification based on wobbling polarity

An optical pickup includes a semiconductor laser for emitting light at a wavelength &#x3bb;and a semiconductor laser for emitting light at a different wavelength &#x3bb;from the wavelength &#x3bb;The light at the wavelength &#x3bb;transmitted through an objective lens forms a light-collecting spot on an optical disk to record/reproduce information thereon. The light at the wavelength &#x3bb;transmitted through the objective lens forms a light-collecting spot on an optical disk to record/reproduce information thereon, the two optical disks having different substrate thicknesses. Between the semiconductor laser and the objective lens is there provided a combination-type diffractive element fabricated by combining two raw materials having different refractive index behaviors in relation to wavelength at a combining plane shaped as a grating. The structure facilitates good recording/reproduction on the two types of recording media irrespective of the reproduction wavelengths or substrate thicknesses of the recording media.

An optical recording medium is arranged such that respective information recorded on lands and grooves are reproducible by either of a light beam of a first wavelength &#x3bb;and a light beam of a second wavelength &#x3bb;which is shorter than the first wavelength &#x3bb;. The groove depth d of the optical recording medium is such that tracking error signals of not less than a predetermined level can be ensured for respective wavelengths &#x3bb;and &#x3bb;without generating distortion in waveform, irrespectively of differences in receiving light sensitivity of a photodetector provided in a optical pickup devices for use in recording and reproducing information on and from such optical recording medium.

Optical recording medium and optical pickup device

In an optical recording medium, a groove G and/or a land L composing a recording track includes an interrupted portion of a predetermined length in a direction of the recording track, and the interrupted portion is a clock mark to obtain a clock signal. When (clock mark length C )/(beam spot size D )&equals;CM, CM&lE;1.0. This reduces a region to record the control signal, thereby enabling high-density recording and reproduction, reproducing a control signal having a waveform free from distortion, and generating a clock signal in a state of little jitter.

Optical recording medium, optical recording and reproducing device, and recording and reproducing method for the optical recording medium

Beam shaping means may have a shaping ratio set to allow a light beam emitted from a semiconductor laser and having an elliptic intensity distribution to have an ellipticity of no more than two to obtain a spot achieving high light availability and reduced in size. Furthermore, the shaping ratio can be set to no more than 2.5 to allow a polalized-beam splitter (light separation means) and other components to be arranged in a converged flux passing between the semiconductor laser and a collimator lens.

Optical pickup device

A light spot detects a focus offset amount based on an amount of variation of a focus error signal when a light spot passes a boundary between a land section and a groove section adjacent to the land section on an optical disk. Specifically, an amount of variations in the focus error signal at a center of a land section at a time the light spot passes the boundary between the land and the groove adjacent to the land is detected as a focus offset amount, and an amount of variation in the focus error signal at a center of the groove section is detected as a focus offset amount for the groove sections, thereby providing an optical information recording/reproducing device which permits recording/reproducing information on and from a tracking area of an optical disk under just-in-focus conditions without increasing a cost of the device nor being affected by an error due to changes over time or variations in optical disks.

Optical information recording/reproducing apparatus having focus error signal compensation

Growing community of inventors

Nara, Japan

Nobuo Ogata