Sharp Kabushiki Kaisha Corporation

Kazunori Matsubara

Ayumi Yagi

Tetsuo Ueyama

Shinzoh Murakami

Kazuhiro Tsuchida

Yukio Watanabe

Osamu Miyazaki

Tetsuyoshi Inoue

Nobumasa Kaneko

Keiji Sakai

Katsushige Masui

Masahiro Ikehara

Toshiya Nagahama

Hirotoshi Takemori

Hideshi Koizumi

Hisayuki Shinohara

Shigehiro Yamada

Takashi Itoh

A diffracting portion is disposed in an optical path between a light source and an optical disc. The diffracting portion diffracts the reflected light from recording layers of the optical disc toward a light receiving portion. The diffracting portion includes a first diffraction region having a first diffraction efficiency and a second diffraction region having a second diffraction efficiency lower than the first diffraction efficiency. The first diffraction region includes a FES diffracting portion and first to fourth TES diffracting portions. The second diffraction region includes fifth and sixth TES diffracting portions. First-order diffraction lights from the non-light-collecting recording layer enter on the fifth and the sixth TES diffracting portions, and are diffracted toward the light receiving portion by the fifth and the sixth TES diffracting portions.

Optical pickup apparatus

There is provided an optical pickup apparatus that can obtain a stable servo signal by reducing stray light generated by diffraction in a recording layer other than a recording layer on which light is condensed. A hologram element provided in an optical pickup apparatus for recording information onto a recording medium and/or reproducing information on the recording medium by use of light includes fourth and fifth divisions where at least first-order diffracted light among diffracted light beams obtained by reflection and diffraction on a recording layer other than a light-condensed recording layer on which light is condensed by an objective lens so as not to be directed toward first and second light-receiving elements for detecting focus position information and third to eighth light-receiving elements for detecting track position information.

An optical pickup includes a hologram element. The hologram element is provided with a hologram pattern including a splitting section for focus which splits light used for the detection of an FES and a splitting section for tracking which splits light used for the detection of a TES. The splitting section for tracking is formed in a region excluding a region interposed between a first virtual straight line and a second virtual straight line. The first virtual straight line is drawn on the hologram element in parallel to an X direction and passes through an optical axis of reflected light entering the hologram element in a state where the objective lens is in a neutral position, and the second virtual straight line is drawn in parallel to the first virtual straight line, while being spaced at a distance d from the first virtual straight line.

Optical pickup

To read information from a target information recording surface reliably by canceling DC offsets in tracking-signal detection signals is provided. In effecting tracking servo by 3-beam method, auxiliary light receiving domains D, D, D, Dare provided. The auxiliary light receiving domain receives images formed by the light returned from a different information recording surface from the one targeted for reading. Sub beams of &#xb1; first-order diffracted light enter the light receiving domains D, D, D, D. With respect to the diffraction direction of the hologram, the auxiliary light receiving domains D, D(D, D) are provided on both sides of the light receiving domain D(D). Since signals are computed as: D&#x2212;(D+D); and D&#x2212;(D+D) with the internal connection, DC offsets can be canceled in RES signals (D+D, D+D) used in the DPP method.

Optical pickup device using polarizing hologram element and hologram laser therefor

A semiconductor laser device includes a package having a front surface, a rear surface and an outer peripheral surface; a semiconductor laser element and a light receiving element provided on the front surface; a plurality of leads arranged in spaced relation on the front surface as extending outward from the package; and an optical element supported above the front surface with its optical axis perpendicular to the front surface for guiding a laser beam emitted from the semiconductor laser element toward an object and guiding light reflected on the object to the light receiving element; wherein the outer peripheral surface is configured so as to be fitted in a cylindrical hole having an axis parallel to the optical axis of the optical element, and has a recess extending from the front surface to the rear surface, and the leads are bent as extending from the front surface and passing through the recess with distal portions thereof extending along the optical axis of the optical element and with proximal ends thereof electrically connected to the semiconductor laser element and the light receiving element.

Semiconductor laser device with light receiving element

An optical pick-up apparatus and a semiconductor laser apparatus which can suppress reduction of optical utilization efficiency for the laser light emitted from the semiconductor laser element. When a laser light which is emitted from a laser element for DVD and whose polarization direction is perpendicular to a direction of a groove of the polarization grating is incident on the polarization grating, the polarization grating does not diffract the laser light and transmits the laser light as zero-order diffraction light. Consequently, all of the laser light emitted from the laser element for DVD can be used for reading information signal of DVD and detecting FES and TES. This enables reduction of optical utilization efficiency arising by diffracting action of a grating used for detecting TES of CD in a conventional optical pick-up apparatus to be suppressed.

Optical pick-up apparatus and semiconductor laser apparatus

The present invention provides a semiconductor laser devices of hologram laser type, constructed so that the configuration of the optical elements barely changes even if its package expands due to a rise in temperature or moisture absorption. In the semiconductor laser device, a body frame made of an insulating resin contains a semiconductor laser element, a mirror, a photo-detecting element for reading signals, a mirror-mounting base and a detector-mounting base. Also, a holographic element is mounted on the top of the sidewall of the body frame. The mirror-mounting base and the detector-mounting base are made of a resin, wherein each base is integrally formed with the base plate of the body frame and is separated from the sidewall of the body frame.

Semiconductor laser device and optical pickup device

Silver paste is applied to a stem, and a semiconductor laser chip is mounted onto the stem on which the silver paste has been applied. Next, the semiconductor laser chip mounted on the stem, while kept pressurized toward the stem with a collet, is heated to make the silver paste temporarily cured, by which the semiconductor laser chip is fixed onto the stem. Then, after a temporary curing step, the silver paste is finally cured within a thermostat. The semiconductor laser device thus manufactured is low in thermal resistance and reduced in variations of operating current and prevented from short-circuiting of the semiconductor laser chip.

Semiconductor laser manufacturing method and semiconductor laser

A semiconductor laser device, with which a compact and thin optical pickup can be realized, is provided. On the top surface of a supporting member, there is formed an element mounting area for mounting a series of elements including a semiconductor laser element, and a light detecting element which detects a laser beam emitted from the semiconductor laser element and reflected by a surface of an outside optical disc so as to be re-entered. An optical path from the semiconductor laser element to the surface of the optical disc includes a vertical optical path advancing from the element mounting area of the supporting member in an approximately vertical upward direction. On a pair of right and left opposing ends of the supporting member, arcuate curved outer surfaces are formed, respectively, so as to fit the supporting member into an installation hole, for a semiconductor laser device, having arcuate curved inner surfaces. These curved outer surfaces are formed of arcs having the vertical optical path as the central axes, and are so formed that the curvature radiuses of the right and left arcs are different.

Semiconductor laser device and optical pickup using the same

A semiconductor laser apparatus of the present invention is composed of an insulating framein which at least a semiconductor laser device and a light receiving device are mounted. A plurality of leadspass through each of two opposite facesA,B of the insulating frameand extend from inside to outside of the insulating frame. The insulating framehas external facesA,B that are parallel to a mounting faceon which the semiconductor laser deviceis mounted. According to the present invention, it is possible to provide a semiconductor laser apparatus that has good productivity and that facilitates position adjustment such as optical axis adjustment and an optical pickup apparatus using the same.

Semiconductor laser apparatus and optical pickup apparatus using same

A fine pattern of an optical device formed by the Photo-Polymer method has a groovea side wallof which is sloped against a surface of stamperThe slope angle &#x3b8; of the side wallsatisfies the following relational expression: Tan(4&#xd7;h&#xd7;w)&#x3c;&#x3b8;&#x3c;80&#xb0; where h: a depth of the grooveand w: a width of a top of a projected portion formed by the side walls. Burrs formed in the optical device are reduced, and thereby mass productivity of the optical device is improved.

Stamper, manufacturing method therefor and optical device manufactured therewith

A semiconductor laser device that is suitable for mass production, that permits an improved wire layout, and that permits miniaturization includes leads disposed through each of two side faces of an insulating frame member so as to run from outside to inside the insulating frame member, an LD and a light-receiving element mounted inside the insulating frame member, and wires laid inside the insulating frame member so as to connect the leads to the electrodes of the LD and the light-receiving element. Inside the insulating frame member, the tip of one lead is extended farther inward than the edge of an element mount portion that faces the tip of another lead that is disposed through the same side face of the insulating frame member.

Growing community of inventors

Shiki-gun, Japan

Kazunori Matsubara