Sony Corporation

Kyu Kanno

Jin Sato

Yoshito Ikeda

Seiichi Ogata

Motoo Aiba

Satoshi Kawakita

Takatoshi Yamada

Junichi Honda

Shinji Takahashi

Makoto Watanabe

Seiji Kumagai

Tadashi Saito

Yasuo Sugizaki

Norikatsu Fujisawa

Masayoshi Aoshima

Toshinobu Watanabe

Kumi Takahashi

A diffraction element for diffracting a particular wavelength of incident optical beam includes: a base section made from a first resin and provided with a predetermined diffraction pattern; and a cover section made from a second resin and covering the diffraction pattern, wherein a rate of change of refraction index of the first resin is substantially the same as a rate of change of refraction index of the second resin in a temperature range between a first temperature and a second temperature.

Diffraction element, objective lens unit, optical pickup and optical disc apparatus

The first and second materials of the diffraction element are selected such that the first material's refraction indexes n(&#x3bb;), n(&#x3bb;) and n(&#x3bb;) for the first, second and third wavelengths &#x3bb;and &#x3bb;and the second material's refraction indexes n(&#x3bb;), n(&#x3bb;) and n(&#x3bb;) for the first, second and third wavelengths &#x3bb;and &#x3bb;satisfy one of the conditions (1) or (2).

Diffraction element, objective lens unit, optical pickup, optical disc apparatus and design method for diffraction element

A lens, a light irradiation apparatus and a laser pointer to which the lens is applied to are provided, in which eccentricity, discrepancy of light axes, uneven gap of lens surfaces and the like are reduced without performing positioning of respective lenses; and cost of manufacturing a lens having a plurality of functions can be reduced. A lens according to the present invention is the lens, in which a light diameter expanding element for expanding a diameter of incident light and a light collimating element for projecting approximately collimated light after receiving the incident light having the diameter thereof expanded by the light diameter expanding element are integrally formed in advance as a lens of one unit. According to such lens, it is possible to control occurrence of the eccentricity, the discrepancy of light axes and the uneven gap of lens surfaces due to a positioning discrepancy between respective lenses, in comparison to a lens wherein a lens as the light diameter expanding element and a lens as the light collimating element are individually formed and are combined into one body.

Lens, light irradiation apparatus, and laser pointer

A stationary head type magnetic recording/reproducing system which includes a magnetic head responsible for recording/reproduction of signal to and from a running magnetic tape, and a pair of guides positioned on both sides of the magnetic head, the magnetic head having a flat slide-contact plane which comes into contact with the magnetic tape, and beveled planes at ends thereof.

Stationary head type magnetic recording/reproducing system with flat and bevel slide contact surfaces on transducig head

A magnetic head includes a first magnetic core half having a coil winding groove coupled to a second magnetic core half having an auxiliary core element accommodated in the coil winding groove, such that a magnetic gap is defined between joining faces of the first and second core halves. Alternatively, a composite magnetic head includes a pair of magnetic heads that have magnetic gaps with different azimuth angles from each other and disposed closely in an opposing relationship to each other in a head feeding direction so as to define respective track widths and a track pitch. A thin conductor film is formed on at least one of a pair of opposing faces of the magnetic heads for intercepting leakage fluxes from the magnetic gap of the other magnetic head. The thin conductor film has a thickness and is located such that the track pitch formed by the magnetic heads is substantially independent of the thickness of the thin conductor film. A method of producing a magnetic head includes forming a track width restricting groove on each of a pair of head core blocks. The blocks are fused together with glass when aligned with the restricting groove. An additional groove is formed at an angle substantially equal to the azimuth angle of the magnetic gap on at least one of the pairs of faces on the blocks and the blocks are cut in a direction substantially perpendicular to the bottom face of the additional groove.

Composite magnetic head having thin conductor film

A thin film type magnetic head that electromagnetic conversion efficiency is improved by making gradually magnetic resistance larger with approaching to a magnetic gap can be provided. There is disclosed a magnetic head including a pair of magnetic core half members having nonmagnetic substrates and magnetic metal films formed on the nonmagnetic substrates and a coil formed at a concave part by a thin film forming process, the pair of magnetic core half members being jointed to each other opposite to each other through a magnetic gap formed between the respective magnetic metal films, the concave part formed on the surface formed by joining at least one of the magnetic metal films and the other magnetic metal film, wherein assistant cores consisting of magnetic materials are joined on the side of the surface by joining a pair of nonmagnetic substrates and the magnetic metal films are formed connected with the assistant cores.

Magnetic head

A magnetic head reduces a slant of a magnetic head chip in comparison with a conventional case. The magnetic head is produced by a manufacturing method. A ridge on a back surface side of a magnetic chip is brought into contact with a chip attachment surface of a chip attachment base. A height of the magnetic head chip is adjusted by using the ridge as a fulcrum.

Growing community of inventors

Miyagi, Japan

Kyu Kanno