Patents by Inventor Taketoshi Yonezawa

Taketoshi Yonezawa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4991919
    Abstract: This invention provides an optical head apparatus in which a grating coupler (8), which is formed on a circular region which has a center on an axis (18) and has a periodical structure with dents and projections in a configuration of concentric circles or spirals around the axis (18), input-couples laser light (7) emitted from a semiconductor laser (5) and turns it into waveguided light (16B) which transmits in a waveguiding layer (15B). The waveguided light (16B) is converted, in a region where the waveguiding layer (15B) and a waveguiding layer (15A) overlap each other, to waveguided light (16A) which transmits in the waveguiding layer (15A). By a grating coupler (9), formed on a ring-shaped area which is located around the axis (18), which has a periodic structure with dents and projections of a configuration of concentric circles or spirals around the axis (18), the waveguided light (16A) is radiated and focused onto points (FA), (FB) and (FC) which are located on the axis (18).
    Type: Grant
    Filed: October 18, 1989
    Date of Patent: February 12, 1991
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Seiji Nishiwaki, Yoshinao Taketomi, Shinji Uchida, Takaaki Tomita, Taketoshi Yonezawa, Sadao Mizuno
  • Patent number: 4835070
    Abstract: A magnetic recording medium has a non-magnetic substrate, a magnetic layer formed on the surface of the substrate containing a ferromagnetic material, and a protective film formed on the magnetic layer. The protective film is constituted by a singular layer of continuous or dispersed molecular structures in which carbon and an element constituting the magnetic layer are bonded directly or indirectly through oxygen and at least one fluorine is bonded to the carbon. This magnetic recording medium can be produced by a method comprising preparing a substrate of a non-magnetic material, forming a magnetic layer of a ferromagnetic material on the surface of the substrate, and forming, by a plasma CVD method, a protective film of a fluorine-containing molecular body having a thickness not greater than a value equivalent to 5 .ANG. on the surface of the magnetic layer.
    Type: Grant
    Filed: September 4, 1985
    Date of Patent: May 30, 1989
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hideo Kurokawa, Tsutomu Mitani, Kazuo Yokoyama, Taketoshi Yonezawa
  • Patent number: 4833031
    Abstract: A magnetic recording medium is provided with a protective film made of a diamond like carbon film and an organic compound film on a ferromagnetic metal recording film; and it realizes excellent durability and small spacing loss or the like; and as a result high density magnetic recording is obtainable.
    Type: Grant
    Filed: March 19, 1987
    Date of Patent: May 23, 1989
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hideo Kurokawa, Tsutomu Mitani, Masaru Odagiri, Taketoshi Yonezawa
  • Patent number: 4717622
    Abstract: A magnetic recording medium has a protective layer made of high hardness carbon synthesized under a low-temperature and a low-pressure by blowing hydrocarbon gas plasma onto a magnetic recording layer. The resistance thereof is large, and therefore, high density magnetic recording can be realized in a magnetic recording system wherein the magnetic head contacts the magnetic recording medium. Durability of the magnetic recording medium is substantially improved.
    Type: Grant
    Filed: March 11, 1986
    Date of Patent: January 5, 1988
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hideo Kurokawa, Tsutomu Mitani, Taketoshi Yonezawa
  • Patent number: 4645977
    Abstract: A plasma CVD apparatus comprises a first vacuum enclosure with a plasma generating means, an accelerating means for accelerating ions in a plasma toward a substrate and a second vacuum enclosure connected to the first vacuum enclosure, so that the plasma gas flows into the second vacuum enclosure and forms a film of uniform and superior quality at high speed.
    Type: Grant
    Filed: November 29, 1985
    Date of Patent: February 24, 1987
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hideo Kurokawa, Tsutomu Mitani, Taketoshi Yonezawa
  • Patent number: 4636077
    Abstract: Disclosed in an aligning and exposing method suitable for use in the production of LSIs. Coherent ray beams are applied from two directions to form interference fringe through interference of the coherent rays. A diffraction grid is disposed in the optic paths of the ray beams substantially in parallel with the interference fringe. The ray beams reflected and transmitted by the grid are converged by a lens system and the intensities of the ray beams are measured to detect the relative position between the interference fringe formed by two coherent ray beams and the diffraction grid, thereby to permit a highly accurate alignment of fine semiconductor element. The pitch of the grid on the substrate is selected to be n (n being an integer) times as large as the pitch of the interference fringe, so that the grid for alignment purpose is formed simultaneously with the formation of the LSI pattern by photolithographic technic.
    Type: Grant
    Filed: April 12, 1984
    Date of Patent: January 13, 1987
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Noboru Nomura, Koichi Kugimiya, Takayoshi Matsumura, Taketoshi Yonezawa
  • Patent number: 4523102
    Abstract: In a step for bonding a color filter to a solid-state color-image sensor chip with an adhesive which is curable not only by light or more particularly ultraviolet-ray irradiation but also by heating, pre-curing or partial curing is effected by irradiating light rays after the color filter and the chip has been pressed against each other and correctly aligned with each other in a bonding device and then the chip with the partially-bonded color filter is removed from the bonding device and complete curing of the adhesive is accomplished by heating. According to one embodiment of the present invention the bonding step is carried out in an atmosphere containing the oxygen so that the adhesive which has been squeezed out from the space between the color filter and the chip may be prevented from being cured and subsequently removed in a simple manner.
    Type: Grant
    Filed: January 31, 1983
    Date of Patent: June 11, 1985
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Ogawa Kazufumi, Shigeru Kondo, Yoshiko Yasuda, Taketoshi Yonezawa, Isamu Kitahiro
  • Patent number: 4418284
    Abstract: In a step for bonding a color filter to a solid-state image sensor so as to provide a color-sensitive image sensor (to be referred to as "a color-image sensor" in this specification), a method for bonding the color filter to the image sensor with an adhesive which is curable by ultraviolet radiation and also the constructions of color filters and image sensors which can facilitate the bonding step.
    Type: Grant
    Filed: March 11, 1981
    Date of Patent: November 29, 1983
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kazufumi Ogawa, Shigeru Kondo, Yoshiko Yasuda, Taketoshi Yonezawa, Isamu Kitahiro
  • Patent number: 4388128
    Abstract: In a step for bonding a color filter to a solid-state color-image sensor chip with an adhesive which is curable not only by light or more particularly ultraviolet-ray irradiation but also by heating, pre-curing or partial curing is effected by irradiating light rays after the color filter and the chip has been pressed against each other and correctly aligned with each other in a bonding device and then the chip with the partially-bonded color filter is removed from the bonding device and complete curing of the adhesive is accomplished by heating. According to one embodiment of the present invention the bonding step is carried out in an atmosphere containing the oxygen so that the adhesive which has been squeezed out from the space between the color filter and the clip may be prevented from being cured and subsequently removed in a simple manner.
    Type: Grant
    Filed: March 11, 1981
    Date of Patent: June 14, 1983
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kazufumi Ogawa, Shigeru Kondo, Yoshiko Yasuda, Taketoshi Yonezawa, Isamu Kitahiro
  • Patent number: 4358295
    Abstract: A polishing method suitable for use in working a surface of a magnetic material such as materials of magnetic head into a mirror-finished surface. The work is placed in a treating liquid cell such that its surface to be worked is opposed by the surface of a lap. The treating liquid contains fine polishing grains of magnesium oxide as the polishing agent, by an amount less than 4 wt %, and may contain 10 to 30 wt % of glycerol for increasing the viscosity. As a relative movement occurs between the work and the lap, the treating liquid forms a state of a dynamic-pressure bearing between the opposing surfaces of the work and lap, so that the surface of the work is polished into mirror surface by the action of the magnesium oxide without contacting the lap directly.
    Type: Grant
    Filed: March 27, 1980
    Date of Patent: November 9, 1982
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yoshiharu Namba, Taketoshi Yonezawa
  • Patent number: 4238215
    Abstract: A magnetic head having a sputter-deposited glass film of the gap forming area of the magnetic core, said glass film being made of borosilicate glass having the composition consisting of 65-85 mol % of SiO.sub.2, 8-30 mol % of B.sub.2 O.sub.3 and containing 2-15 mol % of alkali metal oxide Na.sub.2 O and K.sub.2 O and 0.1-5 mol % of Al.sub.2 O.sub.3, with the molar ratio of boron oxide to alkali metal oxides being defined by the following formula: ##EQU1## The magnetic head provides sharpness of the recording leakage flux, thus giving excellent electromagnetic conversion characteristics.
    Type: Grant
    Filed: March 30, 1979
    Date of Patent: December 9, 1980
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kazuo Yokoyama, Ryuji Nichiyama, Taketoshi Yonezawa
  • Patent number: 4170032
    Abstract: A magnetic head having a sputter-deposited glass film of the gap forming area of the magnetic core, said glass film being made of borosilicate glass having the composition consisting of 65-85 mol % of SiO.sub.2, 8-30 mol % of B.sub.2 O.sub.3 and containing 2-15 mol % of alkali metal oxide Na.sub.2 O and K.sub.2 O and 0.1-5 mol % of Al.sub.2 O.sub.3, with the molar ratio of boron oxide to alkali metal oxides being defined by the following formula: ##EQU1## The magnetic head provides sharpness of the recording leakage flux, thus giving excellent electromagnetic conversion characteristics.
    Type: Grant
    Filed: September 18, 1978
    Date of Patent: October 2, 1979
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kazuo Yokoyama, Ryuji Nishiyama, Taketoshi Yonezawa
  • Patent number: RE33669
    Abstract: Disclosed .[.in.]. .Iadd.is .Iaddend.an aligning and exposing method suitable for use in the production of LSIs. Coherent ray beams are applied from two directions to form .Iadd.an .Iaddend.interference fringe through interference of the coherent rays. A diffraction grid is disposed in the optic paths of the ray beams substantially in parallel with the interference fringe. The ray beams reflected .[.and.]. .Iadd.or .Iaddend.transmitted by the grid are converged by a lens system and the intensities of the ray beams are measured to detect the relative position between the interference fringe formed by two coherent ray beams and the diffraction grid, thereby to permit a highly accurate alignment of fine semiconductor element. The pitch of the grid on the substrate is selected to be n (n being an integer) times as large as the pitch of the interference fringe, so that the grid for alignment purpose is formed simultaneously with the formation of the LSI pattern by photolithographic technic.
    Type: Grant
    Filed: January 12, 1989
    Date of Patent: August 20, 1991
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Noboru Nomura, Koichi Kugimiya, Takayoshi Matsumura, Taketoshi Yonezawa