Patents by Inventor Hitoshi Murofushi

Hitoshi Murofushi 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).

  • Publication number: 20060076565
    Abstract: In a semiconductor light emitting element, multiple bosses having a cylindrical shape and dispersed like islands, and recesses are formed on the upper surface of a window layer. A contact electrode is formed on the upper surface of the bosses. A transparent dielectric film is formed in the recesses. A transparent conductor film is formed on the transparent dielectric film and the contact electrode.
    Type: Application
    Filed: September 20, 2005
    Publication date: April 13, 2006
    Inventors: Hitoshi Murofushi, Shiro Takeda
  • Publication number: 20060001032
    Abstract: An LED comprises a semiconductor region including an active layer for generating light. An anode is arranged centrally on one of the opposite major surfaces of the semiconductor region from which is emitted the light. A reflective metal layer is bonded to the other major surface of the light-generating semiconductor region via an ohmic contact layer. Sufficiently thin to permit the passage of light therethrough, the ohmic contact layer is formed in an open-worked pattern to leave exposed part of the second major surface of the semiconductor region. A transparent, open-worked anti-alloying layer is interposed between the light-generating semiconductor region and the reflective metal layer, covering that part of the second major surface of the light-generating semiconductor region which is left exposed by the ohmic contact layer. The anti-alloying layer prevents the light-generating semiconductor region and reflective metal layer from alloying during heat treatments conducted in the curse of LED manufacture.
    Type: Application
    Filed: September 8, 2005
    Publication date: January 5, 2006
    Inventors: Hitoshi Murofushi, Hidekazu Aoyagi, Shiro Takeda, Yoshihiko Uchida
  • Publication number: 20050205886
    Abstract: An LED comprising a light-generating semiconductor region having an active layer sandwiched between two confining layers of opposite conductivity types. A cathode is arranged centrally on one of the opposite major surfaces of the semiconductor region from which is emitted the light. An array of discrete gold regions are formed via transition metal regions on the other major surface of the semiconductor region at which is exposed one of the confining layers which is of n-type AlGaInP semiconductor material. The gold is thermally diffused into the confining layer via the transition metal regions at a temperature less than the eutectic point of gold and gallium, thereby creating an array of ohmic contact regions of alloyed or intermingled gold and gallium, which are less absorptive of light than their conventional counterparts, to a thickness of 20 to 1000 angstroms.
    Type: Application
    Filed: May 23, 2005
    Publication date: September 22, 2005
    Applicant: Sanken Electric Co., Ltd.
    Inventors: Hitoshi Murofushi, Shiro Takeda
  • Publication number: 20050139842
    Abstract: Provided between a window layer and a protection layer is a light transmissive layer having a refraction index which is between the refraction indexes of the window layer and protection layer. The refraction index n2 of the light transmissive layer is, for example, within ±20% of the geometric average of the refraction indexes of the window layer and protection layer. The thickness T of the light transmissive layer satisfies {(?/4n2)×(2m+1)?(?/8n2)?T?(?/4n2)×(2m+1)+(?/8n2)} where ? represents the wavelength of emitted light and m represents a positive integer not smaller than 0.
    Type: Application
    Filed: December 27, 2004
    Publication date: June 30, 2005
    Applicant: Sanken Electric Co., Ltd.
    Inventors: Hitoshi Murofushi, Shiro Takeda
  • Publication number: 20050110037
    Abstract: A light emitting diode has a semiconductor region for production of light. The semiconductor region is a lamination of two complementary layers, an n-type semiconductor layer, an active layer, a p-type semiconductor layer, another complementary layer, and an ohmic contact layer, in that order from a first major surface of the semiconductor layer, from which the light is emitted, toward a second. A reflective metal layer covers the second major surface of the semiconductor region via a transparent layer for reflecting the light that has traveled through the transparent layer from the semiconductor region. The transparent layer serves to prevent the semiconductor region and the reflective layer from alloying by heat treatments during the manufacture of the LED.
    Type: Application
    Filed: November 12, 2004
    Publication date: May 26, 2005
    Inventors: Shiro Takeda, Hitoshi Murofushi
  • Patent number: 5814838
    Abstract: An LED is disclosed which has a laminated semiconductor body with an anode and a cathode formed on a pair of opposite faces thereof. Among the layers of the semiconductor body are an active layer of AlGaInP semiconductor material, an n type cladding layer of either n type AlGaInP or n type AlInP semiconductor material on one side of the active layer, and a p type cladding layer of p type AlGaInP or p type AlInP semiconductor material on another side of the active layer. Unlike the conventional belief that the active layer should be as free as possible from the infiltration of Zn used in the p type cladding layer as an impurity to determine its p conductivity type, and hence as high in crystallinity as possible, Zn is positively doped into the active layer with a concentration of 1.times.10.sup.16 -5.times.10.sup.17 cm.sup.-3.
    Type: Grant
    Filed: May 15, 1997
    Date of Patent: September 29, 1998
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Koji Ohtsuka, Hitoshi Murofushi, Emiko Chino, Tetsuji Moku