Patents by Inventor Koichi Nitta

Koichi Nitta 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: 20030214616
    Abstract: An image display device including a light emission section which emits light to an intensity adjusting section and a wavelength conversion section which change the intensity and wavelength of the emitted light. Phosphors and phosphor like materials are employed in wavelength conversion and a liquid crystal is employed for the light adjustment. The light emission device may include plural semiconductor light emitting elements having a different wavelength ranges such as diodes stacked in a compact and predetermined order such that wavelengths of light from each diode are emitted from the light emitting elements.
    Type: Application
    Filed: May 13, 2003
    Publication date: November 20, 2003
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Satoshi Komoto, Masayuki Ishikawa, Tadashi Umeji, Kuniaki Konno, Koichi Nitta, Haruhiko Okazaki
  • Publication number: 20030205714
    Abstract: There are provided a semiconductor light emitting device wherein the variation in tone in each device is small and the variation in tone due to deterioration with age is also small, and a method for manufacturing the same. The semiconductor light emitting device includes an active layer for emitting primary light having a first wavelength by current injection, and a light emitting layer excited by the primary light for emitting secondary light having a second wavelength different from said first wavelength, wherein the primary light and the secondary light are mixed to be outputted.
    Type: Application
    Filed: April 17, 2003
    Publication date: November 6, 2003
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hideto Sugawara, Koichi Nitta, Hirohisa Abe, Kuniaki Konno, Yasuo Idei
  • Publication number: 20030197191
    Abstract: For the purpose of enhancing the light extracting efficiency, improving the production yield and elongating the lifetime of a semiconductor light emitting element or a semiconductor light emitting device using the element, a semiconductor light emitting element comprises: a light emitting layer that emits light; and a substrate transparent to the light emitted from the light emitting layer. The substrate defines a top surface supporting the light emitting layer thereon; a bottom surface opposed to the top surface and side surfaces connecting the top surface and the bottom surface. Each of the side surfaces is composed of first side surface extending from the top surface toward the bottom surface, second side surface extending from the first side surface toward the bottom surface, and third side surface extending from the second side surface toward the bottom surface.
    Type: Application
    Filed: March 13, 2003
    Publication date: October 23, 2003
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Koichi Nitta, Takafumi Nakamura, Kuniaki Konno, Yasuhiko Akaike, Yoshiki Endo, Katsufumi Kondo
  • Patent number: 6586874
    Abstract: An image display device including a light emission section which emits light to an intensity adjusting section and a wavelength conversion section which change the intensity and wavelength of the emitted light. Phosphors and phosphor like materials are employed in wavelength conversion and a liquid crystal is employed for the light adjustment. The light emission device may include plural semiconductor light emitting elements having a different wavelength ranges such as diodes stacked in a compact and predetermined order such that wavelengths of light from each diode are emitted from the light emitting elements.
    Type: Grant
    Filed: May 18, 1998
    Date of Patent: July 1, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Satoshi Komoto, Masayuki Ishikawa, Tadashi Umeji, Kuniaki Konno, Koichi Nitta, Haruhiko Okazaki
  • Patent number: 6576933
    Abstract: There are provided a semiconductor light emitting device wherein the variation in tone in each device is small and the variation in tone due to deterioration with age is also small, and a method for manufacturing the same. The semiconductor light emitting device includes an active layer for emitting primary light having a first wavelength by current injection, and a light emitting layer excited by the primary light for emitting secondary light having a second wavelength different from said first wavelength, wherein the primary light and the secondary light are mixed to be outputted.
    Type: Grant
    Filed: March 9, 2001
    Date of Patent: June 10, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideto Sugawara, Koichi Nitta, Hirohisa Abe, Kuniaki Konno, Yasuo Idei
  • Patent number: 6548834
    Abstract: A semiconductor light emitting element is proposed that improves a light extraction efficiency without requiring any complicated processes and techniques. The semiconductor light emitting element includes an active layer for emitting first light by current injection, and a light absorbing and emitting section for absorbing a part of the first light and for emitting second light having a greater peak wavelength than the first light. A difference in peak wavelength between the first light and the second light is in a range in which a spectrum of a mixture of the first and second light maintains a unimodal characteristic or is smaller than 0.9 times a half width of the spectrum of the first light.
    Type: Grant
    Filed: January 25, 2002
    Date of Patent: April 15, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideto Sugawara, Koichi Nitta, Ryo Saeki, Katsufumi Kondo, Masanobu Iwamoto
  • Publication number: 20030062530
    Abstract: Efficiency of leading out light released from an active layer, i.e. the external quantum efficiency, can be improved remarkably by processing a light lead-out surface to have an embossment. A layer containing a p-type dopant like magnesium (Mg) is deposited near the surface of a p-type GaN layer to diffuse it there, and a p-side electrode is made on the p-type GaN layer after removing the deposited layer. This results in ensuring ohmic contact with the p-side electrode, preventing exfoliation of the electrode and improving the reliability.
    Type: Application
    Filed: October 25, 2002
    Publication date: April 3, 2003
    Applicant: KABUSHIKI KAISHA TOSHIBA.
    Inventors: Haruhiko Okazaki, Koichi Nitta, Chiharu Nozaki
  • Publication number: 20020190262
    Abstract: A light emitting device includes a plurality of chips efficiently disposed in a limited space of an opening that has an approximately elliptical or elongate-circular opening shape. The device includes a lead having a slit formed between a portion for bonding a wire to and a portion for mounting chips on, thereby to prevent extrusion of an adhesive and eliminate defective bonding.
    Type: Application
    Filed: April 8, 2002
    Publication date: December 19, 2002
    Inventors: Koichi Nitta, Kenji Shimomura, Hiroaki Oshio, Takeshi Komatsu
  • Patent number: 6495862
    Abstract: Efficiency of leading out light released from an active layer, i.e. the external quantum efficiency, can be improved remarkably by processing a light lead-out surface to have an embossment. A layer containing a p-type dopant like magnesium (Mg) is deposited near the surface of a p-type GaN layer to diffuse it there, and a p-side electrode is made on the p-type GaN layer after removing the deposited layer. This results in ensuring ohmic contact with the p-side electrode, preventing exfoliation of the electrode and improving the reliability.
    Type: Grant
    Filed: December 20, 1999
    Date of Patent: December 17, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Haruhiko Okazaki, Koichi Nitta, Chiharu Nozaki
  • Publication number: 20020163302
    Abstract: A light emitting device, free from change of color even when the wavelength of a light emitting element shifts, includes a light emitting element (106) for emitting primary light having an intensity peak at a wavelength shorter than 400 nm; a silicone resin (111) provided to embed the light emitting element; and a fluorescent element (110) contained in the silicone resin to absorb the primary light and release visible light.
    Type: Application
    Filed: April 8, 2002
    Publication date: November 7, 2002
    Inventors: Koichi Nitta, Hiroaki Oshio, Kenji Shimomura, Tomokazu Kitajima, Nozomu Takahashi, Yuji Takahashi, Toshiya Uemura, Koichi Ota
  • Publication number: 20020139984
    Abstract: A semiconductor light emitting element is proposed that improves a light extraction efficiency without requiring any complicated processes and techniques. The semiconductor light emitting element includes an active layer for emitting first light by current injection, and a light absorbing and emitting section for absorbing a part of the first light and for emitting second light having a greater peak wavelength than the first light. A difference in peak wavelength between the first light and the second light is in a range in which a spectrum of a mixture of the first and second light maintains a unimodal characteristic or is smaller than 0.9 times a half width of the spectrum of the first light.
    Type: Application
    Filed: January 25, 2002
    Publication date: October 3, 2002
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hideto Sugawara, Koichi Nitta, Ryo Saeki, Katsufumi Kondo, Masanobu Iwamoto
  • Publication number: 20020088985
    Abstract: A semiconductor light emitting element, semiconductor light emitting device or image display device includes a wavelength converter for converting a wavelength into another, optical reflector having a wavelength selectivity and a light absorber having a wavelength selectivity, which are disposed in a predetermined positional relation, to prevent external leakage of primary light and to extract secondary light made by wavelength-converting the primary light with a very high efficiency. By using a semiconductor light emitting element for ultraviolet emission, or by combining it with a fluorescent material or any other appropriate material having a wavelength converting function, various kinds of applications, such as illuminator, having a remarkably long-life light source can be made. The semiconductor light emitting element preferably has a emission wavelength near 330 nm, and preferably uses BGaN in its light emitting layer.
    Type: Application
    Filed: October 23, 2001
    Publication date: July 11, 2002
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Satoshi Komoto, Koichi Nitta, Nobuhiro Suzuki, Kuniaki Konno, Hideto Sugawara, Chisato Furukawa
  • Patent number: 6417020
    Abstract: An electrode of a metal, which is one of Group IV and VI elements, is deposited on an n-type InxAlyGa1−x−yN layer. Alternatively, after an electrode material of carbon, germanium), selenium, rhodium, tellurium, iridium, zirconium, hafnium, copper, titanium nitride, tungsten nitride, molybdenum or titanium silicide, is deposited on an n-type InxAlyGa1−x−yN layer or a p-type InxAlyGa1−x−yN layer, an impurity for increasing the carrier concentration of the semiconductor layer is ion-implanted, and the annealing is carried out. Thus, it is possible to provide a light emitting semiconductor device, which has a low contact resistance and a sufficient bond strength to the InxAlyGa1−x−yN layer while maintaining the crystallinity of the InxAlyGa1−x−yN layer.
    Type: Grant
    Filed: July 2, 2001
    Date of Patent: July 9, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koichi Nitta, Haruhiko Okazaki, Tokuhiko Matsunaga
  • Publication number: 20020079506
    Abstract: A semiconductor light emitting element, semiconductor light emitting device or image display device includes a wavelength converter for converting a wavelength into another, optical reflector having a wavelength selectivity and a light absorber having a wavelength selectivity, which are disposed in a predetermined positional relation, to prevent external leakage of primary light and to extract secondary light made by wavelength-converting the primary light with a very high efficiency. By using a semiconductor light emitting element for ultraviolet emission, or by combining it with a fluorescent material or any other appropriate material having a wavelength converting function, various kinds of applications, such as illuminator, having a remarkably long-life light source can be made. The semiconductor light emitting element preferably has a emission wavelength near 330 nm, and preferably uses BGaN in its light emitting layer.
    Type: Application
    Filed: October 24, 2001
    Publication date: June 27, 2002
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Satoshi Komoto, Koichi Nitta, Nobuhiro Suzuki, Kuniaki Konno, Hideto Sugawara, Chisto Furukawa
  • Publication number: 20020053681
    Abstract: In a light emitting element using nitride compound semiconductors, an active layer made of a mixed crystal containing In additionally contains at least Al or B as a component of the mixed crystal to improve the thermal resistance of the crystal and the reliability of the element characteristics. Thus, the semiconductor light emitting element has a sufficient lifetime and permits the emission wavelength to be freely selected from a wider wavelength range including blue, green and orange.
    Type: Application
    Filed: November 2, 2001
    Publication date: May 9, 2002
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hideto Sugawara, Koichi Nitta
  • Patent number: 6359292
    Abstract: In a light emitting element using nitride compound semiconductors, an active layer made of a mixed crystal containing In additionally contains at least Al or B as a component of the mixed crystal to improve the thermal resistance of the crystal and the reliability of the element characteristics. Thus, the semiconductor light emitting element has a sufficient lifetime and permits the emission wavelength to be freely selected from a wider wavelength range including blue, green and orange.
    Type: Grant
    Filed: March 3, 1999
    Date of Patent: March 19, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideto Sugawara, Koichi Nitta
  • Publication number: 20020030197
    Abstract: There are provided a semiconductor light emitting device wherein the variation in tone in each device is small and the variation in tone due to deterioration with age is also small, and a method for manufacturing the same. The semiconductor light emitting device includes an active layer for emitting primary light having a first wavelength by current injection, and a light emitting layer excited by the primary light for emitting secondary light having a second wavelength different from said first wavelength, wherein the primary light and the secondary light are mixed to be outputted.
    Type: Application
    Filed: March 9, 2001
    Publication date: March 14, 2002
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hideto Sugawara, Koichi Nitta, Hirohisa Abe, Kuniaki Konno, Yasuo Idei
  • Patent number: 6340824
    Abstract: A light emitting device or image display includes a fluorescent material as a wavelength converter for converting a wavelength into another. The fluorescent material is disposed in a predetermined positional relation, to prevent external leakage of primary light and to extract secondary light made by wavelength-converting the primary light with a very high efficiency. By using a semiconductor light emitting element for ultraviolet emission and combining it with a fluorescent material or any other appropriate material having a wavelength converting function, various kinds of applications, such as illuminator, having a remarkably long-life light source can be made. The semiconductor light emitting element preferably has a emission wavelength near 330 nm, and preferably uses BGaN in its light emitting layer.
    Type: Grant
    Filed: August 31, 1998
    Date of Patent: January 22, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Satoshi Komoto, Koichi Nitta, Nobuhiro Suzuki, Kuniaki Konno, Hideto Sugawara, Chisato Furukawa
  • Publication number: 20010038103
    Abstract: An electrode of a metal, which is one of Group IV and VI elements, is deposited on an n-type InxAlyGa1-x-yN layer. Alternatively, after an electrode material of carbon, germanium), selenium, rhodium, tellurium, iridium, zirconium, hafnium, copper, titanium nitride, tungsten nitride, molybdenum or titanium silicide, is deposited on an n-type InxAlyGa1-x-yN layer or a p-type InxAlyGa1-x-yN layer, an impurity for increasing the carrier concentration of the semiconductor layer is ion-implanted, and the annealing is carried out. Thus, it is possible to provide a light emitting semiconductor device, which has a low contact resistance and a sufficient bond strength to the InxAlyGa1-x-yN layer while maintaining the crystallinity of the InxAlyGa1-x-yN layer.
    Type: Application
    Filed: July 2, 2001
    Publication date: November 8, 2001
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Koichi Nitta, Haruhiko Okazaki, Tokuhiko Matsunaga
  • Patent number: D471166
    Type: Grant
    Filed: October 2, 2001
    Date of Patent: March 4, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroaki Oshio, Kenji Shimomura, Koichi Nitta