Patents by Inventor Hironobu Sai

Hironobu Sai 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: 8963090
    Abstract: Provided is a compact terahertz-wave generating apparatus that generates terahertz waves at high output and high efficiency. A terahertz-wave generating apparatus includes an electromagnetic-wave resonator including a hollow fiber in which an electromagnetic-wave gain medium is disposed, the electromagnetic-wave gain medium generating terahertz waves when exciting energy is supplied thereto, wherein the terahertz waves are amplified in the electromagnetic-wave resonator and are taken from the electromagnetic-wave resonator, wherein the diameter of the hollow fiber is set at one or more times and ten times or less as large as the inside diameter of the hollow fiber, in which the electromagnetic-wave gain medium is disposed, at which a cutoff frequency in a terahertz-wave propagation mode TE11 is provided.
    Type: Grant
    Filed: April 23, 2012
    Date of Patent: February 24, 2015
    Assignee: Canon Kabushiki Kaisha
    Inventor: Hironobu Sai
  • Publication number: 20140084163
    Abstract: Provided is a compact terahertz-wave generating apparatus that generates terahertz waves at high output and high efficiency. A terahertz-wave generating apparatus includes an electromagnetic-wave resonator including a hollow fiber in which an electromagnetic-wave gain medium is disposed, the electromagnetic-wave gain medium generating terahertz waves when exciting energy is supplied thereto, wherein the terahertz waves are amplified in the electromagnetic-wave resonator and are taken from the electromagnetic-wave resonator, wherein the diameter of the hollow fiber is set at one or more times and ten times or less as large as the inside diameter of the hollow fiber, in which the electromagnetic-wave gain medium is disposed, at which a cutoff frequency in a terahertz-wave propagation mode TE11 is provided.
    Type: Application
    Filed: April 23, 2012
    Publication date: March 27, 2014
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: Hironobu Sai
  • Patent number: 7801192
    Abstract: VCSEL array with a structure in which vertical cavity surface emitting devices are arranged on a substrate. The VCSEL array includes first and second optical devices. The second optical device receives light that is directed parallel to the substrate and emitted from the first optical device and converts the light into an electric signal when a voltage applied to the second optical device is switched to a reverse bias. The second optical device emits light that is directed parallel to the substrate when a voltage applied to the second optical device is switched to a forward bias.
    Type: Grant
    Filed: March 19, 2008
    Date of Patent: September 21, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventor: Hironobu Sai
  • Publication number: 20080240185
    Abstract: VCSEL array with a structure in which vertical cavity surface emitting devices are arranged on a substrate. The VCSEL array includes first and second optical devices. The second optical device receives light that is directed parallel to the substrate and emitted from the first optical device and converts the light into an electric signal when a voltage applied to the second optical device is switched to a reverse bias. The second optical device emits light that is directed parallel to the substrate when a voltage applied to the second optical device is switched to a forward bias.
    Type: Application
    Filed: March 19, 2008
    Publication date: October 2, 2008
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: Hironobu Sai
  • Publication number: 20070193622
    Abstract: A laminate type thin-film solar cell which can convert sunlight efficiently into electric power and be formed in multi-laminate structure without limitation in selecting a semiconductor material, and be excellent in conversion efficiency, and a production method therefor are provided. A first photoelectric conversion unit including a first semiconductor lamination portion (1a) made of a semiconductor having a first band gap energy and a first pair of electrodes (13, 14) is provided on a substrate (4), and a second photoelectric conversion unit including a second semiconductor lamination portion (2a) made of a semiconductor having a second band gap energy and a second pair of electrodes (23, 24) is stuck thereon. A third photoelectric conversion unit including a third semiconductor lamination portion (3a) made of a semiconductor having a third band gap energy and a third pair of electrodes (33, 34) may be stuck thereon, and as many conversion units as desired can be stuck.
    Type: Application
    Filed: March 30, 2005
    Publication date: August 23, 2007
    Inventor: Hironobu Sai
  • Patent number: 7173287
    Abstract: A semiconductor light-emitting device is made of a group III-nitride compound semiconductor expressed as AlxGayIn1?x?yN (where 0?x?1, 0?y?1, and 0?x+y?1). The semiconductor light-emitting device includes: a substrate made of SiC; a semiconductor layer which is placed above the substrate and has a light-emitting region; a multi-layered reflective layer which is placed between the substrate and the semiconductor layer and which reflects light produced in the light-emitting region; and a phase matching layer which is placed between the substrate and the multi-layered reflective layer and which reflects light produced in the light-emitting region and matches a phase of light reflected from a lower boundary surface of the multi-layered reflective layer and a phase of light reflected from a lower boundary surface of the substrate among light produced in the light-emitting region.
    Type: Grant
    Filed: August 12, 2005
    Date of Patent: February 6, 2007
    Assignee: Rohm Co., Ltd.
    Inventors: Hironobu Sai, Haruo Tanaka
  • Patent number: 7132351
    Abstract: A method of fabricating a compound semiconductor layer has steps of forming a first layer made of an oxidizable material on a substrate, forming a second layer made of a compound semiconductor on the first layer, oxidizing the first layer made of the oxidizable material to an oxide layer and forming a third layer made of compound semiconductor that constitutes a semiconductor element on the second layer.
    Type: Grant
    Filed: July 23, 2004
    Date of Patent: November 7, 2006
    Assignee: Rohm Co., Ltd.
    Inventor: Hironobu Sai
  • Publication number: 20060054908
    Abstract: A semiconductor light-emitting device is made of a group III-nitride compound semiconductor expressed as AlxGayIn1-x-yN (where 0?x?1, 0?y?1, and 0?x+y?1). The semiconductor light-emitting device includes: a substrate made of SiC; a semiconductor layer which is placed above the substrate and has a light-emitting region; a multi-layered reflective layer which is placed between the substrate and the semiconductor layer and which reflects light produced in the light-emitting region; and a phase matching layer which is placed between the substrate and the multi-layered reflective layer and which reflects light produced in the light-emitting region and matches a phase of light reflected from a lower boundary surface of the multi-layered reflective layer and a phase of light reflected from a lower boundary surface of the substrate among light produced in the light-emitting region.
    Type: Application
    Filed: August 12, 2005
    Publication date: March 16, 2006
    Inventors: Hironobu Sai, Haruo Tanaka
  • Publication number: 20060038184
    Abstract: A light-emitting device includes, in order of mention: a positive hole supply layer; a particle layer comprising particles of semiconductor crystals and a conductive medium, the conductive medium which fills spaces between the particles and confines positive holes and electrons in the particles by dint of an energy gap larger than those of the particles; and an electron supply layer. Positive holes, which are supplied from the positive hole supply layer through the conductive medium to the particles, and electrons, which are supplied from the electron supply layer through the conductive medium to the particles, are caused to recombine to emit light in the particles.
    Type: Application
    Filed: August 12, 2005
    Publication date: February 23, 2006
    Inventor: Hironobu Sai
  • Publication number: 20060023764
    Abstract: In a semiconductor laser according to the present invention, a p-type and n-type semiconductor portion supply positive holes and electrons to a confining layer in a direction perpendicular to a stacking direction of the confining layer, and the p-type and n-type semiconductor portions do not prevent light produced in the confining layer from being emitted by laser oscillation in a stacking direction of intrinsic semiconductor layers. The p-type and n-type semiconductor portion are placed up to a position enough to supply the positive holes and electrons to the confining layer, and supply the positive holes and electrons to the confining layer respectively. As a result, the positive holes and electrons can recombine in the confining layer to produce light.
    Type: Application
    Filed: July 1, 2005
    Publication date: February 2, 2006
    Inventor: Hironobu Sai
  • Publication number: 20060016397
    Abstract: A sample stand is set in a chamber provided with an observation window on its upper surface and a heater for heating a sample is provided in the vicinity of the sample stand. Then, a microscope, a camera and a television monitor are connected and mounted outside the observation window of the chamber. The microscope is mounted such that a specific layer of the sample is focused on and can be observed. According to a manufacturing method of the preset invention, oxidation treatment is performed in such equipment while an oxidation process of the specific layer (semiconductor layer for selective oxidation) of the sample is observed.
    Type: Application
    Filed: September 26, 2005
    Publication date: January 26, 2006
    Inventor: Hironobu Sai
  • Patent number: 6979581
    Abstract: A sample stand is set in a chamber provided with an observation window on its upper surface and a heater for heating a sample is provided in the vicinity of the sample stand. Then, a microscope, a camera and a television monitor are connected and mounted outside the observation window of the chamber. The microscope is mounted such that a specific layer of the sample is focused on and can be observed. According to a manufacturing method of the preset invention, oxidation treatment is performed in such equipment while an oxidation process of the specific layer (semiconductor layer for selective oxidation) of the sample is observed.
    Type: Grant
    Filed: December 13, 2002
    Date of Patent: December 27, 2005
    Assignee: Rohm Co., Ltd.
    Inventor: Hironobu Sai
  • Publication number: 20050098786
    Abstract: In a semiconductor light emitting device including a mesa section having at least a sandwich structure of an n-type clad layer, an active layer and a p-type clad layer which are constituted by compound semiconductor layers formed on a substrate, and an inorganic insulating film 22 formed to cover the mesa section excluding a contact region, the inorganic insulating film is constituted by an inorganic insulating film having a vacancy rate of 50% or more.
    Type: Application
    Filed: September 30, 2003
    Publication date: May 12, 2005
    Inventors: Hironobu Sai, Yoshiaki Oku
  • Patent number: 6856635
    Abstract: A lower multilayer reflection film (2), a light emitting layer forming portion (6) and an upper multilayer reflection film (8) are sequentially formed on a substrate (1) to form a semiconductor laminated portion (9), and a current injection region A is formed at a part of the semiconductor laminated portion so as to emit light from the surface in the center thereof. And, according to the present invention, the current injection region A is formed so as to be deflected from a center of the substrate. As a result, there is provided a surface light emitting type semiconductor laser capable of monitoring a light emitting power correctly and controlling it automatically in order to achieve the constant light emitting power in a case where the surface light emitting type laser chip is used as a light source for a pickup or the like.
    Type: Grant
    Filed: October 22, 2002
    Date of Patent: February 15, 2005
    Assignee: Rohm Co., Ltd.
    Inventors: Hironobu Sai, Jun Ichihara
  • Publication number: 20050020036
    Abstract: A method of fabricating a compound semiconductor layer has steps of forming a first layer made of an oxidizable material on a substrate, forming a second layer made of a compound semiconductor on the first layer, oxidizing the first layer made of the oxidizable material to an oxide layer and forming a third layer made of compound semiconductor that constitutes a semiconductor element on the second layer.
    Type: Application
    Filed: July 23, 2004
    Publication date: January 27, 2005
    Applicant: ROHM CO., LTD.
    Inventor: Hironobu Sai
  • Publication number: 20040155580
    Abstract: It is an object of the present invention to provide a surface light-emitting device that can realize a lightweight and compact-profile optical input/output device with reasonable price, especially the one that emits light. The beam generator 12 comprises a surface light-emitting device having a stacked-layer formed of a cathode 2, a luminescent layer 4 made of organic material(s) and an anode 6 in that order, the stacked-layer being located adjacent to a glass substrate 8. The anode 6 is a transparent electrode that is formed to correspond to a hologram pattern of a condensing lens. When a DC voltage is applied between the cathode 2 and the anode 6 with the DC power source, the luminescent layer 4 illuminate corresponding to the hologram pattern of the condensing lens, and the light will converge to a focal point of the condensing lens. Therefore, the surface light-emitting device can play the both roles of the light source and the condensing lens.
    Type: Application
    Filed: February 4, 2004
    Publication date: August 12, 2004
    Applicant: Rohm Co., Ltd.
    Inventors: Haruo Tanaka, Hironobu Sai
  • Patent number: 6775310
    Abstract: On a semiconductor substrate (1), a double hetero structure portion (6) in which an active layer (4) having smaller band gap is sandwiched between semiconductor layers (3, 5) having larger band gap than that of the active layer (4) is formed. A light reflection film (9) is formed at least a part of side walls of the double hetero structure portion (6). As a result, a semiconductor light emitting device that light which leaks from side wall of light emitting area in a chip is reduced and emission light can be outputted efficiently can be obtained.
    Type: Grant
    Filed: May 23, 2002
    Date of Patent: August 10, 2004
    Assignee: Rohm Co., Ltd.
    Inventors: Hironobu Sai, Jun Ichihara
  • Patent number: 6713787
    Abstract: It is an object of the present invention to provide a surface light-emitting device that can realize a lightweight and compact-profile optical input/output device with reasonable price, especially the one that emits light. The beam generator 12 comprises a surface light-emitting device having a stacked-layer formed of a cathode 2, a luminescent layer 4 made of organic material(s) and an anode 6 in that order, the stacked-layer being located adjacent to a glass substrate 8. The anode 6 is a transparent electrode that is formed to correspond to a hologram pattern of a condensing lens. When a DC voltage is applied between the cathode 2 and the anode 6 with the DC power source, the luminescent layer 4 illuminate corresponding to the hologram pattern of the condensing lens, and the light will converge to a focal point of the condensing lens. Therefore, the surface light-emitting device can play the both roles of the light source and the condensing lens.
    Type: Grant
    Filed: June 18, 2002
    Date of Patent: March 30, 2004
    Assignee: Rohm Co., Ltd.
    Inventors: Haruo Tanaka, Hironobu Sai
  • Publication number: 20030139060
    Abstract: A sample stand is set in a chamber provided with an observation window on its upper surface and a heater for heating a sample is provided in the vicinity of the sample stand. Then, a microscope, a camera and a television monitor are connected and mounted outside the observation window of the chamber. The microscope is mounted such that a specific layer of the sample is focused on and can be observed. According to a manufacturing method of the preset invention, oxidation treatment is performed in such equipment while an oxidation process of the specific layer (semiconductor layer for selective oxidation) of the sample is observed.
    Type: Application
    Filed: December 13, 2002
    Publication date: July 24, 2003
    Inventor: Hironobu Sai
  • Publication number: 20030076864
    Abstract: A lower multilayer reflection film (2), a light emitting layer forming portion (6) and an upper multilayer reflection film (8) are sequentially formed on a substrate (1) to form a semiconductor laminated portion (9), and a current injection region A is formed at a part of the semiconductor laminated portion so as to emit light from the surface in the center thereof. And, according to the present invention, the current injection region A is formed so as to be deflected from a center of the substrate. As a result, there is provided a surface light emitting type semiconductor laser capable of monitoring a light emitting power correctly and controlling it automatically in order to achieve the constant light emitting power in a case where the surface light emitting type laser chip is used as a light source for a pickup or the like.
    Type: Application
    Filed: October 22, 2002
    Publication date: April 24, 2003
    Inventors: Hironobu Sai, Jun Ichihara