Patents by Inventor Takayoshi Anan
Takayoshi Anan 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).
-
POSITIVE ELECTRODE FOR NON-AQUEOUS ELECTROLYTE BATTERY AND NON-AQUEOUS ELECTROLYTE SECONDARY BATTERY
Publication number: 20150125732Abstract: To provide a positive electrode for non-aqueous electrolyte battery free from internal short circuit and large in charging and discharging capacity. A positive electrode for non-aqueous electrolyte battery includes a positive electrode collector, a coated film of a positive electrode active material formed on the collector, an non-uniform area formed along an end portion of the coated film, in which a thickness of the positive active material changes, and protruding insulators erected on the non-uniform area and a part of a surface of the collector adjacent to the non-uniform area. The protruding insulators erected on a surface of the non-uniform area are mutually independent and disposed at an arrangement density low enough to allow transfer of a battery reactive material through the surface of the non-uniform area.Type: ApplicationFiled: May 22, 2013Publication date: May 7, 2015Applicant: NEC ENERGY DEVICES, LTD.Inventors: Tomoyuki Ohta, Akio Ukita, Takayoshi Anan -
Patent number: 7974328Abstract: The present invention provides a surface-emission type semiconductor laser wherein an effective length of a cavity is reduced, thereby enabling to realize a higher-speed direct modulation. In the surface-emission type semiconductor laser according to the present invention, when supposing the optical path length (L) of a resonator part relative to a lasing wavelength ?0 to be given as 0.9×?0?L?1.1×?0, and denoting the refractive indexes of a high refractive index layer and a low refractive index layer of a dielectric DBR by nH1 and nL1; the average refractive index within an optical path length ?0/4 in the semiconductor in contact with the dielectric DBR by nS1; and the refractive indexes of the high refractive index layer and the low refractive index layer of a semiconductor DBR by nH2 and nL2, respective materials to be used are selected so as to satisfy the following conditions (1) and (2): nH1>f(nS1)nL12+g(nS1)nL1+h(nS1),??(1) where f(nS1)=0.0266 nS12?0.2407 nS1+0.6347; g(nS1)=?0.0508 nS12+0.Type: GrantFiled: March 14, 2008Date of Patent: July 5, 2011Assignee: NEC CorporationInventors: Naofumi Suzuki, Masayoshi Tsuji, Takayoshi Anan, Kenichiro Yashiki, Hiroshi Hatakeyama, Kimiyoshi Fukatsu, Takeshi Akagawa
-
Patent number: 7940828Abstract: An optical communication system for performing data transmission with optical signals comprises a first optical transmitter and a first optical receiver. The first optical transmitter has a first surface-emitting laser including an active layer of a multiple quantum well structure having a quantum well layer of InxGa1-xAs (0.15?x?0.35), the first surface-emitting laser having an oscillation wavelength ranging from 1000 nm to 1100 nm inclusive. The first optical transmitter transmits an optical signal generated by the first surface-emitting laser. The first optical receiver is connected to the first optical transmitter by a first optical transfer path, and receives the optical signal transmitted from the first optical transmitter through the first optical transfer path.Type: GrantFiled: December 27, 2006Date of Patent: May 10, 2011Assignee: NEC CorporationInventors: Masayoshi Tsuji, Hiroshi Hatakeyama, Kimiyoshi Fukatsu, Takayoshi Anan, Naofumi Suzuki, Kenichiro Yashiki
-
Patent number: 7881358Abstract: A surface emitting laser is provided with a first multilayer Bragg reflecting mirror including a first layer, a second multilayer Bragg reflecting mirror including a second layer, and an optical resonator unit that is held between these multilayer Bragg reflecting mirrors and includes an active layer. Further, the optical resonator unit contacts with the first layer and second layer respectively. The effective refraction index neff of the resonator unit is larger than either the first layer or the second layer, and an optical length neffL of the optical resonator unit has a relationship with an oscillating wavelength ? of the surface emitting laser to satisfy the following relationship: 0.5?<neffL?0.7?.Type: GrantFiled: December 18, 2007Date of Patent: February 1, 2011Assignee: NEC CorporationInventors: Takayoshi Anan, Naofumi Suzuki, Kenichiro Yashiki, Masayoshi Tsuji, Hiroshi Hatakeyama, Kimiyoshi Fukatsu, Takeshi Akagawa
-
Publication number: 20100034233Abstract: The present invention provides a surface-emission type semiconductor laser wherein an effective length of a cavity is reduced, thereby enabling to realize a higher-speed direct modulation. In the surface-emission type semiconductor laser according to the present invention, when supposing the optical path length (L) of a resonator part relative to a lasing wavelength ?0 to be given as 0.9×?0?L?1.1×?0, and denoting the refractive indexes of a high refractive index layer and a low refractive index layer of a dielectric DBR by nH1 and nL1; the average refractive index within an optical path length ?0/4 in the semiconductor in contact with the dielectric DBR by nS1; and the refractive indexes of the high refractive index layer and the low refractive index layer of a semiconductor DBR by nH2 and nL2, respective materials to be used are selected so as to satisfy the following conditions (1) and (2): nH1>f(nS1)nL12+g(nS1)nL1+h(nS1),??(1) where f(nS1)=0.0266 nS12?0.2407 nS1+0.6347; g(nS1)=?0.0508 nS12+0.Type: ApplicationFiled: March 14, 2008Publication date: February 11, 2010Inventors: Naofumi Suzuki, Masayoshi Tsuji, Takayoshi Anan, Kenichiro Yashiki, Hiroshi Hatakeyama, Kimiyoshi Fukatsu, Takeshi Akagawa
-
Publication number: 20100020835Abstract: A surface emitting laser is provided with a first multilayer Bragg reflecting mirror including a first layer, a second multilayer Bragg reflecting mirror including a second layer, and an optical resonator unit that is held between these multilayer Bragg reflecting mirrors and includes an active layer. Further, the optical resonator unit contacts with the first layer and second layer respectively. The effective refraction index neff of the resonator unit is larger than either the first layer or the second layer, and an optical length neffL of the optical resonator unit has a relationship with an oscillating wavelength ? of the surface emitting laser to satisfy the following relationship: 0.5?<neffL?0.7?.Type: ApplicationFiled: December 18, 2007Publication date: January 28, 2010Inventors: Takayoshi Anan, Naofumi Suzuki, Kenichiro Yashiki, Masayoshi Tsuji, Hiroshi Hatakeyama, Kimiyoshi Fukatsu, Takeshi Akagawa
-
Publication number: 20090080488Abstract: A surface emitting laser including a semiconductor substrate, a semiconductor substrate, a first reflector formed on the semiconductor substrate, an active layer formed on the first reflector, a tunnel junction layer formed above a part of the active layer, a semiconductor spacer layer which covers the tunnel junction layer, a second reflector formed on the semiconductor spacer layer in a region above the tunnel junction layer, a first electrode formed in the periphery of the second reflector on the semiconductor spacer layer, and a second electrode electrically connected to a layer lower than the active layer, wherein a layer thickness of the semiconductor spacer layer in the region directly above the tunnel junction layer is thinner than the layer thickness of the semiconductor spacer layer in the region directly below the first electrode.Type: ApplicationFiled: September 24, 2008Publication date: March 26, 2009Applicant: NEC CORPORATIONInventors: Hiroshi HATAKEYAMA, Naofumi SUZUKI, Kenichiro YASHIKI, Takeshi AKAGAWA, Takayoshi ANAN, Masayoshi TSUJI, Kimiyoshi FUKATSU
-
Publication number: 20090028201Abstract: An optical communication system for performing data transmission with optical signals comprises a first optical transmitter and a first optical receiver. The first optical transmitter has a first surface-emitting laser including an active layer of a multiple quantum well structure having a quantum well layer of InxGa1-xAs (0.15?x?0.35), the first surface-emitting laser having an oscillation wavelength ranging from 1000 nm to 1100 nm inclusive. The first optical transmitter transmits an optical signal generated by the first surface-emitting laser. The first optical receiver is connected to the first optical transmitter by a first optical transfer path, and receives the optical signal transmitted from the first optical transmitter through the first optical transfer path.Type: ApplicationFiled: December 27, 2006Publication date: January 29, 2009Applicant: NEC CORPORATIONInventors: Masayoshi Tsuji, Hiroshi Hatakeyama, Kimiyoshi Fukatsu, Takayoshi Anan, Naofumi Suzuki, Kenichiro Yashiki
-
Publication number: 20080317476Abstract: A vehicle-mounted optical communication system, which uses an optical signal to perform data transmission, comprises a first optical transmitter and an optical receiver. The first optical transmitter, which is mounted on a vehicle, has a multiple quantum well structure, in which an active layer has a quantum well layer of InxGa1-xAs (where 0.15?x?0.35), and includes a first surface emitting laser the oscillation wavelength of which is between 1000 nm and 1100 nm inclusive. The first optical transmitter transmits an optical signal generated by the first surface emitting laser. The optical receiver, which is mounted on the vehicle and connected to the first optical transmitter via a first optical transmission path, receives the optical signal, which was transmitted by the first optical transmitter, via the first optical transmission path.Type: ApplicationFiled: December 28, 2006Publication date: December 25, 2008Applicant: NEC CORPORATIONInventors: Masayoshi Tsuji, Hiroshi Hatakeyama, Kimiyoshi Fukatsu, Takayoshi Anan, Naofumi Suzuki, Kenichiro Yashiki
-
Publication number: 20080232418Abstract: A surface emitting laser includes a substrate, a first Bragg reflector layer formed on the substrate, an active layer formed on the first Bragg reflector layer and having a light-emitting region, a second Bragg reflector layer formed on the active layer to emit light from the surface in the direction of the optical axis (Z), and a light-scattering member for extracting light from the surface of the second Bragg reflector layer in a direction intersecting the optical axis. With this arrangement, the intensity of light emitted from the surface emitting laser in one direction can be monitored by a simple structure.Type: ApplicationFiled: January 24, 2005Publication date: September 25, 2008Inventor: Takayoshi Anan
-
Publication number: 20080089376Abstract: To provide such a technique as to solve problems about a high operating voltage, temperature rise due to heat generation, in-plane non-uniform injection, and a small modulation bandwidth upon high-speed modulation in a surface-emitting laser. A current confining structure according to the present invention includes an n-type semiconductor layer 102, a current confining layer 106, a current-diffusion preventing layer 103, an active layer 104, and a p-type semiconductor layer 105, which are laminated in order on an n-type semiconductor substrate 101. The current confining layer 106 is composed of a current carrying layer 106b and a current blocking layer 106a. The current-diffusion preventing layer 103 includes an n-type or undoped dilute nitrogen-based compound semiconductor layer containing 0.1% or more of nitrogen.Type: ApplicationFiled: September 8, 2005Publication date: April 17, 2008Inventor: Takayoshi Anan