Patents by Inventor Yoshitaka Tomomura
Yoshitaka Tomomura 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).
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Patent number: 9625121Abstract: A headlamp 1 includes (i) a laser element 2 for emitting a laser beam, (ii) a light emitting section 4, including a sealing material made from an inorganic material, for emitting fluorescence upon receiving the laser beam emitted from the laser element 2, and (iii) a heat sink 7 for releasing, via a contact surface of the heat sink 7 which contact surface is in contact with the light emitting section 4, heat generated in the light emitting section 4 in response to the laser beam emitted onto the light emitting section 4, the light emitting section 4 existing within a range which is determined on the basis of the contact surface and with which desired heat releasing efficiency is obtained.Type: GrantFiled: November 15, 2011Date of Patent: April 18, 2017Assignee: SHARP KABUSHIKI KAISHAInventors: Yasuo Fukai, Yoshiyuki Takahira, Koji Takahashi, Yosuke Maemura, Yoshitaka Tomomura
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Patent number: 8823258Abstract: A fluorescent material-sealed sheet includes a plurality of fluorescent sections, an upper sealing section, and a lower sealing section, the plurality of fluorescent sections being sealed by the upper sealing section and the lower sealing section.Type: GrantFiled: March 14, 2013Date of Patent: September 2, 2014Assignee: Sharp Kabushiki KaishaInventors: Tatsuya Ryowa, Yoshitaka Tomomura, Makoto Izumi, Kazunori Annen, Masato Ohno
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Publication number: 20130249388Abstract: A fluorescent material-sealed sheet includes a plurality of fluorescent sections, an upper sealing section, and a lower sealing section, the plurality of fluorescent sections being sealed by the upper sealing section and the lower sealing section.Type: ApplicationFiled: March 14, 2013Publication date: September 26, 2013Applicant: SHARP KABUSHIKI KAISHAInventors: Tatsuya RYOWA, Yoshitaka TOMOMURA, Makoto IZUMI, Kazunori ANNEN, Masato OHNO
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Publication number: 20120140504Abstract: A headlamp 1 includes (i) a laser element 2 for emitting a laser beam, (ii) a light emitting section 4, including a sealing material made from an inorganic material, for emitting fluorescence upon receiving the laser beam emitted from the laser element 2, and (iii) a heat sink 7 for releasing, via a contact surface of the heat sink 7 which contact surface is in contact with the light emitting section 4, heat generated in the light emitting section 4 in response to the laser beam emitted onto the light emitting section 4, the light emitting section 4 existing within a range which is determined on the basis of the contact surface and with which desired heat releasing efficiency is obtained.Type: ApplicationFiled: November 15, 2011Publication date: June 7, 2012Applicant: SHARP KABUSHIKI KAISHAInventors: Yasuo Fukai, Yoshiyuki Takahira, Koji Takahashi, Yosuke Maemura, Yoshitaka Tomomura
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Publication number: 20120106185Abstract: A headlamp of the present invention includes: a laser diode for emitting a laser beam with coherence; and a light emitting section which, upon irradiation with the laser beam from the laser diode, emits light so that the light is outputted from the light emitting device. The headlamp further includes an excitation light output prevention member for preventing the laser beam from the laser diode from being outputted from the headlamp while the laser beam maintains coherence.Type: ApplicationFiled: October 25, 2011Publication date: May 3, 2012Applicant: SHARP KABUSHIKI KAISHAInventors: Katsuhiko KISHIMOTO, Yoshitaka Tomomura, Hidenori Kawanishi
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Publication number: 20110280033Abstract: A headlamp includes: a laser diode for emitting laser beam; a light-emitting section for emitting light when irradiated with the laser beam emitted from the laser diode; and a cooling device for cooling the light-emitting device by use of a fluid. With the arrangement, it is possible to prevent an increase in temperature of the light-emitting section which is irradiated with excitation light, and thereby to realize a light source of long lifetime.Type: ApplicationFiled: May 13, 2011Publication date: November 17, 2011Applicant: SHARP KABUSHIKI KAISHAInventors: Katsuhiko KISHIMOTO, Koji Takahashi, Yoshitaka Tomomura, Hidenori Kawanishi
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Publication number: 20110248624Abstract: A headlamp 1 includes: laser diodes 2 that emit excitation light; and a light emitting part 5 that emits light upon receiving the excitation light emitted from the laser diodes 2, the light emitting part 5 containing a first fluorescent material and a second fluorescent material, the first fluorescent material having its emission spectrum peak in a range of not less than 500 nm but not more than 520 nm, the second fluorescent material having an emission spectrum peak which is different from the emission spectrum peak of the first fluorescent material. In a spectrum of the light emitted from the light emitting part 5, a luminous intensity at the emission spectrum peak of the first fluorescent material is higher than a luminous intensity in an emission spectrum covering a range of not less than 540 nm but not more than 570 nm. This allows the headlamp 1 to emit illumination light which achieves a high visibility of an irradiation target at least in a dark place.Type: ApplicationFiled: April 6, 2011Publication date: October 13, 2011Applicant: SHARP KABUSHIKI KAISHAInventors: Katsuhiko Kishimoto, Yuji Yokosawa, Yoshitaka Tomomura
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Patent number: 6358822Abstract: A method of manufacturing a compound semiconductor is provided which can produce a mixed crystal layer with high nitrogen content without lowering the crystallinity when a III-V compound semiconductor layer including nitrogen and at least another V group element is grown by molecular beam epitaxy.Type: GrantFiled: February 7, 2000Date of Patent: March 19, 2002Assignee: Sharp Kabushiki KaishaInventor: Yoshitaka Tomomura
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Patent number: 5786269Abstract: A II-VI group compound semiconductor device having a p-type Zn.sub.x Mg.sub.1-x S.sub.y Se.sub.1-y (0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1) semiconductor layer, on which an electrode layer is formed with at least metallic nitride layer lying between the semiconductor layer and the electrode layer.Type: GrantFiled: September 24, 1996Date of Patent: July 28, 1998Assignee: Sharp Kabushiki KaishaInventors: Masanori Murakami, Yasuo Koide, Nobuaki Teraguchi, Yoshitaka Tomomura
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Patent number: 5767536Abstract: A II-VI group compound semiconductor device comprising a Zn.sub.X Mg.sub.1-X S.sub.Y Se.sub.1-Y (0.ltoreq.X.ltoreq.1, 0.ltoreq.Y.ltoreq.1) semiconductor layer, an intermediate layer comprising a compound of an element constituting the semiconductor layer and an additive element of Cd, Te or Hg formed on the semiconductor layer, and an electrode layer containing Ni, Pt or Pd formed on the intermediate layer.Type: GrantFiled: November 25, 1996Date of Patent: June 16, 1998Assignee: Sharp Kabushiki KaishaInventors: Masanori Murakami, Yasuo Koide, Nobuaki Teraguchi, Yoshitaka Tomomura
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Patent number: 5747827Abstract: An optoelectronic semiconductor device is provided in which carrier transport towards the active region thereof is enhanced by the formation of a miniband within a superlattice region of the device having a repeating pattern of first and second semiconductor regions. The minimum energy level of the miniband is equal to or greater than the energy level of a guiding region between the active region and the superlattice region.Type: GrantFiled: March 7, 1996Date of Patent: May 5, 1998Assignee: Sharp Kabushiki KaishaInventors: Geoffrey Duggan, Nobuaki Teraguchi, Judy Megan Rorison, Yoshitaka Tomomura
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Patent number: 5616937Abstract: A compound semiconductor luminescent device is disclosed which comprises a semiconductor substrate and a multi-layered structure disposed on the substrate, the multi-layered structure comprising at least one conductive layer, a luminescent layer, and a current injection layer, wherein the substrate and the layers are made of at least one kind of II-VI group compound semiconductor.Type: GrantFiled: July 30, 1991Date of Patent: April 1, 1997Assignee: Sharp Kabushiki KaishaInventors: Masahiko Kitagawa, Yoshitaka Tomomura
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Patent number: 5587609Abstract: A II-VI group compound semiconductor device having a p-type Zn.sub.x Mg.sub.1-x S.sub.y Se.sub.1-y (0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1) semiconductor layer, on which an electrode layer is formed with at least metallic nitride layer lying between the semiconductor layer and the electrode layer.Type: GrantFiled: March 23, 1995Date of Patent: December 24, 1996Assignee: Sharp Kabushiki KaishaInventors: Masanori Murakami, Yasuo Koide, Nobuaki Teraguchi, Yoshitaka Tomomura
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Patent number: 5554877Abstract: An electroluminescent device of compound semiconductor includes a compound semiconductor substrate having at least one through-hole, an electroluminescent part consisting of a plurality of epitaxial compound semiconductor layers formed on the substrate, and at least a pair of electrodes having external leads in which one electrode is connected to the uppermost layer of the electroluminescent part and another electrode is directly connected to the lowest layer of the electroluminescent part through the through-hole of the substrate. Thereby, a voltage from an external source is enabled to be directly applied to the electroluminescent part.Type: GrantFiled: September 2, 1992Date of Patent: September 10, 1996Assignee: Sharp Kabushiki KaishaInventors: Masahiko Kitagawa, Yoshitaka Tomomura
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Patent number: 5508522Abstract: A method for fabricating a semiconductor thin film is disclosed. The method includes the step of epitaxially growing a semiconductor layer made of a group II-VI compound semiconductor to have a thickness of at least one atomic layer or more, on a main plane of a single-crystal semiconductor substrate, the semiconductor substrate having one of a diamond structure and a zinc blende structure, the main plane being inclined by an angle in the range of 2 to 16 degrees with respect to a (100) plane.Type: GrantFiled: December 17, 1993Date of Patent: April 16, 1996Assignee: Sharp Kabushiki KaishaInventors: Kenji Nakanishi, Masahiko Kitagawa, Yoshitaka Tomomura, Shinya Hirata
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Patent number: 5416884Abstract: A semiconductor waveguide structure of the II-VI group compound semiconductor made of the II group element and the VI group element. The waveguide structure includes a waveguide layer and clad layers which puts the waveguide layer therebetween. The waveguide layer has a refractive index larger than a refractive index of each clad layer. At least one of the clad layers contains the element Cd. With such an arrangement, the refractive index of one clad layer is established to be different from that of the other clad layer. In such a case, it is preferable that the semiconductor waveguide structure comprises at least two waveguide layers which are adjacent to each other and that the structure has either one of the features as follows: each refractive index of the waveguide layers varies stepwise at each boundary surface of the layers; the refractive index of at least one of the waveguide layers varies so as to be inclined; and super lattice layers are formed between the clad layer and the waveguide layers.Type: GrantFiled: May 18, 1994Date of Patent: May 16, 1995Assignee: Sharp Kabushiki KaishaInventors: Shinya Hirata, Masahiko Kitagawa, Yoshitaka Tomomura
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Patent number: 5270614Abstract: A luminescent material capable of emitting a blue-green light with high luminance, which comprises a single crystalline sulfide solid solution of cubic or hexagonal system represented by the formula: Zn.sub.1-(x+y) Cd.sub.y Al.sub.x S, wherein x and y satisfy 0.001.ltoreq.x<0.1, 0<y.ltoreq.0.5, respectively.Type: GrantFiled: April 29, 1992Date of Patent: December 14, 1993Assignee: Sharp Kabushiki KaishaInventors: Masahiko Kitagawa, Yoshitaka Tomomura, Kenji Nakanishi
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Patent number: 5237182Abstract: An electroluminescent device of compound semiconductor including a semiconductor substrate, a buffer layer epitaxially grown on the semiconductor substrate and a luminescent layer epitaxially grown on the buffer layer, the substrate being formed from a single crystal of zinc sulfide, zinc selenide or a mixed crystal thereof, the luminescent layer being formed from aluminum nitride, indium nitride, gallium nitride or a mixed crystal of at least two of the nitrides.Type: GrantFiled: November 26, 1991Date of Patent: August 17, 1993Assignee: Sharp Kabushiki KaishaInventors: Masahiko Kitagawa, Yoshitaka Tomomura, Kenji Nakanishi
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Patent number: 5204283Abstract: A high-purity II-VI semiconducting compound can be produced by initially preparing a substrate of a II-VI semiconducting compound by a chemical transport method with a halogen as transport medium and then epitaxially growing a layer of a II-VI compound on this substrate.Type: GrantFiled: August 20, 1991Date of Patent: April 20, 1993Assignee: Sharp Kabushiki KaishaInventors: Masahiko Kitagawa, Yoshitaka Tomomura
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Patent number: 5198690Abstract: An electroluminescent device of compound semiconductor which is made of II-IV compound semiconductor to be in pn junction type, wherein n layer of the pn junction part comprises a II-VI compound semiconductor layer containing comprises a II-VI compound semiconductor layer containing zinc as an essential composite element and p layer of the pn junction part comprises a II-VI compound semiconductor layer having an epitaxial layer containing M, Be and Te (wherein M is Cd or Zn) as an essential composite element.Type: GrantFiled: November 25, 1991Date of Patent: March 30, 1993Assignee: Sharp Kabushiki KaishaInventors: Masahiko Kitagawa, Yoshitaka Tomomura, Kenji Nakanishi