Patents by Inventor Tatsushi Igarashi

Tatsushi Igarashi 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: 5763999
    Abstract: A light source device in which the radiated light from the dielectric barrier discharge lamp can always be stabilized even if the discharge vessel of the dielectric barrier discharge lamp is large or the load on the tube wall within the discharge vessel is small. This is achieved according to the invention by the provision of a light source device having a discharge lamp which has a generally cylindrical, coaxial double-tube arrangement of an outer tube and an inner tube, in which there is an outer electrode on the outer tube, in which there is an inner electrode on the inner tube, and in which a discharge space between the inner and outer tubes is filled with a discharge gas for formation of excimer molecules by a dielectric barrier discharge, and of a power source for operating this discharge lamp in accordance with the relationship: Vs/Vp.ltoreq.0.5 where Vs is the starting voltage and Vp is the voltage applied to the discharge lamp during steady-state luminous operation.
    Type: Grant
    Filed: September 20, 1995
    Date of Patent: June 9, 1998
    Assignee: Ushiodenki Kabushiki Kaisha
    Inventors: Hiromitsu Matsuno, Nobuyuki Hishinuma, Masashi Okamoto, Tatsushi Igarashi, Fumitoshi Takemoto
  • Patent number: 5757132
    Abstract: To maintain the relative positional relationship between an inner tube and an inner electrode of a dielectric barrier discharge tube having a roughly cylindrical, double tube arrangement of an outer tube coaxially arranged about an inner tube with a discharge space defined therebetween, an outer electrode on an outer surface of the outer tube, an inner electrode on an inner surface of the inner tube, and a discharge gas which forms excimer molecules by a dielectric barrier discharge filling said discharge space, despite repeated expansion and contraction of the inner electrode due to the dielectric barrier discharge lamp being repeatedly turned on and off, according to the invention, the inner electrode is formed of a substantially tubular metal component or the like, and a motion preventing component is provided at opposite ends of the inner electrode for maintaining an axial position of the inner electrode relative to the inner tube.
    Type: Grant
    Filed: October 2, 1996
    Date of Patent: May 26, 1998
    Assignee: Ushiodenki Kabushiki Kaisha
    Inventors: Hiromitsu Matsuno, Nobuyuki Hishinuma, Kenichi Hirose, Kunio Kasagi, Fumitoshi Takemoto, Yoshinori Aiura, Tatsushi Igarashi
  • Patent number: 5739636
    Abstract: A cadmium discharge lamp which can emit line spectra with wavelengths of 214.+-.2 nm with high power is achieved by encapsulating metallic cadmium, in an amount producing a pressure in stationary lighting operation in the range from 2 kPa to 13.7 kPa, together with at least one of the rare gases xenon, krypton, argon and neon, in a temperature-controlled arc tube which is provided with electrodes located adjacently opposite one another, and by operating the lamp such that J/P is in the range from 1.4 to 75, where J is the discharge current in stationary lighting operation in amperes and the P is the cadmium pressure in stationary lighting operation.
    Type: Grant
    Filed: January 22, 1996
    Date of Patent: April 14, 1998
    Assignee: Ushiodenki Kabushiki Kaisha
    Inventors: Akiyasu Yamaguchi, Yukio Yasuda, Hiromitsu Matsuno, Tatsushi Igarashi
  • Patent number: 5666026
    Abstract: A dielectric barrier discharge lamp having a generally cylindrical double-tube arrangement of an outer tube coaxially disposed about an inner tube, with an outer electrode disposed on an outside surface of the outer tube, an inner electrode disposed on an inside surface of the inner tube, and a discharge space provided between the outer tube and the inner tube which is filled with a discharge gas for formation of excimer molecules by dielectric barrier discharge achieves firm engagement of the inner electrode against the inner tube and a stable discharge over a long time even if part of the electrode corrodes due to the ozone produced or it wears. This is achieved by embodiments in which the inner electrode is a generally tubular part which is slit in an axial direction along the full length thereof. The tubular part can be a single cylindrically sheet having opposite longitudinally extending edges spaced from each other by a gap or overlapped.
    Type: Grant
    Filed: September 20, 1995
    Date of Patent: September 9, 1997
    Assignee: Ushiodenki Kabushiki Kaisha
    Inventors: Hiromitsu Matsuno, Nobuyuki Hishinuma, Kenichi Hirose, Kunio Kasagi, Fumitoshi Takemoto, Yoshinori Aiura, Tatsushi Igarashi
  • Patent number: 5589735
    Abstract: An emission device which operates a cadmium lamp with a light intensity sufficient for used in industrial applications is achieved by an emission device having a cadmium lamp with a fluorescent tube within which a cathode and an anode are space a small distance apart and a buffer gas for easier initiation of luminous operation and metallic cadmium in an amount per unit volume of the fluorescent tube of 1.times.10.sup.-4 g/cm.sup.3 to 3.times.10.sup.-3 g/cm.sup.3 are encapsulated, and a power source device for supplying an electrical input between the cathode and the anode in an electrical input range from 0.5 kW to 5.0 kW with the condition:6.03+2.79 W.ltoreq.r.ltoreq.40being satisfied, where the electrical input of the power source device into the cadmium lamp in steady-state luminous operation is W (kW) and the maximum inside radius of the fluorescent tube is r (mm).
    Type: Grant
    Filed: July 25, 1995
    Date of Patent: December 31, 1996
    Assignee: Ushiodenki Kabushiki Kaisha
    Inventors: Akiyasu Yamaguchi, Yukio Yasuda, Tsuneo Okanuma, Tatsushi Igarashi, Hiromitsu Matsuno, Tatsumi Hiramoto
  • Patent number: 5581152
    Abstract: In a dielectric barrier discharge lamp, in which a discharge vessel, in which a discharge gas forming "excimer" molecules is encapsulated, is provided with a dielectric provided with a netlike electrode and a window, through which the light goes, the first object of the invention is achieved by an arrangement in which a thickness of ends of the above-described netlike electrodes is greater than the average thickness of the entire electrode. Another object of the invention is achieved by an arrangement in which a holder incorporated in the discharge vessel has an outer dimension that is less than/equal to an outer dimension of the netlike electrodes. A further object of the invention is achieved by an arrangement by which the discharge vessel has a hollow cylindrical shape formed from an external tube and an internal tube and a means for hermetic sealing is arranged inside the internal tube.
    Type: Grant
    Filed: September 8, 1994
    Date of Patent: December 3, 1996
    Assignee: Ushiodenki Kabushiki Kaisha
    Inventors: Hiromitsu Matsuno, Tatsushi Igarashi, Tatsumi Hiramoto, Fumitoshi Takemoto, Nobuyuki Hishinuma, Yasuo Oonishi, Kunio Kasagi, Takashi Asahina, Yasuhiko Wakahata
  • Patent number: 5542867
    Abstract: A process for connecting a molybdenum foil to a lead portion with sufficient strength and reliability in which an expensive binder, such as platinum, platinum clad molybdenum, or the like, is not used. According to the invention, a carbon containing or carbon coated molybdenum part is placed between the molybdenum foil and the molybdenum lead portion and then the two are resistance welded to one another. Furthermore, a hermetically enclosed part of a lamp can be produced by this process.
    Type: Grant
    Filed: December 7, 1994
    Date of Patent: August 6, 1996
    Assignee: Ushiodenki Kabushiki Kaisha
    Inventors: Nobuyuki Hishinuma, Kenichi Hirose, Tatsushi Igarashi
  • Patent number: 5541481
    Abstract: A cadmium rare gas discharge lamp of the short arc type that has a high power of the spectra in a wavelength range of 210 nm to 230 nm and a stable lamp voltage in lighting operation for a long period. An arc tube 1 is provided within which are disposed opposed, spaced apart electrodes 2, 3 and thermal insulation films 6, 7. A rare gas is encapsulated together with metal cadmium and a quartz glass is used for the material of the arc tube whose OH radical has a weight content of no more than 200 ppm. Electrodes 4 and 5 are spaced apart no more than 10 mm, so that with a lamp current at least 20 amperes, an arc of the electrode-stable type is formed and radiant light of Cd ions obtained. For the encapsulated rare gas, in one embodiment at least one of the rare gases neon, argon or krypton, are used and are encapsulated at a gas pressure of 35 kPa to 2.5 MPa at a standard temperature of 25.degree. C. The arc tube 1 is formed of quartz glass, electrodes 2 and 3 are placed opposite one another.
    Type: Grant
    Filed: July 29, 1994
    Date of Patent: July 30, 1996
    Assignee: Ushiodenki Kabushiki Kaisha
    Inventors: Akiyasu Yamaguchi, Yukio Yasuda, Hiromitsu Matsuno, Tatsushi Igarashi
  • Patent number: 5510158
    Abstract: An oxidation process for an article to be treated in which, by generating ozone with a high concentration, a high treatment rate is achieved. In particular, an oxygen-containing fluid is irradiated with a vacuum ultraviolet rays emitted from a dielectric barrier discharge lamp in which xenon gas is encapsulated, producing a photochemical reaction from which ozone and an activated oxygen result. By causing this ozone and activated oxygen to contact the surface of the article to be treated, the surface of the article is oxidized. An even higher treatment rate can be achieved by generating the activated oxygen with the simultaneous use of a far ultraviolet ray source, thereby increasing the activity of the activated oxygen. Advantageously, the oxidation of the article to be treated with the vacuum ultraviolet rays and far ultraviolet rays is performed in accordance with the relationship:(p.times.d)/(1+I.sup.1/2)=0.33where I is a radiation density (mW/cm.sup.
    Type: Grant
    Filed: November 28, 1994
    Date of Patent: April 23, 1996
    Assignee: Ushiodenki Kabushiki Kaisha
    Inventors: Tatsumi Hiramoto, Tatsushi Igarashi, Hiromitsu Matsuno, Takeo Matsushima, Shinichi Iso
  • Patent number: 5481159
    Abstract: A discharge lamp uses resonance lines which are emitted by ions in an excitation state and has a high short wave ultraviolet ray output. The lamp is provided with a pair of electrodes, having a reciprocal spacing of equal to or smaller than 12 mm, and is of the electrode-stable type. As the major emission material, cadmium is encapsulated in a quantity permitting a partial pressure P in operation of 3.times.10.sup.3 Pa to 1.3.times.10.sup.5 Pa. The lighting operation is performed in a state in which a lamp current J.sub.L fulfills the following condition (a):0.7<J.sub.L /P.sup.1/4 <15.0. Condition (a)As an alternate major emission material, zinc can be encapsulated in a quantity permitting a partial pressure P in operation of 1.times.10.sup.3 Pa to 0.3.times.10.sup.5 Pa ant the lighting operation is performed in a state in which a lamp current J.sub.L fulfills the following condition (b):0.7<J.sub.L /P.sup.1/4 <16.9.
    Type: Grant
    Filed: May 4, 1994
    Date of Patent: January 2, 1996
    Assignee: Ushiodenki Kabushiki Kaisha
    Inventors: Tatsumi Hiramoto, Tatsushi Igarashi, Hiromitsu Matsuno, Yukio Yasuda, Akiyasu Yamaguchi
  • Patent number: 5471278
    Abstract: A cadmium/inert gas discharge lamp of the short arc type, which suppresses an unnecessary emission upstream and downstream of the necessary emission spectra in a wavelength range of 210 to 230 nm, achieves a high efficiency of the emission spectra in the range 210 to 230 nm and can be used in very satisfactory manner for industrial applications. Also, a highly efficient projection exposure device through the incorporation of a cadmium/rare gas discharge lamp of the short arc type having good emission spectrum characteristics in the wavelength range 210 to 230 nm, which can transmit in projecting manner fine image patterns with a large depth of focus. The cadmium/rare gas discharge lamp of the short arc type is arranged within a temperature-regulated quartz bulb, and is provided with a pair of adjacently facing electrodes, together with inert gas selected from xenon, krypton, argon, neon or mixtures of them.
    Type: Grant
    Filed: November 19, 1993
    Date of Patent: November 28, 1995
    Assignees: Ushiodenki Kabushiki Kaisha, Kabushiki Kaisha Nikon
    Inventors: Yukio Yasuda, Akiyasu Yamaguchi, Tatsushi Igarashi, Yasuo Oonishi, Kenzo Kai, Masanori Sugihara, Takashi Mori, Akira Miyaji
  • Patent number: 5444331
    Abstract: A dielectric barrier discharge lamp has a discharge vessel having a discharge chamber filled with a discharge gas. Excimer molecules are developed due to a dielectric barrier discharge. The discharge vessel is equipped with a window for the output of the light radiated from the excimer molecules. A getter space, equipped with a getter, communicates with the discharge chamber. A common wall separates the discharge chamber from the getter space, or a separately arranged getter space is connected to the discharge chamber via a tube. In one form, the discharge vessel and window is made of quartz glass containing less than 10 ppm of OH radicals by weight.
    Type: Grant
    Filed: January 21, 1994
    Date of Patent: August 22, 1995
    Assignee: Ushiodenki Kabushiki Kaisha
    Inventors: Hiromitsu Matsuno, Tatsushi Igarashi, Tatsumi Hiramoto, Yasuo Oonishi
  • Patent number: 4543472
    Abstract: Disclosed herein is a plane light source unit comprising a plurality of lamps disposed closely with each other in proximity to a mirror with the longitudinal axes of the lamps extending parallelly in a plane. Each of the lamps comprises an elongated sealed tubular body and a filament formed of alternating non-luminous portions and luminous portions and provided within the tubular body along the longitudinal axis of the tubular body. A radiant heating furnace comprising the above plane light source unit and a cooling system therefor is also disclosed. The plane light source unit and a radiant heating furnace incorporating the same light source unit can irradiate light onto a region of a large area with a uniform irradiation energy density. They are suitable for heat treatment of semiconductor wafers.
    Type: Grant
    Filed: November 3, 1982
    Date of Patent: September 24, 1985
    Assignee: Ushio Denki Kabushiki Kaisha
    Inventors: Tetsuji Arai, Tatsushi Igarashi
  • Patent number: 4540911
    Abstract: Disclosed herein is a halogen lamp unit comprising a tubular halogen lamp having at its both ends sealed portions hermetically enclosing their respective conductive members. The halogen lamp is supported by holders at its tubular outer wall portions of the envelope adjacent to the sealed end portions without base shells which cover the sealed portions. The holders are cooled by a water-cooling system. The sealed end portions of the lamp are kept in a bare state, thereby avoiding the degradation of the conductive members due to the oxidation thereof. The sealed end portions may be exposed in air-paths to the cooling wind flowing along the tubular halogen lamp.
    Type: Grant
    Filed: November 3, 1982
    Date of Patent: September 10, 1985
    Assignee: Ushio Denki Kabushiki Kaisha
    Inventors: Tetsuji Arai, Tatsushi Igarashi