With Means For Controlling Gas Flow Patents (Class 372/58)
  • Patent number: 5848089
    Abstract: An electric discharge gas laser having a laser cavity in which is contained a laser gas and a fan for circulating the laser gas. The fan is supported by an active magnetic bearing system and driven by a brushless DC motor in which the rotor of the motor and at least two magnetic bearings sealed within the gas environment of the laser cavity and the motor stator and the coils of the bearing magnets are located outside the gas environment.
    Type: Grant
    Filed: July 11, 1997
    Date of Patent: December 8, 1998
    Assignee: Cymer, Inc.
    Inventors: Kamal Sarkar, Richard C. Ujazdowski, Palash P. Das, Donald G. Larson
  • Patent number: 5799031
    Abstract: The gas mixture leaving the laser apparatus (1) is recycled to a permeator (45) which separates it into two flows. The discharge from the permeator is expanded in an expansion turbine (27) coupled to a compressor (35) for exerting suction on the recycled mixture, which makes it possible to obtain the desired reduced pressure in the laser apparatus. Applications to power laser apparatuses with nitrogen/carbon dioxide mixture, intended for cutting materials.
    Type: Grant
    Filed: January 26, 1996
    Date of Patent: August 25, 1998
    Assignee: L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude
    Inventors: Bruno Marie, Daniel Guerin, Christian Larquet, Antoine Willemot
  • Patent number: 5771258
    Abstract: An excimer laser chamber capable of arc-free operation at repetitive pulse rates of 1 kHz or greater is provided. The chamber balances the electrode design criteria required to produce a well-defined discharge channel with the flow design criteria required to achieve high clearing rates at comparatively high blower efficiency. A ceramic insulator located on either side of the cathode/pre-ionizer assembly enhances the flow of gas through the discharge region by reducing the turbulence in the electrode region. A series of specifically designed flow vanes further enhance the gas flow. The gas exiting the blower fan is guided into the discharge region with one vane. The anode support bar is extended downwardly, thus improving the efficiency of the tangential blower and also minimizing the amount of gas bypassing the discharge region. A pair of vanes downstream from the discharge region smoothly direct the heated gas towards the heat exchanger.
    Type: Grant
    Filed: May 16, 1997
    Date of Patent: June 23, 1998
    Assignee: Cymer, Inc.
    Inventors: Richard George Morton, Igor Vladimirovich Fomenkov, William Norman Partlo
  • Patent number: 5770933
    Abstract: A brushless DC motor with an adjustable timing feature is provided. The timing adjustment allows a specific motor's performance to be optimized by compensating for individual variations both in the characteristics of the rotor position sensors as well as in their locations. The rotor position sensors may be affixed to a heat sink within a portion of the motor housing. To improve the cooling efficiency of the heat sink at least a portion of the motor housing to which the heat sink is thermally coupled is cooled through either active or passive cooling. The rotor position sensors may be enclosed by a structure which improves their thermal and electrical isolation. A means of monitoring and controlling the speed of the motor is also provided.
    Type: Grant
    Filed: November 13, 1997
    Date of Patent: June 23, 1998
    Assignee: Cymer, Inc.
    Inventors: Donald Glenn Larson, Tom Arthur Watson
  • Patent number: 5754581
    Abstract: A method and apparatus for generating uniform, transverse-electrical discharges in gaseous media between two principal discharge electrodes is described. At least one of the electrodes is segmented and a differential voltage is generated between the segments. Voltage from a single high-voltage source is applied between the principal discharge electrodes and between the segments of the segmented electrode through a single switch. A differential voltage suitable for producing a discharge between the segments is generated therebetween from the high-voltage source by using a differential impedance circuit. Once sufficient ionization is generated, a discharge between the principal electrodes occurs. The invention has been demonstrated to be useful for providing electrical excitation for a carbon dioxide laser oscillator which may be operated in either a flowing gas or sealed mode.
    Type: Grant
    Filed: November 18, 1996
    Date of Patent: May 19, 1998
    Inventor: Edward J. McLellan
  • Patent number: 5754579
    Abstract: A first object is to stabilize output of laser light. In order to achieve the first object, if it is detected by an output detection means (15) that the output (E) of laser light (La) has departed from a target value, whilst maintaining the voltage of a power source (17) at a fixed value or in a fixed range, the amount of laser gas supplied to a laser chamber (4) is controlled such that the output (E) of laser light becomes the target value. A second object is to reduce the wear of the pre-ionization electrodes and to prevent drop in output of laser light. The second object is achieved as follows. Specifically, the pulse current discharged from primary capacitor (C1) is stepped up in voltage by a pulse transformer and is charged onto a secondary capacitor (C2).
    Type: Grant
    Filed: December 13, 1996
    Date of Patent: May 19, 1998
    Assignee: Komatsu Ltd.
    Inventors: Hakaru Mizoguchi, Toshihiro Nishisaka, Hiroshi Komori
  • Patent number: 5748662
    Abstract: A laser oscillator has a casing 10. A cooling medium is supplied from an inlet port 134 to a heat exchanger 8 via a pipe 35, and discharged form it via a pipe 37 and an outlet port 136. The ports 134 and 136 are symmetrically positioned relative to a center line of the casing when seen from upward. An inlet port 340 and an outlet port 342 have a similar positional relation ship thereto.
    Type: Grant
    Filed: March 27, 1997
    Date of Patent: May 5, 1998
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Satoshi Nishida, Akihiro Otani
  • Patent number: 5745513
    Abstract: A laser oscillator has a casing 10. A cooling medium is supplied from an inlet port 134 to a heat exchanger 8 via a pipe 35, and discharged form it via a pipe 37 and an outlet port 136. The ports 134 and 136 are symmetrically positioned relative to a center line of the casing when seen from upward. An inlet port 340 and an outlet port 342 have a similar positional relation ship thereto.
    Type: Grant
    Filed: March 27, 1997
    Date of Patent: April 28, 1998
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Satoshi Nishida, Akihiro Otani
  • Patent number: 5742627
    Abstract: A laser oscillator system has prolonged service lives of optical components thereof by preventing dust and the like from being produced from heat exchanger, the heat exchanger being reduced in size, and further, generates a higher laser beam output. The laser oscillator system uses a plate type heat exchanger as a cooling unit. The plate type heat exchanger can be made free of dust and the like, during a process of manufacturing it. Hence, it is possible to prevent inclusion of dust and the like from the heat exchanger into a laser oscillator and, thereby, markedly prolong the service lives of optical component parts. Further, the plate type heat exchanger is reduced in size and weight, which makes it possible to simplify a laser gas-circulating system. Further, influence of presence thereof, such as vibrations transmitted therefrom and the like, adversely affecting an electric discharge tube and the like, is reduced.
    Type: Grant
    Filed: May 17, 1993
    Date of Patent: April 21, 1998
    Assignee: Fanuc, Ltd.
    Inventors: Yasuyuki Morita, Kenji Mitsui, Mitsuo Manabe
  • Patent number: 5735469
    Abstract: A compact diffuser for recovering pressure from a supersonic flow with boundary layers. Sharp splicer plates near the wails form boundary layer scoops and separate the flow into an inner coreflow chapel and outer chambers containing small supersonic ejector nobles. The coreflow without boundary layers undergoes a single near-normal shock to recover pressure. The boundary layers are pumped to the recovery pressure in the outer ejector chambers. The subsonic part of the boundary layer flow to the outer chambers can be choked against boundary layer scoop inlet corners to isolate the upstream flow. The leading edge angle of the splicers may be selected to help induce coreflow shocking.
    Type: Grant
    Filed: May 28, 1996
    Date of Patent: April 7, 1998
    Assignee: Boeing North American, Inc.
    Inventors: Sergio E. Rodriguez, James P. Maddox, Raymond J. Netzer, Alan Z. Ullman
  • Patent number: 5729564
    Abstract: An electrostatic precipitator is provided within the housing of a gas discharge laser, such as an exciter laser, to collect and trap dust particles generated in the course of laser operation. The precipitator comprises a plurality of spaced collector plates mounted within the laser housing for flow-through passage of a lasing gas circulated by a fan through a laser discharge zone disposed between a pair of main electrodes. The collector plates are appropriately charged to define one precipitator pole, the opposite pole being defined by the laser discharge zone and the ionization and fluorescent discharge associated therewith during laser operation. The collector plates are shaped and spaced for changing the lasing gas flow direction and for reducing the flow velocity as the lasing gas circulates between the plates, to achieve enhanced electrostatic collection of dust.
    Type: Grant
    Filed: July 31, 1996
    Date of Patent: March 17, 1998
    Assignee: VISX, Incorporated
    Inventor: David I. Cullumber
  • Patent number: 5727011
    Abstract: A laser apparatus includes an output mirror and a total reflection mirror. A discharge tube is located between the output mirror and the total reflection mirror. The discharge tube contains laser medium gas. A first block connected to a first end of the discharge tube supports the first end of the discharge tube and also the output mirror. A second block connected to a second end of the discharge tube supports the second end of the discharge tube and also the total reflection mirror. A third block connected to an intermediate portion of the discharge tube supports the intermediate portion of the discharge tube. An optical bench supports the first block, the second block, and the third block. A turboblower connected to the third block is supported by the third block. A first passage connects the turboblower and the first block. A second passage connects the turboblower and the second block.
    Type: Grant
    Filed: June 12, 1996
    Date of Patent: March 10, 1998
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Doukei Choo, Shigeki Yamane
  • Patent number: 5701320
    Abstract: The compensation amount of the pressure for keeping the index of refraction of the gas constant is calculated on the basis of the pressures and the temperatures that have been measured at different time. Only the pressure of the gas will be varied in accordance with the calculated compensation value of the pressure, whereby the index of the gas can be maintained constant and the oscillation frequency can be kept constant as the consequence. The pressure corresponding to a desired sweeping oscillation frequency is also calculated using the measured pressures and temperatures. The pressure of the gas is varied on the basis of the result of calculation. Synchronously with the variation of the pressure of the gas, the cavity length and the angle of the frequency selecting element are compensated.
    Type: Grant
    Filed: April 26, 1996
    Date of Patent: December 23, 1997
    Assignee: Japan Atomic Energy Research Institute
    Inventors: Akira Sugiyama, Tsuyoshi Nakayama, Masaaki Kato, Yoichiro Maruyama, Takashi Arisawa
  • Patent number: 5663977
    Abstract: A gas laser apparatus is operated in such a manner that gas supplied to a laser chamber is excited for laser oscillation. A cabinet (11) which houses gas containers (12 and 13) is located adjacent to the laser oscillator (1) or integrated with it, The piping for the laser gas is incorporated in the cabinet, Such a structure realizes an economical laser of stabilized performance and easy maintenance.
    Type: Grant
    Filed: March 19, 1996
    Date of Patent: September 2, 1997
    Assignee: Komatsu Ltd.
    Inventors: Junichi Fujimoto, Hakaru Mizoguchi
  • Patent number: 5642374
    Abstract: Aimed at preventing a laser light beam profile from fluctuating, and by using the fact that there is a substantially proportional relation between the beam profile and the charging voltage as well as between the beam profile and the composition or the total pressure of the laser gases, an excimer laser device comprises a laser chamber containing laser gases which are excited by initiating an electric discharge in the laser chamber to output laser light, a beam profile detector for detecting a beam profile of the output laser light, and a controller for controlling a electric discharge voltage (excitation intensity) and composition or total pressure of the prescribed types of laser gases in such a way that the beam profile is shaped as desired based on detection results of the beam profile detector.
    Type: Grant
    Filed: April 10, 1995
    Date of Patent: June 24, 1997
    Assignee: Kabushiki Kaisha Komatsu Seisakusho
    Inventors: Osamu Wakabayashi, Hakaru Mizoguchi
  • Patent number: 5590146
    Abstract: In a gas laser (1) with a laser gas circulation path (5) in which a fan (4) conveys the laser gas (6) through a laser discharge space or tube (2) and a cooling system (3a, 3b), the gas throughput is increased by a bypass (8) of the laser discharge space (2). In the bypass may be a filter, cooler and catalyst for treating that portion of the laser gas flowing therethrough. The volume of gas diverted through the bypass may be adjusted to improve the efficiency of the laser.
    Type: Grant
    Filed: May 19, 1995
    Date of Patent: December 31, 1996
    Assignee: Trumpf Lasertechnik GmbH
    Inventor: Michael von Borstel
  • Patent number: 5530937
    Abstract: A current detector (130) is connected between the negative output terminal (-) of a high voltage DC power source (9) and the ground; the current detector (130) comprises a core (12) which is electrostatically shielded by a grounded conductive cover (15), a coil (11) wound around the core (12) and connected in series between the negative output terminal (-) and an electrode (4b) of a gas laser (1), and a Hall device (13) which is magnetically coupled to the core (12) and sends its output signal to a control signal input terminal (91) of the high voltage DC power source (9) so as to control high voltage output power of the latter.
    Type: Grant
    Filed: April 25, 1995
    Date of Patent: June 25, 1996
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Tsutomu Sugiyama
  • Patent number: 5461636
    Abstract: There is provided a turbo blower for lasers which is capable of effectively cooling a shaft and bearings thereof. Oil held in a shaft support member is drawn up via an oil inlet port by a centrifugal force generated by rotation of the shaft, and passes through a cooling oil passage extending through the shaft to be discharged from an oil outlet port provided below an upper one of rolling bearings as the bearings. The oil discharged from the outlet port returns via an oil return passage to an oil sump. While passing through the oil return passage, the oil is cooled by a coolant circulating through an coolant passage. Further, part of the oil discharged from the oil outlet port is supplied to the upper one of the bearings for lubrication. On the other hand, part of the oil held within the shaft support member is drawn up along a tapered portion of an oil suction head by the centrifugal force generated by rotation of the oil suction head for lubrication of a corresponding one of the rolling bearings.
    Type: Grant
    Filed: December 30, 1994
    Date of Patent: October 24, 1995
    Assignee: Fanuc Ltd.
    Inventors: Norio Karube, Yasuyuki Morita, Kenji Nakahara, Kenji Mitsui
  • Patent number: 5450435
    Abstract: In a high velocity gas laser oscillator of radio frequency or microwave exciting type, both end parts of the discharge tube are provided with gas flow rectifiers for making an inward flowing whirlwind at the discharge region of the discharge tube by blowing the discharge gas through plural slits located in a plane disposed at a predetermined angle with respect to a plane including axis of the discharge tube, wherein microwave power is applied to the discharge tube so as to define an annular discharge region in the discharge tube.
    Type: Grant
    Filed: September 3, 1993
    Date of Patent: September 12, 1995
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Shigeki Yamane, Tsutomu Sugiyama, Masashi Ohnishi, Yoshimitsu Matsumoto
  • Patent number: 5450436
    Abstract: A laser system which realizes its stable operation. In the system, a spectrum width of laser light dischargingly excited in a laser chamber is detected by a spectrum width monitor. A controller controls, on the basis of the detected spectrum width, a replenishment amount of gas to be replenished from an F2 gas cylinder into the laser chamber through a sub-tank and on-off valves to cause the spectrum width to become constant.Further, when replenishment of a halogen gas diluted with a buffer gas is carried out, a gas exhaustion step of keeping the internal total gas pressure of the laser chamber constant is omitted.In addition, a laser oscillation pulse number is counted for a predetermined period of time and a replenishment amount of the halogen gas is carried out according to the count value.
    Type: Grant
    Filed: November 19, 1993
    Date of Patent: September 12, 1995
    Assignee: Kabushiki Kaisha Komatsu Seisakusho
    Inventors: Hakaru Mizoguchi, Junichi Fujimoto, Masahiko Kowaka, Tomokazu Takahashi
  • Patent number: 5440578
    Abstract: An excimer gas laser using a fluorine/krypton/neon gas mixture is provided with separate fluorine/krypton/neon and krypton/neon gas sources for use in replenishing the gas mixture. A bleed-down mechanism is also provided for draining a portion of the gas mixture from the excimer laser. A control mechanism controls operation of the separate fluorine/krypton/neon and krypton/neon sources and the bleed-down mechanism to selectively vary the gas mixture within the excimer laser to maintain an overall optimal laser efficiency. Preferably, the control system monitors operational parameters of the excimer laser including gain, wavelength, bandwidth and pulse rate, to determine whether the gas mixture within the excimer laser may have changed from an optimal mixture. The control system controls operation of the separate fluorine/krypton/neon and krypton/neon sources to compensate for changes in the operation parameters of the laser to thereby maintain high overall laser efficiency.
    Type: Grant
    Filed: July 16, 1993
    Date of Patent: August 8, 1995
    Assignee: Cymer Laser Technologies
    Inventor: Richard L. Sandstrom
  • Patent number: 5426659
    Abstract: An axial flow type laser oscillator has a laser resonator having a first gas discharge tube (5a) and a second gas discharge tube (5b) connected coaxially, serially and linearly connected (5a, 5b) to form an integral gas discharge tube (5a+5b) and a resonator base (9) containing a gas distribution paths therein for distributing the laser medium gas to both ends of the integral gas discharge tube (5a, 5b) and disposed in substantial parallelism along the laser resonator and holds both ends of said integral gas discharge tube; the resonator base is held at one end by a pin-bearing and the other end by a roller bearing, so that no stress is given to the integral gas discharge tube (5a+5b) even at temperature rise of the laser medium gas.
    Type: Grant
    Filed: December 15, 1993
    Date of Patent: June 20, 1995
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tsutomu Sugiyama, Doukei Cho
  • Patent number: 5426661
    Abstract: Low power discharge preionizers, or species, are provided by a ionizable species generator that preconditions a laser gas to eliminate arcing in lasers, such as pulsed (high repetition rate) lasers. The present invention creates the species in a low power discharge and the species prevents initial arcs from occurring between high voltage electrodes of the laser. The laser comprises a pressure vessel containing the laser gas, a fan for circulating the laser gas, a heat exchanger, a catalyst, and two high voltage discharge electrodes for exciting the laser gas to create lasing. A high voltage power source is coupled to the electrodes for providing a discharge voltage thereto. A primary auxiliary discharge source is disposed adjacent to the electrodes that is used as a preionizer that creates a low density of charged particles in the main discharge volume to act as a uniform seed for the main voltage pulse derived from the electrodes.
    Type: Grant
    Filed: September 16, 1994
    Date of Patent: June 20, 1995
    Assignee: Hughes Aircraft Company
    Inventors: David B. Cohn, Hans C. Marciniak
  • Patent number: 5416791
    Abstract: A laser oscillator that has a resonator cavity defined by oppositely disposed discharge electrodes as well as a plurality of total reflecting mirrors and a partial reflecting mirror, the resonator cavity volume containing the path of a laser beam generated by the oscillator. A laser gas medium is used to control the temperature of the oscillator and is directed in a main flow generally transverse to the path of the laser. A side flow is taken from the main flow and is directed by a duct to a position in the vicinity of the partial reflecting mirror. In order to avoid excess heating of the gas medium in the vicinity of the partial reflecting mirror and to avoid directly impacting the mirror with the gas medium, a U-shaped structure is disposed at the exit of the side flow duct, proximate to the mirror, for directing the side flow in the vicinity of but away from the mirror.
    Type: Grant
    Filed: October 28, 1993
    Date of Patent: May 16, 1995
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Akihiro Otani, Satoshi Nishida, Tatsumi Asai
  • Patent number: 5384802
    Abstract: A laser device utilizes a turbojet engine to provide a stimulation source. The turbojet engine is conventional, having a compression section, a fuel injection and igniting section, and an afterburner section. A pair of mirrors are mounted adjacent the hot gaseous stream produced by the turbojet engine. One of the mirrors is fully reflective and the other is partially reflective. The mirrors face each other and are perpendicular to the flow of the gaseous stream, creating a reflection path that is transverse to the flow. The high temperature creates excited molecules in the gaseous stream. This results in photons being emitted, which when striking other excited atoms which emit photons of the same wavelength, create additional photons to combine into a laser beam travelling along a reflection path between the mirrors. A portion of the laser beam passes through the partially reflecting mirror where it strikes an inclined mirror that aims the beam toward a desired target.
    Type: Grant
    Filed: October 20, 1992
    Date of Patent: January 24, 1995
    Assignee: Lockheed Corporation
    Inventor: Boyd B. Bushman
  • Patent number: 5383217
    Abstract: An exposure apparatus, such as a stepper, uses a laser light source requiring new gas introduction from time to time. The timing of new gas addition and partial gas replacement is controlled so that the exposure apparatus is not adversely affected. In one embodiment, the timing is such that gas introduction or replacement occurs during interruption of exposure operation, which does not start again until the fluctuation of the output of laser light caused by gas introduction or replacement is stabilized.
    Type: Grant
    Filed: March 14, 1994
    Date of Patent: January 17, 1995
    Assignee: Nikon Corporation
    Inventor: Tsunesaburo Uemura
  • Patent number: 5377216
    Abstract: A turbine-type compressor useful in a gas laser apparatus for flowing gas along a flow path of the laser includes a sealing arrangement about a drive shaft of the compressor for preventing undesirable substances from moving to the compressor impeller along the drive shaft of the compressor and contaminating the laser gas compressed thereby. The sealing arrangement includes a first seal, preferably a vacuum pressure seal, for sealing about the shaft at least during rotation of the shaft, and a second seal comprising a resilient bladder which is selectively expanded and contracted to move into and out of sealing contact with the drive shaft, respectively, for, on one hand, sealing against the shaft when the drive shaft is stationary during pumping down of the laser and, on the other hand, withdrawing the bladder from the shaft when the shaft is rotating. The sealing arrangement is reliable and relatively low cost and uses less gas than a prior art sealing arrangement.
    Type: Grant
    Filed: June 4, 1993
    Date of Patent: December 27, 1994
    Assignee: PRC Corporation
    Inventors: Carl J. Nilsen, Walter Q. Wilson, Kenneth M. Tullio
  • Patent number: 5377215
    Abstract: A housing in a laser system encloses a cathode and a displaced anode and gases ionizable and reactive chemically when a voltage pulse produces a cathode-anode electrical discharge. Moving air cools the components (capacitors, thyratron and triggering circuitry) for producing the voltage pulses. The laser gas temperature is continuously regulated at a particular value whether or not there is an electrical discharge. The concentration of one of the gases in the chamber is regulated to values alternately on opposite sides of an optimal value to provide an optimal energy in each chemical reaction of the gases. The gases are recirculated as by a fan driven on a shaft by a pair of motors and are filtered during such recirculation. The shaft speed is regulated at a particular value and the motor currents are regulated to be equal. Any ozone formed in a compartment holding the high voltage terminals is purged by passing a neutral gas (nitrogen) through the compartment to the atmosphere.
    Type: Grant
    Filed: November 13, 1992
    Date of Patent: December 27, 1994
    Assignee: Cymer Laser Technologies
    Inventors: Palash P. Das, Donald G. Larson
  • Patent number: 5373524
    Abstract: Mixing power laser apparatus, comprising a generator of a flow of excited nitrogen (1), and structure (6; 19) to introduce a flow of CO.sub.2 into the flow of excited nitrogen. The generator (1) is of the cold corona electric discharge type operating at a pressure greater than 0.3.times.10.sup.5 Pa, and is coupled to a waveguide (2) with mirrors (3, 4) opposed along a principal direction of the waveguide. For use particularly in cutting material.
    Type: Grant
    Filed: May 11, 1993
    Date of Patent: December 13, 1994
    Assignee: L'Air Liquide, Societe Anonyme Pour l'Etude et l'Exploitation des Procedes Georges Claude
    Inventors: Bruno Marie, Daniel Guerin, Christian Larquet
  • Patent number: 5373528
    Abstract: According to the present invention there is provided a laser apparatus capable of efficient oscillation with an excitation power source with comparatively low frequency, wherein discharge is obliquely generated within the rectangular section of a discharge space. There is also provided a laser apparatus with a pair of preliminary discharge excitation electrodes which can readily initiate discharge. There is further provided a laser apparatus capable of efficient oscillation with an excitation power source with comparatively low frequency, wherein provided is a pair of discharge excitation electrodes located in the major side direction of discharge space whose length is more than three times as long as that of minor side direction thereof. There is further provided a laser apparatus with a pair of discharge excitation electrodes whose dimension is smaller than that of a pair of dielectric plates, which apparatus can prevent undesirable discharge.
    Type: Grant
    Filed: January 21, 1993
    Date of Patent: December 13, 1994
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masaki Kuzumoto, Yushi Takenaka, Junichi Nishimae, Kenji Yoshizawa, Takashi Yamamoto
  • Patent number: 5369660
    Abstract: A repetitively pulsed, high energy, closed cycle photolytic atomic iodine lasers operates at 1.315 microns. Using an iodine (I.sub.2) removal system for the photolyzed C.sub.3 F.sub.7 I laser fuel, more than 70 joules/pulse is output in the fundamental mode from a M=3 confocal unstable resonator at a 0.5 Hz repetition rate. The closed cycle iodine (I.sub.2) removal system consisted of a condensative-evaporative section, two Cu mesh I.sub.2 sections, and an internal turbo-molecular blower. This closed cycle system uses C.sub.3 F.sub.7 I gas at 10-60 torr absent of I.sub.2. The turbo-molecular blower is able to push high molecular weight gases at high velocities. The turbo-molecular blower is able to produce longitudinal flow velocities greater than 10 m/s through the 150 cm long by 7.5.times.7.5 cm.sup.2 cross sectional photolytic iodine gain region. In addition to the high energy output, the resulting 7-12 .mu.sec laser beam has a beam quality less than 1.
    Type: Grant
    Filed: September 23, 1992
    Date of Patent: November 29, 1994
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: LaVerne A. Schlie, Robert D. Rathge
  • Patent number: 5359620
    Abstract: A first gas in a laser cavity is ionized by an electrical discharge in the cavity as a step in producing an energy radiation. Debris (particulates) is produced during the formation of the energy radiation. The radiation and the debris move toward an optical element in the cavity. The optical element may be a window or a mirror. The debris tends to deposit everywhere in the cavity, including on the optical element, thereby dirtying the optical element. This inhibits the efficiency in the laser operation. A clean gas is directed into the cavity through a passage at a position displaced from the optical element. The clean gas then passes in the cavity through an orifice further from the optical element than the passage. The flow of the first gas through the orifice creates a venturi effect on the clean gas to insure that the clean gas will move away from the optical element. In this way, the clean gas inhibits the first gas and the debris from moving to the optical element.
    Type: Grant
    Filed: November 12, 1992
    Date of Patent: October 25, 1994
    Assignee: Cymer Laser Technologies
    Inventor: Robert P. Akins
  • Patent number: 5331660
    Abstract: A ring laser gyro, having: an envelope for an optically resonant cavity having a gain bore section, the envelope containing an active gas medium. The envelope contains electrically gain bore energizable electrode means having at least two electrodes at electrode locations within the envelope for establishing an electrical discharge in an active gas medium between the electrode locations. The electrical discharge excites a pair of light beams along a lasing path between the electrode locations. The light beams counter-propagate in the optically resonant cavity. The envelope is coupled to means for generating an output signal for the gyro by measuring a difference in the frequencies of the light beams. The active gas medium has an axial current driven gas flow and a return gas flow induced by the electrical discharge in the gain bore. The resultant gas flow contributes to bias errors in the output signal.
    Type: Grant
    Filed: July 24, 1984
    Date of Patent: July 19, 1994
    Assignee: Rockwell International Corporation
    Inventor: James P. Hauck
  • Patent number: 5319663
    Abstract: Dust in a gas laser, particularly an excimer laser, is removed from the gas charge by one or more electrostatic precipitators that are located inside the laser vessel in the path of gas circulation that is produced by a fan and passes through the discharge area defined by the main discharge electrodes. The gas is caused to travel rapidly past the precipitator so that only a minor proportion of the dust is removed at each pass, but a low background level of dust in the gas is soon achieved and maintained by repeated such passes. This technique of employing multiple passes, each removing only a small percentage of the dust in the gas at any given time, can also be applied to a system in which the precipitator is located outside the vessel and is connected thereto by conduits.
    Type: Grant
    Filed: December 18, 1992
    Date of Patent: June 7, 1994
    Assignee: Lumonics Inc.
    Inventors: John Reid, Steven D. Hastie, George S. P. Castle
  • Patent number: 5315610
    Abstract: A modularized system for controlling the gas pressure within a copper vapor or like laser is described herein. This system includes a gas input assembly which serves to direct gas into the laser in a controlled manner in response to the pressure therein for maintaining the laser pressure at a particular value, for example 40 torr. The system also includes a gas output assembly including a vacuum pump and a capillary tube arrangement which operates within both a viscous flow region and a molecular flow region for drawing gas out of the laser in a controlled manner.
    Type: Grant
    Filed: September 22, 1986
    Date of Patent: May 24, 1994
    Assignee: The United States of America as represented the the Unites States Department of Energy
    Inventors: Terry Alger, Dennis M. Uhlich, William J. Benett, Earl R. Ault
  • Patent number: 5303253
    Abstract: A compact flowing gas laser, particularly a CO.sub.2 gas laser, wherein the path or paths between the outlet or outlets and the inlet or inlets of one or more optical resonators contain a turbine whose impeller or impellers are driven by heated gas and which drives the impeller or impellers of a rotor forming part of a compressor serving to compress the thus cooled and expanded gaseous lasing medium prior to reentry into the resonator or resonators. A first heat exchanger is installed between the turbine and the compressor, and a second heat exchanger is provided downstream of the compressor.
    Type: Grant
    Filed: June 5, 1992
    Date of Patent: April 12, 1994
    Assignee: Gebr. Becker GmbH & Co.
    Inventors: Hans-Heinrich Henning, Bernd Ellinghaus, Frank Diedrichsen, Walter Winkelstroter, Dieter Frohn
  • Patent number: 5301203
    Abstract: The scalable and stable, cw photolytically excited atomic iodine laser operates at 1.315 nm. An initial power level of 55 watts/liter was obtained via the cw photolysis of an alkyl-iodide gas like C.sub.3 F.sub.7 I. The greatly enhanced laser performance was achieved using a microwave excited, electrodeless Hg plasma lamp excited with a d.c., low ripple cw microwave radiation. Both high flow, air cooling and liquid dimethyl polysiloxane cooling of these high pressure Hg lamps provided long lifetime operation with the latter promoting, stable laser operation. Transverse flow of the above gas for the removal of the quenching by-product I.sub.2 is incorporated into the laser. To insure good laser amplitude stability, both the high power magnetrons and the lamps are liquid cooled. The scalable, prolonged and stable operation of this laser system is possible via use of a closer cycle, condensative/evaporative fuel system coupled to a high flow, internal blower for heavy gases.
    Type: Grant
    Filed: September 23, 1992
    Date of Patent: April 5, 1994
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: LaVerne A. Schlie, Robert D. Rathge
  • Patent number: 5295149
    Abstract: A gas laser device, including an a.c. power source for generating a.c. output voltage and a pair of electrodes positioned sandwiching discharge gap through which laser gas circulates. The pair of electrodes are connected to the a.c. power source for applying the a.c. voltage across the electrodes to achieve discharge in the discharge gap such as to create a positive column region and boundary layer regions, thereby to generate laser light. The positive column region is created in the discharge gap and a.c. power injected therein contributes to laser excitation. The boundary layer regions is created in a vicinity of one of the pair of electrodes, respectively and a.c. power injected therein does not contribute to laser excitation. A frequency of the a.c. power source is set to at least 700 kHz and an a.c. output voltage of the a.c. power source is set at a level such that a voltage in the positive column region is larger than a burden voltage in the boundary layer regions.
    Type: Grant
    Filed: March 19, 1993
    Date of Patent: March 15, 1994
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kiyohisa Terai, Tohru Tamagawa, Takaaki Murata, Shinji Kobayashi, Akira Moriguchi, Hirokatsu Suzuki
  • Patent number: 5291509
    Abstract: A gas laser apparatus in which a gas medium in a case and a lubricant for bearings supporting a blower for circulating the gas medium are isolated from each other, so that the lubricant can be prevented from mixing into the gas medium while no substantially large resistance is applied to the blower drive. To isolate the gas medium and the lubricant, magnetic fluid shaft seals (10, 11) are used for sealing between the lubricant for the bearings (6) for supporting rotation shafts (3a, 3b) of the blower (3) and the gas medium in the case (1).
    Type: Grant
    Filed: July 9, 1992
    Date of Patent: March 1, 1994
    Assignee: Kabushiki Kaisha Komatsu Seisakusho
    Inventors: Hakaru Mizoguchi, Junichi Fujimoto, Yoshiho Amada
  • Patent number: 5285457
    Abstract: The present invention relates to an apparatus for detecting an abnormal bearing condition of a blower utilized for gas laser equipment, and the purpose of the invention is to immediately find abnormal bearing conditions of the blower as a result of lubrication failures.
    Type: Grant
    Filed: December 18, 1992
    Date of Patent: February 8, 1994
    Assignee: Fanuc Ltd.
    Inventors: Tsutomu Funakubo, Kenji Nakahara
  • Patent number: 5268919
    Abstract: A gas laser oscillating unit comprises: an electric discharge tube 1 for generating an electric discharge which is to be used as a laser excitation source for laser gas flowing in one direction 17 between an anode 3 and a cathode 2 which are made of a metal material and located at both ends of the electric discharge tube 1, a tube member 22 having a pair of slits 21 for generating a swirl of laser gas upstream of the cathode 2, and a tapered hollow member 23 having a tapered inner surface 23a for squeezing the laser gas stream. The cathode 2 is connected with the tube member 22 through the tapered hollow member 23. At least the inner surface of each of the tube member 22 and the tapered hollow member 23 is made of an alloy material containing aluminum and is processed to form a black alumite layer 31 thereon, wherein the black alumite layer 31 is made from an inorganic material.
    Type: Grant
    Filed: March 4, 1992
    Date of Patent: December 7, 1993
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hitoshi Hongu, Yutaka Iwasaki
  • Patent number: 5247534
    Abstract: A pulsed gas-discharge laser, in particular an excimer laser, comprises main discharge electrodes (10, 10a) of erosion-resistant metal between which laser gas flows with high velocity to replace the laser gas between the main discharge electrodes from laser pulse to laser pulse. For preionizing the laser gas two X-ray radiation sources (30, 30a) are arranged adjacent one main discharge electrode (10). The flow path (18) of the laser gas is formed partially by flow bodies (16, 16a, 32, 32a) which consist of a material which has a high secondary emissive power with regard to the X-ray radiation. The secondary radiation is so configured that it promotes the preionization.
    Type: Grant
    Filed: March 27, 1992
    Date of Patent: September 21, 1993
    Assignee: Lambda Physik Forschungsgesellschaft mbH
    Inventor: Elmar Muller-Horsche
  • Patent number: 5239552
    Abstract: A laser output unit according to the present invention comprises a body having a laser output port at an extreme and thereof, lenses provided within said body to condense laser beam introduced to emit it from the laser output port, and a protective glass provided between said laser output port and said lens within said body. A gas jet port and a gas exhaust port opposed to said gas jet port are provided at said body portion between said protective glass and said laser output port. A gas crosses at a position between the protective glass and the laser output port. Flying matter is blown away by the gas and does not arrive at the protective glass.
    Type: Grant
    Filed: March 31, 1992
    Date of Patent: August 24, 1993
    Assignees: Miyachi Technos Corporation, Mitsui Petrochemical Industries, Ltd.
    Inventors: Hiroyuki Okuyama, Minoru Kojima, Mitsugu Terada, Seigoh Murakami, Takahiro Uchida
  • Patent number: 5239553
    Abstract: A discharge-pumped gas laser has a pressure container filled with a laser gas under pressure and a pair of elongate main discharge electrodes. The main discharge electrodes are disposed in the pressure container in confronting relationship to each other for producing an electric discharge in the laser gas in a main discharge region defined therebetween to excite the laser gas for laser emission. The laser gas is circulated to flow through the main discharge region in a direction perpendicular to the main discharge electrodes. The laser gas in the main discharge region is preionized by an UV preionizer disposed either upstream or downstream of the main discharge region with respect to the direction of flow of the laser beam. The pressure container houses a baffle partition for controlling the laser gas to flow past one of the main discharge electrodes and the preionizer while blocking the laser gas from directly flowing to the other of the main discharge electrodes and the preionizer.
    Type: Grant
    Filed: April 22, 1992
    Date of Patent: August 24, 1993
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Takuhiro Ono, Naoya Horiuchi, Keiichiro Yamanaka, Kenichi Takahata, Nobuaki Furuya, Takeo Miyata
  • Patent number: 5206875
    Abstract: In order to improve a gasdynamic CO laser, comprising an excitation region, in which a laser gas is excited, a supersonic nozzle, through which the laser gas flows, a laser-active region penetrated by a resonator beam path and a closed laser gas circuit, in which the laser gas is cyclically conducted, such that this requires smaller pumping capacities and is therefore suitable for commercial uses, it is suggested that the supersonic nozzle be designed such that at a downstream outlet thereof the laser gas has a temperature in the region of approximately 80 to approximately 180 Kelvin.
    Type: Grant
    Filed: August 30, 1991
    Date of Patent: April 27, 1993
    Assignee: Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V.
    Inventors: Hartwig Von Buelow, Eberhard Zeyfang
  • Patent number: 5206873
    Abstract: A turbo blower is used in combination with a gas laser oscillation device for machining, e.g., cutting off, workpieces. The turbo blower comprises a shaft (2) having an impeller (1) on one end thereof, a pair of bearings (5, 6) on which the shaft (2) is supported, and a motor (3, 4) for rotating the shaft. Heat radiating fins (11) are mounted on the shaft (2) for radiating the heat which is generated by a rotor (3) of the motor, thus preventing the heat from being transmitted to the bearings (5, 6). The heat radiating fins are forcibly cooled by a portion of a laser gas for thereby greatly increasing the heat radiation efficiency. The service life of the grease in the bearings and the bearings themselves is increased, thus reducing an expenditure of labor for grease replenishment and bearing replacement. The bearings are also increased in reliability.
    Type: Grant
    Filed: May 22, 1991
    Date of Patent: April 27, 1993
    Assignee: Fanuc Ltd.
    Inventors: Tsutomu Funakubo, Norio Karube, Kenji Nakahara
  • Patent number: 5200971
    Abstract: In order to improve a high-frequency excited gas laser with longitudinal flow, comprising a discharge channel having laser gas flowing therethrough in a direction of flow and high-frequency electrodes arranged on both sides of the discharge channel for generating a high-frequency discharge transversely to the direction of flow, such that a high output can be achieved with this laser in a manner which is, constructionally, as simple as possible and that its design is, at the same time, as compact as possible, it is suggested that the discharge channel comprise a plurality of channel elements, the channel axes of which are aligned parallel to one another in the direction of flow, that the channel elements be arranged beside or next to one another in a direction of installation transverse to the direction of flow and that the channel elements have a cross section having a greater extension in a first cross direction at right angles to the direction of flow than in a second cross direction extending at right angl
    Type: Grant
    Filed: January 23, 1992
    Date of Patent: April 6, 1993
    Assignees: Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V., Rofin-Sinar Laser GmbH
    Inventors: Eberhard Wildermuth, Hartwig Von Buelow, Wolfram Schock, Joerg Porath, Klaus Schanz
  • Patent number: 5199041
    Abstract: A method of modulating an oxygen-iodine laser comprises applying an external magnetic field having an intensity of up to 800 A.cm.sup.-1 to the active zone of the laser and, at the same time, changing the magnetic field intensity to change the output power of the laser.
    Type: Grant
    Filed: July 12, 1991
    Date of Patent: March 30, 1993
    Assignee: Ceskoslovenka Akademie Ved
    Inventors: Josef Schmiedberger, Jarmila Kodymova, Jiri Kovar, Otomar Spalek, Pavel Trenda
  • Patent number: 5177760
    Abstract: A gas laser includes an inner tube filled with gas and having mirrors at its opposite ends to define a resonant chamber, an outer tube filled with gas and defining a gas reservoir for the gas in the resonant chamber, and electrodes for energizing the gas in the resonant chamber. The gas reservoir includes a pair of intermediate tubes coaxial with and between the inner and outer tubes. One of the intermediate tubes is open at one end facing one end of the laser and is joined at its opposite end facing the opposite end of the laser to the outer tube. The other intermediate tube is open at its end facing the opposite end of the laser and is joined at its end facing the one end of the laser to the inner tube, whereby the pair of intermediate tubes divide the reservoir into a plurality of annular spaces defining a zigzag path between the opposite ends of inner tube.
    Type: Grant
    Filed: August 30, 1991
    Date of Patent: January 5, 1993
    Assignee: Laser Industries Ltd.
    Inventor: Joseph Kuch
  • Patent number: 5175742
    Abstract: In a pulsed gas laser apparatus for operation at ambient pressure comprising a laser module having a tubular window open at its distal end for the coupling or uncoupling of a laser beam, the tubular window has a volume which is at least equal to, or a multiple of, the volume change of the laser gas in the module during pulsed laser operation and extends essentially vertically from the laser module. The window includes a mixing zone in which during pulsed laser operation both laser gas and ambient gas are present, the window extending downwardly if the laser gas is lighter than the ambient gas and upwardly if the laser gas is heavier than the ambient gas thereby to counteract infiltration of ambient gas into the window. Also, means are provided for controlling the laser gas volume supplied to the module such that the concentration of the ambient gas in the mixing zone in the window remains below a predetermined limit.
    Type: Grant
    Filed: December 4, 1991
    Date of Patent: December 29, 1992
    Assignee: Uranit GmbH
    Inventor: Udo Freyaldenhoven