Electric lamp and discharge devices – With optical device or special ray transmissive envelope – Reflector
Reexamination Certificate
1997-12-30
2001-08-14
Patel, Nimeshkumar D. (Department: 2879)
Electric lamp and discharge devices
With optical device or special ray transmissive envelope
Reflector
C313S046000, C313S117000
Reexamination Certificate
active
06274970
ABSTRACT:
FIELD OF INVENTION
This invention relates to an arc lamp, and more particularly to such an arc lamp pulsed or continuous having an internal spherical reflector and/or a back scatter deflector.
BACKGROUND OF INVENTION
Conventional arc lamps, pulsed or continuous, provide a high energy density, high intensity, sharply defined source which is desirable in a number of applications. The high energy density and high intensity make arc lamp sources desirable in spectroscopy where the chemical sensitivity is a direct function of the energy density at the target sample. The high energy density and high intensity are also useful in miniaturization applications such as in fiber optic light transmission for endoscopic uses and generally in photographic illumination applications where a high intensity minute controlled source of illumination is essential. One shortcoming of such lamps is that more than half of the radiation generated is lost because of backscattering of the rearward directed radiation within the arc lamp. Worse still, that lost, backscattered rearward radiation increases the heating of the lamp and contributes to optical noise that interferes with the output beam. In some designs paraboloidal and ellipsoidal internal reflectors have been used to collect and control more of the available arc radiation but because of electrode orientation can cause a void or black hole in the direct radiation, and each of them inadvertently increases magnification at the target which in most applications is undesirable.
SUMMARY OF INVENTION
It is therefore an object of this invention to provide an improved arc lamp of the continuous or pulsed type.
It is a further object of this invention to provide such an improved arc lamp which can substantially increase radiation output without increase in power input.
It is a further object of this invention to provide such an improved arc lamp which can substantially reduce power while maintaining radiation output.
It is a further object of this invention to provide such an improved arc lamp which conserves energy.
It is a further object of this invention to provide such an improved arc lamp which recaptures radiation emitted rearwardly away from the window and redirects through the window with the forward transmitted radiation.
It is a further object of this invention to provide such an improved arc lamp which dramatically reduces optical noise generated by the backscattered rearward directed radiation.
It is a further object of this invention to provide such an improved arc lamp which substantially reduces the heat loss in the arc lamp.
It is a further object of this invention to provide such an improved arc lamp which generates a high energy density, high intensity radiation beam without voids or holes.
It is a further object of this invention to provide such an improved arc lamp which imposes no unwanted magnification.
The invention results from the realization that a higher energy density, high intensity radiation beam can be obtained from a continuous or pulsed arc lamp by employing either or both (1) a spherical reflector having its center at the arc and disposed on the other side of the arc from the exit window to collect radiation emanating rearwardly from the arc, whose plasma is transparent to the redirected radiation, and redirect it through the center to add to the forward radiation transmitted through the window; (2) a backscatter deflector for suppressing backscattered radiation and preventing it from interfering with the forward radiation.
This invention features an arc lamp including a housing, a pair of spaced electrodes in the housing, and an inert gas in the housing for establishing an arc in the gas to generate a radiation output. There is a window in the housing for transmitting forward radiation generated by the arc. A spherical reflector on the opposite side of the electrodes from the window has its center disposed in the arc for redirecting rearward radiation through the center to add to the forward radiation transmitted through the window.
In a preferred embodiment the housing may be made of glass or metal. The window may be made of glass. The gas may be an inert gas such as xenon, krypton or argon. There may be trigger means for initiating the arc. The trigger means may include a trigger electrode and a pulsed power source and the arc lamp is a pulsed arc lamp. The trigger means may include an ignition power source and a continuous power source for a continuous arc lamp. The trigger electrode may be inside the housing. The ignition power source may include an overvoltage source. The electrodes may be aligned transverse to the direction of transmission of radiation through the window.
This invention also features an arc lamp including a housing, an inert gas in the housing and a pair of spaced electrodes in the housing for establishing an arc in the gas to generate a radiation output. There is a window in the housing for transmitting forward radiation generated by the arc and a deflector on the opposite side of the electrodes from the windows and having a rearward deflection surface for preventing backscatter radiation from the arc from passing through the arc and out the window.
In a preferred embodiment the deflector may have a forward deflection surface for receiving and redirecting backscattered radiation from the arc so that the backscattered radiation is prevented from propagating through the arc and window. The deflector may be black and may be specular. The rearward deflection surface may be flat. The forward reflection surface may be conical. The forward reflection surface may be a spherical mirror. The spherical mirror may have its center in the arc. The housing may be glass or metal. The window may be glass. The gas may be xenon, krypton or argon. There may be trigger means for initiating the arc and the trigger means may include a trigger electrode and a pulse power source wherein the arc lamp is a pulsed arc lamp. The trigger means may include an ignition power source in the continuous power source wherein the arc lamp is a continuous arc lamp. The trigger electrode may be inside the housing. The ignition power source may include an overvoltage source and the electrodes may be aligned transverse to the direction of transmission of radiation through the window.
REFERENCES:
patent: 3527974 (1970-09-01), Cooper
patent: 3559546 (1971-02-01), McKee
patent: 3731133 (1973-05-01), McRae et al.
patent: 3766430 (1973-10-01), Schlegel
patent: 4020379 (1977-04-01), Manning
patent: 4188657 (1980-02-01), Reibling
patent: 4599540 (1986-07-01), Roberts
patent: 4633128 (1986-12-01), Roberts et al.
patent: 5128596 (1992-07-01), Shimazu et al.
patent: 5399931 (1995-03-01), Roberts
patent: 5721465 (1998-02-01), Roberts
Capobianco, R.A., “Xenon: The Full Spectrum vs. Deuterium Plus Tungsten”, EG&G Optoelectronics 6/97.
Capobianco,R.A.,“Optical Coupling of Flashlamps and Fiber Optics”, EG&G Optoelectronics 6/97.
Capobianco, R.A.,“High-Stabilityt Pulsed Light Systems”, EG&G Optoelectronics 6/97.
Advertisement 1100 Series High Stability Short Arc Xenon Flashlamps, EG&G Optoelectronics 2/94.
Advertisement, 1100 Series FlashPacs, EG&G Optoelectronics, 1/97.
Advertisement, 1100 Series Lite-Pac Trigger Modules, EG&G Optoelectronics 2/94.
Advertisement, 1100 Series FX-1160, High Output Short Arc Xenon Flashlamp With Internal Reflector, EG&G Optoelectronics 10/96.
Advertisement, LabPac PS 1200 Laboratory Flashlamp Power Supply, EG&G Optoelectronics 1/97.
Advertisement, 1100 Series Power Supplies, EG&G Optoelectronics 2/94.
Advertisement, 1100 Series Short Arc Flashlamps, Trigger Modules and Power Supplies, EG&G Optoelectronics 1/94.
Iandiorio & Teska
Patel Nimeshkumar D.
PerkinElmer Inc.
Williams Joseph
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