High pressure arc lamp assisted start up device and method

Details High pressure arc lamp assisted start up device and method High pressure arc lamp assisted start up device and method

2001-07-23

2003-04-01

Wong, Don (Department: 2821)

Electric lamp and discharge devices: systems

Combined load device or load device temperature modifying...

Discharge device load

C313S491000, C313S631000

Reexamination Certificate

active

06541915

ABSTRACT:

FIELD OF THE INVENTION
The field of the invention is arc lamps such as metal-halide, sodium, mercury or rare gas lamps.
BACKGROUND OF THE INVENTION
High-pressure arc lamps (including metal-halide, sodium, mercury, and rare gas lamps and often referred to as high intensity discharge lamps) currently produce, on a continuous basis, several billion watts of visible light worldwide. A major factor limiting the life of these lamps is the process of starting and re-igniting the lamp. The startup or re-ignition of an arc lamp requires the production of charge carriers and, in conventional lamps, this is normally done by imposing a large voltage across the lamp. This voltage creates an electric field between the discharge electrodes that ionizes a fraction of the gas atoms or molecules in this region. The positive ions (anions) and electrons produced by ionization are drawn, under the influence of the electric field, to the cathode and anode, respectively, giving rise to a current. Near the cold cathode, the anions normally are responsible for carrying most of the current. As they approach the cathode, the anions are accelerated in a strong electric field and, upon impact with the cathode, cause the release of secondary electrons from the cathode. In the early stages of the start up of an arc lamp this is the dominant source of electron production near the cathode. Unfortunately, when an ion collides with the cathode, sputtering of the cathode also occurs. Some of the sputtered cathode material (generally a metal or alloy such as thoriated tungsten) coats the inside of the envelope of the lamp, thereby reducing the fraction of the light produced by the lamp that is able to escape. This process is called wall darkening. Each time the lamp is ignited or re-ignited, the operating life of the lamp is reduced further by this process.
SUMMARY OF THE INVENTION
The invention assists in the cold startup or re-ignition of a high-pressure arc lamp. One or more microdischarge devices produces and injects electrons and ions into the region between the cathode and anode. The microdischarge device(s) do not serve as the cathode itself but augment electron and ion production in the early stages of lamp ignition or re-ignition. Once the glow (and arc) is firmly established between the anode and cathode, the microdischarge device(s) can be extinguished and the lamp will function in a conventional manner.


REFERENCES:
patent: 4992703 (1991-02-01), Ramaiah
patent: 5686789 (1997-11-01), Schoenbach et al.
patent: 6139384 (2000-10-01), DeTemple et al.
patent: 6194833 (2001-02-01), DeTemple et al.
L. C. Pitchford, I. Pérès, K. B. Liland, J. P. Boeuf, and H. Gielen,J. Appl. Phys. 82, 112 (1997).
J. F. Waymouth,IEEE Trans. Plasma Sci. 19, 1003 (1991).
R. H. Stark and K. H. Schoenbach,J. Appl. Phys. 85, 2075 (1999).
A.D. White, “New Hollow Cathode Glow Discharge”,Journal of Applied Physics, vol. 30, No. 5, May 1959, pp. 711-719.
K.H. Schoenbach, R. Verhappen, T. Tessnow, and F.E. Peterkin, and W.W. Byszewski, “Microhollow cathode discharges”,Appl. Phys. Lett. 68(1), Jan. 1, 1996, pp. 13-15.
J.W. Frame, D.J. Wheeler, T.A. DeTemple, and J.G. Eden, “Microdischarge devices fabricated in silicon”,Appl. Phys. Lett 71(9), Sep. 1, 1997, pp. 1165-1167.
Leopold D. Biborosch, Okiver Bilwatsch, Shlomo Ish-Shalom, Eduard Dewald, Uwe Ernst, and Klaus Frank, “Microdischarges with plane cathodes”,Applied Physics Letters, vol. 75, No. 25, Dec. 20, 1999, pp. 3926-3928.
Ahmed El-Habachi, Wenhui Shi, Mohamed Hoselhy, Robert H. Stark, and Karl H. Schoenbach, “Series operation of direct current xenon chloride excimer sources”,Journal of Applied Physics, vol. 88, No. 6, Sep. 15, 2000, pp. 3220-3224.
J.W. Frame, P.C. John, T.A. DeTemple, and J.G. Eden, “Continuous-wave emission in the ultraviolet from diatomic excimers in a microdischarge,”Applied Physics Letters, vol. 72, No. 21, May 25, 1998, pp. 2634-2636.
S.J. Park, C.J. Wagner, and J.G. Eden,Fellow, IEEE“Performance of Microdischarge Devices and Arrays with Screen Electrodes”,IEEE Photonics Technology Letters, vol. 13, No. 1, Jan. 1, 2001, pp. 61-63.
S.J. Park, C.J. Wagner, C.M. Herring, and J.G. Eden, “Flexible microdischarge arrays: Metal/polymer devices”,Applied Physics Letters, vol. 77, No. 2, Jul. 10, 2000, pp. 199-201.
J.W. Frame and J.G. Eden, “Planar microdischarge arrays”,Electronics Letters, vol. 34, No. 15, Jul. 23, 1998, pp. 1-2.
S.J. Park, J. Chen, C. Liu and J.G. Eden, “Arrays of microdischarge devices having 50-100&mgr;m square pyramidal Si anodes and screen cathodes”,Electronics Letters, vol. 37, No. 3, Feb. 1, 2001, pp. 1-2.

Affiliated with

Also associated with

Rating

High pressure arc lamp assisted start up device and method does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with High pressure arc lamp assisted start up device and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High pressure arc lamp assisted start up device and method will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3053077