Excitation coil for an electrodeless high intensity discharge lamp
First Claim
1. An excitation coil for exciting an arc discharge in an electrodeless high intensity discharge lamp, comprising:
- a conductive surface configured to form at least one coil turn, said conductive surface having a shape determined by rotating a substantially bilaterally symmetrical trapezoid about a center line which does not intersect said trapezoid, said trapezoid having a relatively short parallel side and a relatively long parallel side, said short parallel side being disposed toward said center line to form the inner surface of said coil; and
means for coupling said excitation coil to a radio frequency power supply.
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Accused Products
Abstract
An excitation coil for a high intensity discharge lamp has an optimized configuration for maximizing efficiency and minimizing output light blockage. The coil includes a conductive surface having a shape which corresponds to rotating a bilaterally symmetrical trapezoid about a coil center line in the same plane as the trapezoid without intersecting the center line. The conductive surface is disposed on a conductive core for efficient heat removal from the coil, resulting in reduced coil losses. In one embodiment, the coil cross section is increased by adding a rectangular portion to the trapezoidal portion, thereby extending the coil outwardly from the coil center line so as to remove heat from the coil more quickly without affecting light output from the lamp.
163 Citations
18 Claims
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1. An excitation coil for exciting an arc discharge in an electrodeless high intensity discharge lamp, comprising:
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a conductive surface configured to form at least one coil turn, said conductive surface having a shape determined by rotating a substantially bilaterally symmetrical trapezoid about a center line which does not intersect said trapezoid, said trapezoid having a relatively short parallel side and a relatively long parallel side, said short parallel side being disposed toward said center line to form the inner surface of said coil; and means for coupling said excitation coil to a radio frequency power supply. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An electrodeless high intensity discharge lamp, comprising:
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a light-transmissive arc tube for containing a fill; an excitation coil disposed about said arc tube for exciting an arc discharge in said fill, said excitation coil comprising a conductive surface configured to form at least one coil turn, said conductive surface having a shape determined by rotating a substantially bilaterally symmetrical trapezoid about a center line which does not intersect said trapezoid, said trapezoid having a relatively short parallel side and a relatively long parallel side, said short parallel side being disposed toward said center line to form the inner surface of said coil; and means for coupling said excitation coil to a radio frequency power supply. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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Specification