Starting aid for discharge lamp
View Patent ↗An arc discharge lamp ( 10 ) having an arc tube ( 12 ) containing an arc generating and sustaining medium ( 13 ) and first and second spaced apart electrodes ( 14, 16 ), respectively. An envelope ( 18 ) surrounds the arc tube ( 12 ) and contains an atmosphere ( 19 ) within it. The atmosphere is of a composition and pressure that will provide a burst of UV radiation in response to a spark generated within the envelope ( 18 ) and, in a preferred embodiment of the invention, is selected from argon or nitrogen (with nitrogen being preferred) at a pressure of from 150 to 400 torr. First and second electrical lead-ins ( 20, 22 ) are sealed within the envelope ( 18 ), with the first lead-in ( 20 ) being electrically connected to the first electrode ( 14 ) and the second lead-in ( 22 ) being connected to the second electrode ( 16 ), for example, by connector wire ( 22 a ). Means ( 30 ) is contained within the envelope ( 18 ) and exposed to the atmosphere ( 19 ) for generating a UV-producing spark within the atmosphere ( 19 ). As shown in the embodiment of FIG. 1 the means ( 30 ) comprises an isolated pin ( 24 ) mounted in the seal area ( 26 ) of the arc tube ( 12 ) adjacent the first electrode ( 14 ), a resistor ( 28 ) electrically connected between the second lead-in ( 22 ) and the isolated pin ( 24 ). A spark gap G is formed between the first electrode ( 14 ) and the isolated pin ( 24 ).
1. In an arc discharge lamp having:
an arc tube containing an arc generating and sustaining medium and first and second spaced apart electrodes:
a lamp envelope surrounding said arc tube and a lamp atmosphere within said lamp envelope;
first and second electrical lead-ins sealed within said lamp envelope, said first lead-in being electrically connected to said first electrode and said second lead-in being connected to said second electrode;
the improvement comprising:
means contained within said lamp envelope and exposed directly to said lamp atmosphere for generating a UV-producing spark within said lamp atmosphere.
2. The arc discharge lamp of claim 1 wherein said means comprises an isolated pin mounted in said arc tube adjacent said first electrode and exposed to said lamp atmosphere, a resistor electrically connected between said second lead-in and said isolated pin: and;
a spark gap G between said first electrode and said isolated pin within said lamp atmosphere.
3. The arc discharge lamp of claim 2 wherein a space S exists between said first electrode and said isolated pin and said spark gap G is less than said space S.
4. The arc discharge lamp of claim 1 wherein said means comprises a resistor having a first end electrically connected to said second lead-in and a second end formed in a spark gap relation with said first lead-in.
5. The arc discharge lamp of claim 1 wherein said atmosphere is nitrogen.
6. The arc discharge lamp of claim 5 wherein said nitrogen is present at a pressure of 150 to 400 torr.
7. An arc discharge lamp comprising:
an arc tube containing an arc generating and sustaining medium and first and second spaced apart electrodes:
a lamp envelope surrounding said arc tube and a lamp atmosphere within said envelope;
first and second electrical lead-ins sealed within said lamp envelope;
a frame member having a first end electrically and mechanically secured to said first lead-in and a second end including means engaged with and supporting said arc tube;
an isolated pin sealed in an end of said arc tube adjacent said first electrode and exposed to said lamp atmosphere;
a resistor electrically connected between said second lead-in and said isolated pin: and
an electrical connector having a proximal end fixed to said frame member, an intermediate portion fixed to said first electrode; and a distal portion terminating in a spark gap with said isolated pin.
8. The arc discharge lamp of claim 7 wherein said electrical connector is ribbon-shaped.
9. The arc discharge lamp of claim 8 wherein said ribbon is nickel.
10. The arc discharge lamp of claim 7 wherein said atmosphere is nitrogen.
11. The arc discharge lamp of claim 10 wherein said nitrogen is present at a pressure of 150 to 400 torr.