Projection device and discharge lamp thereof

1. A discharge lamp disposed in a projecting device, comprising:

a housing;

a discharge vessel disposed in the housing and having an axis, wherein the discharge vessel is configured to contain a gas;

an ultraviolet (UV) source disposed at a predetermined distance from the axis and configured to excite the gas;

a first electrode having a first end disposed inside the discharge vessel along the axis; and

a second electrode having a second end disposed inside the discharge vessel along the first-axis and opposite to the first end, wherein the first and second electrodes are configured to receive a voltage to excite the gas and form a beam, and wherein the voltage is greater than 10 kV.

2. The discharge lamp of claim 1 wherein the housing is a reflector encompassing the discharge vessel, and wherein the reflector is configured to reflect the beam along an optical path.

3. The discharge lamp of claim 1 wherein the ultraviolet source is disposed inside the housing.

4. The discharge lamp of claim 3 wherein the ultraviolet source is disposed adjacent to the discharge vessel.

5. The discharge lamp of claim 3 wherein the ultraviolet source is disposed between the discharge vessel and the reflector.

6. The discharge lamp of claim 3 wherein the ultraviolet source is disposed on the reflector.

7. The discharge lamp of claim 1 wherein the ultraviolet source is disposed outside the housing.

8. The discharge lamp of claim 1 wherein the ultraviolet source is an ultraviolet radioactive material.

9. The discharge lamp of claim 1 wherein the ultraviolet source is an ultraviolet light-providing electronic device.

10. The discharge lamp of claim 1 wherein the gas is a mercury vapor.

11. A projecting device, comprising:

a discharge lamp, including:

a housing;

a discharge vessel disposed in the housing and having an axis, wherein the discharge vessel is configured to hold a gas;

a first electrode having a first end disposed inside the discharge vessel along the axis; and

a second electrode having a second end disposed inside the discharge vessel along the axis and opposite to the first end;

an ultraviolet source disposed at a predetermined distance from the axis and configured to excite the gas;

an igniter coupled to the first electrode and the second electrode, wherein the igniter is configured to output a voltage to further excite the gas and to form a beam of light, wherein the voltage is greater than 10 kV; and

an optical machine coupled to the discharge lamp, wherein the optical machine is configured to receive the beam and form an image.

12. The projecting device claim 11 wherein the housing is a reflector encompassing the discharge vessel, and wherein the reflector is configured to reflect the beam to into the optical machine along an optical path.

13. The projecting device of claim 11 wherein the ultraviolet source is disposed inside the housing.

14. The projecting device claim 13 wherein the ultraviolet source is disposed adjacent to the discharge vessel.

15. The projecting device of claim 13 wherein the ultraviolet source is disposed between the discharge vessel and the reflector.

16. The projecting device of claim 13 wherein the ultraviolet source is disposed on the reflector.

17. The discharge lamp claim 11 wherein the ultraviolet source is disposed outside the housing.

18. The projecting device of claim 11 wherein the gas is a mercury vapor.

19. A discharge lamp comprising a vessel disposed within a housing, wherein the discharge vessel is configured to contain a gas, the discharge lamp comprising:

a first electrode and a second electrode inside the vessel;

means for exciting the gas with UV energy; and

means for providing a voltage greater than 10 kV to the first and second electrodes to form a light beam.