High-pressure discharge lamp

• US 20070052363A1
• Filed: 12/05/2003
• Published: 03/08/2007
• Est. Priority Date: 12/17/2002
• Status: Abandoned Application

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Schöller, Klaus
• Application Number:
  US10/539,695
• Publication Number:
  US 20070052363A1
• Time in Patent Office: Days
• US Class Current: 313/633
• CPC Class Codes: H01J 61/30 Vessels; Containers
• CPC Class Codes: H01J 61/34 Double-wall vessels or containers
• CPC Class Codes: H01J 61/35 provided with coatings on the walls thereof; Selection of materials for the coatings using coloured coatings H01J61/40; using luminescent coatings H01J61/42
• CPC Class Codes: H01J 61/40 by light filters; by coloured coatings in or on the envelope

Abstract

A high-pressure discharge lamp (1) comprising at least one burner (2) having a discharge space, and comprising two electrodes extending in said discharge space, a gas filling in the discharge space containing at least an inert gas and a suitable metal halide mixture, and comprising an outer bulb (3) which is attached to the burner (2) and the basic material of which is doped with an absorbing material, the high-pressure discharge lamp (1) comprising at least one interference filter (6) which reflects predominantly in the wavelength range of 400 to 550 nm, and which is arranged directly on at least a part of the outer surface of the outer bulb (3), and the outer bulb (3) being doped with a material that is absorbing for wavelengths <550 nm.

Claims

1. A high-pressure discharge lamp (1) comprising at least

a burner (2) having a discharge space,

two electrodes extending in said discharge space,

a gas filling in the discharge space comprising at least an inert gas and a suitable metal halide mixture, and

an outer bulb (3) which is attached to the burner (2) and the basic material of which is doped with absorbing material, characterized in that the high-pressure discharge lamp (1) comprises at least one interference filter (6) which reflects predominantly in the wavelength range of 400 to 550 nm and which is arranged directly on at least a part of the outer surface of the outer bulb (3), which outer bulb (3) is doped with a material that is absorbing for wavelengths <

550 nm.

2. A high-pressure discharge lamp (1) as claimed in claim 1, characterized in that the basic material of the outer bulb (3) is predominantly composed of SiO₂ and contains Cr, Zn, Fe, Sb, Ti or Cr oxide, with chromium being in the trivalent state as CrIII, or predominantly in the hexavalent state as CrVI, preferably in a quantity up to 0.7%, Zn oxide, preferably 1.0%, Al oxide, preferably Al₂O₃, Fe oxide, Sb oxide, Ti oxide and/or their mixtures.

3. A high-pressure discharge lamp (1) as claimed in claim 1, characterized in that the basic material of the outer bulb (3) comprises at least 0.024 to 0.5% Cr₂O₃, 0.034 to 1.0% ZnO and Al₂O₃.

4. A high-pressure discharge lamp (1) as claimed in claim 1, characterized in that a tubular outer bulb (3) is attached, at least with one end, to the burner (2), and at least at the surfaces of the regions that are used to attach the burner (2) to the outer bulb (3), no light-absorbing means and/or interference filters (6) are provided.

5. A high-pressure discharge lamp (1) as claimed in claim 1, characterized in that with regard to the wavelength range of 600 to 800 nm, the light transmittance of the materials of the outer bulb (3) is >

60% and the light transmittance of the interference filter (6) is >

90%.

6. A high-pressure discharge lamp (1) as claimed in claim 1, characterized in that the overall layer thickness of the interference filter (6) ranges between 800 and 2800 nm.

7. A high-pressure discharge lamp (1) as claimed in claim 1, characterized in that the interference filter (6) is composed of a plurality of layers, the layer structure being such that a layer having a higher refractive index alternates with a layer having a lower refractive index, the layer having the lower refractive index preferably being predominantly composed of SiO₂ and the second layer being composed of a material having a higher refractive index than SiO₂, said layer preferably being composed of ZrO₂.

8. A high-pressure discharge lamp (1) as claimed in claim 7, characterized in that the second layer is composed of a material selected from the group consisting of titanium oxide, tantalum oxide, niobium oxide, hafnium oxide, silicon nitride, very preferably zirconium oxide ZrO₂, or a mixture of these materials.

9. A high-pressure discharge lamp (1) as claimed in claim 1, characterized in that the metal halide mixture is composed of 40 to 80 wt. % NaI, 0 to 40 wt. % ScI and 0 to 60 wt. % TI.

10. A high-pressure discharge lamp (1) as claimed in claim 1, characterized in that the lumen output of the light emitted by the high-pressure discharge lamp (1) is at least 60 lm/W, preferably at least 70 lm/W and very preferably at least 80 lm/W.

11. A light system for motorcars comprising at least a high-pressure discharge lamp (1) as claimed in claim 1.