High pressure mercury discharge lamp
AssigneeU.S. Philips Corporation
InventorHanns E. Fischer
Life of this patent
Estimating the term…
Abstract
The high pressure mercury discharge lamp comprises a quartz glass lamp vessel (1) having a region (2) surrounding a discharge space (3), spaced-apart tungsten electrodes (4) defining a discharge path (5) disposed in the lamp vessel, and connected to current conductors (6) which extend from the lamp vessel to the exterior and a filling of mercury, rare gas and bromine. The lamp has an operating pressure of at least about 200 bar. The discharge space (3) is spheroidal in shape and has specified dimensions. The lamp consumes a power of 70 to 150 W. The lamp has favourable properties which render the lamp suitable for use in optical systems, e.g. for projection purposes.
Claims17
A high pressure mercury discharge lamp, comprising:
- a quartz glass lamp vessel having a region surrounding a discharge space;
- spaced-apart tungsten electrodes disposed in the lamp vessel and defining a discharge path D.sub.p current conductors connected to said electrodes and which extend through the lamp vessel to the exterior;
- a filling of at least 0.2 mg Hg/mm.sup.3, 10.sup.-6 - 10.sup.-4 .mu.mol Br/mm.sup.3 and a rare gas in the discharge space,
- the discharge space being spheroidal in shape, having a dimension S in the direction of the discharge path which is
- S (mm)=e*D.sub.i, wherein
- e is in the range of 1.0-1.8,
- D.sub.i (mm)=f*(3.2+0.011(mm/W)*P(W)), wherein D.sub.i is the largest inside diameter of the discharge vessel transverse to the discharge path,
- f has a value in the range of 0.9-1.1,
- P is the power consumed at nominal operation, which is in the range of 70-150 W,
- the lamp vessel having in the region surrounding the discharge space a convex outer surface, which in a plane in which D.sub.i is situated has an outside diameter D.sub.o which is D.sub.o .gtoreq.3.2+0.055(mm/W)*P(W), and
- the length of the discharge path D.sub.p is in the range of 1.0-2.0 mm.
A high pressure mercury lamp, comprising:
- a) a lamp vessel having a portion enclosing a spheroidal discharge space having a volume, said portion having (i) an internal length dimension "S" defining a major axis of said spheroidal discharge space, (ii) a largest internal diameter "D" transverse to said length dimension defining a minor axis of said spheroidal discharge space, and (iii) a convex outer surface with an outside diameter "D.sub.o " in the plane including D.sub.i ;
- b) a pair of opposing discharge electrodes within said discharge space between which a discharge is maintained during lamp operation, said electrodes having distal tips aligned on said major axis of said discharge space and separated by a distance "D.sub.p " defining the length of the discharge path between said distal tips;
- c) means for connecting said discharge electrodes to a source of electric potential outside of said discharge vessel;
- and
- d) a filling within said discharge space comprising a rare gas, at least 0.2 mg Hg/mm.sup.3 and 10.sup.-6 - 10.sup.-4 .mu.mol Br/m.sup.3 of the volume of the discharge space, wherein
- (i) said lamp during nominal lamp operation consumes a power "P" of between about 70 and about 150 W,
- (ii) the discharge path length D.sub.p is in the range 1.0-2.0 mm,
- (iii) the length dimension S is defined by the equation S(mm)=e*D.sub.i, where
- e is in the range 1.0-1.8 and
- D.sub.i (mm)=f*(3.2+0.011(mm/W)*P(W)), where
- f has a value in the range 0.9-1.1, and
- (iv) the outside diameter D.sub.o is defined by the equation
- D.sub.o (mm).gtoreq.3.2+0.055 (mm/W)*P(w).
Dependencies are inferred from the claim text.