High intensity spotlight

Abstract

A light projecting apparatus consists of a concave, substantially prolate-spheroidal reflector having a major axis coincident with the optical axis of the apparatus and a metal halide high intensity discharge source positioned at a first focal point of the reflector and inclined with respect to the optical axis of the apparatus at an angle of approximately 30°. .Iadd.

What is claimed is:  .[.1. A light projecting apparatus comprising a concave, substantially prolate-spheroidal reflector having on the major axis thereof a first and a second focal point within and remote from the reflector respectively, a high intensity halide source positioned at said first focal point, the source having a opposed electrodes defining a source axis which is inclined with respect to said major axis at an angle between 25° and 35°..]. .[.2. The light projecting apparatus of claim 1 wherein the intersecting source axis and major axis define a substantially vertical plane..]. .[.3. The light projecting apparatus of claim 1 wherein the reflector has a front circular opening lying in a plane perpendicular to said major axis, the radius of said circular opening being less than the semi-minor axis of a prolate-spheroid of the same dimension as the reflector..].  .[.4. The light projecting apparatus of claim 1 wherein the reflector has a rear circular opening, the central portion of said opening lying in a plane normal to a line passing through the first focal point, said line inclined with respect to said major axis at approximately 30°..]. .[.5. The light projecting apparatus of claim 4 wherein said rear circular opening intersects a solid angle of less than 0.4 steradians when measured from said first focal point..]. .[.6. The light projecting apparatus of claim 1 wherein said source axis is inclined with respect to said major axis at an angle of approximately 30°..]. .[.7. A light projecting apparatus comprising a concave, substantially prolate-spheroidal reflector having on the major axis thereof a first and a second focal point within and remote from the reflector respectively, said reflector having a front circular opening lying in a plane perpendicular to said major axis, the radius of said circular opening being less than the semi-minor axis of a prolate-spheroid of the same dimension as the reflector, the reflector having a rear circular opening whose central portion lies in a plane normal to a line passing through said first focal point, said line inclined with respect to said major axis at approximately 30°, said rear circular opening intersecting a solid angle of 0.4 steradians when measured from said first focal point, a high intensity halide source positioned at the first focal point, the source having a first and a second spaced-apart opposed electrode, the line passing through the length of said electrodes defining a source axis, said source axis being inclined with respect to said major axis at an angle between 25° and 35°, said source axis and said major axis lying in a substantially vertical plane, said first electrode being wholely above said major axis and extending through said rear circular opening, said second electrode being wholely below said major axis and extending through said front circular opening..]. .Iadd. 8. A spotlight for projecting light comprising 
     
        quarter times the length of said arc source. .Iaddend..Iadd. 9.  A spotlight as in claim 8 wherein said rear circular opening intersects a solid angle of less than 0.4 steradians when measured from the first focal point. .Iaddend..Iadd. 10. A spotlight as in claim 8 wherein said source axis is inclined with respect to said major axis at an angle of approximately 30°. .Iaddend..Iadd. 11. A spotlight for projecting light comprising a concave, substantially prolate-spheriodal reflector having on the major axis thereof a first and a second focal point within and remote from the reflector respectively, said reflector having a front circular opening lying in a plane perpendicular to said major axis, the radius of said circular opening being less than the semi-minor axis of a prolate-spheriod of the same dimension as the reflector, the reflector having a rear circular opening whose central portion lies in a plane normal to a line passing through said first focal point, said line inclined with respect to said major axis at approximately 30°, said rear circular opening intersecting a solid angle of 0.4 steradians when measured from said first focal point, a high intensity halide source positioned at the first focal point, the source having a first and a second spaced-apart opposed electrode, the line passing through the length of said electrodes defining a source axis, said source axis being inclined with respect to said major axis at an angle between 25° and 35°, said source axis and said major axis lying in a substantially vertical plane, said first electrode being wholely above said major axis and extending through said rear circular opening, said second electrode being wholely below said major axis and extending through said front circular opening, and a controlled aperture positioned at said second focal point. .Iaddend.