OPTIMIZED HID ARC TUBE GEOMETRY

摘要

The geometry of a High Intensity Discharge (HID) arc tube is controlled to improve lamp color control and temperature distribution. In some embodiments, conical sections located at the transition zones near the electrodes are included to provide tunnel-like body-leg interface portions. The body-leg interface portions are shaped so as to advantageously control the temperature distribution along the internal surface of the discharge chamber wall so that it monotonically decreases resulting in a stable local cold spot location at the body-leg interface.

主权项

1. An arc tube, comprising:
a ceramic wall body defining a discharge chamber therein for enclosing a metal-halide dose having a wall thickness T, the ceramic wall body comprising:
a first curved portion and an opposing, second curved portion, wherein a dimension R3 represents a radius of curvature of the first curved portion and the second curved portion;a first conical portion after the first curved portion and a second conical portion after the second curved portion, wherein a dimension L3 represents a length of the first and second conical portions, and wherein a dimension α represents a cone half angle of the first conical portion and of the second conical portion; anda first body-leg transition portion having a first body-leg interface after the first conical portion, and a second body-leg transition portion having a second body-leg interface after the second conical portion, wherein a dimension R4 represents a radius of curvature of the first body-leg transition portion and of the second body-leg transition portion, and wherein a dimension L1 represents the distance between the first body-leg transition portion and the second body-leg transition portion; and wherein the ceramic wall body has a dimension D2 representing a maximum diameter of the discharge chamber and the following relationships are true: 0.5