Lamp with shaped wall thickness, method of making same and optical apparatus

Abstract

A lamp, a method of making a bulb for a lamp and an optical apparatus are disclosed. The lamp may include an anode and cathode disposed within a bulb. The bulb may include an optically refractive wall that is rotationally symmetric about an axis. A thickness of the wall may decrease with increase in azimuthal angle between an equatorial plane of the bulb and a point on the bulb's surface. The apparatus may include the lamp and an ellipsoidal reflecting surface. An alternative apparatus may include an ellipsoidal reflecting surface and a lamp having an anode and cathode within a bulb. A gap between the anode and cathode may be proximate a focus of the reflecting surface. The bulb may include an optically refractive wall configured such that a 0.24/0.13 NA power ratio for bulb light coupled to the interior ellipsoidal reflecting surface is between about 3.0 and about 3.3.

Dependencies are inferred from the claim text.