Patent ID: 8872435

Claim:
A light comprising: (a) a base unit; (b) an arm extending from the base unit; and (c) a lamp head coupled to the arm, the lamp head comprising: (i) an LED configured to provide light based on an input drive current, (ii) an optical mixing element configured to collect the light produced by the LED, (iii) a zoom lens element configured to adjust an output size of a spot generated by the light collected in the mixing element, (iv) a rotary member, (v) a fixed member, wherein the rotary member is rotatable relative to the fixed member to adjust the linear position of the zoom lens element relative to the LED to thereby adjust the output size of the spot generated by the light collected in the mixing element, (vi) a sensor configured to sense the angular position of the rotary member relative to the fixed member, and (vii) a controller receiving DC power from the base unit through the arm, the controller configured to set the input drive current for the LED to control an output light density of the spot in response to an operator selected input, the controller further configured to adjust the output light density of the spot in response to a signal from the sensor indicating a change in the angular position of the rotary member relative to the fixed member.