Patent ID: 8786847

Claim:
Light measuring apparatus including an enclosure housing supporting a light energy detector, a controller and a distance measuring device for measuring luminous intensity, as measured in candelas, of a source of light of a distant target comprising: the enclosure housing, having a first end, a lens system including an objective lens and a light energy detector aligned on a single light path extending from the objective lens, the light energy detector having an electronic communication conduit and the light energy detector mounted to receive light energy directed along the single light path from the objective lens; an infrared detector carried in the enclosure, a pick off filter located in the enclosure, the pick off filter located such that infrared component of an incoming light beam entering the apparatus through the objective lens is directed to the infrared detector; a light metering valve located in the enclosure proximate the focal surface location of the objective lens to selectively control light directed along the single light path extending from the objective lens of the enclosure; the controller including a digital processor in communication with the light energy detector through the electronic communication conduit; the distance measuring device having electronic communication capability in communication with the controller, the distance measuring apparatus having a receiving energy pulse path located on the single light path extending from the objective lens of the light measuring apparatus; the distance measuring device comprising a laser diode for projecting a series of pulsed light signals from the first end of the enclosure to the distant target; a lens at the first end of the enclosure in front of the laser diode and adjacent the objective lens through which the series of pulsed light signal are projected; the infrared detector receiving reflected pulses of light reflected from the distant target; an algorithm for comparing the travel time of pulses sent from the light meter to travel time distances over a measured period of time to determine the distance to the target object; whereby luminous intensity of a distant source of light, measured in candelas, is determined by using the digital processor of the controller to calculate luminous intensity from illuminance and distance measurements.