Lighting systems and methods providing active glare control

Abstract

A light fixture includes a dimmable light source that emits light downwardly, and a downward-looking rangefinder proximate and operatively coupled with the light source. When the rangefinder detects an object at a measured height that exceeds a first threshold, the light source dims according to the measured height. A light fixture that provides illumination with active glare control for a lighted area includes one or more first light sources that emit high-angle light, and one or more dimmable second light sources that emit low-angle light, into the lighted area. The system also includes a camera that captures images of the lighted area, and a controller that is (a) operable to identify one or more activity locations within the lighted area from the images, and (b) operatively coupled to dim one or more of the light sources that illuminate the one or more activity locations.

Description

[0001] related application [0002] This application claims priority benefit of US Provisional Patent Application Serial No. 61 / 815715, filed April 24, 2013, and Serial No. 14 / 259778, filed April 23, 2014, which are hereby incorporated by reference. Background technique [0003] Glare is a common problem in nature and in many lighting situations. Sometimes glare is the result of the physical proximity of a light source to the object being viewed. Other times, the light source is not physically close to the object, but behind it so that the source is in the same field of view as the object with respect to the observer. Humans and certain animals have facial shapes and features such as eyebrows that form a natural glare shield so that high angle light (light forming a high angle relative to the horizontal) is not visually objectionable. For example, the effect of glare is easily observed outdoors during the early or late hours of a sunny day. When the observer or photographer...

AI Technical Summary

Problems solved by technology

[0004] Luminaires that direct high-angle light primarily downward may not present glare to observers who are not looking directly up at the luminaire, but such luminaires may illuminate only a small area

Other luminaires that direct light at high or low angles can illuminate a larger area, but can present glare to distant observers

In some cases, the observer must look at objects near the light source so that light from the source may be in the observer's field of view

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