Lensed luminaire with lens brightness control and method

• Main Author: NGAI; PETER Y. Y
• Format: Patent
• Language: English
• Published: 09.03.1993
• Subjects: BLASTING; FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMSTHEREOF; HEATING; INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21Sand F21V, RELATING TO THEFORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THELIGHT EMITTED; INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21Sand F21V, RELATING TO USESOR APPLICATIONS OF LIGHTING DEVICES OR SYSTEMS; LIGHTING; MECHANICAL ENGINEERING; NON-PORTABLE LIGHTING DEVICES; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHERARTICLES, NOT OTHERWISE PROVIDED FOR; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLEEXTERIORS; WEAPONS

A luminaire, and typically an indirect luminaire, is provided with at least one visible lens element or other light transmissive media, the observable brightness of which is intended to enhance the performance of the luminaire in terms of providing a psychologically pleasing lighting environment. The brightness induced in the lens element is controlled by directing source light to the lens through a confined indirect light path provided by reflector components within the luminaire. Additionally, a light shield is provided internally of the luminaire to prevent direct source light from reaching the lens element. Preferably, at least one of the reflector components in the indirect light path is a diffuse reflector such that source light incident on the lens element is diffuse light. The amount of diffused source light reaching the lens element along the indirect light path is controlled by adjusting the size of an aperture disposed in the light path; any contributions to lens brightness from light reflected back from interior wall surfaces can be controlled or eliminated, if needed or desired, by a separate light shield element provided for this purpose. In accordance with the invention, the level of lens brightness can readily be controlled and the effects of the surrounding mounting environment for the fixture on lens brightness minimized or eliminated. Also eliminated will be the potential for hot spots on the lens, while overall uniformity of lens brightness will be improved.