Patent ID: 6447146
Filing Date: 2002-09-10
Classification: F21V,G02F

Abstract:
A back light apparatus for use with a large-area, flat-panel display, comprising:a) a housing having a light output region; b) an array of fluorescent lamps disposed within said housing; c) at least one ballast operatively connected to said array of fluorescent lamps; d) reflecting means located within said housing and proximate said array of fluorescent lamps; e) temperature control means comprising: i) at least one cooling zone across the width of said array of fluorescent lamps, said cooling zone comprising at least one variable speed fan associated therewith; ii) temperature sensing means proximate at least one lamp of said array of fluorescent lamps and adapted to sense the temperature within said housing; iii) controller means operatively connected to said at least one variable speed fan and said temperature sensing means to vary the speed of said at least one variable speed fan for maintaining the temperature within said housing within a predetermined range of temperatures; and f) light diffusing means located between said array of fluorescent lamps and said light output region.