Patent ID: 6914389
Filing Date: 2005-07-05
Classification: G02B

Abstract:
1. A direct-type back light module with photo sensors comprising: a housing with a transparent top surface; a first lamp installed in the housing; a second lamp arranged in parallel with the first lamp and installed in the housing; a first lamp driving loop for driving the first lamp to emit light; a second lamp driving loop for driving the second lamp to emit light; a first photo sensor installed in the housing for detecting the illumination of the first lamp; a second photo sensor installed in the housing for detecting the illumination of the second lamp; and a comparative and arithmetic unit; wherein the first and second photo sensors are employed to respectively detect the illuminations of the first and second lamps, respectively generate a first signal and a second signal and respectively transmit the first and second signals to the comparative and arithmetic unit as the first and second lamp driving loops respectively supply a first lamp current and a second lamp current to respectively drive the first and second lamps to emit light, and the comparative and arithmetic unit is employed to generate and transmit a first feedback signal and a second feedback signal respectively to the first and second lamp driving loops for adjusting the first and second lamp currents, respectively, to achieve an uniform illumination of both the first and second lamps.