Patent ID: 7262752
Filing Date: 2007-08-28
Classification: G02F,G09G,H05B

Abstract:
1. A system for a backlit display, comprising: a plurality of light emitting diodes connected together in series; a plurality of parallel elements connected in parallel with the plurality of light emitting diodes, and wherein the plurality of light emitting diodes are adapted to provide back lighting for a liquid crystal display; a current monitor connected with the plurality of light emitting diodes that measures an amount of current flowing from the plurality of light emitting diodes and generates a current flow signal; a temperature sensor in communication with the plurality of light emitting diodes to measure a temperature of the light emitting diodes and generate a temperature signal corresponding to the temperature; a voltage converter that supplies a current to the plurality of light emitting diodes as a function of the current flow signal, a commanded current signal, and the temperature signal, when in a first mode below a threshold temperature the voltage converter being in electrical communication with the plurality of parallel elements to automatically increase a voltage across a parallel element of the plurality of parallel elements based on the current flow signal, thereby causing the current to flow through the parallel element and around a light emitting diode of the plurality of light emitting diodes upon an open circuit failure of the light emitting diode and maintain a consistent brightness, and when in a second mode above a threshold temperature the voltage converter being configured to reduce the current to the plurality of light emitting diodes as a function of the temperature signal.