Patent ID: 8009137
Filing Date: 2011-08-30
Classification: H05B

Abstract:
1. An image display apparatus comprising: a lighting unit which includes a lamp unit, and illuminates light onto a display screen; a power supply unit which supplies electric power to the lighting unit to drive the lamp unit of the lighting unit; a main circuit unit which outputs a brightness control signal which is provided to the power supply unit to control a brightness of the lighting unit, and controls the power supply unit; and a constant voltage generator which is provided between the main circuit unit and the power supply unit, and controls a magnitude of the brightness control signal which is output from the main circuit unit, to generate a constant voltage, wherein, upon detecting an over-current flowing in the lamp unit, the main circuit unit determines whether the detected over-current is an instantaneous over-current or a continuous over-current, and if the main circuit determines that the detected over-current is the instantaneous over-current, the main circuit outputs the brightness control signal to apply a corresponding voltage to the lamp unit according to a form of the over-current, and if the main circuit determines that the detected over-current is the continuous over-current, the main circuit activates the constant voltage generator so that the brightness control signal is controlled by the constant voltage generator.