Patent ID: 8436545
Filing Date: 2013-05-07
Classification: G03B,H04N,H05B

Abstract:
1. A light source apparatus comprising: a high pressure discharge lamp; a power supply apparatus that supplies an alternating current to the lamp, the power supply apparatus comprises a switching element; a control circuit that outputs a control signal to the power supply apparatus; the control circuit receives a timing signal for a switching timing of an area of a color wheel or a synchronization signal that is a time divisional signal for a refresh rate of a liquid crystal, controls a switching cycle of the switching element, and switches polarity of power supplied to the lamp; the lamp comprises a one electrode that faces an other electrode; when the lamp is horizontally arranged, the power supply apparatus sets a ratio A/B of an electric energy A to an electric energy B and supplies an alternating current, the polarity of which is synchronously changed according to the synchronization signal, wherein the electric energy B flows to the one electrode from the other electrode, the electric energy A flows from the one electrode to the other electrode; when the lamp is vertically arranged, the power supply apparatus sets an electric energy A′ that flows from one of the electrodes arranged in a lamp upper side to another one of the electrodes arranged in a lamp lower side to be smaller than electric energy B′ that flows from the electrode arranged in the lower side to the electrode arranged in the upper side, the power supply apparatus further sets a ratio A′/B′ of the electric energy A′ to the electric energy B′, wherein the ratio A′/B′ is smaller than the ratio A/B, and supplies an alternating current, the polarity of which is synchronously changed according to the synchronization signal.