Patent ID: 9099045
Filing Date: 2015-08-04
Classification: G09G

Abstract:
1. A backlight apparatus for controlling a backlight wherein light emitting devices (LEDs) for emitting light of a plurality of colors and a switching device for switching on or off light emission of said light emitting devices are provided for divisional regions formed by division of a lighting region such that a light emission luminance can be varied for the divisional regions, said backlight apparatus comprising: light emission luminance control means for varying a pulse width of a pulse signal to be supplied to a switching device in a first of the divisional regions to control the light emission luminance of the light emitted by a plurality of LEDs of the first divisional region, the plurality of LEDs being configured to emit light of the plurality of colors; current value storage means for storing, for the first divisional region, current values of currents to be supplied to the plurality of LEDs, the current values being determined such that a whiteness and the light emission luminance of the light emitted by the plurality of LEDs become equal to predetermined values; and current control means for controlling a power supplying means for supplying the currents to the plurality of LEDs so that the currents become equal to the current values stored in said current value storage means, wherein the switching device is configured to switch the plurality of LEDs in response to a same signal, the same signal being the pulse signal, wherein the plurality of LEDs includes a first LED configured to emit light of a first color and a second LED configured to emit light of a second color, wherein the light emission luminance control means is configured to adjust the light emission luminance of the light emitted by the plurality of LEDs from a first luminance value to a second luminance value by controlling the switching device to adjust a same rate at which the plurality of LEDs switch on and off from a first same rate value to a second same rate value, the first luminance value having a corresponding first chromaticity and the second luminance value having a corresponding second chromaticity, and wherein the current control means is configured to control chromaticity from the first luminance value to the second luminance value by providing current values to the first LED and the second LED that are different for at least one of the first chromaticity or the second chromaticity.