Patent ID: 7268753

Claim:
An image brightness controlling apparatus comprising: a parameter selling portion for detecting the maximum and minimum values of the brightness of an input image signal and for setting the maximum and minimum values of an extended brightness range in response to the input image signal composed of a plurality of elements and a control signal; and a brightness range improving portion for outputting a luminance signal obtained by extending the brightness range of the input image signal, in response to the input image signal, the plurality of values output from the parameter setting portion, the predetermined maximum and minimum reference values of the brightness of the input image signal, and the maximum and minimum reference values of an extended brightness range, said brightness range improving portion comprising: a brightness parameter arithmetic unit for outputting a brightness parameter for the input image signal; a range comparator for comparing the brightness parameter with the maximum and minimum values of the brightness of the input image signal to determine which section the brightness parameter belongs to and output section information; a brightness signal arithmetic unit for outputting a plurality of brightness parameters in which brightness ranges of individual sections are extended, in response to the brightness parameter; and a range selector for receiving the plurality of brightness parameters in which the brightness ranges of individual sections are extended and the section information and selecting a brightness parameter corresponding to the section information among the received brightness parameters to obtain the luminance signal whose brightness range is extended.