Patent ID: 8466857

Claim:
A portable communication terminal, comprising: a communication unit for transmitting and receiving data via a communications network; a storage unit for storing the data and computer executable instructions for performing operations of the portable communication terminal; an operations unit configured to receive a user's input to perform one or more operations of the portable communications terminal; a battery for supplying power to portable communications terminal; a display for displaying images; and a controller configured to display images on the display and to adjust a luminance level of the display based on an estimated power consumption value and a remaining level of the battery, wherein the controller is further configured to: determine whether a remaining battery level of the battery falls within one of a first battery level range or a second battery level range, wherein the first battery level range is higher than the second battery level range; determine whether an estimated power consumption value falls within one of a first power consumption range or a second power consumption range, wherein the first power consumption range is higher than the second power consumption range; when the remaining battery level is determined to fall within the first battery level range and the estimated power consumption value is determined to fall within the first power consumption range, the controller adjusts the luminance level to a first luminance level; when the remaining battery level is determined to fall within the first battery level range and the estimated power consumption value is determined to fall within the second power consumption range, the controller adjusts the luminance level to a second luminance level; when the remaining battery level is determined to fall within the second battery level range and the estimated power consumption value is determined to fall within the first power consumption range, the controller adjusts the luminance level to a third luminance level, and when the remaining battery level is determined to fall within the second battery level range and the estimated power consumption value is determined to fall within the second power consumption range, the controller adjusts the luminance level to a fourth luminance level, wherein the first luminance level is lower than the second luminance level and the third luminance level is lower than the fourth luminance level.