The present invention is aimed at appropriately suppressing display failure such as a tailing phenomenon and the like in a normally white type liquid crystal panel. A driver (3) supplies a drive voltage in conformity with an image signal received by an image signal processing circuit (1), to a liquid crystal panel (4). A histogram detector (5) detects a histogram representing the relationship between the signal level of the image signal received by the image signal processing circuit (1) and the number of pixels. A CPU (6) calculates, based on the histogram detected by the histogram detector (5), a first proportion of the number of pixels (on the white side) whose signal level is equal to or greater than a first defined value, to the total number of pixels of the histogram and a second proportion of the number of pixels (on the black side) whose signal level is equal to or smaller than a second defined value that is smaller than the first defined value, to the total number of pixels of the histogram. An amplifier (2) corrects the lower limit of the drive voltage that the driver (3) supplies to the liquid crystal panel (4) in accordance with the first proportion of white side pixels and second proportion of black side pixels calculated by CPU (6).