Patent ID: 8810611

Claim:
A liquid crystal display device comprising: a liquid crystal display panel for displaying an image by having liquid crystal that changes orientation in accordance with application of a voltage; a backlight unit housing a Pulse Width Modulation (PWM) light-modulating light source configured to emit light to be supplied to the liquid crystal display panel; a control unit configured to control the liquid crystal display panel and the backlight unit; and a first temperature sensor for measuring the temperature of the liquid crystal, wherein the liquid crystal is included in the liquid crystal display panel and is disposed between two substrates; a first electrode and a second electrode are aligned opposite one another on a surface of one of the two substrates that faces the liquid crystal; liquid crystal molecules included in the liquid crystal are of a positive type and are oriented so that a major-axis direction thereof is made to follow along a vertical direction of the two substrates in a case where a voltage is not applied to the two electrodes; the control unit is configured to acquire response speed data of an orientation change of the liquid crystal molecules in the liquid crystal, and vary a drive frequency of the PWM light-modulation signal in accordance with the response speed data, the control unit includes, a histogram unit configured to generate histogram data showing a frequency distribution for gradation by forming a histogram from picture data, and a storage section configured to store an occupancy ratio threshold value, the control unit being configured to divide all gradations of the histogram data into gradation ranges and judge whether an occupancy ratio in at least one of the gradation ranges among the divided gradation ranges exceeds or is equal to or less than the occupancy ratio threshold value, wherein in a case where the occupancy ratio exceeds the occupancy ratio threshold value, the control unit is configured to adjust the drive frequency to be less than the drive frequency in a case where the occupancy ratio is equal to or less than the occupancy ratio threshold value, in a case where the occupancy ratio is equal to or less than the occupancy ratio threshold value, the control unit is configured to adjust the drive frequency to be greater than the drive frequency in a case where the occupancy ratio exceeds the occupancy ratio threshold value, and the control unit is configured to vary at least one of the gradation ranges and the occupancy ratio threshold value of the occupancy ratio in accordance with the temperature data of the first temperature sensor.