Patent ID: 9741311
Date: 2017-08-22
CPC Classifications: G09G

Claim:
1. A data line driver that drives a data line of a display panel by generating gradation voltage based on image data, the data line driver comprising: a first data storage unit and a second data storage unit that are connected in series and are configured to sequentially store successively supplied image data; a digital-to-analog converter (DAC) configured to perform digital-to-analog (D/A) conversion on the image data stored in the first data storage unit and output an analog image signal; an amplifier configured to amplify the image signal output from the DAC to generate an output signal, and supply the output signal to a gradation voltage output terminal; a subtracter configured to calculate a difference value between the image data stored in the first data storage unit and the image data stored in the second data storage unit; a timing pulse generator configured to generate a timing pulse based on the difference value calculated by the subtracter; a charge supply circuit configured to supply a charge to the gradation voltage output terminal in accordance with the timing pulse generated by the timing pulse generator; and an action table storage unit configured to store therein an action table and output pulse width data corresponding to the difference value calculated by the subtracter, the action table being a table in which pulse width data indicating pulse widths of the timing pulse are set in correspondence with a plurality of the difference values, and wherein the timing pulse generator generates the timing pulse having a pulse width set based on the pulse width data output from the action table storage unit, wherein the charge supply circuit includes a plurality of P channel transistors that are connected in parallel between a high potential-side power supply potential and the gradation voltage output terminal and a plurality of N channel transistors that are connected in parallel between the gradation voltage output terminal and a low potential-side power supply potential, and the data line driver further includes: a second action table storage unit configured to store therein a second action table and output a signal indicating selection information corresponding to the difference value calculated by subtracter, the second action table being a table in which the selection information regarding transistors selected when the charge supply circuit is operated are set in correspondence with a plurality of the difference values; and a transistor driving circuit configured to turn on at least one transistor selected by the signal output from the second action table storage unit in accordance with the timing pulse generated by the timing pulse generator.