Patent ID: 8368635
Filing Date: 2013-02-05
Classification: G09G

Abstract:
1. A source driver comprising: an inverting portion which inverts polarity of a voltage according to image data with respect to a reference potential at a predetermined cyclic period for each column of an active matrix liquid crystal display (LCD) panel; and a plurality of amplifiers each having a voltage follower for outputting, at the predetermined cyclic period, a drive voltage to a column terminal of the LCD panel through an output terminal in accordance with an output voltage of the inverting portion, wherein each of the plurality of amplifiers includes, a differential amplifying portion having a non-inverting input for receiving the output voltage of the inverting portion, first and second output amplifying portions for inputting an output voltage of the differential amplifying portion as input voltages, a connecting portion for connecting between an output of the first output amplifying portion and the output terminal, a first switch element for turning on or off a connection between an output of the second output amplifying portion and the output terminal, a second switch element for turning on or off a connection between the output terminal and a common line for the plurality of amplifiers, a third switch for turning on or off a connection between the output of the second output amplifying portion and an inverting input of the differential amplifying portion, and a fourth switch element for turning on or off a connection between the output terminal and the inverting input of the differential amplifying portion, and wherein, during a first predetermined period immediately after the polarity of the voltage according to the image data is inverted by the inverting portion, the first output amplifying portion is set to a high impedance state, the first and fourth switch elements are set to an off state, and the second and third switch elements are set to an on state, and during an period after the first predetermined period is ended and before the polarity of the voltage according to the image data is inverted again by the inverting portion, the first output amplifying portion is set to an amplifier operation state, the first and fourth switch elements are set to an on state, and the second and third switch elements are set to an off state.