Abstract: A simultaneous precharge type display device source driver includes supply control circuits each of which is provided on each of source bus lines. Each of the supply control circuits receives (a) a precharge control signal for precharging each of the source bus line and (b) a sampling control signal for writing data, which should be written on pixels, onto the source bus line. The one of two switches turns ON in response to the precharge control signal and the sampling control signal. The other of the switches turns ON in response to the sampling control signal. In the sampling operation, both the switches are turned ON so as to quicken the writing operation. In the precharge operation, the other switch does not operate, so that it is possible to reduce the power consumption.

Abstract: A level-shifter is combined with a bi-directional shift register. The level shifter turns a start signal of the bi-directional shift register to be an enable signal, and (i) activates a level shifting section by supplying a stationary current, during a period in which the enable signal is HIGH, while (ii) deactivates the level shifting section by cutting off the stationary current, during a period in which the enable signal EN is LOW. With this, it is possible to reduce unnecessary current consumption by a level shifter provided for a signal which does not frequently change, such as a shifting direction switching signal for which the bi-directional shift register is provided. At the same time, when such a signal changes, the change is followed with no time lag.

Abstract: A level-shifter is combined with a bi-directional shift register. The level shifter turns a start signal of the bi-directional shift register to be an enable signal, and (i) activates a level shifting section by supplying a stationary current, during a period in which the enable signal is HIGH, while (ii) deactivates the level shifting section by cutting off the stationary current, during a period in which the enable signal EN is LOW. With this, it is possible to reduce unnecessary current consumption by a level shifter provided for a signal which does not frequently change, such as a shifting direction switching signal for which the bi-directional shift register is provided. At the same time, when such a signal changes, the change is followed with no time lag.

Abstract: A simultaneous precharge type display device source driver includes supply control circuits each of which is provided on each of source bus lines. Each of the supply control circuits receives (a) a precharge control signal for precharging each of the source bus line and (b) a sampling control signal for writing data, which should be written on pixels, onto the source bus line. The one of two switches turns ON in response to the precharge control signal and the sampling control signal. The other of the switches turns ON in response to the sampling control signal. In the sampling operation, both the switches are turned ON so as to quicken the writing operation. In the precharge operation, the other switch does not operate, so that it is possible to reduce the power consumption.