Patent ID: 7259743

Claim:
A system for driving columns of a liquid crystal display comprising: logic circuitry operating in a supply path between a first and a second supply voltage with said first supply voltage higher than said second supply voltage, said logic circuitry being capable of generating first logic signals and second logic signals whose value is equal to said first or second supply voltage; elevator devices coupled to said logic circuitry and operating in a supply path between a third supply voltage greater than said first supply voltage and said second supply voltage, said elevator devices being capable of raising the value of said second logic signals; a first and a second pair of transistors having different supply paths and having an output terminal in common, said first and second pair of transistors being associated with said elevator devices and said logic circuitry to determine the drive signal of a column, wherein said elevator devices are coupled to one of said pairs of transistors; and turnoff circuitry coupled to said elevator devices, said turnoff circuitry being capable of keeping one of said two pairs of transistors in the turnoff state in the period of time of a frame when the other of said two pairs of transistors is operative.