Patent ID: 7859527

Claim:
A display device which has plural pixels aligned in a matrix form on a substrate, comprising: each pixel having at least a first transistor, a second transistor, an image signal memory, an electro optic medium and a common electrode, and wherein each pixel is connected to at least an image signal line, a scanning signal line and a reference voltage line, wherein either a drain or a source and the other of said source or said drain of said first transistor are respectively connected to said image signal line and a gate of said second transistor; a gate of said first transistor is connected to said scanning signal line; either a drain or a source and the other of said source or said drain of said second transistor are respectively connected to said electro optic medium and said reference voltage line; said image signal memory is connected to said gate of said second-transistor and said common electrode; said electro optic medium is connected to said drain or said source of said second transistor and said common electrode, said electro optic medium maintains a displayed image after power is switched off, a voltage of said reference voltage line sequentially takes at least three different voltages including a voltage similar to a voltage of said common electrode, and said electro optic medium has at least two image displays that are independently written in said electro optic medium in an image re-writing period including a first scanning interval for rewriting said electro optic medium from black to white and a second scanning interval for rewriting said electro optic medium from white to black, and a plurality of pixels are rewritten in the image re-writing period, and for the first scanning interval, only scanning lines for pixels to be written from black to white are turned on, and for the second scanning interval, only scanning lines for pixels to be written from white to black are turned on.