Patent ID: 7495668

Claim:
A display memory circuit comprising: a drawing memory which stores data and in which at least a portion of said data is rewritten into new data at a third timing, said third timing being between a first timing and a second timing that are each a start timing of a display frame; and a dynamic display memory which is connected with said drawing memory, which latches said data in response to said first timing and continues to hold said data between said first timing and said second timing, wherein said drawing memory is partially disconnected from said dynamic display memory from said third timing to said second timing; said drawing memory comprising a plurality of first memory cells arranged in a matrix; said dynamic display memory comprising: a plurality of second memory cells arranged in a matrix, and a transfer transistor provided for each of said plurality of second memory cells, said plurality of transfer transistors being turned on to connect said plurality of first memory cells and said plurality of second memory cells at said first timing, respectively, and when said portion of said data is rewritten at said third timing, said plurality of transfer transistors corresponding to the rewritten portion being turned off at said third timing; each of said plurality of second memory cells comprising: said transfer transistor; a memory capacitor connected with said transfer transistor to receive and hold a corresponding one of bits of said data; a drive transistor driven based on the bit stored in said memory capacitor; and a read transistor which is connected with said drive transistor and a read bit line to transfer the bit stored in said memory capacitor to said read bit line such that said held data is displayed on said display section, wherein each of said plurality of second memory cells further comprises a buffer connected between said transfer transistor and a corresponding one of said plurality of first memory cells, and wherein said data is transferred via said buffer without using said read bit line.