Patent ID: 7030850

Claim:
A signal drive circuit which drives signal lines of an electro-optical device having pixels specified by a plurality of scan lines and a plurality of signal lines which intersect each other, based on image data, the signal drive circuit comprising: a line latch which latches the image data in a horizontal scanning cycle; a drive voltage generation circuit which generates a drive voltage for each signal line based on the image data latched in the line latch; and a signal line drive circuit which drives each signal line based on the drive voltage generated by the drive voltage generation circuit; a shift register which temporarily holds image data necessary for one horizontal scan to be latched by the line latch, and includes flip-flops connected to each other and corresponding to the signal lines, the image data being input sequentially in a unit of a given bits; and a data transfer circuit provided in each block to receive and transfer image data to flip-flops in an adjacent block when high impedance control is performed on a block in which the data transfer circuit is provided, each block being provided in units of the given plural number of the signal lines, wherein the signal line drive circuit determines whether to perform high impedance control for an output of the signal line drive circuit in units of a given plural number of the signal lines, and wherein the data transfer circuit does not transfer the image data to flip-flops in an adjacent block when high impedance control is not performed on a block in which the data transfer circuit is provided.