Patent ID: 6232946
Filing Date: 2001-05-15
Classification: G09G,H03M

Abstract:
An active matrix digital drive circuit for sampling a digital input signal having n parallel bits and for supplying analogue drive signals to a plurality of lines, the drive circuit comprising:a control shift register comprising a chain of control shift elements having respective outputs; anda driver stage associated with each of the control shift elements; each respective driver stage arranged so as to sample the input signal for a corresponding one of the lines and to supply a drive signal to the line under the control of the respective control shift element,wherein each of the driver stages incorporates a sample shift register including a chain of n sample shift elements having n inputs and controlled by the control shift register such that, in a sampling mode, the n bits of the input signal are supplied in parallel to the n inputs of the sample shift elements, and, in a shifting mode, the n bits stored by the sample shift elements are shifted along the sample shift register towards at least one output of the sample shift register, and a serial digital-to-analogue converter coupled to said output of the sample shift register for sequentially receiving the bits shifted along the sample shift register and for supplying the analogue drive signal to the corresponding line in dependence thereon.