Patent ID: 6356028
Filing Date: 2002-03-12
Classification: G09G

Abstract:
A screen drive system comprising:a matrix including rows and columns of cathodic emission devices that are driven one full row at a time; and a set of switching devices, each switching device configured to regulate current from a current source to a respective cathodic emission device throughout a time necessary to drive all rows of the matrix; wherein: A) the coincidence circuit includes: 1) a first memory circuit connected to a row wire and to a column wire, and configured to store a data item transmitted on the column wire, 2) a transfer circuit configured to controllably transfer the data item stored in the first memory circuit to a second memory circuit, 3) the second memory circuit configured to store the data item transferred by the transfer circuit, and 4) a current-control circuit configured to control transmission of a defined current to the respective cathodic emission device as a function of the data item stored in the second memory circuit; B) the system further comprises a central control circuit that is configured to sequentially control scanning of the rows of the matrix and send the data item on each column each time a row is driven so that the data item is then stored in the first memory circuit, and to control the transfer circuit of each coincidence circuit to transfer the data item from the first memory circuit to the second memory circuit at an end of a frame scan of the matrix.