Apparatus and method for maintaining synchronism between a picture signal and a matrix scanned array

摘要

A display apparatus for receiving a picture signal having video and synchronizing components includes a matrix of display cells arranged in an array of M columns by N rows. Display cells in the matrix are individually addressable by row and column signals so as to receive the video component of the picture signal in response thereto. A first shift circuit coupled to the matrix provides the column signals in response to a first clocking signal. A second shift circuit coupled to the matrix provides the row signals in response to a second clocking signal. A synchronizing detector or gate circuit coupled to the first and second shift circuits receives the synchronizing component of the picture signal and produces the second clocking signal in response to a preselected pointer signal from the first shift circuit. A phase locked loop circuit coupled to the first shift circuit receives the second clocking signal and produces the first clocking signal in response thereto.