Patent ID: 8199129

Claim:
A method for determining a contact of a display device, comprising: receiving a sensing data signal from each light sensor of a matrix of light sensors arranged in rows and columns; and determining a touch existence and a position thereof by extracting and analyzing a component of the sensing data signal; wherein the determining of the touch existence and the position thereof further includes: selecting at least a portion of each sensing data signal as an analysis matter: assembling a first matrix of sensed data signals, the matrix of sensed data signals having row elements corresponding to the selected portions of the sensing data signals from respective rows of the light sensors, and column elements corresponding to the selected portions of the sensing data signals from respective columns of the light sensors; determining a second matrix of sensed data signals by, for each row of the first matrix of sensed data signals, determining an average value of the row elements of that row, and subtracting the average value from each row element of that row; determining a covariance matrix from the second matrix; determining eigenvalues of the covariance matrix; selecting highest values of the eigenvalues, and selecting columns of the covariance matrix corresponding to the selected highest values of the eigenvalues; determining the touch existence according to whether values of elements of the selected columns fall within one or more predetermined ranges.