James R Mcgrath

US Patent:

20010043172, Nov 22, 2001

Filed:

Mar 22, 2001

Appl. No.:

09/814545

Inventors:

James McGrath - South Yarmouth MA, US
Alan Palevsky - Wayland MA, US
Clifford Johnson - Lunenburg MA, US
Gregory Gott - Rockland MA, US
Helmut Lelke - Southborough MA, US

International Classification:

G09G003/22

US Classification:

345/075200

Abstract:

A method for forming images on a display having a matrix of rows and columns of pixels is provided. Such method comprises the steps of: successively addressing the rows of pixels, each one of the rows of pixels being addressed for a predetermined addressing period of time. During each predetermined addressing period of time, a voltage level is applied to each one of the columns of pixels for a time duration in accordance with image intensity data and changing to a different voltage level during the remaining period of the addressing period of time. The voltage level changes only once during each predetermined addressing period of time. The anode of the display is coupled to a power supply adapted to couple either a relatively high voltage to the anode when such display is to operate in a relatively bright environment or a relatively low voltage when such display is to operate with relatively dim environment. The images are characterized by a gray scale level at each one of the pixels. The gray scale level is modified by a contrast term.