US 7,499,044 B2
System for synchronizing display of images in a multi-display computer system
Joseph P Kennedy, Palo Alto, Calif. (US); John A Klenoski, Fremont, Calif. (US); and Greg Sadowski, Cambridge, Mass. (US)
Assigned to Silicon Graphics, Inc., Sunnyvale, Calif. (US)
Filed on Oct. 30, 2003, as Appl. No. 10/695,779.
Prior Publication US 2005/0093854 A1, May 05, 2005
Int. Cl. G09G 5/00 (2006.01)
U.S. Cl. 345—213  [345/1.1; 327/39; 327/47] 23 Claims
OG exemplary drawing
 
1. An image display system for synchronizing the display of images on a plurality of display devices, comprising:
a first computer system generating a first signal representing first image data to be displayed on a first display device;
a second computer system generating a second signal representing second image data to be displayed on a second display device; and
means for synchronizing said first and second image data, said synchronizing means comprising:
a master sync signal generated from a master sync signal generator; and
a signal generating means for receiving the master sync signal and generating a video clock signal from the master sync signal wherein the video clock signal is synchronized with the master sync signal;
a comparison means for determining if the video clock signal is no longer synchronized with the master sync signal;
wherein in response to the comparison means determining that the video clock signal is no longer synchronized with the master sync signal, the signal generating means reestablishes the synchronization between the video clock signal and the master sync signal; and
wherein the reestablishment of the synchronization between the video clock signal and the master sync signal occurs over a convergence time, wherein the duration of the convergence time is programmable, said duration of the convergence time beginning at the start of convergence and ending at the achievement of convergence.