Shared Memory Graphics accuses Apple and Sony of patent infringement

Posted by Aharon Etengoff

San Francisco (CA) - Shared Memory Graphics has accused three industry heavyweights of patent infringement. The California-based company alleges that two patented graphic accelerators are currently used in Apple iPods, Nintendo's Wii and Sony's PSP/PS2.  

One disputed patent - No. 5,712,664 - describes a "shared memory graphics accelerator system." According to the USPTO, performance is enhanced "because display data retrieval from the on-chip frame buffer is much faster than from an external frame buffer...and the DRAM timing constraints are reduced."

The accelerator also allows display memory size to expand by adding external memory to accommodate large displays. In addition,  frame buffer space can be distributed among several integrated solutions, "thereby increasing both the display bandwidth and the parallel processing capability between the CRT display and the CPU."

The above-mentioned patents were originally awarded to Alliance Semiconductor, but were subsequently sold to Shared Memory Graphics. The latter is reportedly demanding unspecified monetary damages, along with an injunction to prevent further infringement.