Amazon Dodges Search Autocomplete Patent Suit

In a Thursday opinion, a Northern District of California judge granted Amazon’s motion for summary judgment of noninfringement in a patent case concerning Amazon’s product search automcompletion technology.

MasterObjects Inc., filed its complaint against Inc., alleging the defendant’s autocomplete technology for digital searches infringed on three of the plaintiff’s patents. According to the opinion, the two parties have litigation history: MasterObjects has filed multiple patent infringement lawsuits against Amazon since 2011.

The opinion states, “Of principal concern here, the key limitation in the claim recited above is directed to the system’s use of a “cache” to provide autocomplete results… All the other claims – in – suit similarly reference a cache as well as a “data source” (or “content sources”) … The lay reader will likely have a general awareness of a cache in the computing sense, such as a web browser (e.g., Mozilla Firefox) storing an iteration of a previously visited webpage (e.g.,  This order addresses the use of the term “cache” by the patents-in-suit.”

The judge summarized what they described as MasterObjects’ “best” argument: “even though the autocomplete query is not stored in a ‘cache,’ the accused system generates a sequence of prefixes — one of which by definition must correspond exactly to the query — and stores them in a ‘cache.'”

But, the judge says, the argument fails as Amazon’s autocomplete keyword database is built from prior product searches, not from autocomplete results like the claimed systems.

The opinion concludes that Amazon’s system does not practice the claimed cache-and-data-source structure as claimed in MasterObject’s lawsuit; thus, there is no patent infringement.

Amazon is represented by Hueston Hennigan. MasterObject is represented by Hosie Rice, Heim, Payne & Chorush, and Zuber Lawler.