On September 12th, the U.S. Patent and Trademark Office issued a final office action in an ex parte reexamination of a patent owned by Google self-driving car development subsidiary Waymo. As a result of the reexamination, Waymo stands to lose 53 of 56 claims, including all 20 of the patent claims originally issued. The patent in question had been asserted as part of the company’s well-known infringement suit filed against Uber.

The patent at the center of this reexamination is U.S. Patent No. 9368936, titled Laser Diode Firing System. Issued to Google in June 2016, it claims an apparatus including a voltage source, an inductor coupled to the voltage source and configured to store energy in a magnetic field, a diode coupled to the voltage source via the conductor, a transistor that can be turned on or off by a control signal, a light emitting element coupled to the transistor and a capacitor coupled to charging and discharge paths where the charging path includes the inductor and the diode and the discharge path includes the transistor and the light emitting element. The invention provides a laser diode firing circuit for a light detection and ranging (LIDAR) device where the emission and charging operations of the firing circuit can be controlled by operation of a single transistor.

The reexamination of the ‘936 patent was requested in August 2017 by an engineer named Eric Swildens who, according to news reports, has no connection to either Uber or Waymo but became interested in the potential invalidity of the patent after it was asserted in Waymo’s case against Uber. The reexam requested by Swildens has to date been able to knock out all 20 claims of the claims originally issued in the patent, with only three amended claims that were added to the patent during the reexam proceeding being found to be patentable by the reexamination examiner.

34 of the claims challenged in the reexamination were invalidated under 35 U.S.C. § 102(a) grounds as anticipated by U.S. Patent No. 7969558, titled High Definition LIDAR System (“Hall”). The USPTO determined that diagrams attached to the Hall patent disclosed various elements of Waymo’s ‘936 patent including all the limitations of claim 1. Various other elements including the charging of the capacitor following emission of a pulse of light and a method of turning off a transistor for charging a capacitor via the charging path. Another four claims of the ‘936 patent were invalidated on 35 U.S.C. § 103 grounds for obviousness over Hall in view of an IEEE paper published in 2010 which taught the use of gallium nitride field effect transistors (GaNFET), thus providing the limitation necessary to knock out those additional claims.

The reexamination left intact claims 32, 44 and 56 of the ‘936 patent. Although every feature of claims 1, 9 and 17, to which the intact claims were dependent, were disclosed by Hall and U.S. Patent No. 5895984, titled Circuit Arrangement for Feeding a Pulse Output Stage (“Renz”), the cited prior art didn’t disclose or teach coupling a second terminal of the capacitor to a reference voltage other than ground voltage. Although Waymo had argued that the diagrams from Hall do not invalidate other claims because light emitting elements and transistors are not in “the discharge current path,” the USPTO found this argument lacking in light of the patent owner’s previous interpretation of the claim limitation “discharge path.” “It does not make sense that Patent Owner is on one hand trying to state the interpretation of discharge path is so well known and clear but on the other hand is not even using this phrase to differentiate the prior art by using another phrase,” the office action reads.

While some media will no doubt report that Waymo has lost these claims once and for all, a final office action is not as final as it otherwise may sound. If Google wishes to continue to fight there will be other procedural steps that can be taken, including an appeal of this final office action to the Patent Trial and Appeal Board, and ultimately an appeal outside the USPTO to the United States Court of Appeals for the Federal Circuit. Stay tuned.