On March 2, 2020, the US International Trade Commission (ITC) issued a decision finding that DJI, the world’s largest consumer drone company, infringed US Patent No. 9,260,184 owned by Autel Robotics. The judge’s initial determination recommended a cease and desist order banning DJI from importing into the US its most popular drones–Mavic Pro, Mavic Pro Platinum, Mavic 2 Pro, Mavic 2 Zoom, Mavic Air, and Spark. The news of this decision spread like wildfire through the drone-enthusiast community. Was this the end of DJI drones in the US? Not quite. Autel’s victory was short-lived. Last week, DJI invalidated Autel’s drone patent.

What exactly does the ‘184 Patent cover?

In general, a patent protects a single innovative feature–not the entire system. A complex device, such as an unmanned aircraft, could involve hundreds–or even thousands–patented components. In this case, the ‘184 Patents claims the lock mechanism for securing a removable blade onto a driveshaft of a motor. Drone pilots know too well that drone blades are fragile, and even a small accident can shatter the blade. Hence, most drones have removable and replaceable blades.

A drone has two sets of blades–a first pair for clockwise rotation and a second pair for counterclockwise rotation. Visually, however, all blades appear nearly indistinguishable. An inexperienced pilot could easily make a mistake of mounting a wrong blade onto a wrong driveshaft. Launching a drone with incorrectly mounted blades would be disastrous. This is where the ‘184 Patent comes in.

The ‘184 Patents claims a drone, in which “the clockwise rotor blade is engageable only with the clockwise lock mechanism and cannot be engaged in the counterclockwise lock mechanism, and the counterclockwise rotor blade is engageable only with the counterclockwise lock mechanism and cannot be engaged in the clockwise lock mechanism.” DJI implemented this fool-proof locking mechanism on its popular Mavic drones, so Autel sued.

Annotated drawings from the ‘184 Patents.

Victory short-lived

An effective patent infringement defense strategy is to immediately challenge validity of the asserted patent claims. One of the most effective and efficient ways of invalidating a patent is through an Inter Partes Review (IPR), which is an administrative trial before the USPTO. DJI lawsuit is a case-in-point.

Autel filed its ITC complaint against DJI on September 26, 2018. Less than two months later, on November 16, 2018, DJI responded with an IPR Petition challenging validity of Autel’s patent claims for lack of novelty and obviousness. On May 20, 2020, just two months after Autel’s highly-publicized ITC win, the USPTO resolved the IPR in favor of DJI, invalidating Autel’s key patent claims. Because an invalid patent cannot be infringed, DJI is off the hook. After two turbulent months, the US drone market is back to status quo. Thanks to its clutch IPR win, DJI can continue its reign as the king of consumer drones.