Thales Visionix Inc. appealed from a Claims Court judgment that most claims of its U.S. Patent No. 6,474,159 were directed to patent-ineligible subject matter.
The patent discloses an inertial tracking system for tracking the motion of an object relative to a moving reference frame. Inertial sensors, such as accelerometers and gyroscopes, measure the specific forces associated with changes in a sensor’s position and orientation relative to a known starting position. Such sensors are used in a wide variety of applications, including aircraft navigation and virtual reality simulations. When mounted on a moving object, inertial sensors can calculate the position, orientation, and velocity of the object in 3-dimensional space, based on a specified starting point, without the need for any other external information. Because small errors in the measurement of acceleration and angular velocity translate to large errors in position over time, inertial systems generally include at least one other type of sensor, such as an optical or magnetic sensor, to intermittently correct these errors that compound over time.
The patent disclosure recognized that conventional solutions for tracking inertial motion of an object on a moving platform were flawed because both object and platform-based inertial sensors measured motion relative to earth, and the error-correcting sensors on the tracked object measured position relative to the moving platform. Attempting to fuse this data produced inconsistent position information when the moving platform accelerated or turned.
The inertial sensors disclosed in the patent do not use the conventional approach of measuring inertial changes with respect to the earth. Instead, the platform (e.g., vehicle) inertial sensors directly measure the gravitational field in the platform frame. Object (e.g., helmet) inertial sensors then calculate position information relative to the frame of the moving platform. By changing the reference frame, one can track the position and orientation of the object within the moving platform without input from a vehicle attitude reference system or calculating orientation or position of the moving platform itself.
Claims 1 and 22, the only independent claims, recite:
1. A system for tracking the motion of an object
relative to a moving reference frame, comprising:
a first inertial sensor mounted on the tracked object;
a second inertial sensor mounted on the moving reference frame; and
an element adapted to receive signals from said first and second inertial sensors and configured to determine an orientation of the object relative to the moving reference frame based on the signals received from the first and second inertial sensors.
22. A method comprising determining an orientation of an object relative to a moving reference frame based on signals from two inertial sensors mounted respectively on the object and on the moving reference frame.
The alleged infringing products were helmet mounted display systems (HMDS) in F-35 Joint Strike Fighters. Thales Visionix sued the government and Elbit Systems of America, the government subcontractor that produced the helmets, jointed the case.
The Federal Circuit began its analysis at Alice step one: “whether the claims at issue are directed to a patent-ineligible concept.” While the two steps of the Alice framework are related, the Supreme Court’s formulation makes clear that the first-stage filter is a meaningful one, sometimes ending the § 101 inquiry.
The Federal Circuit noted, citing to Enfish, that the Supreme Court has not established a definitive rule to determine what constitutes an ‘abstract idea’” for the purposes of step one. The Federal Circuit has held claims ineligible as directed to an abstract idea when they merely collect electronic information, display information, or embody mental processes that could be performed by humans. At the same time, according to Alice, “all inventions at some level embody, use, reflect, rest upon, or apply laws of nature, natural phenomena, or abstract ideas.” The Federal Circuit must therefore ensure at step one that they articulate what the claims are directed to with enough specificity to ensure the step one inquiry is meaningful.
The Federal Circuit compared the claims in this case to the claims in Diamond v. Diehr . In Diamond v. Diehr, the Supreme Court confirmed the eligibility of patent claims despite the inclusion of a mathematical formula in a claimed method for molding raw, uncured rubber into cured rubber products. The claimed method used the well known Arrhenius equation to calculate the optimal cure time using, among other variables, the internal temperature of the mold. The invention in Diamond v. Diehr improved upon prior art molding methods by constantly measuring the actual temperature inside the mold, recalculating the ideal cure time, and automatically opening the press when the ideal cure time equaled the actual time elapsed.
The Supreme Court recognized that a mathematical formula like the Arrhenius equation is not itself patent-eligible subject matter, even if limited to a particular technological environment or accompanied by insignificant post-solution activity. Nonetheless, the Supreme Court held that the claims in Diehr covered patent-eligible subject matter because they described a process of curing rubber beginning with the loading of the mold and ending with the opening of the press and the production of a synthetic rubber product that has been perfectly cured—a result previously unknown in the art. It explained that claims are patent eligible under § 101 “when a claim containing a mathematical formula implements or applies that formula in a structure or process which, when considered as a whole, is performing a function which the patent laws were designed to protect.” In terms of the modern day Alice test, the Diehr claims were directed to an improvement in the rubber curing process, not a mathematical formula.
The Federal Circuit stated that, for the purpose of evaluating patent eligibility, the ’159 patent claims are nearly indistinguishable from the claims in Diehr.
While the claims utilize mathematical equations to determine the orientation of the object relative to the moving reference frame, the equations—dictated by the placement of the inertial sensors and application of laws of physicsserve only to tabulate the position and orientation information in this configuration. This arrangement is analogous to the claims in Diehr.
Just as the claims in Diehr reduced the likelihood that the rubber molding process would result in “overcuring” or “undercuring,” the claims here result in a system that reduces errors in an inertial system that tracks an object on a moving platform.
The ’159 patent claims provide a method that eliminates many “complications” inherent in previous solutions for determining position and orientation of an object on a moving platform. Because the motion of a moving platform like a plane is more dynamic and unpredictable than the earth’s rotation, a traditional system (which measured inertial data with respect to the earth) had difficulty accurately calculating inertial data of an object on a moving platform.
Though the unconventional utilization of inertial sensors as specified by the ’159 patent “may seem somewhat strange” to those within the field, this combination of sensor placement and calculation based on a different reference frame mitigates errors by eliminating inertial calculations with respect to the earth. The resulting system works with any type of moving platform and is simpler to install than conventional systems. The system is also beneficially self-contained: it requires no external information about the orientation or position of the platform.
The Federal Circuit held that the patent claims at issue are not directed to an abstract idea. The claims specify a particular configuration of inertial sensors and a particular method of using the raw data from the sensors in order to more accurately calculate the position and orientation of an object on a moving platform. The mathematical equations are a consequence of the arrangement of the sensors and the unconventional choice of reference frame in order to calculate position and orientation. Far from claiming the equations themselves, the claims seek to protect only the application of physics to the unconventional configuration of sensors as disclosed. As such, the claims are not directed to an abstract idea and thus the claims survive Alice step one.
Because the claims are not directed to an abstract idea, the Federal Circuit did not proceed to step two.
It is possible that the fact that the patent drafter’s indication that the arrangement of the sensors “may seem somewhat strange” helped sway the court.