Apple Reveals their new Magnetometer Architecture that will advance Compass and Mapping Apps & Future Gaming
Apple first introduced a Compass app for the iPhone 3GS in 2009. A new patent application filed by Apple and published by the US Patent & Trademark Office yesterday, reveals a new magnetometer architectural upgrade for their compass app and beyond to include mapping apps and gaming in a multitude of ways.
According to Apple's patent application "in a digital compass application executed on a smartphone, the raw magnetometer output data is provided to processor(s) through a peripheral interface (#503 of patent FIG. 5 below). Processor(s) execute sensor-processing instructions to perform further processing (e.g., averaging, formatting, scaling) of the raw magnetometer output data. Processor(s) execute instructions for various applications running on the smartphone.
For example, Apple notes that "a digital compass uses the magnetometer data to derive heading information to be used by a compass or navigation application. The more accurate the magnetometer data the more accurate the heading calculation for the electronic device. Other applications are also possible (e.g., navigation applications, gaming applications, calibrating other sensors)." Navigation apps noted in the plural could mean that it also applies to Apple's future indoor mapping app.
For games, the PlayStation has used magnetometers to assist in position tracking and orientation. In a 2019 publication they note that magnetometers could be used in relation to VR gaming and controllers that a user will use. Technically that could translate to include future accessories like Apple's proposed finger devices and/or gaming gloves (01, 02, 03).
Apple's patent application states that one or more of the advantages of the new architecture includes the optimization of the performance of a magnetometer, which in turn, improves the accuracy of magnetometer readings used by a digital compass and other applications running on a mobile device that require mobile device orientation data.
In a first embodiment, the integration of reset coils in the magnetic yoke provides a low hysteresis magnetometer architecture that allows the magnetic yoke and the magnetic field sensor to be reset simultaneously to a uniform magnetic state after, for example, exposure to a stray magnetic field. The integrated architecture also allows a reduced foot print in the sense layer.
In a second embodiment, reset coils are wound around magnetic pole pieces offset from the magnetic yoke that allows the magnetic field sensor to be reset to a uniform magnetic state.
Apple's patent FIG. 1 below FIG. 1 is a conceptual diagram that illustrates the use of a magnetic yoke to divert flux to an in-plane magnetic field sensor of a magnetometer; FIG. 2 is a conceptual diagram of a magnetometer architecture that includes a magnetic yoke with integrated reset coils.
Apple's patent FIG. 3 above is a conceptual diagram of a magnetometer architecture that includes a magnetic yoke and reset coils wound on magnetic pole pieces offset from the magnetic yoke; FIG. 5 is a block diagram of an electronic device architecture that includes at least one of the magnetometer architectures described FIGS. 2 and 3.
Apple's patent application number 20200319265 that was published today by the U.S. Patent Office was filed back in Q2 2019. Considering that this is a patent application, the timing of such a product to market is unknown at this time.
Many Apple patents covering a future HMD include motion sensors with specific mention of a magnetometer. Smart health workout gloves were highlighted in a 2016 patent that covered motion sensors including a magnetometer.
The Oculus VR sensor includes a gyroscope, accelerometer, and magnetometer. When the data from these devices is fused, Oculus engineers have stated that "we can determine the orientation of the player’s head in the real world and synchronize the player’s virtual perspective in real-time. Their magnetometer measures strength and direction of the magnetic field."