Although people do not think about it all the time, air is an important element in life, but it is also a potential danger. There may be invisible problems in the air, such as pollen or toxic gases. If inhaled in sufficient quantities, it and other potentially irritating substances can cause harm to people. Although items such as carbon monoxide detectors exist in homes and are in portable form, sometimes the compact version is not small enough to be easily carried around. Ideally, adding a gas detector to items that users carry or wear daily (such as smartphones or smart watches) will provide a higher level of protection, but current systems cannot be embedded in this way.
The future Apple Watch or iPhone may warn users of toxic gases or pollen in the local environment. Apple has come up with a method to reliably sense the air using a combination of lasers and other sensors. In a patent entitled “Particulate Matter Sensor for Portable Electronic Devices” obtained by Apple, Apple proposed a solution to such a problem by creating a component that can be installed in the device. Specifically, the patent relates to accurate detection of particulate matter in the air.
In Apple’s air monitoring program, it is proposed to use three laser light sources, three total internal reflection lenses, and related light sensors or photodiodes to receive light signals. The light emitted by the laser passes through the lens and is reflected to the receiving sensor, and the light is refracted to the sensor itself. Apple said that the stack can be composed of sensor circuits, on the bottom layer, superimposed by the emitter and detector, and then a lens on the top. This will mean that the light sensor and the light source will be in the same position, so the light will be bounced back to the origin. This allows Apple to eliminate the need to determine the target point of the light, and place the detection sensor far away from the transmitter, saving design space. Apple also recommends using VCSELs, which are used in hardware such as the iPhone’s TrueDepth camera array.
Then, the system uses the change in the light power emitted by each light source received by each sensor to determine that the particles have passed the laser. By detecting the backscatter and reflection of the light beam, it can be used to determine the volume of particles in the air. By using three sets of lasers in different positions, this arrangement can detect wind speed and the number of particles in three-dimensional space, thereby achieving accurate directionality reading.
The system will emit three sets of beams in different directions, adjust the beam position over time, and detect changes in the induced reflected light at multiple converging positions. The system can use these data to determine the flow rate and direction according to the volume change, which will help increase the number of particles it can measure in a short time. Then estimate the volume of particulate matter based on the readings and wind speed and the concentration of particulate matter in the gas.
Apple submits a large number of patent applications every week, but although the existence of patent applications indicates areas of interest to the Apple R&D team, it does not necessarily guarantee that these ideas will appear in future products or services.