Although people do not think 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, which, if inhaled in sufficient quantities, and other potentially irritating substances can cause harm to people. Although carbon monoxide detectors and other items exist in the home and in portable form, sometimes the compact version is not small enough to be carried with you. Ideally, adding a gas detector to items that users carry or wear on a daily basis, such as a smartphone or smart watch, would provide a higher level of protection, but current systems cannot be embedded in this way. < / P > < p > the future Apple watch or iPhone may warn users of toxic gases or pollen in their local environment, and apple has come up with a way to reliably sense the air using a combination of lasers and other sensors. In a patent granted by Apple called & quot; particle material sensor for portable electronic devices & quot;, apple proposes a solution to this problem by creating a component that can be installed into the device. Specifically, the patent relates to the accurate detection of particulate matter in the air. < p > < p > in Apple’s air monitoring program, three laser light sources, three total internal reflection lenses, and related optical sensors or photodiodes are proposed to receive optical signals. The light emitted by the laser passes through the lens and reflects to the receiving sensor, which refracts to the sensor itself. Apple says the stack can consist of sensor circuits, at the bottom, superimposed by transmitters and detectors, and then by a lens at the top. This means that the light sensor and the light source will be in the same position, so the light will be bounced back to the origin. By doing so, apple can save design space by eliminating the need to determine the target point of light and placing the detection sensor far away from the transmitter. Apple also recommends VCSELs, which are used in hardware such as the iPhone’s truedepth camera array. < / P > < p > then, the system uses the variation of light power emitted by each light source received by each sensor to determine that the particles have passed before the laser. By detecting the backscattering and reflection of the light beam, the volume of particles in the air can be determined. By using three groups of lasers in different positions, the arrangement can detect the wind speed and the number of particles in three-dimensional space, so as to achieve accurate directional reading. < / P > < p > the system will emit three groups of beams in different directions, adjust the position of the beams as time goes on, and detect the change of induced reflected light at multiple convergence positions. The system can use these data to determine the flow rate and flow direction according to the volume change, which will help to improve the amount of particulate matter measured in a short period of time. The volume of particulate matter is then estimated from the readings and wind speed as well as the concentration of particulates in the gas. < / P > < p > Apple submits a large number of patent applications every week, but although the existence of patent applications indicates areas of interest for Apple’s R & D team, it does not necessarily guarantee that these ideas will appear in future products or services. Didi Qingju bicycle has entered 150 cities