Update: 2019-08-19 14:51 Source: LUFTMY
When you open WeChat movement, you will see the number of walking steps; In the racing game, you can control the direction of the racing car by shaking your mobile phone.These are all convenience brought by smart phones.What are the main components of a mobile phone that enable these functions? How does it work?
In the era of rapid technological development, various functions of smart phones have been developed, including various sensors installed inside the phones.
The Ambient Light Sensor mainly enables the phone to sense the Ambient Light intensity and adjust the brightness of the phone's screen.The use of light sensors not only makes it convenient for users to automatically adjust the light, but also saves electricity so as to extend the battery life.
Gravity sensor achieves its function through piezoelectric effect.There is a weight and piezoelectric chip in the gravity sensor. The horizontal direction is calculated by the voltage generated in the orthogonal two directions.
The distance sensor emits infrared ray through the infrared LED lamp, which is received by the infrared detector after being reflected by the object. The distance can be judged according to the intensity of receiving infrared ray.Perceive the distance between the phone and the human body to control the switch on the phone screen.
Capacitive fingerprint sensor is a mainstream technology. When the fingerprint sensor works, the finger is one pole of the capacitance and the array of silicon chips is the other.The distance between the peak and trough of human fingerprint and capacitance sensor forms the difference of capacitance, so as to draw the figure of fingerprint.
Accelerometer Sensor uses piezoelectric effect to realize three dimensions to determine the direction of acceleration, which has small power consumption but low accuracy, and its function is to determine the orientation of mobile phone.
The Magnetic Field Sensor works by measuring the electrical resistance of the Magnetic Field to determine the strength of the Magnetic Field for use in compass and map navigation applications.
The Gyroscope is a measurement of the angular velocity of motion along an axis or several axes. Its function is to track and capture the complete movement of 3D space, provide real and accurate navigation system, VR technology and other functions.
GPS calculates the direct distance between the mobile phone and the satellite through the time difference between the time stamp of the launching coordinate of the GPS satellite and the time difference of the receiving coordinate.It is used for positioning, speed measurement, distance measurement and navigation.
The intensity of ultraviolet light can be calculated by examining the photoelectric emission effect of metal compounds or certain semiconductors, which releases large amounts of electrons under ultraviolet light.
Barometer sensor is composed of the film and rheostat or capacitance. When the air pressure changes, the resistance or capacitance value will change and the air pressure data will be obtained.
The heart rate sensor irradiates the finger with a high-brightness LED light, and captures the periodic changes of blood to the capillaries, so as to obtain the contraction frequency and heartbeat data of the heart.
By irradiating the finger with infrared light and red light LED at the same time, the absorption rate of hemoglobin and oxyhemoglobin in blood to red light is displayed, and the absorption spectrum of reflected light is measured, so as to measure the oxygen content of blood.
Mainly based on the hall magnetoelectric effect, when the current passes through the conductor located in the magnetic field, the magnetic field will exert a force on the electrons in the conductor perpendicular to the direction of motion of the electrons, thus generating potential difference between the two ends of the conductor.It is mainly used for clamshell unlock and clamshell lock screen function.