What are the sensors used in mobile phones?

Last Update Time: 2021-02-03 10:37:04

With the advancement of technology, mobile phones are no longer a simple communication tool, but portable electronic devices with comprehensive functions. The virtual functions of mobile phones, such as interaction and games, are realized by the powerful computing power of the processor, but the functions combined with reality are realized by sensors. This article sorts out the common sensors in mobile phones for everyone to help you understand their principles and uses.

1. Light sensor

Principle: Phototransistor, when receiving external light, will produce currents with different strengths, so as to perceive the ambient light brightness.

Uses: Usually used to adjust the brightness of the screen's automatic backlight, increase the brightness of the screen during the day, and reduce the brightness of the screen at night, so that the screen can be seen more clearly, and it is not dazzling. It can also be used for automatic white balance when taking pictures. You can also use the following distance sensor to detect whether the phone is in your pocket to prevent accidental touch.

Second, the distance sensor

Principle: The infrared LED lamp emits infrared rays, and after being reflected by a close-range object, the infrared detector determines the distance by receiving the intensity of infrared rays, and the general effective distance is within 10cm. Distance sensors have both transmitting and receiving devices, and are generally bulky.


Uses: To detect whether the phone is attached to the ear and making a call, so as to automatically turn off the screen to save power. It can also be used to automatically unlock and lock the screen in leather case and pocket mode.

Off-topic: Position of light sensor and distance sensor

The light sensor and the distance sensor are generally placed together and are located around the earpiece of the front of the phone, so there is a problem. There are too many holes in the forehead of the phone or the black strips are not beautiful, so Apple has been trying to reduce the opening , Or hide openings. A black panel phone can easily hide these two sensors, but a white panel is a bit more difficult.

Apple started with the iPhone 5 and made the light sensor white, which is well hidden, but many domestic mobile phone manufacturers can't do it for the time being. They can only choose a smaller size sensor and put the light + distance sensor together A smaller strip, or a large circle as large as the camera, is relatively nice. The hammer's sensor is also long, but it is hidden when placed directly in the earpiece.

3. Gravity sensor

Principle: Using the piezoelectric effect, a weight and a piezoelectric piece inside the sensor are integrated, and the horizontal direction is calculated by the magnitude of the voltage generated in two orthogonal directions.

Uses: intelligent switching of mobile phone horizontal and vertical screens, orientation of taking photos, gravity sensing games (such as rolling steel balls).

Four, acceleration sensor

Principle: The same as the gravity sensor, it is also a piezoelectric effect. The acceleration direction is determined through three dimensions, but the power consumption is smaller, but the accuracy is low.

Uses: step counting, facing angle of mobile phone placement.

5. Magnetic field sensor:

Principle: An anisotropic magnetoresistive material, when a weak magnetic field changes, it will cause its own resistance to change, so the phone needs to rotate or shake a few times to accurately indicate the direction.

Uses: compass, map navigation direction, metal detector APP.

6. Gyroscope:

Principle: Conservation of angular momentum. When an object (gyro) is rotating at high speed, and its rotation axis is not affected by external forces, the orientation of the rotation axis will not change. The gyroscope is based on this principle and uses it to maintain a certain direction. The three-axis gyroscope can replace three single-axis gyroscopes, and can simultaneously measure the position, movement trajectory and acceleration in 6 directions.

There are so many sensors in the phone! Finally got it all

Uses: somatosensory, shake (shake the phone to achieve some functions), pan / turn / mobile phone can control the angle of view in the game, VR virtual reality, when the GPS has no signal (such as in a tunnel) to achieve inertial navigation according to the movement state of the object.

Seven, GPS

Principle: There are 24 GPS satellites in a specific orbit on the earth. Each satellite broadcasts its current location coordinates and time stamp information to the world at all times. The GPS module of the mobile phone receives this information through the antenna. The chip in the GPS module uses the instantaneous position of the high-speed satellite as the known starting data, calculates the distance between the satellite and the mobile phone based on the timestamp of the satellite's transmitting coordinates and the time difference at the time of receiving, and uses the method of spatial distance resection to determine the test The position coordinates of the point.

Uses: map, navigation, speed measurement, distance measurement.


If you want to know more, our website has product specifications for wireless sensors, you can go to ALLICDATA ELECTRONICS LIMITED to get more information