Those unknown sensors on mobile phones | love to play computer games - 上海419贵族宝贝-上海后花园1314-上海品茶网-阿拉爱上海

Today's mobile phones have more and more functions, especially the development of mobile Internet, which makes the progress of mobile phones more rapid. People's requirements for mobile phones are not limited to the past calls and SMS, and we have more and more requirements for mobile phones in terms of functions. In order to achieve different functions, modern mobile phones need to install many sensors. How do these sensors work? This article introduces various sensors on mobile phones and demonstrates the related functions.

The following is the sensor test in the engineering mode of Samsung Galaxy Note II. We will introduce various sensors in the mobile phone in the order shown here.

The following is a demonstration video of the sensor on the mobile phone.

Acceleration sensor (gravity sensing)

Accelerometer is an electronic device that can measure acceleration. In the mobile phone, the acceleration sensor can monitor the magnitude and direction of the acceleration received by the mobile phone. Principle of acceleration sensor: It is realized by piezoelectric effect. A piece of "gravity block" and piezoelectric crystal form a gravity sensing module. When the direction of the mobile phone changes, the force exerted by the gravity block on the piezoelectric crystals in different directions will also change, and the output voltage signal will be different, so as to judge the direction of the mobile phone. Gravity sensing is often used to automatically rotate the screen and some games, but its own limitations are relatively large, because it judges the direction according to gravity, and judges the horizontal direction by sensing the component force of gravity in two orthogonal directions.

Proximity Sensor

Distance sensing is to emit infrared light. When an object approaches, the returned infrared light will be monitored by the element, and then the distance of the object approaching can be judged. Distance sensing is generally used to automatically turn off the screen after a call is connected. Most touch screen phones now have this function. The widely rumored "Big Face Don't Use Touch Screen Phones" on the Internet is obviously unreliable. In addition, some mobile phone films will block the distance sensor, affecting the work, so pay special attention.

In addition, distance sensing can also be applied to some special functions, such as the "quick list" function in Galaxy Note II

Air pressure sensor

The author has had the air pressure sensor before Has. The pressure sensor works through a thin film element that is sensitive to pressure. The thin film is connected with a flexible resistance. When the atmospheric pressure changes, the resistance value will change. The function of air pressure sensor is mainly used to detect atmospheric pressure, current height and auxiliary GPS location.

Light Sensor

The light sensor consists of a projector and a light receiver. The projector focuses the light, transmits it to the light receiver, and finally receives it through the sensor and turns it into an electrical signal. The purpose of light sensing is to adjust the brightness of the mobile phone screen according to the ambient light.

Three-axis gyroscope

About three-axis gyroscope, the author has 。 It is a kind of equipment used to measure angle and maintain direction. Its principle is based on the principle of angular momentum conservation. Let's take a look at the dynamic schematic diagram of the gyroscope. The golden rotor in the middle is our "gyroscope", which will not be affected due to inertial action, while the three "steel rings" around will change due to the change of the equipment's attitude. This is how to detect the current state of the equipment. The axis where these three "rings" are located is the "three axes" in our three-axis gyroscope, namely X axis, Y axis and Z axis. The three-dimensional space enclosed by three axes jointly detects various movements of the mobile phone. The main function of the gyroscope is that it can measure the angular velocity.

Here are some applications of three-axis gyroscopes.

Magnetometer (electronic compass)

The electronic compass uses magnetoresistive sensors to measure the plane geomagnetic field to detect the intensity and direction of the magnetic field. It is similar to our common compass. It is mainly used for electronic compass and GPS positioning.