A light sensor is a sensor that converts light signals into electrical signals using photosensitive elements. The light sensor is usually composed of a set of light projector and light receiver. Light sensors are generally composed of three parts: light source, optical path and optoelectronic components. The measured changes are converted into changes in optical signals are further converted into electrical signals with the help of photoelectric elements. In the future, with the development and popularization of Internet of Things technology, the application of light sensors will penetrate into all aspects of human life.
What is A Light Sensor?
A light sensor is a sensor that converts light signals into electrical signals using photosensitive elements. The light sensor is usually composed of a set of light projector and light receiver. The light projector focuses the light through the lens, transmits it to the lens of the light receiver, and then transmits it to the receiving sensor. The sensor converts the received optical signal into an electrical signal, and the electrical signal can further perform various switching and control actions. In other words, the basic principle of the light sensor is to use the signal obtained by the light change between the light projector and the light receiver to complete various automatic controls. Light sensors can be divided into the following forms:
Principle: Separate the emitter and the receiver at both ends, and if the light between the two is disturbed by an object, the state of the switch will be changed.
Advantages: Long detection distance, and can detect difficult objects, such as shiny surface objects.
Disadvantages: Complicated installation, wiring and calibration
Principle: The light emitter and the light receiver are installed in the same lens, the light is emitted from the light emitter end, and is reflected back to the receiver end by a reflector.
Advantages: Easy installation and wiring, simple and flexible in calibration
Disadvantages: The detection distance is small, and the light will also weaken its energy after multiple reflections between the lens and the reflector.
Principle: The light emitter and the light receiver are installed in the same lens, but the light emitted by the light emitter is reflected by the surface of the object and then returned to the light receiver.
Advantages: Inexpensive, easy to install and calibrate.
Disadvantage: The detection function may be affected by the reflection on the surface of the object.
Principle: Use the optical fiber cable to guide the emitter and receiver in the same lens to the required place.
Advantages: Safe, can be used in places with high temperature, vibration, protrusions.
Disadvantages: The material may deteriorate due to environmental factors.
Future Development Trends
Light sensors are generally composed of three parts: light source, optical path and optoelectronic components. The measured changes are converted into changes in optical signals, and then the optical signals are further converted into electrical signals with the help of photoelectric elements.
The four major areas of sensor applications are industrial and automotive electronic products, communication electronic products, and special devices for consumer electronic products, of which the sensor market in the field of industrial and automotive electronic products accounts for about 42%. In the future, with the development and popularization of Internet of Things technology, the application of light sensors will penetrate into all aspects of human life. The future development direction of light sensors will be as follows:
Due to the increasingly tight design space, cost and power consumption budget, integrating multiple sensitive components on the same substrate to make a multifunctional combined MEMS sensor capable of detecting multiple parameters has become an important solution.
Low Power Consumption
The demand for reducing the power consumption of the sensor, using ambient energy harvesting to achieve self-supply, and enhancing the battery life will accompany the development of the sensor, and it will become more and more intense.
The miniaturization of the sensor means that the characteristic size of the sensitive element is "millimeter (mm) - micrometer (um) - nanometer (nm)" type of sensor. This type of sensor has the advantages of miniaturization in size and performance, integration in elements and diversity in use, systematicness in function and composite in structure. The miniaturization of the sensor is by no means the miniaturization or reduction of the feature size, but a high-tech microsystem with new mechanism, new structure, new function and new function. Its preparation process involves MEMS technology, 1C technology, laser technology, precision ultra-fine processing technology, etc.
Technological developments show that digital signal processors (DSPs) will drive the development of many new next-generation sensor products. With the development of 5G communication, big data, AR, VR, cloud computing, etc., as well as the application of new technologies such as robot internal driving and artificial intelligence, the world has entered the era of intelligence from the original era of electricity, and sensors have also ushered in a new era. The new era of intelligence.
Photoelectric sensor When a person or object enters the sensing range in front of the sensor (reflection point, small angle), the sensor will output immediately, and the output of the sensor will be turned off immediately after the person or object leaves. For example, in smart lighting, the lights can be turned on when people come, and the lights can be turned off when people leave, thus effectively ensuring the quietness of the living space in the building.
Regarding the current situation and future development trends of sensors, sensors, as the heart of the Internet of Things, have a huge space for development. At present, sensors are in an important development stage of industrial structure upgrading. With the obvious trend of smart modernization such as medical treatment, artificial intelligence, Internet of Things, and smart cities in the future, MEMS sensors have great potential for development in the future.