Transforms optical image signals into electrical signals for storage or transmission. When we take a picture of an object, the light reflected from the object is collected by the lens of the camera, which focuses on the lighted surface of the camera device (e.g., the target surface of the camera tube), and then converts the light into electrical energy through the camera device, i.e., obtaining a "video signal".
The photoelectric signal is very weak, need to be amplified through the pre-discharge circuit, and then through a variety of circuits for processing and adjustment, and finally get the standard signal can be sent to the VCR and other recording media on the record, or through the dissemination of the system spread or sent to the monitor on the display.
Expanded Information
Surveillance cameras and ordinary cameras difference
1, the field of application
Ordinary cameras are mainly used to meet the daily needs of the network, such as video chatting, taking pictures, etc.; surveillance cameras are mainly used for security checks, real-time monitoring, etc.
2, manipulation
Surveillance cameras use remote wireless control, ordinary cameras are not.
3, image quality
Most of the surveillance cameras have anti-glare, anti-vibration and other features, high resolution imaging, clear and bright picture, good night vision, the background can be added to a variety of software. Ordinary cameras, on the other hand, have a fixed shooting angle, poor lens light transmission, fuzzy imaging, can not be photographed from a distance photography, does not have the ability to sense infrared light, night imaging quality is poor.
Baidu Encyclopedia - Camera