[
Pacific Security Network News ]
Do you know what is the core part of the webcam? Everyone knows that the reputation of network cameras has become popular all over the world. It is powerful and easy to use, which provides a guarantee for people's safety. So what is the core of the network camera? Let me introduce you to the following.
The network camera can be directly connected to the digital network of TCP/IP, so the main function of this system is to transmit video and audio over the Internet or through the internal LAN. From the internal structure, the basic structure of the network camera is generally composed of image sensors, video encoders, network servers, external alarms, control interfaces and other parts.
Compared with traditional analog cameras, the core technology of network cameras is video encoders. Now, let's do a technical analysis on each part of the network camera, and then focus on the core video encoder part.
Image Sensor
The traditional analog camera collects video information through an image sensor, and then directly outputs an analog video signal, which is externally output through the video line. There are two main types of image sensors for cameras, namely CMOS and CCD. Since CCD has certain advantages over CMOS in image quality, the image sensor used in monitoring engineering is mainly CCD, and most of the mainstream manufacturers of CCD are Japanese companies, such as Sony and Sharp, which account for almost all of the global CCD market. More than 90% share.
Video encoder
Its function is to digitally encode the video signal of CCD according to a certain format, and some of them directly capture the BT of the CCD output. Some of the signals of the 656 are analog signals that are acquired by the CCD drive output, and are analog-digital converted by a video AD. There are many standards for video coding, and now the main standards for network cameras are MJPEG, MPEG4 and H. 264.
Network Server
Its function is to output the compressed video signal through the TCP/IP protocol, and basically support the current mainstream communication formats, such as support for PPPOE, DNS, UDP, TCP, and so on.
External alarm and control interface
External Alarms and Controls The reputation of network cameras has become popular all over the world. It is powerful and easy to use, providing a guarantee for people's safety. So what is the core of the network camera? Let me introduce you to the following.
The network camera can be directly connected to the digital network of TCP/IP, so the main function of this system is to transmit video and audio over the Internet or through the internal LAN. From the internal structure, the basic structure of the network camera is generally composed of image sensors, video encoders, network servers, external alarms, control interfaces and other parts.
Compared with traditional analog cameras, the core technology of network cameras is video encoders. Now, let's do a technical analysis on each part of the network camera, and then focus on the core video encoder part.
Image Sensor
The traditional analog camera collects video information through an image sensor, and then directly outputs an analog video signal, which is externally output through the video line. There are two main types of image sensors for cameras, namely CMOS and CCD. Since CCD has certain advantages over CMOS in image quality, the image sensor used in monitoring engineering is mainly CCD, and most of the mainstream manufacturers of CCD are Japanese companies, such as Sony and Sharp, which account for almost all of the global CCD market. More than 90% share.
Video encoder
Its function is to digitally encode the video signal of CCD according to a certain format, and some of them directly capture the BT of the CCD output. Some of the signals of the 656 are analog signals that are acquired by the CCD drive output, and are analog-digital converted by a video AD. There are many standards for video coding, and now the main standards for network cameras are MJPEG, MPEG4 and H. 264.
Network Server
Its function is to output the compressed video signal through the TCP/IP protocol, and basically support the current mainstream communication formats, such as support for PPPOE, DNS, UDP, TCP, and so on.
External alarm and control interface
The external alarm and control interface are the auxiliary functions of the network camera, mainly through the serial port or 10 ports. The serial port mode includes RS232 and RS485. The interfaces are auxiliary functions of the network camera, mainly through the serial port or 10 ports. The serial port modes include RS232 and RS485.
Resistive Touch Screen
The outermost layer of resistance screens is usually a soft screen that connects the internal contacts up and down by pressing. The inner layer contains the oxidized metal of the physical material, namely N-type oxide semiconductor (indium oxide), also known as indium oxide, with an optical transmittance of 80% and the upper and lower layers separated by the middle. ITO is the main material used in both resistive and capacitive touch screens. Their working surface is the ITO coating. The outer layer is pressed by fingertips or any object to make the surface film concave and deformed. According to the leading line number of screen, divide again have 4 line, 5 line and much line, threshold is low, cost is opposite cheap, advantage is not affected by dust, temperature, humidity. Disadvantages are also obvious, the outer screen film is easy to scratch, can not use sharp objects to touch the surface. In general, multi-touch control is not allowed, that is, it can only support a single point. If two or more contacts are pressed at the same time, they cannot be recognized and accurate coordinates can be found. To enlarge a picture on the resistance screen, you can only click "+" several times to make the picture be enlarged step by step. This is the basic technical principle of the resistance screen.
Control by pressure induction. When a finger touches the screen, the two conductive layers are in contact at the touch point and the resistance changes. A signal is generated in both X and Y directions and transmitted to the Touch Screen controller. The controller detects the contact and calculates the position of (X, Y), then works according to the simulated mouse mode. Resistive Touch screen is not afraid of dust, water and dirt, and can work in harsh environments. But because the outer layer of the composite film is made of plastic material, its anti-explosion property is poor, and its service life is affected to some extent.
The resistive touch screen is controlled by pressure induction. The surface layer is a layer of plastic and the bottom layer is a layer of glass, which can withstand the interference of harsh environmental factors. However, it has poor hand feel and light transmittance, so it is suitable for wearing gloves and occasions that cannot be touched directly by hand.
Resistive Touch Screen
Resistive Touchscreen,Resistive Screen,Resistive Touch,Resistive Touch Panel
Tonya Display Limited , https://www.tydisplay.com