Definition and standards of high-definition digital TV and certification of related products

Definition and standards of high-definition digital TV and certification of related products

1. Definition of high-definition digital TV and high-definition digital TV receiver (integrated) machine DTV (Digital TV) is a complex system, that is, the entire broadcast link from the collection of TV signals, the shooting of programs, editing and production, transmission, reception, etc. All systems using digital technology. Therefore, it is a system-level concept, which is the same as the provisions of the industry standard issued by the Ministry of Information Industry in China.
High-definition digital TV is one of the most advanced digital TV DTV standards, referred to as HDTV; its widescreen mode is 16: 9, and uses multi-channel transmission. It is also a comprehensive concept, involving a large number of technical indicators such as sharpness, brightness, contrast, color gamut coverage, and the requirements of supported image formats, interfaces, etc., but of course the most essential is the sharpness index. In the general specification standard "High-definition TV Digital Video Signal Interface" released by China, the image resolution of the HD display is required to be 1920x1080i / 50Hz (1080 is the TV line, which means that the human eye can observe the details of the TV image. Clarity), about twice that of conventional TV, and equipped with multi-channel surround sound.
Therefore, the authoritative organization "National Digital TV Reception Equipment and Performance Standards Development Working Group" defines HDTV high-definition digital TV as follows: it can receive terrestrial reception standards (later expanded to satellite and cable reception standards, etc.) radio frequency, vertical resolution is not less than 720 TV line, the national format is 1920 × 1080i, the aspect ratio is 16: 9, and it is backward compatible with 4: 2: 2 and 4: 2: 0 standard definition digital TV devices. It can be divided into an all-in-one machine and a split machine; an all-in-one machine refers to a high-definition digital TV receiver with built-in full-function high-definition digital receiver set-top boxes (source decoding, channel decoding, conditional access, digital signal processing and display, etc.), which directly Marked as HDTV receiver, but there is no such high-definition digital TV receiver (integrated) machine in the real sense in our country; the split machine refers to the high-definition digital TV monitor (Monitor) without various types of high-definition digital receiver set-top boxes. It is identified by HDTVready, which means that it can receive and correctly display HDTV images decoded by an external HD digital receiver set-top box. Therefore, the so-called high-definition televisions on the market are actually HDTV ready high-definition digital television monitors (Monitor).

2. HDTV high-definition digital TV display standard
In addition to channel coding and signal transmission technology, HDTV standards have about 18 display formats to choose from. Among them, 1080i and 720P are both internationally recognized digital high-definition television standards. Because the original NTSC countries use the 1080i / 60Hz format, which is the same as the NTSC analog TV field frequency. In Europe and China, some original PAL countries have adopted 1080i / 50Hz mode, and the field frequency is the same as PAL analog TV. Among them, 1080 and 720 represent the resolution that can be achieved in the vertical direction; i represents interlaced scanning, and P represents progressive scanning. Interlace is like a blind, which is an incomplete image. Progressive displays a complete picture at a time (as shown below); progressive scan includes 1080 / 24P / 25P / 30P, interlaced scan 1080 / 50i / 60i, etc. However, don't simply think that 1080i must be better than 720P. Although 1080i can provide higher pixels (2.07 million), which is much higher than 720P's 920,000, but the stability of the screen is 720P. High-definition standard GY / T 155-2000 including six types of digital TV monitors including liquid crystal LCD, plasma PDP, liquid crystal rear projection (silicon-based LCOS), liquid crystal front projection, rear projection cathode ray tube, and cathode ray tube on March 31, 2006 Announced by the Ministry of Information Industry and implemented on January 1, 2007. At the same time, a total of 25 industries related to digital TV-related receiving terminals such as "" Digital TV receiving equipment terminology "and test methods, interfaces, set-top boxes, and machine card separation" to be implemented from March 31, 2006 are also announced. Recommended standards. It is worth noting that, because it is an industry-recommended standard, it is not mandatory, and any unit has the right to decide whether to adopt it. Violation of such standards does not constitute economic or legal responsibility. Such recommended standards can only be legally binding if they are accepted and adopted, or agreed by all parties to be included in an economic contract. The six digital TV display standards that were postponed and implemented on January 1, 2007 are precisely the standards for digital high-definition television display terminals, that is, the full name of the high-definition digital television display format is 1125/50/2: 1. Referred to as 1080 / 50i-16: 9, that is, the effective pixels are horizontal 1920 × vertical 1080, the scanning frequency is 50 fields, i refers to interlaced scanning, and 16: 9 is the aspect ratio, especially when displaying large movies. Advantage.

3. After the promulgation of the 25 digital TV terminal product industry recommended standards for high-definition digital TV related products, in line with the principles of promoting the healthy development of the industry, regulating the market, and guiding consumption, on April 11, 2006, the Ministry of Information Industry Digital TV Leading Group The Office decided that, in accordance with industry standards and relevant national regulations, the United Nations Certification and Accreditation Supervision and Administration Department, the China Quality Certification Center (CQC), will support product certification agencies such as China Electronics Standardization Institute (CESI) to carry out product certification work in the country. The certification marks of digital television products such as "high-definition", "standard-definition", and "separation of machine cards" will be carried out within the scope. Domestic and foreign television production enterprises can voluntarily go to the certification body authorized by the national certification and accreditation department to test and certify different types of televisions and other products produced by them in accordance with industry standards. Only through the certification of HDTV high-definition digital television receivers can the labels with the "high-definition" mark of the authoritative certification body be attached, so that consumers can learn the performance and functions of related digital TV products at a glance. Subsequently, many companies including Konka, TCL, and Haier claimed to have obtained the standard certification of digital high-definition television from the Ministry of Information Industry. And Panasonic, Hitachi and CCTV's high-definition cooperation with CCTV also got the HD certification logo.

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