Digital TV set-top box

Development

In 2010, my country's digital TV set-top box industry entered a business cycle of market structure adjustment and in-depth development. 2010 was a year of rapid development of China's digital TV set-top boxes, and the industry market developed steadily. Data from the National Bureau of Statistics show that in 2010, there were 317 digital TV set-top box enterprises above designated size; assets totaled 21.134 billion yuan; sales revenue was 21.448 billion yuan, a year-on-year increase of 30.65%; total profits were 1.092 billion yuan.

In September 2010, the State Administration of Radio, Film and Television issued the "Notice on Further Promoting and Regulating the Development of HDTV", proposing to take effective measures to ensure HD broadcast, effectively strengthen the production and purchase of HD programs, and further increase HD channels Broadcast, effectively strengthen the transmission of high-definition channels into the network, and further strengthen the promotion and marketing of high-definition TV. The important significance of this "Notice" is that through the promotion and guidance of the government, it can increase the source of high-definition programs and enrich the content of high-definition programs, thereby promoting the overall development of the high-definition market. In 2010, my country's HD market entered a period of development.

With the increase of high-definition program sources and the increase of interactive services, high-definition two-way set-top boxes have gained the attention of cable operators. Operators in Beijing, Shenzhen, Shanghai, Hangzhou, Chongqing, Guangxi and other places are developing high-definition on a large scale and have achieved good results. Under the leadership of cable operators in these cities or provinces, cable operators in other cities across the country have launched local HD services.

Product introduction

Digital TV set-top box is a conversion device that converts digital TV signal into analog signal. Digital TV set-top box has become an embedded computing device with perfect real-time The operating system provides powerful CPU computing capabilities to coordinate and control various parts of the hardware facilities of the set-top box, and provides easy-to-operate Graphical User Interface (GUI), such as an enhanced TV electronic program guide, which provides users with pictures and texts. Program introduction and background information.

It is also a new type of household appliance that expands the functions of the TV. It is responsible for converting various received information (including TV programs) into a realistic format for the TV to display on the screen. At the same time, the set-top box It has the capability of a "dumb computer". In this way, through internal software functions and a slight two-way transformation of the network, it is easy to realize a variety of services such as Internet browsing, video on demand, home e-commerce, telephone communication, etc., which can be described as one network.

When TV transitioned from black-and-white TV to color TV, a compatible method was adopted, and the PAL-D system has continued to this day in China. The transition from analog TV to high-definition digital TV is a leapfrog transition. It can be said that it is not directly compatible, which means that all analog TVs cannot be used, so it is unrealistic to achieve one step. Countries have adopted a transitional type. The method-the digital set-top box, which effectively avoids the interference and loss caused by the TV signal in the transmission process, and the quality of the signal received by the TV has been greatly improved. This is just a transition, because the scan line of analog TV has been fixed, so it has a considerable distance compared with high-definition digital TV.

High-definition digital TV (HDTV) is the future development direction. Analog TV has been eliminated, and the radio, recording, and editing equipment of TV stations has also been replaced accordingly. What people see on TV screens will be high With clear TV pictures and more functions, HDTV will bring TV into a new era.

Someone asked if the signal received by the digital set-top box was a high-definition digital TV? No, after using a digital set-top box, the digital signal is converted into an analog signal and input to the analog TV to display information. This way, although the quality of the signal received by the TV has been greatly improved, since the scan line of the analog TV has been fixed, it is compatible with Compared with high-definition digital TV, there is still a considerable distance. This is just a transition.

Interface

1, signal input

2, signal loop output

3, RCA (video and video interface)

4, YPbPr (component output)

5, S-VIDEO (S-video interface)

6, SPDIF (digital audio)

7 , USB2.0 (can be connected to external devices, such as: mobile hard disk, U disk)

8, network interface (to achieve interaction, you click me to play)

9, HDMI (high-definition Interface)

Hardware structure

1, mainboard

2, switching power supply Power board

3, remote control and key control panel Front PCB

4, Tuner

5, radio frequency modulator RF

6, upgrade serial port RS-232

7 , Flash memory Flash

8, audio and video output interface RCA, SPDIF, HDMI

9, conditional access system CA module

main technology

Channel decoding, source decoding, upstream data modulation and coding, embedded CPU, MPEG-2 decompression, set-top box software, display control and descrambling technology are the main technologies of digital TV set-top boxes.

Channel decoding

The channel decoding circuit in the digital TV set-top box is equivalent to the tuner and intermediate frequency amplifier in the analog TV. In the digital TV set-top box, the tuner is necessary, but the tuning range includes satellite channels, terrestrial TV receiving channels, and cable TV supplementary channels. According to the existing modulation methods of DTV, channel decoding should include QPSK, QAM, OFDM, and VSB demodulation functions.

Source decoding

After the analog signal is digitized, the amount of information increases sharply, and corresponding data compression standards must be adopted. Digital TV broadcasting adopts MPEG-2 video compression standard, which is suitable for multiple definition image quality. Audio has two standards, AC-3 and MPEG-2. The source decoder must adapt to different coding strategies and correctly restore the original audio and video data.

Modulation and coding

To develop interactive applications, it is necessary to consider the modulation and coding of uplink data. There are three commonly used methods, using telephone lines to transmit uplink data, using Ethernet cards to transmit uplink data, and transmitting uplink data through a wired network.

CPU

Embedded CPU is the heart of the digital TV set-top box. After the data is decoded in the channel, it must first be demultiplexed, and the transport stream is divided into video and audio so that the video and audio Separate from the data, more than 32 programmable PID filters are integrated in the dedicated CPU of the digital TV set-top box, two of which are used for video and audio filtering, and the rest are used for PSI, SI and Private data filtering. The CPU is the operating platform of the embedded operating system. It must work with the operating system to complete network management, display management, conditional access management (IC card and Smart card), teletext decoding, data decoding, OSD, video signal up-down conversion And other functions. In order to achieve these functions, it is necessary to expand many new functions on the ordinary 32~64 bit CPU, and continuously improve the speed to meet the requirements of high-speed network and three-dimensional games.

MPEG-2 decoding

MPEG-2 is one of the key technologies in digital TV. The practical video digital processing technology is basically based on MPEG-2 technology. -2 is the entire specification including transmission from the network to the high-definition television. MP@LL is a subset of H.263 and H.261 used for VCD, video conference and video phone. MP@ML is used for DVD and SDTV, and MP@HL is used for HDTV.

The MPEG-2 image signal processing method is divided into 4 steps: motion prediction, DCT, quantization, and variable length coding. The circuit is composed of an ASIC circuit with a RISC processor as the core.

MPEG-2 decompression circuit includes video, audio decompression and other functions. To complete the main picture and sub-picture decoding in video processing, it is best to have a layered decoding function. Teletext can be optionally added to the main screen with the APHA overlay function. This requires the decoder to demodulate the main screen image and teletext data at the same time, with high speed and processing capabilities. OSD is a layer of monochrome or pseudo-color subtitles, mainly used for user operation prompts.

In terms of audio, since DVB in Europe uses MPEG-2 audio and ATSC in the United States uses Dolby AC-3, audio decoding must have the above two functions.

Set-top box software

After TV is digitized, software technology occupies a more important position in digital TV technology. In addition to the audio and video decoding implemented by hardware, it includes the reproduction of TV content, the realization of the operation interface, the realization of the data broadcasting service, and the interconnection between the set-top box and the personal computer and the interconnection with the Internet all need to be realized by software, as follows:

1. Hardware driver layer software: Drivers drive hardware functions, such as radio frequency demodulator, transmission demultiplexer, A/V decoder, OSD, video encoder, etc.

2. Embedded real-time multitasking operating system: The embedded real-time operating system is relative to the desktop computer operating system. It is not installed in the hard disk. The system has a compact structure, relatively simple functions, and open resources. The capital is small, and it is easy to be solidified in the memory. The role of the embedded operating system is similar to that of DOS and Windows on the PC. The user conducts man-machine dialogue through it to complete the designation given by the user. The designated receiving adopts multiple methods such as keyboard, mouse, voice, touch screen, infrared remote control, etc.

3. Middleware: The characteristic of an open business platform is that product development and production are based on a business platform. The open business platform provides an independent operation mode for each link, and each link has Its own profits can generate multiple suppliers. Only by adopting an open service platform can the scalability of the set-top box and the effective recovery of investment be ensured.

4. Upper-level application software: Perform various service functions provided by service providers, such as: electronic program guide, quasi-video-on-demand, video-on-demand, data broadcasting, IP phone and video phone, etc. The upper application software is independent of the STB hardware, and it can be used on various STB hardware platforms to eliminate the dependence of application software on the hardware.

Display technology

As far as TV and computer monitors are concerned, CRT display is a mature technology, but low-resolution TVs are used to display text, especially smaller than 24×24. The problem becomes complicated. The picture tube of the TV is a large-pitch low-resolution tube, which is only suitable for displaying 720×576 or 640×480 images. Its deflection system is fixed and is designed for 525-line 60Hz or 625-line 50Hz. There are more than 18 digital TV display formats. Internet access must comply with the VESA format. Obviously, the display system of the TV cannot adapt to so many formats. In addition, the TV uses a low frame rate interlaced scanning method. When displaying graphics and text, the brightness signal has background flicker, and the horizontal straight line has flicker between lines. If the progressive scan computer graphics are converted to a TV, the horizontal edge will only appear in the odd or even field, and the screen display time is close to the visual persistence of the human eye, which will cause severe edge flicker, so a TV is required. To access the Internet, it is necessary to remedy the defects of the TV display.

According to the technical difficulty and cost, two methods are used to improve. One is the anti-flicker filter, which proportionally adds the images of three adjacent lines into one line, so that the images only appear in a single field Reproduced in each field, this method is called three-line filtering. The three-line filtering method is simple and easy to implement. However, it reduces the clarity of the image and is suitable for interlaced TV sets. The other method is to change the interlaced scanning to progressive scanning, and increase the frame rate appropriately. This method should double the number of lines and fields scanned, in order to make the increased number of images not out of thin air, and to ensure the continuity of the active picture It is necessary to perform line and field interpolation operations and motion compensation, and it must be realized with a dedicated chip and complex technology. This method of displaying computer graphics on the TV has very good quality, but it must be line-by-line and doubled. The scanning function can only be realized on the TV. In addition, when HDTV and VESA signals with a higher resolution than an analog TV are played on the TV, only part of the picture can be displayed and must be reduced. This is like the PIP method, where lines and fields are lost. Similarly, in order to ensure the continuity of the image, an interpolation operation must be performed.

Scrambling and descrambling technology

Scrambling and descrambling technology is used to encrypt and decrypt digital programs. The basic principle is to use scrambled control word encryption transmission method, and the user terminal uses IC card to decrypt. In the MPEG transport stream, there are two data streams related to the transmission of control words: authorization control information (ECMs) and authorization management information (EMMs). The control word encrypted by the service key (SK) is transmitted in ECMs, including program information such as program source, time, content classification, and program price. The service key that encrypts the control word is transmitted in the authorization management information, and the service key must be encrypted by the user's personal distribution key (PDE) before transmission. EMMs also include addresses and user authorization information, such as programs or time periods that users can watch, and viewing fees paid by users.

The user’s personal distribution key (PDK) is stored in the user’s smart card (Smart Card). On the user side, the set-top box obtains the PID values ​​of EMM and ECM according to the CA-descriptor in the PMT and CAT tables. Then filter out ECMs and EMMs from the TS stream, and send them to the Smart Card through the Smart Card interface. Smart Card first reads the user’s personal distribution key (PDK), uses PDK to decrypt EMM, takes out SK, then uses SK to decrypt ECM, takes out CW, and sends CW to the descrambling engine through the Smart Card interface. Using CW, the scrambled transport stream can be descrambled.

Conditional Access System

(CAs:Conditional Access System)

Conditional Access System (CAS) is the core technology of pay TV, understand its operation The mechanism, mastering its use and maintenance are critical to the successful development of pay TV services. CAS consists of: user management system SMS, business information generation system SIG, program management PMS/SI editing system, program scheduling processing EIS, user authorization management system SAS, conditional access CA, etc. There are two main blocks: one is the SMS that manages users, and the other is the CA that manages programs. CA is mainly divided into two parts: one is the signal scrambling part, which uses a random code (called control word CW) generated by a random code generator to control the scrambling of the signal by the scrambler; the other is the encryption part In order to successfully descramble the scrambled signal at the receiving end, the receiving end must also have the same control word as the scrambling end to control the descrambler. Therefore, the CW of the front end must be transmitted to the receiving end. It will be easily intercepted by hackers and make CAS useless. For this reason, CW must be encrypted for transmission. This encryption is a multi-layer encryption mechanism to increase the security of CW transmission and directly encrypt the first layer of CW encryption. The generated ciphertext is called authorization control information ECM, which is transmitted together with the scrambled code stream through a multiplexer. ECM also contains information such as time, program price, program authorization control, etc., so ECM is program-oriented management information. The key to encrypt the CW is called the working key SK. SK is usually called the monthly key. It is changed once a month. Every time SK is changed, the system must re-authorize all users. The second layer of encryption is to use the program key PDK to encrypt the SK. The generated cipher text and the authorization instructions obtained from the SMS form the authorization management information EMM generated by the SAS. The EMM also contains the smart card number, authorization time, User authorization information such as authorization level. This information is mainly to complete the authorization of the user, so EMM is user-oriented management information. The EMM authorizes the user at what time and what channel to watch, and it is also transmitted through the multiplexer and the scrambled code stream. The above composition The most basic encryption system of CA.

Development status

Digital TV set-top boxes will change our existing TV concept, and will also provide a brand-new consumer terminal for the Internet, and this consumer terminal will be better than any other terminal. PCs, mobile phones, and PDAs are popular, convenient and attractive. With the trial broadcasting of digital cable TV in various places, the promotion of digital TV set-top boxes has made great progress compared with a few years ago. However, digital set-top boxes have not been widely used in China. There are several reasons for this:

There are not many real products. In fact, most of the VOD (Video on Demand) of many manufacturers are in the conceptual stage.

Quality issues

Because the digital TV set-top box is greatly restricted by the network bandwidth, especially the current domestic network development foundation is weak, and various network resources are in separate formations, so its wide range Popularization and promotion will take time.

Insufficient service

That is, the lack of information and program resources. For example, a major difficulty in the promotion and application of VOD services is the openness of program sources, film sources, and copyrights. The establishment of the national cable television backbone network and the emergence of professional film providers can alleviate this problem to a certain extent. Many manufacturers have developed VOD systems based on hotels, hotels, and communities in order to avoid this problem.

The tariff is too high

It is also not a small expense for most users. The consumer psychology of the Chinese is that they can bear a large one-time purchase cost, but they are not willing to accept long-term continuous consumption payments without obvious returns.

Current status of the industry

China's set-top boxes are developing rapidly. As the resource supply or product demand of the set-top box industry is undergoing a series of changes, the industry is gradually shifting from other countries or regions to production and manufacturing in China. China has become the world's largest set-top box manufacturing center. In 2007, the Chinese set-top box market was dominated by wired set-top boxes. The set-top box market has shipped more than 65 million units, an increase of 41.3% compared to 2006. The domestic shipment of set-top boxes exceeded 30 million units, an increase of 49.32% compared to 2006. The domestic market’s set-top box shipments exceeded foreign markets for the first time; the number of cable set-top boxes in the market exceeded 25 million at the end of 2007, an increase from 2006 Nearly 60%. In 2008, China's digital TV entered a period of vigorous development. In addition to cable digital TV still showing a strong growth momentum, terrestrial digital TV also has a breakthrough development with the opportunity of the 2008 Olympic Games. In 2008, despite the impact of objective factors such as snow disasters, earthquakes, and the global financial crisis, China's set-top box market was still in a business cycle.

According to the "Tenth Five-Year Plan for Radio, Film and Television Technology and the 2010 Long-Term Plan", China will fully realize digital radio and television in 2010, and stop analog radio and television broadcasting in 2015. Undoubtedly, the popularization of digital TV programs has become an inevitable trend, and China's current "analog TV + set-top box" conversion form has created huge business opportunities in the set-top box market.

Development Trends

It is reported that federal regulatory regulators have adopted new equipment standards in the eastern United States to accelerate the transition to higher audio and video quality digital TVs.

The Federal Communications Commission (FCC) voted 5 to 0 to pass a device standard that allows digital TV signals to be directly connected to TV sets without the need for set-top boxes and additional cables. In order to watch pay TV, users have to insert a security card provided by their cable service provider into the TV.

Manufacturers hope to sell high-definition televisions with this plug-and-play technology. They said that the Federal Communications Commission's decision will increase consumer demand and stimulate companies to increase production and further popularize this new type of television.

Different from the traditional analog TV, the digital TV signal uses computer language, its image is clearer, and it also has other potential features, such as Internet access, video games, and multiple sets in the same channel Show etc. Digital signals can be transmitted via satellite, cable or wireless broadcasting.

Digital TV system can basically be divided into front-end hardware system (including multiplexer, scrambler, modulator, digital TV set-top box in the figure), software system (CAS, SMS, EPG, data broadcasting) And a series of servers) and digital TV set-top box 3 parts.

In the overall conversion cost of digital TV, the investment in set-top boxes occupies an absolute share, reaching more than 90% of the entire investment. Because of the huge capital involved, every movement in the digital TV set-top box market can cause severe vibrations to the overall digital TV conversion in the country.

The principle and structure of the set-top box are shown in Figure 1. It can be seen that the structure of the set-top box is relatively simple. From the structural point of view, the set-top box is generally composed of the main chip, memory, tuner and demodulator, return channel, CA (Conditional Access) interface, external storage controller, and video and audio output. The most important part is the main chip and the tuning demodulator. The difference between these two parts determines the performance and price of the set-top box to a large extent.

At present, there are many kinds of CA, downloader, EPG, data broadcasting and middleware systems in the market of our country, and various value-added applications are even more diverse. The threshold for R&D, production, marketing and technical support of set-top box manufacturers has been greatly improved. It is difficult for set-top boxes to be mass-produced, reduce costs, and improve reliability. On April 3, 2010, the Ministry of Information Industry announced the digital TV card separation standard (technical specification SJ/T 11336-2006 and test specification SJ/T 11337-2006). The implementation of this standard can reduce the functions of the set-top box and reduce the cost of the set-top box; the second is to increase the functions of the expansion interface and carry out value-added services to increase the income; The business depends on the expansion products that the people already have or purchased to reduce repeated investment; fourth, it strongly supports the production and research and development of digital TV all-in-one machines (the set-top box is built into the TV); the fifth is the "home appliance" Sales outlets move from online companies to home appliance stores, allowing users to independently choose the brand of set-top boxes, which can effectively reduce the pressure on online companies’ sales funds and after-sales services.

In addition, based on the advantages of multiple CA, downloader, EPG, data broadcasting and middleware systems of digital TV set-top boxes, external plug-ins are integrated with them, and the value-added application integrating home appliances, electronics and value-added services makes Digital TV set-top boxes tend to be industrialized and market-oriented. Take TV somatosensory games that have received much attention as an example. International giants such as Nintendo, Sony and Microsoft are all ready to cooperate with domestic high-definition digital TVs and digital set-top boxes, and want to cooperate with them to insert high-definition somatosensory game value-added services, which is also the current high-definition digital set-top box. One of the mainstream of development. Konka, the first domestic digital set-top box open application platform, has cooperated with Guangzhou Daidaixing Electronic Technology Co., Ltd., making the somatosensory game independently developed by Daidaixing become the standard configuration of Konka hardware. Based on Konka’s unique ten-core "Sharp core" technology, Through the open SDK software development tools, any application of the colorful motion-sensing game can run smoothly. For detailed technical interpretation, please refer to reference materials. That is to say, consumers can play 3D games in their own living room, and the somatosensory game developed by Dai Daixing is to control the actions of the game characters by body movements to achieve the effect of integrating entertainment and sports. It is a new way of living room entertainment.

Benefits

The digital set-top box is not only a user terminal, but also a network terminal. It can make the analog TV switch from passively receiving analog TV to interactive digital TV (such as video on demand, etc.), and It can access the Internet, enabling users to enjoy a full range of information services such as TV, data, and language. Some people think that the set-top box is used to make the TV go online, which is a misunderstanding. In fact, the digital set-top box is one of the members of the broadband integrated information network before the popularization of digital TV. With the development of digital technology, multimedia technology and network technology, the built-in and overall cost of digital set-top boxes will be reduced, allowing most users to realize multiple services such as entertainment and Internet access on ordinary analog TVs.

In short, as a digital TV iconic product, set-top boxes have a broad space for development. With the development of digital TV applications, chip technology and software technology, STB's functions are bound to become more and more powerful, and can provide operators and users with more services to meet the needs of different levels.

Controversy

The top 10 crimes of digital TV:

①The most uncomfortable: the speed of changing channels is slow, and there is a "standstill period" of a few seconds;

②The most disturbing people: the volume of each station is not uniform;

③The most depressing: frequent "mosaics";

④The most hateful: crashes become commonplace;

⑤The most annoying: the price has nearly doubled, and the program is almost the same as in the past;

⑥The most disappointed: the high-definition program becomes the moon in the water;

⑦The most annoying: the remote control opens the bow left and right ;

⑧The most retrogressive: TV has become a monitor for the whole family;

⑨The most unreasonable: the set-top boxes of household appliances also monopolize the monopoly;

⑩ The most overbearing: forced conversion, without giving consumers the right to choose.

Classification

1. Classification according to different transmission media: digital terrestrial television (DVB-T); digital cable television (DVB-C) (including optical fiber, copper shaft and both Hybrid network "HFC"); satellite digital television (DVB-S); IPTV set-top boxes based on IP protocol television broadcasting services, etc...

II. Classification according to definition: standard-definition digital TV set-top boxes SD STB (Standard Definition); HD STB (High Definition) for high-definition digital TV set-top boxes

3. Classification according to whether it can be descrambled: Free set-top box FASTB (FTA=Free To Air), which refers to only Set-top box for receiving free programs; conditional receiver set-top box CA STB, CA= Conditional Access; CI set-top box CI=Common Interface.

Working principle

The working principle of digital set-top box sharing machine: the encrypted signal is input through the input terminal, and the interference signal (scrambling encryption) is removed by its internal circuit, and then output The terminal outputs a normal signal. Whether the decryption circuit works or not has an external condition, which is the signal fed back by the TV tuner. If this signal is not fed back to the set-top box, the descrambling circuit will not work, and the undecrypted signal will still be output, so it cannot be watched normally. But why can only one set-top box be connected to one TV set? Can one set-top box connect to multiple TVs?

First put the set-top box near one of the TV tuner so that it can be watched normally, and then use the splitter to branch the signal from the output end to the other TV. One disadvantage of this approach is that another TV can only receive 5 channels near the channel that TV 1 receives. Then use a non-AND circuit or a 555 circuit to make an open multi-resonator whose resonant frequency can cover the entire frequency band of the cable TV. Place this resonator next to the set-top box. Let the set-top box receive the signal from the vibrator, and then use the splitter to branch out multiple TV sets from the output end of the set-top, so that all the TV sets can receive the signals of all channels. Finally, use a high-frequency transistor such as 9018 to make a high-frequency transmitting circuit, and use the radio frequency output to transmit again. As long as the transmitting power is small, the set-top box can receive it. Or use the coaxial video cable branch to connect to the input or output end, remove the outer shielded wire, and leave only the middle wire about 1 meter long, and wind this wire around the set-top box. Let the leaked signal be induced to the set-top box to receive.

Use and maintenance

1. Maintenance after shutdown and stop

Maintenance of the hard disk player, including wiping dust and dirt, For charging maintenance, etc., you must shut down first, and perform maintenance operations after stopping use. It is best to disconnect from the computer and TV, and then clean and maintain it to avoid electric shock, short circuit and other hazards. Some users like to wipe the hard disk player during the process of playing music and movies. This does not meet the maintenance requirements. It also contains various dangers and should not be operated in violation of regulations.

Second, keep the hard disk player away from the magnetic field

The main components of the hard disk player use magnetic media, so it must be kept away from the magnetic field, otherwise the hard disk Will be magnetized and lose data. Common sources of magnetic fields are speakers, speakers, mobile phones, and so on.

Three, pay attention to the environment and conditions of use

The hard disk player should not be used under high temperature. High temperature will change the frequency of the crystal oscillator in the hard disk. Generally, it is not suitable to be used next to a blast furnace and not to be used in an extremely hot site. If you have to use it under high temperature conditions, add necessary cooling equipment to prevent the hard drive from malfunctioning due to overheating.

Four. Pay attention to moisture, water and mildew

The hard disk player must be kept dry and clean. Once the hard disk in the hard disk player gets wet, it will cause an internal short circuit, which can cause data loss in the slightest, and destroy the hard disk in the worst case. Therefore. When using the hard disk player, pay special attention to keeping it away from water, prevent water droplets, and prevent mold. It is best to put the hard disk player in a special protective cover. This can not only avoid sweat erosion, but also prevent the player shell from being scratched by hard objects.

Five. Avoid strong vibration

When moving, please handle with care to avoid damaging the hard disk player. Be careful when using it and avoid severe vibrations. According to the working principle of the hard disk player, the hard disk and the flash memory work in different ways. The head and the disk are very close when the hard disk is read and written. At this time, if the hard disk is subjected to strong vibrations, it may damage the hard disk. The hard disk is scrapped. Therefore, it’s best not to move the hard disk player in a violent sports scene, and to keep the environment stable when carrying and using the hard disk player. It is best to wear a silicone protective cover for the hard disk player at ordinary times. This cover can play a buffering role. Protect the hard disk player from accidental vibration and cause problems.

Six. Use the battery correctly

Hard disk players generally use large-capacity lithium batteries. For lithium batteries, frequent charging will reduce battery usage Life span. Therefore, in general, it is best to charge when the battery is about to run out. If the battery is removable, it is recommended to buy multiple battery wheels. When using the first battery, charge the second battery and use it alternately. This also prevents the player from being unusable due to a sudden dead battery. Situation.