Interpretation: LED display technology faces the challenge of QR code
Snap Frame,Poster Clip Frames,Aluminium Clip Frames,Poster Clip Frames SUZHOU JH DISPLAY&EXHIBITION EQUIPMENT CO.,LTD , https://www.jh-snapframe.com
Since the emergence of mobile phone QR code in 2002, the application of QR code in life has become more and more extensive, especially in the past two years, because QR code generation is very convenient, as a carrier of identification and information transmission, QR code Become a popular. The bus station scans the QR code and various business information will appear; the subway sells the QR code paper towel, sweeping it to get the local tourist map; even some people print their QR code on the WeChat account on the clothes. QR code has also become an indispensable part of many commercial promotion, and LED display is a common type of light box advertisement. Its display technology is not satisfactory in displaying the effect of complex two-dimensional code. Display technology presents various challenges. With the development and application of LED display (LED display) technology, the requirement for whether to display digital content in various applications is increasing. Taking the LED display of commercial advertisement as an example, the business owner has been giving the most of the short-term advertising time of about 30 seconds, giving more information to the consumers, and successfully attracting his attention, which has always been the most troublesome for business owners. Using the consumer's mobile phone, combined with QuickResponseCode (QRCode, hereinafter referred to as QR code), undoubtedly provides a very good consumer experience, but this application has further improved the technical threshold of LED display . Market Trends of QR Codes LED Related Research Report 2014-2018 LED Lamp Industry Domestic and Foreign Market Development Forecast and Investment Comparative Analysis Report 2014-2018 LED Display Industry Domestic and Foreign Market Development Forecast and Investment Comparative Analysis Report 2014-2018 LED Device industry domestic and international market development forecast and investment comparison analysis report May 2014 2014-2018 LED street lamp industry domestic and international market development forecast and investment comparison analysis report After the 1231970s, point of sale point information system (Pointfsale, POS) and bar code ( The emergence of Barcode) solves the problem that traditional retailers do not have a good tool to count the sales and inventory of goods, and to make Barcode popular, but new problems have followed. The problem is that Barcode has a limited capacity, and Barcode itself can represent up to 20 words in English. If the code itself is capable of containing more information, the demand will increase. In 1994, DENSOWAVEINCORPORATED revealed the QR code. The name of the QR code is derived from the QuickResponseCode (QRCode, hereinafter referred to as the QR code), also known as the 2D Barcode. The QR code can hold a large capacity of about 7000 English digits for Chinese character processing. And the reading speed is more than 10 times faster than other encodings. In 2002, mobile phone QR code usage rate began in 2002. The mobile phone with two-dimensional code reading function has been launched. This kind of graphic containing many information attracts people. It can be easily accessed by reading the mobile website or obtaining various discounts. Therefore, the QR code is rapidly spreading in society. According to independent research firm Forrester Research, Inc., on average, 15 consumers in the US, UK, France, and Germany are already using mobile phones to scan QR codes, and the proportion continues to grow. The basic working principle of LED display LED display is a display composed of modules. The resolution of length, width and size can be adjusted as required. However, the input source is fixed resolution, which is generally scaled by multimedia playback software. This makes it easy to change the original image ratio. The basic working principle of the LED display is line scanning, which illuminates the first line one after the other, and the second line, etc., from top to bottom, completely presents one frame of image, which is called static scanning. Considering the cost of the chip and the demand for the brightness of the light, the line scan is divided into 1~32 lines of scanning, but has the disadvantages of poor display effect and large brightness loss. The poor display performance includes a decrease in the refresh rate of the LED display. The refresh rate of the LED display is not enough. The application of the QR code on the LED display limits the QR code to ensure that the reading is correct when the display of the QR code is clear and conforms to the standard. This is in the e-mail (E-mail), When the Internet (Website) or the like can be displayed via a liquid crystal display (LCD), there is no problem. When applied to applications such as magazine printing, product packaging, business cards, etc., the QR code provides error correction for the above applications to be dirty, damaged, etc., and can correct up to about 30 to ensure reliable reading. take. However, as the basic operation principle of the above-mentioned LED display line scanning, when the two-dimensional code is applied to the LED display screen, the following error conditions are likely to occur and cannot be read. 1. Positioning pattern (Positiondetectionpatterns) The QR code can be quickly read from any direction of 360. The mystery lies in the three positioning patterns in the QR code. It can be explained that the QR code is not affected by the background pattern and is fast. Fixed reading. However, when the LED display performance is not good enough to achieve a high refresh rate (indoor LED display: refresh rate 500 Hz / outdoor LED display: refresh rate 1000 Hz), the three positioning patterns cannot be fully presented, and thus cannot be effectively positioned. 2. QRcodewhosemodulesaredistorted When the LED display is not efficient, high gray scale (14bit) cannot be achieved, and when the screenless processor is reduced or enlarged, it is easy to cause the distortion of each symbol (Codemodule), although the appearance It is the same as a normal QR code, but it is actually difficult to read, and sometimes it cannot be read. Two-dimensional code application LED display example The traditional switch type LED display can be divided into two types: the traditional switch type and the ScrambledPWM type. The conventional switch type drive chip includes JIX5020 and MBI5024. The traditional switch-type driver chip has three performances in refresh rate, grayscale level and LED light brightness. It is necessary to make trade-offs. For general application, in order to obtain high LED light brightness, high LED light brightness mode is selected, so even the refresh rate and gray scale Poor performance (indoor LED display: brush rate frequency 500Hz / outdoor LED display: refresh rate 1000Hz). When the QR code is applied to the high LED light brightness mode, scanning with a mobile phone may result in an inability to scan correctly. The traditional switch-type driver chip includes JIX5020, MBI5024, etc. The traditional switch-type driver chip is in practice, with the control system, and the high refresh rate mode can be selected. The LED display with 1:16 scanning is taken as an example, and the LED of the traditional switching technology is used. Drive the chip to broadcast the QR code picture. Most of the current two-dimensional codes have been designed with the background image. However, when the traditional switch-type driver chip is used to select the two-dimensional code image played in the high refresh rate mode, the gray scale is insufficient, so when using the mobile phone for scanning, The three positioning patterns and codes in the dimension code are confused with the background color, which makes the two-dimensional code unable to be significantly reduced. Because the color scale is insufficient, the shooting effect and the background image appear serious color patches, so that the advertising effect is also Great discount. Traditional switch-type driver chip - high gray scale, low refresh can not correctly read two-dimensional code Traditional switch-type driver chip including JIX5020, MBI5024, etc., traditional switch-type driver chip in practice, with control system, can choose high gray-scale mode, Taking a 1:16-scanned LED display as an example, a conventional switch-type LED driver chip is used to broadcast a two-dimensional code picture. The traditional switch-type driver chip is used to select the two-dimensional code played in the high-gray mode. Since the refresh rate is insufficient, when the mobile phone is used for scanning, the code symbols are deformed and cannot be read. The same for advertisers, the advertising effect is quite poor. Two-dimensional code application LED display example - ScrambledPWM type ScrambledPWM technology, improve the traditional pulse width modulation (PWM) technology, spread the time of one image conduction into several short on-times to increase the overall visual refresh rate. Therefore, compared to the traditional switch-type driver chip, the ScrambledPWM type can greatly improve the refresh rate (indoor LED display: refresh rate 500Hz / outdoor LED display: refresh rate 1000Hz), LED light brightness and gray scale, can effectively make two-dimensional The correct rate of code identification has been greatly improved. ScrambledPWM type driver chip - high gray level, high refresh correctly read QR code to accumulate technology ScrambledPWM type driver chip MBI5041, MBI5042, MBI515X series as an example (Figure 9), in various application environments, can ensure its refresh The rate is at least greater than 1,000 Hz, so as to ensure that consumers can quickly and effectively scan the QR code with mobile phones, catering to market trends and technology frontiers. The Accumulation Technology ScrambledPWM type driver chip can innovate the following benefits in the QR code market: 1. Ensuring the advertisement of the LED display screen enables the consumer to scan the QR code correctly and quickly. 2. High-gray color effect makes the LED display advertisement more colorful and multi-style design, and allows the reporter to capture the most beautiful image to achieve the effect of advertising.