How LED display technology meets the challenge of QR code
Since the advent of mobile phone QR codes in 2002, QR codes have become more and more widely used in life, especially in the past two years. Because QR codes are very convenient to generate, they are used as carriers of identity recognition and information transfer. Become a popular. Scanning the QR code at the bus station, various business information will appear; the subway sells QR code paper towels, and you can scan to get the local tourist map; even some people print their WeChat account QR codes on their clothes. Two-dimensional codes have also become an indispensable part of many commercial promotion, and LED display is a commonly used light box advertisement. Its display technology is not satisfactory in displaying complex two-dimensional codes. Display technology presents various challenges. With the development and application of LED Display (LED Display, hereinafter referred to as LED display) technology, the demand for whether it can completely present digital content in various applications has increased. Taking the LED display of commercial advertising as an example, business owners have always been the most troubled business owners how to make full use of the short advertising period of about 30 seconds to present more information to the customers who come and go and successfully attract their attention. Using consumer mobile phones, combined with QuickResponseCode (QRCode, hereinafter referred to as QR code), undoubtedly provides a very good consumer experience, but this application also further improves 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 comparison analysis report 2014-2018 LED display industry domestic and foreign market development forecast and investment comparison analysis report 2014-2018 LED device industry domestic and foreign market development Forecast and comparative investment analysis report In May 2014-2018-2018 LED street lamp industry domestic and foreign market development forecast and investment comparison analysis report 1231970s, the emergence of point-of-sale information systems (Pointfsale, POS) and bar codes (Barcode), solved the problem Good tools can count the problems of merchandise sales and inventory, and also make Barcode popular, but new problems also follow. The problem is that the capacity of the barcode (Barcode) is limited. The English number represented by the barcode (Barcode) itself can only hold up to 20 characters. The demand for "Code (code) as long as it can contain more information" is increasing. In 1994, DENSOWAVEINCORPORATED published the QR code. The name QR code is derived from the Quick Response Matrix Code (QuickResponseCode, QRCode, hereinafter referred to as QR code), also known as 2D Barcode (2DBarcode). The QR code can accommodate a large capacity of about 7000 English digits and can be processed by Chinese characters , And the reading speed is more than 10 times faster than other codes. Mobile phone QR code usage rate by country In 2002, mobile phones with QR code reading function began to market. This kind of graphics, which contains a lot of information, attracts people. By reading, you can easily visit mobile phone websites or obtain various discounts. Popular in society. According to Forrester Research, Inc., an independent research institute, on average, 15% of consumers in the United States, Britain, France, and Germany are already using mobile phones to scan QR codes, and the proportion continues to grow. Basic working principle of LED display The LED display is a display composed of modules. The resolution of its length, width and size can be adjusted arbitrarily according to requirements. However, the input message source is a fixed resolution. Generally speaking, it is zoomed through multimedia playback software, which is easy to make the original image The ratio changes. In addition, the basic working principle of the LED display is line scanning. The first line is lit successively, and the second line is displayed from top to bottom, and a frame of images is completely presented. Considering the cost of the chip and the demand for luminous brightness, line scanning is divided into 1 ~ 32 line scanning, but it has the disadvantages of poor display effect and large brightness loss. The poor display effect includes the reduction of the refresh rate of the LED display. Insufficient refresh rate of LED display Restrictions on the application of QR codes to LED displays The QR code can only be read when the QR code is clear and in compliance with the standard. This can be displayed on the LCD (Liquid Crystal Display, LCD) in e-mail, Internet, etc. There will be no problems. When applied to applications such as magazine printing, product packaging boxes, business cards, etc., the QR code provides error correction function in response to the above applications becoming dirty and damaged, etc., and can correct up to about 30% to ensure that it can be determined. Read. However, as the basic working principle of the above-mentioned LED display line scanning, when the QR code is applied to the LED display, the following error conditions are prone to occur and cannot be read. 1. Three positioning patterns (Positiondetectionpatterns) The two-dimensional code can be quickly read from any direction of 360 °. The secret lies in the three positioning patterns in the two-dimensional code, which can explain that the two-dimensional code is not affected by the background style and realizes rapid reading. However, when the performance of the LED display is not good enough to achieve a high refresh rate (indoor LED display: refresh rate 500Hz / outdoor LED display: refresh rate 1000Hz), the three positioning patterns cannot be fully presented, and therefore cannot be effectively positioned. 2. Symbol deformation (QRcodewhosemodulesaredistorted) When the LED display performance is not good, high gray scale (14bit) cannot be achieved, and when it is reduced or enlarged without a matching video processor, it is easy to cause the deformation of each code module (Codemodule), although the appearance is the same as the ordinary QR code , But it is actually very difficult to read, sometimes even unreadable. Two-dimensional code application LED display example-traditional switch type LED display screens can be divided into traditional switch type and ScrambledPWM type according to different driver chips. Taking the accumulation technology chip as an example, the traditional switch type driver chip includes JIX5020, MBI5024, etc. The traditional switch type driver chip has a refresh rate and gray scale. The three functions of level and LED lamp brightness need to be selected. For general applications, in order to obtain high LED lamp brightness, the high LED lamp brightness mode will be selected, so that even if the refresh rate and grayscale performance become poor (indoor LED display: brush rate Frequency <500Hz / outdoor LED display: refresh rate <1000Hz). The QR code is used in the high-brightness LED mode. When scanning with a mobile phone, it may fail to scan correctly. Traditional switch-type driver chips include JIX5020, MBI5024, etc. In practice, the traditional switch-type driver chip is matched with a control system to select a high refresh rate mode. Take the LED display of 1:16 scan as an example, using traditional switch-type LED technology Drive the chip to broadcast the QR code picture. Most of the current QR codes have been designed to match the background image, but when using the traditional switch-type driver chip to select the QR code image played in the high refresh rate mode, due to the insufficient gray scale, when using the mobile phone to scan, two The three positioning patterns and codes in the dimension code are confusing with the background color, which makes the QR code unrecognizable. The recognition rate is greatly reduced; due to the insufficient color scale representation, the shooting effect and the background image have serious color blocks, which also make the advertising effect. Great discount. Traditional switch-type driver chip-high gray level, low refresh can not read QR code correctly Traditional switch-type driver chips include JIX5020, MBI5024, etc. In practice, the traditional switch-type driver chip is equipped with a control system to select a high grayscale mode. Take the LED display of 1:16 scan as an example, using traditional switch-type LED technology Drive the chip to broadcast the QR code picture. The traditional switch-type driver chip is used to select the two-dimensional code played in high grayscale mode. Due to the insufficient refresh rate, when the mobile phone is used for scanning, each code module (Codemodule) is deformed and cannot be read. Similarly, for advertisers, their advertising effectiveness is quite poor.
The splicing touch frame is an important part of the touch splicing screen system. Compared with other media propaganda carriers, the touch splicing screen reflects the extensiveness, intuitiveness, and fun of human-computer interaction and presentation, and has a strong visual impact. It has made a big step forward in the development of the touch industry. It is also a promoter of super-sized display integrated touch. The large-sized spliced touch TV display wall has involved schools, shopping malls, banks, digital exhibition halls, corporate exhibition halls, and government Institutions and military command can be equipped with digital content, interactive games, animation, 3D, VR, interactive audio and video, etc. It is an indispensable and effective application device for today's interactive large-screen demonstrations.
pictures show
Large Infrared Touch Frame (Splicing) Large Infrared Touch Frame,Large Splicing Infrared Touch Frame,Ir Multi Touch Frame,Led Touch Screen TV Wall,Large-size Infrared Touch Screen,LCD Touch Screen TV Wall ShenZhen GreenTouch Technology Co.,Ltd , https://www.bbstouch.com
