 |
简体中文 | English | ||||||||||||
|
|
|
|
|
LED screen construction A panel represents a built-up construction, which is built of light moistureproof LED modules, which are strictly docked for seamless image over the screen surface. The base of every square module with side length of about 0,4 m. is a special cast aluminum frame. The docked modules make a rugged structure. Due to special constructive solutions each module can be easily and rapidly extracted out of the panel, if it is necessary to change it. The modules construction enables to install the panel field in frames, which are special designed and fabricated by local companies for each specific installation. Brightness For outdoor or indoor LED screen, but under conditions of direct street light (for example showwindow), there are used light-emitting sources of bright light type. So, for normal viewing of the image on the LED screen in translucent rays of the sun it is necessary to use light-emitting sources with light intensity of 1,2…3 candellas.( note: 1 candella has the same light intensity as a light bulb of 1 W). For indoor installation it can be used light-emitting sources with far less power. Usually 30…150 millicandellas are enough. The color-reproduction quality and light intensity are defined by type and number of diodes of each color, which compose one pixel pitch. The highest light intensity and natural color transfer can be reached by using of high efficiency (high-light) diodes as parts of a pixel pitch. The maximal brightness of the panel at color temperature from about 6500 K is from 7000 Cd/m2 up to 18000 Cd/m2. In this mode all diodes light with the maximal brightness, but the composition of red, blue and green colors does not build up a clear white color. For recovery of a standard color palette it is required to balance the light intensity of single diodes; that brings to 15% brightness reduction from the original rate. Standard ratios of red, blue and green at the temperature of 6500 K will be: 63% RED, 100% GREEN, 55% BLUE. The EKTA methods enable to reach the given intensity level from 6000 Cd/m2 up to 9500 Cd/m2 at more than 99% brightness uniformity of the panel surface. Chromaticity All the LED screens are divided into 3 big groups: monochrome (of one screen color), multicolored and full-color. In monochrome LED screens You only should choose, what color is preferred. Mostly it is used 3 colors- red, green, yellow. By full-color LED screens it is meant products with full range of colors presentation, up to 16,7 million colors; multicolored LED screens display limited colors number: from 3 up to 65538 colors. Resolution capability Physical resolution is a very important characteristic for full-color LED screen. This is one of the most important things. Resolution capability works out at the number of addressable points or pixel pitches. The higher the physical resolution or pixel density is, the more qualitative the picture on LED screen is. There is a number of standard resolutions: 160x120; 320x240; 640x480 etc. So, the higher the numerical value of the resolution is, the more detailed the picture is. But due to working with unique technology of "virtual pixel" we managed to make the optical resolution twice as high as the physical resolution. The system concept consists in control of light intensity of single diodes in a module. Signal processing Panel control system enables to receive any signal source (video signals of PAL/SECAM/NTSC format, signals of digital format DVI, component signals with resolution up to SVGA), to make scaling and signal format interchange, to add effects if necessary. Video picture Most worldwide used LED screens display computer graphics and animation. But there is a special group of LED screens (generally, they are very expensive), which are able to display video picture from TV, video camera, videorecorder, or other video sources (in point of fact, a huge TV). The distance between indicating elements (pixels) is called pixel pitch. The shorter this distance is, the more pixels are located on 1 m2 of the screen, the higher image definition is and the higher the price of LED screen is. Automatic image setting The panel control system includes automatic light intensity adaptation system, which works proceeding from changing of faceplate illumination. This function enables to improve image perception comfort in wide range of illumination: from direct sunlight to intense darkness, and enables to establish the best diode light emission mode as well, that extends their service life and reduces the power demand. Image angle Horizontal visibility zone of the panel of LED-Wall range is equal to 140 deg.; vertical visibility zone is equal to 60 deg.. The optimal image angle corresponds to the normal to the panel surface. These values do not mean, that the picture on the panel is not visible at the angle of more than ± 70°. and 40+20°. respectively. But the light intensity level at such image angles will be less than 50% of the nominal (normally). Viewing distance The minimal viewing distance is defined by pixel size of LED panel. This distance is defined with account of the ability of the human eye to perceive separate the two pixels, which are spaced-apart to a prescribed distance. If this distance is shorter, the viewer will be able to see some separate diodes, which means that the formation of the color dot through the confluence of light fluxes of separate light sources in a pixel will not take place then. Resolution and occupation density of a module with light-emitting diodes are very important characteristics of the LED screen and finally define the minimal viewing distance. For different models this distance is from 5-10 m for alphanumerical data and from 10-22 m for video data. The maximal viewing distance depends on total geometry of the panel and sizes of data elements of the image. Power demand Each module in the panel of LED-Wall line has highly reliable inbuilt energy supply of our own make with power factor corrector, which achieves, along with sine-wave input current, wide range of supply voltage- 90 volt …264 volt with frequency of 50-60 Hz. The maximal power demand of models is from 700 up to 1250 W/m2, the medium power demand is from 350 up to W/m2. The using of one red light-emitting diode of the company Agilent (more than twice as bright as LED Nichia, with the same current drain), enables to make less energy-consuming LED screens. Weight Weight of the module in the panel of LED-Wall line is 6 kg; that enables to make the panel one-man-operated. The unit weight of the panel is 37,5 kg/m2. Durability The operating life of the product depends mainly on the lifetime of LED indicators. Physical features of using light-emitting diodes enable to save the workability in a wide range of temperatures from -30° up to +50° . The LED durability is a time span from the start of production operation till the moment, when the indicators light intensity halves. For products of LED-Wall line this parameter is 50 000 working hours in maximal brightness intensity mode (white field) or in medium brightness intensity mode (video and graphic displaying mode) more than 100 000 working hours. Protection The panel of LED-Wall line is produced by special technology. LED indicators are protected with overhead guards. Fundamental Notions(indicating elements) A light-emitting diode is an elemental semiconducting light source, which contains one or more light-emitting crystals in one package with one light flux forming lens. The more crystals are there in the package, all other conditions being equal, the brighter and deeper the image is, and the price is higher. Color light-emitting diode contains in one package red, green and blue crystals together; that enables to produce white color and full range of colors through crystal mixing. Basic parameters of diodes are light intensity and viewing angle at half emissive power. Due to use of light-emitting diodes with various light intensity and various viewing angle there are LED screens of different functions and therefore of different prices. Pixel Elemental dot (chromatic or monochrome) of image pattern. LED screen resolution, that is the capability to display fine details, is measured by the number of pixels vertical and horizontal. So, for example, the resolution of computer format CGA is 320 x 320 pixels. Each pixel consists of one or more light-emitting elements - light-emitting diodes. A module is a complete display unit, which displays graphic-, video- and alphanumerical data. Each module is packaged with independent power supply and primary control elements. The module is a basic element for building of a big-size LED screen. |
| Copyright © 2009 Shanghai UPORO Technology Co., Ltd. . All Rights Reserved. Tel:021-68070295 Fax:021-68070295 Add:5th floor,8 building,No.111, Kangqiao East Road, Pudong, SH 沪ICP备19035376号 |
