LED Display Screen

There are some advantages of LED Display Screen, such as: high brightness, low operating voltage, low power consumption, mini-size, simple driving mode, long life span, shock-proof, steady performance and matching with integrated circuit, moreover, the application is involved in most industry of the social economy, eg. Display information for security exchange, finance, ports, stations, stadiums, roads, etc, and indoor & outdoor advertising. LED Display Screen is a kind of new electronic product in the 80s of the 20thCentury, so the selection and maintenance of the product is new to maintenance staff of household electrical appliances, so we hope to create people’s interests to LED products through the text, especially LED Display Screen.
　　
A.Classification of LED Display Screen
1.There are two kinds of LED Screens according to the work mode: Full-featured LED Display Screen and Intelligent LED Display Screen, and both of them are assembled by the modules with 8X8 dots in international standard(the same surface and basic display function), while the difference is as follows:
It’s unnecessary for intelligent LED Screen to connect with the upper computer, for it can work independently, and there is built-in CPU which could save various images when it’s power off. There is clock chip in some screen, so it could display calendar and time. If we want to modify display contents, just connect the interface of RS232 with the computer. While, full-featured LED Display Screen could not work until it’s connected with one computer.
There are fewer display modes for intelligent LED Screen, such as the popup type, curtain display, rolling type and so on. However, there are various display modes for full-featured LED Screen (if we use professional software for broadcasting).
It’s easy to operate intelligent LED Screen, but some special staff is required to operate and maintain full-featured LED Screen (professional knowledge is required for making animations)
2.There are single-color and full-color LED Display Screen classified according to colors. Single-color modules with 8X8dots are made of single-color LED chips, and red is the common color. Single-color LED screen could display characters, data, and two-dimensional pictures. Indoor single-color LED screen is economic, merely the color is monotonic.
Full-color LED Display Screen is made of standard modules with 8X8dots and two primary colors, and there are one red and one green LED chips in each pixel. When two chips are both lightened, the pixel is yellow, so LED Screen with two primary colors could display three kinds of colors: red, green and yellow, what’s more, it can also display colorized characters, data and animation. Besides, LED Full-color Screen could connect with all kinds of data sets to display realtime dynamic data and advertisement with a better display effect, that is the most popular one at present in the LED market.
Full-color LED Gray-scaled Display Screen consists of many modules with 8X8 dots in two primary colors, and there are three primary colors in every pixel: red, yellow, and green, with 16X16 grayscale which is equivalent to 256X256 or 64k kinds of colors. LED Display Screen could display pictures, images, three-dimensional animation and video images in rich and vivid colors.
3.There are Normal density LED Display Screen and High-density LED Display Screen classified according to the pixel density. The density of LED Display Screen is related to the pixel diameter, smaller pixel diameter but much higher density. More closer viewing distance, more higher density, vice versa. The standard module for indoor use is 8X8 dots, and the general specification is φ5mm and φ3.7mm.
B. Required functions
　 1.The selection to LED Chips is the most important step. Manufacturers of Medium-high-grade LED Chips include ++Nichia Co., Toyota, Hp, Siemens, Cree, some brands made in Taiwan and so on. ++, Cree and Siemens major in pure green and pure blue LED chips, while the manufacturers in Taiwan major in red and green LED chips.
According to the practical use and color assortment of LED Screen with one red and four green LED chips, the red LED chip is made up of red LED chips of four elements, while the green LED chip of three elements. 712SOL red LED chips manufactured in Taiwan are usually used, and 113YGU green LED chips made in Taiwan Dingyuan Co. is one of the most advanced in configuration used for indoor display with two primary colors. Besides, the configuration of two red LED chips and one pure green is used for outdoor dual-color LED Screen.
2.The driving circuit of integrated components accepts the digital signals from computers to drive the PCB, then the characters or pictures are formed, the reliability of which determines whether the luminous components can work well or not. When we see it from the working situation of outdoor LED Screen, the driving circuit gets the highest failure rate which is resulted from the low quality of integrated IC. At present, the universal LED chips 4953 and HC595 are matched for outdoor use, what’s more, special driving LED chips and 595 of 6B series made in America are used for top grade LED Display Screen.
3.The failure rate of the power supply of LED Screen must be controlled less than 1% within 5years, and the quality of power supply is determined by the selection to components and the quality control. There are various brands of power supply in markets, such as Chuanglian, Sida, and Mingwei made in Taiwan, etc. Actually speaking, the brand Sida made in Changzhou is more reliable and the life span is longer.
4.Both the authoring software and the display software are required to supply simple and alternating programming and broadcasting environments, with distributed and modularized design, that is more reliable and extensible.
C. The structure and control mode of LED Graph Display Screen
　　 1.Basic structure LED Graph Display Screen consists of screen, computers, controller, dot matrix display unit and power supply, etc.
　　 a.The screen consists of dot-matrix, driving circuit or any other circuit(it’s determined by the PCB). Dot-matrix display is made up of single or dual-color modules with 8X8 dots, eg. The strip LED Screen with 32X128 dots, consist of 4X16 pcs modules, of which the dot is 8X8.
　　 b.Intelligent display unit: the unit is an independent system or only one part of the LED Graph Display Screen, and it can display characters, lines and simple pictures. The master device adopts single-chip, and communication interface RS-485, Chinese Character Library and display buffer, etc. Every intelligent display unit has its own number or address. In order to satisfy the demand of the size of LED graph display screen, the quantity of intelligent display unit is optional.
　　 c.Master device: It uses single-chip, Chinese Character Library, power-protect data memory, time of day clock and two communication interfaces HS-485, which are all embedded into the system of LED graph screen. One interface of the two communicates with the computer, and the communication distance is hundreds of meters, the other is used to communicate with each intelligent display unit.The main function of the master device: receive the order from computers and display data; transfer the order or data to related intelligent display unit, and to ensure the synchronism of the display.
In practical applications, LED Graph Display Screen is an independent display system which consists of master device and intelligent display unit.　　
d.Computers: the main function of the computer and related software: if change display contents, then transfer the new data to the master device; if change the display mode, transfer related order to the master device; if inline dynamic display is required, transfer realtime data to the master device.
LED Graph Display Screen only displays communication, no grayscale displayed, besides, the data volume is small, and the exchange speed of information is slow, so the asynchronous and serial communication mode is suitable for the data transfer between the upper and the lower computer.
　　 2.Control mode: With the wide application of LED Graph Display Screen, and different circumstances and requirements, various control modes are optional. (1)Group display is suitable for large scale LED Graph Display Screens, and each displays the same content, such as the same market or meeting place, etc. Moreover, in this control mode, one upper computer could connect with multi lower computers (in Figure 2). It’s controlled by the upper computer, and communicates through broadcasting: the upper computer sends signals which is received by the lower computers at the same time.
When LED Graph Display Screen displays different contents, they could be distinguished through numbering the lower computers. The upper computer sends the No. of the lower computers to them before sending data, and the lower computers will judge whether the data is acceptable or not at first as soon as they receive the No., then only the pointed lower computers could receive data, and other ones ignore it, so as to display different contents in different graph screens. (2) In some occasions, the display contents on LED Graph Screen are relatively simple with less frequency through the infrared remote control mode, so the upper computer is unnecessary. Lower computers storage necessary data by themselves, and display content could be chosen according to the situation. Infrared remote control of TV could be changed into remote controller for Graph LED Screen.
(3) Wireless remote control: LED Graph Display Screen is arranged dispersedly, so the distance among screens may be long. Under that circumstance, it’s uneconomic for the communication medium between the upper and the lower computer to be wired, while, the wireless communication is appropriate.
四. Selection of LED Display Screen
The selection of LED Display Screen must satisfy one’s need, moreover the space constraints and the investment are also the key factors. For instance, it’s not only up to the indoor use and outdoor use, but also depends on what it displays: only characters, or both simple pictures and characters, or various video signals, animations, images and characters, besides, both the control mode (synchronization control or asynchronous control or wireless control and so on) and the viewing distance are rather significant to the selection of LED Display Screen.
Generally speaking, dual-color or full-color LED Display Screen in high dot-density is suitable for displaying images which requires close viewing distance, while, the specification in low dot-density is suitable for plenty of characters display. In addition, the color of LED Display Screen is based on the investment, the materials used for outline border based on the decoration states, and the control mode based on the application.
To be specific, more attention should be paid to the selection:
1.Try to select LED Chips in new style with wide viewing angle, and there are some advantages: colors are pure, operation is consistent, and the life span is more than 100,000 hours.
2.The most popular outer-encapsulation to LED Display Screen is required, such as the quadrate barrel with hood, silicone glue sealing, metal-free assembling. It’s exquisite and firm, sun-resistant, dustproof, waterproof, high-temperature resistant and short-circuit-proof output, etc.
3.Try to select suitable LED Display Screens based on different features of products and customers’ actual demand.
(1) LED Display Screen with φ5.0mm is suitable for stations, port, entrance of large-scale supermarkets or elevators, Some advantages are as follows, vivid characters, cheap price and controlled by computer-group.
(2)φ3.75mm Dual-color LED Display Screen is cheap, and suitable for revealing cooperate images and advertising, widely used in banks and marketplace, etc. While, φ5mm Full-color LED Screen could supply much better display effect.
(3)φ5mm dual-color LED Display Screen is suitable for large-scale place, while φ10mm LED Screen is superior in better display effect.
(4)φ3mm &φ5mm LED Display Screen is widely used in service windows of banks, post rooms, and electric-power, to display information at any time when service windows changed.
4.The quality of outdoor LED Display Screen must be superior because of the hostile environment outside, so a lot of factors should be considered.
(1) From the perspective of use, Full-color LED Display Screen will be the main trend in the near future because of Wish you have a very nice weekend. After consideration, I sincerely recommend you use our P12 outdoor full color, which is very popular in USA and European rental market; it has a very good quality and light uniformity as well as completive price, the following parts highlighted in purple for your kind perusal. And also I had attached the pricelist and some installation pic..

1. As known to all, the most characteristic of LED display is energy and electricity saving. Since the basic ingredient of the LED display is its lamp chip, how much the power consumption can be saved is mainly based on the size of each lamp chips. The quotation I offered you is with OPTO brand chip, we strictly control the chip size as: Red lamp chip: 12X12 mil, Green lamp chip 14X14 mil, Blue lamp chip 14X14 mil, bigger than the normal size 12X12mil. Smaller the chip size is, more power consumption the display costs. Because when the LED display with smaller lamp chip required a high brightness, it must increase input electricity to reach up to such brightness. If the display always works with high current for long time, the life time of the display and the lamp would be reduced down rapidly. However, for the consideration of price and cost, many factories would prefer purchasing smaller chip size in order to offer a cheaper quotation.

2. The second way to control the LED display’s power consumption we adapt is brightness adjust system which embedded in the control system and connect outside of the display. Therefore, the user can adjust brightness of LED display manually or automatically in the system to meet the requirement of brightness in day and night. For the driving mode, we adopt Constant-current Drive on the basis of Driving IC of 5026 in TOSHIBA and MBI,

3. We have the highest color level in Chinese LED market, our display can show 65536 shades per color, more over 4096 shades of other companies. This would make your display be attractive by more attention.

4. Cabinets. We use OEM’s products. No doubt for the quality of the material. Also, the design is very special. On one hand it looks more elegant. On another hand, it is very convenient for the user to set up .(4 sets of fast lock system , more handles on 2 sides). The gap between 2 cabinets is less then 0.5mm. and the thickness of the cabinets is 1.5mm.

5. Usually, the life time of the LED display is about 6-8 years. But our company provides customers 2 or 3 years of guarantee time based on the specifications required, which means if any problem happened to any component of the display in 2 years, you could return the components to us and we send you the news. This would increase the LED display’s life time up to 9-10 years.

6. And also, I’d like to introduce our Production & equipment in the following:

◆ 100,000 grade clean production workshop,Test 30,000 grades.
◆ LED tester from TW T650-C
◆ SMT machine,Sanyang3600Z,Yamaha100G,Yamaha100X
◆ Wave-solder machine Ridong350C
◆ Back-fellow solder machine,DongyejitianYL800
◆
7. I’d like to point the PCB board out separately. Our engineers draw and design the PCB board, and them customized from PCB manufactures, not just buying from general market, and use them to our products completely and directly. Nowadays, many manufacturers will use general PCB boards to save money, but it will cause color and light uniformity problems sometimes.