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1、Chapter 1 Project Overview 1.1 INTRODUCTION Visual impact is the most effective mode of influencing human minds which is the main aim of adverstisements etc. A display device serves this purpose.A display device is a device for presentation of information for visual or tactile reception, acquired, s
2、tored, or transmitted in various forms. The display devices used to display information on machines, clocks, railway departure indicators and many other devices require a simple display of limited resolution. The display consists of a matrix of lights or mechanical indicators arranged in a rectangul
3、ar configuration (other shapes are also possible, although not common) such that by switching on or off selected lights, text or graphics can be displayed. Various modifications has been made in the display board.Now LED display panels are widely used throughout the world in all situations to create
4、 images for visual displays in a variety of applications including communication and visual display devices. LED array display board is a popular instrument for commercial usage. Many banks, shops and cinemas are willing to install one piece of it because of its versatility. LED array display board
5、can be very bright and eye-catching. Display signs used for advertising or for displaying direction or other information to motorists have an important feature in common. They should be eye-catching and their information should be easy to absorb. In advertising, a signboard made of an LED display ge
6、nerally standing at a conspicuous location, such as a bustling road, is widely used. The LED display comprises a plurality of LEDs controlled by special hardware and software to perform moving images on a screen thereof to attract the attention of passersby. The LED array display board is used in a
7、bank to show the current stock market value, currency exchange rate and interests rate. It can also be used in a shop to tell people the prices and other commercial information. LED display board serves the above purposes with advantages rendered by LEDs LEDs produce more light per watt than incande
8、scent bulbs; this is useful in battery powered or energy-saving devices. LEDs can emit light of an intended color without the use of color filters that traditional lighting methods require. This is more efficient and can lower initial costs. The solid package of the LED can be designed to focus its
9、light. Incandescent and fluorescent sources often require an external reflector to collect light and direct it in a usable manner. LEDs are ideal for use in applications that are subject to frequent on-off cycling, unlike fluorescent lamps that burn out more quickly when cycled frequently, or HID la
10、mps that require a long time before restarting. LEDs, being solid state components, are difficult to damage with external shock. Fluorescent and incandescent bulbs are easily broken if dropped on the ground. LEDs can have a relatively long useful life. LEDs light up very quickly LEDs can be very sma
11、ll and are easily populated onto printed circuit boards. Organic light emitting diodes (OLED) are a promising technology for flat-panel displays. Owing to high brightness, fast response speed, light weight, thin and small features, full color, no viewing angle differences, no need for an LCD back-li
12、ght board and low electrical consumption, an organic light emitting diode display takes the lead to substitute a twist nomadic (TN), a super twist nomadic (STN) liquid crystal display, or a small-sized thin-film transistor (TFT) LCD display. Light emitting diodes are useful in a wide range of high a
13、nd low resolution display devices.1.2 OBJECTIVE Display technology pervades all aspects of present day life, from televisions to automobile dashboards to laptop computers to digital cameras. Single coloured LED display boards are very common nowadays. The same yellow or red coloured board is not att
14、ractive .The introduction of multicoloured LEDs into the display boards make them attractive. This project is oriented towards the development of a prototype of a multicoloured LED display board which is being controlled by an LED driver. The use of multicolour LED opens door to many applications. T
15、he display board is made on readily available components. The important requirement is that the display board should have long life expectancy, high tolerance to humidity, low power consumption and minimal heat generation. The fundamental part is a 4X4 LED module which could be repeated column wise
16、or row wise to enlarge the display without any change in circuitry. Both single line and double line display could be affected. Motivation towards the project was to make available a readily expandable multicolour display board which can be used for multiple purposes.1.3 SPECIFICATIONS o 4 x 4 multicoloured LED modules (8) o USB interface o High speed response o Power supply requirement :5V ,4AChapter 2
