LED display pixel type?
The basic elements of an LED (light emitting diode) display are the LEDs that make up the pixel. 
The minimum requirement for a pixel to produce a full color image is a Red, Green and Blue diode. There are two types of diode used; Discrete or DIP and Surface Mount (SMD).
The two main differences between these diode types are size and brightness.
Discrete LED's are individually mounted LED's that are larger and brighter than SMD diodes. These types of LED's are therefore predominantly found on outdoor screens where high brightness is required to combat the effects of sunlight. These outdoor screens are normally large and viewed from long distance so medium to low resolution is only required. The diodes are arranged in groups to provide the required brightness and resolution for the display. These groups typically contain 3 diodes in a triangle or 4 in a square. For lower resolutions the group could contain 5 or more diodes to obtain the required brightness levels.
SMD diodes are generally grouped together in a single package containing a red, green and blue diode encapsulated under one lens. As they have a reduced light output they are mainly used for indoor applications. Due to the small size of each diode they are mounted very close together in the package making it look like one single light source capable of producing a full range of color. This also means that high resolution displays can be produced that suit the needs of indoor displays with short viewing distances.
Due to the difference in construction an SMD display with the same resolution as a discrete diode display can be viewed from a closer distance before pixel separation is visible. A rough guide would be that you need to be 25% farther out from a discrete diode screen with the same resolutions as an SMD in order to have a good content view of the layout.
Discrete diode displays have been available for much longer than SMD so you will see these in all applications both outdoor and indoor. SMD displays now dominate the high resolution indoor display market as they can reach much higher resolutions. The technology and performance of SMD diodes is improving so expect to see them used in more applications for medium resolution indoor displays and outdoor and their brightness capability improves.
About Ultravision LED: William Y. Hall is President of the privately owned company based in Addison, Texas with offices in China. Ultravision LED specializes in turnkey LED display integration from the LED display, to installation, service, maintenance and even affordable factory financing. Ultravision LED's technological advancements continue to transcend digital communications systems for wide-reaching industries including sports and entertainment, retail, urban spectaculars and digital advertising companies. Information about Ultravision LED and turnkey integrated solutions for schools, retail and advertising applications can be found at www.ultravisionled.com or by calling 214-260-4500.
