TechWeb Encyclopedia


Candela: A unit of measurement of light intensity of light. An ordinary wax candle generates one candela. More precisely, candela is the luminous intensity of a monochromatic source which has a frequency of 540x1012 Hz. A typical LED bulb's brightness is measured in millicandela or mcd, while a LED display's brightness is measured in NIT.


Full Matrix: Capability that permits electronic LED signs to display text, graphics, and animation.
InfoMax: Grandwell's product line of LED displays that are capable of graphics, animations, and variable font sizes. InfoView: Grandwell's product line of LED signs that are designed just for text messages.


LED: An acronym that stands for Light Emitting Diode. Best described as a miniature light bulb smaller than the size of a dime. On average, these diodes have a life expectancy of 50,000 hours or 11.5 years of continuous use, thereby, making them more economical than the standard incandescent light bulb. More information about the features, performance, and cost comparison between LED and incandescent light bulb are avialable.
NIT: A measurement of luminance used primarily to indicate a LED display's brightness. One NIT is equal to one candela per square meter (1cd/m2).
NTSC: (National TV Standard Committee). A standard developed for color TV that is used world wide and supported by Grandwell in conjunction with our LED video boards. NTSC broadcasts 30 interlaced frames per second (60 half frames per second).


Pixel: A single dot of light. A pixel can be composed of either a single LED or a cluster of LEDs. Pixel size can vary. A large pixel size will give you better fill with the electronic message center. The image to the left represents how a 7Hx5W pixel matrix is composed of pixels that are made from a cluster of 7 LEDs.
Diagram of Pitch, space between two pixels.Pitch: The distance from the center of a pixel to the center of the next pixel. Pitch influences the resolution of a LED display that shows images. A small pitch translate to higher resolution. A large pitch translates to larger text/character sizes. The picture to the right indicates how pitch is measured.
RF: An acronym for Radio Frequency. RF is frequently used for wireless communication.
RGB: Red, Green, and Blue. These three colors combined can produce the full spectrum of color. In comparison, blue LED is more expensive than red, green, or amber LEDs. Pure white LED are scares in quantity and by far is the most expensive.
TCP/IP: (Transmission Control Protocol/Internet Protocol) A popular communication protocol used worldwide, specifically with connecting computers together and to the Internet.


VGA: (Video Graphics Array) A common standard for PC video displays. Grandwell's LED video boards support this standard by displaying the contents on a computer screen onto the video board. For more information about various PC display modes, consult the following link.
Video Board: Also known as "Jumbotrons" and commonly found in sports stadiums, casinos, and NY Time Square. Video boards are sophisticated state-of-the-art digital displays that vary in size and resolution. More importantly, video boards need to maintain an aspect ratio for its size. The most common aspect ration is 3:4 and 6:9 (height by width). In order, to obtain good picture quality and resolution, a video board should have at least 112 pixels in height.
VideoMax: Grandwell's line of full color video boards.
Viewing Criteria: The distance, angle, and time that a person can adequately view and understand a sign's content. Diagram and chart of viewing distance and time are available.