Digital LED displays involve single crystal phosphor materials, which distinguishes them from the polycrystal electroluminescent displays. Light emitting diodes (LED) are PN junction devices that give off light radiation when biased in the forward direction. Most light emitting diodes function in the near infrared and visible ranges, though there are now UV LEDs. Light emitting diodes are a reliable means of indication compared to light sources such as incandescent and neon lamps. LEDs are solid-state devices requiring little power and generating little heat. Because their heat generation is low and because they do not rely on a deteriorating material to generate light, LEDs have long operating lifetimes. One of the alternatives, incandescent bulbs, consumes much more power, generate a great deal of heat, and rely on a filament that deteriorates in use. Neon bulbs, on the other hand, rely on excited plasma, which, along with its electrodes, can deteriorate over time. Digital LED displays are highly versatile and well suited to a variety of measurement applications. Display types can be segmented or dot matrix. A seven-segment display can display numbers only; a sixteen-segment display can display numbers and letters. A 4x7 dot matrix display can display numbers only; a 5x7 dot matrix display can display numbers and letters. Digital LED displays can be numeric or alpha numeric. Numeric displays display numbers only, a seven-segment display or 4x7 dot matrix display. An alphanumeric display can display numbers and letters, a sixteen-segment display or 5x7 dot matrix display.
Digital LED displays can have a common anode or common cathode configuration. In a common anode configuration all the segments in the LED share one anode pin. In a common cathode configuration all the segments in the LED share one cathode pin. Common cathode is the "standard" circuit where the cathode is connected to the "common" point on the circuit, usually ground, and usually through a resistor, which is often bypassed with a capacitor, placing it at "AC" ground potential. Important display package specifications to consider when searching for digital LED displays include the number of rows and the number of characters per row. Standard color choices for LEDs include standard red, yellow, high efficiency red, orange, green, and blue. Other display specifications to consider include color wavelength, character height, and viewing distance. Wavelength of the display will be determined by the color of the LED. Viewing distance is determined primarily by the minimum size requirements for objects that the user must see. The viewing angles on the x and y-axis are also important to consider. The viewing angle of the display is the angle, in degrees, between a line normal to the display surface and the user's visual axis. Minimum and typical luminous intensity describes the luminous flux per unit solid angle, and its unit of measurement is the candela (cd). Case dimensions include width depth and height. The case or package of the display will have separate dimensions than the actual viewing area of the display.Read user Insights about Digital LED Displays