Lightguide display
Encyclopedia
A Lightguide display is an obsolete electronic mechanism which was used for displaying alphanumeric characters in electronic devices such as calculator
s, multimeter
s, laboratory measurement instruments
, and entertainment machines such as pinball
games.
s (LED) in the 1970s, though lightguide tubes are still used in electronics manufacturing, in situations where it is difficult to place an LED in the appropriate physical location on a display or bezel. In such cases, LEDs mounted on printed circuit board
s are fitted with lightguides to channel light to the appropriate position. This employs the same principle used in optical fiber
s.
Calculator
An electronic calculator is a small, portable, usually inexpensive electronic device used to perform the basic operations of arithmetic. Modern calculators are more portable than most computers, though most PDAs are comparable in size to handheld calculators.The first solid-state electronic...
s, multimeter
Multimeter
A multimeter or a multitester, also known as a VOM , is an electronic measuring instrument that combines several measurement functions in one unit. A typical multimeter may include features such as the ability to measure voltage, current and resistance...
s, laboratory measurement instruments
Laboratory equipment
Laboratory equipment refers to the various tools and equipment used by scientists working in a laboratory. These include tools such as Bunsen burners, and microscopes as well as speciality equipment such as operant conditioning chambers, spectrophotometers and calorimeters...
, and entertainment machines such as pinball
Pinball
Pinball is a type of arcade game, usually coin-operated, where a player attempts to score points by manipulating one or more metal balls on a playfield inside a glass-covered case called a pinball machine. The primary objective of the game is to score as many points as possible...
games.
Construction
It contains a set of sandwiched acrylic or clear plastic panels, each of which is engraved with a numeral or character to be displayed. Light from independently controlled incandescent bulbs passing into the edge of these panels reflects off the internal surfaces of the plastic. When the light encounters the engraved digits, it is scattered, rendering a brightly illuminated digit or character.Current use
The technology was rendered obsolete by the development of light-emitting diodeLight-emitting diode
A light-emitting diode is a semiconductor light source. LEDs are used as indicator lamps in many devices and are increasingly used for other lighting...
s (LED) in the 1970s, though lightguide tubes are still used in electronics manufacturing, in situations where it is difficult to place an LED in the appropriate physical location on a display or bezel. In such cases, LEDs mounted on printed circuit board
Printed circuit board
A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board or etched wiring...
s are fitted with lightguides to channel light to the appropriate position. This employs the same principle used in optical fiber
Optical fiber
An optical fiber is a flexible, transparent fiber made of a pure glass not much wider than a human hair. It functions as a waveguide, or "light pipe", to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of...
s.