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A Lightguide display (also known as an edge-lit display) is an obsolete electronic mechanism which was used for displaying alphanumeric characters in electronic devices such as calculators, multimeters, laboratory measurement instruments, and entertainment machines such as pinball games.
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 engraved digits, it is scattered, rendering a brightly illuminated digit or character.
The principle of edge-lighting was discovered early and used for commercial signs. U.S. patent 1,139,723 for an "Electric edge lit sign" was filed on July 31, 1914, and granted in 1915. [1] Other similar patents ( 1,707,965 , 1,741,748 , 2,082,724 , 2,623,313 ) for illuminated signs were filed 1928-1948. [1] But the need for digit read-out arose with electronic computers in the 1950s with many independent inventions, both in edge-lighting, nixie tubes and other technologies.
U.S. patent 2,751,584 for an edge-lit multi-layer digit "Visual readout device" was filed on November 10, 1953, by inventor Carl L. Isborn of Hawthorne, California, for the National Cash Register Company and granted on June 19, 1956. [1]
For a similar invention of a "Visual in-line multi-symbol signal indicator", U.S. patent 2,766,447 was filed on July 7, 1954, by Wesley E. Woodson, Jr., El Cajon, and Jack I. Morgan of San Diego, California, and granted on October 9, 1956. [1]
U.S. patent 2,813,266 for an "Indicator device and means for mounting" was filed on January 9, 1956, by Andrew F. Kay, Covert B. Meredith, and Leonard M. Scholl of San Diego County, California, and granted on November 12, 1957. [1] This patent describes a display of five digits next to each other, whereas the earlier two describe just a single digit.
The technology was rendered obsolete by the development of light-emitting diodes (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 boards are fitted with lightguides to channel light to the appropriate position. This employs the same principle used in optical fibers.
An electronic calculator is typically a portable electronic device used to perform calculations, ranging from basic arithmetic to complex mathematics.
A Nixie tube, or cold cathode display, is an electronic device used for displaying numerals or other information using glow discharge.
A cold cathode is a cathode that is not electrically heated by a filament. A cathode may be considered "cold" if it emits more electrons than can be supplied by thermionic emission alone. It is used in gas-discharge lamps, such as neon lamps, discharge tubes, and some types of vacuum tube. The other type of cathode is a hot cathode, which is heated by electric current passing through a filament. A cold cathode does not necessarily operate at a low temperature: it is often heated to its operating temperature by other methods, such as the current passing from the cathode into the gas.
The ANITA Mark VII and ANITA Mark VIII calculators were launched simultaneously in late 1961 as the world's first all-electronic desktop calculators. Designed and built by the Bell Punch Co. in Britain, and marketed through its Sumlock Comptometer division, they used vacuum tubes and cold-cathode switching tubes in their logic circuits and nixie tubes for their numerical displays.
A neon lamp is a miniature gas-discharge lamp. The lamp typically consists of a small glass capsule that contains a mixture of neon and other gases at a low pressure and two electrodes. When sufficient voltage is applied and sufficient current is supplied between the electrodes, the lamp produces an orange glow discharge. The glowing portion in the lamp is a thin region near the cathode; the larger and much longer neon signs are also glow discharges, but they use the positive column which is not present in the ordinary neon lamp. Neon glow lamps were widely used as indicator lamps in the displays of electronic instruments and appliances. They are still sometimes used for their electrical simplicity in high-voltage circuits.
A vacuum fluorescent display (VFD) is a display device once commonly used on consumer electronics equipment such as video cassette recorders, car radios, and microwave ovens.
A seven-segment display is a form of electronic display device for displaying decimal numerals that is an alternative to the more complex dot matrix displays.
Daniel McFarlan Moore was a U.S. electrical engineer and inventor. He developed a novel light source, the "Moore lamp", and a business that produced them in the early 1900s. The Moore lamp was the first commercially viable light-source based on gas discharges instead of incandescence; it was the predecessor to contemporary neon lighting and fluorescent lighting. In his later career Moore developed a miniature neon lamp that was extensively used in electronic displays, as well as vacuum tubes that were used in early television systems.
A backlight is a form of illumination used in liquid-crystal displays (LCDs) that provides illumination from the back or side of a display panel. LCDs do not produce light by themselves, so they need illumination to produce a visible image. Backlights are often used in smartphones, computer monitors, and LCD televisions. They are used in small displays to increase readability in low light conditions such as in wristwatches. Typical sources of light for backlights include light-emitting diodes (LEDs) and cold cathode fluorescent lamps (CCFLs).
An electronic component is any basic discrete electronic device or physical entity part of an electronic system used to affect electrons or their associated fields. Electronic components are mostly industrial products, available in a singular form and are not to be confused with electrical elements, which are conceptual abstractions representing idealized electronic components and elements. A datasheet for an electronic component is a technical document that provides detailed information about the component's specifications, characteristics, and performance.
Neon lighting consists of brightly glowing, electrified glass tubes or bulbs that contain rarefied neon or other gases. Neon lights are a type of cold cathode gas-discharge light. A neon tube is a sealed glass tube with a metal electrode at each end, filled with one of a number of gases at low pressure. A high potential of several thousand volts applied to the electrodes ionizes the gas in the tube, causing it to emit colored light. The color of the light depends on the gas in the tube. Neon lights were named for neon, a noble gas which gives off a popular orange light, but other gases and chemicals called phosphors are used to produce other colors, such as hydrogen (purple-red), helium, carbon dioxide (white), and mercury (blue). Neon tubes can be fabricated in curving artistic shapes, to form letters or pictures. They are mainly used to make dramatic, multicolored glowing signage for advertising, called neon signs, which were popular from the 1920s to 1960s and again in the 1980s.
Light tubes are structures that transmit or distribute natural or artificial light for the purpose of illumination and are examples of optical waveguides.
Electrically operated display devices have developed from electromechanical systems for display of text, up to all-electronic devices capable of full-motion 3D color graphic displays. Electromagnetic devices, using a solenoid coil to control a visible flag or flap, were the earliest type, and were used for text displays such as stock market prices and arrival/departure display times. The cathode ray tube was the workhorse of text and video display technology for several decades until being displaced by plasma, liquid crystal (LCD), and solid-state devices such as thin-film transistors (TFTs), LEDs and OLEDs. With the advent of metal–oxide–semiconductor field-effect transistors (MOSFETs), integrated circuit (IC) chips, microprocessors, and microelectronic devices, many more individual picture elements ("pixels") could be incorporated into one display device, allowing graphic displays and video.
A text display is an electronic alphanumeric display device that is mainly or only capable of showing text, or extremely limited graphic characters. This includes electromechanical split-flap displays, vane displays, and flip-disc displays; all-electronic liquid-crystal displays, incandescent eggcrate displays, LED displays, and vacuum fluorescent displays; and even electric nixie tubes.
A red dot sight is a common classification for a non-magnifying reflector sight that provides an illuminated red dot to the user as a point of aim. A standard design uses a red light-emitting diode (LED) at the focus of collimating optics, which generates a dot-style illuminated reticle that stays in alignment with the firearm the sight is attached to, regardless of eye position.
A reflector sight or reflex sight is an optical sight that allows the user to look through a partially reflecting glass element and see an illuminated projection of an aiming point or some other image superimposed on the field of view. These sights work on the simple optical principle that anything at the focus of a lens or curved mirror will appear to be sitting in front of the viewer at infinity. Reflector sights employ some form of "reflector" to allow the viewer to see the infinity image and the field of view at the same time, either by bouncing the image created by lens off a slanted glass plate, or by using a mostly clear curved glass reflector that images the reticle while the viewer looks through the reflector. Since the reticle is at infinity it stays in alignment with the device to which the sight is attached regardless of the viewer's eye position, removing most of the parallax and other sighting errors found in simple sighting devices.
The following timeline tables list the discoveries and inventions in the history of electrical and electronic engineering.
James Robert Biard was an American electrical engineer and inventor who held 73 U.S. patents. Some of his more significant patents include the first infrared light-emitting diode (LED), the optical isolator, Schottky clamped logic circuits, silicon Metal Oxide Semiconductor Read Only Memory, a low bulk leakage current avalanche photodetector, and fiber-optic data links. In 1980, Biard became a member of the staff of Texas A&M University as an Adjunct Professor of Electrical Engineering. In 1991, he was elected as a member into the National Academy of Engineering for contributions to semiconductor light-emitting diodes and lasers, Schotky-clamped logic, and read-only memories.
Industrial Electronic Engineers, Inc. is an American electronics company based in Van Nuys, California. Founded by Donald Gumpertz in 1946, the company is best known for its electronic displays, becoming a pioneer in the field under Gumpertz's leadership.