1.
Nixie tube
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A Nixie tube, or cold cathode display, is an electronic device for displaying numerals or other information using glow discharge. The glass tube contains a wire-mesh anode and multiple cathodes, shaped like numerals or other symbols, applying power to one cathode surrounds it with an orange glow discharge. The tube is filled with a gas at low pressure, usually mostly neon and often a little mercury or argon, although it resembles a vacuum tube in appearance, its operation does not depend on thermionic emission of electrons from a heated cathode. It is therefore called a tube, or a variant of neon lamp. Such tubes rarely exceed 40 °C even under the most severe of operating conditions in a room at ambient temperature, the early Nixie displays were made by a small vacuum tube manufacturer called Haydu Brothers Laboratories, and introduced in 1955 by Burroughs Corporation, who purchased Haydu. The name Nixie was derived by Burroughs from NIX I, an abbreviation of Numeric Indicator eXperimental No,1, although this may have been a backronym designed to evoke a mythical creature. Hundreds of variations of design were manufactured by many firms. The Burroughs Corporation introduced Nixie and owned the name Nixie as a trademark, nixie-like displays made by other firms had trademarked names including Digitron, Inditron and Numicator. A proper generic term is cold cathode neon readout tube, though the phrase Nixie tube quickly entered the vernacular as a generic name, Burroughs even had another Haydu tube that could operate as a digital counter and directly drive a Nixie tube for display. This was called a Trochotron, in later form known as the Beam-X Switch counter tube, another name was magnetron beam-switching tube, trochotrons were used in the UNIVAC1101 computer, as well as in clocks and frequency counters. The first trochotrons were surrounded by a cylindrical magnet, with poles at the ends. The field inside the magnet had essentially-parallel lines of force, parallel to the axis of the tube and it was a thermionic vacuum tube, inside were a central cathode, ten anodes, and ten spade electrodes. The magnetic field and voltages applied to the made the electrons form a thick sheet that went to only one anode. Applying a pulse with specified width and voltages to the made the sheet advance to the next anode. A later form of trochotron called a Beam-X Switch replaced the large, glow-transfer counting tubes, similar in essential function to the trochotrons, had a glow discharge on one of a number of main cathodes, visible through the top of the glass envelope. Sets of guide cathodes between the indicating cathodes moved the glow in steps to the main cathode. Types with two or three sets of guide cathodes could count in either direction, a well-known trade name for glow-transfer counter tubes in the United Kingdom was Dekatron. Types with connections to each individual indicating cathode, which enabled presetting the tubes state to any value, were trade named Selectron tubes, however, their construction was cruder, their average lifetime was shorter, and they failed to find many applications due to their complex periphery
2.
LED
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A light-emitting diode is a two-lead semiconductor light source. It is a p–n junction diode, which emits light when activated, when a suitable voltage is applied to the leads, electrons are able to recombine with electron holes within the device, releasing energy in the form of photons. This effect is called electroluminescence, and the color of the light is determined by the band gap of the semiconductor. LEDs are typically small and integrated optical components may be used to shape the radiation pattern, appearing as practical electronic components in 1962, the earliest LEDs emitted low-intensity infrared light. Infrared LEDs are still used as transmitting elements in remote-control circuits. The first visible-light LEDs were also of low intensity and limited to red, modern LEDs are available across the visible, ultraviolet, and infrared wavelengths, with very high brightness. Early LEDs were often used as indicator lamps for electronic devices and they were soon packaged into numeric readouts in the form of seven-segment displays and were commonly seen in digital clocks. Recent developments in LEDs permit them to be used in environmental, LEDs have allowed new displays and sensors to be developed, while their high switching rates are also used in advanced communications technology. LEDs have many advantages over incandescent light sources including lower energy consumption, longer lifetime, improved physical robustness, smaller size, and faster switching. Light-emitting diodes are now used in applications as diverse as aviation lighting, automotive headlamps, advertising, general lighting, traffic signals, camera flashes, as of 2017, LED lights home room lighting are as cheap or cheaper than compact fluorescent lamp sources of comparable output. They are also more energy efficient and, arguably, have fewer environmental concerns linked to their disposal. Electroluminescence as a phenomenon was discovered in 1907 by the British experimenter H. J. Round of Marconi Labs, using a crystal of silicon carbide, russian inventor Oleg Losev reported creation of the first LED in 1927. His research was distributed in Soviet, German and British scientific journals, rubin Braunstein of the Radio Corporation of America reported on infrared emission from gallium arsenide and other semiconductor alloys in 1955. Braunstein observed infrared emission generated by simple diode structures using gallium antimonide, GaAs, indium phosphide, in 1957, Braunstein further demonstrated that the rudimentary devices could be used for non-radio communication across a short distance. As noted by Kroemer Braunstein …had set up a simple optical communications link, the emitted light was detected by a PbS diode some distance away. This signal was fed into an amplifier and played back by a loudspeaker. Intercepting the beam stopped the music and we had a great deal of fun playing with this setup. This setup presaged the use of LEDs for optical communication applications, by October 1961, they had demonstrated efficient light emission and signal coupling between a GaAs p-n junction light emitter and an electrically-isolated semiconductor photodetector
3.
Vacuum fluorescent display
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A vacuum fluorescent display is a display device used commonly on consumer-electronics equipment such as video cassette recorders, car radios, and microwave ovens. Sometimes named as ice tube indicator, a VFD operates on the principle of cathodoluminescence, roughly similar to a cathode ray tube, but operating at much lower voltages. Each tube in a VFD has a phosphor coated anode that is bombarded by electrons emitted from the cathode filament, in fact, each tube in VFD is a triode vacuum tube because it also has a mesh control grid. Unlike liquid crystal displays, a VFD emits a bright light with high contrast. Cadmium was commonly used in VFDs in the past, but the current RoHS-compliant VFDs have eliminated this metal from their construction, VFDs can display seven-segment numerals, multi-segment alpha-numeric characters or can be made in a dot-matrix to display different alphanumeric characters and symbols. In practice, there is little limit to the shape of the image that can be displayed, the first VFD was the single indication DM160 by Philips in 1959. The first multi-segment VFD was the 1962 Japanese single-digit, seven-segment device, the displays became common on calculators and other consumer electronics devices. In the late 1980s hundreds of millions of units were made yearly, the device consists of a hot cathode, anodes and grids encased in a glass envelope under a high vacuum condition. The cathode is made up of fine wires, coated by alkaline earth metal oxides. These electrons are controlled and diffused by the grids, which are made up of thin metal, if electrons impinge on the phosphor-coated plates, they fluoresce, emitting light. Unlike the orange-glowing cathodes of traditional vacuum tubes, VFD cathodes are efficient emitters at much lower temperatures, the principle of operation is identical to that of a vacuum tube triode. Electrons can only reach a given plate element if both the grid and the plate are at a potential with respect to the cathode. This allows the displays to be organized as multiplexed displays where the grids and plates form a matrix. In the example of the VCR display shown to the right, all of the similar plates in all of the digits are connected in parallel. One by one, the microprocessor driving the display enables a digit by placing a positive voltage on that digits grid, electrons flow through that digits grid and strike those plates that are at a positive potential. The microprocessor cycles through illuminating the digits in this way at a high enough to create the illusion of all digits glowing at once via persistence of vision. Several amateurs have experimented with the possibilities of using VFDs as triodes, the extra indicators are arranged as if they were segments of an additional digit or two or extra segments of existing digits and are scanned using the same multiplexed strategy as the real digits. Some of these extra indicators may use a phosphor that emits a different colour of light, for example, orange
4.
Output device
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An output device is any piece of computer hardware item which utilizes whatever data and commands from your computer in order to perform a task. This leads to the results of data processing carried out by a processing system which converts the electronically generated information into human-readable form. A display device is a device that visually conveys text, graphics. Information shown on a device is called soft copy because the information exists electronically and is displayed for a temporary period of time. Display devices include CRT monitors, LCD monitors and displays, gas plasma monitors, there are many input and output devices such as multi function printers and computer-based navigation systems that are used for specialized or unique applications. In computing, input/output refers to the communication between an information processing system, and the outside world, inputs are the signals or data received by the system, and outputs are the signals or data sent from it. Some types of output are text, graphics, tactile, audio, text consists of characters that are used to create words, sentences, and paragraphs. Graphics are digital representations of information such as drawings, charts, photographs. Tactile output such as raised line drawings may be useful for individuals who are blind. Audio is music, speech, or any other sound, video consists of images played back at speeds to provide the appearance of full motion. A digital image is a representation of an image stored on a computer. They dont have any size until they are displayed on a screen or printed on paper. Until that point, they are just a collection of numbers on the hard drive that describe the individual elements of a picture. Some computers come with graphics capability of. Others need a device, called a card or graphics adapter board. Unless a computer has graphics capability built into the motherboard, that takes place on the graphics card. Depending on whether the resolution is fixed, it may be of vector or raster type. Without qualifications, the digital image usually refers to raster images also called bitmap images
5.
Information
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In other words, it is the answer to a question of some kind. It is thus related to data and knowledge, as data represents values attributed to parameters, as it regards data, the informations existence is not necessarily coupled to an observer, while in the case of knowledge, the information requires a cognitive observer. At its most fundamental, information is any propagation of cause, Information can be encoded into various forms for transmission and interpretation. It can also be encrypted for safe storage and communication, the uncertainty of an event is measured by its probability of occurrence and is inversely proportional to that. The more uncertain an event, the information is required to resolve uncertainty of that event. The bit is a unit of information, but other units such as the nat may be used. Example, information in one fair coin flip, log2 =1 bit, the concept that information is the message has different meanings in different contexts. The English word was derived from the Latin stem of the nominative. Inform itself comes from the Latin verb informare, which means to give form, eidos can also be associated with thought, proposition, or even concept. The ancient Greek word for information is πληροφορία, which transliterates from πλήρης fully and it literally means fully bears or conveys fully. In modern Greek language the word Πληροφορία is still in use and has the same meaning as the word information in English. In addition to its meaning, the word Πληροφορία as a symbol has deep roots in Aristotles semiotic triangle. In this regard it can be interpreted to communicate information to the one decoding that specific type of sign, from the stance of information theory, information is taken as an ordered sequence of symbols from an alphabet, say an input alphabet χ, and an output alphabet ϒ. Information processing consists of a function that maps any input sequence from χ into an output sequence from ϒ. The mapping may be probabilistic or deterministic and it may have memory or be memoryless. Often information can be viewed as a type of input to an organism or system, inputs are of two kinds, some inputs are important to the function of the organism or system by themselves. In his book Sensory Ecology Dusenbery called these causal inputs, other inputs are important only because they are associated with causal inputs and can be used to predict the occurrence of a causal input at a later time. Some information is important because of association with information but eventually there must be a connection to a causal input
6.
Visual system
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The visual system is the part of the central nervous system which gives organisms the ability to process visual detail, as well as enabling the formation of several non-image photo response functions. It detects and interprets information from visible light to build a representation of the surrounding environment, the psychological process of visual information is known as visual perception, a lack of which is called blindness. Non-image forming visual functions, independent of perception, include the pupillary light reflex. This article mostly describes the system of mammals, humans in particular. Together the cornea and lens refract light into a small image, the retina transcribes this image into electrical pulses using rods and cones. The optic nerve then carries these pulses through the optic canal, upon reaching the optic chiasm the nerve fibers decussate. The fibers then branch and terminate in three places, most end in the lateral geniculate nucleus. Before the LGN forwards the pulses to V1 of the visual cortex it gauges the range of objects, the LGN also sends some fibers to V2 and V3. V1 performs edge-detection to understand spatial organization, V2 both forwards pulses to V1 and receives them. Pulvinar is responsible for saccade and visual attention, V2 serves much the same function as V1, however, it also handles illusory contours, determining depth by comparing left and right pulses, and foreground distinguishment. V3 helps process ‘global motion’ of objects, V3 connects to V1, V2, and the inferior temporal cortex. V4 recognizes simple shapes, gets input from V1, V2, V3, LGN, v5’s outputs include V4 and its surrounding area, and eye-movement motor cortices. V5’s functionality is similar to that of the other V’s, however, V6 works in conjunction with V5 on motion analysis. V5 analyzes self-motion, whereas V6 analyzes motion of objects relative to the background, v6’s primary input is V1, with V5 additions. V6 houses the topographical map for vision, V6 outputs to the region directly around it. V6A has direct connections to arm-moving cortices, including the premotor cortex, the inferior temporal gyrus recognizes complex shapes, objects, and faces or, in conjunction with the hippocampus, creates new memories. The pretectal area is seven unique nuclei, anterior, posterior and medial pretectal nuclei inhibit pain, aid in REM, and aid the accommodation reflex, respectively. The Edinger-Westphal nucleus moderates pupil dilation and aids in convergence of the eyes, nuclei of the optic tract are involved in smooth pursuit eye movement and the accommodation reflex, as well as REM
7.
Somatosensory system
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The somatosensory system is a part of the sensory nervous system. The somatosensory system is a system of sensory neurons and pathways that responds to changes at the surface or inside the body. The axons, of sensory neurons connect with, or respond to, sensory receptors are found all over the body including the skin, epithelial tissues, muscles, bones and joints, internal organs, and the cardiovascular system. Somatic senses are sometimes referred to as somesthetic senses, with the understanding that somesthesis includes the sense of touch, proprioception, the mapping of the body surfaces in the brain is called a cortical homunculus and plays a fundamental role in the creation of body image. This brain-surface map is not immutable, however, dramatic shifts can occur in response to stroke or injury. The four mechanoreceptors in the skin respond to different stimuli for short or long periods. Merkel cell nerve endings are found in the epidermis and hair follicles, they react to low vibrations. Due to a receptive field they are used in areas like fingertips the most, they are not covered. Tactile corpuscles react to moderate vibration and light touch and they are located in the dermal papillae, due to their reactivity they are primarily located in fingertips and lips. They respond in quick action potentials, unlike Merkel and they are responsible for the ability to read Braille and feel gentle stimuli. Lamellar corpuscles determine gross touch and distinguish rough and soft substances and they react in quick action potentials, especially to vibrations around 250 Hz. They are the most sensitive to vibrations, and have large receptor fields, pacinian reacts only to sudden stimuli so pressures like clothes that are always compressing their shape are quickly ignored. Bulbous corpuscles react slowly and respond to sustained skin stretch and they are responsible for the feeling of object slippage and play a major role in the kinesthetic sense and control of finger position and movement. Merkel and bulbous cells are myelinated, the rest are not, all of these receptors are activated upon pressures that squish their shape causing an action potential. All afferent touch/vibration info ascends the spinal cord via the posterior column-medial lemniscus pathway via gracilis or cuneatus, cuneatus sends signals to the cochlear nucleus indirectly via spinal grey matter, this info is used in determining if a perceived sound is just villi noise/irritation. All fibers cross in the medulla, the postcentral gyrus includes the primary somatosensory cortex collectively referred to as S1. BA3 receives the densest projections from the thalamus, bA3a is involved with the sense of relative position of neighboring body parts and amount of effort being used during movement. BA3b is responsible for distributing somato info, it projects texture info to BA1, region S2 divides into Area S2 and parietal ventral area
8.
Refreshable braille display
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A refreshable braille display or braille terminal is an electro-mechanical device for displaying braille characters, usually by means of round-tipped pins raised through holes in a flat surface. Blind computer users who use a computer monitor can use it to read text output. Speech synthesizers are also used for the same task. Deafblind computer users may also use refreshable braille displays, the base of a refreshable braille display often integrates a pure braille keyboard. Other variants exist that use a conventional QWERTY keyboard for input and braille pins for output, on some models the position of the cursor is represented by vibrating the dots, and some models have a switch associated with each cell to move the cursor to that cell directly. The mechanism which raises the dots uses the effect of some crystals. Such a crystal is connected to a lever, which in turn raises the dot, there has to be a crystal for each dot of the display, i. e. eight per character. Because of the complexity of producing a reliable display that will cope with daily wear and tear, usually, only 40 or 80 braille cells are displayed. Models with between 18 and 40 cells exist in some notetaker devices, the software that controls the display is called a screen reader. It gathers the content of the screen from the system, converts it into braille characters. Screen readers for graphical operating systems are complex, because graphical elements like windows or slidebars have to be interpreted and described in text form. A rotating-wheel Braille display was developed in 2000 by the National Institute of Standards and Technology, both wheels are still in the process of commercialization. In these units, braille dots are put on the edge of a spinning wheel, the braille dots are set in a simple scanning-style fashion as the dots on the wheel spin past a stationary actuator that sets the braille characters. As a result, manufacturing complexity is reduced and rotating-wheel braille displays. Designs for a full braille computer monitor have been patented but not yet produced, a full page braille display with 1,000 cells was developed in 2015 by the Tactisplay Corp. With total 12,000 pixels configured in 120*100, it can show any BANA compatible braille graphic page in 8 seconds and this video shows operation of the device. Tactile is a real-time text-to-braille translation device currently under development at the Massachusetts Institute of Technology, GNOME accessibility NIST, Converting Digital Information to Braille at the Wayback Machine Information on Bi-directional Refreshable Tactile Display US Patent 6,692,255
9.
Television
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Television or TV is a telecommunication medium used for transmitting moving images in monochrome, or in color, and in two or three dimensions and sound. The term can refer to a set, a television program. Television is a medium for entertainment, education, news, politics, gossip. Television became available in experimental forms in the late 1920s. After World War II, a form of black-and-white TV broadcasting became popular in the United States and Britain, and television sets became commonplace in homes, businesses. During the 1950s, television was the medium for influencing public opinion. In the mid-1960s, color broadcasting was introduced in the US, for many reasons, the storage of television and video programming now occurs on the cloud. At the end of the first decade of the 2000s, digital television transmissions greatly increased in popularity, another development was the move from standard-definition television to high-definition television, which provides a resolution that is substantially higher. HDTV may be transmitted in various formats, 1080p, 1080i, in 2013, 79% of the worlds households owned a television set. Most TV sets sold in the 2000s were flat-panel, mainly LEDs, major manufacturers announced the discontinuation of CRT, DLP, plasma, and even fluorescent-backlit LCDs by the mid-2010s. In the near future, LEDs are gradually expected to be replaced by OLEDs, also, major manufacturers have announced that they will increasingly produce smart TVs in the mid-2010s. Smart TVs with integrated Internet and Web 2.0 functions became the dominant form of television by the late 2010s, Television signals were initially distributed only as terrestrial television using high-powered radio-frequency transmitters to broadcast the signal to individual television receivers. Alternatively television signals are distributed by cable or optical fiber, satellite systems and. Until the early 2000s, these were transmitted as analog signals, a standard television set is composed of multiple internal electronic circuits, including a tuner for receiving and decoding broadcast signals. A visual display device which lacks a tuner is correctly called a video monitor rather than a television, the word television comes from Ancient Greek τῆλε, meaning far, and Latin visio, meaning sight. The Anglicised version of the term is first attested in 1907 and it was. formed in English or borrowed from French télévision. In the 19th century and early 20th century, other. proposals for the name of a technology for sending pictures over distance were telephote. The abbreviation TV is from 1948, the use of the term to mean a television set dates from 1941
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