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Monoscope
A monoscope was a special form of video camera tube which displayed a single still video image. The image was built into the tube, hence the name. The tube resembled a small cathode-ray tube (CRT). Monoscopes were used beginning in the 1950s to generate TV test patterns and station logos. This type of test card generation system was technologically obsolete by the 1980s. Design The monoscope was similar in construction to a CRT, with an electron gun at one end and at the other, a metal target screen with an image formed on it. This was in the position where a CRT would have its phosphor-coated display screen. As the electron beam scanned the target, varying numbers of electrons were reflected from the different areas of the image. The reflected electrons were picked up by an internal electrode ring, producing a varying electrical signal which was amplified to become the video output of the tube. This signal reproduced an accurate still image of the target, so the monosco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Test Card
A test card, also known as a test pattern or start-up/closedown test, is a television test signal, typically broadcast at times when the transmitter is active but no program is being broadcast (often at sign-on and sign-off). Used since the earliest TV broadcasts, test cards were originally physical cards at which a television camera was pointed, allowing for simple adjustments of picture quality. Such cards are still often used for calibration, alignment, and matching of cameras and camcorders. From the 1950s, test card images were built into monoscope tubes which freed up the use of TV cameras which would otherwise have to be rotated to continuously broadcast physical test cards during downtime hours. Electronically generated test patterns, used for calibrating or troubleshooting the downstream signal path, were introduced in the late-1960s, and became commonly used from the 1970s and 80s. These are generated by test signal generators, which do not depend on the correct config ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Character Generator
A character generator, often abbreviated as CG, is a device or software that produces static or animated text (such as news crawls and credits rolls) for keying into a video stream. Modern character generators are computer-based, and they can generate graphics as well as text. History Monoscopes were used as character generators for text mode video rendering in computer displays for a short time in the 1960s. The CBS Laboratories Vidiac, and the A. B. Dick Videograph 990 System, were among the earliest character generators for broadcast television. CBS Laboratories later developed the more advanced Vidifont system in preparation for the 1968 US presidential elections, where a rapid method of all-electronic character generation was required so that news outlets could identify unexpected interviewees on the spot. A similar generator using analogue electronics, Anchor, was developed by the BBC in 1970 and used in the general election later that year. Usage In the televisio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indian Head Test Card
The Indian-head test pattern is a test card that gained widespread adoption during the black-and-white television broadcasting era as an aid in the calibration of television equipment. It features a drawing of a Native American wearing a headdress surrounded by numerous graphic elements designed to test different aspects of broadcast display. The card was created by RCA to be the standard image for their TK-1 monoscope, a simple video camera capable of producing only the image embedded within it. The pattern was introduced in 1939 and over the following two decades became a fixture of television broadcast across North America in 525-line resolution and (often in modified form) abroad in 525- and 625-line resolution until it was made obsolete by the rise of color television in the 1960s. Features and use The Indian-head test pattern was created by RCA at their factory in Harrison, New Jersey. Each element of the card was designed to measure a specific technical aspect of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Video Camera Tube
Video camera tubes are devices based on the cathode-ray tube that were used in television cameras to capture television images, prior to the introduction of charge-coupled device (CCD) image sensors in the 1980s. Several different types of tubes were in use from the early 1930s, and as late as the 1990s. In these tubes, an cathode ray, electron beam is scanned across an image of the scene to be broadcast focused on a target. This generated a current that is dependent on the brightness of the image on the target at the scan point. The size of the striking ray is tiny compared to the size of the target, allowing 480–486 horizontal scan lines per image in the NTSC format, 576 lines in PAL, and as many as 1035 lines in Multiple sub-Nyquist sampling encoding, Hi-Vision. Cathode-ray tube Any vacuum tube which operates using a focused beam of electrons, originally called cathode rays, is known as a cathode-ray tube (CRT). These are usually seen as display devices as used in older (i. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RCA Indian Head Test Pattern
RCA Corporation was a major American electronics company, which was founded in 1919 as the Radio Corporation of America. It was initially a patent pool, patent trust owned by General Electric (GE), Westinghouse Electric Corporation, Westinghouse, AT&T Corporation and United Fruit Company. In 1932, RCA became an independent company after the partners were required to divest their ownership as part of the settlement of a government United States antitrust law, antitrust suit. An innovative and progressive company, RCA was the dominant electronics and communications firm in the United States for over five decades. In the early 1920s, RCA was at the forefront of the mushrooming radio industry as a major manufacturer of radio receivers, and the exclusive manufacturer of the first superheterodyne sets. The company also created the first nationwide American radio network, the National Broadcasting Company (NBC). RCA was also a pioneer in the introduction and development of television, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Television Technology
The technology of television has evolved since its early days using a mechanical system invented by Paul Gottlieb Nipkow in 1884. Every television system works on the scanning principle first implemented in the rotating disk scanner of Nipkow. This turns a two-dimensional image into a time series of signals that represent the brightness and color of each resolvable element of the picture. By repeating a two-dimensional image quickly enough, the impression of motion can be transmitted as well. For the receiving apparatus to reconstruct the image, synchronization information is included in the signal to allow proper placement of each line within the image and to identify when a complete image has been transmitted and a new image is to follow. While mechanically scanned systems were experimentally used, television as a mass medium was made practical by the development of electronic camera tubes and displays. By the turn of the 21st century, it was technically feasible to replace ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Display Technology
A display device is an output device for presentation of information in visual or tactile form (the latter used for example in tactile electronic displays for blind people). When the input information that is supplied has an electrical signal the display is called an '' electronic display''. Common applications for ''electronic visual displays'' are television sets or computer monitors. Types of electronic displays In use These are the technologies used to create the various displays in use today. * Liquid-crystal display (LCD) ** Light-emitting diode (LED) backlit LCD ** Thin-film transistor (TFT) LCD ** Quantum dot (QLED) display * Light-emitting diode (LED) display ** OLED display ** AMOLED display ** Super AMOLED display Segment displays Some displays can show only digits or alphanumeric characters. They are called segment displays, because they are composed of several segments that switch on and off to give appearance of desired glyph. The segments are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solid State (electronics)
Solid-state electronics are semiconductor electronics: electronic equipment that use semiconductor devices such as transistors, diodes and integrated circuits (ICs). The term is also used as an adjective for devices in which semiconductor electronics that have no moving parts replace devices with moving parts, such as the solid-state relay, in which transistor switches are used in place of a moving-arm electromechanical relay, or the solid-state drive (SSD), a type of semiconductor memory used in computers to replace hard disk drives, which store data on a rotating disk. History The term ''solid-state'' became popular at the beginning of the semiconductor era in the 1960s to distinguish this new technology. A semiconductor device works by controlling an electric current consisting of electrons or electron hole, holes moving within a solid crystalline piece of semiconductor, semiconducting material such as silicon, while the thermionic vacuum tubes it replaced worked by controll ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raytheon
Raytheon is a business unit of RTX Corporation and is a major U.S. defense contractor and industrial corporation with manufacturing concentrations in weapons and military and commercial electronics. Founded in 1922, it merged in 2020 with United Technologies Corporation to form Raytheon Technologies, which changed its name to RTX Corporation in July 2023. Raytheon was established in 1922, reincorporated in 1928, and adopted the Raytheon Company name in 1959. More than 90% of Raytheon's revenues were obtained from military contracts and, as of 2012, it was the fifth-largest military contractor in the world. , it was the third-largest defense contractor in the United States by defense revenue. It was the world's largest producer of guided missiles, and was involved in corporate and special-mission aircraft until early 2007. In 2018, the company had around 67,000 employees worldwide and annual revenues of about US$25.35 billion. Over the years, Raytheon shifted its headquarters ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Video Display Terminal
A computer terminal is an electronic or electromechanical hardware device that can be used for entering data into, and transcribing data from, a computer or a computing system. Most early computers only had a front panel to input or display bits and had to be connected to a terminal to print or input text through a keyboard. Teleprinters were used as early-day hard-copy terminals and predated the use of a computer screen by decades. The computer would typically transmit a line of data which would be printed on paper, and accept a line of data from a keyboard over a serial or other interface. Starting in the mid-1970s with microcomputers such as the Sphere 1, Sol-20, and Apple I, display circuitry and keyboards began to be integrated into personal and workstation computer systems, with the computer handling character generation and outputting to a CRT display such as a computer monitor or, sometimes, a consumer TV, but most larger computers continued to require terminals. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
