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Helical Scan
Helical scan is a method of recording high-frequency signals on magnetic tape, used in open-reel video tape recorders, video cassette recorders, digital audio tape recorders, and some computer tape drives. With this technique, magnetic tape heads (or head chips) are placed on a rotating head drum, which moves the chips at high speed by due to its high angular velocity. The speed of the head chips must be higher than the linear speed of the tape. The tape is wrapped tightly around the drum. The drum and/or the tape is tilted at an angle that allows the head chips to read the tape diagonally. The linear speed of the tape is slower than the speed of the head chips, allowing high frequency signals to be read or recorded, such as video. As the tape moves linearly or length-wise, the head chips move across the width of the tape in a diagonal path. Due to geometry, this allows for high head chip speeds, known as writing speeds, to be achieved in spite of the low linear speed of the tap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Tape
Magnetic tape is a medium for magnetic storage made of a thin, magnetizable coating on a long, narrow strip of plastic film. It was developed in Germany in 1928, based on the earlier magnetic wire recording from Denmark. Devices that use magnetic tape can with relative ease record and play back audio, visual, and binary computer data. Magnetic tape revolutionized sound recording and reproduction and broadcasting. It allowed radio, which had always been broadcast live, to be recorded for later or repeated airing. Since the early 1950s, magnetic tape has been used with computers to store large quantities of data and is still used for backup purposes. Magnetic tape begins to degrade after 10–20 years and therefore is not an ideal medium for long-term archival storage. The exception is data tape formats like Linear Tape-Open, LTO which are specifically designed for long-term archiving. Information in magnetic tapes is often recorded in tracks which are narrow and long areas of in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audiovisual Introductions In 1953
Audiovisual (AV) is electronic media possessing both a sound and a visual component, such as slide-tape presentations, films, television programs, corporate conferencing, church services, and live theater productions. Audiovisual service providers frequently offer web streaming, video conferencing, and live broadcast services. The professional audio visual industry has companies that provide hardware, software and services. These organizations are commonly referred to as ''systems integrators'' and perform both the installation and integration of different types of AV equipment from multiple manufacturers into spaces to create the AV experience for the user or audience. Computer-based audiovisual equipment is often used in education, with many schools and universities installing projection equipment and using interactive whiteboard technology. Components Aside from equipment installation, two significant elements of audiovisual are wiring and system control. If either of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Experimental Television Center
Experimental Television Center is a 501(c)(3) nonprofit electronic and media art center. History The Experimental Television Center (ETC) was founded in 1971 by Ralph Hocking. The center was the result of the expansion of a media access program that Ralph Hocking established as professor of video and computer art at Binghamton University in 1969. In July 1979, the center moved from Binghamton to Owego, New York. The ETC, directed by Ralph Hocking and Sherry Miller Hocking, is devoted to the exploration and development of potential uses of new technology in video and media art. Artists, organizations, and interested individuals were provided access to custom, innovative image processing tools. Complete use of the equipment and studio facilities was provided at no charge. The Center for more than 40 years offered a residency program, that emphasized the aesthetic experimentation of electronic and media art though new technologies. Artists and students from around the world wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symmetric Phase Recording
Symmetric Phase Recording is a tape recording ( computer storage media) technology developed by Quantum Corporation packs data across a tape's recording surface by writing adjacent tracks in a herringbone pattern: track 0 = \\\\\, track 1 = /////, track 2 = \\\\\, track 3 = /////, etc. This eliminates crosstrack interference and guard bands so that more tracks of data can be stored on a tape. See also * Azimuth recording, Slant Azimuth recording *Digital Equipment Corporation *Digital Linear Tape *Linear Tape-Open * Digital Tape Format *Helical scan *Magnetic tape *Magnetic tape data storage *Storage Technology Corporation Storage Technology Corporation (StorageTek or STK, earlier STC) was a data storage technology company headquartered in Louisville, Colorado. New products include data retention systems, which it calls "information lifecycle management" (ILM). It ... References Further reading * * Storage media {{Compu-hardware-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ampex 2 Inch Helical VTR
From 1963 to 1970, Ampex manufactured several models of VTR 2-inch helical VTRs, capable of recording and playing back analog black and white video. Recording employed non-segmented helical scanning, with one wrap of the tape around the video head drum being a little more than 180 degrees, using two video heads. One video drum rotation time was two fields of video. The units had two audio tracks recorded on the top edge of the tape, with a control track recorded on the tape's bottom edge. The 2-inch-wide video tape used was one mil (0.001 in or 0.0254 mm) thick. The VTRs were mostly used by industrial companies, educational institutions, and a few for in-flight entertainment. The capstan tape speed is 3.7 inches per second, which provided a long record time of up to five hours on large reels. The units were 100% solid state. The Ampex 2-inch helical VTRs were popular, as they were priced much less than the 2-inch quadruplex videotape recorders used in the broadcast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vision Electronic Recording Apparatus
Vision Electronic Recording Apparatus (VERA) was an early analog recording videotape format developed from 1952 by the BBC under project manager Dr Peter Axon. History In order to record high frequencies, a tape must move rapidly with respect to the recording or playback head. The frequencies used by video signals are so high that the tape/head speed is on the order of several meters per second (tens of feet per second), an order of magnitude faster than professional analog audio tape recording. The BBC solved the problem by using reels of magnetic tape that passed static heads at a speed of . VERA was capable of recording about 15 minutes (e.g. 4,572 meters) of 405-line black-and-white video per reel, and the picture tended to wobble because of some jitter (uneven speed) of the tape transport. Later video recorders used a time base corrector to remove this jitter and make synchronization with the studio house possible. In order to cope with 625-line PAL or SECAM colour t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Video Tape Recorder
A video tape recorder (VTR) is a tape recorder designed to record and playback video and audio signal, audio material from magnetic tape. The early VTRs were open-reel devices that record on individual reels of 2-inch-wide (5.08 cm) tape. They were used in television studios, serving as a replacement for motion picture film stock and making recording for television applications cheaper and quicker. Beginning in 1963, videotape machines made instant replay during televised sporting events possible. Improved formats, in which the tape was contained inside a videocassette, were introduced around 1969; the machines which play them are called videocassette recorders. An agreement by Japanese manufacturers on a common standard recording format, which allowed cassettes recorded on one manufacturer's machine to play on another's, made a consumer market possible; and the first consumer videocassette recorder, which used the U-matic format, was introduced by Sony in 1971. History ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IVC Videotape Format
IVC 2-inch Helical scan was a high-end, broadcast quality helical scan analog recording format developed by the International Video Corporation (IVC) and introduced in 1975. Prior to this, IVC had produced several helical scan video tape recorders (VTRs). Seeking to combine the image quality of the magnetic tape used with quadruplex videotape systems, with the advantages of helical scan technology, the company developed the ''IVC-9000'', a VTR for professional and broadcast applications. Versions *IVC made the Model 9000 in five versions ionlamb.us IVC VTR list**IVC 9000 (NTSC and PAL unit, could record for 2 hours on one 10.5 inch reel) **IVC 9000-4 (4 ips tape speed, Long Play, could record and play back 4 hours on one 10.5 inch reel **IVC 9000-W (8 MHz record and playback for super bandwidth) **IVC 9000-M (could record and playback video in the 655-line/ 48 field per second (24 frame/s) video standard) **IVC 9000-W-M (An IVC 9000-M with options from the 9000-W adde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1 Inch Type C Videotape
1-inch Type C Helical Scan or SMPTE C is a professional reel-to-reel analog recording helical scan videotape format co-developed by Ampex and Sony in 1976. The format uses tape and became the replacement in the professional video and broadcast television industries for the then-incumbent quadruplex videotape open-reel format. Additionally, it replaced the unsuccessful type A format, also developed by Ampex, and primarily in mainland Europe, it supplemented the type B format, developed by the Fernseh division of Bosch. Technical detail Compared to Quad, Type C had a smaller size, comparative ease of operation, and slightly higher video quality. 1-inch Type C is capable of "trick-play" functions such as still, shuttle, and variable-speed playback, including slow motion. 2-inch quadruplex videotape machines lacked these capabilities, due to the segmented manner in which it recorded video tracks onto the magnetic tape. 1-inch Type C VTRs required much less maintenance and used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1 Inch Type B Videotape
1-inch Type B Helical Scan or SMPTE B is a reel-to-reel analog recording video tape format developed by the Bosch Fernseh division of Bosch in Germany in 1976. The format uses magnetic tape and became the broadcasting standard in continental Europe, but adoption was limited in the United States and United Kingdom, where the Type C videotape format met with greater success. Details The tape speed allowed 96 minutes on a large reel (later 120 minutes), and used 2 record/playback (R/P) heads on the drum rotating at 9,000 RPM with a 190-degree wrap around a very small head drum, recording 52 video lines per head segment. A single video frame or field was recorded across 6 tracks in the tape. The format only allowed for play, rewind and fast forward. Video is recorded on an FM signal with a bandwidth of 5.5 MHz. Three longitudinal audio tracks are recorded on the tape as well: two audio and one Linear timecode (LTC) track. BCN 50 VTRs were used at the 1980 Summer Olympics in Mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type A Videotape
1-inch Type A Helical Scan or SMPTE A is a reel-to-reel helical scan analog recording videotape format developed by Ampex in 1965, that was one of the first standardized reel-to-reel magnetic tape formats in the width; most others of that size at that time were proprietary. It was capable of 350 lines. Usage Type A was developed as mainly an industrial and institutional format, where it saw the most success. It was not widely used for broadcast television, since it did not meet Federal Communications Commission (FCC) specifications for broadcast videotape formats; the only format passing the FCC's muster at the time was the then-industry-standard 2-inch quadruplex. The Type A format received broad use by the White House Communications Agency from 1966 to 1969. The WHCA, under U.S. President Lyndon B. Johnson, used the format to videotape television broadcasts off the air or from direct White House feeds. The WHCA recorded programs and events including television a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
