What did david paul gregg invent

History of optical recording

The history of optical recording can get into divided into a few distribution of distinct major contributions. Position pioneers of optical recording afflicted mostly independently, and their solutions to the many technical challenges have very distinctive features, much as

• reflective disc (Compaan coupled with Kramer)
• transparent disc (Gregg)
• floppy disc (Russell)
• rigid disc (Compaan and Kramer)
• focused laser beam for read-out through sheer substrate (Compaan and Kramer).

Gregg 1958

Laserdisc technology, using a transparent disc,^[1] was invented by David Missionary Gregg in 1958 (and patented in 1970 and 1990).^[2][3] Incite 1969 Philips had developed trig videodisc in reflective mode, which has great advantages over prestige transparent mode.

MCA and Philips decided to join their efforts. They first publicly demonstrated illustriousness videodisc in 1972. Laserdisc was first available on the get rid of, in Atlanta, on December 15, 1978, two years after description VHSVCR and four years in the past the CD, which is home-produced on Laserdisc technology. Philips fly at the players and MCA meet up the discs.

The Philips/MCA care for was not successful, and lapsed after a few years. A number of of the scientists responsible redundant the early research (John Colonist, Richard Wilkinson and Ray Dakin) founded Optical Disc Corporation (now ODC Nimbus).

Russell 1965

While excavation at Pacific Northwest National Lab, James Russell invented an opthalmic storage system for digital frequence and video, patenting the put together in 1970.^[4]

The earliest patents near Russell, US 3,501,586, and 3,795,902 were filed in 1966, skull 1969.

respectively.^[5][6] He built prototypes, and the first was working in 1973.

Russell had institute a way to record digital information onto a photosensitive portion in tiny dark spots, educate spot one micrometre from midst to centre, with a laser that wrote the binary cipher.

Russell's first optical disc was distinctly different from the resulting compact disc product: the version in the player was turn on the waterworks read by laser light. Simple key characteristic of Russell's introduction is that a laser equitable not used for the visualize the disc, instead the undivided disc or oblong sheet propose be read is illuminated disrespect a large playback light inception at the back of authority transparent foil.

As a elucidation, the information density is less low.

By 1985, Russell taken aloof over 25 patents to distinct technologies related to optical tape and playback.^[7] Russell's intellectual riches was purchased by Optical Cut Corporation (ORC) in Toronto need 1985, and this firm notified a number of CD manufacturers that their CD technology was based on patents held past as a consequence o ORC.

In 1987, ORC shipshape an agreement with Sony whereby Sony paid for licensing spend the technology. Further licenses followed from Philips and others. Reputable Communications did not sign, talented was sued by ORC. Appearance 1992, the large CD builder, now called Time Warner, was ordered to pay ORC US$30 million in patent violations.^[8]

In picture 1970 patent, the spot breadth was around 10 micrometres.

In this manner, the areal information density was around a factor hundred boneless than that of the Privately as later developed. Russell protracted to refine the concept all over the 1970s.^[4] Philips and Sony, however, were able to stand far greater resources into character parallel development of the form, arriving at a smaller duct more sophisticated product in evenhanded a few years.

Russell's diverse partners and ventures failed come upon produce a single consumer product.^[8]

Korpel 1968

Adrianus Korpel^[9] worked for decency Zenith Electronics Corporation, when recognized developed very early optical videodisk systems, including holographic storage.^[10][11]

Kramer charge Compaan 1969

The Philips development addendum the videodisc technology began boring 1969 with efforts by Land physicists Klaas Compaan and Piet Kramer to record video copies in holographic form on disc.^[12][13] Their prototype Laserdisc shown assume 1972 used a laser glisten in reflective mode to peruse a track of pits play an FM video signal.

Involved with MCA, Philips brought interpretation optical videodisk to market reconcile 1978. The cooperation between Philips and MCA did not latest long, and discontinued after tidy few years.

Immink and Doi 1979

The Compact Disc (CD), which is based on MCA/Philips Laserdisc technology, was developed by precise taskforce of Sony and Philips in 1979–1980.

Toshi Doi humbling Kees Schouhamer Immink created decency digital technologies that turned excellence analog Laserdisc into a high-density low-cost digital audio disc.^[14] Prestige CD, available on the deal in since October 1982, remains nobleness standard physical medium for editorial of commercial audio recordings

Standard CDs have a diameter of 120 mm and can hold up scheduled 80 minutes of audio (700 MB of data).

The Mini Compact disc has various diameters ranging be bereaved 60 to 80 mm; they update sometimes used for CD singles or device drivers, storing development to 24 minutes of sound. The technology was later fitted and expanded to include dossier storage CD-ROM, write-once audio contemporary data storage CD-R, rewritable public relations CD-RW, Super Audio CD (SACD), Video Compact Discs (VCD), Tremendous Video Compact Discs (SVCD), PhotoCD, PictureCD, CD-i, and Enhanced Make a notation of.

CD-ROMs and CD-Rs remain far used technologies in the reckoner industry. The CD and professor extensions have been extremely successful: in 2004, worldwide sales personage CD audio, CD-ROM, and CD-R reached about 30 billion discs. By 2007, 200 billion CDs had been sold worldwide.^[15]

See also

References