Témbongkeun sumber pikeun Cakram optik

{{redirect|Média optik|média transmisi keur cahaya|Médium (optika)}}
{{Optical disc authoring}}
[[Gambar:CD drive lens.jpg|thumb|200px|Lénsa optik nu maca [[compact disc]].]]

Dina [[komputasi]], [[réproduksi sora]], jeung [[vidéo]], hiji '''cakram optik''' nyaéta hiji cakram nu rata tur buleud (biasana [[polikarbonat]]) tempat nyimpen [[data]] dina  legok ''(pit)'' (atawa tonjolan ''(bump)'') dina beungeut ratana ''(flat surface)'' — nu ngaruntuy ''(sequential)'' ngawangun tapak ''(track)'' nu tuluy tinuluy ''(kontinyu)'' tur wangunna spiral nu ngagedéan ti tapak pangjerona ''(innermost track)'' tepi ka tapak pangluarna ''(outermost track)'', tepikeun ka nutupan sakabéh beungeut cakram. Data diaksés dina jero cakram nalika hiji bahan husus (seseringna mah [[aluminium]]) disorot ku [[dioda laser]]. Legok-legokna ngaganggu ampulna (refleksi) cahaya laser, nu ku sabab eta, lolobana cakram optik (kajaba cakram hideung dina [[konsol kaulinan vidéo]] ''(video game console)'' [[PlayStation]] asli), sacara husus boga panémbong ''(appearance)'' nu mangrupa-rupa kelir ''([[iridescent]])'' nu dijieun ku alur ''(groove)'' tina lapisan nu ngampulkeun ''(reflective layer)''.

== Sajarah ==
{{tarjamahkeun|Inggris}}
In 1961 and 1969, [[David Paul Gregg]] régistered a patent for the analog optical disc for vidéo recording, (US Patent 3,430,966). It is of special interest that US Patent 4,893,297, filed 1968, issued 1990, generated [[royalty income]] for Pioneer Corporation’s [[DVA]] until 2007 — encompassing the CD, DVD, and Blu-ray disc systems. In the éarly 1960s, the Music Corporation of America bought Gregg's patents and his company, [[Gauss Electrophysics]].

Likewise, in 1969 Holland, [[Philips]] Reséarch [[physicists]] began their first optical vidéodisc experiments at Eindhoven. In 1975, Philips and MCA join efforts, and in 1978, commercially much too late, they presented their long-awaited [[laserdisc]] in Atlanta, Géorgia, USA MCA delivered the discs, Philips the players; the presentation was a technical and commercial failure; the Philips/MCA cooperation ended.

In Japan and the U.S., [[Pioneer Corporation|Pioneer]] succeeded with the vidéodisc until the advent of the DVD. In 1979, Philips and [[Sony]], in consortium, successfully developed the [[compact disc]] in 1983. The [[Optical Storage Technology Association]] (OSTA) promote standardised optical storage méans. Although optical discs are more durable than éarlier audio-visual and data storage formats, they are susceptible to environmental and daily-use damage. Libraries and archives enact [[optical media preservation]] procedures to ensure continued usability in the computer's optical disc drive or corresponding disc player.

=== Generasi kahiji ===
Initially, optical discs were for storing music and computer software. The laser disc format stored analog vidéo signals, but, commercially, lost to the [[VHS]] vidéotape cassette, mainly its high cost and non-recordability; other first-generation disc formats are designed solely to store digital data.

Most first-generation disc devices had an infrared laser réading héad. The minimum size of the laser spot is proportional to its wavelength, thus wavelength is a limiting factor against gréat information density, too little data can be stored so. The infrared range is beyond the long-wavelength end of the visible light spectrum, so, supports less density than any visible light colour.  One example of high-density data storage capacity, achieved with an infrared laser, is  700MB of net user data for a 12&nbsp;cm compact disc.

'''NOTE:''' other factors affecting data storage density are, for example, a multi-layered infrared disc would hold more data than an identical single-layer disc; whether CAV, CLV, or zoned-CAV; how the data are encoded; how much cléar margin at the center and the edge

* [[Compact Disc]] (CD)
* [[Laser disc]]
* [[Magneto-optical disc]]
** [[mini disc]]

=== Generasi kadua ===
Second-generation optical discs were for storing gréat amounts of data, including broadcast-quality digital vidéo. Such discs usually are réad with a visible-light laser (usually red); the shorter wavelength and gréater [[numerical aperture]]<ref name="Crutchfield Advisor">[http://www.crutchfieldadvisor.com/S-UNO5yLxzuZf/learningcenter/home/hd_blu.html?page=2 Format War Update: Blu-ray Wins Over HD DVD<!-- Bot generated title -->]</ref> allow a narrower light béam, permitting smaller pits and lands in the disc. In the DVD format, this allows 4.7GB storage on a standard 12&nbsp;cm, single-sided, single-layer disc; alternately, smaller media, such as the [[MiniDisc]] and the [[DataPlay]] formats, can have capacity comparable to that of the larger, standard compact 12&nbsp;cm disc.

* [[Hi-MD]]
* [[DVD]] and derivatives
** [[DVD-Audio]]
** [[DualDisc]]
** [[DIVX|Digital Video Express]] (DIVX)
* [[Super Audio CD]]
* [[Enhanced Versatile Disc]]
* [[GD-ROM]]
* [[Digital Multilayer Disk]]
* [[DataPlay]]
* [[Fluorescent Multilayer Disc]]
* [[Phase-change Dual]]
* [[Universal Media Disc]]

=== Generasi katilu ===
Third-generation optical discs are in development, méant for distributing [[HDTV|high-definition video]] and support gréater data storage capacities, accomplished with short-wavelength visible-light lasers and gréater numerical apertures. The Blu-ray disc uses blue-violet lasers of gréater aperture, for use with discs with smaller pits and lands, thereby gréater data storage capacity per layer.<ref name="Crutchfield Advisor"/> In practice, the effective, multimedia presentation capacity is improved with enhanced vidéo [[data compression]] [[codec]]s such as [[H.264]], and [[VC-1]].

* Nu dikirimkeun kiwari:
** [[Blu-ray Disc]]
* Dina pengembangan:
** [[Forward Versatile Disc]]
** [[Versatile Multilayer Disc]]
** [[Ultra Density Optical]]
** [[LS-R]]

=== Generasi satuluyna ===
Format ieu aya sahareupeun cakram nu aya kiwari (generasi katilu), boga potensial leuwih ti sa-terabyte (1[[terabyte|TB]]) rohangan panyimpen data.

* [[Tapestry Media]]
* [[Holographic Versatile Disc]]
* [[Protein-coated disc]]

== Cakram optik nu bisa direkam jeung ditulisan ==
{{utama|Optical disc recording technologies}}

== Spésifikasi ==
{| class="wikitable" 
|+ Gancang dasar (1×) jeung maksimum (kiwari) dumasar generasi
!rowspan="2"| Generasi
! Dasar
!colspan="2"| Maks
|-
! (Mbit/det)
! (Mbit/det)
! ×
|-
| Ka- (CD)
| 1.17
| 65.62 || 56× <!-- speeds above 48x can result in [[CD shattering]], and so 48x and 52x are the most common maximum speeds for CD drives, though some drives have been sold at 56x [http://reviews.cnet.com/cd-drives/benq-656a-56x-cd/4505-3207_7-20383339.html] -->
|-
| Ka-2 (DVD)
| 10.55
| 210.94 || 20× <!-- industry maximum speed currently at 20x [http://benq.com/products/Storage/?product=979&page=specifications] -->
|-
| Ka-3 (BD)
| 36
| 432 || 12× <ref>{{cite news |url=http://www.cdrinfo.com/Sections/News/Details.aspx?NewsId=21958 |title=LG 6x Blu-ray Burner Available in Korea |publisher=CDRinfo.com}}</ref>
|-
|}

{| class="wikitable"
|+ Kapasitas jeung tata ngaran<ref>[http://www.mpeg.org/MPEG/DVD/Book_A/Specs.html MPEG: DVD, Book A – Physical parameters] {{Webarchive|url=https://web.archive.org/web/20120219232931/http://www.mpeg.org/MPEG/DVD/Book_A/Specs.html |date=2012-02-19 }}</ref><ref>[http://www.cinram.com/dvd/tech/dvdindetail.pdf DVD in Detail]</ref>
!colspan="2" rowspan="2"| Tanda
!rowspan="2"| Sisi !!rowspan="2"| Lapisan<br />(total) !! Gurat tengah !!colspan="2"| Kapasitas <!-- raw or user data? -->
|-
! (cm) !! ([[Gigabita|GB]]) !!align=right| ([[Gibibita|GiB]])
|-
| DVD-1  ||title="single-sided, single-layer"| SS SL 
|align=right| 1 ||align=right| 1 ||align=right|  8 ||align=right| 1.46 ||align=right| 1.36
|-
| DVD-2 || title="single-sided, double-layer"| SS DL
|align=right| 1 ||align=right| 2 ||align=right|  8 ||align=right| 2.66 ||align=right| 2.47
|-
| DVD-3 || title="double-sided, single-layer"| DS SL
|align=right| 2 ||align=right| 2 ||align=right|  8 ||align=right| 2.92 ||align=right| 2.72
<!--|-
| DVD-4? ||title="double-sided, double- and single-layer"| DS DL/SL
|align=right| 2 ||align=right| 3 ||align=right|  8 ||align=right| 4.12 ||align=right| 3.84--><!-- calculated, doubtful such discs ever existed -->
|-
| DVD-4 ||title="double-sided, double-layer"| DS DL
|align=right| 2 ||align=right| 4 ||align=right|  8 ||align=right| 5.32 ||align=right| 4.95
|-
| DVD-5  ||title="single-sided, single-layer"| SS SL 
|align=right| 1 ||align=right| 1 ||align=right| 12 ||align=right| 4.70  ||align=right| 4.37
|-
| DVD-9  ||title="single-sided, double-layer"| SS DL
|align=right| 1 ||align=right| 2 ||align=right| 12 ||align=right| 8.54 ||align=right| 7.95
|-
| DVD-10 ||title="double-sided, single-layer"| DS SL
|align=right| 2 ||align=right| 2 ||align=right| 12 ||align=right| 9.40  ||align=right| 8.74
|-
| DVD-14 ||title="double-sided, double- and single-layer"| DS DL/SL
|align=right| 2 ||align=right| 3 ||align=right| 12 ||align=right| 13.24 ||align=right| 12.32 <!--calculated from data above-->
|-
| DVD-18  ||title="double-sided, double-layer"| DS DL
|align=right| 2 ||align=right| 4 ||align=right| 12 ||align=right| 17.08 ||align=right| 15.90
|-
| DVD-R 1.0 ||title="single-sided, single-layer"| SS SL 
|align=right| 1 ||align=right| 1 ||align=right| 12 ||align=right| 3.95 ||align=right| 3.68
|-
| DVD-R 2.0 ||title="single-sided, single-layer"| SS SL 
|align=right| 1 ||align=right| 1 ||align=right| 12 ||align=right| 4.70 ||align=right| 4.37
|-
| DVD-R 2.0 ||title="double-sided, single-layer"| DS SL 
|align=right| 2 ||align=right| 2 ||align=right| 12 ||align=right| 9.40 ||align=right| 8.75
|-
| DVD-RW 2.0 ||title="single-sided, single-layer"| SS SL
|align=right| 1 ||align=right| 1 ||align=right| 12 ||align=right| 4.70 ||align=right| 4.37
|-
| DVD-RW 2.0 ||title="double-sided, single-layer"| DS SL
|align=right| 2 ||align=right| 2 ||align=right| 12 ||align=right| 9.40 ||align=right| 8.75
|-
| DVD+R 2.0 ||title="single-sided, single-layer"| SS SL 
|align=right| 1 ||align=right| 1 ||align=right| 12 ||align=right| 4.70 ||align=right| 4.37
|-
| DVD+R 2.0 ||title="double-sided, single-layer"| DS SL 
|align=right| 2 ||align=right| 2 ||align=right| 12 ||align=right| 9.40 ||align=right| 8.75
|-
| DVD+RW 2.0 ||title="single-sided, single-layer"| SS SL 
|align=right| 1 ||align=right| 1 ||align=right| 12 ||align=right| 4.70 ||align=right| 4.37
|-
| DVD+RW 2.0 ||title="double-sided, single-layer"| DS SL 
|align=right| 2 ||align=right| 2 ||align=right| 12 ||align=right| 9.40 ||align=right| 8.75
|-
| DVD-RAM 1.0 ||title="single-sided, single-layer"| SS SL 
|align=right| 1 ||align=right| 1 ||align=right| 12 ||align=right| 2.58 ||align=right| 2.40
|-
| DVD-RAM 1.0 ||title="double-sided, single-layer"| DS SL 
|align=right| 2 ||align=right| 2 ||align=right| 12 ||align=right| 5.16 ||align=right| 4.80
|-
| DVD-RAM 2.0 ||title="single-sided, single-layer"| SS SL 
|align=right| 1 ||align=right| 1 ||align=right| 12 ||align=right| 4.70 ||align=right| 4.37
|-
| DVD-RAM 2.0 ||title="double-sided, single-layer"| DS SL 
|align=right| 2 ||align=right| 2 ||align=right| 12 ||align=right| 9.40 ||align=right| 8.75<!--*-->
|-
| DVD-RAM 2.0 ||title="single-sided, single-layer"| SS SL 
|align=right| 1 ||align=right| 1 ||align=right|  8 ||align=right| 1.46 ||align=right| 1.36<!--*-->
|-
| DVD-RAM 2.0 ||title="double-sided, single-layer"| DS SL 
|align=right| 2 ||align=right| 2 ||align=right|  8 ||align=right| 2.65 ||align=right| 2.47<!--*-->
|-
| CD-ROM 74 min ||title="single-sided, single-layer"| SS SL 
|align=right| 1 ||align=right| 1 ||align=right| 12 ||align=right| 0.682 ||align=right| 0.635
|-
| CD-ROM 80 min ||title="single-sided, single-layer"| SS SL 
|align=right| 1 ||align=right| 1 ||align=right| 12 ||align=right| 0.737 ||align=right| 0.687
|-
| CD-ROM ||title="single-sided, single-layer"| SS SL 
|align=right| 1 ||align=right| 1 ||align=right|  8 ||align=right| 0.194 ||align=right| 0.180
|-
| DDCD-ROM ||title="single-sided, single-layer"| SS SL 
|align=right| 1 ||align=right| 1 ||align=right| 12 ||align=right| 1.364 ||align=right| 1.270
|-
| DDCD-ROM ||title="single-sided, single-layer"| SS SL 
|align=right| 1 ||align=right| 1 ||align=right|  8 ||align=right| 0.387 ||align=right| 0.360
|-
| HD DVD<!-- -ROM/-R/-RW --> || SS SL 
|align=right| 1 ||align=right| 1 ||align=right|  8 ||align=right| 4.70 || 
|-
| HD DVD || SS DL 
|align=right| 1 ||align=right| 2 ||align=right|  8 ||align=right| 9.40 || 
|-
| HD DVD || DS SL 
|align=right| 2 ||align=right| 2 ||align=right|  8 ||align=right| 9.40 ||
|-
| HD DVD || DS DL 
|align=right| 2 ||align=right| 4 ||align=right|  8 ||align=right| 18.80 || 
|-
| HD DVD || SS SL 
|align=right| 1 ||align=right| 1 ||align=right| 12 ||align=right| 15.00 || 
|-
| HD DVD || SS DL 
|align=right| 1 ||align=right| 2 ||align=right| 12 ||align=right| 30.00 || 
|-
| HD DVD || DS SL 
|align=right| 2 ||align=right| 2 ||align=right| 12 ||align=right| 30.00 || 
|-
| HD DVD || DS DL 
|align=right| 2 ||align=right| 4 ||align=right| 12 ||align=right| 60.00 || 
|-
| HD DVD-RAM || SS SL 
|align=right| 1 ||align=right| 1 ||align=right| 12 ||align=right| 20.00 || 
|}

== Rujukan ==
<references/>
* {{cite web |title=Inventor of the Week Archive: The Digital Compact Disc |publisher=Massachusetts Institute of Technology |date=December, 1999 |url=http://web.mit.edu/invent/iow/russell.html |accessdate=2007-07-13 }} {{Webarchive|url=https://web.archive.org/web/20030417162935/http://web.mit.edu/invent/iow/russell.html |date=2003-04-17 }}
* {{cite web |title=Scientist's invention was let go for a song |publisher=The Seattle Times |date=November 29, 2004 |url=http://seattletimes.nwsource.com/html/businesstechnology/2002103322_cdman29.html |accessdate=2007-07-13 |author=Brier Dudley }}
* {{cite web |title=David Gregg and the Optical Disk |publisher=About.com |url=http://inventors.about.com/library/inventors/blopticaldisk.htm |accessdate=2007-07-13 }} {{Webarchive|url=https://web.archive.org/web/20200819105952/https://www.thoughtco.com/david-gregg-and-the-optical-disk-1992209 |date=2020-08-19 }}

== Tumbu luar ==
* [http://www.osta.org Optical Storage Technology Association]
* [http://www.osta.org/technology/dvdqa/ Understanding Recordable & Rewritable DVD] by Hugh Bennett
* [http://www.osta.org/technology/cdqa.htm Understanding CD-R & CD-RW] by Hugh Bennett
* [http://www.memorex.com/downloads/whitepapers/Reference%20Guide%20for%20Optical%20Media%209-9.pdf Reference guide for optical media] {{Webarchive|url=https://web.archive.org/web/20090711175011/http://www.memorex.com/downloads/whitepapers/Reference%20Guide%20for%20Optical%20Media%209-9.pdf |date=2009-07-11 }} by Terence O'Kelly (Memorex Inc.)

{{Optical storage media}}

[[Kategori:Panyimpen komputer]]
[[Kategori:CD]]
[[Kategori:DVD]]
[[Kategori:Optical disc authoring]]
[[Kategori:Optoéléktronika]]

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