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96-516: BD-J allows for more sophisticated bonus content on Blu-ray Disc titles than standard DVD , including network access, picture-in-picture, and access to expanded local storage . Collectively, these features (other than internet access) are referred to as " Bonus View ", and the addition of internet access is called " BD Live ". BD-J was developed by the Blu-ray Disc Association . All Blu-ray Disc players supporting video content are required by

192-640: A (shallow) groove, a first data layer, a semi-reflective layer, a second (spacer) polycarbonate layer with another (deep) groove, and a second data layer. The first groove spiral usually starts on the inner edge and extends outwards, while the second groove start on the outer edge and extends inwards. Some drives support Hewlett-Packard 's LightScribe , or the alternative LabelFlash photothermal printing technology for labeling specially coated discs. Zen Technology and Sony have developed drives that use several laser beams simultaneously to read discs and write to them at higher speeds than what would be possible with

288-480: A DVD player, a figure that had surpassed VCRs; it was also higher than personal computers or cable television. The DVD specifications created and updated by the DVD Forum are published as so-called DVD Books (e.g. DVD-ROM Book, DVD-Audio Book, DVD-Video Book, DVD-R Book, DVD-RW Book, DVD-RAM Book, DVD-AR (Audio Recording) Book, DVD-VR (Video Recording) Book, etc.). DVD discs are made up of two discs; normally one

384-809: A NIST/ LoC research project conducted in 2005–2007 using accelerated life testing , "There were fifteen DVD products tested, including five DVD-R, five DVD+R, two DVD-RW and three DVD+RW types. There were ninety samples tested for each product. ... Overall, seven of the products tested had estimated life expectancies in ambient conditions of more than 45 years. Four products had estimated life expectancies of 30–45 years in ambient storage conditions. Two products had an estimated life expectancy of 15–30 years and two products had estimated life expectancies of less than 15 years when stored in ambient conditions." The life expectancies for 95% survival estimated in this project by type of product are tabulated below: Optical disc drive In computing , an optical disc drive (ODD)

480-446: A November 1997 online interview, and clarified it would release discs in early 1998. However, this date would be pushed back several times before finally releasing their first titles at the 1999 Consumer Electronics Show . In 2001, blank DVD recordable discs cost the equivalent of $ 27.34 US dollars in 2022. Movie and home entertainment distributors adopted the DVD format to replace

576-415: A computer's USB port . (In some slim drives, two USB connectors are required, each supplying power, but only one the data.) Half height drives are also faster than Slim drives due to this, since more power is required to spin the disc at higher speeds. Half-height optical drives hold discs in place from both sides while slim type optical drives fasten the disc from the bottom. Half height drives fasten

672-634: A computer. DVD players are a particular type of devices that do not require a computer to work, and can read DVD-Video and DVD-Audio discs. Read and write speeds for the first DVD drives and players were 1,385  kB /s (1,353  KiB /s); this speed is usually called "1×". More recent models, at 18× or 20×, have 18 or 20 times that speed. For CD drives, 1× means 153.6 kB/s (150 KiB/s), about one-ninth as swift. DVDs can spin at much higher speeds than CDs – DVDs can spin at up to 32000 RPM vs 23000 for CDs. In practice, they are not spun by optical drives anywhere close to these speeds to provide

768-479: A constant number of revolutions per minute (RPM). With CAV, a higher throughput is generally achievable at the outer disc compared to the inner. On the other hand, optical drives were developed with an assumption of achieving a constant throughput, in CD drives initially equal to 150 KiB /s. It was a feature important for streaming audio data that always tend to require a constant bit rate . But to ensure no disc capacity

864-420: A constraint on the maximum safe speeds (56× CAV for CDs or around 18×CAV in the case of DVDs) at which drives can operate. The reading speeds of most half-height optical disc drives released since c.  2007 are limited to ×48 for CDs, ×16 for DVDs and ×12 ( angular velocities ) for Blu-ray Discs. Writing speeds on selected write-once media are higher. Some optical drives additionally throttle

960-484: A cost: DVD±DLs have slower write speeds as compared to DVD±R. DVD-R DL was developed for the DVD Forum by Pioneer Corporation ; DVD+R DL was developed for the DVD+RW Alliance by Mitsubishi Kagaku Media (MKM) and Philips . Recordable DVD discs supporting dual-layer technology are backward-compatible with some hardware developed before the recordable medium. DVD drives are devices that can read DVD discs on

1056-439: A diffraction grating is used to split a laser beam into 7 beams, which are then focused into the disc; a central beam is used for focusing and tracking the groove of the disc leaving 6 remaining beams (3 on either side) that are spaced evenly to read 6 separate portions of the groove of the disc in parallel, effectively increasing read speeds at lower RPMs, reducing drive noise and stress on the disc. The beams then reflect back from

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1152-487: A double-sided disc. Philips and Sony decided that it was in their best interests to end the format war, and on September 15, 1995 agreed to unify with companies backing the Super Density Disc to release a single format, with technologies from both. After other compromises between MMCD and SD, the group of computer companies won the day, and a single format was agreed upon. The computer companies also collaborated with

1248-763: A dual-layer DVD up to 8.5 GB. Variants can store up to a maximum of 17.08 GB. Prerecorded DVDs are mass-produced using molding machines that physically stamp data onto the DVD. Such discs are a form of DVD-ROM because data can only be read and not written or erased. Blank recordable DVD discs ( DVD-R and DVD+R ) can be recorded once using a DVD recorder and then function as a DVD-ROM. Rewritable DVDs ( DVD-RW , DVD+RW , and DVD-RAM ) can be recorded and erased many times. DVDs are used in DVD-Video consumer digital video format and less commonly in DVD-Audio consumer digital audio format, as well as for authoring DVD discs written in

1344-401: A firmware upgrade used to showcase BD-Live at CES 2008. Content authors have a variety of development strategies available, including the use of traditional Integrated Development Environments (IDEs) like NetBeans or Eclipse , non-programming graphical environments similar to Macromedia Director, or via rendering engines which consume standard data formats such as HTML, XML, or SVG. Having

1440-603: A full programming environment available on every Blu-ray Disc player provides developers with a platform for creating content types not bound by the restrictions of standard DVD. In addition to the standard BD-J APIs, developers may make use of existing Java libraries and application frameworks, assuming they do not use features outside the constraints of the BD-J platform, include that Java ME only supports Java version 1.3 class files. A set of freely available tools that allow Java developers to produce complete disc images incorporating BD-J

1536-447: A lower reading speed improves readability of damaged media. With an option in the optical disc authoring software, optical disc writers are able to simulate the writing process on CD-R , CD-RW , DVD-R and DVD-RW , which allows for testing such as observing the writing speeds and patterns (e.g. constant angular velocity , constant linear velocity and P-CAV and Z-CLV variants) with different writing speed settings and testing

1632-477: A motorized mechanism that can be pushed to close, controlled by the computer, or controlled using a button on the drive. Trays on half height and slim drives can also be locked by whatever program is using it, however it can still be ejected by inserting the end of a paper clip into an emergency eject hole on the front of the drive. Early CD players such as the Sony CDP-101 used a separate motorized mechanism to clamp

1728-406: A motorized tray (as utilized by half-height , "desktop" drives), a manually operated tray (as utilized in laptop computers, also called slim type ), or a slot-loading mechanism, where the disc is slid into a slot and drawn in by motorized rollers. Slot-loading optical drives exist in both half-height (desktop) and slim type (laptop) form factors. With both types of mechanisms, if a CD or DVD

1824-482: A noticeable pause in A/V playback on earlier DVD players , the length of which varies between hardware. A printed message explaining that the layer-transition pause was not a malfunction became standard on DVD keep cases . During mastering, a studio could make the transition less obvious by timing it to occur just before a camera angle change or other abrupt shift, an early example being the DVD release of Toy Story . Later in

1920-405: A partial CLV (PCLV) scheme, by switching from CLV to CAV only when a rotational limit is reached. But switching to CAV requires considerable changes in hardware design, so instead most drives use the zoned constant linear velocity (Z-CLV) scheme. This divides the disc into several zones, each having its own constant linear velocity. A Z-CLV recorder rated at "52×", for example, would write at 20× on

2016-412: A point on the media, thus its power has to increase proportionally. DVD burners' lasers often peak at about 200 mW, either in continuous wave and pulses, although some have been driven up to 400 mW before the diode fails. For rewritable CD-RW , DVD-RW , DVD+RW , DVD-RAM , or BD-RE media, the laser is used to melt a crystalline metal alloy in the recording layer of the disc. Depending on

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2112-475: A press release stating that they would only accept a single format. The group voted to boycott both formats unless the two camps agreed on a single, converged standard. They recruited Lou Gerstner , president of IBM, to pressure the executives of the warring factions. In one significant compromise, the MMCD and SD groups agreed to adopt proposal SD 9, which specified that both layers of the dual-layered disc be read from

2208-536: A rabbit as the shooter and turtles as the targets) provided as an example in the Java ME 3.0 SDK . And the same for the other non- javax . * packages. Likewise, when trying to play a video, one might call the Blu-ray and DAVIC utility rather than using generic JMF: DVD The DVD (common abbreviation for digital video disc or digital versatile disc ) is a digital optical disc data storage format. It

2304-449: A safety margin. DVD drives limit reading speed to 16× (constant angular velocity), which means 9280 rotations per minute. Early-generation drives released before the mid-2000s have lower limits. DVD recordable and rewritable discs can be read and written using either constant angular velocity (CAV), constant linear velocity (CLV), Partial constant angular velocity (P-CAV) or Zoned Constant Linear Velocity (Z-CLV or ZCLV). Due to

2400-408: A semi-reflective layer. Both layers are accessible from the same side, but require the optics to change the laser's focus. Traditional single layer (SL) writable media are produced with a spiral groove molded in the protective polycarbonate layer (not in the data recording layer), to lead and synchronize the speed of recording head. Double-layered writable media have: a first polycarbonate layer with

2496-458: A single laser beam. The limitation with a single laser beam comes from wobbling of the disc that may occur at high rotational speeds; at 25,000 RPMs CDs become unreadable while Blu-rays cannot be written to beyond 5,000 RPMs. With a single laser beam, the only way to increase read and write speeds without reducing the pit length of the disc (which would allow for more pits and thus bits of data per revolution, but may require smaller wavelength light)

2592-420: A special AVCHD format to hold high definition material (often in conjunction with AVCHD format camcorders ). DVDs containing other types of information may be referred to as DVD data discs. The Oxford English Dictionary comments that, "In 1995, rival manufacturers of the product initially named digital video disc agreed that, in order to emphasize the flexibility of the format for multimedia applications,

2688-453: A standard DVD holds 4.7  gigabytes , however, higher-capacity formats such as multi-layer Blu-ray Discs exist) for local use, and data for distribution, but only on a small scale; mass-producing large numbers of identical discs by pressing (replication) is cheaper and faster than individual recording (duplication). To support 8 centimetre diameter discs, drives with mechanical tray loading (desktop computer drives) have an indentation in

2784-545: A standard definition CRT TV or an HD flat panel TV with a DVD mechanism under the CRT or on the back of the flat panel, and VCR/DVD combos were also available for purchase. For consumers, DVD soon replaced VHS as the favored choice for home movie releases. In 2001, DVD players outsold VCRs for the first time in the United States. At that time, one in four American households owned a DVD player. By 2007, about 80% of Americans owned

2880-415: A stop. The most important part of an optical disc drive is an optical path , which is inside a pickup head ( PUH ). The PUH is also known as a laser pickup, optical pickup, pickup, pickup assembly, laser assembly, laser optical assembly, optical pickup head/unit or optical assembly. It usually consists of a semiconductor laser diode , a lens for focusing the laser beam, and photodiodes for detecting

2976-432: A storage capacity of 4.7 GB (4.38 GiB ) for a single-layered, single-sided disc and 8.5 GB (7.92 GiB) for a dual-layered, single-sided disc. The DVD specification ended up similar to Toshiba and Matsushita's Super Density Disc, except for the dual-layer option. MMCD was single-sided and optionally dual-layer, whereas SD was two half-thickness, single-layer discs which were pressed separately and then glued together to form

BD-J - Misplaced Pages Continue

3072-654: A third one for Blu-ray Discs if supported by the drive ) that can be turned using a fine screwdriver. The potentiometer is in a series circuit with the laser lens. The laser diode used in DVD writers can have powers of up to 100 milliwatts , such high powers are used during writing. Some CD players have automatic gain control (AGC) to vary the power of the laser to ensure reliable playback of CD-RW discs. Readability (the ability to read physically damaged or soiled discs) may vary among optical drives due to differences in optical pickup systems, firmwares, and damage patterns. On factory-pressed read only media (ROM), during

3168-429: Is 1.385 MB/s, equal to 1.32 MiB/s, approximately nine times faster than the CD base speed. For Blu-ray drives, base speed is 6.74 MB/s, equal to 6.43 MiB/s. Because keeping a constant transfer rate for the whole disc is not so important in most contemporary CD uses, a pure CLV approach had to be abandoned to keep the rotational speed of the disc safely low while maximizing data rate. Some drives work in

3264-969: Is a disc drive that uses laser light or electromagnetic waves within or near the visible light spectrum as part of the process of reading or writing data to or from optical discs . Some drives can only read from certain discs, while other drives can both read and record. Those drives are called burners or writers since they physically burn the data onto on the discs. Compact discs , DVDs , and Blu-ray discs are common types of optical media which can be read and recorded by such drives. Although most laptop manufacturers no longer have optical drives bundled with their products, external drives are still available for purchase separately. Some drives can only read data where as others can both read data and write data to writable discs. Drives which can read but not write data are "-ROM" (read-only memory) drives, even if they can read from writable formats such as "-R" and "-RW". Some drives have mixed read and write capabilities, such as

3360-495: Is available from the HD Cookbook Project. In order to test content in a typical development environment (MS Windows), one needs either a PlayStation 3 or a third-party software player for Windows, paying attention to player versions to ensure that the player supports BD-J. Because of the many different standards and components involved, creating unified documentation on BD-J has proven to be a challenge. The BD-J environment

3456-419: Is available in two formats, General (650 nm) and Authoring (635 nm), where Authoring discs may be recorded with CSS encrypted video content but General discs may not. Dual-layer recording (occasionally called double-layer recording) allows DVD-R and DVD+R discs to store nearly double the data of a single-layer disc—8.5 and 4.7 gigabyte capacities, respectively. The additional capacity comes at

3552-462: Is blank, and the other contains data. Each disc is 0.6 mm thick, and are glued together to form a DVD disc. The gluing process must be done carefully to make the disc as flat as possible to avoid both birefringence and "disc tilt", which is when the disc is not perfectly flat, preventing it from being read. Some specifications for mechanical, physical and optical characteristics of DVD optical discs can be downloaded as freely available standards from

3648-450: Is by increasing the rotational speed of the disc which reads more pits in less time, increasing data rate; hence why faster drives spin the disc at higher speeds. In addition, CDs at 27,500 RPMs (such as to read the inside of a CD at 52x) may explode causing extensive damage to the disc's surroundings, and poor quality or damaged discs may explode at lower speeds. In Zen's system (developed in conjunction with Sanyo and licensed by Kenwood),

3744-525: Is designed to run Xlets with non- javax . * packages available to take advantage of the features particular to this platform beyond that defined by Java TV . Even a simple example such as FirstBDJApp. A developer might choose to use not javax . * packages and instead use: A working example of a program using some features from each of the class trees would be the BdjGunBunny Xlet (a very simple version of Space Invaders using an image of

3840-456: Is left in the drive after the computer is turned off, the disc cannot be ejected using the normal eject mechanism of the drive. However, tray-loading drives account for this situation by providing a small hole where one can insert a paperclip to manually open the drive tray to retrieve the disc. Slot-loading optical disc drives are prominently used in game consoles and vehicle audio units. Although allowing more convenient insertion, those have

3936-414: Is less practical. Large backups are often instead made on external hard drives, as their price has dropped to a level making this viable; in professional environments magnetic tape drives are also used. Some optical drives also allow predictively scanning the surface of discs for errors and detecting poor recording quality. The drive reduces the rotation speed of discs when encountering damage, since

BD-J - Misplaced Pages Continue

4032-450: Is lost. Numerous factors affect longevity: composition and quality of the media (recording and substrate layers), humidity and light storage conditions, the quality of the initial recording (which is sometimes a matter of mutual compatibility of media and recorder), etc. According to NIST , "[a] temperature of 64.4 °F (18 °C) and 40% RH [Relative Humidity] would be considered suitable for long-term storage. A lower temperature and RH

4128-492: Is measureable, which means that future data losses caused by deteriorating media can be predicted well in advance by measuring the rate of correctable data errors. Support of measuring the disc quality varies among optical drive vendors and models. DVD-Video is a standard for distributing video/audio content on DVD media. The format went on sale in Japan on November 1, 1996, in the United States on March 24, 1997, to line up with

4224-568: Is recommended for extended-term storage." As with CDs, the information and data storage will begin to degrade over time with most standard DVDs lasting up to 30 years depending on the type of environment they are stored and whether they are full with data. According to the Optical Storage Technology Association (OSTA), "Manufacturers claim lifespans ranging from 30 to 100 years for DVD, DVD-R and DVD+R discs and up to 30 years for DVD-RW, DVD+RW and DVD-RAM." According to

4320-478: Is the explanation provided in a DVD Forum Primer from 2000 and in the DVD Forum 's mission statement, which the purpose is to promote broad acceptance of DVD products on technology, across entertainment, and other industries. Because DVDs became highly popular for the distribution of movies in the 2000s, the term DVD became popularly used in English as a noun to describe specifically a full-length movie released on

4416-497: The 69th Academy Awards that day; in Canada, Central America, and Indonesia later in 1997; and in Europe, Australia, and Africa in 1998. DVD-Video became the dominant form of home video distribution in Japan when it first went on sale on November 1, 1996, but it shared the market for home video distribution in the United States for several years; it was June 15, 2003, when weekly DVD-Video in

4512-552: The ISO website. There are also equivalent European Computer Manufacturers Association (Ecma) standards for some of these specifications, such as Ecma-267 for DVD-ROMs. Also, the DVD+RW Alliance publishes competing recordable DVD specifications such as DVD+R, DVD+R DL, DVD+RW or DVD+RW DL . These DVD formats are also ISO standards. Some DVD specifications (e.g. for DVD-Video) are not publicly available and can be obtained only from

4608-607: The Optical Storage Technology Association (OSTA) on the use of their implementation of the ISO-13346 file system (known as Universal Disk Format ) for use on the new DVDs. The format's details were finalized on December 8, 1995. In November 1995, Samsung announced it would start mass-producing DVDs by September 1996. The format launched on November 1, 1996, in Japan, mostly with music video releases. The first major releases from Warner Home Video arrived on December 20, 1996, with four titles being available. The format's release in

4704-866: The PlayStation and Xbox consoles are the only home video game consoles that are currently using optical discs as its primary storage format, as the Wii U 's successor, the Nintendo Switch , began using game cartridges , while the PlayStation Portable is the only handheld console to use optical discs, using Sony's proprietary UMD format. They are also very commonly used in computers to read software and media distributed on disc and to record discs for archival and data exchange purposes. Floppy disk drives , with capacity of 1.44 MB, have been made obsolete: optical media are cheap and have vastly higher capacity to handle

4800-529: The TSST TS-LB23, which can only read Blu-ray discs but read and write CDs and DVDs. As of 2021 , most of the optical disc drives on the market are DVD and Blu-ray drives which read from and record to those formats, along with having backward compatibility with audio CD , CD-R / -RW , and CD-ROM discs. Compact disc drives are no longer manufactured outside of audio devices. Read-only DVD and Blu-ray drives are also manufactured, but are less commonly found in

4896-521: The format war of 2006–2008 . A dual layer HD DVD can store up to 30 GB and a dual layer Blu-ray disc can hold up to 50 GB. However, unlike previous format changes, e.g., vinyl to Compact Disc or VHS videotape to DVD, initially there was no immediate indication that production of the standard DVD will gradually wind down, as at the beginning of the 2010s they still dominated, with around 75% of video sales and approximately one billion DVD player sales worldwide as of April 2011. In fact, experts claimed that

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4992-460: The DVD Book assigns them distinct disc types. DVD-14 has no analogous 8 cm type. The comparative data for 8 cm discs is provided further down. HP initially developed recordable DVD media from the need to store data for backup and transport. DVD recordables are now also used for consumer audio and video recording. Three formats were developed: DVD-R / RW , DVD+R / RW (plus), and DVD-RAM . DVD-R

5088-643: The DVD Format/Logo Licensing Corporation (DVD FLLC) for a fee of US$ 5000. Every subscriber must sign a non-disclosure agreement as certain information on the DVD Books is proprietary and confidential. Borrowing from the LaserDisc format, the DVD standard includes DVD-10 discs (Type B in ISO) with two recorded data layers such that only one layer is accessible from either side of the disc. This doubles

5184-500: The DVD would remain the dominant medium for at least another five years as Blu-ray technology was still in its introductory phase, write and read speeds being poor and necessary hardware being expensive and not readily available. Consumers initially were also slow to adopt Blu-ray due to the cost. By 2009, 85% of stores were selling Blu-ray Discs. A high-definition television and appropriate connection cables are also required to take advantage of Blu-ray disc. Some analysts suggested that

5280-456: The U.S. was delayed multiple times, from August 1996, to October 1996, November 1996, before finally settling on early 1997. Players began to be produced domestically that winter, with March 24, 1997, as the U.S. launch date of the format proper in seven test markets. Approximately 32 titles were available on launch day, mainly from the Warner Bros. , MGM , and New Line libraries, with

5376-456: The United States rentals began outnumbering weekly VHS cassette rentals. DVD-Video is still the dominant form of home video distribution worldwide except for in Japan where it was surpassed by Blu-ray Disc when Blu-ray first went on sale in Japan on March 31, 2006. The purpose of CSS is twofold: In 2006, two new formats called HD DVD and Blu-ray Disc were released as the successor to DVD. HD DVD competed unsuccessfully with Blu-ray Disc in

5472-461: The amount of power applied, the substance may be allowed to melt back (change the phase back) into crystalline form or left in an amorphous form, enabling marks of varying reflectivity to be created. Double-sided media may be used, but they are not easily accessed with a standard drive, as they must be physically turned over to access the data on the other side. Double layer or dual layer (DL) media have two independent data layers separated by

5568-559: The biggest obstacle to replacing DVD was due to its installed base; a large majority of consumers were satisfied with DVDs. DVDs started to face competition from video on demand services around 2015. With increasing numbers of homes having high speed Internet connections, many people had the option to either rent or buy video from an online service, and view it by streaming it directly from that service's servers, meaning they no longer need any form of permanent storage media for video at all. By 2017, digital streaming services had overtaken

5664-596: The consumer market and mainly limited to media devices such as game consoles and disc media players. Laptop computers used to come with built-in optical drives. Some laptop computers used modular systems (see Lenovo UltraBay). Throughout the 2010s, they ceased to come with built-in optical disc drives in order to reduce costs and make them lighter, requiring consumers to purchase external optical drives. Optical disc drives are an integral part of standalone appliances such as CD players , DVD players , Blu-ray Disc players, DVD recorders , and video game consoles. As of 2017,

5760-422: The developers of the DVD format and eventually the first company to actually release a DVD-based console. Game consoles such as the PlayStation 2 , Xbox , and Xbox 360 use DVDs as their source medium for games and other software. Contemporary games for Windows were also distributed on DVD. Early DVDs were mastered using DLT tape, but using DVD-R DL or +R DL eventually became common. TV DVD combos , combining

5856-578: The disadvantages that they cannot usually accept the smaller 80 mm diameter discs (unless 80 mm optical disc adapter is used) or any non-standard sizes, usually have no emergency eject hole or eject button, and therefore have to be disassembled if the optical disc cannot be ejected normally. However, some slot-loading optical drives have been engineered to support miniature discs. The Nintendo Wii , because of backward compatibility with GameCube games, and PlayStation 3 video game consoles are able to load both standard size DVDs and 80 mm discs in

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5952-405: The disc to the motorized spindle. Slim drives use a special spindle with spring loaded specially shaped studs that radiate outwards, pressing against the inner edge of the disc. The user has to put uniform pressure onto the inner circumference of the disc to clamp it to the spindle and pull from the outer circumference while placing the thumb on the spindle to remove the disc, flexing it slightly in

6048-412: The disc using 2 spindles containing a magnet each, one under and one above the disc tray. The spindles may be lined with flocking or a texturized silicone material to exert friction on the disc, to keep it from slipping. The upper spindle is left slightly loose and is attracted to the lower spindle because of the magnets they have. When the tray is opened, a mechanism driven by the movement of the tray pulls

6144-410: The disc, and are collimated and projected into a special photodiode array to be read. The first drives using the technology could read at 40x, later increasing to 52x and finally 72x. It uses a single optical pickup. In Sony's system (used on their proprietary Optical Disc Archive system which is based on Archival Disc , itself based on Blu-ray) the drive has 4 optical pickups, two on each side of

6240-412: The disc, with each pickup having two lenses for a total of 8 lenses and laser beams. This allows for both sides of the disc to be read and written to at the same time, and for the contents of the disc to be verified during writing. The rotational mechanism in an optical drive differs considerably from that of a hard disk drive's, in that the latter keeps a constant angular velocity (CAV), in other words

6336-410: The dye, thereby creating marks that can be read like the pits and lands on pressed discs. For recordable discs, the process is permanent and the media can be written to only once. While the reading laser is usually not stronger than 5 mW , the writing laser is considerably more powerful. DVD lasers operate at voltages of around 2.5 volts. The higher the writing speed, the less time a laser has to heat

6432-889: The format's life, larger data buffers and faster optical pickups in DVD players made layer transitions effectively invisible regardless of mastering. Dual-layer DVDs are recorded using Opposite Track Path (OTP). The DVD Book also permits an additional disc type called DVD-14: a hybrid double-sided disc with one dual-layer side, one single-layer side, and a total nominal capacity of 12.3 GB. DVD-14 has no counterpart in ISO. Both of these additional disc types are extremely rare due to their complicated and expensive manufacturing. For this reason, some DVDs that were initially issued as double-sided discs were later pressed as two-disc sets. Note : The above sections regarding disc types pertain to 12 cm discs. The same disc types exist for 8 cm discs: ISO standards still regard these discs as Types A–D, while

6528-442: The format; for example the sentence to "watch a DVD" describes watching a movie on DVD. Released in 1987, CD Video used analog video encoding on optical discs matching the established standard 120 mm (4.7 in) size of audio CDs. Video CD (VCD) became one of the first formats for distributing digitally encoded films in this format, in 1993. In the same year, two new optical disc storage formats were being developed. One

6624-456: The ground up. By the beginning of the 2020s, sales of DVD had dropped 86% with respect to the peak of DVD sales around 2005, while on-demand sales and, overall, subscription streaming of TV shows and movies grew by over 1,200%. At its peak, DVD sales represented almost two thirds of video market in the US; approximately 15 years later, around 2020, they fell to only 10% of the market. By 2022, there

6720-792: The highest capacity of an individual disc that would be achievable using overburning , without writing any data to the disc. Few optical drives allow simulating a FAT32 flash drive from optical discs containing ISO9660 / Joliet and UDF file systems or audio tracks (simulated as .wav files ), for compatibility with most USB multimedia appliances. Optical drives for computers come in two main form factors: half-height (also known as desktop drive ) and slim type (used in laptop computers and compact desktop computers ). They exist as both internal and external variants. Half-height optical drives are around 4 centimetres tall, while slim type optical drives are around 1 cm tall. Half-height optical drives operate upwards of twice

6816-479: The innermost zone and then progressively increase the speed in several discrete steps up to 52× at the outer rim. Without higher rotational speeds, increased read performance may be attainable by simultaneously reading more than one point of a data groove, also known as multi-beam , but drives with such mechanisms are more expensive, less compatible, and very uncommon. Both DVDs and CDs have been known to explode when damaged or spun at excessive speeds . This imposes

6912-406: The large files used since the days of floppy disks, and the vast majority of computers and much consumer entertainment hardware have optical writers. USB flash drives , high-capacity, small, and inexpensive, are suitable where read/write capability is required. Disc recording is restricted to storing files playable on consumer appliances ( films , music, etc.), relatively small volumes of data (e.g.

7008-422: The laser beam is focused as a small laser spot on the disc. The second servo moves the pickup head along the disc's radius, keeping the beam on the track , a continuous spiral data path. Optical disc media are 'read' beginning at the inner radius to the outer edge. Near the laser lens, optical drives are usually equipped with one to three tiny potentiometers (usually separate ones for CDs , DVDs , and usually

7104-402: The light reflected from the disc's surface. Initially, CD-type lasers with a wavelength of 780 nm (within the infrared) were used. For DVDs, the wavelength was reduced to 650 nm (red color), and for Blu-ray Disc this was reduced even further to 405 nm (violet color). Two main servomechanisms are used, the first to maintain the proper distance between lens and disc, to ensure

7200-416: The lower spindle away from the upper spindle and vice versa when the tray is closed. When the tray is closed, the lower spindle touches the inner circumference of the disc, and slightly raises the disc from the tray to the upper spindle, which is attracted to the magnet on the lower disc, clamping the disc in place. Only the lower spindle is motorized. Trays in half height drives often fully open and close using

7296-464: The manufacturing process the tracks are formed by pressing a thermoplastic resin into a nickel stamper that was made by plating a glass 'master' with raised 'bumps' on a flat surface, thus creating pits and lands in the plastic disk. Because the depth of the pits is approximately one-quarter to one-sixth of the laser's wavelength, the reflected beam's phase is shifted in relation to the incoming beam, causing mutual destructive interference and reducing

7392-428: The notable inclusion of the 1996 film Twister . However, the launch was planned for the following day (March 25), leading to a distribution change with retailers and studios to prevent similar violations of breaking the street date . The nationwide rollout for the format happened on August 22, 1997. DTS announced in late 1997 that they would be coming onto the format. The sound system company revealed details in

7488-451: The original film recordings. Shows that were made between the early 1980s and the early 2000s were generally shot on film, then transferred to video tape, and then edited natively in either NTSC or PAL; this makes high-definition transfers impossible, as these SD standards were baked into the final cuts of the episodes. Star Trek: The Next Generation was the only such show that had a Blu-ray release, as prints were re-scanned and edited from

7584-454: The outer rim and 500 RPM on the inner, keeping the data rate constant. Later CD drives kept the CLV paradigm, but evolved to achieve higher rotational speeds, popularly described in multiples of a base speed. As a result, a 4× CLV drive, for instance, would rotate at 800-2000 RPM, while transferring data steadily at 600 KiB/s, which is equal to 4 × 150 KiB/s. For DVDs, base or 1× speed

7680-399: The preferred abbreviation DVD would be understood to denote digital versatile disc." The OED also states that in 1995, "The companies said the official name of the format will simply be DVD. Toshiba had been using the name 'digital video disc', but that was switched to 'digital versatile disc' after computer companies complained that it left out their applications." "Digital versatile disc"

7776-407: The process and returning to its normal shape after removal. The outer rim of the spindle may have a texturized silicone surface to exert friction keeping the disc from slipping. In slim drives most if not all components are on the disc tray, which pops out using a spring mechanism that can be controlled by the computer. These trays cannot close on their own; they have to be pushed until the tray reaches

7872-475: The reading speed based on the contents of optical discs, such as max. 40× CAV (constant angular velocity) for the Digital Audio Extraction ( “DAE” ) of Audio CD tracks, 16× CAV for Video CD contents and even lower limitations on earlier models such as 4× CLV ( constant linear velocity ) for Video CDs . Current optical drives use either a tray-loading mechanism, where the disc is loaded onto

7968-409: The reflected beam's intensity. This is detected by photodiodes that create corresponding electrical signals. An optical disk recorder encodes (also known as burning, since the dye layer is permanently burned) data onto a recordable CD-R , DVD-R , DVD+R , or BD-R disc (called a blank ) by selectively heating (burning) parts of an organic dye layer with a laser. This changes the reflectivity of

8064-412: The sales of DVDs and Blu-rays for the first time. Until the end of the 2010s, manufacturers continued to release standard DVD titles as of 2020 , and the format remained the preferred one for the release of older television programs and films. Shows that were shot and edited entirely on film, such as Star Trek: The Original Series , could not be released in high definition without being re-scanned from

8160-414: The same side—instead of proposal SD 10, which would have created a two-sided disc that users would have to turn over. Philips/Sony strongly insisted on the source code, EFMPlus , that Kees Schouhamer Immink had designed for the MMCD, because it makes it possible to apply the existing CD servo technology. Its drawback was a loss from 5 to 4.7 Gbyte of capacity. As a result, the DVD specification provided

8256-438: The same slot-loading drive. Its successor's slot drive however, the Wii U , lacks miniature disc compatibility. There were also some early CD-ROM drives for desktop PCs in which its tray-loading mechanism will eject slightly and user has to pull out the tray manually to load a CD , similar to the tray ejecting method used in internal optical disc drives of modern laptops and modern external slim portable optical disc drives. Like

8352-663: The slightly lower data density of dual layer DVDs (4.25 GB instead of 4.7 GB per layer), the required rotation speed is around 10% faster for the same data rate, which means that the same angular speed rating equals a 10% higher physical angular rotation speed. For that reason, the increase of reading speeds of dual layer media has stagnated at 12× ( constant angular velocity ) for half-height optical drives released since around 2005, and slim type optical drives are only able to record dual layer media at 6× (constant angular velocity), while reading speeds of 8× are still supported by such. The quality and data integrity of optical media

8448-427: The specification to support BD-J. Starting on October 31, 2007, all new players are required to have hardware support for the "Bonus View" features, but the players may require future firmware updates to enable the aforementioned features. "BD Live" support is always optional for a BD player. Sony's PlayStation 3 has been the de facto leader in compliance and support of BD-J, adding Blu-ray Profile 1.1 support with

8544-544: The speeds as slim type optical drives, because speeds on slim type optical drives are constrained to the physical limitations of the drive motor's rotation speed (around 5000 rpm ) rather than the performance of the optical pickup system . Because half-height demand much more electrical power and a voltage of 12 V DC, while slim optical drives run on 5 volts, external half height optical drives require separate external power input, while external slim type are usually able to operate entirely on power delivered through

8640-416: The total nominal capacity of a DVD-10 disc to 9.4 GB (8.75 GiB), but each side is locked to 4.7 GB. Like DVD-5 discs, DVD-10 discs are defined as single-layer (SL) discs. DVD hardware accesses the additional layer (layer 1) by refocusing the laser through an otherwise normally-placed, semitransparent first layer (layer 0). This laser refocus—and the subsequent time needed to reacquire laser tracking—can cause

8736-412: The tray. It can however only be used in horizontal operation. Slot loading drives, frequently used in game consoles and car radios, might be able to accept 8 centimetre discs and center the disc automatically. Optical discs are used to back up relatively small volumes of data, but backing up of entire hard drives, which as of 2015 typically contain many hundreds of gigabytes or even multiple terabytes,

8832-430: The ubiquitous VHS tape as the primary consumer video distribution format. Immediately following the formal adoption of a unified standard for DVD, two of the four leading video game console companies ( Sega and The 3DO Company ) said they already had plans to design a gaming console with DVDs as the source medium. Sony stated at the time that they had no plans to use DVD in their gaming systems, despite being one of

8928-413: Was an increased demand of high definition media, where Ultra HD Blu-ray and regular Blu-ray formats made up for almost half of the US market while sales of physical media continued to shrink in favor of streaming services. Longevity of a storage medium is measured by how long the data remains readable, assuming compatible devices exist that can read it: that is, how long the disc can be stored until data

9024-467: Was invented and developed in 1995 and first released on November 1, 1996, in Japan . The medium can store any kind of digital data and has been widely used to store video programs (watched using DVD players ), software and other computer files. DVDs offer significantly higher storage capacity than compact discs (CD) while having the same dimensions. A standard single-layer DVD can store up to 4.7 GB of data,

9120-802: Was the Multimedia Compact Disc (MMCD), backed by Philips and Sony (developers of the CD and CD-i ), and the other was the Super Density (SD) disc, supported by Toshiba , Time Warner , Matsushita Electric , Hitachi , Mitsubishi Electric , Pioneer , Thomson , and JVC . By the time of the press launches for both formats in January 1995, the MMCD nomenclature had been dropped, and Philips and Sony were referring to their format as Digital Video Disc (DVD). On May 3, 1995, an ad hoc , industry technical group formed from five computer companies (IBM, Apple, Compaq , Hewlett-Packard , and Microsoft) issued

9216-483: Was wasted, a head had to transfer data at a maximum linear rate at all times too, without slowing on the outer rim of the disc. This led to optical drives—until recently—operating with a constant linear velocity (CLV). The spiral groove of the disc passed under its head at a constant speed. The implication of CLV, as opposed to CAV, is that disc angular velocity is no longer constant, and the spindle motor needed to be designed to vary its speed from between 200 RPM on

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