Optical storage devices

Transcription

1 Trabajo 4.6: Optical storage devices Konrad Polek Periféricos e Interfaces Ingeniería en Informática Curso

2 Agenda Introduction Optical technology CD and DVD CD-Based optical technology Brief history Construction and Technology Manufacturing Drives Capacity Other optical technology standards Blu-ray, HD-DVD Optical Storage Devices 2

3 Optical Technology Two types of disk storage for computers magnetic optical Optical disc storage is similar to magnetic disk storage in basic operation, but it reads and records using light(optically) instead of magnetism. Many optical storage media are read-only or write-once. Using for backup, archival storage purpose and as a mechanism by which programs or data can be loaded onto magnetic drives. Optical Storage Devices 3

4 Optical Technology Rewritable DVD drives - truly high-capacity optical medium. All systems today have an optical drive of some type, and most have support for both DVD-ROM and CD-RW. Optical technology standards: CD (CD-ROM, CD-R, CD-RW) DVD (DVD-ROM, DVD-RAM, DVD-RW, DVD-R, DVD+RW, DVD+R) Blu-ray HD-DVD others Not only computer use Optical Storage Devices 4

5 Agenda Introduction Optical technology CD and DVD CD-Based optical technology Brief history Construction and Technology Manufacturing Drives Capacity Other optical technology standards Blu-ray, HD-DVD Optical Storage Devices 5

6 CD-Based Optical Technology CD-ROM compact disc read-only memory based on the original CD-DA (digital audio) Writable CD-R and CD-RW. CD-ROM properties: 120mm diameter, 1.2mm thick plastic disc 74 or 80(newer) minutes of high-fidelity audio 650MiB (682MB) / 700MiB (737MB) data stored on one side (only bottom is used) Optical Storage Devices 6

7 CDs: Brief History In 1979, Phillips and Sony cooperated to produce the CD-DA standard. Phillips laserdisc players, Sony recording research. In 1980, the CD-DA standard is announced (Red Book). October 1, 1982 Sony introduced first player and commercial CD album. In 1984, Sony also introduced the first automobile and portable CD players. In 1983, CD-ROM standard (Yellow Book). Optical Storage Devices 7

8 CD-ROM Construction and Technology CD-ROMs looks identically like CD-DAs but it stored data instead of audio. CD-ROM drives in PCs are almost identical to audio CD players. Main change: added error detection and correction (to ensure data is reading without errors, because there is difference between missing data in file and error in a song). Optical Storage Devices 8

9 CD-ROM Construction and Technology A CD is made of a polycarbonate wafer, stamped or molded with a single physical track. Optical Storage Devices 9

10 CD-ROM Construction and Technology Track in a spiral configurations starting from the inside of the disk and spiraling outward (counterclockwise). Raised bumps pits Flat areas lands Optical Storage Devices 10

11 CD Manufacturing Process Method of recording data: track, pits and lands. Commercial mass-produced CDs are stamped. Not burned by a laser! Optical Storage Devices 11

12 CD-ROM drive Optical Storage Devices 12

13 How data is written Data Encoding on the Disc: EFM (Eight to Fourteen Modulation) 1B (8b) -> 14-bit value for storage RLL 2,10 (Run Length Limited) Never fewer than 2 or more than 10 adjacent 0 bits. 3T, 11T minimum and maximum distance between 1s. Merge bits 3b added between each 14-bit EFM value Optical Storage Devices 13

14 How data is written EFM table: Optical Storage Devices 14

15 How data is written Example: Optical Storage Devices 15

16 How data is reading Optical Storage Devices 16

17 DVD standard In 1996, DVD-ROM and DVD-Video standards were officially announced. In simplest terms is a high-capacity CD. DVD uses the same optical technology as CD, with the main difference being higher density. DVD disc: 120mm diameter, 1.2mm thick plastic disc 4.7GB(single layer) / 8.5GB(dual layer) data can be stored on both side Optical Storage Devices 17

18 DVD Construction and Technology DVDs can have two layers of recording on a side and be double-sided as well. Each layer is separately stamped. Laser with a shorter wavelength, focused more closely to the disc. Optical Storage Devices 18

19 DVD Capacity (Sides and Layers) Optical Storage Devices 19

20 DVD Capacity (Sides and Layers) Optical Storage Devices 20

21 DVD Capacity (Sides and Layers) CD-ROM properties: 74 or 80(newer) minutes of high-fidelity audio 650MiB (682MB) / 700MiB (737MB) Optical Storage Devices 21

22 Caring for Optical Media Optical discs have no protection once they are removed from their storage case. The most common causes of problems with optical discs and drives are scratches, dirt, other contamination. Most fragile is top of the disc! Scratches on the top of the disc are more fatal than those on the bottom. Read errors can also occur when dust accumulates on the read lens of CD-ROM drive. Optical Storage Devices 22

23 Summary Optical discs are used to store audio, video and computer data (which can be information or computer programs). Music CDs are now the medium of choice for distribution of music albums. Similarly, DVDs have become standard for movie distribution, containing both audio and video, which have replaced the popular VHS videotape medium. They are losing popularity to other storage devices which have much faster data transfer rates, including USB flash drives and external hard drives. Optical Storage Devices 23

24 Agenda Introduction Optical technology CD and DVD CD-Based optical technology Brief history Construction and Technology Manufacturing Drives Capacity Other optical technology standards Blu-ray, HD-DVD Optical Storage Devices 24

25 Blu-ray Disc In February 2002, Blu-ray Disc specifications were announced. It s a high-capacity CD/DVD-type optical disc format. The Blu-ray Disc 1.0 formats (2002): BD-ROM (read-only for prerecorded content) BD-R (recordable for PC data storage) BD-RW (rewritable for PC data storage) The BD-RE format had been revised in 2006 (rewritable format for HDTV recording). The current specification is BD-RE 2.0. Optical Storage Devices 25

26 Blu-ray Disc Blu-ray uses 405nm blue-violet laser, which is shorter than the red one uses by CDs (780nm) and DVDs (650nm). Up to 2 hours of high-definition video (or more than 13 hours of standard broadcast-quality TV) on a single-layer disc. Optical Storage Devices 26

27 HD-DVD Another blue laser optical disc format. HD-DVD is similar to Blu-ray but not compatible. A dual-layer HD DVD holds a maximum of 30 GB of data, while a dual-layer Blu-ray carries 50 GB. Despite the bad performance had a certain advantage - the first layer of the media could be identical to the standard DVD layer. This ensured compatibility with DVD player at the first layer. Optical Storage Devices 27

28 HD-DVD Warner Bros. officially announced Total Hi Def (THD or Total HD) in THD hybrid discs were to support both HD DVD and Blu-ray, with HD DVD on one side (up to two layers) and Blu-ray on the other side (up to two layers). However, in November 2007 Warner Bros. cancelled THD development. In January 2008 Warner Bros. announced it would stop supporting HD DVD by June 2008, and the company would release HD titles only on Blu-ray Disc. Optical Storage Devices 28

29 Other optical media LD (LaserDisc) GD-Rom (Sega's DreamCast gaming system) MD (MiniDisc) SuperAudio-CD CBHD (China Blue High-definition Disc) 5D DVD (Five dimensional discs) NOD (Nintendo optical disc) And many others Optical Storage Devices 29

30 Thank you! THE END Optical Storage Devices