Data Storage Device

CD & DVD

Prepared By:-

Jerin Chacko

Vyas Pratik

AP

Index

• History

• Manufacturing

• Types

• Difference between CD & DVD

• Limits the Data on a CD/DVD

• HD-DVD v/s Blue Ray DVD

• First public demonstration of CD is in 1976 By Sony.

• High Quality Audio CDs have been commercially

available from October 1982 By Philips

• The VCD standard was created in 1993 by Sony, Philips,

Matsushita.

History

MANUFACTURING OF CD/DVD

Types

• CD (Compact Disc)

• DVD (Digital Video Disc)

• HD-DVD (High Defination – Digital Video Disc)

• BD (Blue ray Disc)

• CD

12 cm disk with plastics substrate, aluminum coating

and plastic cover

0.83 micron wide pits, 1.6 micron spacing

Data storage capacity 700 MB

Overall CD

• DVD

12 cm disk with plastics substrate, aluminum coating

and plastic cover

0.4 micron wide pits, 1.2 micron spacing

Data storage capacity 4.7 GB

Two sided, 2 levels/side top level partially reflecting

Increase to 8.5 GB (2 sided), 17 GB (2 levels, 2 sided)

Two levels of DVD

Diffrence

CD DVD

Capacity: 700 MB Capacity: 4.7 GB

Data Tran. Rate: 1.4-1.6

MB/Sec

Data Tran. Rate: 11 MB/Sec

Pits Length: 0.83 Micron Pits Length: 0.4 Micron

Distance b/w Disc Sur.-Data

Sur: 1.1mm

Distance b/w Disc Sur.-Data

Sur: 0.6mm

Disc Thickness: 1.2 mm Disc Thickness: 1.2 mm

Note:-

This is the Optic

which help to write data

on CD/DVD

Limits the Data on a CD/DVD

Each pit is one “bit” (0 or 1) of data

How fast the CD turns (1.4 m/sec for single speed)

Rotation speed limit: about 52x (72.8 m/sec)

Problem is lifetime of Blue laser approaching

1000 hrs

HD-DVD v/s Blue Ray DVD

• Next generation DVD format has two competitors

• HD-DVD: Toshiba, NEC, Microsoft, entertainment industry

• Blue Ray (BD): Sony, Hatachi, Panisonic, Apple etc

• Blue Ray higher capacity (25 GB) vs HD (15 GB)

• Hence shorter pits: Blue ray 0.16 μm, HD 0.205 μm

• Problem is that Blue ray is much nearer the surface (0.1 mm)

• Blue ray can have 8 layers, up to 200 GB, HD 4 layers, 60 GB

• Sept 2008 Blue ray only 8% of market, DVD 92%

REFERENCE SITES:-

WWW.WIKIPEDIA.ORG

WWW.DIGICOM.COM

THANK YOU….