Computer artwork showing light emitted by a laser diode being focussed onto a compact disc by a small lens. The metal disc underneath is etched by a laser beam to produce the microscopic pits which carry the digital code representing sounds. The code is read by a laser reflecting the pits of the etched surface back through the lens onto a sensor in a CD player which converts the signal back into music. To reflect the laser light,the music layer is coated with a fine film of metal which follows the depressions exactly. Each depression is either long or short,each representing a bit. Eight bits form a byte. CDs can hold millions of bytes of data. DVDs can hold billions of bytes of data. The data track is about 0.5 micrometres wide,and is several kilometres long | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Parker, David |
Taille de l’image : | 5332 px × 3500 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |