Compact Disk (CD)[7]
- Introduction
- CD Drive: basic design
- Compact disk (CD): basic design
- Data encoding
- Making CDs
- Spin rates and Data transfer rates
- Interfaces
- Multi-beam technology
- White Papers on compact disk technology
-
Get a Optical Media Data Recovery Quote
TrueX Multibeam CD / DVD technology
Traditional CD and DVD drives employ a single laser beam directed at one track which forms a continuous spiral on the disc.
Instead of illuminating a single track on the surface of a CD-ROM or DVD-ROM disks, the technology, proposed by Zen Research illuminates multiple tracks, detects bits simultaneously, and reads them in parallel. This technology can be used without changes to the CD or DVD disk standards or basic drive design, and works with both CAV (Constant Angular Velocity) and CLV (Constant Linear Velocity, preferred by Zen to deliver constant data transfer rates across the disk). Multibeam technology at CLV enables optical drives to read and transfer data from the disc at a constant speed, which corresponds to the drive's true spin X-rating.
Increase in the data rates due to the multi-beam approach allows to reduce disk spin rates, and decrease associated with high speed vibration and noise.
The TrueX Multibeam method uses a conventional laser beam sent trough a diffraction grating which splits the beam into seven evenly spaced beams. These beams illuminate seven different tracks simultaneously. On their way to the disk surface, beams pass through a beam splitting mirror to the objective lens and towards the disk surface. Focus and tracking are performed using the central beam. Three beams on each side of the central beam are readable by a detector array if the center beam is in focus and on the track. On the way back, the reflected beams reach the multiple beam detector array, which consists of seven discrete detectors - one for each beam.
By reading seven tracks at once, the TrueX Multibeam drive achieves much higher data transfer rates than a conventional drive spinning at the same rate. Similarly, the TrueX Multibeam drive, operating at lower speed, can achieve the same data rate as a conventional drive and keep vibration and noise at much lower level.
Currently, Kenwood Technologies Inc., a subsidiary of Kenwood Corporation, offers a Zen-enabled TrueX Multibeam CD-ROM drives.
