Abbingdon Music Research Compact Disk Processor CD-77 - Manual (Page 35)

35
Maintenance
i. About the Optical Pickup
The CD-77 uses a solid-state semi-conductor diode laser, mounted on a tracking servo-mechanism to play the
disc. The laser illuminates the track of microscopic pits representing the digital data bits, while photo-diodes
detect the reflected illumination from the disc and convert it into an electronic signal which is then decoded to
recover the musical waveform in each stereo channel. It is not possible to see the laser operating, because it
operates at wavelength of 7800 Angstroms, which is in the infrared and thus invisible to the human eye.
The compact disk processor is completely safe for children to use. The laser operates at very low power and is
concealed within the CD-77’s mechanism. Even when the CD-77 is disassembled, the laser remains sealed
within an optical system that causes its light to focus only 1 millimetre from the lens and then diverge rapidly,
reducing its intensity to negligible levels.
CLASS 1 LASER PRODUCT
No User Serviceable Components Inside
.
For service contact your Authorised
Dealer or Distributor
Any modifications to this equipment will
void all warranties ,
.
.
ii. Factors that affect Playability
The quality of the compact disc itself and that includes the fact there should not be too many scratches on the
surface. Generally speaking, CD-R & CD-RW blanks from well-renowned companies give better results than
unbranded ones.The quality of CD-recorder or computer CD re/writer: some recorders and writers produce
better results than others.
Although the CD-R & CD-RW is typically created using high-speed writing, in general, the quality of a CD-R &
CD-RW is better when recorded at a lower speed against a higher speed on the same recorder or re/writer.