![background image](http://html.mh-extra.com/html/lg/gsa-4166b/gsa-4166b_service-manual_211208031.webp)
35
3) Recording format using phase-change recording material (DVD-RW/DVD+RW)
* Data is recorded by changing the recording layer from the amorphous status to the crystalline status, and
played back by reading the difference of the reflection coefficient.
[ Amorphous : Non-crystalline ]
Substrate
Laser beam
Recording data
(Melting/Quick cooling)
Erasing data
(Heating/Gradual cooling)
Data erased state
(High reflection coefficient)
Recorded state
(Low reflection coefficient)
Crystalline status
Amorphous status
DVD-RW
Adhesive layer
Protective layer
Reflective layer
Dielectric layer
Recording layer
(Phase change material)
Dielectric layer
Disc substrate
DVD+RW
Adhesive layer
Protective layer
Reflective layer
Dielectric layer
Recording layer
(Phase change material)
Dielectric layer
Disc substrate
> Disc structure
> Recording principles
[Recording]
When a high-power laser is applied to the recording material, it melts and then becomes amorphous with
a low reflection coefficient when it quickly cools off. When a mid-power laser is applied to heat gradually
the recording material and then gradually cools it off, it becomes crystal with a high reflection coefficient.
[Playback]
A low-power laser is used for playback. The amount of reflected light depends on the status (amorphous
or crystalline) of the recording material. This is detected by an optical sensor.
Содержание GSA-4166B
Страница 18: ...2 2 Pick up A Release 1 screw C and remove the Pick up Pick up Unit Pick up C Fig 2 2 18 ...
Страница 39: ...43 3 MD Assy For LightScribe Optical Encoder Unit OPU ID Movement Range L 21um ...
Страница 86: ...90 CD Laser Power Setup Result HC_CD Laser Power Setup Result DVD Laser Power Setup Result ...