Differentiation Of Disk Type; Cd/Dvd Differentiation; Sl/Dl Differentiation; Differentiation - Sony DVP-M35 Operation Manual
Cd/dvd player
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Also See for DVP-M35:
- Service manual (105 pages) ,
- Operation manual (79 pages) ,
- Operating instructions manual (50 pages)
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3-5. Differentiation
of Disc Type
This series can determine
three types of discs (CD/DVD-SL/DVD-DL)
at one time
when performing
focus-search.
3-5-1.
CD/DVD
Differentiation
The pit shape and track pitch are quite different between CD and DVD. Because of this
difference, TE is not generated even if a large laser spot for CD is shot at a high density
disk such as DVD. This feature is utilized to judge CD or DVD.
Specifically,
even if DVD is played in the CD mode (the optical pickup
operates at the
CD side), TE is not generated almost all.
On the other hand, by playing
CDs in the CD mode, naturally, the 2Vp-p
traverse
waveform
(approx.)
will be measured. This is used for the detection.
3-5-2. SL/DL Differentiation
SL/DL is differentiated by the PI level.
3-5 -3.
1)
2)
3)
4)
5)
6)
7)
Differentiation
The servo system mode is CD (MB-78 board: IC452 "(_)"P and "(_" are "L")
PI mode is DVD (MB-78 board: IC452 (_)P is "H")
Both lasers turn ON
The spindle turns ON
The sled is moved to the external circumference
slow.
Both focus actuators
are moved up and down.
The signal is measured.
IC506 DSP (CXD8730R)
• When the p-p value of the CD traverse
waveform
(24p) is measured,
the PI level
of the DVD is measured
at the same time.
• IC805 SH (system controller)
reads the TE and PI levels measured
bythe
DSP to
differentiate
between CD/DVD-SL/DVD-DL.
• CD/DVD
differentiation:
TE is generated
as a clear traverse waveform,
CD/DVD
differentiation:
Judged as CD if TE is generated
as a clear traverse
waveform.
CD __h_
I Approx. 2Vp-p
SL/DL differentiation:
The PI level becomes
SL>DL.
•
_
'
I Approx. 1V
SL
OVO
----.... -
Figure. 3-20. Traverse waveform
DL
Figure. 3-21. PI waveform
,rox.0.5V
- 52 -
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