Sony DVP-M35 Operation Manual

Also see for DVP-S300: Operating instructions Operating instructions Operating instructions Service manual Training manual

3-5. Differentiation of Disc TypeThis series can determine three types of discs (CD/DVD-SL/DVD-DL) at one timewhen performing focus-search.3-5-1. CD/DVD DifferentiationThe pit shape and track pitch are quite different between CD and DVD. Because of thisdifference, TE is not generated even if a large laser spot for CD is shot at a high densitydisk 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 theCD side), TE is not generated almost all.On the other hand, by playing CDs in the CD mode, naturally, the 2Vp-p traversewaveform (approx.) will be measured. This is used for the detection.3-5-2. SL/DL DifferentiationSL/DL is differentiated by the PI level.3-5 -3.1)2)3)4)5)6)7)DifferentiationThe 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 ONThe spindle turns ONThe 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 levelof the DVD is measured at the same time.• IC805 SH (system controller) reads the TE and PI levels measured bythe DSP todifferentiate 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 traversewaveform.CD __h_ I Approx. 2Vp-pSL/DL differentiation: The PI level becomes SL>DL.• _ ' I Approx.1VSLOVO ----.... -Figure. 3-20. Traverse waveformDLFigure. 3-21. PI waveform,rox.0.5V- 52 -