Sony DVP S530D Bedienungsanleitung PDF herunterladen (Seite 58)

Disc Identification

DVD Player models DVP-S330, S530D, S550D and S705D identify the

disc during focus search as the laser’s objective lens is rising. Photo

detector group A-D in the optical assembly is used for this detection pro-

cess. These detector outputs are matrixed by the RF amplifier IC001 to

produce several outputs. Two signals are used to identify one of four

discs placed in the player.

Mirror – Voltage created when the light returned from the disc exceeds a

threshold. The light is the strongest when focus is near.

Focus Error – Identifies the exact point of focus. The point of focus will

occur within the window created by the MIRROR signal.

The Mirror signal is used for disc detection. The focus error signal is used

to verify that the mirror signal is a valid one.

Operation

During focus search, the laser’s objective lens is instructed to move up

and down while light reflected back from the disc is analyzed. As the lens

moves up during focus search, so does its corresponding focus point.

Light is first returned when the focus point arrives at the bottom of the

disc. This creates the first voltage (disc entry) at the mirror output. A

second voltage occurs when the information layer is found. A third volt-

age occurs if there is a second information layer. The time between the

voltages determines the disc type.

For example, in a DVD disc the information layer is closer to the bottom of

the disc than a CD. Therefore in a DVD, the second mirror signal will

occur sooner than in a CD where the layer is further away.

This disc ID information is initially used to determine the rough speed of

the disc. Finally, the disc type is authenticated during playback when the

digital data reveals the disc type.

Therefore the first full upward travel of the lens during focus search will

identify the disc type.

SACD Disc Type

SACD stands for Super Audio Compact Disc. Although this DVD player

can detect the SACD disc, it can only play its normal CD layer (number

two). The first layer can contain six channels of uncompressed audio and

a PCM audio track. At this time the SACD disc is only available in Japan.

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Sony DVP S530D Bedienungsanleitung Seite 58