Pioneer CX-3195 Instrukcja serwisowa - Strona 13

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1.2.4 Spindle servo system

In the spindle servo system, the following modes are available:

1) Kick

Used to accelerate the disc rotation in the setup mode.

2) Offset

a. Used in the setup mode after the kick mode, until the TBAL adjustment is completed.

b. Used during the play mode when the focus loop is unlocked, until it is locked again.

In both cases, the mode is used to keep the disc rotation approximately normal.

3) Applicable servo

CLV servo mode, used in the normal operation.

In the EFM demodulation block, by WFCK/16 sampling whether the frame sync signal and the internal frame counter

output are synchronized, a signal is created to show if they are "in-sync" or "non-sync." The status is not recognized as

asynchronous until the signal is "non-sync" for eight consecutive times; otherwise it is recognized as synchronous. In the

applicable servo mode, the leading-in servo mode is automatically selected in the asynchronous status, and the normal

servo mode in the synchronous status.

4) Brake

Used to stop the spindle motor.

In accordance with the CPU of the LSI command, the brake voltage is sent out from the servo LSI. At this time, the EFM

waveform is monitored in the LSI, and when the longest EFM pattern exceeds a certain interval (or the rotation slows

down enough), a flag is set inside the CD of the LSI, and the CPU of the LSI switches off the brake voltage. If a flag is not

set within a certain period, the CPU of the LSI shifts the mode from the brake mode to the stop mode, and retains the

mode for a certain period of time. If the mode switches to this stop mode in the eject operation, the disc will be ejected

after the period of time mentioned above elapses.

5) Stop

Used when the power is turned on and during the eject operation. In the stop mode, the voltage in both ends of the spindle

motor is 0 V.

6) Rough servo

Used in carriage feed (carriage move mode such as long search).

By obtaining the linear velocity from the EFM waveform, the "H" or "L" level is input to the spindle equalizer. In the test

mode, this mode is also used for grating confirmation.

IC201 PE5547A

EFM

SIGNAL

Fig.1.2.9 Block diagram of the spindle servo system

SPEED ERROR SIGNAL

PWM

DSP

DIG.

BLOCK

PHASE ERROR SIGNAL

CX-3195

IC301 BA5839FP

SOP

112

SOM

SPINDLE

MOTOR