1-7
IM 704420-01E
Explanation of Functions
1
1.4
Acquisition Conditions for the Input Signal
Being Measured
Equalizing of RF Signals (Equalizer) «See 4.2 for the operating procedure»
You can equalize (compensate) the signal amplitude in the high frequency region.
The signal amplitude in the high frequency region attenuates due to the frequency
characteristics of the optical pickup. By passing the RF signal that is applied to the RF
input connector through the equalizer, we can obtain a signal that has frequency
characteristics that do not attenuate up to the high frequency region (better frequency
characteristics than the optical pickup).
Frequency
Frequency characteristics
of the signal applied to the
RF input connector
Frequency
Frequency characteristics
of the equalizer
Frequency
Frequency characteristics
of the signal after passing
through the equalizer
Amplitude
Amplitude
Amplitude
Binarization of the RF Signal
The binarized data signal of the RF signal is the signal used to measure the pulse width
and time difference. Using the slicer of the TA120E, the RF signal is binarized by setting
the portion of the signal that is greater than the given slice level* to the positive side and
the portion that is less than the slice level to the negative side.
*
The slice level changes depending on the trigger mode setting. For setting the trigger mode
and slice level, see “Trigger Level and Slice Level” described later.
Slice level
RF signal
Data signal
Auto slice
To compensate for asymmetric signal waveforms specific to the CD or DVD, the slice
level can be automatically detected so that the time ratio between the positive and
negative sides of the RF signal is 50% The RF signal is binarized using the detected
slice level. The auto slice function operates when the trigger mode is set to “auto
mode” or “auto + manual mode.”
Slice level
RF signal
Data signal
