Sony UP-21MD Service Manual page 57

(5) HD generation circuit
The HD signal output from pin 37 of IC204 is adjusted to the proper phase and pulse width by IC207
(monostable multivibrator) and sent to the frame memory block as an HD (horizontal sync) signal for
fetching memory. AFC (Automatic Frequency Control) processing is performed for this HD signal.
AASY-I
a)
10207 (173)
MC74HC4538AFEL
R245.
1€208 1/3) 2.7
WC74HC4S38AFEL
16208 (2/3)
NC74HC4538AFEL
Fig.1-5 HD Generation Circuit
(6) Demodulation axis correction circuit
Since, in a television circuit (IC204) for the consumer, the demodulation axis is not orthogonal for
NTSC, a matrix circuit (R241 to R249) is inserted into an RGB signal line so as to correct the
_ demodulation axis to an orthogonal axis. For PAL, the demodulation axis is orthogonal.
Demodulation is not related when an RGB signal is selected. In this case, therefore, the matrix circuit
must be turned off. The matrix circuit is switched to ON or OFF by IC206 and IC210.
Cvrce fovea)
T7880
~B8, O10-M5,
0206
OTC124EKA-1146
009-88 0)
BS
Fig. 1-6 | Demodulation Axis Correction Circuit
UP-2iMD V1 4-19