Sony UP-890MD - Page 45

Here are the terminal states for each mode.
PM FW/PM CW MS2
STOP H
3:4 L
1:1 H
Fast forward H
Rewind H
* Note: Since INT-V is made by counting down the FG frequency for the motor
servo, if the motor is not turning, it is not output.
(iv) When the platen motor is turning and the FG pulses are input to 1C103-@,@,
INT-V is output from IC301-@, and input to 1C301-@. Within 1IC301,
INT-V is measured for about 10 to 20 pulses to ensure that INT-V has a fixed
pulse width. After verifying that the pulse period is 4 to 24 msec, the system
moves to the next screen operation.
{1] From INT-V pulse measurement to screen printing
INT-V
1C€301-@ l I I I I I l
COPY
1€301-©)
COPY TIMING : '
COPYING
1C301-@
COPY OPERATION INSTRUCTION
| 66 pulse «> 1-LINE SCREEN PRINTING TIMING
STB
I
a
SCREEN PRINTING DATA COPY TIMING | 1-INT-V |
DR
1€301-9)
SERIE:
Ot*:*=<“<—~SC:C(<i«é‘“—C
I
Fig.5-6. Screen Printing Timing
Operation
(i) When the platen motor rotation is stabilized and the INT-V period is stable, the
COPY pulse is output to IC301-@ synchronized with INT-V.
(ii) When the COPY pulse is input to 1C301-@), IC103 outputs the COPYING pulse
from its pin @ to IC301-@ to tell it that IC103 is standing by for screen
printing.
(iii) When 1C301 verifies that COPYING is “L”, it ouptuts STB and DR. The
screen printing timing is set by these signals.
*Note: If the period of INT-V fluctuates too greatly during screen printing,
printing is stopped.
2255 —