1550/1560 DISPLAY
5 - 4
Mar. 1998 © TOSHIBA
5.4
LED Display Circuit
(1) LED display method
Described here is the LED for "dual-page copy-
ing" display when "DP" comes ON. When the
DSPON0 signal goes to "L" level, transistor Q2
is turned ON. When pin 7 of the IC (D15) goes
to "L" level, electrical current flows through the
transistor to the LED (DP) from +5V. In other
words the LED (DP) comes ON.
(2) The actual circuit is controlled as follows:
•
DSPON0 and DSPON1 signal goes to "L"
level alternatively for 8 msec.
•
Q1 or Q2 goes to the ON condition when
the DSPON0 or DSPON1 signal is at "L"
level.
•
The LED ON/OFF signal from LGC is in-
putted to the IC SIN (pin 5) terminal via the
DSPDAT signal (serial data).
•
LED ON/OFF signal is outputted in parallel
to D1-D16 output terminal, after being in-
putted to IC in series.
8 msec 8 msec
TR2
OFF
TR2
ON
ON
ON
ON
DSPON1
DSPON0
DSPDAT
D1
LED “00”
LED “01"
TR1
ON
TR1
OFF
+5V
R3
R4
Q2
G
(LP32)
R28
DSPON0
“L”
“L”
7
D15
PWA-PNL
Electrical
current
Summary of Contents for 1550
Page 11: ...1550 1560 GENERAL 2 4 Mar 1998 TOSHIBA ...
Page 112: ...1550 1560 DRUM 9 12 Mar 1998 TOSHIBA 1 16 48 CLK SI1 LT OUT1 1 2 64 Timing chart ...
Page 167: ...Mar 1998 TOSHIBA 13 25 1550 1560 OPTIONAL 13 7 4 PC board assembly PWA F PFU ...
Page 188: ...Mar 1998 TOSHIBA 14 21 1550 1560 CIRCUIT DIAGRAMS Control Panel Circuit PWA F PNL 4 4 ...
Page 189: ...1550 1560 CIRCUIT DIAGRAMS 14 22 Mar 1998 TOSHIBA 14 4 Fuser Circuit PWA F FUS ...
