Toshiba e-studio281c, Service Manual, Page: 150 / 414

e-STUDIO281c/351c/451c © 2005 - 2008 TOSHIBA TEC CORPORATION All rights reserved
SCANNER
6 - 6
6.4.2 Scanning drive circuit
The scan motor (M1) is a 2-phase stepping motor and driven by the driver IC (STK-672-400).
Fig. 6-7
Input/output signals
Clock input SCNCLK Inpu
t
Motor is rotated by setting number of pulse.
* Internal circuit of the motor driver works when the
first pulse becomes ON and the last pulse
becomes OFF.
Set the direction of
motor rotation SCNDIR Inpu
t
The direction of the motor rotation is determined by
setting level of signal.
“L”..... Clockwise direction (as seen from the output
shaft)
“H” .... Counterclockwise direction (as seen from the
output shaft)
Cut off the drive out-
put SCNEN Inpu
t
Excitation drive is forcibly turned ON/OFF.
“H” .... Normal operation (Excited)
“L”..... Excitation drive is forcibly shut off (Not excited)
Voltage to set value
for the motor current SCNREF Inpu
t
Motor wire current value is set in the range of 0 to 2.0
(A)/phase by applying the analog voltage 0 to 5 (V).
Set the exicitation for
the motor current SCNMD1 to 3 Inpu
t
Set the excitation mode.
Reset RESET Inpu
t
Reset for the whole system
Internal circuit of the driver is initialized by setting the
motor to “L” level.
The motor drive circuit is automatically reset when the
power is turned ON.
SLG board
Driver IC
Scan motor
Switching
regulator
M
GND
B
+24V
B
A
+24V
A
+24V
DG
SCNEN
SCNDIR
SCNRST
SCNREF
SCNMD3
SCNMD2
SCNMD1
SCNCLK
GND
+5V
H.OFF-0
CWCCW-0
MOTRST
SCNVREF
SMDT2-1
SMDT1-1
SMDT0-1
SCCLK-0
Cut off output
Rotation direction setting
Reset
Voltage to set value for motor current
Excitation mode setting-3
Excitation mode setting-2
Excitation mode setting-1
Clock input
RESET IC
Scanner
CPU
+
-
GND
+24V
+5V