The character position detecting signal (CP) is to be made by the user
from the leading edges of the set signal and reset signal. This CP
corresponds to the character on the character belt. The standard sig-
nal (SD) is a signal output once to the 75CP pulse, and the signal to
be made by the user utilizing the leading edge of the second CP from
the leading edge of this signal is the standard position signal (SP).
The reason why CP and SP are made using the raw signals output
from the detector is that the effect of chattering is taken into considera-
tion.
The following will explain the basic operation.
3-4. Operation Sequence
The basic operation is explained
(1) Initialization
In order to make sure that the hammer holder is at its home position,
i.e. the first column, print the space after power is turned on, and after
the carry / return, do one-line paper feeding and set the hammer
holder at its home position. This completes the initialization.
(2) 1-line printing operation
1) The printing operation is started by setting the motor driving signal
(MT) ON.
2) Prior to 1-line printing, detect the standard position signal (SP)
once and make the time from the leading edge of the character
position detection signal CP8 to the leading edge of CP9 to and
make it standard pulse width. (This to setting must be done at the
initialization and prior to the 1-line printing. to is utilized for error
detection.)
3) The character belt rotates until the desired CP pulse is detected.
4) If the desired CP pulse is detected, power is supplied to the elec-
tromagnetic clutch unit, the character belt is stopped, and printing
operation / carry operation are done. In the meantime, the power to
the electromagnetic unit is cut off. (For the detail, see 1.3.2.Printing
/ Carry Mechanism.)
5) After completion of the printing / carry operation, the character belt
rotates again.
6) The operations 3) through 5) are repeated and 1-line printing is
completed.
7) After the most significant digit printing, the electromagnetic clutch-
signal TM becomes OFF, and then between T3 and T4, paper
feeding / column return operation is done by turning the electro-
magnetic clutch ON again.
T3 = 80 to 200 msec
T4 = (2.0 ~ 2.4) x Tcp
8) After paper feeding is started, it is completed when about 19CP is
counted.
9) The motor driving signal is turned OFF after 19CP counting after
the paper feeding is started. In case SP is not found within 19CP
after the paper feeding is started, it is turned OFF after SP is
detected.
Fig. 5 Time Chart for 1-Line Printing (0. |___|* printing)
(3) Continuous printing operation
1) After the 1-line printing operation in (2), the motor driving signal
(MT) is not turned OFF and the operations 2) through 8) are con-
tinuously done for the necessary number of columns while the
motor is run.
2) After the most significant digit of the last line is printed, the opera-
tions 7), 8) and 9) in (2) are done and the motor is stopped.
(4) Paper feeding operation
For the paper feeding operation, 1-line printing of space may be done
in the same way as for the printing operation sequence.
3-5. Troubleshooting dislocated print belt
Install the character belt on the drive pulley and driven pulley. When
installing the character belt, the following points must be considered.
1) If the driven pulley is removed and mismatched with the CC cam, it
should be aligned as follows.
2) The character belt should be positioned as follows.
Manually turn the motor to the position where the SD pulse ap-
pears.
089 21 0
Motor driving signal(MT)
Standard pisition
detection signal(SP)
Character position
detection signal(CP)
Electromagnetic
clutch signal(TM)
Carry gear operation
Paper reeding operation
Rack operation
Hammer operation
Carry operation
Fig. 4 Time Chart at Initialization
089 17 232528 0
16 22 24 27
19CP(mim)
T4
T3
t0
0. *
Motor driving signal(MT)
Standard pisition
detection signal(SP)
Character position
detection signal(CP)
Electromagnetic
clutch signal(TM)
Carry gear operation
Paper reeding operation
Rack operation
Hammer operation
Carry operation
Printing pattern through
the adove operation
Boss of
frame
Hole
Driven pulley
Frame hole
(Driven hole
inserting part)
CC cam
