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2.2.6
PRINT CYCLE INITIALIZATION
To confirm that carriage is in stand-by status (at the
first column), initialization must be performed prior to
printing and paper feeding. Initialization is completed
by performing a line feed. The following paragraphs
describe printer timing operations for printing and
paper feeding.
Printing of the first line
1) The Timing pulses TP are counted after the motor
drive signal is applied and the motor is activated.
The reset pulse RP appearing after eight timing
pulses is regarded as RPo, and the first timing
pulse TP after RPo rises is regarded as TPo.
2) Character selection (first column)
The trigger coil drive pulse is applied to the trigger
coil during the interval from timing pulse TPn to
TPn + 1 which corresponds to the desired charac-
ter. At that time, the timing pulse interval (TPn to
TPn +1) is measured to obtain TW1. Following
character selection, the print wheel stops (the
timing pulse retains the TPn + 1 status). Printing
and carrying are then automatically executed.
3) Character selection (second column and onward)
The print wheel starts rotating again and the first
timing pulse is TPn +2. Character selection can be
performed from next timing pulse TPn + 3. The
rest of the character selection operation is iden-
tical to that described in step 2) above.
4) Carriage return and paper feeding
During character selection for the highest-order
column of a line of print, printing, carriage return,
and paper feeding are performed by adding: [the
width of the drive pulse to the trigger coil] + [the
timing pulse interval TW2 (TPn to TPn + 1) at that
time] + [(the TP interval TW1 measured during the
selection of the first column) x 6].
5) Motor off
After completing the highest order printing in one
line, the print wheel begins to rotate and timing
pulse TP is generated. Counting from this initial
rising pulse, the motor drive signal is cut off at the
rise of the 14th timing pulse TP.
NOTE:
•
The first timing pulse generated after the print
column-shift process (TPn + 2) cannot be used for
character selection.
2-12
Consecutive printing
1) The process for printing the initial line similar to
that for "Printing the first line" above.
2) Printing of second and later lines begins as
follows:
After printing the first line, the following pulses TP
are counted with the motor still driven. Printing of
the first column of the second line then begins at
the rise of the 14th timing pulse in cases where the
number of columns in the first line is 7 or less,
otherwise, printing begins at the 21st timing pulse.
The same procedures as those in steps 2) to 4) of
"Printing the first line" above are then performed.
3) Consecutive printing is performed by repeating
step 2) above.
4) Motor off
Step 5) of "Printing the first line" above is per-
formed.
Paper feeding for the first line
1) The timing pulses TP are counted after the motor
drive signal is applied and the motor is activated.
The reset pulse RP appearing after eight timing
pulses is regarded as RPo, and the first timing
pulse TP after RPo rises is regarded as TPo.
2) Paper feeding
The empty character TP10 is selected. At that
time, the timing pulse interval TP10 to TP11 is
measured to obtain TW1. When the width of the
trigger coil drive pulse equals the measured TW1
plus six times TW1, the empty character on the
print wheel is selected and the paper is fed.
3) Motor off
After the paper is fed for one line, the print wheel
begins to rotate. Counting from the initial rising
timing pulse, the motor drive signal is cut off at the
rise of the 14th timing pulse TP.
Fast paper feeding
1) The process for feeding the initial line is similar to
that for "Paper feeding for the first line" above.
2) Paper feeding for the second and later lines begins
as follows: after completing the paper feeding for
the first line, with the motor remaining driven, the
following timing pulses TP are counted. From the
rise of the 21st timing pulse, selection of the empty
character TP10 becomes possible. Step 2) of
"Paper feeding for the first line" above is then
performed.
3) Fast paper feeding is performed by repeating step
2) above.
4) Motor off
Step 3) of "Paper feeding for the first line" above
is performed.
Service Manual
686770R
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