Sony TVP-08, Training Manual

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The flowchart on the previous page shows the sequence of operations for
the Auto Focus operation. The first operation is to set the initial settings.
Then the H size is changed. This is done because the sensors are out-
side of the screen. After the H size is enlarged, a dark current measure-
ment is performed. This means that a reading of the sensors is taken
with output from the tube in order to establish a room brightness offset.
This measurement is subtracted from the readings taken later. After the
V centering and skew adjustments are performed for each color, the H
size is returned to normal and the V size is enlarged. A dark current
measurement is taken again and then H centering and skew adjustments
are done. When these adjustments are complete, V size is returned to
normal. If an error occurred, the process will be repeated. If the error is
returned a second time then an error code is given.
START
YES
YES
YES
NO
NO
NO
END
Measure 2V+2V
ROUGH
STEP
ADJUST
CENT
FINE STEP
ADJUST
SKEW
FINE STEP
ADJUST
Measure 4V+4V
Measure 4V+4V
Did CENT & SKEW
measurement exceed
center point?
4STEP change in CENT,
SKEW
Did CENT measurement
exceed center point?
1STEP change in CENT
Did SKEW measurement
exceed center point?
1STEP change in SKEW
The flowchart below left shows the steps taken during the adjustment
portion of the previous flowchart. As these adjustments are performed,
the convergence data values for centering and skew are changed for
each color. This data is measured until the data center point or optimum
value is measured. When this point is reached the system moves on to
the next step. If an error occurs the cycle repeats. If an error occurs the
second time then it puts an error code on the screen.
The error system works slightly differently in the Service Mode. If an error
occurs while running Auto Focus in the Service Mode, an error will be
displayed immediately instead of repeating the adjustment and displaying
the error when completely finished. An error like the one below shows the
type of error that would occur if the sensor 1 received a low output level
for blue.
ERROR CODE 10
ERROR
SENSOR NUMBER
R. G. B
E 11 B
E 11 B
* Error code will be displayed on center of screen for 3 seconds.