Sharp VB-500/A/BG Service Manual page 12

B-500/A/BIG
4. SIMPLIFIED ADJUSTMENT PROCEDURES FOR CCD PWB WITHOUT USING AN
OSCILLOSCOPE
Caution
The procedures described below, simplified adjustment
methods may be used when the electronic white board
is, for instance, moved from one place to another and
requires readjustment. When conducting this adjust-
ment, be sure not to move the lens and the light volume
adjustment plate, readjustment of the Lens require the
use of an oscilloscope.
Never touch the red marked screws, since an oscillo-
scope is also required for their adjustment.
1. Adjustment of the Read-Out Range
Preparation
(1) Remove the rear cover and install the printer.
(2) Remove the front frame and turn on the power
switch. After the initial setting, select the 4th Frame.
(3) Draw horizontal lines with the marker at two posi-
tions, 35 mm from the upper and the lower ends of
the writing white sheet as shown in Figure 7.
(4) Loosen the screws @ and @' shown in Figure 9.
—
\
Main body
Stretch the chart of
Figure 13 like this way.
Read-out
position
Roll white sheet
Aluminum sash
Board position of first
Page white sheet
Figure 11
Brightened area due to
reflection of fluorescent lamp.
Adjust the reference line of
Figure 13 chart to this position.
Adjustment point
of Figure 13 chart.
12
Adjustment
(1) Make a copy of the 4th Frame and check that the
horizontal lines on the writing sheet are copied.
(2) When the lines are not copied, turn the hexagon nut
below the screw @) using the adjustment Tool while
making a copy of the 4th Frame.
This hexagon nut has endless turn construction,
which brings the nut Back to its initial position
when it is turned 360°. In making the adjustment,
therefore, turn this nut in one direction until the
point is found where both of the horizontal lines are
copied.
(3) Tighten the screws @ and @'. Make copy of the 4th
Frame again and check that the upper and the lower
horizontal lines are printed. Then apply screw-lock
to those screws to finish the adjustment.
2. Adjustment of the Read-Out Position
Preparation
(1) Remove the rear cover and install the printer.
(2) Attach the adjustment chart in such way that the
marks A-A shown in Figure 13 will come precisely
to the edges of the frame as shown in Figure 13-1.
(3) Attach the "BOARD" of the chart at the other side of
A-A marks to the inside of the aluminum sash while
avoiding slackness.
(4) Turn on the power switch and make initial setting.
Aluminum sash
White sh eet
Figuret 3 chart
Figure 12