A-66
I n t e l l i T o u c h / S e c u r e T o u c h G u i d e
Since the gross function of the touchscreen is that of a switch, this characteristic
can be observed. Connect an ohmmeter between pin 3 and any of pins 1, 2, 4, or
5 of the touchscreen cable. This should show an open circuit (>1 megohm)
when the touchscreen is not being touched, and <1000 ohms when touched in
the middle of the touchscreen with firm finger pressure. A resistance of less than
5000 ohms will usually register a touch with a controller. Resistances up to 200
kilohms without a touch will cause linearity problems, as the touchscreen
system effectively averages a deliberate touch with the problem area. When
these low resistance values are observed, look for bezel contact in the active
area or damage to the cover sheet of the touchscreen.
If the bezel is touching, adjust the mounting. If damage is suspected, monitor
the resistance as described above while pulling gently on the cover sheet at the
damaged location with a piece of tape stuck to the touchscreen. The resistance
will increase to the normal open circuit value if the correct spot has been
identified. It is possible, in some circumstances, to correct touchscreen shorts
that result from damage to the cover sheet. Contact Elo Technical Support for
assistance.
There are additional resistance measurements that can reveal other problems.
Referring to Figure 2.1 on page 2-18, corner-to-corner touchscreen resistances
should be similar (within about 10%) between the following pins:
Most touchscreens will have resistances between 50 and 100 ohms. Also, the
resistances are usually proportional to the relative distances between the corners
for a particular size of touchscreen. Thus the H-Y and X-L readings are usually
larger than H-X and Y-L. Do not count on consistent resistance values from
touchscreen to touchscreen. In general, large variations in resistance pairs, or
absolute values above 120 ohms indicate a faulty touchscreen. Touchscreens
with this type of damage are not repairable.
1-2, 4-5
(H-X, Y-L)
1-4, 2-5
(H-Y, X-L)
Содержание AccuTouch 821615-000
Страница 3: ...4...
Страница 5: ...12...
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Страница 15: ...1 16 E l o E n t u i t i v e T o u c h m o n i t o r...
Страница 55: ...4 60 E l o E n t u i t i v e T o u c h m o n i t o r...
Страница 75: ...A 80 I n t e l l i T o u c h S e c u r e T o u c h G u i d e...
Страница 78: ...B 83 2210 Serial Controller Figure B 2 E271 2210 Serial Controller...
Страница 83: ...B 88 I n t e l l i T o u c h S e c u r e T o u c h G u i d e...
Страница 92: ...C 97...
Страница 93: ...C 98 I n t e l l i T o u c h S e c u r e T o u c h G u i d e...
