Sharp PN-L802B (serv.man3) Handy Guide ▷ View online
PNL-802B
Principle of Touch Panel
11
1.
The CPU on the camera control PWB
instructs the camera units to emit IR LED
light at 90 degrees in shape. The LED on
the left camera emits light to the right side
and bottom, while the LED on the right
camera emits light on the left side and
bottom.
2.
When the LED light reaches the reflectors
at the right, left and bottom, it is reflected
at the same angle of incident. The line
sensor in the camera unit detects
reflected light in the range of 90 degrees.
When the screen is touched with a stylus
or finger, etc, the touched area is shielded
and no light is reflected from the area.
PNL-802B
Principle of Touch Panel
12
PNL-802B
Principle of Touch Panel
13
3.
The CPU on the camera control PWB
calculates the touch position by the
triangulation with the detected results of
the camera units L/R, and sends
information to the connected PC via USB.
PNL-802B
Principle of Touch Panel
14
4.
When a touch pen is used, the ultrasonic
signal emitted when operating the switch
of the touch pen is received by the
microphone provided at the upper section
of the screen, and amplified by the
ultrasonic receiver PWB, judging the
switch operation.
Information of the switch operation is
sent to the camera control PWB, which
sends together with information of the
position to the external PC.
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