Figure 11 shows characteristic for sensing degree of an angle from -60o to 60o at the
front side. Detection angle by following the standing and moving action of the student in
the testing environment as shown in Figure 8 was measured. The distance is fixed at 7.0
meters. The output voltage DOUT served as the LED supplied power. Note that the
proposed sensing module can be detected between an angle of -55o to 55o at the front side
of standing and moving action of the human body. From this distance and angle, the
detection ratio was 100%.