One of the core technologies of the sensor that has not been disclosed until now is the characteristics of the phototransistor.

The output of the AD converter is compared as a curve when the hand is moved closer or farther away under the same conditions. The LTR-209 sensor used has good sensitivity when the object is far away. On the other hand, when the object is close, the sensitivity is poor and once it is saturated, the distance cannot be detected. What is important is the performance at long distances, and this characteristic directly determines the sensor's performance. It is thanks to this phototransistor that it can detect a distance of 8 inches.