Proposal of LED-based Peeping Prevention System

Various crimes can be committed by using camera-embedded mobile device. In particular, peeping and digital shoplifting are increasing rapidly. No direct countermeasures have been taken against these crimes, so potential victims have to prevent these crimes themselves. To overcome these problems, this paper proposes a crime prevention method called Peeping Prevention System (PPS) that uses an LED visible light beacon to prevent a camera from taking photos. PPS generates several beacons by changing the brightness intensity of an LED light bulb. After the camera receives this beacon, the proposed system forces the camera function to stop automatically. In this paper, we construct a prototype of PPS to demonstrate the system. Since the transmitter is to transmit light in public places, this transmitter must not transmit a beacon that discomforts people's eyes. The receiver is used in a smartphone camera and has programs to control the camera and receive the beacon. We confirm regular LED lighting can stop the camera function. Then, we check the reception accuracy of the camera and test the discomfort caused by the beacon. The camera is stopped within 25 seconds regardless of distance and angle between the LED lighting and the camera. Finally, a logarithmic wave is found to be a more comfortable beacon than a linear wave.