Murata Manufacturing Co Ltd developed a motion sensor that enables to operate a device just by moving a finger without touching it and exhibited it at CEATEC Japan 2011.
With the sensor, it becomes possible to operate a smartphone, tablet computer, etc even when the user's hand is gloved or wet. Because the sensor detects the height (z-axis) of the hand, too, it can also be used for games, Murata said.
The new sensor was made by packaging (1) three infrared-emitting elements used to realize the function of proximity sensor and (2) one light-receiving element used to realize the functions of proximity and illuminance sensors. The dimensions of the sensor are 5.0 x 4.5 x 1.2mm.
The coordinates of an object are detected based on the time difference between the time when the infrared light emitted from the three light-emitting elements is reflected on a hand, etc and the time when the light-receiving element detects the reflected light. The sensor can detect a height of up to about 20cm.
The sensor can also be used as a normal proximity or illuminance sensor.
"In the case of smartphones, it is possible to turn off the display when the user is talking on the phone," Murata said. "For smartphones, all that is needed is to replace existing proximity and illuminance sensors."