Electronic control button operated by sound absorption

Abstract

An electronic control or touch button, with no moving button parts and operated by sound absorption, including in a first embodiment (FIG. 1) a cylindrical, metal, outer casing (1) of comparable diameter to standard buttons. The casing holds a glass, ball-shaped button (2) serving as a sound transmitting medium, the exposed side of which serves as the button touch surface (3). Behind the ball-shaped button is a printed circuit board (4), carrying on it an integrated circuit (IC; 5), an ultrasound transducer (6), and a series of light emitting diodes (LED; 7). In operation the transducer routinely sends sound (or ultrasound) waves into the glass ball and then receives back the echoes of its transmission--in sonar fashion. If skin or other material comes into contact with the touch surface, some of the sound will be absorbed by the material, and the reduced echoes detected by the IC, which is analyzing the echoes. When the echoes are so reduced (compare upper and lower wave form traces in FIG. 4B), the IC then causes the electrical or electronic function controlled by the touch button to be activated (or deactivated, depending on the design, or otherwise altered). The LEDs then are activated, providing visual feedback to the button pusher. Additionally, tactile and/or audio feedback may be implemented. An exemplary circuit is illustrated in FIG. 3. A second embodiment (FIGS. 2 & 2A) uses a solid metal plate (11) having two button-like-configured depressions (13A & B) surrounded by two, concentric isolation rings (14A/14A & 14B/14B).