Piezoelectric transducer for data entry device

Abstract

A piezoelectric transducer is provided, in which a piezoelectric shell has conductive layers on the outside and inside of the shell, which are adapted to be connected to a signal input source. When the conductive layers are activated, the piezoelectric layer resonates to produce an output signal waveform from the shell structure. An alternative embodiment includes a flat piezoelectric layer with opposing conductive layers, which is then formed into a shell structure. In preferred embodiments, an inner spool is located within the shell structure, which acts to increase the output sound pressure level for the transducer. To increase the sound pressure level further, the inner spool preferably includes a recessed area, which defines a void between the inner conductive layer on the shell and the recessed area. The void acts to increase the characteristic output sound pressure level for the transducer. In some embodiments, the piezoelectric transducer is placed into a data entry device, such as a transmitter pen, and is used to transmit a signal from the pen to one or more receivers, which can be used to accurately determine the location of the pen, in relation to an electronic tablet or white board. The transmitter pen preferably includes a writing pen, wherein the writing tip extends through the shell structure of the piezoelectric transducer.