In one embodiment, the present invention is directed to a contact hearing system comprising: an ear tip including a transmit coil, wherein the transmit coil is connected to an audio processor, including an H Bridge circuit; a first input to the H Bridge circuit comprising an AND circuit wherein a first input to the AND circuit comprises a carrier signal and a second input to the AND circuit comprises an output of a delta sigma modulation circuit, wherein the delta sigma modulation circuit is a component of the audio processor; and a second input to the H Bridge circuit comprising an NAND circuit wherein a first input to the NAND circuit comprises a carrier signal and a second input to the NAND circuit comprises an output of the delta sigma modulation circuit.
- Menlo Park CA, US Douglas Webb - Los Altos CA, US Jeffrey Ward Tuttle - Santa Clara CA, US
International Classification:
H04R 25/00 H04R 3/04 H04R 25/02
Abstract:
In one embodiment, the present invention is directed to a contact hearing system comprising: an ear tip including a transmit coil, wherein the transmit coil is connected to an audio processor, including an H Bridge circuit; a first input to the H Bridge circuit comprising an AND circuit wherein a first input to the AND circuit comprises a carrier signal and a second input to the AND circuit comprises an output of a delta sigma modulation circuit, wherein the delta sigma modulation circuit is a component of the audio processor; and a second input to the H Bridge circuit comprising an NAND circuit wherein a first input to the NAND circuit comprises a carrier signal and a second input to the NAND circuit comprises an output of the delta sigma modulation circuit.
Simple Low Cost Tip-Tilt Wavefront Sensor Having Extended Dynamic Range
Malcolm J. Northcott - Felton CA, US J. Elon Graves - Los Gatos CA, US Siegfried Fleischer - Campbell CA, US Paolo Zambon - Campbell CA, US Jeffrey Tuttle - Campbell CA, US Rebecca Chang - Campbell CA, US
International Classification:
H04B 10/2507
US Classification:
398 25
Abstract:
A low cost, high reliability system for correcting aberrations in optical signals is disclosed. A foreoptic assembly, such as a telescope, receives an incoming optical signal and directs it to an active optical element, such as a fast steering mirror. The incoming optical signal is diffracted by a diffractive optical element to shape the image that is formed at a wavefront sensor, such as a quad-cell. The wavefront sensor measures a tip-tilt aberration of the incoming optical signal and the active optical element is adjusted to correct the measured aberration. An outgoing optical signal can be transmitted along substantially the same optical path as the incoming optical signal, but in the opposite direction. Thus, the aberration measured from the incoming optical signal can be automatically accounted for in the outgoing optical signal.