Patent ID: 6906807

Claim:
An optical transducer, comprising: a housing including a light source and a light detector laterally spaced from the light source; and a deformable membrane mounted to said housing over said light source and light detector such that an inner surface of the membrane reflects, to said light detector light emanating from the light source, and the light detector produces an output electrical signal modulated in accordance with the deformations of the deformable membrane; said deformable membrane being mounted to said housing by a frame which fixes the outer peripheral edge of the membrane over an opening in the housing; said inner surface of the deformable membrane having a small central region of high light reflectivity to maximize said output electrical signal produced by the deformations of the membrane, and a large outer region of lower light reflectivity to facilitate mounting the membrane and to minimize noise in said output electrical signal produced by multi-reflection of light from said light source to said light detector said optical transducer further comprising a spacer between said housing and said frame; said spacer defining a predetermined space between said deformable membrane and said light source and light detector for producing relatively large, linear, chances in said output electrical signal in response to the deformations of the membrane.