Phone-or Ltd.

Qualitrol Corporation

Qualitrol Company LLC

Vibrosound Ltd.

Optoacoustics Ltd.

Alexander Kots

Alexander Paritsky

Yuvi Kahana

Okihiro Kobayashi

Kazuo Takahashi

Nobuhiro Miyahara

A reflective element for directing an optical signal into a fiber optic sensor having an optical fiber includes a plane containing a sharply defined straight line that separates between a first area of low reflectivity and a second area of high reflectivity. The plane is disposed parallel to a free end surface of the optical fiber so that the free end surface intersects the line of the reflective element, whereby relative movement between the free end surface of the optical fiber and the line in response to a physical change sensed by the fiber optic sensor induces variations in an optical signal reflected by the reflective element through the optical fiber, which variations allow measurement of the physical change.

Reflective element for fiber optic sensor

A fiber optic accelerometer has a hollow body that supports an optical fiber therein so as to form a cantilever section, a fiber optic splitter coupled to a first end of the optical fiber and a light source for directing light into the optical fiber via a first branch of the optical splitter. A photo detector receives light conveyed through the optical fiber via a second branch of the optical splitter and measures an intensity of the received light. A reflective target supported at a second end of the hollow body is axially aligned with the second end of the optical fiber in the absence of force. Upon acceleration the cantilever section moves such that its position relative to the reflective target changes thereby reducing the instantaneous intensity of light reflected by the target into the second end of the optical fiber and measured by the photo detector.

Fiber optic accelerometer

An arrangement for a fiber optic microphone having at least one pair of optical fibers, each having an input end portion and an output end portion made of a material having a critical refractive angle &#x3b8;and having a numerical aperture NA. The input end portion of a first fiber is connectable to a source of light and the output end portion of a second fiber is connectable to a photoelectrical transducer. Both end portions have an inner diameter, an axis and a rim. The input and output end portions are mutually affixed along a single plane with their rims touching each other at a point, the axes forming an angle &#x3b1; therebetween. The rims are cut with respect to the axis, at an angle in a plane perpendicular to the single plane and to a bisector of angle &#x3b1; at the point, where &#x3b1;=&#xd7;&#x3b8;&#x2212;NA.

Fiber optic microphone and a communication system utilizing same

An optical transducer includes a light source and a light detector mounted on a base member in laterally spaced relation to each other, a deformable membrane overlying the light source and light detector, and a light transparent body between the light source and light detector on one side, and the deformable membrane on the opposite side, such as to direct light emanating from the light source to the membrane, and to direct light reflected from the membrane to the light detector in accordance with the deformations of the membrane. According to the described method of making the optical transducer, the light source and light detector are enclosed in a first casing closed at one end by the base member and open at the opposite end; and the light transparent body is enclosed in a second casing to be closed at one end by the deformable membrane and open at the opposite end. The two casings are attached to each other with their open ends facing each other such that the light transparent body of the second casing overlies the light source and light detector of the first casing.

Optical transducers and method of making same

An optical transducer includes a housing containing a light source and a light detector laterally spaced from the light source; and a deformable membrane mounted over the light source and light detector such that an inner surface of the membrane reflects light from the light source to the light detector to produce, from the light detector, an output electrical signal modulated in accordance with the deformations of the membrane. The inner surface of the membrane has a small central region of high light reflectivity to maximize the output electrical signal produced by the deformations of the membrane, and a large outer region of lower light reflectivity to minimize noise in the output electrical signal produced by multi-reflection of light from the light source to the light detector. The membrane is preferably formed in its outer region with circular corrugations coaxial with each other and with the central region of high light reflectivity to increase the deformability of the central region.

Membrane type optical transducers particularly useful as optical microphones

A lightwaveguide panel to be used with a a mobile telephone (MT) or personal digital assistant (PDA), the pannel comprises a first portion for lighting an LCD and/or a keyboard, and a second integral portion, said second portion including a first inclined surface for directing light from a source of light onto a light-reflecting acoustically responsive membrane, and a second inclined surface for directing light from said membrane onto a photo-detector.

Optical microphone for communication and other devices

An optical transducer includes a base member, a light source carried on a face of the base member, a light detector carried on the face of the base member, a displaceable member overlying and spaced from the light source and light detector and effective to reflect light from the light source to the light detector, and light shielding means effective to shield the light detector from exposure to the light source except for the light reflected by the displaceable member from the light source to the light detector. The light detector is configured to substantially surround the light source such as to receive light emitted in substantially all directions from the light source for reflection to the light detector by the displaceable member.

Optical transducers of high sensitivity

A method of making optical transducers by producing an integrated structure including, in a rectangular matrix array, a plurality of discrete light sources, a plurality of discrete light detectors each laterally spaced from a light source, a light shield in the space between a light source and a light detector for shielding the light detector from direct exposure to the light source, and a transparent plastic potting material embedding the light sources, light detectors and light shield; and cutting the integrated structure, along lines of the matrix, into individual optical units, each including a light source, a light detector, a light shield therebetween all embedded in the transparent plastic potting material, and an optical window for outputting light from the light source and for transmitting to the light detector light reflected back from the light source. Also described are optical units of a structure facilitating mass production of such optical transducers and providing a sturdy construction permitting rough handling.

Optical transducers and methods of making same

An optical transducer includes a base member, a light source carried on a face of the base member, a light detector carried on the face of the base member laterally spaced from the light source, an optical shield extending from the face of the base member between the light source and light detector, and a displaceable member overlying, and spaced from, the light source, light detector and optical shield, and effective to reflect light from the light source to the light detector. The optical shield includes a transparent plate extending from the face of the base member between the light source and light detector, and carrying a thin layer of a light-blocking material to shield the light detector from direct exposure to the light source. The light source, light detector, and optical shield are all embedded in a transparent plastic potting material. Also described is a method of making such optical transducers by producing an intermediate matrix of a plurality of such light sources, light detectors and optical shields and cutting the matrix into individual optical units.

The invention provides a head for an optical microphone/sensor, including first and second light guides; the first light guide being coupled at an input end to a source of light and having an output end portion for transmitting light onto a membrane; the second light guide having an input end portion for receiving light reflected from the membrane and an output end coupled to a photodetector; the output end and input end portions each having an upper face and side surfaces and being disposed in close proximity to each other and optically separated along adjacent surfaces; characterized in that in order to utilize maximum light energy transmitted through the light guides by the light source, reflected by the membrane and received by the photodetector, at least one of the faces or surfaces is configured to extend along one or more planes which differ from the plane including the axes of the transmission of the light energy emitted from the light source and received by the photodetector.

Optical microphone/sensors

The invention provides a microphone/sensor, including a housing defining a chamber and having an opening; at least one pair of optical waveguides, each having an input end portion and an output end portion, the input end portion of a first waveguide being optically coupled to a source of light and the output end portion of a second waveguide being optically coupled to a light intensity detector; a membrane having two opposite surfaces extending across the opening to form a sealed-off chamber inside the housing; a head, including the input end portion of the second optical waveguide and the output end portion of the first optical waveguide, affixedly located at least in proximity to each other, each of the output end portion of the first waveguide and input end portion of the second waveguide having an optical axis and an output face, the output face being cut at an angle &thgr; with respect to the axis, the axes forming an angle &agr; between them, wherein, upon operation, the light emerging from the output end portion of the first waveguide impinges on a surface of the membrane at an angle of incidence &bgr;, and wherein &bgr;&equals;&fnof;(&agr;,&thgr;); the microphone/sensor further including pressure-equalizing means for equalizing the pressure on the two surfaces of the membrane.

Optical microphone/sensor

A communication helmet having an enhanced noise reduction effect. The communication helmet incorporates a microphone disposed in the vicinity of the mouth of the speaker wearing the helmet. The microphone is an optical microphone comprising a diaphragm ( ) vibrating with sound pressure, a case ( ) containing the diaphragm ( ) and having a first opening ( ) and a second opening ( ) open in symmetric positions and facing the diaphragm ( ), a light source ( ) for projecting a light beam to the diaphragm ( ), and a photodetector ( ) receiving part of the reflected light of the light beam projected to the diaphragm ( ) and outputting a signal corresponding to the vibration of the diaphragm ( ). The optical microphone is fixed to a fixing base ( ) at a predetermined angle so that the incoming sound wave may uniformly enter the first opening ( ) and the second opening ( ). The fixing base ( ) is attached to the helmet with a space so that the external sound wave may uniformly enter the first opening ( ) and the second opening ( ).

Communication helmet

Small optical microphone/sensor

A device for collecting sounds from objects comprises a plurality of microphones whose directivity can be varied depending on the environment in which each object is located. An optical microphone includes a vibration board ( ) which vibrates by sound pressure, a light source ( ) for emitting a light beam to the vibration board ( ), a photodetector ( ) which receives the light beam reflected from the vibration board ( ) and produces a signal corresponding to the vibration of the vibration board ( ), a drive circuit ( ) for supplying the light source ( ) with predetermined current, and a negative feedback circuit ( ) that supplies the drive circuit ( ) with a negative feedback signal consisting of a signal output from the photodetector ( ). The negative feedback circuit ( ) changes the amount of negative feedback depending on the environment.

Growing community of inventors

Ashdod, Israel

Alexander Kots