8860results about "Converting sensor output optically" patented technology

Positional information of a movable body in a Y-axis direction is measured using an interferometer and an encoder whose short-term stability of measurement values excels when compared with the interferometer, and based on the measurement results, a predetermined calibration operation for obtaining correction information for correcting measurement values of the encoder is performed. Accordingly, by using measurement values of the interferometer, correction information for correcting the measurement values of the encoder whose short-term stability of the measurement values excels the interferometer is obtained. Then, based on the measurement values of the encoder and the correction information, the movable body is driven in the Y-axis direction with good precision.

The central system component of the present invention is a flexible “smart cable” which enables accurate measurement of local curvature and torsion along its length. These quantities are then used to infer the position and attitude of one end of the cable relative to the other. Sufficiently accurate measurements of the local curvature and torsion along the cable allow reconstruction of the entire cable shape, including the relative position and orientation of the end points. The smart cable for making these measurements comprises a multicore optical fiber, with individual fiber cores constructed to operate in the single mode regime, but positioned close enough to cause cross-talk (mode coupling) between cores over the length of the fiber. This cross-talk is very sensitive to the distribution of strains (curvature and torsion) along the cable.

An optical reader is suitable for reading 2-dimensional indicia. The optical reading device, that may include a bar code reader, comprises a guide whose length along the optical reader optical axis is such that when that guide contacts the part or equipment surrounding the indicia to be read, that indicia is within the optical reader depth of field. The reader comprises a housing having therein a source of illumination and optics for producing a diverging beam for illuminating indica. A spacing element transparent guide is removably attached to the housing, and does not block indicia. The line of contact of the guide with the data carrier is substantially fully visible to the operator, who can thus confirm that the guide is in proper operating position relative to the indica prior to initiating a reading operation. A reading operation can be initiated by pressing on the guide to actuate a switch, or on a manual trigger.

A motor may be configured to drive a drive shaft and an engagement member supported on the drive shaft. A detectable feature comprising a rotary member may be supported on the drive shaft such that movement of the drive shaft by the motor changes a state of the detectable feature. At least one sensor may be arranged to detect the state of the detectable feature. Circuitry may be configured to provide a signal in response to a change in the state of the detectable feature detected by the at least one sensor.

The X, Y and Rx positions of a mask stage are measured using two optical encoder-reading heads measuring displacements of respective grid gratings mounted on the mask stage. The grid gratings are preferably provided on cut-away portions of the mask table so as to be co-planar with the pattern on the mask itself. Measurements of the table position in the other degrees of freedom can be measured with capacitative or optical height sensors.

A position-measuring device is for measuring the position of two objects that are movable relative to one another. The device includes a measuring graduation, which is connected to one of the two objects, as well as at least one scanning system for scanning the measuring graduation, which is connected to the other of the two objects. The scanning system is arranged to permit a simultaneous determination of the position values along at least one lateral and along one vertical shift direction of the objects.

A novel system and method for achieving accurate readings of the rotational speed, number of revolutions and direction of rotation of a utility system. More specifically, a system and method for retrofitting existing utility meters with a lightweight tape, having contrasting sections of reflective and non-reflective material applied thereto, which is read by optical sensors as the lightweight tape passes by with the revolutions of the disk of the utility meter. Additionally, the system and method detects unauthorized use of the utility or tampering with the utility meter and its functions.

The present invention provides a displacement detection apparatus uses short scales and can provide a long measurable range comparable to a single long scale with a short bed length. The displacement detection apparatus includes a scale, a first head and a second head adapted to detect periodic analog signals of a plurality of different types, a first processing section and a second processing section that detects the first differential value and the second differential value between the immediately preceding positional data and the current positional data obtained by sampling the periodic analog signals of a plurality of different types, a switching section that selectively switches from the first differential value to the second differential value or vice versa, a scale position detection section that detects the scale getting to a predetermined position relative to the first head or a predetermined position relative to the second head, a switching control section that causes the switching section to switch from either of the differential values to the other in response to the detection of the scale getting to the predetermined position, and an addition section that adds the first differential value or the second differential value selectively switched by the switching control section and outputting it as positional information.

An agile optical sensor based on scanning optical interferometry is proposed. The preferred embodiment uses a retroreflective sensing design while another embodiment uses a transmissive sensing design. The basic invention uses wavelength tuning to enable an optical scanning beam and a wavelength dispersive element like a grating to act as a beam splitter and beam combiner to create the two beams required for interferometry. A compact and environmentally robust version of the sensor is an all-fiber in-line low noise delivery design using a fiber circulator, optical fiber, and fiber lens connected to a Grating-optic and reflective sensor chip.

For detecting three-dimensional shapes of an elongated flexible body, a sensor cable to be placed in a passage or channel which is formed axially and coextensively within the elongated flexible body. The sensor cable has two pairs of fiber Bragg grating strands within a tubular carrier casing. A signal light beam containing Bragg wavelength bands is projected from a light source to input same to refractive index change portions in the fiber Bragg grating strands. Reflection diffraction light signals from the refractive index change portions are received by a signal processor to measure the degree of strain at each one of the respective refractive index change portions by comparing wavelengths of the reflection diffraction light signals with reference wavelength.

The invention relates to a method for treating subterranean formation comprising providing distributed temperature sensors, injecting a treatment fluid and monitoring the temperature across the treatment interval during the injection process.

A speckle readhead includes a light source that outputs light towards an optically rough surface. Light scattered from this surface contains speckles. The scattered light is imaged onto an image detector, captured and stored. Subsequently, a second image is captured and stored. The two images are repeatedly compared at different offsets in a displacement direction. The comparison having the highest value indicates the amount of displacement between the readhead and the surface that occurred between taking the two images. An optical system of the readhead includes a lens and an aperture. The aperture can be round, with a diameter chosen so that the average size of the speckles is approximately equal to, or larger than, the dimensions of the elements of the image detector. The dimension of the aperture in a direction perpendicular to the direction of displacement can be reduced. Thus, the imaged speckles in that direction will be greater than the dimension of the image detector elements in that direction. Such a readhead is relatively insensitive to lateral offsets. The lens can be a cylindrical lens that magnifies the relative motion along the direction of displacement but does not magnify relative motions in the direction perpendicular to the direction of displacement. The optical system can also be telecentric. Thus, the readhead is relatively insensitive to both separation and relative motions between the readhead and the surface. The light source can be modulated to prevent smearing the speckles across the image detector. The light source can be strobed to freeze the image.

For detecting three-dimensional shapes of an elongated flexible body, a sensor cable to be placed in a passage or channel which is formed axially and coextensively within the elongated flexible body. The sensor cable has two pairs of fiber Bragg grating strands within a tubular carrier casing. A signal light beam containing Bragg wavelength bands is projected from a light source to input same to refractive index change portions in the fiber Bragg grating strands. Reflection diffraction light signals from the refractive index change portions are received by a signal processor to measure the degree of strain at each one of the respective refractive index change portions by comparing wavelengths of the reflection diffraction light signals with reference wavelength.

A cockpit display system has a display, such as a multi-function display (MFD) for displaying a graphical representation of an input device when a sensor senses that an aviator's finger is proximate to the input device. The display graphically depicts in real-time the position of the aviator's finger relative to the buttons of the input device. The aviator's finger can be depicted by an icon, shading or highlighting. When the aviator lightly touches a button, the graphical representation of that button can for example be highlighted, shaded or colored. Furthermore, when the button is firmly depressed, the graphical representation of that button can change color or shading. The aviator can thus operate any awkwardly located input device by simply reaching toward the input device and then guiding his finger to the correct button by looking at the graphical representation of the input device.

A system such as for sensing strain or temperature of an aircraft and for transmitting information in communication systems. A sensor array includes a first light responsive Bragg grating sensor having a first operating bandwidth and a second light responsive Bragg grating sensor having a second operating bandwidth. Each sensor modifies light provided to it at a wavelength indicative of changes in strain or temperature. The second sensor operates within a bandwidth which is different from the operating bandwidth of the first sensor. A tunable light source such as an LED and tunable etalon provides light for illuminating the first and second sensors, the provided light having a wavelength which varies within a band including the first and second bandwidths. A detecting circuit provides signals representative of light modified by the first and second sensors. A processor processes the representative signals to determine the strain and / or temperature.

The present invention provides a method for detecting vibration information by receiving electromagnetic radiation reflected or emitted from a biological organism at a light amplitude modulation detector array to provide real-time imaging of the target object. The detected radiation may be visible light, infrared or ultraviolet radiation, and / or of other desired frequency ranges. The detected radiation is preferably AC-coupled to isolate components relating to oscillations of the biological organism from components relating to ambient radiation, e.g. background sunlight. The isolated oscillations may then be digitized, stored, and subjected to processing such as a Fourier transform to generate outputs representative of frequencies of oscillation. This output can then be used for analysis of the target object.

Remote sensing in an environment having temperatures greater than 300° C., using an optical fiber having a core (10), a cladding (20), and a metallic protective coating (30) on the cladding to protect a surface of the cladding, the cladding having a diameter greater than 150 μm, and a thickness of at least 50 μm. The larger diameter cladding means stress from the metallic protective layer can be reduced, giving lower optical loss and better hydrogen protection. A metal conduit (330) encapsulates the sensing fiber, and a pump evacuates the conduit to reduce hydrogen seepage. Ceramic splice protectors are used. OTDR is used to determine differential loss at different locations along the fiber. A reflective element at the far-end of the fiber eases calibration.

An optical sensor for a delivery device having a piston that displaces a substance, such as a fluid, from a reservoir. The optical sensor has a light source and a detector array for imaging encoding features disposed along a plunger rod coupled to the piston. By virtue of the pattern of encoding features, an absolute position of the plunger rod relative to a fiducial position may be determined uniquely. Thus, the volume of fluid remaining in the reservoir, the rate of fluid delivery, and proper loading of the reservoir may be accurately ascertained. Additionally, the encoding may serve to uniquely identify a version of the reservoir which may be supplied in various versions corresponding, for example, to differing concentrations of a therapeutic agent to be dispensed.

Under a known pressure is externally applied to a reference member to which an optical fiber is fixed, test light is allowed to enter the optical fiber, and at least one of a reference Brillouin measurement for determining a reference Brillouin frequency shift amount based on the Brillouin scattering phenomenon, and a reference Rayleigh measurement for determining a reference Rayleigh frequency shift amount based on the Rayleigh scattering phenomenon is performed. A Brillouin measurement coefficient or a Rayleigh measurement coefficient is determined from these calculation results. An optical fiber is fixed to a sample member, the volumetric change of which is unknown, and the same sample Brillouin measurement or sample Rayleigh measurement is performed to determine the frequency shift amount. The volumetric change of the sample member is determined from the sample Brillouin or the sample Rayleigh frequency shift amount, and from the Brillouin or the Rayleigh measurement coefficient.

One aspect of the technology involves a system for measuring the rotational position of a rotating shaft, including a field source configured to generate a measurable field, a sensor configured to measure the generated field, and a target that is configured to modify the generated field as measured by the sensor to have a shape with (a) at least one measurable feature for a zero reference point, and (b) a shape that varies throughout one or more angles such that a rotational position of the shaft is determined with a selected angular accuracy. There is also a device that receives a query for the rotational position of the shaft a device that responds to the query. Another aspect involves generating multi-frequency vibrations with a single linear resonant actuator (LRA). This LRA can exhibit a beat pattern in response to being driven by the sum of two different sinusoidal functions.

An optical improvement for angular position sensors, which may be used to determine the spatial coordinates of a small source of light (or other energy) in a 3-dimensional volume. Such sensors normally include a linear photosensitive image detector such as a photodiode array or a charge-coupled device (CCD). An irregular pattern of parallel slits is described which increases the amount of light gathered while avoiding the undesirable characteristics of lens optics for this application. One optimal type of irregular pattern is the uniformly redundant array. A mathematical correlation function together with a polynomial interpolation function can determine the displacement of the image on the detector and thereby the location of the source relative to one angular dimension. Given the locations and orientations of several sensors in a 3-dimensional coordinate system and given the angles measured by each, the location of the point source can be computed.

The present disclosure provides systems utilizing fiber optics for monitoring downhole parameters and the operation and conditions of downhole tools and controlling injection operations based on measurements in an injection well and / or a production well.

A measuring device for providing data corresponding to a geometric configuration in space, in the form of a flexible, compliant, measurement member capable of bending in at least one degree of freedom and extending along a medial axis or plane. The member has spaced flexure sensors distributed at known locations on the member and separated by known sensor spacing intervals to provide flexure signals indicating the local state of flexure present at the locations. The member comprises a multiplicity of formed, i.e. shaped, fibers, these fibers including sensing fibers having sensing portions which provide the flexure sensors, the sensing portions of different fibers being located at differing distances along the member so as to be located at the sensor spacing intervals, the formed fibers being in mutually supporting relationship, as by continuous or repeated contact with each other. Such fibers may constitute most or all of the member.

This invention provides a method for controlling production operations using fiber optic devices. An optical fiber carrying fiber-optic sensors is deployed downhole to provide information about downhole conditions. Parameters related to the chemicals being used for surface treatments are measured in real time and on-line, and these measured parameters are used to control the dosage of chemicals into the surface treatment system. The information is also used to control downhole devices that may be a packer, choke, sliding sleeve, perforating device, flow control valve, completion device, an anchor or any other device. Provision is also made for control of secondary recovery operations online using the downhole sensors to monitor the reservoir conditions. The present invention also provides a method of generating motive power in a wellbore utilizing optical energy. This can be done directly or indirectly, e.g., by first producing electrical energy that is then converted to another form of energy.

A directionally-sensitive device for detecting and processing vibration waves includes an array of polymeric optical waveguide resonators positioned between a light source, such as an LED array, and a light detector, such as a photodiode array. The resonators which are preferably oriented substantially perpendicularly with respect to incoming vibration waves, vibrate when a wave is detected, thus modulating light signals that are transmitted between the light source and the light detector. The light detector converts the modulated light into electrical signals which, in a preferred embodiment, are used to drive either the speaker of a hearing aid or the electrode array of a cochlear implant. The device is manufactured using a combination of traditional semiconductor processes and polymer microfabrication techniques.

The invention relates to an instrumented tubular device for transporting a pressurized fluid notably in the field of oil exploration and in that of the transport of gas or hydrocarbons. This device comprises a tube (20) in which this fluid flows, with which are associated means for measuring the main deformations of this tube, and means for measuring the temperature of the fluid in the tube. This tube is equipped with measurement means integral with its surface and offset by at least one remote optical cable towards an electronic measurement system. These measurement means are means for assembling at least two non-parallel optical fibers which comprise at least three assemblies (B1, B2, B3) of at least two optical gages with Bragg gratings attached to at least three measurement locations (22) and connected to the remote optical cable (23) via optical fibers. At least one assembly further comprises a temperature gage.

A reflective optical encoder for a gear train. The reflective optical encoder includes a gear train with a plurality of gears. Each of the gears is operably coupled to at least one other gear of the plurality of gears. A reflective code pattern is accessible on a surface of at least one of the gears. A reflective optical sensor detects light reflected by the reflective code pattern. Position logic coupled to the optical sensor determines a rotational parameter of the gear train based on the light reflected by the reflective code pattern. Additionally, the position logic may determine rotational parameter of a pinion coupled to the gear train based on the rotational parameter of the gear train.

A camera acquires a 4D light field of a scene. The camera includes a lens and sensor. A mask is arranged in a straight optical path between the lens and the sensor. The mask including an attenuation pattern to spatially modulate the 4D light field acquired of the scene by the sensor. The pattern has a low spatial frequency when the mask is arranged near the lens, and a high spatial frequency when the mask is arranged near the sensor.