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428results about How to "Fast measurement speed" patented technology

Fabry-Perot interference absolute distance measurement method based on femtosecond optical frequency comb and device thereof

The invention relates to a Fabry-Perot interference absolute distance measurement method based on a femtosecond optical frequency comb and a device thereof. Two tunable lasers with frequency capable of being tuned within a large range and free of mode skip are simultaneously adopted, the optical wavelengths of the two lasers are respectively locked on two transmission peaks at a distance of N free spectral ranges of a to-be-detected Fabry-Perot cavity with the cavity length located in a vacuum vibration isolation cavity by utilizing the Pound-Drever-Hall (PDH) method, a wavemeter and an optical frequency comb system are used to respectively measure absolute frequency of two beams of laser, and then the free spectral ranges of the to-be-detected Fabry-Perot cavity are obtained. The cavity length of the to-be-detected Fabry-Perot cavity is obtained by means of the relationship between the to-be-detected cavity length and the free spectral ranges, frequency of the two tunable lasers can be tuned within a large range and free of mode skip, and measurement range is increased. Meanwhile, frequency of the two lasers is locked, and measurement speed can be increased. The optical frequencycomb system for measuring the frequency of the two lasers enables recurrence frequency and off-set frequency to be traced to the source of microwave frequency standard so that measurement results canhave traceability.
Owner:TSINGHUA UNIV

Photoetching machine projection objective wave aberration on-line detector and method

ActiveCN101840164AMake up timeMake up for the lack of low contrast of interference fringesPhotomechanical exposure apparatusMicrolithography exposure apparatusWave aberrationMeasurement precision
The invention discloses a photoetching machine projection objective wave aberration on-line detector and a method. A diffuser is integrated on an object space mask plate which is arranged on the object plane of a projection objective, fixed, supported and driven by an object space work piece table in the photoetching machine; an image space mask plate is arranged on the image plane of the projection objective, supported and driven by an image plane work piece table. A collimator objective is arranged after the image surface of the projection objective; and the focal plane of the object space of the collimator objective is coincided with the image plane of the projection objective. Shearing mechanism is arranged between the projection objective and a photoelectric detector. The invention can realize the continuous tunableness of the shear ratio and increases the measuring sensitivity and measuring accuracy; secondly, a square hole is used for expanding the light source, thus increasing the utilization factor of the light intensity of the exposure light source, the measuring speed and measuring accuracy; and finally, the system error self-calibration technology can rapidly obtain the wave aberration of the projection objective with high precision.
Owner:BEIJING INSTITUTE OF TECHNOLOGYGY

OCT (Optical Coherence Tomography) system for measuring optical path value of axis oculi and method

ActiveCN103976707AMeet the needs of different parts of the measurementAccurate measurementEye diagnosticsOptical axisControl system
The invention discloses an OCT (Optical Coherence Tomography) system for measuring the optical path value of an axis oculi and a method. The system comprises an OCT system light source, an optical fiber coupler, a detection system, a control system, a sample arm component, a reference arm component, a cornea before-and-back position alignment component and an outer eye camera component, wherein the outer eye camera component is used for monitoring an iris of eyes under test, and an operator controls the sample arm component to adjust a corneal vertex to the main optical axis of the OCT system according to the iris; the control system is used for judging the distance from the corneal vertex to an eye objective lens, and the distance from the corneal vertex to the eye objective lens is adjusted to meet the requirement on work of the system by means of the before-and-back adjustment of the sample arm component controlled by the control system; an optical path adjusting component adjusts the optical path of the sample arm component, and thus fundi of different human eyes are matched with the optical path of a reflector of a reference arm of the system to realize the OCT imaging of the fundi; the optical path value LEye of the axis oculi of the human eye can be measured according to the formula: LEye=LRDK1toEc+S+hRetinal. According to the OCT system for measuring the optical path value of the axis oculi and the method, the corneal vertex is accurately positioned, and by combining with the fundus OCT imaging technology, the test result of the optical path value of the axis oculi of the human eye is more accurate.
Owner:SHENZHEN CERTAINN TECH CO LTD +1

Device and method for determining border of target region of medical images

The invention discloses a device for determining a border of a target region of a medical image, which is used for differentiating the border of the target region according to corresponding physical quantitative properties reflected by tissue distribution in the medical image. The device comprises: an interactive unit, by which an operator can select the target region on the medical image; a threshold setting unit, which determines threshold values of the physical quantitative properties in the target region selected; and a thresholding segmentation unit, which divides the region to be analyzed or the region of interest into sub-regions, or fills image cells (pixels) in the region to be analyzed, wherein the region to be analyzed contains the target region, and the sub-regions are the sub-regions which are segmented in the image. The thresholding segmentation unit compares average parameter values of the physical quantitative properties of each sub-region with the threshold values and marks all the cells according to comparison results. The present invention provides a calculating and processing method and a device with clear physical significance and a simple and effective algorithm, and the method and the device are particularly suitable for processing special situations of various hearts with pathological changes in clinical art.
Owner:HONGEN HANGZHOU CHINA MEDICAL TECH +1

Apparatus for measuring parallelism of laser rangefinder sighting and receiving axes based on liquid crystal modulation

InactiveCN101231343AParallelism Quick TestElectromechanical scanning method is fast and accurateUsing optical meansOptical apparatus testingLaser transmitterLaser ranging
The invention relates to a device for measuring parallelism of sight axis and reception axis of a laser range finder based on liquid crystal modulation, which belongs to the technical field of optical precision measurement. The device comprises an off-axis parabolic mirror, a liquid crystal spatial light modulator, an integrating sphere, a visible light source, an optical fiber A, a laser delay module, an optical fiber B and a coupler, wherein the liquid crystal spatial light modulator is disposed on the focal plane of the off-axis parabolic mirror; the liquid crystal spatial light modulator, the integrating sphere, the optical fiber A, the laser delay module, the optical fiber B and the coupler are sequentially disposed behind the focal plane, and the coupler is connected with a laser emitter; and the visible light source is connected with the integrating sphere. The detection device uses the liquid crystal to perform electro-optical modulation to generate surface target for optoelectronic scanning. The invention can be used for rapid detection of the parallelism of sight axis and reception axis of the laser range finder in both indoor and outdoor environments; and has the advantages of high measurement success ratio, high precision and portability.
Owner:BEIJING INSTITUTE OF TECHNOLOGYGY

Optical measuring method and device for spatial distribution of liquid droplets of fuel nozzle

InactiveCN103760142AHigh measurement accuracySolve the problem of laser energy attenuationMachine part testingFluorescence/phosphorescenceKeroseneFluorescence
The invention discloses an optical measuring method and device for the spatial distribution of liquid droplets of a fuel nozzle. By using a characteristic that aromatic compounds in aviation kerosene can emit red-shift fluorescence signals under the excitation of ultraviolet light with a wavelength of 266 nm, a correction scheme for solving the problem that the measurement errors of spatial distribution of fuel are caused due to the attenuation of laser energy in a droplet cone is designed. The method and device disclosed by the invention are characterized in that the spatial distribution of the liquid droplets in the fuel droplet cone can be quickly and accurately measured, and have an advantage of flow field noninterference, transient and time average results can be obtained, and a deficiency that only an average result can be obtained by a fuel accumulation method is solved. The optical measuring method for the spatial distribution of liquid droplets of a fuel nozzle disclosed by the invention can be used for measuring the spatial distribution characteristics of the liquid droplets in the droplet cone of the fuel nozzle of an aero-engine or an internal combustion engine, and for fuel which does not contain fluorescent components, a tracer agent is required to be added.
Owner:INST OF ENGINEERING THERMOPHYSICS - CHINESE ACAD OF SCI

Device and method used for on-line optical measurement of two-dimensional large size of roof battenwall material

InactiveCN102798346ASolve the problem of reduced measurement accuracyHigh measurement accuracyUsing optical meansCamera lensInformation processing
The invention discloses a device and method used for on-line optical measurement of two-dimensional large size of roof battenwall materials, and belongs to the field of optical measurement on large-size geometric quantities. The measuring device comprises an optical sensing system, a data acquisition circuit system, a computer information processing system, a record display system, a warning system and a sorting control system, wherein the optical sensing system is composed of a high-resolution surface-array CCD (charge coupled device) camera, a low-distortion small-viewing-field standard lens matched with the camera, a quadrangular pyramid secondary reflection plane mirror, a high-transmittivity glass cover and four primary reflection plane mirrors, and is used for detecting the image information of four corners of a measured piece; and after calibration, the measuring device processes and computes the image information, so that the actual sizes of the measured piece are obtained and displayed. With the adoption of he device and the method provided by the invention, the problems of calibration and synchronous acquisition by a plurality of cameras are solved; and the device has high measurement speed and large-size measurement precision, and is widely applied for measuring sizes of ceramic piles, floor boards, marble tiles and the like.
Owner:TIANJIN UNIV

Differential capacitance displacement conversion and subdivision method and capacitive linear displacement measuring system

The invention relates to a differential capacitance displacement conversion and subdivision method and a capacitive linear displacement measuring system. First, the displacement is solved with the use of a conversion reference of differential capacitance displacement, no modulation, demodulation, amplifier or A / D is needed, and measurement and subdivision are simple and accurate; second, differential capacitance variation is converted into pulse width, a circuit needs no zeroing, no noise, parasitic or zero drift interference exists, and the range is not limited and is only related with the series resistance; third, the capacitive linear displacement measuring system is provided by the use of the method and the circuit, the system is large in range and can be used for performing absolute position measurement, a sensor and a circuit of the system are simple, and the system is fully digital, high in precision and good in stability, can be used in harsh environments with water, oil or dust pollution and is better than an optical grating, a ball grid or the like; and fourth, the sensor, the circuit, a display and the like are integrated into a micro (MEMS) device, the precision is at the nanometer level, motion parameters of the MEMS such as mechanical position, displacement, velocity, amplitude and frequency can be accurately measured, and parameter transformation is remotely controlled.
Owner:王祖斌
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