Patents
Literature
Hiro is an intelligent assistant for R&D personnel, combined with Patent DNA, to facilitate innovative research.
Hiro

557 results about "Modulation transfer" patented technology

Optical transfer function or modulation transfer functions are thus generally two-dimensional functions. The following figures shows the two-dimensional equivalent of the ideal and the imperfect system discussed earlier, for an optical system with trefoil, a non-rotational-symmetric aberration.

Contrast-enhancing aspheric intraocular lens

The present invention provides an intraocular lens (IOL) having an optic with a posterior and an anterior refractive surfaces, at least one of which has an aspherical profile, typically characterized by a non-zero conic constant, for controlling the aberrations of a patient's eye in which the IOL is implanted. Preferably, the IOL's asphericity, together with the aberrations of the patient's eye, cooperate to provide an image contrast characterized by a calculated modulation transfer function (MTF) of at least about 0.25 and a depth of field of at least about 0.75 Diopters.
Owner:ALCON INC +1

Methods and systems for inspecting reticles using aerial imaging at off-stepper wavelengths

Methods and systems for inspecting a reticle are provided. A method may include forming an aerial image of the reticle with an inspection system at a wavelength different from a wavelength of an exposure system. The method may also include correcting the aerial image for differences between modulation transfer functions (MTF) of the inspection system and the exposure system. In this manner, the corrected aerial image may be substantially equivalent to an image of the reticle that would be printed onto a specimen by the exposure system at the wavelength of the exposure system. In addition, the method may include detecting defects on the reticle using the corrected aerial image. The detected defects may include approximately all of the defects that would be printed onto a specimen by the exposure system using the reticle.
Owner:KLA TENCOR TECH CORP

Dual-stage high-contrast electronic image display

Electronic displays are provided which can reproduce image data with high contrast ratios and a gray scale range comparable to conventional X-ray film viewed on a light box. One such display includes a rear low-resolution LCD or DLP display which projects an image onto a high-resolution LCD display. In such embodiments, the mechanical and optical registration between the two displays is not critical. Therefore, modulation transfer function and distortion of the projection optics are not critical. Accordingly, the brightness of the inventive display can be maximized with high power lamps and high aperture projection optics. Because the display has a high dynamic range, the need for dynamic range compression algorithms is reduced.
Owner:SAMSUNG ELECTRONICS CO LTD

Large depth-of-field imaging system and iris recogniton system

(A2) An extended depth of field (DOF) imaging system (10) is disclosed that has a corresponding extended depth of focus (DOF′) by virtue of its optical system (20) having a select amount of spherical aberration. The imaging system has an image processing unit (54) adapted to process the raw images and perform contrast enhancement to form processed images. The image processing includes restoring the defocused modulation transfer functions (MTFs) using a gain function (G) and the amount of defocus. The imaging system can include an illumination system (60) that illuminates the object being imaged to establish a distance (DH) between the optical system and the object, where distance DH is used in the restoring of the MTF. An iris-recognition (I-R) system based on the enhanced DOF imaging system is also disclosed.; Optical system embodiments for use in the DOF imaging system that can provide select amounts of spherical aberration—and thus select increases in DOF—without increasing the adverse impact of other aberrations on image formation are also disclosed.
Owner:GLOBAL BIONIC OPTICS PTY LTD

Image quality mapper for progressive eyeglasses

An instrument and method for optical testing of an eyeglass lens, including progressive addition lenses, to obtain image quality measurements includes an illumination system for presenting a beam of light to a test lens, a test lens positioning system for rotating the test lens so that different areas on the lens are illuminated, a zoom lens for focusing the beam at a constant effective focal length, a detection system for recording and measuring image quality of the test lens, and an alignment boom for conveying the zoom lens and the detection system such that the optical axis remains aligned with the beam existing the test lens. The instrument is fully automated and capable of obtaining measurements of the power, astigmatism, prism and modulation transfer function at various locations on the surface of the lens.
Owner:ESSILOR INT CIE GEN DOPTIQUE

Method and apparatus for optimizing optical system and recording medium with program for optimizing optical system

Optical properties with high non-linearity such as a modulation transfer function (MTF) are efficiently optimized at high speed compared to conventional methods. An optimal solution of an optical system is obtained in a first optimization unit using a merit function on aberration. Weights or target values of the merit function on aberration is automatically adjusted in a second optimization unit in a manner that an evaluated value of the MTF or the like approaches a desired value. The first optimization unit re-optimizes the optical system using the weights or target values which have been automatically adjusted. Thus, automated is a function equivalent to the operation which has been conducted by a designer such as adjustment to weights or target values.
Owner:FUJI PHOTO OPTICAL CO LTD

Method of and system for determining the lower limit of decoding resolution in an imaging-based bar code symbol reader

A method of determining the lower limit of decoding resolution in a digital imaging-based bar code symbol reader. A software-based optical design program is used to generate the composite DOF chart of image formation optics employed in the digital imaging-based bar code symbol reader. The modulation transfer function (MTF) of the object image is used to determine the smallest mil size code that can be decoded, at a given object distance, to produce an optical performance curve. The program calculates the size of the field of view (FOV) of a single sensor pixel, when projected through the image formation optics and out into object space. For both the 1.4 and 1.6 sampling limit pixel rules, the calculated FOV values are plotted on the same axes as the optical performance curve. Using graphical solution techniques, the sampling limit line of choice determines the lower limit of the decoding resolution in the imaging-based bar code symbol reader.
Owner:METROLOGIC INSTR

Imaging systems and methods

InactiveUS20060108505A1Excellent transfer functionRadiation pyrometrySolid-state devicesAngle of incidenceOphthalmology
Imaging systems and methods are provided. One exemplary system incorporates multiple lenses that are individually configured to receive multi-wavelength light from an object to be imaged. Each lens provides an optimal modulation transfer function (MTF) for an individual wavelength contained in the multi-wavelength light when this individual wavelength of light strikes the lens at a particular incident angle. Associated with each lens is a color filter and a sensor. The color filter receives the multi-wavelength light from the lens, and transmits the individual wavelength of light on to the sensor. The image signals obtained from each of the multiple sensors are combined to generate an image of the object.
Owner:APTINA IMAGING CORP

Apparatus and method for measuring dynamic target modulation transfer function

The invention relates to a dynamic object modulation transfer function measuring method and a device thereof, pertaining to the optical property measurement field. The invention aims at providing a dynamic object modulation transfer function measuring method and a device thereof which can carry out the dynamic object modulation transfer function measurement under different fields of view, namely, uniform linear motion, uniformly-accelerated rectilinear motion, simple harmonic motion, but also can measure static target modulation transfer function and separate the static target modulation transfer function from whole machine modulation transfer function. The device consists of a light source, a collimating lens, a pupil coupling system and an electro-optical imaging system which are arranged along the ray propagation direction in sequence; the electro-optical imaging system carries out imaging towards the light source moving along the guide rail direction and line spread function is obtained from the image and carried out one-dimensional Fourier transformation so as to obtain the dynamic object modulation transfer function. The method and the device of the invention are not only suitable for static image evaluation field but also for the image evaluation field of dynamic object imaging by a time-delay electro-optical imaging system.
Owner:江苏亚星波纹管有限公司

Dynamic image modulation transfer function measuring device

The invention relates to a dynamic image modulation transfer function measuring device belonging to the field of optical property tests and sequentially comprising a point light source, a collimator objective, a pupil coupling system and a photoelectronic imaging system along the light propagating direction, and also comprising a driver, a motor, a lead screw, a computer and an image collector card, wherein the pupil coupling system adopts parallel light incidence and parallel light emergence; the entrance pupil of the pupil coupling system and the exit pupil of the collimator objective have same size and same position; the exit pupil of the pupil coupling system and the entrance pupil of the photoelectronic imaging system have same size and same position; the pupil coupling system is dismantled, and the exit pupil of the collimator objector and the entrance pupil of the photoelectronic imaging system have same size and same position; and the time difference of image acquisition of the photoelectronic imaging system and the travel of a sliding block I is set by a hardware delay circuit or software delay program. The device can not only eliminate image vignetting caused by target travel, but also can realize time comparison of the measurement result and the theoretical model.
Owner:HARBIN INST OF TECH

Compound modulation transfer function for laser surgery and other optical applications

InactiveUS20120033182A1Mitigates presbyopiaMitigates and treats vision conditionLaser surgeryEye diagnosticsModulation functionLaser surgery
Methods, devices, and systems establish an optical surface shape that mitigates or treats a vision condition in a patient. An optical surface shape for a particular patient can be determined using a set of patient parameters for the specific patient by using a compound modulation transfer function (CMTF). The compound modulation transfer function can include a combination of modulation transfer functions (MTF's) at a plurality of distinct frequencies.
Owner:AMO MFG USA INC

Zoom lens systems with wavefront coding

Zoom lens systems and methods for imaging incoming rays over a range of ray angles are disclosed. The incoming rays are characterized by at least phase. The zoom lens system includes an optical axis and is characterized by a plurality of modulation transfer functions (MTFs) corresponding at least to the range of ray angles. The zoom lens system includes an optical group disposed along the optical axis, including at least one variable optical element that has a variable focal length selectable between at least two distinct focal length values. The optical group also includes a wavefront coding element. The wavefront coding element alters at least the phase of the incoming rays, such that the plurality of MTFs corresponding to the range of ray angles, for each one of the two distinct focal length values, are less sensitive to misfocus-like aberrations than a corresponding system without the wavefront coding element.
Owner:OMNIVISION TECH INC

Image modulation transfer function (MTF) evaluation-based module motor curve testing method

The invention provides an image modulation transfer function (MTF) evaluation-based module motor curve testing method. An MTF capable of reflecting a defocusing change condition of a lens and testing the consistency of motor characteristics is used as a definition calculation function, MTFs of different positions of a motor are analyzed according to a motor curve fitted by the MTFs, the kinetic characteristics of the motor are judged, and when the motor curve is tested, the positions of the highest points of the motor curve in four corners of a displayed image are simultaneously found, the positions of the four corners are calculated to obtain focal length differences of the four corners, a tilting height difference of the lens and the surface of a sensor is judged, and a tilting angle is calculated. According to the motor curve testing scheme applied by the invention, an MTF testing target and image detection equipment are used for effectively detecting the motor characteristics of a module and bad conditions of tilting of the motor, so that the quality of the product is ensured.
Owner:NINGBO SUNNY OPOTECH CO LTD

Device and method for measuring modulation transfer function of optical lens based on infinite conjugate optical path

The invention relates to a device and method for measuring a modulation transfer function of an optical lens based on an infinite conjugate optical path. The method comprises the following steps: installing a slit target; enabling a to-be-measured lens to be placed in a lens pallet, and placing the lens pallet on a two-dimensional platform; turning on an LED light source, so as to provide illumination for a testing system; searching an optimal focal plane of the to-be-measured lens, and determining the accurate placement position of a slit; adjusting the specific position of an image collection unit, and obtaining the optimal photographing azimuth of a slit image; photographing the tilt image through the to-be-measured lens, and transmitting the slit image to a computer; processing the slit image and obtaining an MTF curve of the to-be-measured lens; precisely controlling the position of the tilt target and the position of the lens pallet through a motor controller, and achieving the continuous online testing of an MTF value of the to-be-measured lens on the computer platform. The method and device can be used for measuring the lens with a big field angle, and solve problems that a conventional infinite conjugate optical system and a conventional edge method are large in optical lens error and poor in stability.
Owner:上海信智精密光学有限公司

Device for measuring modulation transfer function of optical system and method thereof

The invention discloses a device for measuring a modulation transfer function of an optical system and a method thereof. A target generator of the device comprises a knife edge target (4), a light source (1) and an electrical machine (3), wherein the electrical machine drives the knife edge target (4), so that an inclined angle beta is formed between the arrangement direction of a knife edge pixel (12) of the knife edge target (4) and that of a pixel (13) of an area array detector, and the inclined angle meets the following condition: ds=d sin beta, wherein the ds is a sampling distance, and the d is the size of the edge length of the pixel of the area array detector. When measuring, the modulation transfer function, the electrical machine drives the knife edge target (4) to rotate at the angle of beta to perform image data collecting and data processing so as to obtain modulation transfer function of the optical system to be measured. The invention adopts the knife edge target to realize an oversampling technology and improve the sampling rate, thereby being capable of measuring the modulation transfer function of the optical system to be measured without a relay amplifying system, being capable of measuring the maximum frequency which is higher than the Nyquist frequency of the area array detector, simplifying a measuring system, and avoiding complex assembling and correcting work when manufacturing apparatuses.
Owner:SUZHOU UNIV

Fourier domain blur estimation method and system

A method and system for estimating motion blur of an image associated with a moving object. The direction of one-dimensional motion blur may be estimated by inspecting a power spectrum associated with the image. A radon transform with respect to the image power spectrum is computed in the direction of the motion blur. A family of kernels with respect to the one-dimensional motion blur may then be defined utilizing a shutter triggering sequence associated with an image capturing device. The family of kernels may be modeled utilizing a modulation transfer function (MTF). Each modulation transfer function may be compared with the radon transform of the power spectrum associated with the image via a correlation function. The kernel with highest correlation with respect to the radon transform of the image power spectrum may be employed for de-blurring the image.
Owner:HONEYWELL INT INC

Optical system and method for multi-range and dual-range imaging

An imaging system is presented for use in multi-range imaging of an object scene by incoherent light. The imaging system comprises aligned a phase mask section, a single focus lens section, and a pixel detector array (PDA). The phase mask section has a generally non-diffractive, narrowly bounded, phase variation corresponding to a profile of a through-object Modulated Transfer Function (MTF) of the imaging system, where the profile has, at an at least one non-zero spatial frequency, at least two regions of growth leading to the MTF higher than 10%.
Owner:BRIEN HOLDEN VISION INST (AU)

Coding system and method for partial response channels

A system and method for reading data to and writing data from multi-level (M-ary) partial response channels uses a trellis coder to encode an input bit stream sequence into a stream of multi-level data symbols. The data symbols are written to the partial response channel using any of a number of techniques. Preferably, the trellis coder anticipates the modulation transfer function of the partial response channel in encoding the data. Because the partial response channel has its own transfer function, the relationship between the data read from the channel and the actual input data bits is a function not only of the data encoder but also of the partial response channel. Therefore, a decoder specification used to implement the decoder takes into account the effect of the trellis encoder as well as the effect of the partial response channel.
Owner:AVAGO TECH WIRELESS IP SINGAPORE PTE

Optical imaging system

The invention discloses an optical imaging system. The optical imaging system comprises an imaging lens group and an image sensor. The imaging lens group comprises at least three lenses with refraction power, a first imaging surface and a second imaging surface. The image sensor is arranged between the first imaging surface and the second imaging surface. The first imaging surface is a visible light image plane specifically vertical to an optical axis. Additionally, the center visual field of the first imaging surface has the maximum value of modulation transfer factor with first space frequency. The second imaging surface is an infrared light image plane specifically vertical to the optical axis. Additionally, the center visual field of the second imaging surface has the maximum value ofmodulation transfer factor with first space frequency. When a specific condition is met, the distance relative to the imaging focal length of visible light and the distance relative to the imaging focal length of infrared light are reduced. Meanwhile, imaging quality of visible light and infrared light is enhanced.
Owner:ABILITY OPTO ELECTRONICS TECH

Methods for determining refractive corrections from wavefront measurements

A method for determining a refractive correction for an eye involves measuring an optical error of the eye, calculating at least one image quality parameter for a selected spatial frequency of range of spatial frequencies, based on the measured optical error of the eye, and forming a plan for refractive correction of the optical error, based on the calculated image quality parometer. In some embodiments, measuring the optical error involves taking one or more wavefront measurements. In some embodiments, calculating the parameter involves calculation a modulation transfer function.
Owner:AMO MFG USA INC

Image Pickup Optical Lens Assembly

An image pick-up optical lens assembly, sequentially arranged from an object side to an image side along an optical axis, comprises: a first lens element with a positive refractive power having a convex object-side surface, a second lens element with a negative refractive power, a third lens element with a positive refractive power, a meniscus fourth lens element with a positive refractive power having at least one aspherical optical surface, and a fifth lens element with a positive refractive power having at least one inflection point on the optical image-side surface. Additionally, the image pick-up optical lens assembly satisfies several particular conditions. The invention possesses features such as good aberration compensation, well-performed modulation transfer function and short total length of lens assembly applicable for compact cameras and mobile phones.
Owner:LARGAN PRECISION

Method for the simulation of a nonlinear amplifier with envelope memory effect

A method for the simulation of responses of a nonlinear amplifier provides for measuring characteristics of nonlinearity of amplitude and of amplitude / phase-shift conversion of the amplifier, each measurement being made at an amplitude that is constant in input. The method further includes measuring the characteristics at different frequencies, developing the characteristics in sequences of direct transfer functions, computing frequency correctors for the direct transfer functions, measuring characteristics of distortion of amplitude modulation, each measurement being performed by modulating the input amplitude, computing modulation transfer functions reproducing the distortion amplitudes at output according to the input modulation amplitudes and correcting the direct transfer functions when the input amplitude is modulated in order to simulate the envelope memory effect. There is a direct application of the invention to the field of the simulation of high efficiency microwave amplification.
Owner:HANGER SOLUTIONS LLC

Compound modulation transfer function for laser surgery and other optical applications

InactiveUS20080129962A1Mitigates and treats vision conditionMitigates presbyopiaLaser surgeryRefractometersEye laser surgeryLaser surgery
Methods, devices, and systems establish an optical surface shape that mitigates or treats a vision condition in a patient. An optical surface shape for a particular patient can be determined using a set of patient parameters for the specific patient by using a compound modulation transfer function (CMTF). The compound modulation transfer function can include a combination of modulation transfer functions (MTF's) at a plurality of distinct frequencies.
Owner:AMO MFG USA INC

CCD chip modulation transfer function test device and method

InactiveCN103592108AReflect image qualityUnaffected by stray lightTesting optical propertiesMichelson interferometerHe ne laser
The invention discloses a CCD chip modulation transfer function test device and method. The CCD chip modulation transfer function test device mainly comprises a He-Ne laser, an adjustable attenuator, a beam expander, a pinhole filter, a diaphragm, a collimating lens, an improved Michelson interferometer, a camera obscura, an image capture card and a PC data processing system, wherein the He-Ne laser, the adjustable attenuator, the beam expander, the pinhole filter, the diaphragm and the collimating lens are arranged on the incident light path of the improved Michelson interferometer in sequence, and the optical axis of the He-Ne laser, the optical axis of the adjustable attenuator, the optical axis of the beam expander, the optical axis of the pinhole filter, the optical axis of the diaphragm and the optical axis of the collimating lens are arranged on the same straight line, the camera obscura is arranged on the emergent light path of the improved Michelson interferometer, and the PC data processing system is connected with the image capture card which is arranged in the camera obscura and is connected with a CCD. Incident light is processed through the CCD chip modulation transfer function test device to form parallel light, and goes out in a sine interference fringe mode through the improved Michelson interferometer, a sine interference fringe pattern is used as a target, imaging is carried out through the CCD, and a modulation transfer function of the CCD is obtained through a test by using the method of the ratio between the sine interference fringe contrast and the image contrast.
Owner:XIDIAN UNIV

Aberration-free image reconstruction method based on CCD array pixel response function frequency domain calibration

The invention discloses an aberration-free image reconstruction method based on CCD array pixel response function frequency domain calibration, and belongs to the technical field of detectors. A frequency domain model of pixel response functions is established, same-frequency lasers with high stability are utilized for generating sinusoidal interference fringes in a far field, fringe light fields at different spatial frequencies are acquired by changing the relative positions of the same-frequency lasers, frequency domain calibration is conducted on the pixel response functions, calibration coefficients in all orders of all the pixel response functions are acquired respectively, on the basis and in combination with a Fourier optics method, CCD imaging reconstruction is achieved, and aberration-free imaging of a CCD detector can be achieved. According to the method, the pixel frequency domain response functions can be calibrated, meanwhile, tiny offset of the relative positions of all pixels can be calibrated, reconstructed images are free of sample blurs, modulation transfer functions (MTF) approach 1, the contrast ratio is not decreased, and the aberration-free image reconstruction method has the advantages of being high in calibration accuracy and wide in application prospect.
Owner:ACAD OF OPTO ELECTRONICS CHINESE ACAD OF SCI

Spatial light modulator array with heat minimization and image enhancement features

An enhanced spatial light modulator (ESLM) array, a microelectronics patterning system and a projection display system using such an ESLM for heat-minimization and resolution enhancement during imaging, and the method for fabricating such an ESLM array. The ESLM array includes, in each individual pixel element, a small pixel mirror (reflective region) and a much larger pixel surround. Each pixel surround includes diffraction-grating regions and resolution-enhancement regions. During imaging, a selected pixel mirror reflects a selected-pixel beamlet into the capture angle of a projection lens, while the diffraction grating of the pixel surround redirects heat-producing unused radiation away from the projection lens. The resolution-enhancement regions of selected pixels provide phase shifts that increase effective modulation-transfer function in imaging. All of the non-selected pixel surrounds redirect all radiation energy away from the projection lens. All elements of the ESLM are fabricated by deposition, patterning, etching and other microelectronic process technologies.
Owner:NAT TECH & ENG SOLUTIONS OF SANDIA LLC

Method for detecting MTF of hyperspectral remote sensing system based on edge image

The invention relates to a method for detecting a modulation transfer function (MTF) of a hyperspectral remote sensing system based on an edge image. The method takes the influence of an image noise into consideration and comprises the following steps of: selecting edge areas in the horizontal direction and the vertical direction by calculating the modulation degrees of the edges of each wave band of a hyperspectral remote sensing image; performing differential operation on the edge areas to obtain linear spread functions; performing Gaussian function least squares fitting on the linear spread functions to obtain standard deviations; figuring the linear spread functions in the vertical direction and the horizontal direction out by using a median of the standard deviations of the linear spread functions in the vertical direction and the horizontal direction; performing discrete Fourier transform to obtain MTF curves in the two directions; and establishing a two-dimensional MTF matrix of the system by multiplying. The method can select suitable edge areas in the situation of a plurality of wave bands of the hyperspectral remote sensing image, and realize the extraction of the MTF ofthe system when the signal-to-noise ratio of the image is not high.
Owner:BEIHANG UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products