223results about How to "Reduce speckle noise" patented technology

A displaying optical system is disclosed, which is capable of reducing a speckle noise. The displaying optical system comprises a light source emitting coherent light, a scanning device scanning the light, a first optical system causing the light from the scanning device to form an intermediate image, a second optical system causing the light from the intermediate image to form an image on a real display surface, and an optical element arranged between the first and second optical systems. The optical element widens the divergence angle of the light emerged from the optical element toward the second optical system more than the incident angle of the light on the optical element from the first optical system.

A light source device adapted to generate an illumination light beam for illuminating an illuminated surface includes a light source adapted to emit a light beam, a light path conversion member adapted to rotate around an axis perpendicular to a center axis of the light beam emitted from the light source to convert a light path of the light beam emitted from the light source, an overlapping illumination element adapted to overlap a light beam emitted from the light path conversion member on the illuminated surface, the overlapping illumination element having an entrance position of the light bream input to the overlapping illumination element varies with time, and a rotating section adapted to rotate the light path conversion member.

An actuator device for optical deflector includes a base for mounting an optical deflector deflecting a light beam from a light source, at least one piezoelectric actuator translating and vibrating said base; and a supporting body supporting said piezoelectric actuator.

An image projector realizing image projection with high image quality by reducing speckle noise. An image projector comprising a coherent light source, a collimation lens for transforming coherent light emitted from the coherent light source into coherent parallel light, and a projection optical system for projecting coherent parallel light is further provided with a reflection element for reflecting the coherent parallel light and capable of oscillating in parallel with the direction normal to the reflection plane, and a reflection element drive means for causing oscillatory motion of the reflection element.

Disclosed is an ultrasound assembly. The ultrasound assembly includes a garment configured to be affixed to a portion of a living body, and at least one ultrasound transducer having a fixed position on the garment and configured to provide at least one of: produce and receive, ultrasound signals that pass through the living body. The ultrasound assembly further includes an ultrasound processing unit operatively associated with the at least one ultrasound transducer and configured to process the ultrasound signals following passage through the living body, and an ultrasound operator-interface unit operatively associated with the ultrasound processing unit and configured to provide information with respect to the ultrasound signals following passage through the living body.

The present invention provides a surface illuminator having a uniform luminance over a large area by using a laser light source, having a wide color reproduction range, and capable of suppressing a speckle noise, as well as a liquid crystal display using the same. The surface illuminator of the present invention includes the laser light source that emits a laser beam; a beam scan section that deflects and scans the laser beam; and a first plate-shaped light guide that makes the laser beam deflected and scanned by the beam scan section to be incident from an end face portion and making the incident laser beam to emit from a first major surface. Further, the liquid crystal display of the present invention includes a liquid crystal display panel and the surface illuminator, wherein the surface illuminator is used as a backlight illuminator that lights the liquid crystal display panel from backside in this liquid crystal display.

A method for enhancing an ultrasound image is provided, wherein the ultrasound image is segmented into a feature region and a non-feature region, while sufficiently utilizing features contained in the ultrasound image, in particular including some inconspicuous features. The enhanced image according to present invention is not susceptive of the image segmentation and avoid dependence of the enhancement effect on the segmentation template, so as not to produce an evident artificial boundary between the feature region and the non-feature region but to highlight some special information in the image and to remove or mitigate invalid information. Thus the enhanced ultrasound image is particularly suitable for the visual system of the human beings.

An imaging device comprising a plurality of linear imaging arrays and image formation optics that provide field of views corresponding to the plurality of linear image arrays. At least one illumination module produces planar light illumination that substantially overlaps the field of views corresponding to the plurality of linear imaging arrays. Image processing circuitry performs image-based velocity estimation operations, which analyzes pixel data values of a plurality of composite 2-D images each derived from sequential image capture operations of a corresponding one linear imaging array to derive velocity data that represents an estimated velocity of the imaging device with respect to at least one target object disposed in the fields of view. Preferably, the image processing circuitry also produces a first image of portions of the target object(s), the first image having substantially constant aspect ratio, utilizing image transformation operations (or camera control operations) that are based upon the velocity data, to thereby compensate for aspect ratio distortions that would otherwise result from variations in velocity of the imaging device with respect to the target object(s). In addition, the image processing circuitry preferably carries out image-based horizontal jitter estimation and compensation operations, which estimate the horizontal jitter of the imaging device relative to the target object(s) over the image capture operations from which the first image is derived and transform the first image utilizing shift operations that are based upon such estimated horizontal jitter to produce a second image of portions of the target object(s) which compensates for horizontal jitter distortion that would otherwise result therefrom. The first image or second image (or image derived from sharpening the first or second images) is preferably subject to image-based bar code detection operations and / or OCR operations, or output for display to a display device.

A surface illumination apparatus includes: a light source; an end-surface light-guide portion which guides light emitted from the light source in a long-side direction thereof and generates emitted light in a short-side direction thereof; and a light guide plate which allows the emitted light to be incident upon an end-surface portion thereof and emits the incident light from one main-surface portion thereof. The end-surface light-guide portion includes a plurality of polarization control portions arranged in the long-side direction; the plurality of polarization control portions each has a half-wave plate and a polarizing prism; the end-surface light-guide portion emits the emitted light in the form of either of S-polarized light and P-polarized light, using the plurality of polarization control portions; and the light guide plate emits, as output light, either of S-polarized light and P-polarized light from the one main-surface portion.

An optical device for projecting an image is disclosed. In one embodiment, the optical device includes a configurable optical diffuser adapted to produce a diffuse optical beam having a temporally varying pattern of angular divergence. The optical device further includes a plurality of lenslet pairs to shape the diffuse optical beam and a spatial light modulator to spatially modulate the shaped optical beam to project an image.

The embodiment of the invention discloses a laser radar system. The laser radar system comprises a light source module, a modulation light module, a transmitting-receiving module, a detection module and a signal processing module, wherein double-wavelength laser beams are subjected to linear modulation through a modulation light module and are converted into double-frequency linear frequency modulation continuous wave laser beams; one laser beam is used as a local oscillation light beam and the other laser beam is used as signal light which has mutual effect with a detection target; the signal light scatters an echo signal through the detection target; the local oscillation light beam and the echo signal are subjected to coherent beat frequency, so as to obtain double-wavelength Doppler frequency shift difference value information. The laser radar system disclosed by the invention adopts double-wavelength linear frequency modulation laser so that influences, caused by non-linear linear frequency modulation and an atmospheric turbulence effect, on a speed measuring resolution ratio are extremely reduced; distance measurement and speed measurement are carried out on the detection target at the same time; the laser radar system has the advantages of high detection precision, electromagnetic interference resistance, no distance dead zones and the like.

The invention discloses a double-frequency coherent wind lidar based on single-frequency continuous light EOM modulation. The double-frequency coherent wind lidar adopts dual-wavelength laser as a light source, and detects difference of dual-wavelength Doppler frequency shifts through coherent beat frequency to invert speed; and meanwhile, Doppler frequency shift information is extracted by adopting a microwave signal, thereby reducing speckle noise due to detection object unevenness and atmosphere turbulence. Besides, two side frequencies are generated through a single-frequency continuous wave EOM modulation method; double-frequency laser is generated through a method of utilizing a filter to filter center light frequency and filter out the two side frequencies; and the double-frequency laser generation method improves stability of a double-frequency gap, and the double-frequency gap can be controlled flexibly by adjusting trigger signals of modulators. According to the scheme, the dual-wavelength laser is obtained through single-frequency continuous wave EOM modulation, the speed is extracted through a microwave mode, and atmosphere wind speed information is inverted; the stability of the double-frequency gap is improved; and the double-frequency coherent wind lidar has the advantages of high detection precision, anti-electromagnetic interference and compact structure and the like.

A display device of the present invention is provided with a light source (4) for emitting coherent light and displaying an image, and an image receiving part (1) comprising not less than two screens, onto which the coherent light is projected, wherein at least one of the screens constituting the image receiving part (1) is vibrated by an airflow applied to a front or rear surface of the image receiving part (1). Further, the image receiving part (1) has a function of a speaker. Thereby, when coherent light is used as a light source for display, it is possible to suppress spots of light intensity which are called speckle noise and occur due to interference of laser beams reflected at the image receiving part.

Disclosed is an ultrasound assembly. The ultrasound assembly includes a garment configured to be affixed to a portion of a living body, and at least one ultrasound transducer having a fixed position on the garment and configured to provide at least one of: produce and receive, ultrasound signals that pass through the living body. The ultrasound assembly further includes an ultrasound processing unit operatively associated with the at least one ultrasound transducer and configured to process the ultrasound signals following passage through the living body, and an ultrasound-interface unit operatively associated with the ultrasound processing unit and configured to provide information with respect to the ultrasound signals following passage through the living body.

A one-dimensional transverse multiple mode laser is used for a one-dimensional illumination apparatus. A pumping light source, and a laser medium and a wavelength conversion device (nonlinear optical crystal or a nonlinear optical device) which are disposed in a resonator, are provided, and the nonlinear optical crystal or a nonlinear optical device is irradiated with a line beam obtained by exciting the laser medium in an elliptic transverse mode pattern. Then, a one-dimensional light modulation device is irradiated with the wavelength-converted line beam, and scanning with the beam modulated by the modulation device is conducted to produce a two-dimensional image. For example, in a green illumination optical system, in the case where the nonlinear optical device for obtaining visible rays through second harmonic generation from IR rays oscillated by a solid state laser medium has a periodical poling structure, stoichiometric composition periodical poling lithium tantalate having been subjected to vapor transport equilibration is used, whereby reliability is enhanced and a reduction in cost can be achieved through mass production.

A light source apparatus includes a light source unit, a light diffusion element that is provided so as to be rotated about a predetermined rotation shaft and includes a plurality of diffusion regions which are consecutively formed around the rotation shaft, and a motor that rotates the light diffusion element so that a region on which light from the light source unit is incident in the light diffusion element is moved between the plurality of diffusion regions. The plurality of diffusion regions include a first diffusion region, and a second diffusion region which has diffusion characteristics different from diffusion characteristics of the first diffusion region and is provided so as to be adjacent to the first diffusion region.

An image projection module within a housing is operative for causing selected pixels in a raster pattern to be illuminated to produce an image on a display screen of VGA quality. The screen is provided with an array of lenslets to reduce speckle noise in the image.

Described are methods and apparatus for reducing speckle noise in images, such as images of objects illuminated by coherent light sources and images of objects illuminated by interferometric fringe patterns. According to one method, an object is illuminated with a structured illumination pattern of coherent radiation projected along a projection axis. An angular orientation of the projection axis is modulated over an angular range during an image acquisition interval. Advantageously, shape features of the structured illumination pattern projected onto the surface of the object remain unchanged during image acquisition and the acquired images exhibit reduced speckle noise. The structured illumination pattern can be a fringe pattern such as an interferometric fringe pattern generated by a 3D metrology system used to determine surface information for the illuminated object.

An ultrasound imaging method includes scanning an inspected object with a first cluster of ultrasonic beams having a first frequency and a first steer angle, to produce a first sub-frame which is used as a reference frame, and scanning the inspected object with a second cluster of ultrasonic beams having a second frequency different from the first frequency and a second steer angle different from the first steer angle, to produce a second sub-frame. The ultrasound imaging method also includes compounding the second sub-frame and the first sub-frame to form a compounded image, and displaying the compounded image.

The present invention includes methods for the reduction of speckle noise in an image and methods for segmenting an image. Each of the methods disclosed herein includes steps for analyzing the uniformity of a pixel within a plurality of pixels forming a portion of the image and, based on the uniformity of the intensity of the plurality of pixels, adjusting and / or replacing the pixel in order to produce a speckle-noise reduced image, a segmented image, or a segmented and speckle-noise reduced image. The methods of the present invention can employ for example conditional probability density functions, nonlinear estimator functions, convex energy functions and simulated annealing algorithms in the performance of their respective steps.

A method for use in processing an analog signal from a laser scanning bar code reader containing information representative of reflected light from indicia including regions of different light reflectivity, and including narrow and wide elements of the same reflectivity of the indicia, by locating edge transitions between narrow and wide elements; estimating the edge shift associated with such transitions; and changing the edge position to correct for convolution distortion.

A plurality of image projection modules is operative for causing selected pixels in overlapping raster patterns to be illuminated to produce a large size image of high resolution of VGA quality in monochrome or color. The selected pixels in an overlap region of the patterns are illuminated at a lesser intensity to provide uniform brightness over the image. Multiple single mode lasers, or a multimode laser with an aperture stop, are employed to increase laser output power. Speckle noise is reduced by controlling the optical transmission characteristic of a projection screen. Three-dimensional images are generated by moving the screen. Cross-coupling between drive and feedback mechanisms in image projection is reduced for better image quality.

The light-emitting device 100 of the present invention has a first cladding layer 106; an active layer 108 formed above the first cladding layer 106; and a second cladding layer 110 formed above the active layer 108, wherein the active layer 108 has a first side surface 107, and a second side surface 109 parallel to the first side surface 107; at least a portion of the active layer 108 constitutes a gain region 180; the gain region 180 has a first end surface 140 disposed on the first side surface 107 side and a second end surface 142 disposed on the second side surface 109 side, and extends from the first end surface 140 to the second end surface 142 in the direction inclined to the normal to the first side surface 107 as viewed from above; the second end face 109 is orthogonal to the direction in which the gain region 180 extends as viewed from above; a reflecting part 150 is disposed on the second end face 109; and a part of the light 10 generated in the gain region 180 is reflected in the reflecting part 150 disposed on the second end face 142 and is emitted from the first end surface 140.

A wavelength conversion laser device includes a laser light source which emits a laser beam, two reflective surfaces which reflect therefrom a laser beam, a wavelength converter provided between the two reflective surfaces, which converts a laser beam into a wavelength-converted laser beam, and condensing optics which condense the laser beams to be injected between the two reflective surfaces, wherein at least one of the two reflective surfaces has a curvature for reflecting a laser beam to be re-injected into the wavelength converter between the two reflective surfaces repeatedly while forming multi paths of laser beams injected into the wavelength converter at different incident angles, and the condensing optics are arranged to disperse beam waists of the laser beams in the wavelength converter, which reciprocate between the two reflective surfaces.

The invention discloses a laser driving circuit, a laser driving method, a projector apparatus and an apparatus which uses laser light. The laser driving circuit includes a plurality of laser driving video current generation circuits configured to generate a plurality of kinds of laser driving current for driving a plurality of laser light sources configured to emit laser light having wavelengths different from each other based on an inputted video signal; a high frequency superposition section configured to superpose a high frequency signal having a frequency higher than a frequency band of the video signal on the laser driving current generated by the laser driving video current generation circuits; and a waveform correction section configured to correct a waveform of the high frequency signal.