64results about How to "Reduce Speckle Contrast" patented technology

An enhanced electroluminescent sign containing a volumetric, anisotropic scattering element to control the angular spread of light from the sign and the spatial luminance uniformity of the sign. The anisotropic scattering element contains one or more regions of asymmetrically-shaped light scattering particles. The angular spread of light leaving a sign from a light emitting source can be efficiently controlled by using a thin, low cost, volumetric, anisotropic scattering elements to angularly and spatially distribute light, permitting the reduction in number of light sources, a reduction in power requirements, or a more tailored viewing angle.

Apparatus for inspection of a sample includes a radiation source, which is adapted to direct optical radiation onto an area of a surface of the sample, and a plurality of image sensors. Each of the image sensors is configured to receive the radiation scattered from the area into a different, respective angular range, so as to form respective images of the area. An image processor is adapted to process at least one of the respective images so as to detect a defect on the surface.

An enhanced light fixture containing a volumetric, anisotropic diffuser to control the spatial luminance uniformity and angular spread of light from the light fixture is disclosed. The anisotropic diffuser provides increased spatial luminance uniformity and efficient control over the illuminance such that power reductions, reduced cost or reduced size may be achieved. The anisotropic diffuser contains one or more regions of asymmetrically shaped light scattering particles. The spread of illumination of light from a light emitting source can be efficiently controlled by using a thin, low cost, volumetric, asymmetric diffuser to direct the light in the desired direction. This allows the reduction in number of light sources, a reduction in power requirements, or a more tailored illumination. When the anisotropic diffuser is used in combination with a waveguide to extract light, the light is efficiently coupled out of the waveguide in a thin, planar surface. This transmissive diffuser can be coupled to a reflecting element such that the resulting combination is a light reflecting element with a desired asymmetric light scattering profile.

An enhanced light fixture containing a volumetric diffuser to control the spatial luminance uniformity and angular spread of light from the light fixture is disclosed. The volumetric diffuser provides increased spatial luminance uniformity and efficient control over the illuminance such that power reductions, reduced cost or reduced size may be achieved. The volumetric diffuser contains one or more regions of volumetric light scattering particles. The spread of illumination of light from a light emitting source can be efficiently controlled by using a thin, low cost, volumetric, diffuser to direct the light in the desired direction. This allows the reduction in number of light sources, a reduction in power requirements, or a more tailored illumination. When the volumetric diffuser is used in combination with a waveguide to extract light, the light is efficiently coupled out of the waveguide in a thin, planar surface. This transmissive diffuser can be coupled to a reflecting element such that the resulting combination is a light reflecting element with a desired light scattering profile.

An enhanced light fixture containing a volumetric, anisotropic diffuser to control the spatial luminance uniformity and angular spread of light from the light fixture is disclosed. The anisotropic diffuser provides increased spatial luminance uniformity and efficient control over the illuminance such that power reductions, reduced cost or reduced size may be achieved. The anisotropic diffuser contains one or more regions of asymmetrically shaped light scattering particles. The spread of illumination of light from a light emitting source can be efficiently controlled by using a thin, low cost, volumetric, asymmetric diffuser to direct the light in the desired direction. This allows the reduction in number of light sources, a reduction in power requirements, or a more tailored illumination. When the anisotropic diffuser is used in combination with a waveguide to extract light, the light is efficiently coupled out of the waveguide in a thin, planar surface. This transmissive diffuser can be coupled to a reflecting element such that the resulting combination is a light reflecting element with a desired asymmetric light scattering profile.

A method and apparatus for reducing speckle in a laser illumination system uses a despeckle device including an optical retarder providing an odd integer multiple of substantially half-wave retardation for light emitted from a coherent laser in the laser illumination system. The near half-wave optical retarder has a substantially constant retardance and a spatially varied slow axis. The spatially varied slow axis imposes a phase mask on the beam of light, which provides sub-resolution optical phase modulation to a resolution spot on the detector. The near half-wave optical retarder is actuated mechanically or electrically to vary the sub-resolution optical phase modulation within an integration time of the detector.

A multi-region light scattering element with the optical characteristics of low speckle, high resolution high contrast, and high gain when used as an imaging element without any resulting loss of transmission or brightness with viewing angle. The multi-region light scattering element contains at least one region asymmetrically shaped light scattering features that are separated from a second light scattering region by a non-scattering region. In one embodiment, one or more of the regions contains particles that are asymmetrically shaped that improve the optical performance. In one embodiment, asymmetric particles are located in two regions separated by a non-scattering region with the particles within each region substantially aligned along an axis and the two axes are substantially perpendicular to each other. Methods for production of the screen element are also described.

A coherent beam moves across a stationary line generator, allowing the speckle pattern projected through the diffuser onto the surface—for example using a MEMS mirror, or another arrangement that is free of a moving mass, such as solid state beam deflector (e.g. an AOM). Where an image sensor is employed, such as a DS, the beam is moved at a speed of at least ½ cycle per image frame so that the full length of the line within the imaged scene is captured by the image sensor. The distance traversed on the diffuser provides sufficient uncorrelated speckle patterns within an exposure time to average to a smooth line. The MEMS mirror can be arranged to oscillate in two substantially orthogonal degrees of freedom so that the line is generated along a first direction and the line moves along the working surface in a second direction.

A multi-region light scattering element with the optical characteristics of low speckle, high resolution high contrast, and high gain when used as an imaging element without any resulting loss of transmission or brightness with viewing angle. The multi-region light scattering element contains at least one region asymmetrically shaped light scattering features that are separated from a second light scattering region by a non-scattering region. In one embodiment, one or more of the regions contains particles that are asymmetrically shaped that improve the optical performance. In one embodiment, asymmetric particles are located in two regions separated by a non-scattering region with the particles within each region substantially aligned along an axis and the two axes are substantially perpendicular to each other. Methods for production of the screen element are also described.

A system and method for reducing peak power of a laser pulse and reducing speckle contrast of a single pulse comprises a plurality of elements oriented to split and delay a pulse or pulses transmitted from a light emitting device. The design provides the ability to divide the pulse into multiple pulses by delaying the components relative to one another. Reduction of speckle contrast entails using the same or similar components to the power reduction design, reoriented to orient received energy wherein angles between the optical paths are altered such that the split or divided light energy components strike the target at different angles or different positions. An alternate embodiment for reducing speckle contrast is disclosed wherein a single pulse is passed in an angular orientation through a grating to create a delayed portion of the pulse relative to the leading edge of the pulse.

A method of operating a laser source comprising is provided. The method reduces speckle contrast in a projected image by creating a plurality of statistically independent speckle patterns. The method comprises generating a plurality of sub-beams that define an optical mode. The method further comprises controlling the phase of selected sub-beams to continuously sequence the laser source through a plurality of orthogonal optical modes. The plurality of orthogonal modes create a corresponding number of statistically independent speckle patterns, thus reducing speckle contrast in a image projected using the laser source by time averaging.

Exemplary systems and methods for generating information associated with at least one portion of a sample can be provided. For example, it is possible to receive from the at least one portion and / or transmit to at least one electromagnetic radiation to the portion. At least one first wave front of the electro-magnetic radiation received from and / or transmitted to the portion can be provided to generate at least one first transmitted wave front. After the first transmitted wave front is generated, at least one characteristic of at least one second wave front of the electromagnetic radiation received from and / or transmitted to the portion can be modified to generate at least one second modified wave front which is different from the first transmitted wave front. Further, the information can be generated based on the first transmitted wave front and the second modified wave front.

A beam delivery system of a projection exposure system comprises a laser generating a beam of laser light from a plurality of longitudinal laser modes in a cavity, wherein light generated by a single longitudinal laser mode has an average line width λlat, wherein the laser light of the beam has, at each of respective lateral positions of the beam, a second line width λlat corresponding to lateral laser modes, and wherein the laser light of the beam has, when averaged over a whole cross section thereof, a line width λb corresponding to plural lateral laser modes, and wherein λm<λlat<λb, and wherein an optical delay apparatus disposed in the beam provides an optical path difference Δl, wherein0.8·λ02(2·Δλl)<Δl<1.8·λ02(2·Δλl),wherein λ0 is an average wavelength of the light of the first beam of laser light, and Δλlat represents the second line width.

A method and apparatus for reducing speckle in a laser illumination system uses a despeckle device including an optical retarder providing an odd integer multiple of substantially half-wave retardation for light emitted from a coherent laser in the laser illumination system. The near half-wave optical retarder has a substantially constant retardance and a spatially varied slow axis. The spatially varied slow axis imposes a phase mask on the beam of light, which provides sub-resolution optical phase modulation to a resolution spot on the detector. The near half-wave optical retarder is actuated mechanically or electrically to vary the sub-resolution optical phase modulation within an integration time of the detector.

Laser scanner projection systems that reduce the appearance of speckle in a scanned laser image are provided. The laser projection system includes a visible light source having at least one laser, a scanning element and a system controller. The system controller is programmed to generate a scanned laser image. The system further includes a first lens that focuses a scanned output beam onto an intermediate image and a second lens that projects the intermediate image onto a projection surface. A periodic phase mask having a period that is approximately equal to or greater than the beam waist diameter of the scanned output beam is positioned at the intermediate laser image. The period of the periodic phase mask is such that the projection of the scanned output beam jumps progressively from pixel to pixel, thereby reducing speckle contrast in the scanned laser image.

The invention discloses a speckle-free three-primary-color laser light source, which comprises a plurality of laser modules, an energy-transfer fiber, a converging lens, a diffusion sheet and a rectangular integrating rod, wherein an output fiber outlet of each laser module corresponds to one collimating lens. According to the speckle-free three-primary-color laser light source, light emitted from the plurality of red, green and blue laser modules is combined and subjected to homogenizing and speckle-eliminating treatment to obtain high-brightness, speckle-free and high-uniformity lighting light required for projection and display.

The present disclosure describes, among other things, a reduced speckle contrast microelectromechanical system. One exemplary embodiment includes micromechanical structures configured to form a uniform reflective surface on a substrate, an elastic substance coupled to the substrate, and an energy source that applies a voltage to the elastic substance to alter the shape of the surface of the substrate, for example, by about 10% to about 25% of a wavelength of light projected onto the substrate at a frequency of at least 60 Hz. Another exemplary embodiment includes micromechanical structures formed on a surface of a substrate, a reflective diaphragm connected to the substrate, an elastic substance coupled to the diaphragm, and an energy source that applies a voltage to the elastic substance to vibrate the diaphragm at a frequency of at least 60 Hz.

The invention discloses a device and method for inhibiting laser speckles and a laser display projection system. The device comprises a plurality of noncoherent lasers, an optical fiber coupler and an optical fiber bundle. Multiple paths of light beams output by the lasers are coupled into sub optical fibers of the optical fiber bundle through the optical fiber coupler. The light beams transmitted in the sub optical fibers are called sub light beams. The adjacent sub light beams of the same frequency output by the output end of the optical fiber bundle have the preset distance in space. The sub light beams of the same frequency irradiate a screen at different angles through a projection system due to the set preset distance, so that speckle patterns observed by human eyes are independent from one another. According to the device, the coherence of the light beams is lowered through the noncoherent lasers, and thus the speckle contrast is lowered; the sub light beams are distributed according to the angle diversification of the speckles at the output end of the optical fiber bundle, and the independent speckles are superposed in the space to lower the speckle contrast; the speckle inhibiting effects of the two methods can be superposed, and the speckle contrast is lowered to a greater extent.

The invention discloses a laser light source and a laser projection device. The laser light source provided by an embodiment of the present invention comprises lasers, a light collection device, a rotation wheel, and a light uniformizing component; the lasers can emit light of at least two colors; excitation light and laser light can be transmitted through the light collection device and arrive atthe rotation wheel; the light collection device reflects laser light reflected by the rotation wheel and fluorescent light; the rotation wheel includes a substrate; a diffuse reflection portion and afluorescence portion are arranged on the substrate; the diffuse reflection portion reflects the laser light transmitted by the light collection device to the light collection device; excited by the transmitted excitation light, the fluorescence portion generates fluorescent light; the fluorescence portion is coated with at least one kind of fluorescent powder with same colors as the lasers; whenbeing excited by the excitation light, the at least one kind of fluorescent powder turns on the lasers of which the colors are corresponding to the colors of the fluorescent powder; and the light uniformizing component receives the laser light and the fluorescent light reflected by the light collection device and uniformizes the received laser light and the fluorescent light. Therefore, the rotation wheel realizes the mixed output of the laser light and fluorescent light; and the diffuse reflection portion can diffusely reflect a light spot formed by laser light entering the diffuse reflectionportion, and therefore, speckle elimination can be facilitated.

A beam delivery system of a projection exposure system comprises a laser generating a beam of laser light from a plurality of longitudinal laser modes in a cavity, wherein light generated by a single longitudinal laser mode has an average line width λlat, wherein the laser light of the beam has, at each of respective lateral positions of the beam, a second line width λlat corresponding to lateral laser modes, and wherein the laser light of the beam has, when averaged over a whole cross section thereof, a line width λb corresponding to plural lateral laser modes, and wherein λm<λlat<λb, and wherein an optical delay apparatus disposed in the beam provides an optical path difference Δl, wherein0.8·λ02(2·Δ⁢⁢λl)<Δ⁢⁢l<1.8·λ02(2·Δ⁢⁢λl),wherein λ0 is an average wavelength of the light of the first beam of laser light, and Δλlat represents the second line width.

A projection device includes a diffuser and a light source system. The light source system includes a light source, a dichroic element, an actuator, and a reflector. The light source generates a light beam that is directed to the dichroic element. The dichroic element forms first and second individual light beams from the light beam. The first individual light beam is transmitted to the diffuser. The second individual light beam is reflected from the reflector to the diffuser. The actuator is fixed to the reflector and has a removal frequency exceeding 20 Hz.

The invention discloses a light source system for eliminating laser speckles. The light source system comprises a laser light source module which is used for generating laser beams including red light, green light and blue light; a beam scanning mechanism which is used for reflecting the laser beams, wherein the beam scanning mechanism periodically swings so that the laser beams are enabled to form the divergent surface light source through scanning; a first lens which is used for converting the divergent surface light source into a parallel surface light source; a micro-lens array group which is used for converting the parallel surface light source into multiple divergent surface beams; and a second lens which is used for converting the multiple divergent surface beams into multiple parallel surface beams, wherein the multiple parallel surface beams are converged at the focus of the second lens. The invention also discloses a projection device comprising the light source system. The light source system is simple in structure and easy to implement and can effectively reduce or eliminate the laser speckles.

The invention relates to an optical sensor device (1) for determining a blood perfusion parameter of a user. A light source (2) provides coherent light for scattering in a tissue sample (11) and a light detection unit (3) receives scattered coherent light in a re-emission geometry, the light detection unit (3) comprising plural light detection elements (32a; 32b) for capturing light intensity values in increasing distances from the light source (2) in accordance with different tissue depths. An evaluation unit (10) determines contrast values based on the captured light intensities, determines one motion-corrected value of the blood perfusion parameter based on the contrast values associated with the different tissue depths. Moreover, the invention relates to a method determining at least one blood perfusion parameter using the sensor device (1).

The invention provides an area array sweep frequency measurement device and method, and belongs to the technical field of laser ranging. A beam splitter decomposes a converged light beam into reflected light and transmitted light; during use, a measured object reflects the reflected light to form signal light; a reflecting element is used for reflecting the transmitted light; a second dichroscope is used for decomposing the reflected transmitted light into reference light and wide-spectrum light; a spectrograph is used for acquiring spectral information through the decomposed wide-spectrum light; a camera is used for collecting an interference image formed by interference of the signal light and the reference light; an acquisition control unit can analyze the surface topography of the measured object according to the interference image and the compensation information; vibration information is obtained according to the spectral information and used for controlling a piezoelectric ceramic displacement table to move, and compensation information is obtained. Through superposition of a plurality of independent speckles, the effect of reducing the speckle contrast is achieved; meanwhile, an optical anti-shake function is achieved, and the laser ranging accuracy is improved.

The invention discloses a speckle removing device of laser display, and relates to the technical field of laser display. The device comprises laser sources and optical components, at least part of the optical components is placed in the light extraction directions of the laser sources, the optical components of transmission type are rotatable, and comprise uneven laser incidence planes respectively, and when the optical components rotate, laser beams emitted by the laser sources continuously pass the laser incidence planes. The rotary optical components are additionally arranged behind the laser sources to change the spatial coherence of laser, enable speckle to overlap continuously in the integration time, reduce the contact of speckles, and weaken the speckles. In addition, the laser sources are constant in the speckle removing process, so that the speckles can be effectively removed on the premise that the laser power and quality of laser beams are ensured, and the display quality is improved.

The invention relates to the technical field of display which takes coherent light as a light source, in particular to a Mie scattering and field-induced deformation polymers-based speckle eliminating device, and solves the problems that a speckle effect is poor, a realization structure is complex, the device is easy to damage, the cost is high and the like in a conventional speckle eliminating method. The device comprises an optical reflection cavity on which an incident light coupling device and a transmission exit surface are arranged; the inner wall, besides the inner wall of the transmission exit surface, of the optical reflection cavity is the inner wall of a mirror surface; a transparent solid substance filling the overall optical reflection cavity is arranged in the optical reflection cavity; medium particles of which the dimension can cause the Mie scattering of an incident laser are dispersed in the transparent solid substance, wherein the transparent solid substance is a field-induced deformation polymer; and the optical reflection cavity is matched with an actuating device which is used for generating an external field required by the polymer in the cavity. The device is easy to implement, along with a reasonable and compact structure, a good speckle eliminating effect, low cost, high laser utilization rate, stable performance, safety, reliability and light homogenizing function.

The embodiment of the invention discloses an optical rotor and device and method for inhibiting laser speckle based on the optical rotor. The device comprises a linear polarized light generator, an optical rotor, a modulating power supply and an imaging display system; the linear polarized light generator is used for generating linear polarized light; the optical rotor connects the linear polarized light generator with the modulating power supply; the optical rotor can be driven by the magnetism generated by modulating pulse pressure of the modulating power supply to rotate the linear polarized light sent by the linear polarized light generator in the polarizing direction, so as to obtain output linear polarized light which is orthogonal to the inputted linear polarized light; the modulating power supply is connected with the optical rotor and used for providing the modulating pulse pressure to the optical rotor; the imaging display system is used for projecting and displaying the linear polarized light outputted by the optical rotor. According to the technical scheme, the device has the advantages of being simple in structure, flexible and convenient to modulate, and wide in applicable scope; the device can be used in match with other speckle removing technologies so as to achieve a good speckle inhibiting and dispersing effect.