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.

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.

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 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 λ_lat, wherein the laser light of the beam has, at each of respective lateral positions of the beam, a second line width λ_lat 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 λ_b corresponding to plural lateral laser modes, and wherein λ_m<λ_lat<λ_b, and wherein an optical delay apparatus disposed in the beam provides an optical path difference Δl, wherein

wherein λ₀ is an average wavelength of the light of the first beam of laser light, and Δλ_lat represents the second line width.

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 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.

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 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.