4results about How to "Reduce Speckle Contrast" patented technology

The application relates to a laser projection device and a laser projection system. A depolarizer component is additionally arranged on a laser display light path between a light source and a light modulation component, so that birefringence and interference effects occur in the depolarizer component, and polarized light is converted into random polarized light. Birefringence caused by lens stress in the light modulation component usually has a fixed fast and slow axis direction, which can affect the polarization state of light passing through the lens. In the embodiments provided by the application, the depolarizer component can rotate around the light beam propagation direction in the working state. When the light beam passes through the lens each time, the polarization direction of the light changes relative to the axis of the stress birefringence. The phase delay caused by the stress has different effects in different directions, and the effects are offset after time averaging, so that the negative influence of the birefringence effect caused by the lens stress on the depolarization effect of the depolarizer component can be reduced, and the speckle contrast can be greatly reduced, and the speckle suppression effect is improved.

The application discloses a kind of laser speckle suppression device and method, belong to optical technology field, by laser light source, collimating lens, half-transmission half-reflection mirror, light splitting film layer array, detector is formed, laser light source output coherent laser;Collimating lens is collimated after laser beam, again by half-transmission half-reflection mirror vertical injection light splitting film layer array;Light splitting film layer array will incident beam be divided into multiple non-coherent and light intensity equal sub-beam.The present application is static speckle suppression device, does not need power supply and drive, device structure is compact, small in size, low energy consumption, long service life;This device structure is simple, and the effect of speckle suppression is good, can be divided into N beam light intensity equal non-coherent light for laser beam, at most the speckle contrast of laser is reduced to 1 / N of original 1 / 2 .

The invention discloses a light source evaluation and selection method suitable for laser display, relates to the technical field of laser display, and aims to solve the problems that in the prior art, when speckle suppression is carried out by using multiple light source schemes in laser display, the color gamut expression of a display system is influenced, and the color gamut and brightness of the system are possibly sharply reduced. Therefore, the laser display advantage is lost; according to the invention, a corresponding speckle contrast expression is obtained through a light source spectrum; chromaticity coordinates corresponding to the light source types are obtained; judging whether light source brightness limitation exists or not; if yes, calculating a three-dimensional color gamut volume ratio according to the corresponding chromaticity coordinates; if not, calculating a plane color gamut coverage rate ratio according to the corresponding chromaticity coordinates; obtaining an evaluation factor according to the color gamut ratio and the speckle contrast expression; selecting and evaluating corresponding evaluation factors; the speckle suppression and color gamut performance of the light source can be comprehensively evaluated, the method is suitable for optimal configuration selection in different scenes, and the light source selectivity in laser display is greatly improved.

This invention discloses a low speckle contrast, high reflectivity aerogel optical material, its preparation method, and its applications. The low speckle contrast, high reflectivity aerogel optical material comprises a transparent aerogel matrix serving as an optical framework; and light-scattering nanoparticles dispersed therein. The aerogel optical material has a first surface and a second surface arranged opposite to each other in the thickness direction. From the first surface to the second surface, the light-scattering nanoparticles exhibit a graded distribution in particle size, with the particle size gradually increasing. This invention utilizes the ultra-low refractive index of the aerogel to suppress Fresnel interface reflection, improve luminous efficiency, and provide a high refractive index difference. Through a "sedimentation-gel synergy" process, a gradient structure with a continuous particle size distribution in the thickness direction is constructed in situ within a single matrix, simultaneously achieving extremely low speckle contrast (<4%) and high light utilization (average visible light reflectivity >90%), while also possessing advantages such as ultra-light weight and good environmental stability.