100results about How to "Reduce speckle effect" patented technology

A method of performing a DFT (discrete Fourier transform) or a DFT derived transform on data, comprising: providing spatially modulated light having spatial coherence, said spatially modulated light representing the data to be transformed; Fourier transforming said spatially modulated light, using an at least one optical element; and compensating for at least one of a scaling effect and a dispersion effect of said at least one optical element, using an at least one dispersive optical element.

Speckle effect in scanning display systems that employs polarized phase-coherent light is reduced by depolarizing the phase-coherent light using a depolarizer and scanning the depolarized light for producing desired images.

Apparatus for reducing speckle, including a first coherence-reducing component, having a first array of transparent first elements arranged to receive different, respective first portions of a collimated light beam that is incident on the first component, the first elements generating different, respective optical lengths with respect to the light beam passing therethrough and outputting the respective first portions as respective first collimated sub-beams. The apparatus further includes a second coherence-reducing component, having a second array of transparent second elements arranged to receive different, respective second portions of each of the first collimated sub-beams of the light beam, the second elements generating different, respective optical lengths with respect to the light beam passing therethrough and outputting the respective second portions as respective second collimated sub-beams. The apparatus also includes a light combiner, which is arranged to combine the second collimated sub-beams into a collimated output beam.

The invention discloses a speckle eliminating part. The speckle eliminating part comprises a first diffusion sheet, a second diffusion sheet and a driving part; the first diffusion sheet and the second diffusion sheet have a public rotating shaft; the first diffusion sheet is a wedge-shaped lens; the included angle between at least one surface of the wedge-shaped lens and the public rotating shaftis not equal to 90 DEG; the diversity of the divergence angle of incident laser beams after continuously passing through the two diffusion sheets can be improved; the random phase generation probability is increased; random phases can generate random speckle patterns; therefore, the laser beam coherence is reduced; and the speckle effect is greatly reduced through human eye integration. The invention further provides a laser source and laser projection device using the speckle eliminating part.

The invention proposes a light-source device, in particular for use in a micromirror device, comprising a first red light source for emitting light in the red spectral range, a second red light source for emitting light in the red spectral range, a green light source for emitting light in the green spectral range and a blue light source for emitting light in the blue spectral range, and superposition means, wherein the superposition means are arranged in such a way that the light from the first red light source, the light from the second red light source, the light from the blue light source and the light from the green light source are superposed in a collinear manner to form a common light beam, the light from the first red light source having a wavelength different from that of the light from the second red light source.