A rear projection screen which eliminates speckle by only linear diffuser surface motion. One of a pair of closely spaced plates of the rear projection screen is maintained fixed while the other plate is driven such that it has a linear motion relative to the fixed plate. The plates are optically transparent and have their facing surfaces etched or coated to provide adjacent diffusing surfaces. The driven screen is supported by L-shaped spring metal straps thereby providing a strong plate support assembly which can operate at low noise levels and with low drive-power requirements.
A projection display apparatus comprises a compact CRT, a projecting lens for projecting an enlarged image of the CRT, a Fresnel lens having a converging effect, a lenticular sheet as a diffusing plate. An image that has been enlarged by the projecting lens and passed through the lenticular Fresnel lens is formed on the lenticular sheet. The apparatus further comprises a displacing mechanism for displacing the Fresnel lens, and a display mechanism for displaying information related to the direction and extent of displacement of the Fresnel lens displaced by the displacing mechanism.
A communication or control cable having one or more supporting elements made of (a) high-molecular weight reinforcing fibers or filaments having a modulus of elasticity>100 GPa, which are firmly joined to one another by means of (b) a high-molecular weight, crosslinked resin.
A method and apparatus for reducing laser speckle in a laser illuminated system where a line illumination produced by a laser is scanned across a diffuse service is preferably incorporated in a display apparatus where a two dimensional image is produced on a display screen. The display apparatus includes a light modulator, a wavefront modulator, and a projection/scanning optical arrangement. The light modulator modulates a laser illumination to form a line image made up of a linear array of pixels. The wavefront modulator varies a spatial phase across a width of the line image thus forming a phase modulated wavefront. The projection/scanning optical arrangement projects the line image onto the display screen and scans the line image over the display screen. The phase modulated wavefront produces multiple speckle patterns that are averaged as the line image is scanned and, thus, produces the reduced laser speckle.
A projection surface includes scattering microparticles that are in constant motion in relation to each other and to a source of laser radiation in a laser projection system. The microparticles reduce the formation of spots that normally occur when viewing the contents of images which are uniformly illuminated by means of laser projection and which are reflected off a projection surface. The microparticles are formed in a suspension fluid and move due to Brownian molecular motion. The fluid is warmed to further increase motion of the microparticles or a piezoelectric force or other mixing mechanism is used to cause turbulence that also increases motion and mixing of the microparticles.
A method for displaying an image including: forming at least three light beams by diffraction at a single linear light modulator, wherein the at least three light beams have substantially equal intensity and are substantially the same color; projecting the at least three light beams toward a display surface to form an image line; and, scanning the image line across the display surface to form an image thereby.
