A digital video system (20) including a computer (22) connected via a network (28) to a number of video servers (26) and cameras (24). The computer (22) includes a program that provides a grid of display windows, each of which displays an image received from the camera associated with that window. The program sequentially polls each camera, accessing and displaying an images from the camera in its associated window. The program can access the cameras (24) at different frame rates. The program stores image streams in a single file, concatenating each successive image onto the end of the file. The file is then indexed using SOI and EOI markers to permit fast access to individual images within the file. The program can monitor received video and automatically start recording upon detecting motion within the video stream. Motion detection is implemented by comparing color component values for pixels from different images.

Digital video system using networked cameras

An optical switch element is described, which includes a fixed layer disposed outwardly from a substrate and a movable mirror assembly disposed outwardly from the fixed layer. The moveable mirror assembly is operable to move relative to the fixed layer responsive to a voltage applied to the movable mirror assembly. In a particular embodiment, the movable mirror assembly includes an inner strip spaced apart from the fixed layer by a first distance and an outer strip disposed approximately adjacent to the inner strip and spaced apart from the fixed layer by a second distance which is greater than the first distance. The optical transmission of the optical switch element changes depending on the position of the movable mirror assembly.

Micromechanical optical switch

A projection display system. The projection system includes a light source, illumination optics that are capable of splitting the light from the source into individual color bands, and folding mirrors. The folding mirrors operate to direct the color bands to a reflective element that has a contoured surface. The contoured surface of the reflective element causes the light to form into scanning rasters that are recombined and sent to a spatial light modulator. The spatial light modulator is typically made up of a panel of individually addressable elements. If the spatial light modulator requires polarized light, a polarizing beam splitter and quarter-wave plate are included as part of the illumination optics.

Single panel color video projection display using reflective banded color falling-raster illumination

A color splitting prism assembly (100) comprised of three prisms. Each a dichroic filter at an interface (112) between a first and second of the three prisms reflects a first primary color component of a white light beam passing through the prism assembly. The first primary color component is directed to a first modulator (118). The remaining portions of the white light beam enter a second prism (108) and strike a second dichroic filter at the interface between (124) the second and third prisms. The second dichroic filter separates a second primary color component from the white light beam leaving a third primary color component to travel through the third prism (110) to a third modulator. The second primary color component of the white light beam is directed to a second modulator (128). Light modulated by the first and third modulators travels through the prisms at a slightly different angle than the unmodulated light and therefore reacts differently upon striking the first dichroic filter for the second time. Portions of the light modulated by the first and third modulator travel toward the second modulator (128). An additional filter on or near the exit face (126) of the second prism (108) prevents light in the first and third primary color components from reaching the second modulator (128) and heating the second modulator (128). The light rejected by the additional filter is dispersed by ground glass surfaces of the color splitting prism assembly.

Bandpass filter to reduce thermal impact of dichroic light shift

This book provides the reader with an understanding of what color is, where color comes from, and how color can be used correctly in many different applications. The authors first treat the physics of light and its interaction with matter at the atomic level, so that the origins of color can be appreciated. The intimate relationship between energy levels, orbital states, and electromagnetic waves helps to explain why diamonds shimmer, rubies are red, and the feathers of the Blue Jay are blue. Then, color theory is explained from its origin to the current state of the art, including image capture and display as well as the practical use of color in disciplines such as computer graphics, computer vision, photography, and film.

Color Imaging: Fundamentals and Applications

Distortion optics are used to efficiently couple a spiral color wheel and an orthogonal modulator. Light 602 from a light source enters an aperture in a reflective end of a recycling integrator rod 604. The light travels through the rod and exits the end of the rod adjacent a sequential color filter 606, shown as a spiral color wheel. The shape of the light beam 608 exiting the integrator rod 604 is determined by the shape of the exit aperture of the integrating rod 606. The exit aperture of the integrating rod 606 typically is formed by a reflective exit aperture on the exit face. A cross section of the light beam 608 exiting the sequential color filter includes several bands of filtered light, one for each of the filter segments of the color wheel illuminated by the light beam. The curvature of the color bands makes it difficult for a row addressed spatial light modulator to efficiently use the light. Illumination system 600 eliminates or mitigates this problem by distorting the light from the integrating rod to straighten the curved borders between the adjacent filter segments. The light 608 from the sequential color filter 606 is distorted by distortion optics 610, 612 to make the boundaries between the white or primary colored light segments align with the rows of the spatial light modulator 614.

Illumination system for scrolling color recycling

A method of and system for improving the saturation of the primary colors in a display system. A color correction filter ( 218 ) removes unwanted wavelengths from a beam of light. A color splitter ( 228 ) separates the beam of light into at least three primary color beams of light. The primary color beams of light are selectively modulated by spatial light modulators ( 220, 222, 224 ) before passing through a projection lens ( 104 ) which focuses the beams of light onto an image plane.

Color correction filter for displays

A method and system for improving the contrast ratio of a projected image An asymmetric aperture stop improves the contrast ratio of a projected image Using slightly offset projection, the majority of the on-state projection light from the modulator array passes through a region that is not centered in the projection lens pupil The blocked region of the asymmetric aperture is oriented toward the illumination path and away from the specular reflection path The asymmetric aperture is able to block a significant portion of the diffracted light using the blocked region, without blocking much of the desired projection light passing through the remainder of the aperture The result is that dark regions of the image become significantly darker, while light regions remain about the same The same effect occurs without offset illumination

High contrast projection

Scrolling color has long been a goal of the projector industry, as it enables the most efficient use of light in a single panel display. Current methods of implementing scrolling color use the techniques of splitting the light into primary colors, and manipulating that light on the modulator. The authors present the techniques of dynamic filtering and sequential color recapture (SCR) to achieve the same result with no moving components other than a color wheel, showing that the efficiency of 3-modulator systems can be approached with one modulator. Analysis of the technique applied to DLP™ projection displays, and results of prototype projection systems using the techniques, will be presented.

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40.2: Sequential Color Recapture and Dynamic Filtering: A Method of Scrolling Color

Increased contrast ratios are essential to the continued success of DLP products in the marketplace, from rear-projection televisions and home-theatre systems to large venue displays and DLP Cinema. The contrast of DLP projection systems has increased steadily over the past 5 years due to improvements in illumination and projection optics, as well as changes to the DMD itself. The authors will present an overview of the contrast performance of DLP projectors over time as well as describe illumination and projection techniques that optimize the performance of the DMD.

D. Scott Dewald

Papers

Illumination system for scrolling color recycling

Color correction filter for displays

High contrast projection

40.2: Sequential Color Recapture and Dynamic Filtering: A Method of Scrolling Color

Advances in contrast enhancement for DLP projection displays