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

D. Scott DewaldTexas Instruments, IncorporatedDigital Imaging Group6550 Chase Oaks Blvd.M/S 8477Plano, Texas 75023E-mail: sdewald@ti.comAbstract. This paper discusses the use of ZEMAX’s Image Analysisfeature to verify and predict the performance of Digital Light Process-ing™ (DLP) projection-lens designs. The main goals are to visualize theeffects of lateral color, axial color, and the remaining Seidel aberrationson the focus of small DLP pixels on the screen in actual use. In manycases there is a discrepancy between what the projector user woulddeﬁne as ‘‘good pixel focus’’ or ‘‘sharp focus’’ and metrics that woulddetermine focus quality or resolution for the lens designer. ZEMAX Im-age Analysis is a valuable tool for lens design and visualizing lens per-formance before a prototype lens is built. In addition, the user-deﬁnedoffset surface is discussed, which was developed to simulate the sepa-rate focus of red, green, and blue DMDs™ in three-chip displays. Thisfeature is used to simulate the effect of interchangeable lenses, as eachlens has a different axial color characteristic and the depth of ﬁeld issmall, or to verify the compatibility of a lens design on a projector prefo-cused using a different lens. As display pixel sizes shrink, this simulationtechnique becomes more useful for evaluating projection lens designs,manufacturing tolerances, and ergonomic concerns during assembly.

Using ZEMAX Image Analysis and user-defined surfaces for projection lens design and evaluation for Digital Light Processing™ projection systems

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 contrast performance of DLP projectors over time as well as describe illumination and projection techniques that optimize the performance of the DMD.

46.1: Invited Paper: Advances in Contrast Enhancement for DLP Projection Displays

A projection lens ( 400 ) having a BFD:EFL, ratio in the range of 0.80:1 to 1.60:1, an air equivalent BFD of at least 4.3 inches, a throw ratio in the range of 3:1 to 6:1, and lateral color correction of one-quarter pixel when used with an SXGA modulator having pixels on 0.17 μm centers, and operating with its chief rays telecentric at the plane of the modulator. The projection lens comprises an objective lens group ( 402 ), a telecentric lens group ( 404 ), and an aperture stop ( 414 ) between the objective lens group and the telecentric lens group.

Telecentric projection lens

An optical system and method of increasing the contrast of a projected image. The optical system ( 1800 ) comprises a combination of aperture stops ( 1810, 1812 ) in at least one of the illumination and projection paths to filter scattered light and/or light prone to scatter into the projection aperture.

D. Scott Dewald

Papers

Using ZEMAX Image Analysis and user-defined surfaces for projection lens design and evaluation for Digital Light Processing™ projection systems

46.1: Invited Paper: Advances in Contrast Enhancement for DLP Projection Displays

Telecentric projection lens

Illumination aperture for projection display