D. Scott Dewald

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

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.

Advances in contrast enhancement for DLP projection displays

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.

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

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.

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

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.