Patents Examined by Magda Crud
  • Patent number: 7665850
    Abstract: Prism elements having TIR surfaces placed in close proximity to the active area of a SLM device to separate unwanted off-state and/or flat-state light from the projection ON-light bundle. The TIR critical angle of these prisms is selected to affect either the off-state light or additionally, any portion of flat-state light reflected from the SLM. These TIR surfaces are placed to immediately reflect the unwanted light as it comes off the SLM, thereby preventing the contamination of light along the projection path, which tends to degrade the system contrast. To further improve the optical performance of the system, these TIR prisms can be attached directly to the SLM package, completely eliminating the package window. Also, these TIR prism can be coupled to DMDs having asymmetric mirrors, which tilt through a larger angle for the ON-light to provide high etendue and lumen output, but through near-zero degrees for the OFF-light, thereby improving the separation of any unwanted light from the off/flat states.
    Type: Grant
    Filed: April 24, 2007
    Date of Patent: February 23, 2010
    Assignee: Texas Instruments Incorporated
    Inventor: Steven M. Penn