Metal/Dielectric Color Filters for Flat Panel Displays

A report expands on the proposal described in “Low-Absorption Color Filters for Flat Panel Display Devices” (NPO-20435) NASA Tech Briefs, Vol. 23, No. 12 (December 1999), page 34. To recapitulate: The dye pixel color filters in a conventional liquid-crystal or other display device would be replaced with interference filters, which are less absorptive, and optics would be configured so that light reflected from the filters would be reused as illumination. The overall effect would be to increase brightness and efficiency. The present report adds specificity by proposing that the interference filters be of the type described in “Metal/Dielectric-Film Interference Color Filters” (NPO-20217), NASA Tech Briefs, Vol. 23, No. 2 (February 1999), page 70: Each filter would be made of three thin metal films interspersed with two thin dielectric films. In comparison with conventional multilayer all-dielectric filters, the proposed filters would contain fewer layers, and therefore could be fabricated more easily and at lower cost.