Patent ID: 6188460
Filing Date: 2001-02-13
Classification: B82Y,E06B,F24S,G01D,G02B,G02F,G03B,G06F,H04N,Y02E

Abstract:
An image display panel employing the recycling of light from a plurality of light reflective elements therewithin so as to produce color images with enhanced brightness, said image display panel comprising:a backlighting structure includinga light source for producing light consisting of spectral components having wavelengths over a substantial portion of the visible band of said electromagnetic spectrum, anda broad-band reflector for reflecting, within said backlighting structure, polarized light consisting of spectral components having wavelengths over a substantial portion of said visible band and, upon one or more reflections within said backlighting structure, converting the polarization state of said spectral components from a first polarization state (P1) to a second polarization state (P2) orthogonal to said first polarization state (P1), and from said second polarization state (P2) to said first polarization state (P1);a plurality of pixel regions spatially encompassed within a predefined image display area definable relative to said backlighting structure, wherein each said pixel region spatially encompasses a plurality of subpixel regions and each said subpixel region within each said spatially-encompassing pixel region has a predefined spectral band over the visible band of the electromagnetic spectrum;a broad-band reflective polarizer for reflecting light consisting substantially of spectral components having wavelengths over a substantial portion of said visible band and said first polarization state (P1), and transmitting a distribution of polarized light along a prespecified direction, substantially confined within said predefined image display area, and consisting substantially of spectral components having wavelengths over a substantial portion of said visible band and said second polarization state (P2);a spatial intensity modulation structure includingan array of polarization modifying elements, each said polarization modifying element being spatially registered with one said subpixel region and selectively modifying the polarization state of polarized light transmitted therethrough in response to a subpixel drive signal provided to said polarization modifying element, anda broad-band polarizer, cooperating with said array of polarization modifying elements, so as to modulate the spatial intensity of said produced distribution of polarized light and thereby produce a dark-type or bright-type intensity level at each said subpixel region along said broad-band polarizer; anda spectral filtering structure having a pixelated array of pass-band reflective-type spectral filtering elements realized within a single layer of optical material, for spectrally filtering said polarized light, each said pass-band reflective-type spectral filtering element being spatially registered with one said subpixel region and tuned to one said predefined spectral band for transmitting only the spectral components of said polarized light having wavelengths within said predefined spectral band of said subpixel region, and reflecting the spectral components of said produced polarized light having wavelengths outside said predefined spectral band of said subpixel region so as to produce a predefined color value at said subpixel region spatially-registered with said pass-band reflective-type spectral filtering element;wherein, the spectral components of polarized light that are transmitted through said broad-band reflective polarizer along said prespecified direction contribute to said distribution of polarized light;wherein, the spectral components of polarized light that are not transmitted through said broad-band reflective polarizer along said prespecified direction are reflected off said broad-band reflective polarizer and transmitted back towards said broad-band reflector for reflection and/or polarization conversion within said backlighting structure and retransmission through said broad-band reflective polarizer so as to contribute to said distribution of polarized light;wherein, the spectral components of said polarized light that are transmitted through the pass-band reflective-type spectral filtering element at each said subpixel region within each said spatially-encompassing pixel region produce said predefined color value at said subpixel region; andwherein, the spectral components of said polarized light that are not transmitted through the pass-band reflective-type spectral filtering element at each said subpixel region within each said spatially-encompassing pixel region are reflected off said pass-band reflective-type spectral filtering element and transmitted back towards said backlighting structure for reflection and/or polarization conversion and retransmission towards the other said subpixel regions within said spatially-encompassing pixel region in said spectral filtering structure;whereby said color images are produced from said predefined image display area having enhanced brightness.