Optical loss structure integrated in an illumination apparatus

Abstract

Various embodiments of a display device described herein include an optical propagation region, at least one optical loss structure, an optical isolation layer, and a plurality of display elements. The propagation region includes a light guide in which light is guided via total internal reflection and turning features configured to redirect the light out of the propagation region. The loss structure would disrupt the total internal reflection of at least some of the light guided within the propagation region if disposed directly adjacent thereto. The optical isolation layer includes a non-gaseous material between the propagation region and the loss structure, and is configured to increase an amount of light that is totally internal reflected in the propagation region. The plurality of display elements are positioned to receive the light redirected out of the propagation region. The loss structure is positioned between the plurality of display elements and the propagation region.

1 . (canceled) 
     
     
         2 . A display device comprising:
 a plurality of display elements;   an optical propagation region including:
 a substrate to provide support to the plurality of display elements, wherein the substrate is configured to guide light in the optical propagation region via total internal reflection; and 
 turning features configured to redirect the light out of the optical propagation region, wherein the plurality of display elements are positioned to receive the light redirected out of the optical propagation region; 
   at least one optical loss structure between the plurality of display elements and the optical propagation region, wherein the at least one optical loss structure would disrupt the total internal reflection of at least some of the light guided within the optical propagation region if disposed directly adjacent to the optical propagation region; and   an optical isolation layer between the optical propagation region and the at least one optical loss structure, the optical isolation layer including a non-gaseous material adjacent to the optical propagation region, the optical isolation layer configured to cause total internal reflection of the light guided in the optical propagation region.   
     
     
         3 . The display device of  claim 2 , wherein the plurality of display elements are reflective display elements configured to reflect light to produce an image. 
     
     
         4 . The display device of  claim 3 , configured such that the light reflected by the plurality of display elements to produce the image passes through the optical loss structure, the optical isolation layer, and the optical propagation region. 
     
     
         5 . The display device of  claim 3 , wherein the plurality of reflective display elements includes a plurality of interferometric modulators. 
     
     
         6 . The display device of  claim 2 , wherein the at least one optical loss structure includes a diffuser. 
     
     
         7 . The display device of  claim 6 , wherein the diffuser includes surface diffusing features. 
     
     
         8 . The display device of  claim 7 , wherein the optical isolation layer is adjacent to the at least one optical loss structure such that an interface between the optical isolation layer and the at least one optical loss structure includes the surface diffusing features. 
     
     
         9 . The display device of  claim 6 , wherein the diffuser includes a plurality of microstructures disposed in a matrix material. 
     
     
         10 . The display device of  claim 2 , wherein the optical isolation layer includes a multi-layer interference stack. 
     
     
         11 . The display device of  claim 10 , wherein the multi-layer interference stack includes:
 a first layer closest to the optical propagation region, the first layer having an index of refraction higher than an index of refraction of the optical propagation region, wherein the first layer is a sub-wavelength thin film having a thickness less than about a wavelength of visible light; and   a second layer having an index of refraction lower than the index of refraction of the optical propagation region such that the second layer causes light to be guided via total internal reflection in the optical propagation region and the first layer.   
     
     
         12 . The display device of  claim 11 , wherein the multi-layer interference stack includes a third layer having an index of refraction that is higher than the index of refraction of the second layer of the multi-layer interference stack, and wherein the second layer is between the first layer and the third layer. 
     
     
         13 . The display device of  claim 12 , wherein the first and third layers include titanium dioxide and the second layer includes magnesium fluoride. 
     
     
         14 . The display device of  claim 10 , wherein the multi-layer interference stack includes a plurality of layers each having a thickness less than about a wavelength of visible light. 
     
     
         15 . The display device of  claim 10 , wherein the multi-layer interference stack includes a plurality of optical films having indices of refraction that alternate between higher than the index of refraction of the optical propagation region and lower than the index of refraction of the optical propagation region. 
     
     
         16 . The display device of  claim 2 , wherein the plurality of display elements are adjacent to the at least one optical loss structure. 
     
     
         17 . The display device of  claim 2 , wherein the optical propagation region includes a light guide, wherein the light guide and the substrate are configured to guide the light in the optical propagation region via total internal reflection, and wherein the light guide includes the turning features. 
     
     
         18 . The display device of  claim 2 , further comprising:
 a processor that is configured to communicate with the plurality of display elements, the processor being configured to process image data; and   a memory device that is configured to communicate with the processor.   
     
     
         19 . The display device of  claim 18 , further comprising:
 a driver circuit configured to send at least one signal to the plurality of display elements; and   a controller configured to send at least a portion of the image data to the driver circuit.   
     
     
         20 . The display device of  claim 18 , further comprising an image source module configured to send said image data to said processor, wherein the image source module includes at least one of a receiver, transceiver, and transmitter. 
     
     
         21 . The display device of  claim 18 , further comprising an input device configured to receive input data and to communicate said input data to said processor. 
     
     
         22 . A method of making a display device, the method comprising:
 providing an optical propagation region that includes:
 a substrate that is configured to guide light in the optical propagation region via total internal reflection; and 
 turning features configured to redirect the light out of the optical propagation region; 
   disposing a plurality of display element to receive the light redirected out of the optical propagation region, wherein the substrate of the optical propagation region provides support to the plurality of display elements;   disposing at least one optical loss structure between the plurality of display elements and the optical propagation region, wherein the at least one optical loss structure would disrupt the total internal reflection of at least some of the light guided within the optical propagation region if disposed directly adjacent to the optical propagation region; and   disposing an optical isolation layer between the optical propagation region and the at least one optical loss structure, the optical isolation layer including a non-gaseous material adjacent to the optical propagation region, the optical isolation layer configured to cause total internal reflection of the light guided in the optical propagation region.   
     
     
         23 . The method of  claim 22 , wherein the substrate includes a first side and a second side, wherein the optical isolation layer is deposited onto the first side of the substrate, wherein the at least one optical loss structure is deposited onto the optical isolation layer, and wherein the plurality of display elements are deposited onto the at least one optical loss structure. 
     
     
         24 . The method of  claim 23 , wherein the optical propagation region includes a light guide disposed on the second side of the substrate, wherein the substrate and the light guide are configured to guide the light in the optical propagation region via total internal reflection, and wherein the light guide includes the turning features. 
     
     
         25 . The method of  claim 22 , wherein the plurality of display elements are reflective display elements configured to reflect light to produce an image. 
     
     
         26 . The method of  claim 22 , wherein the at least one optical loss structure includes a diffuser. 
     
     
         27 . The method of  claim 26 , wherein the diffuser includes surface diffusing features. 
     
     
         28 . The method of  claim 26 , wherein the diffuser includes a plurality of microstructures disposed in a matrix material. 
     
     
         29 . The method of  claim 22 , wherein the optical isolation layer includes a multi-layer interference stack. 
     
     
         30 . A display device comprising:
 a plurality of display elements;   an optical propagation region including:
 means for supporting the plurality of display elements, wherein the supporting means is configured to guide light in the optical propagation region via total internal reflection; and 
 means for redirecting light out of the optical propagation region, wherein the plurality of display elements are positioned to receive the light redirected out of the optical propagation region; 
   means for disrupting the total internal reflection of at least some of the light guided within the optical propagation region if disposed directly adjacent to the optical propagation region, wherein the disrupting means is between the optical propagation region and the plurality of display elements; and   means for optically isolating the optical propagation region from the disrupting means, wherein the optically isolating means is between the optical propagation region and the disrupting means, the optically isolating means including a non-gaseous material adjacent to the optical propagation region, the optically isolating means configured to cause total internal reflection of the light guided in the optical propagation region.   
     
     
         31 . The display device of  claim 30 , wherein the supporting means includes a substrate, or wherein the light redirecting means includes turning features, or wherein the disrupting means includes at least one loss structure, or wherein the optically isolating means includes an optical isolation layer.