Patent Publication Number: US-7595934-B2

Title: Integrated sub-assembly having a light collimating or transflecting device

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application is a continuation-in-part of U.S. application Ser. No. 11/194,360 filed on Aug. 1, 2005. U.S. application Ser. No. 11/194,360 is, in turn, a continuation-in-part of U.S. application Ser. No. 10/108,296 filed on Mar. 26, 2002, a continuation-in-part of U.S. application Ser. No. 10/688,785 filed on Oct. 17, 2003, and also claims the benefit of priority of U.S. Provisional Application No. 60/600,272 filed on Aug. 10, 2004. 

   FIELD OF INVENTION 
   The present application relates to integrated sub-assemblies having transflective structures and/or light collimating structures. In particular, the present application relates to integrated sub-assemblies with no air gaps or air layers between films or other elements. 
   BACKGROUND 
   Light collimating films, sometimes known as light control films, are known in the art. Such films typically have opaque plastic louvers lying between strips of clear plastic. U.S. Pat. No. Re 27,617 teaches a process of making such a louvered light collimating film by skiving a billet of alternating layers of plastic having relatively low and relatively high optical densities. After skiving, the high optical density layers provide light collimating louver elements which, as illustrated in the patent, may extend orthogonally to the surface of the resulting louvered plastic film. U.S. Pat. No. 3,707,416 discloses a process whereby the louver elements may be canted with respect to the surface of the light collimating film. U.S. Pat. No. 3,919,559 teaches a process for attaining a gradual change in the angle of cant of successive louver elements. 
   Such light collimating films have many uses. U.S. Pat. No. 3,791,722 teaches the use of such films in lenses for goggles to be worn where high levels of illumination or glare are encountered. Such films also may be used to cover a backlit instrument panel, such as the dashboard of a car, to prevent undesired reflections in locations such as the windshield, or a backlit electronic device (e.g., a LCD computer screen or LCD TV). 
   U.S. Pat. No. 5,204,160 discloses light collimating films that are formed from a plastic film with a series of grooves formed therein. The grooves are filled with a light absorbing material or the sides and bottoms of the grooves may be painted with a light absorbing ink. 
   In known collimating films, light management is controlled by an external air boundary. In other words an air layer is required between the output of the collimating film and any other optical films to allow the films to function together. A typical embodiment consists of an assembly where at least some elements of optical film are separated by a layer of air. The optical films are considered separated by a layer of air when the films are not optically coupled or joined by a non-gaseous medium (i.e., a medium other than air). The air layer provides a difference in index of refraction relative to the element which enables the element to perform. However, this air layer between films caused light loss and precludes the use of integrated sub-assemblies. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the accompanying drawings, structures are illustrated that, together with the detailed description provided below, describe exemplary embodiments of the claimed invention. In the drawings and description that follows, like elements are identified with the same reference numerals. The drawings are not to scale and the proportion of certain elements may be exaggerated for the purpose of illustration. 
       FIG. 1A  is a three-dimensional depiction of one embodiment of an optical element; 
       FIG. 1B  is a depiction of a vertical plane cross-section of one embodiment of an optical element; 
       FIGS. 2A ,  2 B, and  2 C are three-dimensional depictions of additional embodiments of optical elements; 
       FIG. 3  is a depiction of a vertical plane cross-section of one embodiment of an optical element; 
       FIG. 4  is a three-dimensional depiction of one embodiment of an optical element array; 
       FIGS. 5A ,  5 B, and  5 C illustrate one embodiment of a light collimating or funneling device; 
       FIG. 6  is another embodiment of a light collimating or funneling device; 
       FIGS. 7A and 7B  illustrate another embodiment of a light collimating or funneling device; 
       FIG. 8  is one embodiment of a transflective device; 
       FIG. 9  is one embodiment of a transflector having both a light collimating or funneling device and transflective device; 
       FIGS. 10A and 10B  are embodiments of a system having transflective pixels and an optical element layer; 
       FIGS. 11A and 11B  are embodiments of a system having transflective pixels, a light collimating device, and an optical element layer; 
       FIG. 12  is a three-dimensional depiction of one embodiment of a light collimating or funneling structure having two layers; 
       FIG. 13  is a plan view of one embodiment of an integrated sub-assembly having a collimating device and having no air layers between elements; 
       FIG. 14  is a plan view of one embodiment of an integrated sub-assembly having a collimating device and having a low index of refraction polymer between elements; 
       FIG. 15  is a plan view of one embodiment of an integrated sub-assembly having a transflecting device and having no air layers between elements; 
       FIG. 16  is a plan view of one embodiment of an integrated sub-assembly having a transflecting device and having a low index of refraction polymer between elements; 
       FIG. 17  is a plan view of one embodiment of an integrated sub-assembly having both a collimating device and a transflecting device and having no air layers between elements; 
       FIG. 18  is a plan view of one embodiment of an integrated sub-assembly having both a collimating device and a transflecting device and having a low index of refraction polymer between elements; 
       FIG. 19  is a front plan view of a prior art sub-assembly having a prior art collimating device with an external air boundary and a second optical element; 
       FIG. 20A  is a perspective view of a prior art sub-assembly having a prior art collimating device that includes a first collimator and a second collimator, and a second optical element; 
       FIG. 20B  is a front plan view of the prior art sub-assembly of  FIG. 20A ; 
       FIG. 21  is a front plan view of one embodiment of a sub-assembly having a prior art collimating device and a second optical element, separated by a material layer; 
       FIG. 22  is a front plan view of one embodiment of a sub-assembly having a prior art collimating device that includes a first collimator and a second collimator, and a second optical element, each separated by a material layer. 
   

   DETAILED DESCRIPTION 
   The following includes definitions of selected terms employed herein. The definitions include various examples and/or forms of components that fall within the scope of a term and that may be used for implementation. The examples are not intended to be limiting. Both singular and plural forms of terms may be within the definitions. 
   An “air layer” as used herein, refers to a separation between elements that is a vacuum or filled with air or other gas, through which light travels during operation of a device, affecting the path of the light. Microscopic air gaps that do not affect the path of the light do not constitute air layers. 
   A “horizontal plane cross-section” as used herein, refers to a cross-section taken along a plane perpendicular to the direction of the element. 
   “Tapered” as used herein, refers to a narrowing along either a linear or curved line in the vertical plane cross-section direction, such that horizontal plane cross-sections taken at different locations will have different areas. In other words, a tapered object will have a small area end and a large area end. 
   A “vertical plane cross-section” as used herein, refers to a cross-section taken along a plane parallel to the direction of the element. 
   The present application relates to both (1) transflective structures and (2) light collimating or funneling structures. Funneling is essentially the action of a funnel. A funnel is typically defined as a conically shaped pipe, employed as a device to channel liquid or fine-grained substances into containers with a small opening. Funnel in this application refers to a general shape only, wherein there is a small end and a large end, with the entire structure not necessarily conical. The funneling of light in the transflective application is essentially from the large end to the small end. The funneling of light in the collimating application is essentially from the small end to the large end. 
   Light collimation is defined as taking a given angular distribution of a light source and increasing the peak intensity by the process of narrowing the given angular distribution. 
   Light collimating or funneling effects can be accomplished by using an optical layer formed by a series of discrete tapered optical elements in combination with an immersing layer and a reflecting layer having openings or apertures disposed therein, corresponding to the positioning and shape of the tapered ends of the optical elements. To perform a light collimating or funneling function, the optical element is tapered towards a light source, such that the optical element has a large area end and a small area end. In this manner, the small area ends are light input ends and the large area ends are light output ends. 
     FIG. 1A  illustrates one embodiment of an optical element  10  having a light input end  12 , a light output end  14 , and at least one sidewall  16 . In this embodiment, the sidewall  16  is constrained like a Compound Parabolic Concentrator (CPC). In other words, the vertical plane cross-section of optical element  10  is parabolic or approximately parabolic. In the illustrated embodiment the optical element  10  has a circular horizontal plane cross-section. In other embodiments (not shown), the horizontal plane cross-section is square or rectangular. 
     FIG. 1B  illustrates a depiction of a vertical plane cross-section of the same optical element  10 . As illustrated, light L enters the optical element  10  at the light input end  12  from multiple directions. As the light L travels through the optical element  10 , it impinges on a CPC or parabolic-like sidewall  16 . The CPC or parabolic-like sidewall reflects the light L and focuses it an angle such that the light L emerges from the light output end  14  as a substantially uniform sheet. 
     FIG. 2A  illustrates another embodiment of an optical element  20  having a light input end  21 , a light output end  22 , and a square horizontal plane cross-section. As will be shown in detail below, a square cross-section allows for a higher packing density of optical elements in an optical element array. In alternative embodiments (not shown), the optical element may have a rectangular or any regular polygonal shaped horizontal cross-section that may be regular. In general, regular polygonal cross-sections allow for a higher packing density than circular cross-sections. 
   With continued reference to  FIG. 2A , a CPC structure  23  is located at the light input end  21  and a linear section  24  is located at the light output end  22  of the optical element  20 . In another embodiment (not shown), a CPC section similar to that shown in  FIG. 1  replaces the combination of the CPC structure  23  and the linear section  24  shown in  FIG. 2A . 
     FIG. 2B  illustrates an embodiment of an optical element  20  having a light input end  21 , a light output end  22 , and a square cross-section. In this embodiment, the optical element  20  includes a curved section  25  at the light input end, wherein the curved section  25  is defined by an arc of a circle so as to approximate a CPC. The optical element  20  further includes a linear section  24  located at the light output end  22 . In this embodiment, a CPC structure is approximated by matching the slope of the curved section  25  with the slope of the linear section  24  at the intersection point of the curved and linear sections  24 ,  25 . 
     FIG. 2C  illustrates another embodiment of an optical element  20  having a square light input end  21  and a square light output end  22 . In this embodiment, a first linear section  24  is located at the light output end  22  and a second linear section  26  is located at the light input end  21 . A CPC structure  23  is located between the first and second linear sections  24 ,  26 . In an alternative embodiment (not shown), the CPC structure  23  is replaced with a circular approximation of a CPC structure. In either embodiment, a minimum draft angle θ is required for manufacturability. The draft angle is defined as the complement of the angle formed between the light output area  22  and the plane of the linear section  24 . In one embodiment, the draft angle is selected such that there is continuity and a continuous slope between sections  23  and  24  and between sections  23  and  26 . 
     FIG. 3  illustrates a side view, the equivalent of a vertical plane cross section, of one embodiment of an optical element  30  having a square light input end  32  and a square light output end  34 . In this embodiment, there are no linear sections. Instead, the sidewall  36  of the optical element  30  are circular approximations of a CPC structure. 
   In other embodiments (not shown), the optical elements have any suitable tapered shape including, without limitation, pyramids, cones, or any other three-dimensional polygon or polyhedron. Further, the discrete faces of the optical elements can be planar, concave, convex, or pitted such that light entering the interior of an optical element is controlled, funneled or collimated. 
   In other embodiments (not shown), the optical elements have intersecting indentations, non-intersecting indentations, cones, conic sections, three-dimensional parabolic structures, pyramids, polygons, polyhedrons (e.g., tetrahedrons), regular multi-sided structures, or irregular multi-sided structures. The reflectance, transmittance, and absorption of the optical elements may have different values. The sides of the structures may be linear, non-linear, or a combination thereof. 
   An approximation of a CPC shape is easier to manufacture than a true CPC shape, and maintains, or in some cases even improves, peak performance. An arc of a circle is an example of an approximation of a CPC that may improve performance. A CPC structure may be approximated by an arc of a circle or a combination of a linear region on each side of a CPC section. Alternatively, a CPC structure can be approximated by one linear region adjacent a CPC section. In one embodiment, the horizontal plane cross-section can be square or rectangular, creating orthogonal lenticular channels. Creating at least two non-orthogonal lenticular channels can produce other cross sections for the collimating structure. The cross sections can also be any regular or irregular polygon. 
   A rectangular shaped horizontal plane cross-section (with a corresponding rectangular shaped input end) may result in a collimated light output that is not symmetric. The angular distribution of light output along the length of the rectangular input structure is greater than the angular distribution of light along its width. Increasing the length of the rectangular input structure increases the input area relative to the output area of the element, thus more total energy is available at the output of the element. Therefore, the angular distribution of the output light can be pre-determined based on the display application. The area of the input relative to the output is a design parameter of the device that allows control of the angular distribution of the output light. This can be applied, for example, in a liquid crystal display television (LCD-TV) in which the horizontal direction requires a wider viewing angle than the vertical direction. To satisfy the requirement for a wider viewing angle, the length of the input structure would run in the horizontal direction while the width would run vertically. 
   In one embodiment, the draft angle may be about 8° or more, thereby yielding a device whose performance may be the same as if the second linear section was extended to define the entire device. In other words, the performance may be as if the first linear section and CPC were removed and replaced by an extension of the second linear section. Such a design would be chosen for ease of manufacturing, although performance is lowered. Smaller draft angles have higher performance, but are more difficult to manufacture because of higher aspect ratio. The aspect ratio is defined as the ratio of the depth of the light-guide to the distance between input apertures. A CPC (or circular fit to a CPC) device allows for the design of a low aspect ratio easy to manufacture device rather than the same performing higher aspect linear device. For example, a linear design with a draft angle of 3.5° (or aspect ratio of close to 8:1) would have about the same performance as a CPC (or circular equivalent) device of aspect ratio about 2.9:1. In other embodiments, the CPC approximation has an aspect ratio range of less than 1:1 to greater than about 7.5:1. 
     FIG. 4  illustrates one embodiment of an optical element array (also referred to as an optical element layer). The optical element array here is a 10×10 element array (100 total elements). However, in other embodiments, an optical element array can be of any desired size or include any desired number or arrangement of optical elements. 
   In alternative embodiments (not shown), the optical elements are arranged in a variety of patterns. For example, the optical elements may be repeated in parallel and spaced across the area of the film. The optical elements may be arranged in varying shapes, heights, angles, or spacings before a pattern is repeated. Alternatively, the optical elements may be arranged randomly so that there is no discernable pattern. Occasional variation in structure, or what might be termed disruptive structures, may be used to eliminate or reduce effects of unwanted aberrations (such as Moiré effects). 
   In one embodiment, the optical element array is formed from a highly transmissive polymer with an index of refraction exceeding that of air (i.e., an index of refraction greater than 1). In one embodiment, the index of refraction for the polymer forming the light containing region of the optical element is at least about 1.1, or even at least about 1.2. In another embodiment, the index of refraction for the polymer used to form the light containing region of the optical element is in the range of about 1.3 to about 1.8. This region is surrounded by any compatible material—for example, air or a polymer of lower index of refraction than the light containing region—that allows total internal reflection (TIR) at the internal boundary (the boundary internal to the device) of the light containing region. The lower the index of refraction of the polymer of the light containing region of the optical element, the smaller the Fresnel losses at the external air boundary of the input and output ends. This process of improved gain with lower index of refraction is limited only by the requirement to find a compatible material of low enough index of refraction to allow TIR at the internal boundary. 
     FIGS. 5A ,  5 B, and  5 C show exploded, assembled, and side (the equivalent of a vertical plane cross section) views, respectively, of a light collimating or funneling structure  100 . Also shown in  FIGS. 5A ,  5 B, and  5 C is a backlight  110  (such as one that is used in a LCD TV) having a surface  120  that simultaneously acts as an emitting and reflecting surface. Anyone familiar with the state of the art will recognize that this is a standard feature in LCD backlights. The reflecting feature allows for light recycling, a property that is necessary for performance. The collimating or funneling structure  100  includes an immersing layer  130  with a reflecting layer  140  formed thereon and an optical element layer  150 . 
   In one embodiment, the immersing layer  130  is constructed of a polymeric material. Minimizing Fresnel losses requires an optically transparent material of the same index of refraction as the light containing region of the device. In another embodiment, any optically transparent material of any index of refraction can be used, including glass or air. If air is used, the reflecting layer  140  is deposited directly on the optical element layer  150 . 
   The reflecting layer  140  includes apertures (or openings)  160  which match light input ends  170  of optical elements in the optical element layer  150 . In one embodiment, the reflecting layer  140  is created by sputtering or chemically vapor depositing (CVD) a thin film of several microns of highly reflecting material onto a highly transmissive polymer substrate (the immersing layer  130 ) and selectively removing reflecting material at the location of the light input ends  170 . The apertures  160  in the reflecting layer  140  can also be created by extending the material of the light input ends  170  and piercing through the reflecting layer  140 . In one embodiment, the input apertures are in the same plane as the top of the reflecting layer. In one embodiment, the reflecting layer  140  is constructed of metal, such as nickel, gold, aluminum, silver, or other suitable metal. However, in other embodiments (not shown), the reflecting layer may be constructed of any reflecting substance. 
   The highly transmissive polymer substrate used to construct the immersing layer  130  may be the same polymer used in the optical elements in the optical element layer  150 . The use of the same polymer would allow an optically seamless interface with the rest of the collimating or funneling structure and minimize Fresnel losses. In the case where the reflecting layer  140  acts as a specular or diffuse scattering layer, the reflecting layer  140  has as high a reflectivity as possible, with specular or diffuse reflection in the one embodiment in excess of 95%. The excess reflective material, the reflective material that would block the input to the light-containing region of the device, may be removed by, for example, masking and etching, so that the areas without reflecting material form the apertures  160 . As noted above, the reflecting layer  140 , with apertures  160  formed therein, can be located on either side of the immersing layer  130 , so long as there is at least one reflecting layer  140  facing the backlight  110 . 
   Here, the reflecting layer  140  acts as a thin, specularly reflecting layer that allows the light from the source to be recycled by reflection. In an alternative embodiment, the reflecting layer  140  is a diffuse reflecting layer rather than a specular reflecting layer. However, the preferred embodiment is for a specularly reflecting layer  140  because ray-tracing calculations show a decline in performance of a diffuse reflecting layer, relative to a specularly reflecting layer. In another alternative embodiment, the surface of the reflecting layer  140  is textured (with, for example, systematic or random depressions or elevations, such as dimples) to guide the light into the input apertures more efficiently, that is with a minimum number of reflections and minimum energy lost. The reflective surface of the LCD backlight reflector can also be optically tuned to match the reflective layer of the device with the same goal of minimizing the number of reflections while guiding the light into the input apertures. 
   With continued reference to  FIGS. 5A ,  5 B, and  5 C, the reflecting layer  140  is disposed on the side of immersing layer  130  opposite from the backlight  110 . In an alternative embodiment (not shown), the reflecting layer  140  is disposed on the side of the immersing layer  130  that faces the backlight  110 . In either embodiment, the reflecting layer  140  reflects light towards the backlight  110  for recycling. 
   In the illustrated embodiments, the immersing layer  130  is in direct contact with the backlight  110 . In other words, no air layer exists between the backlight  110  and the immersing layer  130 . In one embodiment, the immersing layer  130  is optically coupled to the backlight  110 . In an alternative embodiment, the immersing layer  130  is a pressure sensitive adhesive, structural adhesive, or other known bonding material that is applied to the backlight  110 . In another alternative embodiment, the collimating structure  100  is a film that is laminated directly to the backlight  110 . In yet another alternative embodiment (not shown), a first side of a pressure sensitive adhesive, structural adhesive, or other known bonding material is applied to the immersing layer  130  and a second side of the pressure sensitive adhesive, structural adhesive, or bonding material is applied to the backlight  110 . 
   In this embodiment, the collimating or funneling structure  100  includes an optical element layer  150  formed from a plurality of three-dimensional optical elements having a light input end  170  and a light output end  180 . In the embodiment illustrated in  FIGS. 5A ,  5 B, and  5 C, the optical elements are joined together to form a sheet at the light output ends  180 , thereby yielding a continuous collimating film. In an alternative embodiment, shown in  FIG. 6 , the light containing region of the optical elements are discrete and detached from each other, but are joined in a common polymer sheet  185 . 
   In the embodiment illustrated in  FIGS. 5A ,  5 B, and  5 C, the light input side  170  of the optical element layer  150  is in contact with the reflecting layer  140 , such that the optical elements of optical element layer  150  correspond to the apertures  160  formed in the reflecting layer  140 . In an alternative embodiment, shown in  FIG. 6 , the optical elements of the optical element layer  150  extend to embed the reflecting layer  140 . In other words, the light input ends  170  extend into the apertures  160  of the reflecting layer  140  and contact the immersing layer  130 . In this embodiment, there is no gap between the immersing layer  130  and the optical element layer  150 . This may be achieved by manufacturing the immersing layer  130  and the optical element layer  150  as a single continuous layer, and later joining (for example, laminating) the reflecting layer  140  onto the optical element layer  150 . In  FIG. 6 , as in  FIGS. 5B and 5C , no air layer exists between the backlight  110  and the immersing layer  130 . 
   In another alternative embodiment (not shown), the reflecting layer  140  is formed on the side of the immersing layer  130  facing the backlight, and the light input side  170  of the optical elements is in contact with the immersing layer  130 . 
   Regardless of the positioning of the reflecting layer  140  in relation to the immersing layer  130 , the reflecting layer  140  faces the backlight  110 . The light emitted from the backlight  110  must eventually pass through the aperture  160  in the reflecting layer  140  and through the optical elements of the optical element layer  150  in order to be collimated. Light not passing through an aperture  160  is reflected back to the backlight  110 , which subsequently reflects the light back towards apertures. The light is then repeatedly reflected until it either passes through an aperture  160 , or is lost to the system by absorption. The exit angular distribution of the collimated light may be designed so as to match the range of pixel acceptance angles found in different LCD display types. This would maximize the amount of light incident on the pixel that could be processed by the LCD, thereby maximizing the luminance perceived by an observer. 
   In one type of transflective LCD, additional light recycling can occur between the structure  100  and light reflected from the backside of a reflective portion of a pixel and recycled. This type of transflective LCD is constructed of pixels containing both a transmissive aperture and a reflective region. In another type of transflective LCD, the pixel is transmissive and the reflective region is located on an optical element exterior to the pixel. The major difference between such a transflective LCD and a transmissive LCD is the reflective region located on an optical element exterior to the pixel. The transmissive LCD could include the collimating device disclosed herein. 
     FIGS. 7A and 7B  illustrate another embodiment of a light collimating or funneling structure  100 , in which the air space between the optical elements of the optical element layer are filled with a fill material  190 . In one embodiment, the fill material  190  is constructed of a polymeric material having an index of refraction that is lower than the polymer used for the optical element layer  150 . The difference in indices of refraction of the polymers may be selected to maintain TIR (total internal reflection). The difference in index of refraction of the regions necessary to maintain TIR decreases as the index of refraction of the light-containing region increases. In one known embodiment, the index of refraction of the fill material  190  is lower than that of the optical element layer  150  by a factor of about 0.15. In an alternative embodiment, difference between the index of refraction of the fill material  190  and that of the optical element layer  150  can be lower than 0.15, but light leakage from the optical element layer  150  progressively lowers the performance as the index of refraction difference declines. 
   It should be noted that there is no upper limit on the difference between the indices of refraction between the polymer occupying/filling the air spaces and the polymer used to form the optical element layer  150 , so long as the minimum difference to create TIR without light leakage, as mentioned above, is met. 
   The transmissivity of the fill material  190  does not need to be high since no light passes through the material. In fact, since the transmissivity of the fill material  190  could be zero, metal could be used as a fill material  190 . The reflectivity of the metal must be sufficiently high to minimize energy loss (due to absorption or scattering by the metal) upon reflection of light from the boundary of the light-containing region. Since the surface between the input apertures of the light containing region must be covered by a reflecting material that allows for recycling of the light from the light source, using a polymer fill material  190  instead of air creates a surface for the reflecting material. A manufacturing method may allow for creating the reflecting surface  140  by deposition through a mask or by etching. A polymer immersing layer  110  may still be used to limit Fresnel losses. This embodiment is shown in  FIGS. 7A and 7B , with identical reference numerals used therein denoting identical portions of the light collimating or funneling structure  100  as discussed in relation to  FIGS. 5A ,  5 B, and  5 C. As such a discussion of the complete structure  100  disclosed in  FIGS. 7A and 7B  will be omitted for brevity. 
     FIG. 8  illustrates a transflective structure  200  according to another embodiment of the present application. The transflective structure  200  reflects light that arrives from a first direction (i.e. from an ambient light source A, such as the sun or a room light) and transmits light that arrives from an opposite direction (i.e. from a backlight  110 ). In this embodiment, the transflective structure  200  includes an immersing layer  230 , an optical element layer  250 , and a reflecting layer  240  that covers the surface of optical element layer  250  excluding only the output aperture  260 . The components of the transflective structure  200  are substantially the same as those used in the light collimating or funneling structure  100 , but they are reversed. 
   In the illustrated embodiment, the transflective structure  200  is positioned between a backlight  110  and an ambient light source A. The reflecting layer  240  is formed on the side of the immersing layer  230  that faces the optical element layer  250 . Alternatively, the reflecting layer  240  may be formed on the side of the immersing layer  230  that faces the ambient light source A or it may be formed on both sides of the immersing layer  230 . 
   With continued reference to  FIG. 8 , the optical element layer  250  is in direct contact with the backlight  110 . In other words, no air layer exists between the backlight  110  and the optical element layer  250 . In one embodiment, the optical element layer  250  is optically coupled to the backlight  110 . In another alternative embodiment, the transflective structure  200  is a film that is laminated directly to the backlight  110 . In yet another alternative embodiment (not shown), a first side of a pressure sensitive adhesive, or other known bonding material is applied to the optical element layer  250  and a second side of the pressure sensitive adhesive, structural adhesive, or other known bonding material is applied to the backlight  110 . 
   The structure and properties of the immersing layer  230  and the reflecting layer  240  are otherwise substantially similar to that of the immersing layer  130  and the reflecting layer  140  described above in relation to the light collimating or funneling structure  100 . As such, a discussion of the complete structure and properties of the immersing layer  230  and the reflecting layer  240  disclosed in  FIG. 8  will be omitted for brevity. 
   The optical element layer  250  may be formed of three dimensional tapered optical elements such as those shown in  FIGS. 1A ,  1 B,  2 A,  2 B,  2 C and  3 . In the illustrated embodiment, the small area ends of the optical elements face the ambient light source A, and thus function as light output ends for light transmitted from the backlight  110 . The light output ends of the optical elements of optical element layer  250  corresponds to the apertures  260  formed in the reflecting layer  240 . In this embodiment, the light output ends extend to contact the reflective layer  240 . In an alternative embodiment, the light output ends extend to embed the reflecting layer  240 , as shown in  FIG. 6 . In another alternative embodiment, the reflective layer  240  is formed on the side of the immersing layer  230  opposite the optical element layer  250  and the light output ends of the optical elements contact the immersing layer  230 . 
   The structure and properties of the optical element layer  250  are otherwise substantially similar to that of the optical element layer  150  described above in relation to  FIGS. 5-7 . As such, a discussion of the complete structure and properties of the optical element layer  250  disclosed in  FIG. 8  will be omitted for brevity. 
     FIG. 9  illustrates a transflector  900  having both a transflective structure  200  and a light collimating or funneling structure  100 . The transflector  900  reflects light that arrives from a first direction (i.e. from an ambient light source A, such as the sun or a room light) and transmits light that arrives from an opposite direction (i.e. from a backlight  110 ). In the illustrated embodiment, an immersing layer  130  is in direct contact with the backlight  110 , in one of the manners described in relation to  FIGS. 5B and 5C  above. 
   In the illustrated embodiment, a light collimating or funneling structure  100  is positioned between the backlight  110  and a transflective structure  200 , so that light emitted from the backlight  110  is first collimated or funneled by the light collimating or funneling structure  100  and is then transmitted through the transflective structure  200 . At the same time, ambient light is reflected off the reflecting layer  240 . 
   In an alternative embodiment (not shown), the transflective structure  200  is positioned between the backlight  110  and the light collimating or funneling structure  100 , so that light emitted from the backlight  110  is first transmitted through the transflective structure  200  and then is collimated or funneled by the light collimating or funneling structure  100  while ambient light is reflected off the reflecting layer  140 . The light collimating or funneling structure  100  and the transflective structure  200  are substantially the same as those discussed in relation to  FIGS. 5-7 . As such, a discussion of the complete light collimating or funneling structure  100  and transflective structure  200  disclosed in  FIG. 9  will be omitted for brevity. 
     FIG. 10A  illustrates a plan view of a display  1000   a  having transflective pixels  1010  and an optical element layer  250  of a transflector. In this embodiment, the transflective pixels  1010  have a reflective layer  1020 . The transflective pixels  1010  are aligned with the light output ends of the light containing regions of the optical element layer  250 . Because the pixels  1010  include a reflective layer  1020 , the optical element layer  250  has no need for a reflective layer. In this embodiment, the transflective pixels  1010  are located in a liquid crystal suspension  1030 . Color filters  1040  are also located in the liquid crystal suspension  1030 . The color filters  1040  are aligned with the transflective pixels  1010  and include red, green, and blue color filters. 
   With continued reference to  FIG. 10A , a backlight  110  is located adjacent a rear polarizer  1050 . The optical element layer  250  is positioned between the rear polarizer  1050  and the liquid crystal suspension  1030 . The liquid crystal suspension  1030  is also adjacent a front glass  1060 . The front glass is also adjacent a front polarizer  1070 . In an alternative embodiment (not shown), a diffuser is located immediately following the backlight  110  such that it is between the backlight  110  and the rear polarizer  1050 . In another alternative embodiment (not shown), a rear glass is disposed between the optical element layer  250  and the liquid crystal suspension  1030 . In yet another alternative embodiment (not shown), the optical element layer  250  is positioned behind the front polarizer  1070 . 
     FIG. 10B  illustrates an alternative embodiment of a display  1000   b  employing transflective pixels  1010  and an optical element layer  250  of a transflector. In this embodiment, the color filters  1040  are not located in the liquid crystal suspension  1030 . Instead, the color filters are disposed between a rear polarizer  1050  and a rear glass  1080 . The optical element layer  250  is located adjacent the backlight  110 , such that it is disposed between the backlight  110  and the rear polarizer  1050 . The rear glass  1080  is disposed between the color filters  1040  and the liquid crystal suspension  1030 . A front glass  1060  is disposed between a front polarizer  1070  and the liquid crystal suspension  1030 , as in  FIG. 10A . In an alternative embodiment (not shown), a diffuser is located immediately following the backlight  110  such that it is between the backlight  110  and the rear polarizer  1050 . 
     FIG. 11A  illustrates a display  1100   a  employing transflective pixels  1010 , a collimating device  100 , and an optical element layer  250  of a transflector. In this embodiment, the transflective pixels  1010  have a reflective layer  1020 . The transflective pixels  1010  are aligned with the light output ends of the light containing regions of the optical element layer  250 . Again, because the pixels  1010  include a reflective layer  1020 , the optical element layer  250  has no need for a reflective layer. The collimating device  100  includes an optical element layer  150  and a reflecting layer  140  having apertures  160 . In this embodiment, the transflective pixels  1010  are located in a liquid crystal suspension  1030 . Color filters  1040  are also located in the liquid crystal suspension  1030 . The color filters  1040  are aligned with the transflective pixels  1010  and include red, green, and blue color filters. 
   With continued reference to  FIG. 11A , a backlight  110  is located adjacent a rear polarizer  1050 . While a diffuser is usually located immediately following the backlight  110  such that it is between the backlight  110  and the rear polarizer  1050 , the collimating device  100  may eliminate the need for a diffuser. The collimating device  100  is adjacent the rear glass  1050 , such that the rear glass is disposed between the backlight  110  and the collimating device  100 . The optical element layer  250  is positioned between the collimating device  100  and the liquid crystal suspension  1030 . The liquid crystal suspension  1030  is also adjacent a front glass  1060 . The front glass is also adjacent a front polarizer  1070 . In an alternative embodiment (not shown), a rear glass is disposed between the optical element layer  250  and the liquid crystal suspension  1030 . In an alternative embodiment (not shown), the optical element layer  250  and collimating device  100  are separated and the collimating device  100  is positioned behind the front polarizer  1070 . In another alternative embodiment (not shown), both the optical element layer  250  and collimating device  100  are positioned behind the front polarizer  1070 . 
     FIG. 11B  illustrates another embodiment of a display  1100   b  employing transflective pixels  1010  and the optical element layer  250  of a transflector. In this embodiment, the color filters  1040  are not located in the liquid crystal suspension  1030 . Instead, the color filters are disposed between a rear polarizer  1050  and a rear glass  1080 . The collimating device  100  is located adjacent the backlight  110 , such that it is disposed between the backlight  110  and the optical element layer  250 . While a diffuser is usually located immediately following the backlight  110  such that it is between the backlight  110  and the rear polarizer  1050 , the collimating device  100  may eliminate the need for a diffuser. The rear polarizer  1050  is disposed between the optical element layer  250  and the color filters  1040 . The rear glass  1080  is disposed between the color filters  1040  and the liquid crystal suspension  1030 . A front glass  1060  is disposed between a front polarizer  1070  and the liquid crystal suspension  1030 , as in  FIG. 11A . In an alternative embodiment (not shown), the optical element layer  250  and collimating device  100  are separated such that the optical element layer  250  is positioned in front of the front polarizer  1070  but behind the color filters  1040 . 
   The collimating or transfecting device, or combination thereof, may be used as part of the backplane of an LCD. Placement of the transflecting device in the backplane would alleviate both color shifts and parallax effects arising from the reflective (ambient) component. This should be particularly applicable in flexible (so called plastic) displays. 
     FIG. 12  illustrates one embodiment of a light collimating or funneling device  1200  having first and second optical element layers  1210 ,  1220  with light funneling or collimating element  1240 . In this embodiment, each optical element layer  1210 ,  1220  is formed by lenticular channels whose vertical plane cross-section is four-sided (including, for example, a trapezoid or a figure with curved sides) and whose horizontal plane cross-section is a rectangle with length equal to that of the lenticular channel. As disclosed in earlier figures, the optical elements in both layers are tapered towards a backlight (not shown). 
   In this embodiment, the optical element layers  1210 ,  1220  are arranged so that the lenticular channels are orthogonal to each other. In other words, the horizontal plane rectangular bases of the optical elements in the first optical element layer  1210  are orthogonal to the horizontal plane rectangular bases of the optical elements in the second optical element layer  1220 . In an alternative embodiment (not shown), the lenticular channel of the first optical element layer  1210  are placed at an acute or obtuse angle with respect to the lenticular channels of the second optical element layer  1220 . In one embodiment, the second optical element layer  1220  (the layer farthest from the backlight) includes a metal layer  1230 . In an alternative embodiment (not shown), the upper layer does not include a metal layer. In another alternative embodiment (not shown), the structure  1200  includes a single layer of optical elements having rectangular cross-sections. 
   The structure  100 ,  200 ,  900 , or  1200  may be used with, for example, a non-emissive display system, such as a liquid crystal display (LCD), or other devices in which light is directed for the purpose of creating an image. A typical non-emissive display system of this type includes a stack comprised of a backlight, a polarizer, a liquid crystal suspension, and another polarizer. On occasion, glass plates may be layered in between each polarizer and the liquid crystal suspension. The structure  100 ,  200 ,  900 , or  1200  may be positioned between the backlight and the polarizer. In operation, ambient light will pass through the various layers of polarizers, glass plates (which may include color filters, common electrodes, TFT matrix, or other components), and liquid crystal suspension and will be redirected by reflective structures located on the inside of the back glass plate of the liquid crystal while at the same time artificial light rays generated from a backlight assembly will pass through the structure  100 ,  200 ,  900 , or  1200 . The structure  100 ,  200 ,  900 , or  1200  may also be included as part of a sub-assembly of an LCD or may be used in combination with other recycling films such as collimating or reflective polarizing films. The structure  100 ,  200 ,  900 , or  1200  may further be used as part of a sub-assembly in combination with an absorptive polarizing film, a reflective polarizing film, or both. 
   The structure  100 ,  200 ,  900 , or  1200  may be inserted between the backlight assembly and the liquid crystal module where the reflective surface or surfaces of the structure  100 ,  200 ,  900 , or  1200  faces the backlight assembly and the transmissive surface faces the liquid crystal module. 
   The typical distribution of light from an LCD backlight is Lambertian. Such a distribution is considered uncollimated. The structure  100 ,  200 ,  900 , or  1200  collimates the Lambertian distribution of the backlight to a prespecified angle of distribution. The prespecified angular distribution depends on the index of refraction of the light-containing polymer region, the length and shape of the light containing region, and the size of the input and output apertures. The reflective surface of the structure  100 ,  200 ,  900 , or  1200  may face the backlight assembly such that light emitted from the backlight assembly passes through the openings in the reflective surface to be eventually processed by the liquid crystal module. 
   Since space is usually at a premium inside an LCD, the overall thickness of the structure  100 ,  200 ,  900 , or  1200  should be minimized. In one embodiment, the overall thickness of the device is less than about 1000 microns. In alternative embodiments, the overall thickness is less than about 500 microns or even less than about 200 microns. In another alternative embodiment, the structure  100 ,  200 ,  900 , or  1200  is not limited to any pre-defined thickness. Rather, the thickness of the structure  100 ,  200 ,  900 , or  1200  is determined by its use and is not necessarily limited to 1000 microns. Likewise, the choice of periodicity is influenced by the LCD pixel periodicity. If periodicities for the device are smaller than the periodicities for the LCD, manufacturing defects in the device are less likely to be visible and result in rejection. Typical periodicities for the device could range from the sub-micron range to hundreds of microns. Typical input aperture widths also range from sub-microns to hundreds of microns. Special care must be taken when using sub-micron designs to deal with potential diffraction effects. Based on this range of possible designs, both nanoreplication and microreplication methods are likely to be used in manufacturing the device. Performance will be maintained when structure features are properly scaled. 
   A structure  100 ,  200 ,  900 , or  1200  can be positioned within a liquid crystal module itself in three configurations: (1) at the back (surface) of the rear glass of the liquid crystal module and in front of the polarizer, (2) at the back (surface) of the rear glass of the liquid crystal module and behind the polarizer, or (3) inside the rear glass of the liquid crystal module at the pixel level. For a two-polarizer liquid crystal display system, only the second configuration is possible for the display to process the light. For a single polarizer liquid crystal display system, all three configurations are possible. 
   Further, the overall thickness of the LCD may be minimized by employing integrated light management sub-assemblies with no air layers.  FIG. 13  illustrates one embodiment of an integrated sub-assembly  1300  comprising a backlight  110 , a light diffusing film  1310 , a collimating device  100 , a reflective polarizing film  1320 , a first absorptive polarizing film  1330 , a liquid crystal suspension  1030  having pixels  1340  and color filters  1040 , a second absorptive polarizing film  1350 , a glare control layer  1360 , and a privacy layer  1370 . It should be understood that the order of the elements of the illustrated sub-assembly  1300  is exemplary only. The only limitation is that the backlight  110  must be at one end of the sub-assembly  1300 . While a diffuser is usually located immediately following the backlight  110  such that it is between the backlight  110  and the rear polarizer  1050 , the collimating device  100  may eliminate the need for a diffuser. 
   It should also be understood that one or more of the illustrated elements may be omitted from the sub-assembly as desired. Further, it should be understood that the collimating device  100  of the sub-assembly  1300  may be any one of the previously disclosed light collimating devices or any other known light collimating device. 
   With continued reference to  FIG. 13 , a sub-assembly  1300  may include elements with no air layers between adjacent elements. In one embodiment, each element is optically coupled to the adjacent element(s). In an alternative embodiment, each element is laminated to the adjacent element(s). 
   For manufacturing, the sub-assembly  1300  may be composed of several sub-sub-assemblies. Each sub-sub-assembly may include at least one element of the sub-assembly  1300 . For example, a first sub-sub-assembly may consist of a backlight  110  and a light diffusing film  1310 ; a second sub-sub-assembly may consist of a collimating device  100  and a reflective polarizing film  1320 ; a third sub-sub-assembly may consist of a first absorptive polarizing film  1330 , a liquid crystal suspension  1030 , and a second absorptive polarizing film  1350 ; and a fourth sub-sub-assembly may consist of a glare control layer  1360  and a privacy layer  1370 . It should be understood that these sub-sub-assemblies are exemplary, and that any number or combination of elements may be included in a sub-sub-assembly. 
   The sub-sub-assemblies may be combined to form the complete sub-assembly  1300 . In one embodiment, the combined sub-sub-assemblies are attached such that no air layers exist within the sub-assembly  1300 . In an alternative embodiment (not shown), for ease of manufacturing, air layers exist between the sub-sub-assemblies. 
     FIG. 14  illustrates an alternative embodiment of a sub-assembly  1400  that may include a backlight  110 , a light diffusing film  1310 , a collimating device  100 , a reflective polarizing film  1320 , a first absorptive polarizing film  1330 , a liquid crystal module  1030  having pixels  1340  and color filters  1040 , a second absorptive polarizing film  1350 , a glare control layer  1360 , and a privacy layer  1370 . In the illustrated embodiment, the sub-assembly  1400  further includes a plurality of material layers  1410  disposed between each element of the sub-assembly  1400 , such that no air layers exist within the sub-assembly. In one embodiment, each material layer  1410  is a polymer layer. In an alternative embodiment, each material layer  1410  is a glass layer. In another alternative embodiment, each material layer  1410  is a pressure sensitive adhesive, structural adhesive, or other known bonding material. 
   The index of refraction of the material layer  1410  is considered relative to the index of refraction of the adjacent element. In one embodiment, the material layer  1410  has a lower index of refraction than the adjacent element. In alternative embodiments, the material layer  1410  has an index of refraction equal to or higher than that of the adjacent element. The index of refraction of the material may be selected to meet element performance requirements. A lower index of refraction material is used if the performance of the collimating device is controlled by an external air boundary. A matching index of refraction material is used if the performance of the collimating device is controlled by either an internal air boundary or an internal lower index of refraction material. 
   It should be understood that the order of the elements of the illustrated sub-assembly  1400  is exemplary only. The only limitation is that the backlight  110  must be at one end of the sub-assembly  1400 . 
   It should also be understood that one or more of the illustrated elements may be omitted from the sub-assembly as desired. Further, it should be understood that the light collimating device  100  of the sub-assembly  1400  may be any one of the previously disclosed light collimating devices or any other known light collimating device. 
   In one embodiment (not shown), the sub-sub-assemblies are formed without a material layer  1410  disposed between the elements. Instead, each element of the sub-sub-assembly is directly coupled to the adjacent element(s). For example, the elements may be optically coupled or directly laminated to each other. 
   For manufacturing, the sub-assembly  1400  may be composed of several sub-sub-assemblies. Each sub-sub-assembly would include at least one element of the sub-assembly  1400 . For example, a first sub-sub-assembly may consist of a backlight  110  and a light diffusing film  1310 ; a second sub-sub-assembly may consist of a collimating device  100  and a reflective polarizing film  1320 ; a third sub-sub-assembly may consist of a first absorptive polarizing film  1330 , a liquid crystal suspension  1030 , and a second absorptive polarizing film  1350 ; and a fourth sub-sub-assembly may consist of a glare control layer  1360  and a privacy layer  1370 . It should be understood that these sub-sub-assemblies are exemplary, and that any number or combination of elements may be included in a sub-sub-assembly. 
   The sub-sub-assemblies may then be combined to form the complete sub-assembly  1400 . In one embodiment, a material layer  1410  may be disposed between each sub-sub-assembly, such that no air layers exist and the resulting sub-assembly  1400  is uniform, as illustrated in  FIG. 14 . In an alternative embodiment (not shown), air layers may be permitted to exist between the sub-sub-assemblies. In another alternative embodiment (not shown), the sub-sub-assemblies are formed completely without a material layer disposed between the elements, as described in the preceding paragraph. In such an embodiment, a material layer  1410  may be disposed between each sub-sub-assembly to couple the sub-sub-assemblies together such that no air layers exist within the complete sub-assembly. 
     FIG. 15  illustrates an embodiment of a sub-assembly  1500  including a transflector  200 . It should be understood that the transflector  200  of the sub-assembly  1500  may be any one of the previously disclosed transflectors or any other known transflectors. The sub-assembly  1500  is otherwise substantially the same as the various embodiments of the sub-assembly  1300  discussed previously. As such, a discussion of the complete sub-assembly  1500  disclosed in  FIG. 15  will be omitted for brevity. 
     FIG. 16  illustrates an alternative embodiment of a sub-assembly  1600  including a transflector. It should be understood that the transflector  200  of the sub-assembly  1500  may be any one of the previously disclosed transflectors or any other known transflectors. 
   With continued reference to  FIG. 16 , the sub-assembly further includes a plurality of material layers  1410  disposed between the sub-assembly elements such that there are no air layers. In one embodiment, each material layer  1410  is a polymer layer. In an alternative embodiment, each material layer  1410  is a glass layer. In another alternative embodiment, each material layer  1410  is a pressure sensitive adhesive, structural adhesive, or other known bonding material. In one embodiment, the material layer  1410  has a lower index of refraction than the adjacent element. In alternative embodiments, the material layer  1410  has an index of refraction equal to or higher than that of the adjacent element. The index of refraction of the material may be selected to meet element performance requirements. A lower index of refraction material is used if the performance of the collimating device is controlled by an external air boundary. A matching index of refraction material is used if the performance of the collimating device is controlled by either an internal air boundary or an internal lower index of refraction material. 
   The sub-assembly  1600  is otherwise substantially the same as the various embodiments previously discussed. As such, a discussion of the complete sub-assembly  1600  disclosed in  FIG. 16  will be omitted for brevity. 
     FIG. 17  illustrates one embodiment of a sub-assembly  1700  having both a collimating device  100  and a transflector  200 . It should be understood that the light collimating device  100  of the sub-assembly  1700  may be any one of the previously disclosed light collimating devices or any other known light collimating device. Further, it should be understood that the transflector  200  of the sub-assembly  1700  may be any one of the previously disclosed transflectors or any other known transflectors. The sub-assembly  1700  is otherwise substantially the same as the various embodiments of the sub-assemblies  1300  and  1500  discussed in relation to  FIGS. 13 and 15 . As such, a discussion of the complete sub-assembly  1700  disclosed in  FIG. 17  will be omitted for brevity. 
     FIG. 18  illustrates an alternative embodiment of a sub-assembly  1800  having both a collimating device  100  and a transflector  200 . It should be understood that the light collimating device  100  of the sub-assembly  1800  may be any one of the previously disclosed light collimating devices or any other known light collimating device. Further, it should be understood that the transflector  200  of the sub-assembly  1800  may be any one of the previously disclosed transflectors or any other known transflectors. 
   With continued reference to  FIG. 18 , the sub-assembly further includes a plurality of material layers  1410  disposed between the sub-assembly elements such that no air layers exist. In one embodiment, each material layer  1410  is a polymer. In an alternative embodiment, each material layer  1410  is a glass layer. In another alternative embodiment, each material layer  1410  is a pressure sensitive adhesive, structural adhesive, or other known bonding material. In one embodiment, the material layer  1410  has a lower index of refraction than the adjacent element. In alternative embodiments, the material layer  1410  has an index of refraction equal to or higher than that of the adjacent element. The index of refraction of the material may be selected to meet element performance requirements. A lower index of refraction material is used if the performance of the collimating device is controlled by an external air boundary. A matching index of refraction material is used if the performance of the collimating device is controlled by either an internal air boundary or an internal lower index of refraction material. 
   The sub-assembly  1800  is otherwise substantially the same as the various embodiments of the sub-assemblies  1400  and  1600  discussed in relation to  FIGS. 14 and 16 . As such, a discussion of the complete sub-assembly  1800  disclosed in  FIG. 18  will be omitted for brevity. 
   The above described principles can be applied to known optical elements.  FIG. 19  illustrates a prior art assembly  1900  that includes a prior art collimating device  1910 , and a second optical element  1920  separated by an air layer that manages light control. Elements are considered separated by a layer of air when the films are not optically coupled or joined by a non-gaseous medium (i.e., a medium other than air). In one known embodiment, the prior art collimating device  1910  is a 3M BRIGHTNESS ENHANCING FILM®. The second optical element may be a reflective polarizer, an absorptive polarizer, a transflector, a light diffusing film, a backlight, or a liquid crystal suspension. In the illustrated embodiment, the external air boundary of the prior art collimating device  1910  controls light management as light passes through the prior art collimating device  1910  and the second optical element  1920 . 
     FIGS. 20A and 20B  illustrate perspective and front plan views, respectively, of a prior art assembly  2000  that includes a prior art collimating device  2010  that includes at least a first collimator  2020  and a second collimator  2030  separated by an air layer. Each of the first and second collimators  2020 ,  2030  includes lenticular channels that define optical elements. In the illustrated embodiment, the first and second collimators  2020 ,  2030  are aligned such that the lenticular channels of the first collimator  2020  are substantially orthogonal to the lenticular channels of the second collimator  2030 . In an alternative embodiment (not shown), the first and second collimators  2010 ,  2020  are aligned such that the lenticular channels of the first collimator  2020  are substantially parallel to the lenticular channels of the second collimator  2030 . In another alternative embodiment (not shown), the lenticular channels of the first collimator  2020  are at an acute angle with respect to the lenticular channels of the second collimator  2030 . 
   With continued reference to  FIGS. 20A and 20B , the prior art assembly  2000  further includes a second optical element  1920  separated from the collimating device by an air layer. In one known embodiment, the each of the first and second collimators  2020 ,  2030  is a 3M BRIGHTNESS ENHANCING FILM®. The second optical element  1920  may be a reflective polarizer, an absorptive polarizer, a transflector, a light diffusing film, a backlight, or a liquid crystal suspension. In the illustrated embodiment, the air layers between the first and second collimators  2020 ,  2030  and the second optical element  1920  controls light management as light passes through the prior art collimating device  2010  and the second optical element  1920 . 
     FIG. 21  illustrates one embodiment of a sub-assembly  2100  that includes the prior art collimating device  1910  and the second optical element  1920 , where the external air boundary is eliminated. In this embodiment, the air layer is replaced by a material layer  1410 . The material layer  1410  may be glass, a polymer, a pressure sensitive adhesive, or a structural adhesive. In one embodiment, the material layer  1410  has a lower index of refraction than either of the prior art collimating device  1910  or the second optical element  1920 . 
   In the illustrated embodiment, the channels between the optical structures of the prior art collimating device  1910  are shown partially filled with the material of the layer  1410  to provide sufficient surface to adhere the material layer  1410  and the prior art collimating device  1910  together. In an alternative embodiment (not shown), the material layer  1410  may fill the entire channel between the optical structures of the collimating device  1910 . While gaps may exist on a microscopic level between the prior art collimating device  1910 , the material layer  1410 , and the second optical element  1920 , the air layer is understood to be eliminated because such microscopic air gaps do not control light management or otherwise affect the path of the light. 
     FIG. 22  illustrates an alternative embodiment of a sub-assembly  2200  that includes a prior art collimating device  2010  that includes a first collimator  2020  and a second collimator  2030 , a second optical element  1920 , wherein air layers are eliminated between elements. In the illustrated embodiment, both of the air layers are replaced by a material layer  1410 . The material layers  1410  may be glass, a polymer, a pressure sensitive adhesive, a structural adhesive or a combination thereof. The channels between one or both of the optical structures are partially filled with the material of the layer  1410  to provide sufficient surface to adhere the material layer  1410  and the optical element layer  2010  together. In another embodiment (not shown), the material layer  1410  may fill the entire space between the structures of optical elements of the first and second collimators  2020 ,  2030 . In one embodiment, the material layer  1410  has a lower index of refraction than the prior art collimating device  2010 . 
   The LCD can be manufactured on a roll-to-roll or assembled-by-layer basis for any of the embodiments described and the light collimating or funneling structure  100 ,  200 ,  900 , or  1200  can be an integral part of the stack. The layers of the LCD stack are produced or assembled on a layer-by-layer basis, and the structure  100 ,  200 ,  900 , or  1200  can be incorporated as a part of the glass, pixel, collimator, or polarizer. Functional components may be layered on a liquid crystal module substrate, thereby permitting the structure  100 ,  200 ,  900 , or  1200  to be constructed as part of the overall liquid crystal module manufacturing process. 
   In one embodiment, a non-emissive display system may collimate light such that the majority of light emerges perpendicular to the device. The non-emissive display system may also include a light polarizer. In any embodiment, the collimating or polarizing material may be attached to the reflective or transmissive side of the device. The highly transmissive surface of the structure  100 ,  200 ,  900 , or  1200  may face the liquid crystal module and the highly reflective surface may face the backlight assembly. The collimating or polarizing material can be attached to the entire transmissive surface of the structure  100 ,  200 ,  900 , or  1200 . The collimating or polarizing materials may be an integrated design element and part of the manufactured product. Alternatively, the material may be later adhered or fixed to either surface of the structure  100 ,  200 ,  900 , or  1200 . In one embodiment, the collimating film may cover the entire area of the surface where the light emerges from the structure  100 ,  200 ,  900 , or  1200 . The collimating film may cover the full area of the display or at least a portion thereof. 
   Another way to collimate light is to include lens-lets within the liquid crystal display system. The location could be either an integral with the structure  100 ,  200 ,  900 , or  1200  or separate from it, the location of the lens-lets may be directly above or underneath the structure  100 ,  200 ,  900 , or  1200 . 
   The optical elements described herein have the ability to allow light to pass from the backside, while the front surface of the film can potentially be used to absorb, direct, reflect, or deflect the ambient light. A modification of the transflective film can be used in an organic Light Emitting Diode (OLED) display by taking the original transflective design and replace the upper reflective metal area with light absorbing or directing material. The film sits between the OLED pixels (light source) and the top glass. This controls the effect of ambient light (effectively unwanted glare) in the emissive OLED display. There is also a traditional (non-OLED) transmissive LCD application that would benefit from this design. This design to control glare and improve contrast can be used with any emissive display. This design, as in the transflective design, could be deployed as a film or as a component of the pixel surface. 
   There are at least four methods of microreplication manufacturing for the above-described devices. The first method involves creation of a master mold and then the creation of the device. The master mold can be manufactured utilizing a diamond turning process or a photolithographic process (including any part of the electromagnetic spectrum such as X-ray lithography for LIGA as an example). To create the repeated structures of the device, a mechanical process such as embossing or molding or a chemical process such as etching can be utilized. Thus, utilizing these processes, the structures may be formed in the body of a transparent film material, glass, or plastic substrate by creating indentations (voids) in the transparent material. Light containing regions of the transparent material are then delineated by these indentations. Manufacturing techniques using transparent photosensitive materials where physical indentations are not formed will be described below. 
   The indentations may then be filled with either a reflective material or a material that has a lower index of refraction than that of the transparent film material. The indentations in the transparent film material may be embedded in the transparent film material such that the base of each shape is approximately parallel to and coincident with, or slightly recessed from, the transparent material. If the reflective fill material has a lower index of refraction than the transparent film material, light will be contained in the transparent material. 
   To accommodate either of these processes, the transparent film material has specific properties necessary for etching, molding, embossing, or other processes that alter the body of the device. Examples of suitable materials are polymers such as polycarbonate and PMMA (polymethylmethacrylate). Examples of reflective material for filling the indentations include a metal composite or other material with a high reflectivity such as aluminum, gold, silver, nickel, chrome, a dielectric or other metallic alloy with a reflectivity of 80% or greater. In one embodiment, the reflectivity of the material is 95% or greater. The fill material for the reflective structures will be optimized to minimize absorption and have highly reflective properties for the controlled redirection of energy. Examples of fill material that has a lower index of refraction than that of the transparent film material include clear composite paste, composite material (e.g., polymer), or multiple composite materials with different refractive indices or reflective qualities. In an alternative embodiment, no material (e.g., gas, air, or vacuum) may be used to fill the indentations. 
   The minimum difference in index of refraction between the fill and the body of the element is estimated to be 0.05 to achieve TIR of that portion such that light does not leak by refraction through the boundary of the light-containing region. The index of refraction difference may not be the same for each shape across the body of the device, as long as there is sufficient index of refraction difference between the fill and the body of the element so that some of the light undergoes TIR and does not leak from the light-containing region. Preferably, however, the indices of refraction are the same for each shape across the body of the device. Furthermore, a portion of the indentations may be filled with a first material and then a second portion of the indentation may be filled with a second material. For example, the top of the indentation may be filled with aluminum while the rest of the indentation may be filled with a clear polymer having a lower index of refraction than that of the transparent film material. 
   A second method of manufacturing the above-described devices produces the structures in a transparent photosensitive film. The structures are produced by changing the index of refraction in specific areas of the body of the transparent photosensitive film to have the equivalent function and shape of the collimating or transflector structures herein described, wherein the function and shape may be the same. 
   As in the manufacturing technique using microreplication, the equivalent appropriate structures are created whereby the high index of refraction structures become the light-containing regions and the low index of refraction regions act as the light-guiding boundary regions. The process includes forming a transparent photosensitive film on the surface of a substrate (for example, by deposition). The transparent photosensitive film may be constructed of any clear material that, when exposed to light, changes its optical properties. The photosensitive material should exhibit favorable optical and mechanical properties. In addition to a sufficient photo-induced refractive index change, a suitable set of “writing” wavelengths (typically in the ultraviolet), optical transparency, thin film formability, and mechanical behavior are of great importance. The transparent photosensitive film may be “written” by scanning over the surface with a repeated pattern or over a larger volume through a micro-lenslet array. 
   Examples of materials used in this process include OLEDs or organic polymers that have optimized mechanical behavior, or organic-inorganic hybrids that combine the chemical versatility of organic polymers, i.e. polysilanes, polygermanes, and/or their sol-gel hybrids. Other materials include organic polymer such as specially modified polyethylene, polycarbonate, polyvinylcinnamate, and polymethylmethacrylate. Other materials include the combination a transparent polymer matrix and a polymerable photo-reactive substance comprising a photopolymerizable monomer. The transparent polymer matrix may be selected from the group consisting of polyolefins, synthetic rubbers, polyvinyl chloride, polyester, polyamide, cellulose derivatives, polyvinyl alcohol, polyacrylates, polymethacrylates, polyurethane, polyurethane acrylate, and epoxy acrylate resin. The photo-reactive substance comprises a photo-reactive initiator which has a refractive index regulating activity and said film has a distribution of a refractive index. The photopolymerizable monomer may be selected from the group consisting of tri-bromophenoxyethyl acrylate and trifluoroethyl acrylate. 
   A thin layer of reflective material is then deposited on the surface of the photosensitive transparent film opposite the substrate. In one embodiment, the reflective material for the thin layer of reflective metal is a metal composite or other material with a high reflectivity such as aluminum, gold, silver, nickel, chrome, a dielectric or other metallic alloy with a reflectivity of 80% or greater. Preferably, the reflectivity of the material is 95% or greater. Predetermined regions of the reflective metal deposition are then removed by ablating the reflective material to expose the photosensitive film in the predetermined regions. These predetermined regions are then exposed to a light source to change the optical characteristics of the photosensitive film in the predetermined regions to alter the index of refraction of the photosensitive film in the predetermined regions to thereby form altered refractive index areas. The steps of ablating the reflective metal and changing the optical characteristics of the photosensitive film are accomplished by a light source (that faces the metal reflective layer) that may produce ultraviolet light. The light source may comprise an optical radiation source that irradiates light, at a specific wavelength and of sufficient intensity, through a micro-lenslet array so as to ablate the reflective metal layer and change the optical characteristics of the photosensitive film. In one embodiment, the radiation source is an excimer laser. 
   The unchanged portions of the photosensitive film comprise unaltered refractive index areas (i.e., structures) having a lower index of refraction than the altered refractive index areas. 
   A third method of manufacturing also produces the desired structures in a transparent photosensitive film. The process also includes forming a transparent photosensitive film on the surface of a substrate. The transparent photosensitive film may be constructed of the same materials as discussed above. A photoresist layer is then formed on the photosensitive film. Predetermined regions of the photosensitive film and the photoresist layer are then exposed to a light source (that faces the substrate) to change the optical characteristics of the photosensitive film in the predetermined regions and to alter the index of refraction of the photosensitive film in the predetermined regions to thereby form altered refractive index areas in the photosensitive film. The light source may comprise an optical radiation source that irradiates light, at a specific wavelength and of sufficient intensity, through a micro-lenslet array so as to ablate the reflective metal layer and change the optical characteristics of the photosensitive film. Preferably, the radiation source is an Excimer laser. The exposed photoresist layer in the predetermined region is then removed using a suitable etchant that creates an opening to the photosensitive film. A thin layer of reflective material is then deposited in the openings previously occupied by the exposed photoresist layer. In one embodiment, the reflective material for the thin layer of reflective metal is a metal composite or other material with a high reflectivity such as aluminum, gold, silver, nickel, chrome, a dielectric or other metallic alloy with a reflectivity of 80% or greater. In one embodiment, the reflectivity of the material is 95% or greater. Finally, the residual photoresist layer is washed away and lifted off, removing the unwanted material that was on the residual photoresist layer leaving the desired pattern on the remainder of the surface. 
   A fourth manufacturing method for creating the above-described devices includes a single step process of producing the desired structures in a transparent photosensitive film. In this method, CPC or approximate CPC structures are manufactured from a photosensitive polymer by exposing the output side of the structure to a laser light, using a lens/masking system. The photosensitive polymer reacts to the laser light in a pre-determined frequency band by changing its index of refraction in appropriately selected areas. A printing system is guided by the light output from the structures created by the change in index of refraction. Simultaneously then, a reflective layer surrounding the input apertures can be manufactured by printing a reflecting layer whenever there is no light. To complete the process, a simple blanket polymer deposition on the input aperture side is performed to immerse the reflecting layer. 
   In other embodiments related to utilizing a photosensitive transparent material, discrete structures may be arranged in varying structures, heights, angles, or spacing and one or more of the discrete faces of a structure, may be concave, convex, and/or pitted. Additionally, micro-shapes (such as pyramids or cones) may be deposited on one side of the body of the element directly over the base of each structure, either as part of a deposition process, described above, or as an independent process, to further control the direction of reflected energy. In other embodiments, the indices of refraction may be different for each discrete structure such that various alternating patterns are produced across the body of the element to achieve specific effects. In other embodiments, a combination of structures created by filled indentations and altering the refractive index of a photosensitive material may be used to create various patterns across the body of the element. In one embodiment, a reflective material such as metal or any material with the equivalent of an infinite index of refraction may be inserted underneath the polymer-cladding layer (layer of lower index of refraction material) to reflect light exceeding the cladding&#39;s index of refraction critical angle. This will reflect light normally lost by reflecting light back into the wave-guide region. This technique may be used for all structure sizes defined above. 
   Another method of creating the above described devices includes fabrication of structures from some suitable material that will maintain integrity in the physical working environment, and suspending the structures by some suitable method. Suspension may be accomplished by the use of wire or some type of filament that forms a grid, but will depend on the specific application and will be apparent to one skilled in the art. This aspect of the invention is useful in solar applications or other applications, where the size of transflectors may or may not be limited by the size requirements of non-emissive displays (where the intended use is by the human visual system). 
   Another method to manufacture light-guiding structures is to directly locate structures on top of a supporting surface such as glass or polymer. One preferred embodiment is an isosceles shaped light-guiding structure made of metal or a highly reflective material resting on glass. The wave guide structures are laid on top of or deposited on the underlying supporting surface. Another preferred embodiment is where the supporting surface contains periodic shapes (grooved or projection) wherein a fluid containing the appropriate mating pieces is passed over the periodic shapes of the supporting surface such that the probability of creating the desired device is 100%. This can be accomplished as in biological systems by having a sufficient number of the mating pieces carried in the fluid in excess of the shapes on the supporting structure. 
   While the present application illustrates various embodiments, and while these embodiments have been described in some detail, it is not the intention of the applicant to restrict or in any way limit the scope of the claimed invention to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention, in its broader aspects, is not limited to the specific details, the representative apparatus, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the applicant&#39;s claimed invention.