权利要求：
1. A display device component comprising:
an optical waveguide having a smooth front surface and a smooth back surface;
a non-white material formed on a portion of said smooth back surface of said optical waveguide, said non-white material forming a pattern on said smooth back surface of said optical waveguide, said non-white material having a first surface adjacent to said smooth back surface of said optical waveguide and a second surface away from said smooth back surface of said optical waveguide, said second surface of said non-white material being smooth;
a first material formed on said second surface of said non-white material, said first material having light scattering properties to frustrate a portion of totally internally reflected light within said optical waveguide such that when said optical waveguide is illuminated by a light source, said pattern formed by said non-white material is visible by viewing said smooth front surface of said optical waveguide and said pattern formed by said non-white material is visible by viewing said smooth back surface of said optical waveguide; and
a second material formed on said smooth front surface of said optical waveguide, said second material forming a pattern on said front smooth surface of said optical waveguide, said second material having a first surface adjacent to said smooth front surface of said optical waveguide and a second surface away from said smooth front surface of said optical waveguide, said second surface being non-smooth, said non-smooth second surface frustrating a portion of light being internally reflected within said optical waveguide.
2. The display device component as claimed in claim 1, wherein said non-white material is a non-white marking material.
3. The display device component as claimed in claim 1, wherein said first material is a white marking material.
4. The display device component as claimed in claim 1, wherein said second material is a non-white colored marking material.
5. The display device component as claimed in claim 1, wherein said second material is a non-white colored marking material having a color distinct from a color of said non-white material.
6. A display device component comprising:
an optical waveguide having a smooth front surface and a smooth back surface;
a first material formed on a portion of said smooth back surface of said optical waveguide, said first material having a smooth first surface adjacent to said smooth back surface of said optical waveguide and a smooth second surface away from said smooth back surface of said optical waveguide, said first material having light scattering particles embedded therein, said embedded light scattering particles frustrating a portion of totally internally reflected light within said optical waveguide; and
a second material formed on said smooth front surface of said optical waveguide, said second material having a smooth first surface adjacent to said smooth front surface of said optical waveguide and a smooth second surface away from said smooth front surface of said optical waveguide, said second material having light scattering particles embedded therein, said embedded light scattering particles frustrating a portion of totally internally reflected light within said optical waveguide.
7. The display device component as claimed in claim 6, wherein said first material is a white marking material.
8. The display device component as claimed in claim 6, wherein said second material is a white marking material.
9. A display device component comprising:
an optical waveguide having a smooth front surface and a smooth back surface;
a first material formed on a portion of said smooth front surface of said optical waveguide material, said first material having light scattering particles embedded therein;
a non-white material formed on said first material, said non-white material forming a pattern; and
a second material formed on said smooth back surface of said optical waveguide, said second material forming a pattern, said second material having light scattering particles embedded therein, said embedded light scattering particles frustrating a portion of totally internally reflected light within said optical waveguide such that when said optical waveguide is illuminated by a light source, said pattern formed by said second material is visible by viewing said smooth front surface of said optical waveguide and said pattern formed by said second material is visible by viewing said smooth back surface of said optical waveguide;
said light scattering particles embedded in said first material frustrating a portion of totally internally reflected light within said optical waveguide such that when said optical waveguide is illuminated by a light source, said pattern formed by said non-white material is only visible by viewing said smooth front surface of said optical waveguide and said pattern formed by said non-white material is not visible by viewing said smooth back surface of said optical waveguide.
10. The display device component as claimed in claim 9, wherein said first material is a white marking material.
11. The display device component as claimed in claim 9, wherein said second material is a non-white marking material.
12. The display device component as claimed in claim 9, wherein said third material is a white colored marking material.
13. A display device component comprising:
an optical waveguide having a smooth front surface and a smooth back surface;
a non-white material formed on a portion of said smooth front surface of said optical waveguide material, said non-white material forming a pattern; and
a material formed on said smooth back surface of said optical waveguide, said material forming a pattern, said material having light scattering particles embedded therein, said embedded light scattering particles frustrating a portion of totally internally reflected light within said optical waveguide such that when said optical waveguide is illuminated by a light source, said pattern formed by said non-white material is visible by viewing said smooth front surface of said optical waveguide and said pattern formed by said material is visible by viewing said smooth back surface of said optical waveguide and by viewing said smooth front surface of said optical waveguide.
14. The display device component as claimed in claim 13, wherein said first material is a non-white marking material.
15. The display device component as claimed in claim 13, wherein said second material is a white marking material.
16. A display device component comprising:
a first optical waveguide having a smooth first surface and a smooth second surface;
a second optical waveguide having a smooth third surface and a smooth fourth surface;
a first material formed on a portion of said smooth first surface of said first optical waveguide;
a second material formed on said first material, said second material forming a pattern;
a third material formed on a portion of said smooth second surface of said first optical waveguide, said third material forming a pattern;
a fourth material formed on said third material;
said first material having light scattering particles embedded therein, said embedded light scattering particles frustrating a portion of totally internally reflected light within said first optical waveguide such that when said first optical waveguide is illuminated by a light source, said pattern formed by said second material is only visible by viewing said smooth first surface of said first optical waveguide and said pattern formed by said second material is not visible by viewing said smooth second surface of said first optical waveguide;
said fourth material having light scattering particles embedded therein, said embedded light scattering particles frustrating a portion of totally internally reflected light within said first optical waveguide such that when said first optical waveguide is illuminated by a light source, said pattern formed by said third material is visible by viewing said smooth first surface of said first optical waveguide;
a fifth material formed on a portion of said smooth third surface of said second optical waveguide;
a sixth material formed on said fifth material, said sixth material forming a pattern;
a seventh material formed on a portion of said smooth fourth surface of said second optical waveguide, said seventh material forming a pattern;
an eighth material formed on said seventh material;
said fifth material having light scattering particles embedded therein, said embedded light scattering particles frustrating a portion of totally internally reflected light within said second optical waveguide such that when said second optical waveguide is illuminated by a light source, said pattern formed by said sixth material is only visible by viewing said smooth first surface of said first optical waveguide and said pattern formed by said sixth material is not visible by viewing said smooth second surface of said second optical waveguide;
said eighth material having light scattering particles embedded therein, said embedded light scattering particles frustrating a portion of totally internally reflected light within said second optical waveguide such that when said second optical waveguide is illuminated by a light source, said pattern formed by said seventh material is visible by viewing said smooth first surface of said optical waveguide.
17. The display device component as claimed in claim 16, wherein said first optical waveguide is spaced apart from said second optical waveguide.
18. The display device component as claimed in claim 17, wherein a distance between said first optical waveguide and said second optical waveguide is equal to half a thickness of said first optical waveguide.
19. The display device component as claimed in claim 17, wherein said first optical waveguide is parallel to said second optical waveguide.
20. A display device component comprising:
a plurality of optical waveguides, each optical waveguide having a smooth front surface and a smooth back surface;
each optical waveguide guide having formed thereon a first material formed on a portion of said smooth front surface of each optical waveguide, said first material having light scattering particles embedded therein;
each optical waveguide guide having, formed on said first material, a second material, said second material forming a pattern;
each optical waveguide guide having formed thereon a third material formed on a portion of said smooth back surface of each optical waveguide, said third material forming a pattern;
each optical waveguide guide having, formed on said third material, a fourth material, said fourth material having light scattering particles embedded therein;
said light scattering particles embedded in said first material frustrating a portion of totally internally reflected light within each optical waveguide such that when each optical waveguide is illuminated by a light source, said pattern formed by said first material is only visible by viewing said smooth front surface of each optical waveguide and said pattern formed by said first material is not visible by viewing said smooth back surface of each optical waveguide;
said light scattering particles embedded in said fourth material frustrating a portion of totally internally reflected light within each optical waveguide such that when each optical waveguide is illuminated by a light source, said pattern formed by said fourth material is only visible by viewing said smooth front surface of each optical waveguide and said pattern formed by said fourth material is not visible by viewing said smooth back surface of each optical waveguide.
21. The display device component as claimed in claim 20, wherein a distance between each optical waveguide is equal to a thickness of an optical waveguide divided by a number of optical waveguides.
22. The display device component as claimed in claim 20, wherein each optical waveguide is parallel thereto.
23. A display device component comprising:
a plurality of optical waveguides, each optical waveguide having a smooth front surface and a smooth back surface;
each optical waveguide guide having formed thereon a first material formed on a portion of said smooth front surface of each optical waveguide, said first material forming a pattern, said first material having a first surface adjacent to the smooth front surface of the optical waveguide and a second surface away from the smooth front surface of the optical waveguide, the second surface being non-smooth, said non-smooth second surface frustrating a portion of light being internally reflected within said optical waveguide such that when each optical waveguide is illuminated by a light source, said pattern formed by said first material is visible by viewing said smooth front surface of each optical waveguide;
each optical waveguide guide having formed thereon a second material formed on a portion of said smooth back surface of each optical waveguide, said second material forming a pattern;
each optical waveguide guide having, formed on said second material, a third material, said third material having light scattering particles embedded therein, said embedded light scattering particles frustrating a portion of totally internally reflected light within said optical waveguide such that when each optical waveguide is illuminated by a light source, said pattern formed by said second material is visible by viewing said smooth front surface of each optical waveguide.
24. The display device as claimed in claim 23, wherein a distance between each optical waveguide is equal to a thickness of an optical waveguide divided by a number of optical waveguides.
25. The display device as claimed in claim 23, wherein each optical waveguide is parallel thereto.
具体实施方式：
DETAILED DESCRIPTION OF THE DRAWINGS
[0049]For a general understanding, reference is made to the drawings. In the drawings, in some instances, like references have been used throughout to designate identical or equivalent elements. It is also noted that the drawings may not have been drawn to scale and that certain regions may have been purposely drawn disproportionately so that the features and concepts may be properly illustrated.
[0050]As noted above, optical waveguides have been utilized to provide a vehicle to display images. The displaying of the images utilizes the principles of Snell's Law.
[0051]According to Snell's Law, the critical angle is the angle of incidence for which the angle of refraction is 90°. The angle of incidence is measured with respect to the normal (z-axis) at the refractive boundary, as illustrated in FIG. 4.
[0052]As illustrated in FIG. 4, a light ray passes from glass (n1) into air (n2). The light emanating from the interface (x-axis) is bent (angle θt) towards the glass (n1). When the incident angle (angle θi) is increased sufficiently, the transmitted angle (in air) reaches 90 degrees. It is at this point no light is transmitted into air. The critical angle θc is given by Snell's law:
n1 sin θi=n2 sin θt
[0053]To determine the angle of incidence for no refraction, Snell's Law is rearranged as follows:
[0054]sin<mspace width="0.3em" height="0.3ex"/>θi=n2n1sin<mspace width="0.3em" height="0.3ex"/>θt
[0055]To find the critical angle, solve for the value for θi when θt=90°, and thus, sin θt=1 sin θt=1. The resulting value of θi is equal to the critical angle θc.
[0056]Solving for θi, the equation for the critical angle is as follows:
[0057]θc=θi=arcsin(n2n1)θc=θi=arcsin(n2n1)
[0058]If the incident ray is precisely at the critical angle θc, the refracted ray is tangent to the boundary at the point of incidence (x-axis in FIG. 4).
[0059]For example, if light was traveling through an optical waveguide; such as acrylic or glass; (with an index of refraction of 1.55) into air (with an index of refraction of 1.00), the calculation would give the critical angle for light from the optical waveguide into air as follows:
[0060]θc=arcsin(1.001.55)=41.8
[0061]In this example, light incident on the border (x-axis in FIG. 4) with an angle less than 41.8°, with respect to normal (z-axis in FIG. 4), will be partially transmitted, while light incident on the border at larger angles, with respect to normal (z-axis in FIG. 4), would be totally internally reflected.
[0062]It is noted that if the fraction n2/n1 is greater than 1, the arcsine is not defined, meaning that total internal reflection does not occur even at very shallow or grazing incident angles. The critical angle is only defined when n2/n1 is less than or equal to 1.
[0063]FIG. 5 shows another example of refraction of light at the interface between two mediums (air and water). As illustrated in FIG. 5, when the incident angle θ1 of light travelling from water to air is less than the critical angle θc, the light is refracted at angle θ2. On the other hand, as illustrated in FIG. 5, when the incident angle θ1 of light travelling from water to air is the critical angle θc, the light is refracted to travel parallel to the water/air interface. Lastly, as illustrated in FIG. 5, when the incident angle θ1 of light travelling from water to air greater than the critical angle θc, the light is reflected at angle θ2 to cause a total internal reflection of the incident light.
[0064]An alternative to the conventional engraving of an image on a transparent medium (optical waveguide) is to print directly onto the transparent medium (optical waveguide) with marking materials, such as liquid inks, UV curable inks, toners, solid inks, etc., using a printing system.
[0065]In the various embodiments described below, an optical waveguide having an index of refraction significantly different from the surrounding medium (such as air) is utilized. For example, an optical waveguide made of acrylic having an index of refraction of about 1.5 may be utilized when the surrounding medium is air, having an index of refraction of about 1.
[0066]Moreover, in the various embodiments described below, marking materials having an index of refraction substantially equal to the index of refraction of the optical waveguide is utilized.
[0067]For example, a marking material having an index of refraction of about 1.4 may be utilized when the underlying optical waveguide has an index of refraction of about 1.5.
[0068]Given the examples discussed above, there are certain angles of light incidence (such as light emanating from a LED source) that cause the incident light to be totally internally reflected at an optical waveguide-air boundary, but partially externally refracted at an optical waveguide-marking material(s) boundary.
[0069]These differences in indices of refraction enable the containment of the incident light within the optical waveguide in regions where there is(are) no marking material(s), while releasing light in regions where there is(are) marking material(s).
[0070]Upon having the light enter the marking material, to realize illumination of the image, the light or a portion thereof must exit the marking material so as to prevent the light from being totally internally reflected at the marking material-air interface.
[0071]More specifically, if the top surface of the marking material is smooth, the angles of incidence at the marking material-air interface are such that the light will internally reflect within the marking material and not exit into the air and towards the viewer.
[0072]To enable the refraction of the light at the marking material-air interface to enable the light to exit the marking material, FIG. 6 illustrates an optical waveguide 10, wherein a white marking material 40 is printed on a viewing (30) surface of the optical waveguide 10. Thereafter, another (colored) marking material 50 is printed on top of the white marking material 40.
[0073]It is noted that the marking material 40 may be a clear marking material with light scattering properties or light scattering particles embedded therein.
[0074]It is further noted that the marking material 40 has light scattering properties or has light scattering particles embedded therein so that the incident light, from a light source 20, is scattered at multiple angles so that at least one of the angles of the scattered light will be incidence upon the marking material-air interface at an angle less than the critical angle so that the light may exit the marking material 50 into the air.
[0075]It is noted that the index of refraction of the white marking material 40 is substantially equal to the index of refraction of the optical waveguide 10 so that light will exit the optical waveguide 10 and penetrate the white marking material 40.
[0076]The white marking material 40 causes the entering light to scatter in all directions, some of which will exit the white marking material 40, travel in a straight line through the marking material 50 because the index of refraction of the white marking material 40 is substantially equal to the index of refraction of the marking material 50. Based upon the angle of incidence, some of the light entering the marking material 50 will externally refract at the marking material-air interface and travel towards the viewer (30).
[0077]FIG. 7 is a graphical illustration of the pathway of light in the printed on optical waveguide 10 of FIG. 6. As illustrated in FIG. 7, incidence light 25 is internally reflected within the optical waveguide 10. At the optical waveguide-white marking material interface, since the index of refraction of the white marking material 40 is substantially equal to the index of refraction of the optical waveguide 10, the incidence light 25 will exit the optical waveguide 10 and penetrate the white marking material 40.
[0078]Upon encountering an embedded scattering particle 45, the incidence light 25 is scattered at multiple angles to create scattered light 26. At the white marking material-marking material interface, since the index of refraction of the white marking material 40 is substantially equal to the index of refraction of the marking material 50, the scattered light 26 will exit the white marking material 40 and penetrate the marking material 50.
[0079]At the marking material-air interface, since the index of refraction of the marking material 50 is substantially different from the index of refraction of air, light 27 (refracted) will exit the marking material 50 into the air when the angle of incidence of the scattered light 26 is less than the critical angle of the marking material-air interface.
[0080]Moreover, to enable the refraction of the light at the marking material-air interface to enable the light to exit the marking material, FIG. 8 illustrates another example of an optical waveguide 10, wherein a (colored) marking material 50 is printed on a viewing (30) surface of the optical waveguide 10. In this embodiment, a top surface 55 of the marking material 50 is formed so that the top surface 55 is rough, emulating an engraved surface.
[0081]It is noted that the index of refraction of the marking material 50 is substantially equal to the index of refraction of the optical waveguide 10 so that light, from a light source 20, will exit the optical waveguide 10 and penetrate the marking material 50.
[0082]Thus, based upon the angle of incidence of the light interacting with the rough surface of the marking material-air interface, some of the light entering the marking material 50 will externally refract at the marking material-air interface and travel towards the viewer (30).
[0083]FIG. 9 is a graphical illustration of the pathway of light in the printed on optical waveguide 10 of FIG. 8. As illustrated in FIG. 9, incidence light 25 is internally reflected within the optical waveguide 10.
[0084]At the optical waveguide-marking material interface, since the index of refraction of the marking material 50 is substantially equal to the index of refraction of the optical waveguide 10, the incidence light 25 will exit the optical waveguide 10 and penetrate the marking material 50.
[0085]At the marking material-air interface, since the index of refraction of the marking material 50 is substantially different from the index of refraction of air, light 27 (refracted) will exit the marking material 50 into the air when the angle of incidence of the light 25 is less than the critical angle of the encountered surface of the marking material-air interface.
[0086]FIG. 10 is a table providing a summary of the various optical paths through an optical waveguide, as illustrated in FIGS. 6 and 7. More specially, the optical path is defined as light entering the optical waveguide on the left from an illumination source (LED).
[0087]The light is then refracted at an air-optical waveguide interface and internally reflected at multiple optical waveguide-air interfaces for all angles. The light is partially externally refracted at the optical waveguide-white marking material interface, for some angles, and scattered by the scattering particles in the white marking material.
[0088]The scattered light travels straight through the colored marking material (since the marking materials have similar indices of refraction) and then, since the scattering created many angles of incidence at the colored marking material-air boundary, much of the light exits the colored marking material and travels towards the viewer.
[0089]As shown in FIG. 10, on the far left, light enters the optical waveguide (for example, from an LED) with angles of incidence θi ranging from 0 to 90 degrees. The shown refracted angles θr1 are computed on the basis of Snell's law. The rays of light along the θr1 paths strike an optical waveguide-air boundary such that for all possible θr1, the light will be totally internally reflected within the optical waveguide (indicated by #NUM! in dashed boxes 61). The value, #NUM!, indicates that there is no solution for a refracted ray.
[0090]After bouncing back and forth within the optical waveguide, the light rays will strike the optical waveguide-white marking material boundary at the same angles as it had struck the optical waveguide-air boundary.
[0091]However, since the difference in index of refraction between air (1.0) and the white marking material (for example, 1.4) and depending on the angle of incidence, some of the light is externally refracted into the white marking material instead of being internally reflected within the optical waveguide. The cells within the dashed boxes 62 in FIG. 10 identify the light rays that will be completely internally reflected at the optical waveguide-air interface and partially externally refracted at the optical waveguide-white marking material interface. Thus, light will enter the white marking material.
[0092]Since the white marking material scatters light at a variety of angles, these rays of scattered light then travel directly through the colored marking material because the colored marking material and white marking material have similar indices of refraction. Due to the many angles of incidence on the colored marking material-air boundary, many rays will not internally reflect, but will be externally refracted and seen by the viewer.
[0093]FIG. 11 is a table providing a summary of the various optical paths through an optical waveguide, as illustrated in FIGS. 8 and 9. More specially, the optical path is defined as light entering the optical waveguide on the left from an illumination source (LED). The light is then refracted at an air-optical waveguide interface and internally reflected at multiple optical waveguide-air interfaces for all angles. The light is partially externally refracted at the optical waveguide-marking material interface for some angles.
[0094]The externally refracted light travels through the marking material, and then, since marking material has a rough surface, creating many angles of incidence at the marking material-air boundary, much of the light exits the marking material and travels towards the viewer.
[0095]As shown in FIG. 11, on the far left, light enters the optical waveguide (for example, from an LED) with angles of incidence θi ranging from 0 to 90 degrees. The shown refracted angles θr1 are computed on the basis of Snell's law. The rays of light along the θr1 paths strike an optical waveguide-air boundary such that for all possible θr1, the light will be totally internally reflected within the optical waveguide (indicated by #NUM! in dashed boxes 63). The value, #NUM!, indicates that there is no solution for a refracted ray.
[0096]After bouncing back and forth within the optical waveguide, the light rays will strike the optical waveguide-marking material boundary at the same angles as it had struck the optical waveguide-air boundary.
[0097]However, since the difference in index of refraction between air (1.0) and the marking material (for example, 1.4) and depending on the angle of incidence, some of the light is externally refracted into the marking material instead of being internally reflected within the optical waveguide.
[0098]The cells within the dashed boxes 64 in FIG. 11 identify the light rays that will be completely internally reflected at the optical waveguide-air interface and partially externally refracted at the optical waveguide-marking material interface. Thus, light will enter the marking material.
[0099]Since the marking material has a rough surface, it produces a variety of angles of incidence. Due to the many angles of incidence on the marking material-air boundary, many rays will not internally reflect, but will be externally refracted and seen by the viewer.
[0100]In other words, if the top surface of the marking material is smooth, all of the light entering the marking material will be totally internally reflected at the marking material-air boundary. However, light will escape the marking material is if the angle of interface is modified due to surface roughness.
[0101]As illustrated in FIG. 11, the angle of incidence of the light rays (the cells within the dashed box 65) striking the marking material-air boundary quantify the effect of surface roughness.
[0102]Thus, the surface roughness causes some of the light to be externally refracted at the marking material-air boundary and exit the marking material towards the viewer.
[0103]These cells of dashed box 65 can be traced across the table, starting at a certain angle of incidence from the LED, internally reflected where there is no marking material, refracting into the marking material, and then refracting out of the marking material due to the surface roughness.
[0104]It is noted that surface roughness of the printed marking material can be enhanced through halftoning.
[0105]FIG. 12 illustrates an optical waveguide display system, wherein an optical waveguide 10, when illuminated by a light source 20, displays printed on images 110, 1120, and 113. Since the images 110, 1120, and 113 are printed onto the optical waveguide 10, the images can be different colors and not rely upon the color of the light source 20 to define their color.
[0106]Moreover, the images 110, 1120, and 113 may comprise the dual marking material construction of FIGS. 6 and 7 or the marking material with rough surface construction of FIGS. 8 and 9.
[0107]FIG. 13 illustrates an optical waveguide display system, wherein an optical waveguide 10, when illuminated by a light source 20, displays images printed on both sides of the optical waveguide 10. Since the images are printed onto both sides of the optical waveguide 10, the images are constructed differently depending upon the surface side of the optical waveguide 10 with respect to a viewing side 30.
[0108]As illustrated in FIG. 13, on a front surface of the optical waveguide 10 (the viewing side 30), the image is constructed in the same manner as illustrated in FIG. 6, wherein a white marking material 40 is printed onto the front surface of the optical waveguide 10, followed by the printing of a marking material 50.
[0109]When the image on the front surface of the optical waveguide 10 is illuminated by a light source 20, the printed image (40 and 50) is viewed by the viewer 30.
[0110]As further illustrated in FIG. 13, on a back surface of the optical waveguide 10, the image is constructed in a different manner, wherein a marking material 55 is printed onto the back surface of the optical waveguide 10, followed by the printing of a white marking material 45.
[0111]When the image on the back surface of the optical waveguide 10 is illuminated by a light source 20, the printed image (45 and 55) is viewed by the viewer 30.
[0112]It is noted that the thickness of the optical waveguide 10 can be such to present the images at different depths, thereby making one image to appear to be floating in front of the other image.
[0113]FIG. 14 illustrates an optical waveguide display system, wherein an optical waveguide 10, when illuminated by a light source 20, displays images printed on both sides of the optical waveguide 10 and can be observed from both viewing sides (30 and 31). In this embodiment, the images are printed onto both sides of the optical waveguide 10 using the same construction.
[0114]As illustrated in FIG. 14, on a front surface of the optical waveguide 10 (the viewing side 30), the image is constructed of a white marking material 40 that is printed onto the front surface of the optical waveguide 10.
[0115]When the image on the front surface of the optical waveguide 10 is illuminated by a light source 20, the printed image (40) on the front surface of the optical waveguide 10 is viewed by the viewer 30 and viewer 31.
[0116]As further illustrated in FIG. 14, on a back surface of the optical waveguide 10, the image is also constructed of a white marking material 45 that is printed onto the back surface of the optical waveguide 10.
[0117]When the image on the back surface of the optical waveguide 10 is illuminated by a light source 20, the printed image (45) on the back surface of the optical waveguide 10 is viewed by the viewer 30 and viewer 31.
[0118]It is noted that the thickness of the optical waveguide 10 can be such to present the images at different depths, thereby making one image to appear to be floating in front of the other image.
[0119]FIG. 15 illustrates an optical waveguide display system, wherein an optical waveguide 10, when illuminated by a light source 20, displays images printed on both sides of the optical waveguide 10 and only one viewing side can view both images. In this embodiment, the images are printed onto both sides of the optical waveguide 10 using different constructions.
[0120]As illustrated in FIG. 15, on a front surface of the optical waveguide 10 (the viewing side 30), the image is constructed in the same manner as illustrated in FIG. 6, wherein a white marking material 40 is printed onto the front surface of the optical waveguide 10, followed by the printing of a marking material 50.
[0121]When the image on the front surface of the optical waveguide 10 is illuminated by a light source 20, the printed image (40 and 50) can only be viewed by the viewer 30.
[0122]As further illustrated in FIG. 15, on a back surface of the optical waveguide 10, the image is also constructed of a white marking material 45 that is printed onto the back surface of the optical waveguide 10.
[0123]When the image on the back surface of the optical waveguide 10 is illuminated by a light source 20, the printed image (45) on the back surface of the optical waveguide 10 can be viewed by the viewer 30 and viewer 31.
[0124]In other words, the embodiment of FIG. 15 enables both images to be viewed by viewer 30, but viewer 31 cannot view the image on the front surface of the optical waveguide 10.
[0125]Moreover, as illustrated in FIG. 15, the image printed on the front surface of the optical waveguide 10 can be a color image with a white background and it is only viewable as a color image by viewer 30. On the other hand, the image printed on the back surface of the optical waveguide 10 is a monochrome image, which is viewable by viewer 30 and viewer 31.
[0126]It is noted that the thickness of the optical waveguide 10 can be such to present the images at different depths, thereby making one image to appear to be floating in front of the other image.
[0127]FIG. 16 illustrates an optical waveguide display system, wherein an optical waveguide 10, when illuminated by a light source 20, displays images printed on both sides of the optical waveguide 10. In this embodiment, the images are printed onto both sides of the optical waveguide 10 using different constructions.
[0128]As illustrated in FIG. 16, on a front surface of the optical waveguide 10 (the viewing side 30), the image is constructed, wherein a marking material 50 is printed onto the front surface of the optical waveguide 10.
[0129]As further illustrated in FIG. 16, on a back surface of the optical waveguide 10, the image is also constructed of a white marking material 45 that is printed onto the back surface of the optical waveguide 10.
[0130]The image on the front surface of the optical waveguide 10 is not viewable alone. The back side image is viewable through the panel by the viewer 30.
[0131]As illustrated in FIG. 16, the front image may be a color image without a white background. The color image is typically not viewable alone because there is no scattering. The back side image is a monochrome image created with white marking material 45, which is viewable by viewer 30 and viewer 31.
[0132]When the front image and the back image are assembled together, the front side image becomes visible in direction of viewer 30 when the backside image (white marking material 45) provides the scattering light.
[0133]When the image on the back surface of the optical waveguide 10 is illuminated by a light source 20, the printed image (45) on the back surface of the optical waveguide 10 can be viewed by the viewer 30 and viewer 31.
[0134]It is noted that the backside image should be viewable through the optical waveguide 10. The front side image can be a scattering viewable image or transparent non-viewable image.
[0135]The front side image may be sparse, such that there is plenty of transparent viewing area for the back side image.
[0136]It is noted that the thickness of the optical waveguide 10 can be such to present the images at different depths, thereby making one image to appear to be floating in front of the other image.
[0137]FIG. 17 illustrates a display device for displaying three-dimensional images. As illustrated in FIG. 17, a plurality of optical waveguides (10, 12, and 14). Each optical waveguide has printed thereon images on both sides of the optical waveguide in the same manner as the dual sided images are constructed in the embodiment of FIG. 13.
[0138]More specifically, on a front surface of each optical waveguide (the viewing side 30), a white marking material 40 is printed onto the front surface of the optical waveguide, followed by the printing of a marking material 50.
[0139]When the image on the front surface of the optical waveguide is illuminated by a light source 20, the printed image (40 and 50) is viewed by the viewer 30.
[0140]As further illustrated in FIG. 17, on a back surface of each optical waveguide, a marking material 55 is printed onto the back surface of the optical waveguide, followed by the printing of a white marking material 45.
[0141]When the image on the back surface of the optical waveguide is illuminated by a light source 20, the printed image (45 and 55) is viewed by the viewer 30.
[0142]FIG. 18 illustrates an optical waveguide capable of providing a white background for an image printed thereon. As illustrated in FIG. 18, a white marking material 400 is printed over an entire image area. Thereafter, a marking material 50 is printed on the white marking material 400.
[0143]It is noted that the white marking material 400 has a varied light scattering particle volumetric density, wherein the light scattering particle volumetric density increases proportionally along the surface of the optical waveguide as a distance away from a light source interface of the optical waveguide increases.
[0144]If the light scattering particle volumetric density did not vary proportionally as the distance from the light source interface of the optical waveguide increases most of the light would escape the optical waveguide near the light source interface and there would be enough light to properly illuminate an image in the middle of the optical waveguide.
[0145]The light source interface is the interface (surface) of the optical waveguide that receives incident light from a light source.
[0146]An image is printed on the white marking material 400 using marking material 50.
[0147]FIG. 19 illustrates an optical waveguide wherein an image is initially printed on a transparent medium 70, and the transparent medium 70 is attached to the optical waveguide 10. As illustrated in FIG. 19, a marking material 50 with a rough surface 55 is printed on the transparent medium 70.
[0148]It is noted that the transparent medium 70 should be attached to the optical waveguide 10 so that there are no air gaps between the transparent medium 70 and the optical waveguide 10.
[0149]For example, the transparent medium 70 may be bonded to the optical waveguide using a curable agent that can be rolled to remove the air gaps before curing.
[0150]It is noted that the transparent medium 70 may be an optical waveguide having an index of refraction substantially equal to the index of refraction of the optical waveguide 10.
[0151]FIG. 20 illustrates an optical waveguide wherein an image is initially printed on a transparent medium 70, and the transparent medium 70 is attached to the optical waveguide 10. As illustrated in FIG. 20, a white marking material 40 is printed on the transparent medium 70, followed by the printing of a marking material 50.
[0152]It is noted that the transparent medium 70 should be attached to the optical waveguide 10 so that there are no air gaps between the transparent medium 70 and the optical waveguide 10.
[0153]For example, the transparent medium 70 may be bonded to the optical waveguide using a curable agent that can be rolled to remove the air gaps before curing.
[0154]It is noted that the transparent medium 70 may be an optical waveguide having an index of refraction substantially equal to the index of refraction of the optical waveguide 10.
[0155]FIG. 21 illustrates an optical waveguide display system, wherein an optical waveguide 10, when illuminated by a light source 20, displays images printed on both sides of the optical waveguide 10. Since the images are printed onto both sides of the optical waveguide 10, the images are constructed differently depending upon the surface side of the optical waveguide 10 with respect to a viewing side 30.
[0156]As illustrated in FIG. 21, on a front surface of the optical waveguide 10 (the viewing side 30), the image is constructed in the same manner as illustrated in FIG. 8, wherein a marking material 50 with a rough surface 55 is printed onto the front surface of the optical waveguide 10.
[0157]When the image on the front surface of the optical waveguide 10 is illuminated by a light source 20, the printed image (50 with rough surface 55) is viewed by the viewer 30.
[0158]As further illustrated in FIG. 21, on a back surface of the optical waveguide 10, the image is constructed in a different manner, wherein a marking material 55 is printed onto the back surface of the optical waveguide 10, followed by the printing of a white marking material 45.
[0159]When the image on the back surface of the optical waveguide 10 is illuminated by a light source 20, the printed image (45 and 55) is viewed by the viewer 30.
[0160]It is noted that the thickness of the optical waveguide 10 can be such to present the images at different depths, thereby making one image to appear to be floating in front of the other image.
[0161]FIG. 22 illustrates an optical waveguide 10 capable of providing a white background for an image area 35. As illustrated in FIG. 22, a white marking material 40 is printed over the image area 35 to create a paper-like uniform background.
[0162]It is noted that the white marking material 40 may be printed over the entire image area 35. Thereafter, a marking material 57 is printed on the white marking material 40.
[0163]It is noted that the marking material 57 may produce a black image, thereby providing a black/white image for displaying (illuminating) on the optical waveguide 10.
[0164]It is noted that the white marking material 40 may have a varied light scattering particle volumetric density, wherein the light scattering particle volumetric density increases proportionally along the surface of the optical waveguide as a distance away from a light source interface of the optical waveguide increases.
[0165]The light source interface is the interface (surface) of the optical waveguide that receives incident light from a light source.
[0166]With respect to FIG. 22, the light, which is trapped (internally reflected) in the optical waveguide 10, enters the white marking material 40 and gets scattered uniformly by the white marking material 40. The scattered light is then absorbed by the marking material 57, which may produce black or color, in an image-wise fashion. In essence, the image is created by absorption of light through the marking material 57.
[0167]FIG. 23 illustrates an optical waveguide 10 capable of providing a black/white image within an image area 35. As illustrated in FIG. 23, a white marking material 40 is printed, in an image-wise fashion, within the image area 35.
[0168]With respect to FIG. 23, the light, which is trapped (internally reflected) in the optical waveguide 10, enters the white marking material 40 and gets scattered, in an image-wise fashion, by the white marking material 40. A portion of the scattered light exits the white marking material 40 and is observed by a viewer. In essence, the image is created by scattering of light through scattering particles in the white marking material 40.
[0169]It is noted that shading within the image may be provided by the modulation of the amplitude/intensity of the scattering according the intended image.
[0170]For example, by controlling an amount of white markin