Source: http://www.google.com/patents/US7949213?dq=patent:6161142
Timestamp: 2014-09-23 08:52:29
Document Index: 583693175

Matched Legal Cases: ['Application No. 08153690', 'Application No. 08075318', 'Application No. 2007', 'Application No. 200580030964', 'Application No. 05', 'Application No. 08', 'Application No. 2007', 'Application No. 2007115881']

Patent US7949213 - Light illumination of displays with front light guide and coupling elements - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign in<nobr>Advanced Patent Search</nobr>PatentsIn various embodiments described herein, a display device includes a front illumination apparatus that comprises a first light guide disposed forward of an array of display elements, such as an array of interferometric modulators, to distribute light across the array of display elements. The light guide...http://www.google.com/patents/US7949213?utm_source=gb-gplus-sharePatent US7949213 - Light illumination of displays with front light guide and coupling elementsAdvanced Patent SearchPublication numberUS7949213 B2Publication typeGrantApplication numberUS 11/952,872Publication dateMay 24, 2011Filing dateDec 7, 2007Priority dateDec 7, 2007Also published asCN101889225A, CN101889225B, EP2068181A1, EP2068182A1, EP2068182B1, US20090147535, US20110182086, WO2009073555A1Publication number11952872, 952872, US 7949213 B2, US 7949213B2, US-B2-7949213, US7949213 B2, US7949213B2InventorsMarek Mienko, Gang Xu, Ion Bita, Russell Wayne Gruhlke, Alberto Emerico BrewerOriginal AssigneeQualcomm Mems Technologies, Inc.Export CitationBiBTeX, EndNote, RefManPatent Citations (111), Non-Patent Citations (44), Referenced by (4), Classifications (24), Legal Events (3) External Links: USPTO, USPTO Assignment, EspacenetLight illumination of displays with front light guide and coupling elementsUS 7949213 B2Abstract In various embodiments described herein, a display device includes a front illumination apparatus that comprises a first light guide disposed forward of an array of display elements, such as an array of interferometric modulators, to distribute light across the array of display elements. The light guide panel is edge illuminated by a light source positioned behind the array display elements. The light from such a light source is coupled to a second light guide disposed behind the array of display elements and positioned laterally with respect to the light source. The light in the second light guide is coupled into the first light guide using a small optical coupling element such as a turning mirror. In some embodiments the second light guide may comprise the backplate of the display device.
a reflective spatial light modulator included in a pixel of a display;
a light source rearward of said reflective spatial light modulator;
a first light guide forward of said reflective spatial light modulator, said first light guide having forward and rearward surfaces;
a second light guide rearward of said reflective spatial light modulator such that light from said light source propagates therein; and
a turning mirror disposed to receive light from an edge of the second light guide that is distal to the light source and direct said light into said first light guide, such that said light is total internally reflected from the forward and rearward surfaces of the first light guide so as to be guided along the length of the first light guide,
wherein said first light guide is configured to direct said light coupled therein to said reflective spatial light modulator.
2. The display device of claim 1, wherein said reflective spatial light modulator comprises an electromechanical system.
3. The display device of claim 1, wherein said reflective spatial light modulator comprises a plurality of interferometric modulators.
4. The display device of claim 1, wherein said reflective spatial light modulator comprises a substrate on which a plurality of modulating elements is formed.
5. The display device of claim 1, wherein said light source comprises a light emitting diode.
6. The display device of claim 1, wherein said light source comprises a light bar having two ends, two sides, and a top and bottom, said top and bottom and sides disposed between said ends, wherein light injected into one end of the light bar propagates toward the other end and is deflected so as to exit a side of said light bar into said second light guide, said ends being small in area compared to said sides.
7. The display device of claim 4, wherein said first light guide is said substrate on which said plurality of modulating elements are formed.
8. The display device of claim 4, wherein said first light guide comprises a sheet, plate, film, or film stack or combination thereof disposed forward said substrate.
9. The display device of claim 8, further comprising an isolation layer between said first light guide and said substrate.
10. The display device of claim 1, further comprising turning features disposed on or in said first light guide to turn said light propagating therein onto said reflective spatial light modulator.
11. The display device of claim 10, wherein said turning features comprise a reflective, refractive, holographic or diffractive optical element.
12. The display device of claim 1, wherein said second light guide is a backplate for said reflective spatial light modulator.
13. The display device of claim 1, wherein said second light guide comprises an existing backlight for said reflective spatial light modulator.
14. The display device of claim 4, wherein said second light guide is said substrate on which said plurality of modulating elements are formed.
15. The display device of claim 14, wherein said second light guide comprises a sheet, plate, film, film stack, or combination thereof.
16. The display device of claim 4, further comprising an isolation layer disposed between said first light guide and said substrate.
17. The display device of claim 1, wherein said turning mirror comprises a curved reflective surface.
18. The display device of claim 17, wherein said curved reflective surface is elliptical.
19. The display device of claim 18, wherein said elliptical surface has foci proximal to ends of said first light guide and said second light guide such that said light from said light source passes though said second light guide to said turning mirror and into said first light guide.
20. The display device of claim 1, wherein said turning mirror comprises a plurality of planar mirror surfaces oriented at an angle with respect to each other.
21. The display device of claim 20, wherein said angle is between about 90 and 120 degrees.
22. The display device of claim 20, wherein said angle is about 90 degrees.
23. The display device of claim 20, wherein said angle is about 120 degrees.
24. The display device of claim 1, wherein said turning mirror comprises a metalized surface.
25. The display device of claim 1, wherein said turning mirror comprises a reflective dielectric stack.
26. The display device of claim 1, further comprising:
a processor that is configured to communicate with said spatial light modulator, said processor being configured to process image data; and
27. The display device of claim 26, further comprising a driver circuit configured to send at least one signal to said spatial light modulator.
28. The display device of claim 27, further comprising a controller configured to send at least a portion of the image data to said driver circuit.
29. The display device of claim 26, further comprising an image source module configured to send said image data to said processor.
30. The display device of claim 29, wherein the image source module comprises at least one of a receiver, transceiver, and transmitter.
31. The display device of claim 26, further comprising an input device configured to receive input data and to communicate said input data to said processor.
32. A display device comprising:
a means for reflectively modulating light for forming part of an image;
a means for illuminating disposed rearward of said reflectively light modulating means;
a first means for guiding light forward of said reflectively light modulating means, said first means for guiding light having forward and rearward surfaces;
a second means for guiding light rearward of said reflectively light modulating means such that light from said light illuminating means propagates therein; and
a turning mirror disposed to receive light from an edge of said second light guiding means that is distal to said illuminating means and direct said light into said first light guiding means, such that said light is total internally reflected from the forward and rearward surfaces of the first means for guiding light so as to be guided along the length of the first means for guiding light,
wherein said first light guiding means is configured to direct said light coupled therein to said reflectively light modulating means.
33. A method of manufacturing a display device, the method comprising:
providing a reflective spatial light modulator included in a pixel of a display;
disposing a light source rearward of said reflective spatial light modulator;
disposing a first light guide forward of said reflective spatial light modulator, said first light guide having forward and rearward surfaces;
disposing a second light guide rearward of said reflective spatial light modulator such that light from said light source propagates therein; and
disposing a turning mirror to receive light from an edge of the second light guide that is distal to the light source and direct said light into said first light guide, such that said light is total internally reflected from the forward and rearward surfaces of the first light guide so as to be guided along the length of the first light guide.
34. The display device of claim 1, wherein said light source comprises a light bar having two ends and a plurality of sides disposed between said ends, said light source further comprising a light emitter disposed with respect to said light bar to injected light into one end of the light bar, said light propagating toward the other end and being deflected so as to exit a side of said light bar into said second light guide. Description
The present invention relates to microelectromechanical systems (MEMS), and more particularly to displays comprising MEMS.
SUMMARY Various embodiments described herein comprise light guides for distributing light across an array of display elements. The light guide may include surface relief features to turn light propagating in a light guide onto the array of display elements. The surface relief features may comprise facets that reflect light. The light guide may be illuminated by a light source placed behind the array of display elements.
In one embodiment of this invention, a display device comprises a reflective spatial light modulator, a light source rearward of the reflective spatial light modulator, a first light guide forward of the reflective spatial light modulator and a turning mirror disposed to receive light from the light source and direct the light into said first light guide. The first light guide is configured to direct the light coupled therein to the reflective spatial light modulator.
In another embodiment of this invention, a display device comprises a reflective spatial light modulator, a light source, a light bar disposed to receive light from the light source, a light guide forward of said reflective spatial light modulator and an optical coupler disposed to receive light from the light bar and direct said light into said light guide. The light guide is configured to direct the light coupled therein to the reflective spatial light modulator.
In one embodiment, a display device comprises a means for reflectively modulating light. The display device further comprises a means for illuminating; a means for receiving light from the illuminating means; a means for guiding light disposed forward of the reflectively light modulating means; and a means for coupling light disposed to receive light from the light receiving means and directing the light into the light guiding means. The light guiding means is configured to direct the light coupled therein to the reflectively light modulating means.
In another embodiment, a display device comprises a means for reflectively modulating light; a means for illuminating disposed rearward of the reflectively light modulating means; a first means for guiding light forward of the reflectively light modulating means; and a means for reflecting light disposed to receive light from the illuminating means and direct the light into the first light guiding means. The first light guiding means is configured to direct the light coupled therein to the reflectively light modulating means.
In a certain embodiment, a method of manufacturing a display device comprises providing a reflective spatial light modulator. The method further comprises disposing a light source rearward of the reflective spatial light modulator, disposing a first light guide forward of the reflective spatial light modulator and disposing a turning mirror to receive light from the light source and direct the light into the first light guide.
In another embodiment, a method of manufacturing a display device comprises providing a reflective spatial light modulator. The method further comprises providing a light source, disposing a light bar to receive light from the light source and disposing a light guide forward of the reflective spatial light modulator. The method also comprises disposing an optical coupler to receive light from the light bar and direct the light into the light guide.
In another embodiment, a display device comprises a means for reflectively modulating light; a means for illuminating disposed forward of the reflectively light modulating means; a first means for guiding light forward of the reflectively light modulating means; and a means for reflecting light disposed to receive light from the illuminating means and direct the light into the first light guiding means. The first light guiding means is configured to direct the light coupled therein to the reflectively light modulating means.
In one embodiment, a display device comprises a reflective spatial light modulator; a light source forward of the reflective spatial light modulator; a first light guide forward of the reflective spatial light modulator; and a turning mirror disposed to receive light from the light source and direct the light into the first light guide. The first light guide is configured to direct said light coupled therein to the reflective spatial light modulator.
In a certain embodiment, a method of manufacturing a display device comprises providing a reflective spatial light modulator. The method further comprises disposing a light source forward of the reflective spatial light modulator, disposing a first light guide forward of the reflective spatial light modulator and disposing a turning mirror to receive light from the light source and direct the light into the first light guide.
BRIEF DESCRIPTION OF THE DRAWINGS Example embodiments disclosed herein are illustrated in the accompanying schematic drawings, which are for illustrative purposes only.
FIG. 8 is a top view of a display device comprising a light source, a light bar reflector and a light guide panel that can illuminate an array of interferometric modulators.
FIG. 9 is a cross section of a portion of an embodiment of a display device comprising of an elliptical turning mirror coupling light from the light source into the light guide panel.
FIG. 10 is a perspective view of a curved turning mirror.
FIG. 11 is a cross section of a portion of an embodiment of a display device comprising of a turning mirror having two planar reflective surfaces angled with respect to each other.
FIG. 12 is a cross section of a portion of another embodiment of a display device comprising of a turning mirror having three planar reflective surfaces angled with respect to each other.
FIG. 13 is a cross section of a portion of another alternative embodiment of a display device wherein an isolation layer is disposed between the front light guide and the array of interferometric modulators.
FIG. 14 is a cross section of a portion of an embodiment of a display device wherein the substrate on which the array of interferometric modulators are formed is used as a light guide.
FIG. 15 is a perspective view of an embodiment of a display device comprising a light bar disposed on the light guide panel and a turning mirror configured to couple light from the light bar into the light guide panel.
DETAILED DESCRIPTION OF CERTAIN PREFERRED EMBODIMENTS The following detailed description is directed to certain specific embodiments of the invention. However, the invention can be embodied in a multitude of different ways. In this description, reference is made to the drawings wherein like parts are designated with like numerals throughout. As will be apparent from the following description, the embodiments may be implemented in any device that is configured to display an image, whether in motion (e.g., video) or stationary (e.g., still image), and whether textual or pictorial. More particularly, it is contemplated that the embodiments may be implemented in or associated with a variety of electronic devices such as, but not limited to, mobile telephones, wireless devices, personal data assistants (PDAs), hand-held or portable computers, GPS receivers/navigators, cameras, MP3 players, camcorders, game consoles, wrist watches, clocks, calculators, television monitors, flat panel displays, computer monitors, auto displays (e.g., odometer display, etc.), cockpit controls and/or displays, display of camera views (e.g., display of a rear view camera in a vehicle), electronic photographs, electronic billboards or signs, projectors, architectural structures, packaging, and aesthetic structures (e.g., display of images on a piece of jewelry). MEMS devices of similar structure to those described herein can also be used in non-display applications such as in electronic switching devices.
In various embodiments described herein, a display device includes a front illumination apparatus that comprises a light guide disposed forward of an array of display elements, such as an array of interferometric modulators, to distribute light across the array of display elements. For example, a light guide panel may comprise a transparent sheet or plate and a turning film thereon. The light guide panel is edge illuminated by a light source and at least a portion of this light is delivered uniformly across the array of display elements. For many portable display applications, however, it is useful for the display to be compact. Accordingly, in various embodiments described herein, the light source is positioned directly behind the array display elements to reduce the footprint of display device. In certain embodiments, for example, two light guide panels may be used. A first light guide is disposed forward to the display elements and a second light guide is disposed rearward to the display elements. The second light guide is edge illuminated by the light source. The first guide comprises the substrate supporting the array of display elements and a turning film formed thereon. A small optical coupling element such as, for example, a turning mirror is used to couple light from the second light guide to the first light guide. The second light guide may comprise the substrate supporting the display elements or the backplate of the display device in certain embodiments. In some embodiments, the first light guide comprises the substrate and the second light guide comprises the backplate. Such designs may be useful in addressing the size or form factor restrictions. The second light guide is thin as compared to the substrate and the array of display elements. As a consequence, the overall thickness of the entire display is only slightly increased beyond that of the display elements themselves which are formed on a substrate. The footprint however is reduced by locating light sources behind the display element rather than on the side thereof.
FIGS. 4, 5A, and 5B illustrate one possible actuation protocol for creating a display frame on the 3�3 array of FIG. 2. FIG. 4 illustrates a possible set of column and row voltage levels that may be used for pixels exhibiting the hysteresis curves of FIG. 3. In the FIG. 4 embodiment, actuating a pixel involves setting the appropriate column to −Vbias, and the appropriate row to +ΔV, which may correspond to −5 volts and +5 volts, respectively Relaxing the pixel is accomplished by setting the appropriate column to +Vbias, and the appropriate row to the same +ΔV, producing a zero volt potential difference across the pixel. In those rows where the row voltage is held at zero volts, the pixels are stable in whatever state they were originally in, regardless of whether the column is at +Vbias, or −Vbias. As is also illustrated in FIG. 4, it will be appreciated that voltages of opposite polarity than those described above can be used, e.g., actuating a pixel can involve setting the appropriate column to +Vbias, and the appropriate row to −ΔV. In this embodiment, releasing the pixel is accomplished by setting the appropriate column to −Vbias, and the appropriate row to the same −ΔV, producing a zero volt potential difference across the pixel.
The details of the structure of interferometric modulators that operate in accordance with the principles set forth above may vary widely. For example, FIGS. 7A-7E illustrate five different embodiments of the movable reflective layer 14 and it's supporting structures. FIG. 7A is a cross section of the embodiment of FIG. 1, where a strip of metal material 14 is deposited on orthogonally extending supports 18. In FIG. 7B, the moveable reflective layer 14 is attached to supports at the corners only, on tethers 32. In FIG. 7C, the moveable reflective layer 14 is suspended from a deformable layer 34, which may comprise a flexible metal. The deformable layer 34 connects, directly or indirectly, to the substrate 20 around the perimeter of the deformable layer 34. These connections are herein referred to as support posts. The embodiment illustrated in FIG. 7D has support post plugs 42 upon which the deformable layer 34 rests. The movable reflective layer 14 remains suspended over the gap, as in FIGS. 7A-7C, but the deformable layer 34 does not form the support posts by filling holes between the deformable layer 34 and the optical stack 16. Rather, the support posts are formed of a planarization material, which is used to form support post plugs 42. The embodiment illustrated in FIG. 7E is based on the embodiment shown in FIG. 7D, but may also be adapted to work with any of the embodiments illustrated in FIGS. 7A-7C, as well as additional embodiments not shown. In the embodiment shown in FIG. 7E, an extra layer of metal or other conductive material has been used to form a bus structure 44. This allows signal routing along the back of the interferometric modulators, eliminating a number of electrodes that may otherwise have had to be formed on the substrate 20.
As described above, the interferometric modulators are reflective display elements and can rely on ambient lighting in daylight or well-lit environments. In addition, an internal source of illumination can be provided for illuminating these reflective display elements in dark ambient environments. The illumination for reflective displays may be provided by a front illuminator. FIG. 8 shows the top view of a portion of a display device 80 comprising an illumination apparatus configured to provide front illumination. The display device 80 comprises a light source 82, a light bar 81 and a light guide panel 83. The light source 82 in this particular embodiment comprises an LED. The light bar 81 is disposed with respect to the light source 82 to receive light therefrom. Reflective sections 85 a and 85 b are disposed with respect to the side and end of the light bar 81. Reflectors may also be included above and/or below the light bar 81. The light bar 81 comprises substantially optically transmissive material that supports propagation of light along the length thereof. Light emitted from the light emitter 82 propagates into the light bar 81 and is guided therein, for example, via total internal reflection at sidewalls of the light bar, which form interfaces with air or some other surrounding medium. The light bar 81 includes turning microstructure 84 on one side that is opposite the light guide panel 83. The turning microstructure 84 is configured to turn a substantial portion of the light incident on that side of the light bar 81 and to direct a portion of this light out of the light bar 81 into the light guide panel 83. In certain embodiments, the illumination apparatus may further comprise a coupling optic (not shown) between the light bar 81 and the light guide panel 83. For example, the coupling optic may collimate light propagating from the light bar 81. Other configurations are also possible.
The light guide panel 83 is disposed with respect to the light bar 81 so as to receive light that has been turned by the turning microstructure 84 and directed out of the light bar 81. In certain embodiments, for example, the light guide panel 83 comprises a sheet or plate having a prismatic film thereon that reflects light from the light bar 81 onto a plurality of display elements (not shown) beneath the light guide panel in FIG. 8. The plurality of display elements may comprise, for example, a plurality of spatial light modulators (e.g. interferometric modulators, liquid crystal elements, etc.).
To reduce the footprint of display device, in certain embodiments the light bar 81 which is disposed adjacent to one edge of the light guide panel 83 in FIG. 8 may be replaced with another smaller optical coupling element such as, for example, a turning mirror. Removing the light bar 81 from the side of the light guide panel 83 reduces the footprint by reducing the dimension of the display device in the X-Y plane. Moreover, the light bar 81 need not be included thereby reducing device complexity and possible cost. Such a configuration may also allow the light source 82 to be positioned behind the plurality of display elements possibly further reducing the footprint. Such designs may be useful in addressing the size or form factor restrictions or other considerations. Various approaches described herein may therefore use a light source behind the display elements and a turning mirror to front illuminate a reflective display element.
FIG. 9 illustrates a cross section of a portion of one embodiment of a display device 90 wherein the light bar 81 of FIG. 8 is replaced with an optional coupling element. The display device 90 in FIG. 9 comprises a reflective display comprising a plurality of reflective elements 96 such as reflective spatial light modulators. In the embodiment shown in FIG. 9, the reflective display elements 96 comprise interferometric modulators, although other types of display elements may be used in the device. Other examples of display elements include MEMS and liquid crystal structures. The display elements 96 may be formed on an optically transmissive substrate 95. This substrate 95 may provide structural support during and after fabrication of the display elements 96 thereon. The substrate 95 may be substantially transparent such that a viewer can see the display elements 96 through the substrate. In some embodiments the substrate 95 may comprise glass or plastic although other materials may also be used.
In the embodiment shown in FIG. 9, the substrate 95 has a turning film 94 formed thereon. The turning film 94 may comprise, for example, a prismatic film that includes turning features formed therein. In some embodiments, the turning film 94 may comprise a plastic film laminated onto the substrate 95. Adhesive may be used to affix the turning film 94 to the substrate 95. Pressure sensitive adhesive may be used. The adhesive may provide index matching in some embodiments as well. Other methods of attaching the turning film 94 to the substrate 95 may be used. In certain embodiments the turning film 94 can be a multilayer stack instead of a single layer. In case of a multilayer stack, the refractive indices of the different layers may be close so that light is transmitted through the various layers without being substantially reflected or refracted. The film or films may be rigid or flexible. In certain embodiments the film or films have an index of refraction substantially similar to that of the substrate 95.
The substrate 95 and the turning film 94 together form a first light guiding element 97 that is located above the interferometric modulators 96 of the display device 90. In certain embodiments wherein the turning film 94 is attached to the substrate 95 with index matching adhesive, the first light guiding element 97 is increased in thickness. Some advantages of a thicker first light guiding element 97 are the relative ease in achieving uniformity in brightness and increasing the efficiency of the light coupled into the first light guiding element 97.
In some other embodiments, the turning film 94 may be joined to the substrate 95 by an adhesive layer that has substantially lower refractive index than the refractive index of the turning film 94. Other layers or film such as optical isolation layer, diffuser layer or color filter layer may be disposed between the adhesive layer and the substrate. Light is guided in the turning film 94 by total internal reflection at the interface between the turning film and the adhesive layer. In such embodiments, the first light guiding element is formed by the turning film 94 only.
The plurality of turning features in the turning film 94 redirect light normally guided in the light guide 97 such that the light is directed out of the light guide towards the display elements 96. The direction of the turned light forms an angle smaller than 45 degrees from the normal to the surface of the display elements. In various embodiments, light is redirected through the thickness of the first light guide 97 substantially normal to the light guide and the array of display elements 96. Accordingly, such light is no longer totally internally reflected at the lower sidewall of the light guide and exits therethrough. Likewise, the light is transmitted to the interferometric modulators preferably at normal incidence or close thereto.
In some embodiments, the turning features may comprise a plurality of microprisms extending along the length of the first light guide 97. The microprisms may be configured to receive light propagating along the length of the turning film 94 and turn the light through a large angle, usually between about 70-90� with a plurality of grazing incidence reflections. The prismatic microstructures may comprise two or more turning facets angled with respect to one another for reflecting the light at the air/facet interface via total internal reflection and causing the light to be turned toward the array of display elements 96 at near normal incidence or close thereto.
In an alternative embodiment, the turning features may comprise one or more diffractive optical elements or hologram (e.g., volume or surface holograms or grating) configured to receive light normally guided in the first light guide 97 and turn the light such that the light is redirected towards the display elements 96. In certain embodiments, the propagation direction of the turned light forms an angle smaller than 45 degrees from the normal to the display elements 96.
A light source 92 is disposed rearward of the interferometric modulators 96 on a first side (side 1) of the display device 90. A second light guide 98 is disposed with respect to the light source 92 to receive light injected therein by the light source 92. In certain embodiments, the second light guide 98 may comprise the backplate of the display device. In certain other embodiments, the second light guide 98 may comprise an existing backlight in the display device 90. This light source 92 could be a single LED or an array of LEDs extending along an edge of the second light guide 98. In certain embodiments, for example, the light source 92 may comprise a plurality of LEDs parallel to the x-axis that emit light parallel to the y axis (e.g., in the negative y direction) to illuminate the second light guide 98 uniformly. In other embodiments, the light source 92 may comprise an LED emitting in a direction parallel to the x-axis (e.g. in the negative x direction) coupled to a light bar which has turning features that turn a substantial amount of light propagating parallel to the x axis in a direction parallel to the y axis (e.g. in the negative y direction). Other types of emitters may also be used. Additionally, in some embodiments optical lens or other optical components may be used to couple the light from the light source 92 into the second light 98. Optical features may also be included to expand the width of or diverge the beam of light from the light source 92 propagating in the second light guide 98. Such features may be on the input end of the light guide near the light source 92 in some embodiments.
Light emitted from the light source 92 is guided within the second light guide 98 by total internal reflection from side 1 to side 2. In some embodiments, the second light guide 98 may comprise glass or transparent plastic or some other optically transmissive material. In embodiments, for example wherein the second light guide 98 is comprised of glass, the thickness of the second light guide 98 may be from 200 μm to 1 mm. In certain other embodiments, for example wherein the second light guide is comprised of plastic or other flexible material, the thickness of the second light guide may be from 100 μm to 1 mm. Other materials and thicknesses may be used. In certain embodiments, the length of the second light guide 98 is sufficiently long as to allow the light from the light source 92 to spread uniformly across the width of the second light guide 98 (e.g., on side 2 shown in the embodiment depicted in FIG. 9), for example parallel to the x-axis. In some embodiments the second light guide 98 may comprise the transparent backplate of the display device 90. The backplate of the device may be the packaging enclosing and/or supporting the display elements 96. In some embodiments the backplate may form the hermetically sealed package. In certain other embodiments, wherein the backplate of the display device 90 is not transparent, a second light guide 98 may be disposed forward of the backplate. In such embodiments, the second light guide 98 may incorporate refractive features to diverge the light from the light source 92. In some embodiments comprising a main display element and a sub-display element, wherein the main display element is illuminated with a backlight, the second light guide 98 may comprise the backlight. In embodiments, for example wherein the light guide is comprised of a backplate, the thickness of the light guide may be from 400 to 700 μm or may be up to 1 mm or greater. In certain embodiments, for example wherein the light guide is comprised of a separate component rearward of the display, the thickness of the light guide may be 100 to 700 μm. Values outside these ranges are also possible.
Advantageously, the light source 92 and the second light guide 98 are disposed beneath the plurality of display elements 96. Such a configuration may be useful in reducing the footprint occupied by the display devices as compared to devices with a light source and light being disposed in the side of the front light guide panel such as in FIG. 8.
In some embodiments spacers 99 may be used to separate the display element 96 from the second light guide 98. In some embodiments, the spacers 99 may structurally support the second light guide 98 to the rigid substrate 95. In certain other embodiments, the spacers 99 could be other peripheral adhesive features that attach the backplate to the substrate 95.
A turning mirror 91 is disposed to receive light from the edge of the second light guide 98 which is distal to the light source 91 (side 2) and to direct the light into the edge of the first light guide 97 that is proximal to the turning mirror, in those embodiments wherein the turning film 94 is attached to the substrate 95 with an adhesive layer that has substantially lower refractive index than the turning film 94. Alternatively, when the turning film 94 is attached to the substrate 95 with an index matched adhesive layer, the turning mirror 91 is configured to direct light from the edge of the second light guide 98 into the edge of the substrate 95 that is proximal to the turning mirror. In the embodiment shown in FIG. 9, the turning mirror 91 redirects light propagating generally in the negative y direction and cause it to rotate by 180 degrees and propagate generally in the positive y direction by reflecting a substantial portion of the light. In some embodiments greater than 90% of the light may be reflected by the turning mirror 91.
The turning mirror 91 comprises a reflective surface in the shape of a cylinder. In the embodiment shown in FIG. 9, the reflective surface has a curved cross-section in the Z-Y plane (i.e., parallel to the length of the cylinder that is parallel to the X axis). The curved cross-section may be circular, elliptical, other conics or aspheric. The curved cross-section may be smooth or faceted. The facets can be planar or non-planar. The curved surface may be multifaceted comprising, for example, three, four, five, ten or more facets. In the embodiment shown in FIG. 9, the cross section of the surface of the turning mirror 91 is elliptical. The turning mirror 91 also has an optical aperture that overlaps both the edge of the first light guide 97 and the edge of the second light guide 98 in its optical path. In the embodiment shown, the aperture is larger than the thicker of the first and second light guide. In particular, the aperture is as large as first and second light guides and spacers. The height of the turning mirror (e.g., height of aperture) may be between 0.5 and 2.0 mm. In other embodiments, the height of the turning mirror may be between 0.25 and 1.0 mm. In some embodiments, the turning mirror may have width from 0.25 to 1 or to 3 or 4 millimeters. The turning mirror can have other sizes.
In this particular embodiment, the elliptical cross section of the turning mirror 91 has two line foci, represented by points 9A and 9B in the cross sectional view to FIG. 9. The foci are disposed in the middle of the first light guide 97 and second light guide 98 respectively. If the rays of light that emerge from the edges of the second light guide 98 pass through the first focus 9A, the rays of light will after reflection from the mirror 91 pass through the second focus 9B and be injected into the first light guide 97 with good efficiency, e.g. greater than 50%. The light distribution at the edge of the second light guide 98 towards side 2 will be imaged at the edge of the first light guide 97 towards side 2. Other configurations are possible. For example, the foci 9A, 9B need not be disposed precisely at the center or edge of the first and second light guide. Additionally, in certain embodiments, the mirror has different shape such that first and second line foci are not provided.
Regardless of the shape of the turning mirror 91, light is coupled from the second light guide 98 to the first light guide 97 by the turning mirror. For example, light from light source 92 can be coupled into the second light guide 98 at the side 1. The light propagates within the second light guide 98 from the input edge side 1 to output edge side 2 by total internal reflection. The light rays that are incident on the turning mirror 91 are reflected by the turning mirror 91 into the first light guide 97. The turning film 94 turns light guided in the light guide 97 such that the light is redirected towards the display elements 96. The redirected light passes through the guiding portion 97 substantially normal to the light guide and the array of display elements 96 and is transmitted to the interferometric modulators 96 preferably at normal incidence or close thereto.
In another embodiment the reflective surface of the turning mirror may have a parabolic cross-section. In case of the parabolic turning mirror, the light passing through a line focus of the parabolic reflecting surface will emerge in a direction perpendicular to a directrix of the parabola after reflection. In those embodiments having a parabolic turning mirror, the size and shape of the parabolic reflecting surface can be adjusted to increase or maximize the efficiency of coupling light from the second light guide 98 to the first light guide 97.
In some embodiments, the turning mirror can be solid as compared to a hollow shell. The turning mirror, for example, may comprise a rod of substantially optically transmissive material such as glass or plastic. FIG. 10 illustrates an embodiment of a solid cylindrical turning mirror 100 with a first curved surface 101 and a second planar surface 102. The curved surface 101 has an elliptical cross section along the Z-Y plane (i.e., perpendicular to the length of the cylinder). The planar surface 102 of the turning mirror is flat and can be contacted to the edge of the display device. The curved surface 101 is coated with a reflective layer. In some embodiments, the reflective layer may be metallic. Other reflective coatings including dielectric coating, interference coating, etc. may be used. Light enters the solid turning mirror through the second planar surface 102 and is reflected at the first curved surface 101.
In some embodiments, the turning mirror may be hollowed out and comprise, for example, a shell having two curved surfaces. One of the curved surfaces may be reflective. In one embodiment, for example, where the turning mirror comprises optically transmissive material such as plastic, one of the curved surfaces may be metalized or have a dielectric or interference coating formed thereon. In other embodiments, the turning mirror may comprise metal with one of the curved surfaces being polished to increase reflectivity.
In certain embodiments, the turning mirror may comprise multiple planar reflecting surfaces disposed at an angle with respect to each other. The particular embodiment illustrated in FIG. 11, for example, shows two reflecting planar surfaces angled with respect to each other. The angle between the two planar surfaces can vary between, for example, 90 and 120 degrees or between 90 and 100 degrees or between 90 and 110 degrees. In certain embodiments, the planar mirror surfaces are oriented at an angle of 90, 95100, 105, 110, 115 or 120 degrees with respect to each other. Examples include 97 and 117 degrees. The angles are not limited to those of these particular examples or ranges. The turning mirror described in FIG. 11 comprises a solid rod or be it may be hollowed out as described above. The turning mirror may comprise optically transmissive material such as glass, plastic. In other embodiments, the mirror may be metal. In some other embodiments, the reflecting surface can comprise a metal film or a dielectric film. In some embodiments the reflecting film comprises an interference coating. The two reflecting surfaces can be fused, adhered, or affixed together. In some embodiments, for example, the mirror may be formed by extruding or molding an elongate structure with the planar surfaces thereon. Other methods of forming the two reflecting surfaces may be used.
In operation, light from light source 112 is coupled into the second light guide 118. The light propagates within the second light guide 118 from the input edge side 1 to output edge side 2 by total internal reflection. The light rays from the second light guide 118 are incident on the first reflecting plane 111A of the planar turning mirror 111. After reflection, the light rays are incident on the second reflecting plane 111B. After being reflected by the second reflecting surface 111B, the light rays are incident on the input of the first light guide 117 on side 2. The turning film 114 further comprises a plurality of turning features for turning light guided in the light guide 117 such that the light is redirected towards the display elements 116. The redirected light passes through the guiding portion 117 substantially normal to the light guide 117 and the array of display elements 116 and is transmitted to the interferometric modulators 116 preferably at normal incidence or close thereto.
In certain other embodiments, the turning mirror 121 may have a cross-section in the shape of a trapezoid as illustrated in FIG. 12. One advantage of a trapezoidal geometry for the turning mirror 121 is that the dimension of the turning mirror parallel to the y-axis can be reduced in comparison to the turning mirror 111 of FIG. 11. The trapezoidal turning mirror 121 is formed by three reflecting surfaces 121 a, 121 b and 121 c. Reflecting surfaces 121 a and 121 c are angled with respect to reflecting surface 121 b. The angular separation between reflecting surfaces 121 a and 121 b may be equal to the angle between reflecting surfaces 121 b and 121 c. The angle between the reflecting surfaces 121 a and 121 b may vary between 90 degrees and 151 degrees. The angle between the reflecting surfaces 121 b and 121 c may vary between 90 degrees and 151 degrees. In various embodiments, the angular separation between the reflecting surfaces 121 a and 121 b may be greater than 151 degrees. Similarly in various other embodiments the angular separation between the reflecting surfaces 121 b and 121 c may be greater than 151 degrees.
In certain embodiments, the interferometric modulators may be absorptive to light rays traveling at an angle of 45-90 degrees measured from the normal to the interferometric modulators that are guided within the first light guide. Thus, some of the light propagating through first light guide may be substantially absorbed by the interferometric modulators after a sufficient number of reflections. An optical isolation layer may reduce, minimize, or prevent this loss of light due to absorption. A display device 130 comprising an optical isolation layer 1301 is illustrated in FIG. 13. The turning film 134 of display device 130 is separated from the substrate 135 on which a plurality of interferometric modulators 136 are formed by an optical isolation layer 1301. The display device 130 comprises from front to rear the second light guide 134, optical isolation layer 1301, the substrate 135 and the interferometric modulators 136. Intervening layers may also be included. In these embodiments, the front light guide 137 comprises the turning film 134. The optical isolation layer 1301 advantageously has an index of refraction substantially lower than the glass substrate 135, such that light traveling through the first light guide 137 and striking the glass/optical isolation film interface at an oblique or grazing angle, for example, greater than the critical angle (e.g., greater than 40� or 50� as measured with respect to the normal), will be totally internally reflected back into the first light guide 137 of the illumination apparatus 130. However, light propagating through the first light guide 137 at steep angles (closer to the normal to the array of display elements 136), such as light turned substantially normal to the first light guide 137 by the turning film 134 will be transmitted through the glass/optical isolation film interface. This normally incident light or near normally incident light preferably loses less than about 0.5% of its intensity, and more preferably loses less than about 0.1% of its intensity. Thus the optical isolation layer 1201 forms a boundary for the first light guide 137 such that the light propagating through the first light guide 137 at oblique or grazing angles prior to being turned by the turning film 134 may reflect back into, and continue to propagate through the first light guide 137 until it is turned toward the interferometric modulators 136 by the turning features at near normal incidence, thereby providing an increasingly illuminated display device.
In certain other embodiments, wherein the turning film 144 is separated from the substrate 145 by an optical isolation layer 1401, the substrate 145 on which a plurality of interferometric modulators 146 are formed may be used as the second light guide as illustrated in FIG. 14. The display device 140 comprises from front to rear the turning film 144, optical isolation layer 1401, the substrate 145, the interferometric modulators 146 and the backplate 148. Intervening layers may also be included. A light source 142 is disposed to one side of the substrate 145, for example, side 1. The substrate 145 functions as the second light guide and guides light from the source 142 on side 1 to the turning mirror 141 on side 2. This configuration may be particularly advantageous in reducing the overall thickness of the display device 140.
In various embodiments, the second light guide may be replaced with a light bar. The turning mirror may be used to couple light from the light bar to an edge of the front light guide panel. FIG. 15 illustrates a perspective view of a particular embodiment of a display device 150 comprising of a LED 152, a light bar 154, a turning mirror 151, a light guide panel 155 and a turning film 153. The display device 150 comprises of a reflective display comprising a plurality of reflective elements 156 such as reflective spatial light modulators. A light guide panel 155 is forward of the plurality of reflective elements 156. The light guide panel 155 includes a turning film 153 comprising, for example, a prismatic film. Other methods of forming the turning film 153 and attaching it to the light guide panel 155 such as are described herein may be used as well. As discussed above, the turning film directs light propagating through the light guide panel 155 onto the display elements 156. Light reflected from the display elements 156 then transmitted out of the light guide panel 155 towards the viewer. This design is particularly advantageous in reducing the dimension in the X-Y plane.
In the device shown in FIG. 15, a light source 152 is disposed forward of the light guide panel 155 and the array of display elements 156. The light source 152 is configured so that the direction of emission is parallel to the negative x axis. The light source 152 may comprise an LED. The light bar 154 is disposed with respect to the light source 152 to receive light into the end proximal to the light source 152. The light bar 154 comprises substantially optically transmissive material that supports propagation of light along the length of the light bar 154. Light emitted from the light emitter 152 propagates into the light bar 154 parallel to negative x-axis and is guided therein, for example, via total internal reflection at sidewalls thereof which form interfaces with air or some other surrounding medium. Accordingly, light travels from the end proximal to the light source 152 to a second end distal to the light source 152 of the light bar 154. Reflective sections 158 may be disposed with respect to the side and end of the light bar 154 as shown. Reflectors may also be included above and/or below the light bar 154. The light bar 154 is disposed on a first side (side 1) of the light guide panel 155 and array of display elements 156.
The light bar 154 includes a turning microstructure on one sidewall closer to side 2 in FIG. 15. The light bar 154 is disposed on a first side (side 1) of the light guide panel 155 and array of display elements 156. The turning microstructure is configured to turn at least a substantial portion of the light incident on that side wall of the light bar 154 and to direct a portion of light out of the light bar 154 toward side 1 (in the negative y-direction).
The turning microstructure of the light bar 154 comprises a plurality of turning features. The turning features may comprise triangular facets as shown in FIG. 15. The features shown in FIG. 15 are schematic, not to scale and exaggerated in size and spacing there between. In some embodiments, some or all of the faceted features of the turning microstructure could be formed in a film that is formed on, or laminated to, the light bar 154. In other embodiments, the light bar 154 is formed by molding and the facets are formed in this molding process. The facets or sloping surfaces of the turning features are configured to scatter light out of the light bar 154 along the negative y-axis. Light may, for example, reflect by total internal reflection from a portion of the sidewall of the light bar parallel to the length of the light bar to one of the sloping surfaces. This light may reflect from the sloping surface in a direction out of the light bar 154 toward side 1 of the display in the negative y-direction.
A turning mirror 151 is disposed to receive light propagating in the negative y-direction out of the light bar 154 and turn toward side 1 in the opposite direct (e.g., about by 180 degrees) to propagate along the positive y-direction into the light guide panel 155 toward side 2 of the display. The turning mirror 151 redirects the light by reflection. FIG. 15 illustrates a particular embodiment of a turning mirror 151, formed by two planar reflecting surfaces 151A and 151B disposed at an angle with each other. Alternate embodiments of the turning mirror such as described above may also be used. As described herein, configurations are provided that can produce reduced footprint. Various embodiments employ a turning mirror to accomplish the reduced size. Not all the embodiments need to use a turning mirror or need to produce reduce footprint.
A wide variety of other variations are also possible. Films, layers, components, and/or elements may be added, removed, or rearranged. Additionally, processing steps may be added, removed, or reordered. Also, although the terms film and layer have been used herein, such terms as used herein include film stacks and multilayers. Such film stacks and multilayers may be adhered to other structures using adhesive or may be formed on other structures using deposition or in other manners.
The examples described above are merely exemplary and those skilled in the art may now make numerous uses of, and departures from, the above-described examples without departing from the inventive concepts disclosed herein. Various modifications to these examples may be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other examples, without departing from the spirit or scope of the novel aspects described herein. Thus, the scope of the disclosure is not intended to be limited to the examples shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. The word �exemplary� is used exclusively herein to mean �serving as an example, instance, or illustration.� Any example described herein as �exemplary� is not necessarily to be construed as preferred or advantageous over other examples.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS3439973Jun 25, 1964Apr 22, 1969Siemens AgPolarizing reflector for electromagnetic wave radiation in the micron wavelengthUS3886310Aug 22, 1973May 27, 1975Westinghouse Electric CorpElectrostatically deflectable light valve with improved diffraction propertiesUS3924929Mar 6, 1972Dec 9, 1975Minnesota Mining & MfgRetro-reflective sheet materialUS4228437Jun 26, 1979Oct 14, 1980The United States Of America As Represented By The Secretary Of The NavyWideband polarization-transforming electromagnetic mirrorUS4378567Jan 29, 1981Mar 29, 1983Eastman Kodak CompanyElectronic imaging apparatus having means for reducing inter-pixel transmission nonuniformityUS4421381Mar 11, 1981Dec 20, 1983Yokogawa Hokushin Electric Corp.Mechanical vibrating elementUS4441791Jun 7, 1982Apr 10, 1984Texas Instruments IncorporatedDeformable mirror light modulatorUS4918577Sep 15, 1988Apr 17, 1990Alps Electric Co., Ltd.Illumination light transmitting deviceUS5110370Sep 20, 1990May 5, 1992United Solar Systems CorporationPhotovoltaic device with decreased gridline shading and method for its manufactureUS5142414Apr 22, 1991Aug 25, 1992Koehler Dale RElectrically actuatable temporal tristimulus-color deviceUS5226099Apr 26, 1991Jul 6, 1993Texas Instruments IncorporatedDigital micromirror shutter deviceUS5261970Apr 8, 1992Nov 16, 1993Sverdrup Technology, Inc.Optoelectronic and photovoltaic devices with low-reflectance surfacesUS5291314Jul 29, 1991Mar 1, 1994France TelecomSpatial light modulator device and a conoscopic holography system of large dynamic range including such a modulator deviceUS5339179Oct 1, 1992Aug 16, 1994International Business Machines Corp.Edge-lit transflective non-emissive display with angled interface means on both sides of light conducting panelUS5452385Mar 7, 1994Sep 19, 1995Sharp Kabushiki KaishaOptical scanning device an optical scanning type display and an image data input/output deviceUS5481385Jul 1, 1993Jan 2, 1996Alliedsignal Inc.Direct view display device with array of tapered waveguide on viewer sideUS5550373Dec 30, 1994Aug 27, 1996Honeywell Inc.Fabry-Perot micro filter-detectorUS5579149Sep 12, 1994Nov 26, 1996Csem Centre Suisse D'electronique Et De Microtechnique SaMiniature network of light obturatorsUS5615024Aug 10, 1993Mar 25, 1997Sharp Kabushiki KaishaColor display device with chirped diffraction gratingsUS5647036Sep 9, 1994Jul 8, 1997Deacon ResearchProjection display with electrically-controlled waveguide routingUS5671994Jun 8, 1994Sep 30, 1997Clio Technologies, Inc.Flat and transparent front-lighting system using microprismsUS5673128Dec 28, 1995Sep 30, 1997Sharp Kabushiki KaishaBack light device of liquid crystal deviceUS5712694Sep 14, 1995Jan 27, 1998Kabushiki Kaisha ToshibaDisplay deviceUS5771321Jan 4, 1996Jun 23, 1998Massachusetts Institute Of TechnologyMicromechanical optical switch and flat panel displayUS5808708 *Dec 14, 1995Sep 15, 1998Sharp Kabushiki KaishaLighting apparatusUS5883684Jun 19, 1997Mar 16, 1999Three-Five Systems, Inc.Diffusively reflecting shield optically, coupled to backlit lightguide, containing LED's completely surrounded by the shieldUS5892598Apr 3, 1995Apr 6, 1999Matsushita Electric Industrial Co., Ltd.Head up display unit, liquid crystal display panel, and method of fabricating the liquid crystal display panelUS5913594Feb 25, 1997Jun 22, 1999Iimura; KeijiFlat panel light source device and passive display device utilizing the light source deviceUS5920417Jul 19, 1994Jul 6, 1999Medcam, Inc.Microelectromechanical television scanning device and method for making the sameUS5956106Feb 1, 1996Sep 21, 1999Physical Optics CorporationIlluminated display with light source destructuring and shaping deviceUS6008449Aug 19, 1997Dec 28, 1999Cole; Eric D.Reflective concentrating solar cell assemblyUS6040937Jul 31, 1996Mar 21, 2000Etalon, Inc.Interferometric modulationUS6055090Jan 27, 1999Apr 25, 2000Etalon, Inc.Interferometric modulationUS6074069Jan 20, 1999Jun 13, 2000Industrial Technology Research InstituteBacklight source device with circular arc diffusion unitsUS6099134Sep 26, 1997Aug 8, 2000Hitachi, Ltd.Liquid crystal display deviceUS6123431Mar 18, 1998Sep 26, 2000Sanyo Electric Co., LtdBacklight apparatus and light guide plateUS6151089 *Jan 20, 1999Nov 21, 2000Sony CorporationReflection type display with light waveguide with inclined and planar surface sectionsUS6195196Oct 29, 1999Feb 27, 2001Fuji Photo Film Co., Ltd.Array-type exposing device and flat type display incorporating light modulator and driving method thereofUS6199989Oct 25, 1999Mar 13, 2001Sumitomo Chemical Company, LimitedOptical plate having reflecting function and transmitting functionUS6259082Jul 30, 1998Jul 10, 2001Rohm Co., Ltd.Image reading apparatusUS6273577Oct 30, 1998Aug 14, 2001Sanyo Electric Co., Ltd.Light guide plate, surface light source using the light guide plate, and liquid crystal display using the surface light sourceUS6292504Mar 16, 1999Sep 18, 2001Raytheon CompanyDual cavity laser resonatorUS6322901Nov 13, 1997Nov 27, 2001Massachusetts Institute Of TechnologyHighly luminescent color-selective nano-crystalline materialsUS6323415Sep 17, 1999Nov 27, 2001Hitachi, Ltd.Light concentrator photovoltaic module method of manufacturing same and light concentrator photovoltaic systemUS6359668May 13, 1998Mar 19, 2002Seiko Epson CorporationDisplay device and electronic apparatus using the sameUS6371623Jul 21, 2000Apr 16, 2002Minebea Co., Ltd.Spread illuminating apparatus with a means for controlling light directivityUS6377233Jul 30, 2001Apr 23, 2002International Business Machines CorporationMicromechanical display and fabrication methodUS6407785Sep 29, 1999Jun 18, 2002Semiconductor Energy Laboratory Co., Ltd.Reflection type semiconductor display device having optical fiber adjacent the surface of the main bodyUS6412969Dec 14, 1999Jul 2, 2002Sharp Kabushiki KaishaBacklighting device and a method of manufacturing the same, and a liquid crystal display apparatusUS6454452Oct 20, 2000Sep 24, 2002Mitsubishi Denki Kabushiki KaishaBacklight for liquid crystal display deviceUS6504589Feb 17, 1998Jan 7, 2003Dai Nippon Printing Co., Ltd.Backlight device and liquid crystal display deviceUS6519073Jan 10, 2000Feb 11, 2003Lucent Technologies Inc.Micromechanical modulator and methods for fabricating the sameUS6522794Jan 31, 2000Feb 18, 2003Gemfire CorporationFlat; routing laser light toward viewer; electrooptics; high resolution computer displays; high definition televisionUS6582095Jun 1, 2000Jun 24, 2003Minebea Co., Ltd.Spread illuminating apparatusUS6592234Apr 6, 2001Jul 15, 20033M Innovative Properties CompanyFrontlit displayUS6597490Nov 27, 2001Jul 22, 2003Coretek, Inc.Electrically tunable fabry-perot structure utilizing a deformable multi-layer mirror and method of making the sameUS6598987Jun 15, 2000Jul 29, 2003Nokia Mobile Phones LimitedMethod and apparatus for distributing light to the user interface of an electronic deviceUS6603520Dec 21, 2001Aug 5, 2003Nitto Denko CorporationOptical film and liquid-crystal display deviceUS6631998Aug 31, 2001Oct 14, 2003Minebea Co., Ltd.Spread illuminating apparatusUS6636358Feb 1, 2001Oct 21, 2003Nitto Denko CorporationOptical filmUS6642913Jan 19, 2000Nov 4, 2003Fuji Photo Film Co., Ltd.Light modulation element, exposure unit, and flat-panel display unitUS6643067Nov 15, 2001Nov 4, 2003Seiko Epson CorporationElectro-optical device and electronic apparatusUS6650455Nov 13, 2001Nov 18, 2003Iridigm Display CorporationPhotonic mems and structuresUS6652109Dec 11, 2001Nov 25, 2003Alps Electric Co., Ltd.Surface light emission device, method of manufacturing the same, and liquid crystal display deviceUS6669350Dec 13, 2001Dec 30, 2003Mitsubish Rayon Co., Ltd.Planar light source system and light deflecting device thereforUS6674562Apr 8, 1998Jan 6, 2004Iridigm Display CorporationInterferometric modulation of radiationUS6680792Oct 10, 2001Jan 20, 2004Iridigm Display CorporationInterferometric modulation of radiationUS6683693May 19, 2000Jan 27, 2004Kabushiki Kaisha TopconTarget deviceUS6697403Apr 16, 2002Feb 24, 2004Samsung Electronics Co., Ltd.Light-emitting device and light-emitting apparatus using the sameUS6741377Jul 2, 2002May 25, 2004Iridigm Display CorporationReducing contribution of reflected ambient light from inactive areas of microoptical electromechanical apparatusUS6742907May 8, 2003Jun 1, 2004Seiko Epson CorporationIllumination device and display device using itUS6751023Feb 1, 2001Jun 15, 2004Nitto Denko CorporationOptical filmUS6761461Nov 15, 2002Jul 13, 2004Minebea Co., Ltd.Spread illuminating apparatus without light conductive barUS6773126May 19, 2000Aug 10, 2004Oy Modilis Ltd.Light panel with improved diffractionUS6792293Sep 13, 2000Sep 14, 2004Motorola, Inc.Apparatus and method for orienting an image on a display of a wireless communication deviceUS6794119Feb 12, 2002Sep 21, 2004Iridigm Display CorporationMethod for fabricating a structure for a microelectromechanical systems (MEMS) deviceUS6798469Jun 15, 2001Sep 28, 2004Fuji Photo Film Co., Ltd.Optical element, optical light source unit and optical display device equipped with the optical light source unitUS6819380Jun 11, 2003Nov 16, 2004Toppoly Optoelectronics Corp.Double-sided LCD panelUS6829258Jun 26, 2002Dec 7, 2004Silicon Light Machines, Inc.Rapidly tunable external cavity laserUS6853418Sep 4, 2002Feb 8, 2005Mitsubishi Denki Kabushiki KaishaLiquid crystal display deviceUS6862141May 20, 2002Mar 1, 2005General Electric CompanyOptical substrate and method of makingUS6864882Mar 22, 2001Mar 8, 2005Next Holdings LimitedProtected touch panel display systemUS6871982Jan 22, 2004Mar 29, 2005Digital Optics International CorporationHigh-density illumination systemUS6879354Sep 13, 1999Apr 12, 2005Sharp Kabushiki KaishaFront-illuminating device and a reflection-type liquid crystal display using such a deviceUS6880959Aug 25, 2003Apr 19, 2005Timothy K. HoustonVehicle illumination guideUS6882461Mar 29, 2004Apr 19, 2005Prime View International Co., LtdMicro electro mechanical system display cell and method for fabricating thereofUS6883924Mar 6, 2002Apr 26, 2005Fujitsu LimitedLighting apparatus and liquid crystal displayUS6883934Jul 12, 2001Apr 26, 2005Seiko Epson CorporationLight source device, illumination device liquid crystal device and electronic apparatusUS6897855Feb 16, 1999May 24, 2005Sarnoff CorporationTiled electronic display structureUS6930816Jan 16, 2004Aug 16, 2005Fuji Photo Film Co., Ltd.Spatial light modulator, spatial light modulator array, image forming device and flat panel displayUS6951401 *Jun 3, 2002Oct 4, 2005Koninklijke Philips Electronics N.V.Compact illumination system and display deviceUS6964484Feb 2, 2004Nov 15, 2005Hewlett-Packard Development Company, L.P.Overfill reduction for an optical modulatorUS7042444Jan 17, 2003May 9, 2006Eastman Kodak CompanyOLED display and touch screenUS7042643Feb 19, 2002May 9, 2006Idc, LlcInterferometric modulation of radiationUS7050219Jun 17, 2002May 23, 2006Fuji Photo Film Co., Ltd.Light-modulating element, display element, and exposure elementUS7056001Jun 16, 2003Jun 6, 2006Toppoly Optoelectronics Corp.Back light module for flat display deviceUS7072093Apr 30, 2003Jul 4, 2006Hewlett-Packard Development Company, L.P.Optical interference pixel display with charge controlUS7072096Dec 13, 2002Jul 4, 2006Digital Optics International, CorporationUniform illumination systemUS7123216Oct 5, 1999Oct 17, 2006Idc, LlcPhotonic MEMS and structuresUS7133022Nov 6, 2002Nov 7, 2006Keyotee, Inc.Apparatus for image projectionUS7142347Aug 8, 2005Nov 28, 2006Cheetah Omni, LlcMethod and system for processing photonic systems using semiconductor devicesUS7187489Jun 1, 2006Mar 6, 2007Idc, LlcPhotonic MEMS and structuresUS7477809 *Jul 31, 2007Jan 13, 2009Hewlett-Packard Development Company, L.P.Photonic guiding deviceUS7663714 *Aug 9, 2005Feb 16, 2010Sony CorporationBacklight device and color liquid crystal display apparatusUS20020044445 *Dec 1, 2000Apr 18, 2002Bohler Christopher L.Sold state light source augmentation for slm display systemsUS20030043157 *Aug 19, 2002Mar 6, 2003Iridigm Display CorporationPhotonic MEMS and structuresUS20030098957 *Nov 27, 2002May 29, 2003Haldiman Robert C.System, method and apparatus for ambient video projectionUS20070241340 *Apr 17, 2006Oct 18, 2007Pan Shaoher XMicro-mirror based display device having an improved light sourceDE19942513A1 *Sep 7, 1999Mar 8, 2001Gerhard KarlLeuchtk�rper f�r durchleuchtungsf�hige BilderDE102007025092A1 *May 30, 2007Dec 4, 2008Osram Opto Semiconductors GmbhLumineszenzdiodenchipJPS60242408A * Title not available* Cited by examinerNon-Patent CitationsReference1Amendment and Response in U.S. Appl. No. 11/187,784 dated Mar. 30, 2009.2Amendment and Response in U.S. Appl. No. 11/187,784 dated Nov. 19, 2008.3Amendment under 37 CFR 1.312 in U.S. Appl. No. 11/187,784 dated May 7, 2010.4Application as filed in U.S. Appl. No. 12/821,070 dated Jun. 22, 2010.5Extended European Search Report for Application No. EP 08 07 5318 dated Mar. 5, 2009.6Extended European Search Report in App. No. 08153691.4 dated Mar. 25, 2009.7Extended European Search Report in EP10176261 dated Dec. 8, 2010.8Extended European Search Report in European Application No. 08153690.6 dated Mar. 5, 2009.9Extended Search Report in European Application No. 08075318.9 (Published EP 2 040 114), dated Mar. 5, 2009.10Fan et al., "Channel Drop Filters in Photonic Crystals", Optics Express, vol. 3, No. 1, pp. 4-11, 1998.11Giles et al., "Silicon MEMS Optical Switch Attenuator and Its Use in Lightwave Subsystems", IEEE Journal of Selected Topics in Quantum Electronics, vol. 5. No. 1, pp. 18-25, Jan./Feb. 1999.12International Preliminary Report on Patentability in PCT/US2005/030441 dated Apr. 5, 2007.13International Search Report and Written Opinion in PCT/US2005/030441(International Publication No. WO 2006/036415) dated Dec. 12, 2005.14International Search Report and Written Opinion in PCT/US2008/085010 dated Mar. 4, 2009.15Little et al., "Vertically Coupled Microring Rosonator Channel Dropping Filter", IEEE Photonics Technology Letters, vol. 11, No. 2, pp. 215-217, 1999.16Magel, "Integrated Optic Devices Using Micromachined Metal Membranes", SPIE vol. 2686, 0-8194-2060-3, pp. 54-63, 1996.17Mehregany, et. al., "MEMS applications in Optical Systems," IEEE/LEOS 1996 Summer Topical Meetings, pp. 75-76, Aug. 1996.18Miles, M., et. al., "Digital Paper(TM) for reflective displays," Journal of the Society for Information Display, Society for Information Display, San Jose, US, vol. 11, No. 1, pp. 209-215, 2003.19Miles, M., et. al., "Digital Paper� for reflective displays," Journal of the Society for Information Display, Society for Information Display, San Jose, US, vol. 11, No. 1, pp. 209-215, 2003.20Miles, M.W., "Interferometric Modulation MOEMS as an enabling technology for high-performance reflective displays," Proceedings of the SPIE, vol. 4985, pp. 131-139, 28, Jan. 2003.21Neal T.D., et. al., "Surface Plasmon enhanced emission from dye doped polymer layers," Optics Express Opt. Soc. America, USA, vol. 13, No. 14, pp. 5522-5527, Jul. 11, 2005.22Notice of Allowance in U.S. Appl. No. 11/187,784 dated Feb. 8, 2010.23Notice of Allowance in U.S. Appl. No. 11/187,784 dated Jun. 5, 2009.24Notice of Allowance in U.S. Appl. No. 11/187,784 dated Oct. 21, 2009.25Notice of Allowance in U.S. Appl. No. 12/423,354 mailed Sep. 1, 2010.26Office Action in Japanese Application No. 2007-533487 mailed Sep. 7, 2010.27Office Action in U.S. Appl. No. 11/187,784 dated Feb. 17, 2009.28Office Action in U.S. Appl. No. 11/187,784 dated Oct. 7, 2008.29Official Communication in Chinese Application No. 200580030964.X dated Jun. 6, 2008.30Official Communication in European Application No. 05 791 508.4 (Publication No. EP 2040114) dated Jul. 19, 2007.31Official Communication in European Patent Application No. 08 075 318.9 dated Oct. 30, 2009.32Official Communication in Japanese Application No. 2007-533487, dated Sep. 7, 2010.33Official Communication in Russian Application No. 2007115881 dated Aug. 25, 2009.34Oliner, "Radiating Elements and Mutual Coupling," Microwave Scanning Antennas, vol. 2, pp. 131-157 and pp. 190-194, 1966.35OSRAM Opto Semiconductors, "Multi Micro SIDELED," Preliminary Data, Dec. 11, 2008.36Partial European Search Report in EP10176266 dated Dec. 9, 2010.37Preliminary Amendment in U.S. Appl. No. 12/821,070 dated Aug. 24, 2010.38RCE and IDS in U.S. Appl. No. 11/187,784 dated Jan. 20, 2010.39RCE and IDS in U.S. Appl. No. 11/187,784 dated Sep. 3, 2009.40RCE and IDS in U.S. Appl. No. 12/423,354 mailed Sep. 14, 2010.41Substantive Examination Report in Malaysian App. No. PI 20054177 dated Apr. 10, 2009.42Substantive Examination Report in Malaysian Patent Application No. PI20054177 dated Dec. 15, 2009.43Tai C.Y., et. al., "A Transparent Frontlighting System for Reflective-Type Displays," 1995 SID International Symposium Digest of Technical Papers, vol. 26, pp. 375-378, May 23, 1995.44Zhou et al., "Waveguide Panel Display Using Electromechanical Spatial Modulators" SID Digest, vol. XXIX, 1998.Referenced byCiting PatentFiling datePublication dateApplicantTitleUS8411026Sep 2, 2011Apr 2, 2013Qualcomm Mems Technologies, Inc.Methods and devices for lighting displaysUS8596846Mar 16, 2012Dec 3, 2013Nano-Optic Devices, LlcFrontlight unit for enhancing illumination of a reflective displayUS20100231498 *Mar 13, 2009Sep 16, 2010Microsoft CorporationImage display via multiple light guide sectionsUS20130135255 *Nov 30, 2011May 30, 2013Qualcomm Mems Technologies, Inc.Display systems including optical touchscreen* Cited by examinerClassifications U.S. Classification385/31, 362/97.3, 385/129, 362/600, 362/560, 362/617, 362/603, 362/97.2, 362/97.1, 362/602, 362/561, 362/607, 362/330, 385/131International ClassificationG02B6/42, G02B6/26Cooperative ClassificationG02B6/0031, G02B6/0038, G02B6/0028, G02B6/0076, G02B17/023, G02B26/001European ClassificationG02B6/00L6I8G, G02B6/00L6T2Legal EventsDateCodeEventDescriptionNov 1, 2011CCCertificate of correctionJul 29, 2009ASAssignmentOwner name: QUALCOMM MEMS TECHNOLOGIES, INC., CALIFORNIAFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:QUALCOMM INCORPORATED;REEL/FRAME:023022/0021Effective date: 20090601May 4, 2009ASAssignmentOwner name: QUALCOMM INCORPORATED, CALIFORNIAFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:MIENKO, MAREK;XU, GANG;BITA, ION;AND OTHERS;REEL/FRAME:022636/0742;SIGNING DATES FROM 20071207 TO 20080131Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:MIENKO, MAREK;XU, GANG;BITA, ION;AND OTHERS;SIGNING DATES FROM 20071207 TO 20080131;REEL/FRAME:022636/0742RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services©2012 Google