EMBEDDED RELAY LENS FOR HEAD-UP DISPLAYS OR THE LIKE
Briefly, in accordance with one or more embodiments, an optical relay comprises a partially-reflective-coated Fresnel lens or similar low-profile lens such as a diffractive lens or a holographic lens having a first index of refraction and a filler medium having a second index of refraction and being disposed adjacent to the Fresnel lens. The optical relay enables the optical power of the Fresnel or similar low-profile lens embedded within the two layers to influence a beam that is reflected from the optical relay while allowing transmitted light to experience little or no influence from the embedded lens.
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In a head-up display (HUD), optical design is made more complex by a design constraint to keep the optical relay lens or lenses out of the direct line of sight of the driver, pilot or viewer. Typically, meeting this design constraint results in adding a combiner or using the windshield as a combiner where the function of the combiner is to combine the image from the HUD projector with the view of the world directly in front of the driver, pilot, or viewer. The main relay optics for an automotive HUD are typically housed inside the dashboard, with the output light projected upward onto the windshield which reflects a portion of the light back towards the driver where not much space may be available, and where the optical path may be relatively complex.
Claimed subject matter is particularly pointed out and distinctly claimed in the concluding portion of the specification. However, such subject matter may be understood by reference to the following detailed description when read with the accompanying drawings in which:
It will be appreciated that for simplicity and/or clarity of illustration, elements illustrated in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, if considered appropriate, reference numerals have been repeated among the figures to indicate corresponding and/or analogous elements.
DETAILED DESCRIPTIONIn the following detailed description, numerous specific details are set forth to provide a thorough understanding of claimed subject matter. However, it will be understood by those skilled in the art that claimed subject matter may be practiced without these specific details. In other instances, well-known methods, procedures, components and/or circuits have not been described in detail.
In the following description and/or claims, the terms coupled and/or connected, along with their derivatives, may be used. In particular embodiments, connected may be used to indicate that two or more elements are in direct physical and/or electrical contact with each other. Coupled may mean that two or more elements are in direct physical and/or electrical contact. However, coupled may also mean that two or more elements may not be in direct contact with each other, but yet may still cooperate and/or interact with each other. For example, “coupled” may mean that two or more elements do not contact each other but are indirectly joined together via another element or intermediate elements. Finally, the terms “on,” “overlying,” and “over” may be used in the following description and claims. “On,” “overlying,” and “over” may be used to indicate that two or more elements are in direct physical contact with each other. However, “over” may also mean that two or more elements are not in direct contact with each other. For example, “over” may mean that one element is above another element but not contact each other and may have another element or elements in between the two elements. Furthermore, the term “and/or” may mean “and”, it may mean “or”, it may mean “exclusive-or”, it may mean “one”, it may mean “some, but not all”, it may mean “neither”, and/or it may mean “both”, although the scope of claimed subject matter is not limited in this respect. In the following description and/or claims, the terms “comprise” and “include,” along with their derivatives, may be used and are intended as synonyms for each other.
Referring now to
In one or more embodiments, optical relay 100 may be utilized in a scanned-beam projector, for example a laser based scanned-beam projector. In one or more alternative embodiments, optical relay may be utilized in a non scanned-beam type projector for example a digital light projector (DLP), liquid-crystal display (LCD) type projector, and so on, and the scope of the claimed subject matter is not limited in this respect. For achieving reduced diffractive artifacts in the case of using optical relay 100 in conjunction with a laser or non-laser-based one-dimensional-scanned or two-dimensional panel display, the minimum Fresnel pitch can be estimated to be on the order of the footprint, as projected on or traced to the Fresnel relay, of the minimum cone numerical aperture (NA) representing the resolvable pixel resolution of the display panel being projected.
In one or more embodiments, the overall shape of optical relay 100 may be relatively flat or planar, or alternatively may be non-planar and have at least a slight curve on one or more surfaces thereof, where such a curvature may be spherical or aspherical, with Fresnel lens 112 having a spherical or aspherical curvature, although the scope of the claimed subject matter is not limited in these respects. In some embodiments, optical relay 100 may be a relatively thinner and optically transparent device, or alternative optical relay 110 may comprise an off-axis section of a Fresnel or diffractive lens 112 which may be a slightly thicker but still moderately thin and see-through device. Optical relay 100 and/or optical relay 110 may be a stand-alone device that is added for example in front of or behind a windshield or windscreen of a vehicle or of a helmet or other head-worn device, or alternatively optical relay 100 and/or optical relay 110 may be disposed within or otherwise formed as part of or integral with such a windshield or windscreen, and the scope of the claimed subject matter is not limited in these respects.
In one or more embodiments, optical relay 100 comprises a reflective Fresnel lens 112 having a surface 122 disposed between two refractive index media having a first index of refraction n1 and a second index of refraction n2, such that the ratio between n1 and n2 may be selected to implement a reflective and/or powered optical element. In one or more embodiments, n1 may be equal to, or nearly equal to, n2 although the scope of the claimed subject matter is not limited in this respect. For example, for an optical relay 100 having parallel outer surfaces of layer 114 and layer 116, having equal or nearly equal indices n1 and n2 allows optical relay 100 to be see-through with no magnification of a see-through image, and Fresnel or diffractive lens or reflector 112 may still have its own magnification power. In contrast, providing at least sufficiently different two indices n1 and n2 disposed on opposed sides of the Fresnel or diffractive lens or reflector 112 can serve to affect magnification of a see-through image while still maintaining the power of the reflective or diffractive Fresnel lens 112 Fresnel component. Such an arrangement may be contrasted with the embodiment wherein a combination of adding curvature, and thus power, to the outer surfaces of layers 114 and 116 of the element sandwich of which optical relay 100 is comprised, thereby giving a lensing affect to a see-through image, and in some cases to both a see-through as well as reflected virtual image. Such an arrangement may provide one or more additional degrees of freedom in the design and usage of optical relay 100, for example using curvature of the outer surfaces of layers 114 and 116, both on-axis and off-axis spherical, aspheric, or planar, as well as curvature of the embedded Fresnel lens 112, and/or both on and off-axis spherical and aspheric Fresnel reflector surface 112. Furthermore, in one or more embodiments it is also possible to actually have the inner surfaces of layers 114 and 116 to be curved in addition to the curvature of the outer surfaces of layers 114 and 116 so as to still allow fairly-low see-through distortion while adding a even more design degrees-of-freedom in the correction capability of the projected image. Such additional correction obtained may be greater correction than allowed by just the Fresnel lens or reflector 112 alone on the reflective system side of the element.
In one or more embodiments, Fresnel lens or reflector 112 may be manufactured to be relatively thin and imaged in a tilted on-axis or normal-to-viewer off-axis case, for example as shown in
In one or more embodiments, optical relay 100 may be capable of enabling a virtual display such that if a user looks through optical relay 100 while an image is projected onto optical relay 100, for example as shown in and described with respect to
In one or more embodiments, optical relay 100 having Fresnel lens 112 may be generally constructed as follows. Fresnel lens 112 may comprise a surface 122 embedded between adjacent media of refractive index n1 and n2. Outer layers of adjacent media comprising first layer 114 and second layer 116 may be either planar or non-planar. In one or more embodiments, surface 122 of Fresnel lens 112 may have a reflective coating, or an at least partially reflective coating, disposed thereon. An effective focal length of Fresnel lens 112 may be at least defined by a Fresnel surface profile of the Fresnel elements of which Fresnel lens is composed and the refractive index of the media adjacent to the Fresnel surface. In one or more embodiments, such a Fresnel surface profile of Fresnel lens 112 may be spherical, aspherical, anamorphic, on-axis or off-axis, and so on. If the refractive indices of Fresnel lens 112 and filler 120 are set such that n1 is approximately equal n2, Fresnel lens 112 is essentially see through, or nearly see through, with no power for the portion of light that originates from the opposite side of optical relay with respect to the side which the viewer is viewing, while the light from a projector may be imaged and relayed toward the viewer's eye. Furthermore, in one or more embodiments, if the indices are not set to be sufficiently equal or nearly equal, in such an arrangement optical relay 100 may achieve magnification of the background image while simultaneously viewing virtual overlay content projected from the projector.
In one or more embodiments, polarization coatings and/or retarders may be applied to various surfaces of optical relay 100, for example on surface 122 of Fresnel lens 112, and/or one or more surfaces of first layer 114 and/or second layer 116, and/or on a surface of a windshield or windscreen with which optical relay 100 is utilized, to enable various polarization input versus output relationships, so as to allow, for example, compatibility of optical relay 100 with the viewer's sunglasses, and so on. In addition, optical relay 100 may include various other coatings, layers, and/or surfaces, for example selective, reflective, absorptive, and/or polarization coatings or surfacing, which optionally may be applied to the step-wall features of Fresnel lens 112, for example to reduce scatter effects by absorption, reflection, and/or controlled direction and/or controlled scatter. However, such coatings, layers, and/or surfacing are example elements that may be included with or in conjunction with optical relay 100 to achieve desired effects or results, and the scope of the claimed subject matter is not limited in these respects. In one or more embodiments, diffraction effects exhibited by optical relay 100 may be reduced or minimized. For example, in an embodiment of optical relay having an embedded and see through Fresnel lens 112, the spacing of the Fresnel elements of Fresnel lens 112 may be chosen on the order of the diffractive beamlet spacing, or diffraction-limited cone NA, of a pixel within an image plane internal to the projector with which optical relay 100 is utilized in order to diminish the effects of diffraction emanating from optical projector 210, although the scope of the claimed subject matter is not limited in this respect. An example scanned beam head-up display projector capable of utilizing optical relay 100 is shown in and described with respect to
Referring now to
In the embodiment shown in
Referring now to
Referring now to
In one or more embodiments, the Z-biasing 416 placement of projector 210 may be adjusted, in combination with the placement of the Fresnel elements of Fresnel lens 112 along with the tilt or lens offset of the Fresnel elements along optical path to reduce or eliminate shadowing and scattering effects due to diffraction and/or to maintain contrast in the projected image. In some instances an aberration-free field of view (FOV) may be desired, therefore in some embodiments such as shown in
In the embodiment shown in
In one or more embodiments, head-up display system 200, and/or near-to-eye head-worn display system 400, may be designed for a range of acceptance for optical relay 100, and is not limited to the fixed angle α of the projector 210. In such projectors, the apparent virtual image can be placed where desired for the particular application of the projectors, and is not limited to an existing physical plane. In one or more embodiments, wavelength-selective filtering may be utilized at the surface 122 of Fresnel lens 112, and/or absorbing dye may be utilized just beyond the surface 122 of Fresnel lens 112 for non-see-through applications that may utilize a relatively thinner relay for reduced glare, for example as utilized in a multiple display region system as discussed with respect to
Referring now to
In one or more embodiments, the multiple display regions of projector display system 500, for example first display region 512 and second display system 514 may comprise different materials optimized to type of content to be displayed in the respective display regions. Projection of the images in the multiple regions may be generated by a single projector or alternatively from multiple projectors. In one or more embodiments, the display region may be divided into at least two or more regions, such as first display region 512 and second display region 514, where two or more of the regions comprise different surfaces, geometries, lenses, magnification, optical relays, and so on, optimized for the type of image content to be displayed in a given regions. Such an arrangement of the multiple display regions for projector display system 500 may allow various display scenarios tailored to the given automobile or other vehicle in which projector display system 500 is deployed. For example, projector display system 500 may be capable of displaying automotive safety information on a more transparent portion of the windshield 510 or other display structure in a Head-Up Display (HUD) mode, for example in first display region 512, wherein the HUD display information is intended to be viewed by the driver while driving the vehicle. Likewise images or video may be displayed on a different section of the same windshield 510 another display area, for example in second display region 514, wherein the images or video are intended to be viewed by a passenger in the vehicle. Such an arrangement of projector display system 500 allows multiple benefits from integrating multiple systems all utilized and viewable from a single location such as a windshield 510 of an automobile or other vehicle. Furthermore, one or more of the multiple display regions of projector display system 500 include speckle reduction technology in the display region of the windshield where such technology would result in a higher quality display solution, for example for HUD type information displayed in first display region 512. In one or more embodiments, the shape of a given display region may be selected based at least in part on the particular application in which projector display system 500 is deployed. Furthermore, any combination of shape, design, and/or other technology addressing needs of the user and/or the particular application could be utilized in combination for such a projector display system 500. It should be noted that these are particular examples of how multiple display regions in projector display system 500 could be implemented, and the scope of the claimed subject matter is not limited in these respects.
Referring now to
In one or more embodiments, optical relay 100 may be see-through or may add magnification to see-through via a prescription with overlay. Such a magnification may be achieved via combinations of differences in the respective indices of refraction n1 of layer 116, n2 of filler 120, n3 of filler 120, and/or n4 of layer 114, in selected combinations thereof. Likewise, magnification may be achieved via combinations of curvatures of surface s1 and/or surface s2 of layer 116, surface s3 of Fresnel lens 112, and/or surface s4 and/or surface s5 of layer 114. Furthermore, magnification may be achieved or controlled via any combination of selected refractive indices n1, n2, n3, and/or n4 along with surface curvatures surface s1, s2, s3, s4 and/or s5, although the scope of the claimed subject matter is not limited in these respects.
Although the claimed subject matter has been described with a certain degree of particularity, it should be recognized that elements thereof may be altered by persons skilled in the art without departing from the spirit and/or scope of claimed subject matter. It is believed that the subject matter pertaining to an embedded relay lens for head-up displays or the like and/or many of its attendant utilities will be understood by the forgoing description, and it will be apparent that various changes may be made in the form, construction and/or arrangement of the components thereof without departing from the scope and/or spirit of the claimed subject matter or without sacrificing all of its material advantages, the form herein before described being merely an explanatory embodiment thereof, and/or further without providing substantial change thereto. It is the intention of the claims to encompass and/or include such changes.
Claims
1. An optical relay, comprising:
- a lens having an at least partially reflective coating and having a first index of refraction, the lens comprising a Fresnel lens, a diffractive lens, a holographic lens, or combinations thereof, wherein the at least partially reflective coating is a neutral density filter;
- a filler medium having a second index of refraction and being disposed adjacent to the lens, wherein at least one of the lens or the filler medium, or combinations thereof, is at least partially transparent;
- a polarizing beam splitter disposed between the integrated photonics module and the optical relay; and
- a retarder or a beam splitter, or combinations thereof, disposed proximate to the lens.
2. An optical relay as claimed in claim 1, wherein the lens has a generally planar profile, a slightly curved profile, an elliptical curved profile, a spherical curved profiled, or an aspheric curved profile, or combinations thereof.
3. An optical relay as claimed in claim 1, wherein the first index of refraction is equal to or approximately equal to the second index of refraction.
4. An optical relay as claimed in claim 1, wherein the first index of refraction is sufficiently different from the second index of refraction to provide magnification of an image transmitted through the lens.
5. An optical relay as claimed in claim 1, further comprising:
- a first layer and a second layer, wherein the first layer and the second layer are at least partially transparent;
- wherein the lens and the filler medium are disposed between the first layer and the second layer.
6. An optical relay as claimed in claim 1, further comprising:
- a first layer and a second layer, wherein the first layer and the second layer are at least partially transparent;
- wherein the lens and the filler medium are disposed between the first layer and the second layer, and the first layer or the second layer, or combinations thereof, have a curvature to provide magnification to an image transmitted through the lens, wherein the curvature comprises an inner surface of the first layer, an outer surface of the first layer, an inner surface of the second layer, or an outer surface of the second layer, or combinations thereof.
7. A head-up display system for a vehicle, comprising:
- a projector to display a projected image; and
- an optical relay onto which the image is projected from a first side of the optical relay to allow a viewer to view the projected image through the optical relay wherein the virtual projected image is displayed on another side of the optical relay;
- wherein the optical relay comprises:
- a lens having an partially-reflective coating and a first index of refraction, wherein the lens comprises a Fresnel lens, a diffractive lens, or a holographic lens, or combinations thereof, wherein the partially reflective coating is a neutral density filter;
- a filler medium having a second index of refraction and being disposed adjacent to the lens, wherein at least one of the lens or the filler medium, or combinations thereof, is at least partially transparent;
- a polarizing beam splitter disposed between the integrated photonics module and the optical relay; and
- a retarder or a beam splitter, or combinations thereof, disposed proximate to the lens.
8. A head-up display system as claimed in claim 7, wherein the projected beam from the projector is arranged to impinge generally on-axis with respect to the optical relay, wherein the projected beam generally normal to a plane of the optical relay bisects or nearly bisects an angle between the projector and a viewer, and the optical relay is generally tilted with respect to a line of sight of the viewer.
9. A head-up display system as claimed in claim 7, wherein the projected beam from the projector is arranged to impinge generally off-axis with respect to the optical relay, wherein the projected beam normal to the plane of the optical relay does not bisect or nearly bisect an angle between the projector and a viewer, and the optical relay is disposed generally normal with respect to a line of sight of the viewer.
10. A head-up display system as claimed in claim 7, further comprising a windshield, wherein the optical relay is disposed adjacent to the windshield or integrated within the windshield, or combinations thereof.
11. A head-up display system as claimed in claim 7, further comprising a windshield, wherein the windshield has a first display region in which a first type of image may be displayed, and the windshield has a second display region in which a second type of image may be displayed, wherein the optical relay is at least partially disposed within the first display region for displaying the projected image projected by the integrated photonics module.
12. A head-up display system as claimed in claim 7, wherein the lens has a generally planar profile, a slightly curved profile, an elliptical curved profile, a spherical curved profiled, or an aspheric curved profile, or combinations thereof.
13. A head-up display system as claimed in claim 7, wherein the first index of refraction is equal to or approximately equal to the second index of refraction.
14. A head-up display system as claimed in claim 7, wherein the first index of refraction is sufficiently different from the second index of refraction to provide magnification of an image transmitted through the lens.
15. A head-up display system as claimed in claim 7, further comprising:
- a first layer and a second layer, wherein the first layer and the second layer are at least partially transparent;
- wherein the lens and the filler medium are disposed between the first layer and the second layer.
16. A head-up display system as claimed in claim 7, further comprising:
- a first layer and a second layer, wherein the first layer and the second layer are at least partially transparent;
- wherein the lens and the filler medium are disposed between the first layer and the second layer, and the first layer or the second layer, or combinations thereof, have a curvature to provide magnification of an image projected through the lens, wherein the curvature comprises an inner surface of the first layer, an outer surface of the first layer, an inner surface of the second layer, or an outer surface of the second layer, or combinations thereof.
17. A near-to-eye display system, comprising:
- a projector module capable of emitting a projected image; and
- an optical relay onto which the scanned beam is projected from a first side of the optical relay to allow a viewer to view the projected image through the optical relay wherein the projected image is displayed on another side of the optical relay;
- wherein the optical relay comprises:
- a lens having an least partially reflective coating and a first index of refraction, the lens comprising a Fresnel lens, a diffractive lens, or a holographic lens, or combinations thereof, wherein the at least partially reflective coating is a neutral density filter;
- a filler medium having a second index of refraction and being disposed adjacent to the lens, wherein at least one of the lens or the filler medium, or combinations thereof, is at least partially transparent;
- a polarizing beam splitter disposed between the integrated photonics module and the optical relay; and
- a retarder or a beam splitter, or combinations thereof, disposed proximate to the lens.
18. A near-to-eye display system as claimed in claim 17, further comprising:
- a first layer and a second layer, wherein the first layer and the second layer are at least partially transparent;
- wherein the lens and the filler medium are disposed between the first layer and the second layer, and the first layer or the second layer, or combinations thereof, have a curvature to provide magnification of an image transmitted through the optical relay, wherein the curvature comprises an inner surface of the first layer, an outer surface of the first layer, an inner surface of the second layer, or an outer surface of the second layer, or combinations thereof.
19. A near-to-eye display system as claimed in claim 17, wherein a distance between the integrated photonics module and the optical relay is adjustable to allow adjustment of distance at which the projected image appears from the viewer's eye.
20-25. (canceled)
Type: Application
Filed: Aug 19, 2008
Publication Date: Feb 25, 2010
Applicant: MICROVISION, INC. (Redmond, WA)
Inventors: Karlton D. Powell (Lake Stevens, WA), Mark O. Freeman (Snohomish, WA), David Scott Wright (Bellevue, WA)
Application Number: 12/194,466
International Classification: G02B 27/01 (20060101); G02B 27/10 (20060101); G02B 27/42 (20060101);