Software Technology for “Head-mounted Augmented Reality Display”

Metaverse – Ian E. McDowall, Mark T. Bolas, Fakespace Labs Inc

Abstract for “Head-mounted Augmented Reality Display”

The inventions include “Compact, low-mass, augmented and fully virtual head-mounted display designs.” Displays of this nature are placed between the eyes and the main optical component of the head-mounted display. These displays can also be used to support augmented reality displays, which allow the user to see the real world and the virtual image on the display. Semi-transparent displays are those that emit circularly polarized light, or light from only one surface. The view from the eyes is also obscured by semi-transparent displays.

Background for “Head-mounted Augmented Reality Display”

“A Ferrand Pancake Window is one way to mount head-mounted virtual reality displays. As described in U.S. Pat. No. No. FIG. 1. This design recognizes that a curved mirror can provide wide viewing angles and a short focal length. The pancake window can also be made semi-transparent by using a 45-degree 50% reflective mirror, additional optics, and additional optics. This creates a real image of where the pancake is concentrated. To create a virtual image from the eye side, the optical path for the pancake window device uses circular-polarization-based mirror bounces. The optical path is light that travels away from the eye.

The devices and methods below allow for an augmented/virtual reality head mounted display that is placed between the user’s eyes and a curved reflector. The head-mounted display system allows heavy optical components to be placed closer to the user. This allows for a smaller display that provides a wider field of view. The shape of the curved reflector can be aspherical, spherical, or both.

An augmented reality display consists of a curved reflector, an optical stack, and a user’s eyes. The optical stack is composed of a display and a quarter wave plate. It also includes a reflective polarizer.

An augmented or virtual-reality display could include multiple displays at different distances from the eye, while still being between the eye and the reflective optics. Multiple displays at different distances allow the user to perceive virtual images from different distances. This configuration resolves the visual conflict between vergence and accommodation. Visually, displays that address both accommodation AND vergence are deemed “correct”.

“An augmented, virtual reality display could also include one or two elements, such as a liquid display that optically occludes all or part the real world on request. Electronically, you can turn on or off this real-world occlusion. This configuration allows partial occlusion of real world. For example, virtual objects located at the angular position of the user’s view can be dimmed. You can create a seamless mixed-reality environment by carefully manipulating the relative brightness between the real and virtual worlds.

“FIGS. The augmented reality head-mounted LCD 10 is illustrated in 2, 3, and 4. Display 10 contains an optical element and display stack 12, which are located between the user’s eyes 1 and 13 to allow the user to simultaneously see a portion light 5 that has been reflected or emitted from the real world, such as mascot 3, as well as light 15 that has come from an emissive display 14. Any suitable curved reflector with a spherical, aspherical, or compound shape may be used for reflection 13. Emissive display 14 emits circularly-polarized light 15 towards the user’s eye. Any suitable emissive display that emits light from its surface or from within a thin sheet of material less than a few micrometers thick can be called an “emissive display”. This display can be constructed using organic light emitting devices (OLED), light-emitting diodes(LED), or any other suitable method to produce a plurality light emitting elements. These elements can be placed as transparent elements on a substantially continuous surface, such as an edge-illuminated component and a liquid crystal device (LCD). The transparent or semi-transparent Emissive Display 14 can also be transparent. This transparency can either be a general passing of light, or a small number of non transparent elements placed on a transparent substrate. However, the overall effect is that light passes through the display.

“FIG. 3. This is a cross-section of the optical elements in display system 10. It shows how emitted light 15 passes through quarter wave plate 16 and becomes linearly polarized light 17. The reflective polarizer 18 on element 20 reflects polarized light 17. Polarized light 17 is then reflected off the reflective polarizer 18. Reflected polarized 17R passes through quarter-wave 16 and is circularly transformed to have the same state of polarization as the original emissive light 15. The emissive display then receives the reflected and circularly polarized 21-watt light. Secondary light 15S, which is reflected from reflector 13, then passes through emissive 14 and the circularly polarized and reflected light 21. They have the same circular Polarization and can be distinguished because they both traverse quarter-wave plate 16 twice. Secondary light 15S and the reflected and circularly polarized 21 light then reflect from surface 13A. Some portion, if not all, of this light is reflected back as light 22. Idealized reflector 13. Reflector 13 is actually made to meet manufacturing constraints and visual performance goals.

Reflected light 13 shows that the handedness of light 15S (and 21) is reversed. Light 22 now passes through emissive 14 and quarter-wave 16 and becomes light 23, with a linear Polarization orthogonal light 17. Light 23 passes through reflective 18 and optical element 20, and can be viewed by eye 1. The light that passes through the reflective polarizer 18 and optical element 20 is light that has come from the display. It has also been reflected by the reflector. You can adjust the proportion of light that is reflected by the mirror surface. This parameter allows you to adjust the brightness of the reflected display 14.

An optional absorbing linear, linear polarizer (polarizer 19) may be added to allow light with linear polarization associated to the light 23 to pass through. It absorbs any light that is largely reflected from the eyes or entered the optics from the eye side. Optional final linear polarizer, such as polarizer 19, is available. Final absorbing polarizer 19 is not required if reflective polarizer 18 has dark surfaces with protective layers.

“The thickness of quarter-wave plates 16, reflective polarizer 18, and optical element 20 are arbitrary. Ideally, some or all of these should be made as thin sheets, especially quarter-wave plates 16. Quarter-wave plate 16 will have a significantly thicker thickness so that the light coming from the front and back of the display is focused in slightly different areas from the user’s perspective. This is not an issue, as quarter-wave film can be very thin. The thickness may also be beneficial to improve the visual experience of the display system.

Display system 10, which emits linearly polarized light to the eye, can have the contrast ratio slightly improved by filtering light that reflects back from the eye 1 into the optical system. You can do this by adding a quarter wave plate to the final linear absorber polarizer. The linearly polarized light that passes towards the eyes is circularly polarized. However, the reflected light from the eyes will have some reversed handedness. This makes it orthogonally polarized relative the linear absorbing polarizer 19. It is then absorbed.

To block out light from the real world, an optional element like LCD element 24 can be added to or secured to reflector 13. You can either attach LCD element 24 to reflector 13, or you could separate it from it. An LCD element that is suitable for use is made up of multiple pixels that can be electronically controlled to change their transparency or opaque states. The LCD element 24 can be made up of polarizers and liquid crystal material. A quarter-wave plate is ideal for allowing the designer to control the light that passes through the element. This allows light 5 from the outside world to pass through the element 24 and be absorbed by the LCD 24 polarizers or emerge through the element 24 with circular polarization, indistinguishable to light 22.

Quarter-wave plates, such as 16 quarter-wave plates, are used in this description. An emissive display is a quarter-waveplate that converts linearly-polarized light into substantially circularly-polarized light. This plate may also be called an achromatic half-wave plate. A quarter-waveplate that is suitable can perform as a substantially achromatic half-wave plate across the entire wavelength range or behaves substantially like a quarter wave plate for the wavelengths of the display or the ones emitted. If a display has primary colors of 625 nm and 460 nm respectively, the quarter-wave plate could be made substantially achromatic (i.e. With some tolerance, it could be used to produce a quarter-wave retardance (+/?. Some tolerance) in the ranges of 455 nm to 630nm or 505 nm to 515nm and 620 nm to 630nm. The performance of the element can be either undefined, relaxed, or specified to cause a different degree of retardation in other parts of the visible spectrum. The performance of quarter-wave plates will be determined over a cone angle that will be chosen based on emission cone 26 in FIG. 3. This description of quarter-wave plates means a quarter wave plate that performs the function over the wavelengths in interest.

A reflective polarizer, such as the 18-inch reflective polarizer, has the property to reflect one state of polarization and reflect orthogonally polarized sunlight. An appropriate polarizer could be a wire-grid polarizer, such as the ones made by Moxtek. They may also be used with a plastic film material made by 3M or others with similar properties. Or they may be used with other means that have substantially the same property. It acts substantially as a mirror to one state of polarization and as semi-transparent windows to orthogonallypolarized light. Combining the disclosed wire grid polarizer with a quarter wave plate creates an element that substantially reflects one state in which circularly polarized sunlight is transmitted and substantially reflecting another. You can replace this pair with any single element that has the same properties in relation to circularly-polarized light. For example, cholesteric liquid crystals have been used to make such elements. These elements can also be made using nanofabrication techniques that create chiral metamaterials and chiral mirrors. These reflect one circular polarization status and transmit the other for a range of wavelengths within the visible spectrum or for selected wavelengths. A linear polarizer does not need to be used if the majority, or substantially all, of the light from an emitting display is emitted towards the concave mirror or reflector. 4 below. A linear polarizer, as shown in FIG. 4, is necessary when the majority, or substantially all, of the light from an emitting display is directed toward the user’s eyes. 1.”

“Display system 30 in FIG. 2. Creates virtual images 31A-31B and 31C at various apparent distances from user?s eye 1 using the illustrated pencils for light from displays 32, 34, and 36. Circularly polarized light is emitted from the eye side, 32E, 34E, and 36E respectively of emissive display 32, 34, 36, which are each oriented in different distances to user’s eyes 1, 33A, 35A, and 37A respectively. Also, different distances form reflective surface 38A at distances 33B 35B and 37B, respectively, to create different virtual images 31A-31B and 31C at various apparent distances from user?s eye. The light from emissive displays has a wide cone angle. These illustrations show a pencil of the emitted light, which is the light that the display emits.

As mentioned above, the emitted light from each display is reflected off reflective polarizer 40 on element 41 and becomes linearly polarized. Reflective polarizer 40 is used to reflect the polarized light. The reflected polarized radiation then passes through element 41. It is circularly polarized so that it has the same polarization as the original light from each emissive device. Each emissive display 32, 34, and 36 then receives the reflected and circularly-polarized light. Therefore, light 42, which is directed toward reflector 38, is composed of light from all three displays 32-34 and 36 that have reflected off surface 38A. Light 42 illustrates all of the light from each display. It is circularly polarized light, such as light 44 which has traversed quarter wave plate 39 twice and was reflected from reflective-polarizer 40), and they have the same circular Polarization. They are therefore indistinguishable. Circularly polarized light 42 is then reflected from surface 38A, and some (perhaps all) of it is reflected as light 47. Light 44 is also reflected as light 45. This applies to all three emissive displays.

“Upon reflection at surface38A, the handedness in light 42 and 44 are reversed in light 45 or 45 respectively. Reflector surface 38A light, such as light 45 or 45, now passes through emissive display 36, 34 and 32. Quarter-wave plate 39 also sees it. This pass has a linear phase that is orthogonal to the original light passing through quarter wave plate 39. Reflective polarizer 39 is now used to reflect light 45 and 45. It can be seen in the eye-box 48 by using user’s eyes 1 and 40.

“Emissive display 32, 34 and 36 have been displaced so that they create different virtual images as per the user’s perception at eye-box 48. These displays are presented parallel to one another, but you can tilt the display surfaces to tilt the planes. The displays can be coated with anti-reflection material or filled with transparent media that indexes better than air to reduce inter reflections.

“In a simpler display system light is projected from one side of a transparent display. It travels through transparent materials such as air, plastic or glass to reach a partially reflective concave mirror surface. Some light is lost because the light is partially reflected by the mirror surface. The reflected light travels through the glass or air towards the display, and then back to the eye of the viewer.

“Virtual display 50” of FIGS. Display 52 is an emissive display that emits light 55 from one surface or face, generally transparent. 6., 7 and 8 are oriented with display 52 between the emissive 52S and the user’s eyes 1. The interior surface 56A is the mirror shell 56, and light 55 then meets it. Mirror 56 is shown as having thickness and the actual reflective/transmissive coating 58 is typically applied on the inside or interior surface 56A which affords some protection to the coating if the outside or exterior surface of 56B is the external surface of the display system. Light 55 impinges on reflective surface 58 and some portion of the light 55R; as determined by the reflective/transmissive characteristics 58X of reflective surface coating 58 is reflected back to the user’s eye 1. Display 52 is partially or completely transmissive so 55R reflects back. Optionally, reflector light 55R can pass through the occluding 54. This may create a light blocking pattern consisting of small opaque shapes 59X like pattern 59. These shapes block any light emanating from display 52 in the direction of your eye. To account for parallax between emissive elements and users eyes, the position of opaque shapes can be adjusted. On the eye side, the thin LCD could display the pattern of occluding forms. Any linear elements, such as lines or other combinations of shapes, can be used to block light in the light blocking pattern 59. Any suitable halftone pattern can also be used to block light from the pattern of opaque shapes.

Reflective coatings, such as 38A or 58A, can be applied inside or outside the curvilinear shells like shell 56. Shell 56’s thickness can be adjusted to suit the user’s prescription. A reflective coating or surface can be wavelength-tuned to match the spectral characteristics or displays. By tuning the ratio one can achieve a higher relative brightness by using less light. The reflector shells can also be made as Fresnel-type reflectors. The reflector’s surfaces should have concentric facets.

“Any display system 10, 30, or 50 can include one or more optical elements as shown in FIGS. 6, 7, and 8. Linear polarizer 60, a quarter-waveplate 62 and a linear polarizer 60 external optical elements properly polarize light coming from outside display systems 10, 30, 50 or 50. They also impinge on light like light 53 in FIG. Linear polarizer 60 will allow light from outside to pass through it, while quarter-wave plate 662 will permit light from outside to be polarized. This means that light 53X from outside the display system 50 will have the same circular polarization effect as light 55R reflecting from the interior of the mirror. The optical systems can be transmitted in this way.

To allow light to enter the display and reduce light escaping through the reflector, polarization elements can be placed on the exterior or outside surface of the Augmented Reality Display. To align the polarization element on the outside, a curved reflector 56 must be placed between the elements and the eye. The curved reflector reflects light from the optical system between the user’s eyes and the reflective mirror coating. Light 55X, for example, must pass through quarter wave plate 62. This will transform it into linearly polarized light 55L, which will then be absorbed by the external linear polarizer 60. This means that very little light is visible from this side of the system. The same principle applies to FIGS. 3, 4, and 5.

“Similarly, augmented reality displays may use mirrors and partially transparent/partially reflecting mirrors. These optical elements may be implemented either with coatings such that their reflective/transmissive properties behave as substantially broadband devices in the visible spectrum over which the display illumination is relevant or may be constructed using coatings which are selective in terms of the wavelengths (technically selected ranges of wavelengths) of light where the particular reflective/transmissive behavior is tailored to match in some way the wavelength ranges emitted by the display.”

“Where concave mirrors are present, it is to be understood that the specific sag and form of the surface as well as the optical properties of that surface could be selected to meet particular performance requirements. The surface can be simple, spherical, aspherical, or free-form optical. The designer would choose the best shape for the product design based on the performance requirements, such as field, manufacturing method, aesthetic requirements, and aesthetic requirements. You can make a mirrored or reflective surface in a concave or without optical power. Or, you can have a prescription surface. You can choose the surface and material that best suits your vision.

A display panel or emissive screen emits light that is substantially circularly-polarized and has a particular handedness. The circular polarizer transforms the light from the display into linear polarization. A mirror reflects the linearly polarized light and passes it through. Linearly polarized light then is reflected back to the display. It passes through the quarter wave plate again and is circularly-polarized with the same handedness. The light then passes through the transparent display panel and emerges circularly polarized with an individualized handedness. The light travels through air, plastic or glass to reach a concave mirror surface. Some light passes through the mirror and is lost. The other light is reflected, and the reverse of circular polarization occurs. The light passes through the display which is mostly transparent, and then through the quarter-wave plate linearly Polarizing the light with an achromatic linear state which is perpendicular the original linear state of the light at the surface. Since the linear polarizer only reflects one linear state, the light is transmitted through it. Optionally, the light passes through an absorbent type polarizer before emerging from the display. The displays can also be curved into a cylindrical shape. Emissive displays such as displays 14, 32, 34, 36 and 52 may be any suitable light emitting display as discussed above with reflective/absorbing/interference creating/nano structures to force the light to emanate from one side.”

An OLED display may have light emitting mainly from one side of the substrate. OLED displays can be made using patterns that are similar to a beam splitter with dots instead of dots. Patterns of dots are more beneficial for the purposes described here. They can be applied to the OLED after it has been fabricated by either printing on its back or laminating the OLED to glass substrate with a pattern. You can further optimize the pattern for visual viewing. Because there is no angle between the light coming from the pixel and the dot, they can be very small in the middle of the field of vision. The slight thickness of the light emitting pixels and the blocking/reflecting elements means that the eye can see?around? in the display’s periphery. The blocking element should be radially offset and optimally elliptical. They should also be slightly larger in size. Also, these blocking elements must be reflective-free and absorbing. Secondary reflections can degrade the display’s contrast ratio. While reflective can work, absorbing is preferable.

“In each description of the system, an emissive transparent screen may be replaced by a stack of two or three such displays that are separated by glass, air or another transparent medium. This allows the optical system and display to position the images from each panel at different distances from the viewer.

“If the curved mirror is partially transparent to allow the user to see both the real world as well as the images created by display and optical systems simultaneously, it might be beneficial to add a way to polarize the inbound light in a controlled manner. You can do this by adding a liquid crystal panel with a polarizer to the outside but not on the inside. This allows a computer control the polarization from the real world. If the light is circularly polarized, it can be passed through an optional wide-band achromatic quarter wave plate. The system can present the virtual images together with the real world, although the real world may be spatially reduced if necessary. You may also find liquid crystal devices that can directly transmit the transmitted light with either right- or left-handed polarization. In this case, the function of the quarter wave plate will be incorporated into the computer-controlled device. This section of the system should be bent and manufactured to fit the shape of the outer reflector.

The preferred embodiments of these devices and methods were described with reference to the environment they were created, but they do not represent the entire principles of the inventions. To reap the benefits of each element, the elements of different embodiments can be combined with other species. The various beneficial features can be used in combinations or as a single embodiment. You can create other embodiments or configurations without departing from both the spirit and scope of the claims.

Summary for “Head-mounted Augmented Reality Display”

“A Ferrand Pancake Window is one way to mount head-mounted virtual reality displays. As described in U.S. Pat. No. No. FIG. 1. This design recognizes that a curved mirror can provide wide viewing angles and a short focal length. The pancake window can also be made semi-transparent by using a 45-degree 50% reflective mirror, additional optics, and additional optics. This creates a real image of where the pancake is concentrated. To create a virtual image from the eye side, the optical path for the pancake window device uses circular-polarization-based mirror bounces. The optical path is light that travels away from the eye.

The devices and methods below allow for an augmented/virtual reality head mounted display that is placed between the user’s eyes and a curved reflector. The head-mounted display system allows heavy optical components to be placed closer to the user. This allows for a smaller display that provides a wider field of view. The shape of the curved reflector can be aspherical, spherical, or both.

An augmented reality display consists of a curved reflector, an optical stack, and a user’s eyes. The optical stack is composed of a display and a quarter wave plate. It also includes a reflective polarizer.

An augmented or virtual-reality display could include multiple displays at different distances from the eye, while still being between the eye and the reflective optics. Multiple displays at different distances allow the user to perceive virtual images from different distances. This configuration resolves the visual conflict between vergence and accommodation. Visually, displays that address both accommodation AND vergence are deemed “correct”.

“An augmented, virtual reality display could also include one or two elements, such as a liquid display that optically occludes all or part the real world on request. Electronically, you can turn on or off this real-world occlusion. This configuration allows partial occlusion of real world. For example, virtual objects located at the angular position of the user’s view can be dimmed. You can create a seamless mixed-reality environment by carefully manipulating the relative brightness between the real and virtual worlds.

“FIGS. The augmented reality head-mounted LCD 10 is illustrated in 2, 3, and 4. Display 10 contains an optical element and display stack 12, which are located between the user’s eyes 1 and 13 to allow the user to simultaneously see a portion light 5 that has been reflected or emitted from the real world, such as mascot 3, as well as light 15 that has come from an emissive display 14. Any suitable curved reflector with a spherical, aspherical, or compound shape may be used for reflection 13. Emissive display 14 emits circularly-polarized light 15 towards the user’s eye. Any suitable emissive display that emits light from its surface or from within a thin sheet of material less than a few micrometers thick can be called an “emissive display”. This display can be constructed using organic light emitting devices (OLED), light-emitting diodes(LED), or any other suitable method to produce a plurality light emitting elements. These elements can be placed as transparent elements on a substantially continuous surface, such as an edge-illuminated component and a liquid crystal device (LCD). The transparent or semi-transparent Emissive Display 14 can also be transparent. This transparency can either be a general passing of light, or a small number of non transparent elements placed on a transparent substrate. However, the overall effect is that light passes through the display.

“FIG. 3. This is a cross-section of the optical elements in display system 10. It shows how emitted light 15 passes through quarter wave plate 16 and becomes linearly polarized light 17. The reflective polarizer 18 on element 20 reflects polarized light 17. Polarized light 17 is then reflected off the reflective polarizer 18. Reflected polarized 17R passes through quarter-wave 16 and is circularly transformed to have the same state of polarization as the original emissive light 15. The emissive display then receives the reflected and circularly polarized 21-watt light. Secondary light 15S, which is reflected from reflector 13, then passes through emissive 14 and the circularly polarized and reflected light 21. They have the same circular Polarization and can be distinguished because they both traverse quarter-wave plate 16 twice. Secondary light 15S and the reflected and circularly polarized 21 light then reflect from surface 13A. Some portion, if not all, of this light is reflected back as light 22. Idealized reflector 13. Reflector 13 is actually made to meet manufacturing constraints and visual performance goals.

Reflected light 13 shows that the handedness of light 15S (and 21) is reversed. Light 22 now passes through emissive 14 and quarter-wave 16 and becomes light 23, with a linear Polarization orthogonal light 17. Light 23 passes through reflective 18 and optical element 20, and can be viewed by eye 1. The light that passes through the reflective polarizer 18 and optical element 20 is light that has come from the display. It has also been reflected by the reflector. You can adjust the proportion of light that is reflected by the mirror surface. This parameter allows you to adjust the brightness of the reflected display 14.

An optional absorbing linear, linear polarizer (polarizer 19) may be added to allow light with linear polarization associated to the light 23 to pass through. It absorbs any light that is largely reflected from the eyes or entered the optics from the eye side. Optional final linear polarizer, such as polarizer 19, is available. Final absorbing polarizer 19 is not required if reflective polarizer 18 has dark surfaces with protective layers.

“The thickness of quarter-wave plates 16, reflective polarizer 18, and optical element 20 are arbitrary. Ideally, some or all of these should be made as thin sheets, especially quarter-wave plates 16. Quarter-wave plate 16 will have a significantly thicker thickness so that the light coming from the front and back of the display is focused in slightly different areas from the user’s perspective. This is not an issue, as quarter-wave film can be very thin. The thickness may also be beneficial to improve the visual experience of the display system.

Display system 10, which emits linearly polarized light to the eye, can have the contrast ratio slightly improved by filtering light that reflects back from the eye 1 into the optical system. You can do this by adding a quarter wave plate to the final linear absorber polarizer. The linearly polarized light that passes towards the eyes is circularly polarized. However, the reflected light from the eyes will have some reversed handedness. This makes it orthogonally polarized relative the linear absorbing polarizer 19. It is then absorbed.

To block out light from the real world, an optional element like LCD element 24 can be added to or secured to reflector 13. You can either attach LCD element 24 to reflector 13, or you could separate it from it. An LCD element that is suitable for use is made up of multiple pixels that can be electronically controlled to change their transparency or opaque states. The LCD element 24 can be made up of polarizers and liquid crystal material. A quarter-wave plate is ideal for allowing the designer to control the light that passes through the element. This allows light 5 from the outside world to pass through the element 24 and be absorbed by the LCD 24 polarizers or emerge through the element 24 with circular polarization, indistinguishable to light 22.

Quarter-wave plates, such as 16 quarter-wave plates, are used in this description. An emissive display is a quarter-waveplate that converts linearly-polarized light into substantially circularly-polarized light. This plate may also be called an achromatic half-wave plate. A quarter-waveplate that is suitable can perform as a substantially achromatic half-wave plate across the entire wavelength range or behaves substantially like a quarter wave plate for the wavelengths of the display or the ones emitted. If a display has primary colors of 625 nm and 460 nm respectively, the quarter-wave plate could be made substantially achromatic (i.e. With some tolerance, it could be used to produce a quarter-wave retardance (+/?. Some tolerance) in the ranges of 455 nm to 630nm or 505 nm to 515nm and 620 nm to 630nm. The performance of the element can be either undefined, relaxed, or specified to cause a different degree of retardation in other parts of the visible spectrum. The performance of quarter-wave plates will be determined over a cone angle that will be chosen based on emission cone 26 in FIG. 3. This description of quarter-wave plates means a quarter wave plate that performs the function over the wavelengths in interest.

A reflective polarizer, such as the 18-inch reflective polarizer, has the property to reflect one state of polarization and reflect orthogonally polarized sunlight. An appropriate polarizer could be a wire-grid polarizer, such as the ones made by Moxtek. They may also be used with a plastic film material made by 3M or others with similar properties. Or they may be used with other means that have substantially the same property. It acts substantially as a mirror to one state of polarization and as semi-transparent windows to orthogonallypolarized light. Combining the disclosed wire grid polarizer with a quarter wave plate creates an element that substantially reflects one state in which circularly polarized sunlight is transmitted and substantially reflecting another. You can replace this pair with any single element that has the same properties in relation to circularly-polarized light. For example, cholesteric liquid crystals have been used to make such elements. These elements can also be made using nanofabrication techniques that create chiral metamaterials and chiral mirrors. These reflect one circular polarization status and transmit the other for a range of wavelengths within the visible spectrum or for selected wavelengths. A linear polarizer does not need to be used if the majority, or substantially all, of the light from an emitting display is emitted towards the concave mirror or reflector. 4 below. A linear polarizer, as shown in FIG. 4, is necessary when the majority, or substantially all, of the light from an emitting display is directed toward the user’s eyes. 1.”

“Display system 30 in FIG. 2. Creates virtual images 31A-31B and 31C at various apparent distances from user?s eye 1 using the illustrated pencils for light from displays 32, 34, and 36. Circularly polarized light is emitted from the eye side, 32E, 34E, and 36E respectively of emissive display 32, 34, 36, which are each oriented in different distances to user’s eyes 1, 33A, 35A, and 37A respectively. Also, different distances form reflective surface 38A at distances 33B 35B and 37B, respectively, to create different virtual images 31A-31B and 31C at various apparent distances from user?s eye. The light from emissive displays has a wide cone angle. These illustrations show a pencil of the emitted light, which is the light that the display emits.

As mentioned above, the emitted light from each display is reflected off reflective polarizer 40 on element 41 and becomes linearly polarized. Reflective polarizer 40 is used to reflect the polarized light. The reflected polarized radiation then passes through element 41. It is circularly polarized so that it has the same polarization as the original light from each emissive device. Each emissive display 32, 34, and 36 then receives the reflected and circularly-polarized light. Therefore, light 42, which is directed toward reflector 38, is composed of light from all three displays 32-34 and 36 that have reflected off surface 38A. Light 42 illustrates all of the light from each display. It is circularly polarized light, such as light 44 which has traversed quarter wave plate 39 twice and was reflected from reflective-polarizer 40), and they have the same circular Polarization. They are therefore indistinguishable. Circularly polarized light 42 is then reflected from surface 38A, and some (perhaps all) of it is reflected as light 47. Light 44 is also reflected as light 45. This applies to all three emissive displays.

“Upon reflection at surface38A, the handedness in light 42 and 44 are reversed in light 45 or 45 respectively. Reflector surface 38A light, such as light 45 or 45, now passes through emissive display 36, 34 and 32. Quarter-wave plate 39 also sees it. This pass has a linear phase that is orthogonal to the original light passing through quarter wave plate 39. Reflective polarizer 39 is now used to reflect light 45 and 45. It can be seen in the eye-box 48 by using user’s eyes 1 and 40.

“Emissive display 32, 34 and 36 have been displaced so that they create different virtual images as per the user’s perception at eye-box 48. These displays are presented parallel to one another, but you can tilt the display surfaces to tilt the planes. The displays can be coated with anti-reflection material or filled with transparent media that indexes better than air to reduce inter reflections.

“In a simpler display system light is projected from one side of a transparent display. It travels through transparent materials such as air, plastic or glass to reach a partially reflective concave mirror surface. Some light is lost because the light is partially reflected by the mirror surface. The reflected light travels through the glass or air towards the display, and then back to the eye of the viewer.

“Virtual display 50” of FIGS. Display 52 is an emissive display that emits light 55 from one surface or face, generally transparent. 6., 7 and 8 are oriented with display 52 between the emissive 52S and the user’s eyes 1. The interior surface 56A is the mirror shell 56, and light 55 then meets it. Mirror 56 is shown as having thickness and the actual reflective/transmissive coating 58 is typically applied on the inside or interior surface 56A which affords some protection to the coating if the outside or exterior surface of 56B is the external surface of the display system. Light 55 impinges on reflective surface 58 and some portion of the light 55R; as determined by the reflective/transmissive characteristics 58X of reflective surface coating 58 is reflected back to the user’s eye 1. Display 52 is partially or completely transmissive so 55R reflects back. Optionally, reflector light 55R can pass through the occluding 54. This may create a light blocking pattern consisting of small opaque shapes 59X like pattern 59. These shapes block any light emanating from display 52 in the direction of your eye. To account for parallax between emissive elements and users eyes, the position of opaque shapes can be adjusted. On the eye side, the thin LCD could display the pattern of occluding forms. Any linear elements, such as lines or other combinations of shapes, can be used to block light in the light blocking pattern 59. Any suitable halftone pattern can also be used to block light from the pattern of opaque shapes.

Reflective coatings, such as 38A or 58A, can be applied inside or outside the curvilinear shells like shell 56. Shell 56’s thickness can be adjusted to suit the user’s prescription. A reflective coating or surface can be wavelength-tuned to match the spectral characteristics or displays. By tuning the ratio one can achieve a higher relative brightness by using less light. The reflector shells can also be made as Fresnel-type reflectors. The reflector’s surfaces should have concentric facets.

“Any display system 10, 30, or 50 can include one or more optical elements as shown in FIGS. 6, 7, and 8. Linear polarizer 60, a quarter-waveplate 62 and a linear polarizer 60 external optical elements properly polarize light coming from outside display systems 10, 30, 50 or 50. They also impinge on light like light 53 in FIG. Linear polarizer 60 will allow light from outside to pass through it, while quarter-wave plate 662 will permit light from outside to be polarized. This means that light 53X from outside the display system 50 will have the same circular polarization effect as light 55R reflecting from the interior of the mirror. The optical systems can be transmitted in this way.

To allow light to enter the display and reduce light escaping through the reflector, polarization elements can be placed on the exterior or outside surface of the Augmented Reality Display. To align the polarization element on the outside, a curved reflector 56 must be placed between the elements and the eye. The curved reflector reflects light from the optical system between the user’s eyes and the reflective mirror coating. Light 55X, for example, must pass through quarter wave plate 62. This will transform it into linearly polarized light 55L, which will then be absorbed by the external linear polarizer 60. This means that very little light is visible from this side of the system. The same principle applies to FIGS. 3, 4, and 5.

“Similarly, augmented reality displays may use mirrors and partially transparent/partially reflecting mirrors. These optical elements may be implemented either with coatings such that their reflective/transmissive properties behave as substantially broadband devices in the visible spectrum over which the display illumination is relevant or may be constructed using coatings which are selective in terms of the wavelengths (technically selected ranges of wavelengths) of light where the particular reflective/transmissive behavior is tailored to match in some way the wavelength ranges emitted by the display.”

“Where concave mirrors are present, it is to be understood that the specific sag and form of the surface as well as the optical properties of that surface could be selected to meet particular performance requirements. The surface can be simple, spherical, aspherical, or free-form optical. The designer would choose the best shape for the product design based on the performance requirements, such as field, manufacturing method, aesthetic requirements, and aesthetic requirements. You can make a mirrored or reflective surface in a concave or without optical power. Or, you can have a prescription surface. You can choose the surface and material that best suits your vision.

A display panel or emissive screen emits light that is substantially circularly-polarized and has a particular handedness. The circular polarizer transforms the light from the display into linear polarization. A mirror reflects the linearly polarized light and passes it through. Linearly polarized light then is reflected back to the display. It passes through the quarter wave plate again and is circularly-polarized with the same handedness. The light then passes through the transparent display panel and emerges circularly polarized with an individualized handedness. The light travels through air, plastic or glass to reach a concave mirror surface. Some light passes through the mirror and is lost. The other light is reflected, and the reverse of circular polarization occurs. The light passes through the display which is mostly transparent, and then through the quarter-wave plate linearly Polarizing the light with an achromatic linear state which is perpendicular the original linear state of the light at the surface. Since the linear polarizer only reflects one linear state, the light is transmitted through it. Optionally, the light passes through an absorbent type polarizer before emerging from the display. The displays can also be curved into a cylindrical shape. Emissive displays such as displays 14, 32, 34, 36 and 52 may be any suitable light emitting display as discussed above with reflective/absorbing/interference creating/nano structures to force the light to emanate from one side.”

An OLED display may have light emitting mainly from one side of the substrate. OLED displays can be made using patterns that are similar to a beam splitter with dots instead of dots. Patterns of dots are more beneficial for the purposes described here. They can be applied to the OLED after it has been fabricated by either printing on its back or laminating the OLED to glass substrate with a pattern. You can further optimize the pattern for visual viewing. Because there is no angle between the light coming from the pixel and the dot, they can be very small in the middle of the field of vision. The slight thickness of the light emitting pixels and the blocking/reflecting elements means that the eye can see?around? in the display’s periphery. The blocking element should be radially offset and optimally elliptical. They should also be slightly larger in size. Also, these blocking elements must be reflective-free and absorbing. Secondary reflections can degrade the display’s contrast ratio. While reflective can work, absorbing is preferable.

“In each description of the system, an emissive transparent screen may be replaced by a stack of two or three such displays that are separated by glass, air or another transparent medium. This allows the optical system and display to position the images from each panel at different distances from the viewer.

“If the curved mirror is partially transparent to allow the user to see both the real world as well as the images created by display and optical systems simultaneously, it might be beneficial to add a way to polarize the inbound light in a controlled manner. You can do this by adding a liquid crystal panel with a polarizer to the outside but not on the inside. This allows a computer control the polarization from the real world. If the light is circularly polarized, it can be passed through an optional wide-band achromatic quarter wave plate. The system can present the virtual images together with the real world, although the real world may be spatially reduced if necessary. You may also find liquid crystal devices that can directly transmit the transmitted light with either right- or left-handed polarization. In this case, the function of the quarter wave plate will be incorporated into the computer-controlled device. This section of the system should be bent and manufactured to fit the shape of the outer reflector.

The preferred embodiments of these devices and methods were described with reference to the environment they were created, but they do not represent the entire principles of the inventions. To reap the benefits of each element, the elements of different embodiments can be combined with other species. The various beneficial features can be used in combinations or as a single embodiment. You can create other embodiments or configurations without departing from both the spirit and scope of the claims.

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How to Search for Patents

A patent search is the first step to getting your patent. You can do a google patent search or do a USPTO search. Patent-pending is the term for the product that has been covered by the patent application. You can search the public pair to find the patent application. After the patent office approves your application, you will be able to do a patent number look to locate the patent issued. Your product is now patentable. You can also use the USPTO search engine. See below for details. You can get help from a patent lawyer. Patents in the United States are granted by the US trademark and patent office or the United States Patent and Trademark office. This office also reviews trademark applications.

Are you interested in similar patents? These are the steps to follow:

1. Brainstorm terms to describe your invention, based on its purpose, composition, or use.

Write down a brief, but precise description of the invention. Don’t use generic terms such as “device”, “process,” or “system”. Consider synonyms for the terms you chose initially. Next, take note of important technical terms as well as keywords.

Use the questions below to help you identify keywords or concepts.

• What is the purpose of the invention Is it a utilitarian device or an ornamental design?
• Is invention a way to create something or perform a function? Is it a product?
• What is the composition and function of the invention? What is the physical composition of the invention?
• What’s the purpose of the invention
• What are the technical terms and keywords used to describe an invention’s nature? A technical dictionary can help you locate the right terms.

2. These terms will allow you to search for relevant Cooperative Patent Classifications at Classification Search Tool. If you are unable to find the right classification for your invention, scan through the classification’s class Schemas (class schedules) and try again. If you don’t get any results from the Classification Text Search, you might consider substituting your words to describe your invention with synonyms.

3. Check the CPC Classification Definition for confirmation of the CPC classification you found. If the selected classification title has a blue box with a “D” at its left, the hyperlink will take you to a CPC classification description. CPC classification definitions will help you determine the applicable classification’s scope so that you can choose the most relevant. These definitions may also include search tips or other suggestions that could be helpful for further research.

4. The Patents Full-Text Database and the Image Database allow you to retrieve patent documents that include the CPC classification. By focusing on the abstracts and representative drawings, you can narrow down your search for the most relevant patent publications.

5. This selection of patent publications is the best to look at for any similarities to your invention. Pay attention to the claims and specification. Refer to the applicant and patent examiner for additional patents.

6. You can retrieve published patent applications that match the CPC classification you chose in Step 3. You can also use the same search strategy that you used in Step 4 to narrow your search results to only the most relevant patent applications by reviewing the abstracts and representative drawings for each page. Next, examine all published patent applications carefully, paying special attention to the claims, and other drawings.

7. You can search for additional US patent publications by keyword searching in AppFT or PatFT databases, as well as classification searching of patents not from the United States per below. Also, you can use web search engines to search non-patent literature disclosures about inventions. Here are some examples:

• Add keywords to your search. Keyword searches may turn up documents that are not well-categorized or have missed classifications during Step 2. For example, US patent examiners often supplement their classification searches with keyword searches. Think about the use of technical engineering terminology rather than everyday words.
• Search for foreign patents using the CPC classification. Then, re-run the search using international patent office search engines such as Espacenet, the European Patent Office’s worldwide patent publication database of over 130 million patent publications. Other national databases include:
• European Patent Office (EPO) provides esp@cenet to access a network of Europe’s patent databases with access to machine translation of European patents. 
• Japan Patent Office (JPO) – with access to machine translations of Japanese patents.
• World Intellectual Property Organization (WIPO) offers PATENTSCOPE with a full-text search of published international patent applications and machine translations for some documents, as well as a list of international patent databases.
• Korean Intellectual Property Rights Information Service (KIPRIS)
• State Intellectual Property Office (SIPO) with machine translation of Chinese patents.
• Other International Intellectual Property Offices with online patent databases include Australia, Canada, Denmark, Finland, France, Germany, Great Britain, India, Israel, Netherlands, Norway, Sweden, Switzerland, and Taiwan.
• Search non-patent literature. Inventions can be made public in many non-patent publications. It is recommended that you search journals, books, websites, technical catalogs, conference proceedings, and other print and electronic publications.

To review your search, you can hire a registered patent attorney to assist. A preliminary search will help one better prepare to talk about their invention and other related inventions with a professional patent attorney. In addition, the attorney will not spend too much time or money on patenting basics.

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