Optical Device and Method

Abstract

According to one aspect of the present invention, there is provided an optical device manufactured in accordance with an extended reality optical design, the optical device comprising a plurality of optical elements for transmitting light from a light source for display on the user's eye, wherein the optical device includes a light source for generating light, a lens assembly configured to receive light off-axis from the light source, a first device at least partially coated with a mirror, a second optical device positioned intermediate the lens assembly and the first device at least partially coated with a mirror, the second optical device being configured to receive light from the lens assembly and transmit the light to the first device at least partially coated with a mirror, and a combiner for receiving light from the first device at least partially coated with a mirror and guiding the light to form a virtual image at an exit pupil located at the position of the eye.

Description

Technical Field

[0001] The present invention relates to optical devices and methods.

Background Art

[0002] Augmented reality optical devices are well known and are intended to provide real-world images and virtual images that are superimposed when presented to a user. Many augmented reality optical devices are, for example, intended to be worn by a user in a head-mounted device (HWD), a head-mounted display (HMD) or a helmet. In order to avoid causing physical discomfort to the user, it is useful if the device worn is lightweight and compact. This is not always the case.

[0003] Therefore, there is a need for an improved, compact and lightweight optical device for use in augmented reality optical designs.

Summary of the Invention

[0004] According to one aspect of the present invention, there is provided an optical device manufactured according to an augmented reality optical design, the optical device comprising a plurality of optical elements for transmitting light from a light source for display above a user's eye, wherein the optical device comprises a light source for generating light, a lens assembly configured to receive light off-axis from the light source, a first device at least partially coated with a mirror, and a second optical device located intermediate the lens assembly and the first device at least partially coated with a mirror, the second optical device being configured to receive light from the lens assembly and transmit the light to the first device at least partially coated with a mirror, and a combiner configured to receive light from the first device at least partially coated with a mirror and direct the light to form a virtual image at an exit pupil located at the position of the eye.

[0005] In one aspect, the second optical device may be arranged to be substantially orthogonal to the first at least partially mirrored device.

[0006] In one aspect, the second optical device is partially transmissive.

[0007] In one aspect, the second optical device is a second at least partially mirrored device.

[0008] In one aspect, the first at least partially mirrored device and the second optical device are tilted about their respective axes.

[0009] In one aspect, the first at least partially mirrored device and the second optical device together define an aperture for the light emitted by the light source.

[0010] In one aspect, the shape or size of the first at least partially mirrored device and the second optical device is correlated with the shape or size of the exit pupil.

[0011] In one aspect, the first at least partially mirrored device and the second optical device narrow the light.

[0012] In one aspect, the lens assembly is on axis with the first at least partially mirrored device.

[0013] In one aspect, the second optical device enables light to be directed to at least a partially reflective surface of the first at least partially mirrored device.

[0014] In one aspect, the light source is a light emitting source including a plurality of self-luminous pixels.

[0015] In one aspect, each pixel is adapted for illumination and emission over a wide cone angle greater than + / - 25 degrees.

[0016] In one aspect, the light source is a micro-LED display.

[0017] In one aspect, a light source that generates light, a lens assembly, a first device at least partially coated with a mirror, a second optical device, and a combiner are configured to fold the optical path around a first axis (XYZ) and a second axis (XYZ).

[0018] In one aspect, the first device at least partially coated with a mirror and the combiner are substantially parallel.

[0019] In one aspect, forming a portion of a wearable device, wherein at least a portion of the optical device is folded upward or to the side of the user's forehead.

[0020] In one aspect, at least a portion of the optical device comprises a light source, a lens assembly, and a second optical device.

[0021] In one aspect, the first device at least partially coated with a mirror comprises a mirror or a lens.

[0022] In one aspect, the second optical device is configured to change the brightness of the light.

[0023] In one aspect, the second optical device has a reflectivity or transmissivity that is electronically controllable.

[0024] In one aspect, the virtual image is combined with the real-world image by the combiner.

[0025] According to one aspect of the present invention, there is provided a binocular optical device comprising two optical devices according to another aspect.

[0026] According to one aspect of the present invention, there is provided a wearable device including one or two optical devices according to another aspect.

[0027] According to one aspect of the present invention, there is provided a system comprising a plurality of processors configured to transmit and receive data and process the data, one or more sensors configured to collect at least a part of the data from the environment and send the data to the processors, and one or more wearable devices according to another aspect.

[0028] According to one aspect of the present invention, there is provided a method of guiding light through an optical device fabricated according to an extended reality optical design, the optical device comprising a plurality of optical elements for transmitting light from a light source for display over a user's eye, emitting light via the light source, reflecting, via a second optical device, a part of the light received from a lens assembly towards a first device at least partially coated with a mirror, guiding light, via the first device at least partially coated with a mirror, towards a combiner, and guiding light, via the combiner, to form a virtual image at an exit pupil of the optical device.

[0029] In one aspect, reflecting, via a second optical device, a part of the light received from a lens assembly towards a first device at least partially coated with a mirror comprises using a second device at least partially coated with a mirror.

[0030] In one aspect, arranging the first device at least partially coated with a mirror and the second optical device substantially orthogonally and tilting the first device at least partially coated with a mirror and the second optical device about their respective axes.

[0031] Next, embodiments of the present invention will be described merely by way of example with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032]

Figure 1

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Figure 4

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Figure 10

DETAILED DESCRIPTION OF THE INVENTION

[0033] The present invention relates to an augmented reality optical design for providing real-world images and virtual images that are superimposed when presented to a user. The augmented reality optical design is also referred to as an optical device designed according to the augmented reality optical design. The optical device is a part of an optical system that is used in many different contexts to provide information to a user. In some cases, this is for displaying information to a pilot of a vehicle such as an aircraft.

[0034] Generally, such systems are designed to utilize a light-emitting display. The light-emitting display generally has a wide cone angle of emission. This can present a problem if the total amount of light emitted by the display is not precisely controlled. FIG. 1 shows an ideal emission 100 and two non-ideal emissions 102 and 103. Light emitted by the display source outside the cone angle required by the optical system to meet the exit pupil requirements passes through the system and can degrade one or more display parameters (e.g., contrast) or proceed towards the eye. If this light is then visible to the user, it can create an area of the exit pupil where the display is not adequately corrected (e.g., blurry) but still visible (scenario 102). Scenario 103 shows how a physical aperture 104 can be used to limit visible light, as will be described in more detail below with respect to the present invention. Note that the aperture 104 can alternatively be present inside the optical system (i.e., not in front of the eye), such as a light shield in a conventional optical projection system.

[0035] FIG. 2 is a schematic view of a folded linear structure. A known linear system is modified so that the eye 200 can view an image through the use of a combined mirror 204. An aperture position 206 inside the lens system 208 is required to prevent the eye from viewing uncorrected light 210. This results in a real emission viewed through the mirror, controlled by the internal aperture position 206.

[0036] Conventionally, the apertures would be absorption plates with cutouts. These are not suitable as they limit the flexibility of the layout and require additional mechanical components or more complex housing designs.

[0037] In the present invention, as shown in FIG. 3, the apertures are defined in a different manner, overcoming the problems of traditional apertures in augmented reality optical designs.

[0038] As shown in Figure 3, the present invention includes an aperture which is the aperture of the mirror base 300. Only the light rays hitting the mirror 300 are on the correct optical path to travel towards the eye 200. Therefore, the shape and / or size of the mirror 300 has a direct correlation with the shape and / or size of the exit pupil generated by the system, and thus the light traveling towards the exit pupil can be restricted thereby. The system further includes a single lens (for simplicity), but may include more complex configurations. The light rays passing through the system by using the aperture of the mirror base can be narrowed, but the system is simultaneously folded, providing increased flexibility, space savings and other related improvements. The light restricted by the mirror can optionally be filtered (dotted line) 310 to enable additional control over the bandwidth of the optical light propagating through the system.

[0039] The mirror 300 is located on or near the light shield of the system, and thus the light beam over the total field of view of the system is incident over a clearly defined, small area. The mirror 300 is configured to be used to perform additional optical functions such as filtering or dimming of the incident light by variations in its design. This may involve the use of different optical coatings, materials, etc. Similar functions may be achieved by placing a conventional filter on a conventional transmissive optical aperture plate, but this also increases the number of components, which is undesirable. Furthermore, a conventional filter needs to absorb or reflect the filtered light, which presents the risk that it is reflected or scattered back into the lens configuration. However, in the mirror configuration of Figure 3, the light not reflected by the mirror passes through to the rear surface of the mirror and is absorbed. There is no stray illumination and spurious light is avoided.

[0040] A further benefit of the addition of the partially transmissive mirror is that a portion of the light from the lens configuration transmitted by the mirror may be collected by an auxiliary small lens system configured behind the mirror, such as a camera lens system, and a sensor configured to monitor the display content for monitoring. A further benefit is that additional light can be injected into the optical system from behind the mirror, such as IR illumination for eye tracking purposes or an additional / secondary display lens configuration to provide additional optical functionality.

[0041] The basic concepts described above are further developed and provide further benefits as will be described with reference to FIGS. 4 and 5. As previously mentioned, the light emitting image source (e.g., optical device) according to the present invention has a wide cone angle of light emission. The light emitting image source 424 includes a plurality of self-luminous pixels. Each pixel is capable of irradiating and emitting light over a wide cone angle. The cone angle is greater than about + / -25 degrees and up to about + / -90 degrees. However, as will be described in more detail below, the optical device of the present invention compensates for the problem of stray light in an optical device that would normally cause degradation of display content such as lower contrast or secondary images. In the present application, the image source, also referred to as the light source, generates light that passes through the optical device and forms an image as soon as it reaches the user's pupil. Further, the light source can be changed for different situations to cover visible and non-visible wavelengths.

[0042] In the first scenario of FIG. 4, light is directed by the optical device 402 towards the eye 400. The optical device 402 includes a relay lens or lens assembly 404, a first element 406, and a combiner element 408. The approximate position of the second element is shown as 410. In FIG. 5, the second element 412 is shown. The first and second elements 406 and 412 are, in one example, mirrors. In the figure, the X-axis crosses the eye, the Y-axis points outward from the head, and the Z-axis points from the top to the bottom of the head.

[0043] In FIG. 4, the device is deployed about the position 410 of the second mirror, and second, with the second mirror 412 inserted, the device is further folded in-plane with respect to the figure. The second mirror 412 is rotated about the Y axis, which is not shown in the sketch for clarity as the sketch is a 2D projection. The mirror can be rotated about the X or Y axis, adding flexibility to the folding configuration, for example, it may fold the system upward or to the side of the forehead. It is optimal to place the second mirror 412 near or ideally around the shield of the device. The device includes appropriate apertures, and at the same time, it folds the relay lens at an angle such that it wraps around the perimeter of a typically shaped head (as shown in FIGS. 8 and 9). In some cases, the second mirror is an optical device that is partially transmissive to filter out unwanted light or transfer it to an absorption region. The optical device enables light to be directed to at least a partially reflective surface of the first mirror device. The figure shows a single ray from the theoretical exit pupil position for three nominal sets of field angles. It will be appreciated that a wider exit pupil area will provide multiple field angles (i.e., the coverage of the lens and / or mirror with rays will be wider than shown).

[0044] The optical device is configured such that there are two folding optical paths defined. The first one is at the second mirror and the second one is at the first mirror. This configuration ensures a compact device as also shown in FIG. 7. As a result of the two foldings, the overall optical device includes a portion configured to be supported at the side of the head during use. This enhances the comfort and weight of the device as the housing for the device is smaller and lighter, making it more practical to wear the optical device. Further, the field of view through the combiner is not interfered with by a bulky or visible device. This can be achieved by angling the combiner, i.e., tilting it with respect to the horizontal axis. Such an angled eyepiece can allow space for the user to wear personal eyewear such as vision correction glasses when sufficiently separated from the user's face. This embodiment provides a buffer (i.e., stand-off distance from the eye to the combiner) of 53.5 mm between the combiner and the eye. However, a range of 48 to 59 mm is contemplated for alternative embodiments.

[0045] The combiner defines a plane generally parallel to the plane defined by the first mirror. The axis defined by these planes is generally parallel to the Y axis. Such a provision further aids in using a compact form and can free up space in the area corresponding to the user's nasal bridge.

[0046] The combiner element 408 has an aspherical surface form tilted about at least a first axis, in this case the X-axis. The surface form is also decentered about the Y-axis, i.e., the central ray in the FOV does not hit the center of the optical surface form. The combiner is configured to change the direction of one or more wavelengths towards the user to enable the user to view a virtual display created by an optical device simultaneously with the outside world 414. The combiner 408 is configured to change the direction of light incidence therethrough by use of an optical coating applied over at least a portion of the surface of the combiner. The coating is preferably applied over the entire surface, or alternatively, only over the "optically active" region of the combiner, e.g., only where the rays may hit the combiner and not other places. The aspherical shape is used to help compensate for off-axis aberrations. Since the combiner is tilted, it induces optical aberrations in the light of the image.

[0047] In particular, since the combiner is off-axis with respect to the linear path of the light, aberrations occur, and these aberrations can include spherical aberration, coma aberration, astigmatism aberration, and distortion aberration. The combiner is tilted to accurately change the direction of the light, and if it is not tilted accurately, the light will not be sent towards the eye. Using only a spherical surface form limits the degree of freedom of optical correction in the design, allowing the combiner to have a more complex surface form, e.g., a bi-conic surface, and thus providing additional degrees of freedom for better correcting the aberrations caused by the fact that the element is tilted.

[0048] The use of a bi-conic surface form has several advantages. Different radii on both the X-axis and the Y-axis enable different refractive powers on both axes and also enable the introduction of a conical contribution to both the X-axis and the Y-axis. The conical contribution changes the spherical form to an alternative surface form shape such as an ellipsoidal surface, a hyperbolic surface, or a parabolic surface depending on the value of the conical contribution, and they are more eccentric with respect to the shape and help compress the light beam of the reflected light into a smaller bundle compared to a typical spherical surface form.

[0049] The combiner includes a first optical surface form on its inner surface 416 and a different second optical surface form on its outer surface 418 to minimize deviation to the external field of view 414. The surface form on the outer surface 418 is described by a different set of optical parameters relative to the inner surface 416. The outer surface 418 is generally not coaxial with the inner surface 416, and the thickness between the two surfaces varies across the area of the combiner 408. The surface forms are generally described by different radii and conic constants of the X and Y axes such that they are both bi-cones with different optical prescriptions. In some cases, the surface forms may have additional complexity as described by a higher order polynomial function or through the inclusion of aspherical form contributions.

[0050] In addition to the optical coating, the combiner 408 is generally configured to change the direction of light through the use of one of an optical element of a holographic optical element, diffractive optical element, or optical microstructure (none shown) applied across the area of the combiner. The use of these optical techniques can provide additional degrees of freedom to change or orient the direction of the light beam of light in the system in a manner that cannot be achieved with the use of a reflective coating alone. As an example, a holographic or diffractive optical element may be able to change the direction of light at more extreme angles according to the laws of diffraction without the need to induce additional tilt to the combiner element as would be required if only reflective optical coatings whose design is limited by the laws of reflection were used.

[0051] In some cases, the combiner 408 is made of a plastic material and includes coatings with various functions as described above. The result is an efficient and highly transmissive component that is well-suited for use in an extended reality optical design. In most cases, the combiner has a transmittance suitable for viewing the extended reality field of view of the symbology and the external world. If the optical device is to be used in a virtual environment, the transmittance of the combiner can be reduced almost to zero.

[0052] The first mirror 406 is optically powered, and its front surface 420 can be decentered and tilted. Different combinations of power, tilt, and decentering are used depending on the required layout and / or configuration of the device. The first mirror 406 reflects to one side or the other. In a first case, the first mirror comprises a reflective first surface from which light receives a first surface reflection. In a different case, the first mirror includes a transmissive first surface and a reflective second surface, where light passes through the mirror, receives a second surface reflection, and passes back through the first surface, in which case the element acts like a conventional lens with a reflective back surface, adding additional degrees of freedom to the design.

[0053] The first mirror 406 is located near the intermediate image plane of the optical design and serves to help define or limit the field of view of the image presented to the user by its size and shape. When light is not reflected by the mirror, it does not continue to travel towards the combiner and the user's eye; instead, it is absorbed by the surrounding chassis or support, thereby improving stray light control. The first mirror 406 limits the visible field of view presented to the user by acting as an optical aperture. The first mirror 406 also enables the optical design to fold the optical path around the user's head and be tiltable or rotatable about two or more axes. Configuring the first mirror to be tiltable can also help compensate for aberrations induced by the tilted combiner.

[0054] The second mirror 412 is tilted with respect to the axis of the first mirror by at least a second axis and includes at least one partially reflective surface on its inner or outer surface. The second mirror 412 is configured at or near the aperture location of the system, which is between the relay lens and the first mirror, and is shaped such that it also acts as an optical aperture to limit the light that travels into the exit pupil presented to the user.

[0055] The partially reflective surface of the second mirror is partially transmissive at one or more wavelengths. Thus, the light passing through the optical device is filtered by reflecting only some optical wavelengths to limit which wavelengths are directed towards the optical combiner, which can be beneficial since the optical coating applied to the combiner can be optimized to be over an individual set of wavelengths as opposed to the complete set of wavelengths emitted by the display or image source. This can help reduce the impact that the optical coating has on the user's view of the real world, for example, by maximizing the transmittance across the visible spectrum of wavelengths.

[0056] The second mirror may also be enhanced to enable additional features such as the ability to change the brightness of the virtual content. As an example, the mirror may have a reflectivity or transmittance that is electronically controllable, and thus, the user may control the brightness of the system by electronically controlling the reflectivity or transmittance of the surface to allow more or less light to pass through the device. Alternatively, an electronically controllable filter, such as a liquid crystal device, may be configured over the mirror to provide variable absorption of the incident light, and thus, the user may control the brightness of the system by electronically controlling the absorption of the element to allow more or less light to pass through the device.

[0057] To reduce any stray light, an optical absorption region is configured behind the second mirror such that any transmitted light is preferably absorbed and cannot return to the optical device.

[0058] As can be seen from FIG. 5, by substantially orthogonally aligning the axes of each mirror, the optical path includes double refraction in at least two dimensions or axes. This means that the overall size of the optical device is reduced, further resulting in improvements in the number, weight, and efficiency of the components without any compromise to the optical quality.

[0059] Although not shown in FIGS. 4 and 5, the optical device 402 is part of an optical system that includes additional features and functions. The optical system further includes an image source that generates light that is ultimately delivered to the user in the form of a virtual image. The image source comprises at least one self-luminous display (not shown) capable of activating a plurality of light-emitting single pixel sources that emit visible light at one or more wavelengths to form a digital display. The light from the image source extends over a given area and cone angle. This light is referred to as large cone emission and comes from a display referred to as a large cone emission device or display. Generally, the angle of the cone of emission may be any of up to approximately + / -90 degrees, or a much smaller cone angle, e.g., approximately + / -25 degrees, in order to satisfy the exit pupil of the designed system. This is why it is important to accurately control the unwanted cone angles, as otherwise there is a possibility of the optical system propagating to the eye.

[0060] The image source is a self-luminous display, a micro LED array, a plurality of display panels or any other suitable source.

[0061] The image source is tilted with respect to the relay lens by at least one axis. In some cases, the image source is a micro LED display panel. The image created through the optical system is combined with the real-world image from the combiner to provide an extended image. In other cases, multiple image sources may be used and combined using optical filters, e.g., individual red, green, and blue display panels may be used instead of a single display panel capable of emitting red, green, and blue light and combined using a set of dichroic filters.

[0062] In some cases, the optical device will instead be wearable. In these cases, the optical device is stored in a housing connected to a helmet or other wearable frame, or forms an integral part of the helmet or frame. The optical devices in these instances include head-mounted devices (HWDs), head-mounted displays (HMDs), or any other suitable device.

[0063] The content of the augmented image includes symbology related to the interface where the optical device or system is used. The symbology can include at least one or more of signs and symbols, data from sensors, processed data from sensors, combinations of sensor data, military symbology, vehicle-related symbology, scene-related symbology, location and positioning symbology, map symbology, speed and velocity symbology, etc. Additionally, full-frame video can be displayed in addition to the symbology.

[0064] The optical device forms part of a system (not shown), which in some cases is used to control and / or navigate a vehicle in an environment. The system generates symbology and other information that needs to be displayed to the user. The system includes sensors for collecting data from the vehicle-related environment, and a processor for receiving, transmitting, and processing data to determine the data that will be displayed to the user by the optical device according to the present invention. The user can be an aircraft pilot, and the system can be an aircraft system.

[0065] The optical device includes relay lenses 404, 600, which will be described in more detail next with reference to FIG. 6 showing several different configurations of lenses 602, 604, and 606. These are three of many possible configurations. The lenses are made of any suitable material. For weight reduction, the lenses are made of plastic material or glass in at least some cases. The relay lenses provide further improvement to the augmented reality optical design and are shown as part of this optical device, but can be used in many other situations where a high-quality, lightweight lens solution is required.

[0066] Relay lens 600 is designed to be as simple as possible while maintaining the required level of performance to minimize cost and the number of components. Relay lens 600 for each configuration 602, 604, and 606 includes three lenses: two singlets 608, 610 and one doublet 612. At least one or more lenses have a planar (flat) rear surface, in this case, singlet 610. It should be further noted that lenses 608 and 612 are configured as optical doublets combined to provide a certain level of color correction.

[0067] In particular, therefore, a relay lens 600 is provided that includes a series of coaxial lens elements.

[0068] Due to its proximity to the image source, the first lens element in the series is a plano-convex lens 610 configured with its flat rear side facing the image source.

[0069] The second lens element in the series is a bi-concave and bi-convex doublet lens 612 with both concave portions facing the convex side of the first lens element.

[0070] The third lens element in the series is a bi-convex lens 608.

[0071] Such a relay lens configuration, in conjunction with the surrounding optical architecture described herein, can eliminate the need for additional lens elements elsewhere in the optical path.

[0072] As shown in configuration 602, all the lenses are coaxially aligned for simplicity and ease of assembly, but they are configured away from the optical axis of the optical device. This configuration is achieved through performance optimization, and the lenses are decentered and tilted with respect to the off-axis optical path to correct for off-axis aberrations induced by the off-axis combiner. Further, in particular, the image plane is also tilted with respect to the lens assembly to achieve the best focus. Configuration 604 is the same as 602 and shows the central ray across the total field of view.

[0073] The improvement of configurations 602 and 604 is that it is recognized that a portion of the lens is unused during design, and thus the relay lens is cut so that only the portion of the lens that supports the optical path is retained. During the design of multiple lenses, the trajectory of the expected light beam that will pass through the lenses is identified. Material can be removed from each lens of the multiple lenses through which the expected light beam is not predicted to pass. The modification to the lenses in the relay lens is used to update the augmented reality optical design.

[0074] Lens configuration 606 is beneficial for mass / volume reduction, but it also makes the lens act as an additional individual aperture, and light that might normally pass through the upper part of the lens cannot do so. This avoids additional stray light in the optical device. A further measure is to ensure that the relay lens element has a suitable absorption end, for example, through the use of black paint. Note that the optical prescription of each lens in the configuration can be configured as needed to suit the required function.

[0075] The optical device can operate as a monocular device, but the most likely use is as a binocular configuration as shown in FIG. 7 having two optical devices 402. Each optical device includes an imaging optical element for the user's right or left eye. Thus, all components are designed to be detachable for simplicity, and the number of individual parts can be reduced. The optical paths for either eye do not cross, and the optical paths for either eye are completely separate. This improves configurability, maintenance options, and minimizes the risk of crosstalk or stray light between the two eyes. The displays are also completely independent, so that if one optical channel fails or is damaged, the user still has the remaining display available to the other eye, and completely separate content can be provided to either eye, for example, providing stereoscopic content.

[0076] The binocular configuration is supported by a frame, housing, or helmet designed to be worn by the user. As can be seen in FIG. 7, the field of view is a top-down view with only the axial light beam shown for clarity. As shown, the mirrors are configured to conveniently fold the optical elements around the arc of the head (e.g., around the forehead) so that they are directed upward away from the user's line of sight and do not significantly affect the user's peripheral vision.

[0077] Optical device / Each optical device is housed in a housing (not shown). The housing of the head-mounted device must be as lightweight as possible to avoid burden on the user's neck and other discomfort. The housing must not only be compact, but also contain the optical device without any optical element occupying any of the user's FOV. If an optical element becomes "obstructive", this can cause accidents and unclear vision for the user. The present invention provides solutions to these problems. As can be seen in FIG. 7, the optical elements 404, 406, 408 and 412 allow a dual configuration of the elements such that the lens assembly is outside the field of view and located around the head. Thus, the optical device is small, compact and lightweight without any compromise in optical quality and performance.

[0078] FIGS. 8 and 9 show simple mock-ups of the final optical design. From these figures, it can be seen that light is emitted from an image source such as the light-emitting display described above and collected by a relay lens. The relay lens focuses the light towards a second mirror located near the light shield of the optical design. The mirror reflects the light towards a first mirror, which also has a refractive power and the light is then reflected towards the combiner element. The combiner is configured to be partially see-through and thus partially reflects and returns the light of the display towards the user while combining the view from the outside world.

[0079] Next, the way the optical device moves will be described with reference to the flowchart of FIG. 10.

[0080] The operation method 1000 of the augmented reality optical design is as follows.

[0081] In step 1002, light is emitted by an image source 424 over a given area and cone angle, and a portion is received by a relay lens assembly 404.

[0082] In step 1004, the relay lens assembly 404 directs light towards an intermediate aperture within the system. Any light not transmitted by the relay lens assembly 404 is mostly absorbed within the assembly, thus controlling stray light emitted by the image source.

[0083] In step 1006, the second mirror 412 reflects a portion of the incident light received from the relay lens assembly 404 towards the first mirror 406. Any light outside the aperture of the second mirror 412 is not reflected, thus helping to shape the exit pupil of the optical device 402.

[0084] In step 1008, the first mirror 406 receives the light and directs it towards the combiner 408. Any light outside the aperture of the first mirror 406 is not redirected, thus helping to shape the field of view of the optical device 402.

[0085] In step 1010, the combiner 408 receives the light from the first mirror 406 and partially redirects it towards the user, forming an exit pupil at the location of the eye 400. Thus, the user is able to view a virtual display that is focused between approximately 30 cm and infinity, depending on the configuration of the relay lens assembly 404 and the positioning of the image source.

[0086] In step 1012, light is directed towards the eye 400 through the exit pupil of the optical device 402, which is partially defined by the shape of the relay lens assembly 404 and the second mirror 212. Thus, the risk of viewing stray or uncorrected portions of the image is minimized if the user moves their eye 400 outside the defined / corrected exit pupil.

[0087] The exit pupil or eyebox is the region in space where the image appears clear and in focus because it is optically well corrected. As the eye moves around in this space, the clarity of the virtual image can vary and, in particular, can become worse as the eye moves towards the edge of the defined exit pupil or outside the defined exit pupil. In general, an optical display system is designed to correct the image only across the exit pupil, as defined by the optimization software. Instead, the present invention uses a number of apertures to ensure that the exit pupil cannot become larger than designed due to additional light emission from the image source (i.e., a larger angle in the cone of emission).

[0088] There are many variations and aspects that may be included within the claims, and thus it should be understood that these alternatives are intended to be covered by the claims.

[0089] According to one example, an optical device manufactured according to an extended reality optical design, the optical device comprising a plurality of optical elements for transmitting light from a light source for display over a user's eye, wherein the optical device comprises a light source for generating light, a lens assembly configured to receive light off-axis from the light source, a first device at least partially coated with a mirror, a second optical device disposed substantially orthogonally to the first device at least partially coated with a mirror and located intermediate the lens assembly and the first device at least partially coated with a mirror, the second optical device configured to receive light from the lens assembly and transmit light to the first device at least partially coated with a mirror, and a combiner configured to receive light from the first device at least partially coated with a mirror and direct the light to form a virtual image at an exit pupil located at the position of the eye.

Claims

1. An optical device manufactured according to an augmented reality optical design, the optical device comprising a plurality of optical elements for transmitting light from a light source for display over a user's eye, wherein the optical device is a light source for generating the light, a lens assembly configured to receive the light, off-axis from the light source, a first device at least partially coated with a mirror, a second optical device positioned intermediate the lens assembly and the first device at least partially coated with a mirror, the second optical device configured to receive the light from the lens assembly and transmit the light to the first device at least partially coated with a mirror, a combiner that receives the light from the first device at least partially coated with a mirror and directs the light to form a virtual image at an exit pupil located at the position of the eye and an optical device.

2. The optical device according to claim 1, wherein the second optical device is partially transmissive.

3. The optical device according to claim 1 or claim 2, wherein the second optical device is a second device at least partially coated with a mirror.

4. The optical device according to any one of claims 1 to 3, wherein the first device at least partially coated with a mirror and the second optical device are tilted about their respective axes.

5. The optical device according to any one of claims 1 to 4, wherein the first device at least partially coated with a mirror and the second optical device in combination define an aperture for the light emitted by the light source.

6. The optical device according to any one of claims 1 to 5, wherein the shape or size of the first device at least partially coated with a mirror and the second optical device is correlated with the shape or size of the exit pupil.

7. The optical device according to any one of claims 1 to 6, wherein the first device at least partially coated with a mirror and the second optical device narrow the light.

8. The optical device according to any one of claims 1 to 7, wherein the lens assembly is on the axis with the first device at least partially coated with a mirror.

9. The second optical device according to any one of claims 1 to 8, which is capable of guiding the light to at least a partially reflective surface of the first device with at least a partial mirror.

10. The optical device according to any one of claims 1 to 9, wherein the light source is a light emitting source including a plurality of self-luminous pixels.

11. The optical device according to claim 10, wherein each pixel is adapted for irradiation and light emission over a wide cone angle greater than + / −25 degrees.

12. The optical device according to claim 10 or claim 11, wherein the light source is a micro LED display.

13. The light source for generating the light, the lens assembly, the first device with at least a partial mirror, the second optical device, and the combiner are configured to fold the optical path around a first axis (XYZ) and a second axis (XYZ). The optical device according to any one of claims 1 to 12.

14. The optical device according to any one of claims 1 to 13, which forms a part of a wearable device, and at least a part of the optical device is folded upward or to the side of the user's forehead.

15. The optical device according to claim 14, wherein the at least a part of the optical device includes the light source, the lens assembly, and the second optical device.

16. The optical device according to any one of claims 1 to 15, wherein the first device with at least a partial mirror includes a mirror or a lens.

17. The optical device according to any one of claims 1 to 16, wherein the second optical device is configured to change the brightness of the light.

18. The optical device according to claim 17, wherein the second optical device has a reflectivity or transmissivity that is electronically controllable.

19. The optical device according to any one of claims 1 to 18, wherein the virtual image is combined with a real-world image by the combiner.

20. The optical device according to any one of claims 1 to 19, wherein the first device with at least a partial mirror and the combiner are substantially parallel.

21. A binocular optical device comprising two optical devices according to any one of claims 1 to 20.

22. A wearable device comprising one or two optical devices according to any one of claims 1 to 21.

23. A system comprising: a plurality of processors configured to transmit and receive data and process the data; one or more sensors configured to collect at least a portion of the data from the environment and send the data to the processors; one or more wearable devices according to claim 22; and a system.

24. A method of guiding light through an optical device fabricated according to an extended reality optical design, the optical device comprising a plurality of optical elements for transmitting light from a light source for display over a user's eye, emitting light via a light source; reflecting, via a second optical device, a portion of the light received from a lens assembly toward a first device at least partially coated with a mirror; guiding the light toward a combiner via the first device at least partially coated with a mirror; and guiding the light via the combiner to form a virtual image at an exit pupil of the optical device. and a method.

25. Reflecting, via a second optical device, a portion of the light received from a lens assembly toward a first device at least partially coated with a mirror comprises using a second device at least partially coated with a mirror, the method according to claim 24.

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