Optical Device and Method

Abstract

An optical device made according to an augmented reality optical design, the optical device comprising a plurality of optical elements for transmitting light from a light source to be displayed above a user's eye, the optical device comprising a light source that generates light, a lens assembly that is off-axis from the light source and is configured to receive the light, wherein the lens assembly includes a plurality of lenses, wherein the lens assembly has a tip cut off by removing material from one or each of a plurality of lenses that are predicted not to be traversed by a predicted light beam, and a combiner that receives light from the lens assembly via one or more additional optical elements of the plurality of optical elements and sends the light to form a virtual image at an exit pupil 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 intended to be worn by a user, for example, in a head-worn device (HWD), a head-mounted display (HMD), or a helmet. To avoid causing physical discomfort to the user, it is useful for the device to be worn to be lightweight and small. This is not always the case.

[0003] Therefore, there is a need for an improved small 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 made according to an augmented reality optical design, the optical device comprising a plurality of optical elements for transmitting light from a light source onto a user's eye, the optical device comprising a light source for generating light, a lens assembly having an off-axis axis from the light source and configured to receive light, wherein the lens assembly includes a plurality of lenses, wherein the lens assembly has a tip cut off by removing material from one or each of a plurality of lenses through which it is predicted that the expected light beam will not pass, and a combiner for receiving light from the lens assembly via one or more additional optical elements of the plurality of optical elements and sending the light to form a virtual image at an exit pupil at the position of the eye.

[0005] In one aspect, the lens assembly is a relay lens.

[0006] In one aspect, the lens assembly comprises three or more lenses.

[0007] In one aspect, the lens assembly is made of a plastic material or glass.

[0008] In one aspect, the lens assembly comprises a combination of a singlet lens and a doublet lens.

[0009] In one aspect, at least one of the plurality of lenses has a back surface without a degree.

[0010] In one aspect, at least two of the plurality of lenses are arranged as a joined optical doublet.

[0011] In one aspect, the plurality of lenses are arranged coaxially.

[0012] In one aspect, each of the plurality of lenses includes an absorption edge.

[0013] In one aspect, each of the plurality of lenses has a different optical prescription.

[0014] In one aspect, each of the plurality of lenses includes an absorption edge.

[0015] In one aspect, one or more additional optical elements among the plurality of optical elements include a first device provided with at least a partially mirror, and a second optical device positioned substantially orthogonally to the first device provided with at least a partially mirror and located intermediate the lens assembly and the first device provided with at least a partially mirror, the second optical device being configured to receive light from the lens assembly and transmit the light to the first device provided with at least a partially mirror.

[0016] In one aspect, the light source is a light emitting source including a plurality of self-luminous pixels.

[0017] In one aspect, each pixel is adapted for illumination and emission over a wide cone angle greater than ±25°.

[0018] In one aspect, the optical device is configured to fold the optical path around a first axis (XYZ) and a second axis (XYZ).

[0019] In one aspect, the optical device forms part of a wearable device, and at least a portion of the optical device is folded above or to the side of the user's eyebrow.

[0020] According to one aspect of the present invention, an optical device made according to an extended reality optical design, the optical device comprising a plurality of optical elements for transmitting light from a light source onto the user's eye, the optical device comprising a light source for generating light, a lens assembly having an off-axis axis and configured to receive light, wherein the lens assembly includes a plurality of lenses, and wherein the lens assembly has a tip cut off by removing material from one lens or each lens among a plurality of lenses through which it is predicted that the expected light beam will not pass, receiving light from the lens assembly through one or more additional optical elements of the plurality of optical elements, and a combiner for sending the light to form a virtual image at an exit pupil at the position of the eye, wherein the combiner has a first inner optical surface shape and a second outer optical surface shape, wherein the first inner optical surface shape is different from the second inner optical surface, minimizing the deviation in the outer field of view from the combiner, and wherein one or more additional optical elements of the plurality of optical elements include a first device provided with at least a partially mirror, and a second optical device positioned substantially orthogonally to the first device provided with at least a partially mirror and located intermediate the lens assembly and the first device provided with at least a partially mirror, the second optical device being configured to receive light from the lens assembly and transmit the light to the first device provided with at least a partially mirror, an optical device is provided.

[0021] According to one aspect of the present invention, there is provided a binocular optical device comprising two optical devices according to another aspect.

[0022] According to one aspect of the present invention, there is provided a wearable device including one or two optical devices according to another aspect.

[0023] According to one aspect of the present invention, there is provided a system including 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 transmit the data to the processors, and a wearable device according to another aspect.

[0024] According to one aspect of the present invention, there is provided a method of sending light through an optical device made according to an extended reality optical design, the optical device including a plurality of optical elements for transmitting light from a light source onto a user's eye, the method including emitting light through a light source to a lens assembly, where the lens assembly includes a plurality of lenses, where the lens assembly has a tip cut off by removing material from one or each of a plurality of lenses where it is predicted that an expected light beam will not pass through, sending the light through one or more additional optical devices toward a combiner, and sending the light through the combiner to form a virtual image at an exit pupil of the optical device, where the combiner includes a first inner optical surface shape and a second outer optical surface shape, where the first inner optical surface shape is different from the second inner optical surface, and minimizing a shift in an outer field of view from the combiner.

[0025] In one aspect, the method further includes designing the optical device, determining an optical path through the design, identifying regions of the lens assembly where light is predicted not to pass through, and updating the design to cut off one or more tips of a plurality of lenses based on where the light is predicted to pass through.

[0026] In one aspect, in the lens assembly, lens material is removed from an area projected so that light does not pass through it.

[0027] In one aspect, an absorption edge is applied to each of a plurality of lenses.

[0028] In one aspect, one or more of a plurality of lenses are joined to each other.

[0029] Next, embodiments of the present invention will be described merely by way of example with reference to the drawings.

Brief Description of the Drawings

[0030]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Modes for Carrying Out the Invention

[0031] The present invention relates to an augmented reality optical design for providing real-world and virtual images that can be 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 part of an optical system that is used in a number of different contexts to provide information to a user. In some cases, this is to display information to a pilot of a vehicle such as an aircraft.

[0032] 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 pose a problem in that the total amount of light emitted by the display is not accurately 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 travels through the system and can reduce one or more display parameters (e.g., contrast) or can travel towards the eye. If this light is then visible to the user, in a region of the exit pupil, the display correction may be insufficient (e.g., blurred) 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., in front of the eye) like an optical stop in a conventional optical projection system.

[0033] FIG. 2 is a schematic diagram of a folded linear structure. A known linear system is modified so that the eye 200 can view an image by using a combined mirror 204. The aperture position 206 inside the lens system 208 is the position necessary to prevent the eye from viewing uncorrected light 210. Thereby, the actual emission is viewed through a mirror controlled by the internal aperture position 206.

[0034] Conventionally, the aperture is an absorption plate with a notch. These are not preferred as they limit the flexibility of the layout and require either additional mechanical components or a more complex housing design.

[0035] In the present invention, as shown in FIG. 3, the aperture is defined differently and solves the problems of conventional apertures in augmented reality optical designs.

[0036] As shown in FIG. 3, the present invention includes an aperture that is a mirror-based aperture 300. Only the light rays that hit the mirror 300 are on the correct optical path leading towards the eye 200. Thus, 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 (for simplicity) a single lens, but can include more complex configurations. By using the mirror-based aperture, the light rays passing through the system can be restricted simultaneously as the system is folded, improving flexibility, saving space, and obtaining other related improvements. The light restricted by the mirror can optionally be filtered (dotted line) 310, allowing additional control over the bandwidth of the light propagating through the system.

[0037] Mirror 300 is located at or near the optical aperture of the system. Thus, the light beam traversing the full field of view near the system is incident over a small, well-defined area. Mirror 300 is configured to be used to perform additional optical functions such as filtering or dimming of the incident light by deforming its design. In this case, it may be necessary to use different optical coatings, materials, etc. Similar functions can be achieved by placing a conventional filter on a conventional transmissive optical aperture plate, but in this case too, the number of components increases, which is not desirable. In addition, a conventional filter is required to either absorb or reflect the filtered light, and absorption or reflection of the light may cause the light to be reflected or scattered back into the lens configuration. However, in the mirror configuration of FIG. 3, the light not reflected by the mirror passes through to the back surface of the mirror and is absorbed. There is no stray light, and spurious light is avoided.

[0038] A further benefit of the partially transmissive mirror is that a portion of the light from the lens configuration transmitted by the mirror can be collected by an auxiliary small lens system placed behind the mirror, such as a camera lens system and sensor arranged to monitor the display count for monitoring purposes. A further advantage is that additional light can be injected into the optical system from behind the mirror, such as IR illumination for eye tracking or an additional / secondary display lens configuration to provide additional optical functions.

[0039] The basic concepts described above are further developed and provide additional benefits as described with reference to FIGS. 4 and 5. As previously mentioned, the emission image source (e.g., an optical device) according to the present invention has a wide cone angle of emission. The emission image source 424 includes a plurality of self-luminous pixels. Each pixel can illuminate and emit light over a wide cone angle. The cone angle is greater than about ±25° and up to about ±90°. However, as will be described in more detail below, the optical device of the present invention typically compensates for the problem of stray light within the optical device that causes degradation of the display content, such as a reduction in contrast or a secondary image. 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 when it reaches the user's pupil. Additionally, the light source can be modified to cover optical and non-optical wavelengths in different situations.

[0040] In the first case in FIG. 4, light is sent towards the eye 400 by the optical device 402. 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 element 406 and the second element 412 are, in one example, mirrors. In the figure, the X-axis crosses the eye, the Y-axis is outward from the head, and the Z-axis is in the direction from above the head downwards.

[0041] In FIG. 4, the device is deployed around the position 410 of the second mirror, and second, when the second mirror 412 is inserted, the device is further folded in the same plane as the drawing. The second mirror 412 is rotated about the Y axis, but this is not shown because the figure is a 2D projection for clarity. The mirror can be rotated about the X or Y axis, thereby improving the flexibility of the folding configuration, for example, the system can be folded upward or to the side of the eyebrow. It is optimal to position the second mirror 412 near or, ideally, around the aperture of the device. The device includes an appropriate aperture while folding the relay lens at an angle that covers the typical shape of the head (as shown in FIGS. 8 and 9). In some cases, the second mirror is a partially transmissive optical device to filter out unwanted light or transfer it onto an absorption region. The optical device can be directed towards at least the partially reflective surface of the first mirror device. The figure shows a single ray from the theoretical exit pupil for three nominal sets of field angles. It will be understood that a larger exit pupil area results in multiple field angles (i.e., the coverage of the lens and / or mirror by the rays is larger than that shown).

[0042] The optical device is arranged such that an optical path with two folds is defined. The first fold is at the second mirror, and the second fold is at the first mirror. This configuration ensures a small-sized device as shown in FIG. 7. As a result of the two folds included in the overall optical device, some parts of the configuration can be supported on the side of the head during use. This makes the housing of the device smaller and more lightweight, improving the comfort and weight of the device. The wearing of the optical device becomes more practical. In addition, the field of view of the combiner is not interfered with by a large-sized device or a visible device. This can be achieved by tilting the combiner obliquely, i.e., tilting the combiner about a horizontal axis. Such an oblique eyepiece can give the user room to wear personal eyeglasses such as vision correction glasses when sufficiently separated from the user's face. This embodiment provides a combiner pupil distance of 53.5 mm (i.e., the stand-off distance from the eye to the combiner). However, in alternative embodiments, a range of 48 to 59 mm is contemplated.

[0043] 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 configuration further aids in the small-sized shape and can free up space in the region corresponding to the bridge of the user's nose.

[0044] The combiner element 408 is tilted about at least a first axis, in this case the X-axis, and has an aspherical surface shape. The surface shape is also eccentric about the Y-axis, i.e., the central ray in the FOV does not hit the center of the optical surface shape. The combiner is configured to change the direction of one or more wavelengths towards the user in order to enable the user to view simultaneously the virtual display created by the optical device and the external world 414. The combiner 408 is configured to change the direction of the light rays incident on the combiner 408 by using an optical coating applied to at least a portion of the surface of the combiner. The coating is ideally applied over the entire surface, or alternatively, can be applied only to the "optically active" region of the combiner, e.g., the region where light rays are likely to hit the combiner and not elsewhere. The asphericity is used to compensate for off-axis aberrations. Since the combiner is tilted, it induces optical aberrations in the image light.

[0045] Since the combiner is off-axis with respect to the linear optical path, the aberrations are specifically caused, and these aberrations can include spherical aberration, coma, astigmatism, and distortion. The combiner is tilted to correctly change the direction of the light, and if not tilted correctly, the light is not sent towards the eye. Using only a spherical surface shape limits the degree of freedom of optical correction in the design, and the combiner can have a more complex surface shape, e.g., a bi-conical surface shape, and thus additional degrees of freedom can be used to better correct the aberrations caused by the element being tilted.

[0046] Using a bi-conical surface shape has several advantages. Different radii in both the X-axis and Y-axis enable the use of different optical powers in both axes and also enable the introduction of a conical contribution in both the X-axis and Y-axis. The conical contribution changes the spherical to an alternative surface shape, e.g., an ellipse, hyperbola, or parabola that is more eccentric with respect to the shape and helps to compress the light beam of the reflected light into a smaller light beam compared to a typical spherical surface shape, depending on the value of the conical contribution.

[0047] The combiner includes a first optical surface shape on the inner surface 416 of the combiner and a second optical surface shape on the outer surface 418 of the combiner to minimize the deviation with respect to the external field of view 414. The surface shape on the outer surface 418 is described by a set of optical parameters different from those of 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 over the region of the combiner 408. The surface shapes are generally described by different radii and cone constants in the X and Y axes such that the surface shapes are both bi-cones with different optical prescriptions. In some cases, the surface shapes may have additional complexity such that they are described by including a multi-degree polynomial function or an aspherical shape contribution.

[0048] In addition to the optical coating, the combiner 408 is generally configured to change the direction of light by using one of the following optical elements applied over the region of the combiner, namely, a holographic optical element, a diffractive optical element, or an optical microstructure (none of which are shown). Using these optical techniques can provide the system with additional degrees of freedom to change the direction or orientation of the light beam that cannot be achieved using only a reflective coating. Examples of holographic or diffractive optical elements can change the direction of light to more extreme angles without the need to induce additional tilts to the combiner element, according to the laws of diffraction. Additional tilts are required when only reflective optical coatings are used where the design is limited by the laws of reflection.

[0049] In some cases, the combiner 408 is made of a plastic material and includes coatings with various functions as described above. As a result, an efficient and highly transmissive component that is very suitable for use in an extended reality optical design is obtained. In most cases, the combiner has a transmissivity suitable for visually recognizing the extended reality field of view of the symbolology and the external world. When the optical device is used in a virtual environment, the transmissivity of the combiner can be reduced to a value close to zero.

[0050] The first mirror 406 has optical power, and its front surface 420 may be eccentric and tilted. Different combinations of power, tilt, and eccentricity are used depending on the required layout and / or configuration of the device. The first mirror 406 has reflective sides on either side. In the first case, the first mirror comprises a reflective first surface, and light undergoes reflection from the reflective first surface. In a different case, the first mirror includes a transmissive first surface and a reflective second surface, and light passes through the mirror, undergoes reflection from the second surface, and passes through the first surface, in which case the element acts similarly to a conventional lens having a reflective back surface, adding additional degrees of freedom to the design.

[0051] The first mirror 406 is located near the intermediate image plane of the optical design, i.e., the size and shape of the first mirror 406 help to define or limit the field of view of the image presented to the user. When light is not reflected by the mirror, it does not continue to travel towards the combiner and the user's eye; instead, it can be absorbed by the surrounding chassis or support, thereby improving the control of stray light. 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 allows it to be tiltable and rotatable about two or more axes. Configuring the first mirror to be tilted can also help to compensate for the aberrations induced by the tilted combiner.

[0052] The second mirror 412 is tilted at least about a second axis with respect to the axis of the first mirror and includes at least one partially reflective surface on either its inner or outer surface. The second mirror 412 is positioned at or near the aperture position of the system. The aperture position is between the relay lens and the first mirror and is shaped to limit the light that travels to the exit pupil presented to the user by the second mirror by acting as an optical aperture as well.

[0053] The partial reflecting surface of the second mirror partially transmits one or more wavelengths. Thus, the light passing through the optical device is filtered by reflecting only some optical wavelengths in order to limit which wavelengths are sent towards the optical combiner. This can be advantageous because, in contrast to the case where a complete set of wavelengths is emitted by a display or image source, the optical coating applied to the combiner can be optimized to function over a discrete set of wavelengths. This can help the optical coating, for example, by maximizing transmittance across the visible spectrum of wavelengths, to reduce the impact on the user's view of the real world.

[0054] The second mirror can also be extended to enable additional features such as the ability to change the brightness of the virtual content. As an example, the mirror can have an electronically controllable reflectivity or transmittance, whereby the user can control the brightness of the system by electronically controlling either the reflectivity or transmittance to allow more or less light to pass through the device. Alternatively, an electronically controllable filter, such as a liquid crystal device, can be placed on the mirror to enable variable absorption of the incident light, whereby the user can control the brightness of the system by electronically controlling the absorption of either element to allow more or less light to pass through the device.

[0055] The optical absorption region is disposed behind the second mirror such that any transmitted light is preferably absorbed and cannot return to the optical device to reduce stray light.

[0056] As can be seen from FIG. 5, by substantially orthogonally aligning the axes of each mirror, the optical path includes at least two dimensions or axes with double the number of folds. This reduces the overall size of the optical device and further improves in terms of the number of components, weight, and efficiency without sacrificing optical quality.

[0057] 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 includes at least one self-luminous display (not shown) that can activate a plurality of emission 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 called large cone emission and is obtained from a display called a large cone emission device or display. Generally, the cone angle of the emission can be any angle up to about ±90° or much smaller, such as about ±25°, in order to fill the exit pupil of the designed system. For this reason, it is important to correctly control the unwanted cone angles, otherwise the unwanted cone angles may propagate through the optical system and reach the eye.

[0058] The image source is a self-luminous display, a micro-LED array, a multiple display panel, or any other suitable source.

[0059] The image source is tilted with respect to the relay lens at 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 enlarged image. In other cases, multiple image sources may be used and combined using optical filters. For example, instead of a single display panel, discrete red, green, and blue display panels that can emit red, green, and blue light may be used and combined using dichroic filters.

[0060] Instead, in some cases, the optical device is wearable. In these cases, the optical device is housed in a housing attached to a helmet or other wearable frame, or forms an integral part of the helmet or frame. The optical devices in these cases include, for example, head-worn devices (HWDs), head-mounted displays (HMDs), or any other suitable device.

[0061] The content of the augmented image includes symbology associated with the contacts 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, position and positioning symbology, map symbology, speed and velocity symbology, etc. In addition, a full-frame video can be displayed in addition to the symbology.

[0062] The optical device, in some cases, forms part of a system (not shown), which is used to control and 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 environment associated with the vehicle, and a processor for receiving, transmitting, and processing data to determine the data to be displayed to the user by the optical device according to the present invention. The user may be an aircraft pilot, and the system may be an aircraft system.

[0063] The optical device includes relay lenses 404, 600. The relay lenses 404, 600 will be described in more detail below with reference to FIG. 6, which shows several different configurations of lenses 602, 604, and 606. These are three of the many possible configurations. The lenses are made of any suitable material. For weight reduction, the lenses are made of a plastic material or glass in at least some cases. The relay lenses provide further improvements 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 ranging solution is required.

[0064] Relay lens 600 is designed to be as simple as possible while maintaining the required performance level and minimizing cost and the number of components. Each configuration 602, 604, and 606 of relay lens 600 comprises three lenses, namely, two singlets 608, 610 and one doublet 612. At least one or more of the lenses have a non-powered (flat) back surface, in this case singlet 610. It should be further noted that lenses 608 and 612 are arranged as an optical doublet joined to enable a certain level of color correction.

[0065] Accordingly, in particular, a relay lens 600 is provided that comprises a series of coaxial lens elements.

[0066] In the order closest to the image source, the first lens element of the series of lens elements is a plano-convex lens 610 arranged such that its flat back side faces the image source. The second lens element of the series of lens elements is a bi-concave - bi-convex lens doublet lens 612 with both concave portions facing the convex side of the first lens element. The third lens element of the series of lens elements is a bi-convex lens 608.

[0067] Such a relay lens configuration, in combination with the surrounding optical architecture described herein, can obviate the need for additional lens elements elsewhere in the optical path.

[0068] As shown in configuration 602, all lenses are coaxially aligned to simplify and facilitate assembly, but are arranged to deviate from the optical axis of the optical device. This arrangement is achieved through performance optimization, and the lenses are offset and tilted with respect to the axial ray path to correct for the off-axis aberrations induced by the off-axis combiner. Additionally, 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 full field of view.

[0069] As an extension of configurations 602 and 604, it is recognized that during the design, a portion of the lens is unused, and as a result, the tip of the relay lens is cut off so that only some portions of the lens that support the optical path are retained. During the design of multiple lenses, the trajectory of the expected light beam passing through the lenses is identified. Material can be removed from each lens of the multiple lenses that is predicted not to be traversed by the expected light beam. Changes to the lenses within the relay lens are used to update the augmented reality optical design.

[0070] Lens configuration 606 not only is advantageous in reducing mass / volume, but also functions as an additional individual aperture through which light that would normally pass through the upper part of the lens cannot pass. This avoids additional stray light in the optical device. A further measure is, for example, to ensure that the relay lens element has a suitable absorption edge by using black paint. Note that each optical prescription of the lenses within the configuration can be configured as needed to match the required functions.

[0071] The optical device can operate as a monocular device, but the most likely usage is as a binocular configuration as shown in FIG. 7 having two optical devices 402. Each optical device includes an imaging optical system for either the user's right or left eye. As a result, all components can be designed for ambidexterity for simplicity, and the number of discrete parts can be reduced. The optical paths of both eyes on both sides do not cross, and the optical paths of both eyes on both sides are completely separated. This improves configurability and maintenance options and minimizes the risk of crosstalk or stray light between the two eyes. The displays are also completely independent, so if one optical channel fails or is damaged, the user still has access to the remaining display in the other eye, and completely separate content can be provided to both eyes, for example, stereoscopic content can be provided.

[0072] The binocular configuration is supported by a frame, housing, or helmet designed to be worn by the user. As seen in FIG. 7, this is a top-down view, and only the axial light beam is shown for clarity. As shown, the mirror is configured to fold the optical system conveniently around the arc of the head (e.g., around the eyebrows) so that it is away from the user's line of sight upward and does not significantly affect the user's peripheral vision.

[0073] One optical device / each optical device is housed in a housing (not shown). The housing of the head-mounted device should be as lightweight as possible to avoid neck stiffness and other discomfort to the user. The housing not only needs to be small, but also must contain the optical device without any of the optical elements occupying any of the user's FOV. If the optical elements are "obstructive", this can cause accidents and the user's field of vision may become unclear. 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 positioned around the head so as not to block the field of vision. Thus, the optical device is small, compact, lightweight, and does not compromise optical quality and performance.

[0074] 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 a light-emitting display as described above and collected by a relay lens. The relay lens focuses the light towards a second mirror located near the optical aperture of the optical design. The second mirror reflects the light towards a first mirror which also has optical power, and the light is then reflected towards a combiner element. The combiner is configured to be partially transmissive so as to combine the field of view from the outside while partially reflecting the display light towards the user.

[0075] Next, a method of operation of the optical device will be described with reference to the flowchart of FIG. 10.

[0076] The method of operation 1000 of the augmented reality optical design is implemented as follows.

[0077] In step 1002, light is emitted by the image source 424 over a given area and cone angle, and a portion is received by the relay lens assembly 404.

[0078] In step 1004, the relay lens assembly 404 sends light towards an intermediate aperture within the system. Light not transmitted by the relay lens assembly 404 is mainly absorbed within the assembly, thus controlling stray light emitted by the image source.

[0079] 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. Light outside the aperture of the second mirror 412 is not reflected, thus helping to form the exit pupil of the optical device 402.

[0080] In step 1008, the first mirror 406 receives the light, sends it towards the combiner 408, and light outside the aperture of the first mirror 406 is not redirected, thus helping to form the field of view of the optical device 402.

[0081] In step 1010, the combiner 408 receives the light from the first mirror 406, partially changes the direction of the light towards the user, forms an exit pupil at the position of the eye 400, whereby the user can view a virtual display focused between approximately 30 cm and infinity depending on the placement of the relay lens assembly 404 and the positioning of the image source.

[0082] In step 1012, light is directed towards the eye 400 through the exit pupil of the optical device 402, which is partially limited by the shape of the relay lens assembly 404 and the second mirror 212, whereby the risk of viewing stray light or uncorrected portions of the image is minimized if the user moves the eye 400 outside the defined / corrected exit pupil.

[0083] The exit pupil or eyebox is the region within the space where the image appears sharp and in focus because the image is optically well corrected. As the eye moves around this space, the sharpness of the virtual image may change. Specifically, the sharpness may decrease 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 simply correct the image across the exit pupil, as defined by optimization software. Instead, the present invention uses a number of apertures to ensure that due to additional emission from the image source (i.e., a larger cone angle of emission), the pupil cannot become larger than the designed exit pupil.

[0084] There are a number of variations and aspects that may be included within the scope of the claims, and accordingly, it will be understood that these alternatives are intended to be covered by the claims.

[0085] As a further example, an optical device made according to an extended reality optical design, the optical device comprising a plurality of optical elements for transmitting light from a light source onto a user's eye, wherein the optical device comprises a light source for generating light, a lens assembly configured to receive the light with an axis removed from the light source, wherein the lens assembly comprises a series of coaxial lens elements, a first lens element in the series of lens elements being a plano-convex lens with a flat back side facing towards the image source, a second lens element in the series of lens elements being a bi-concave - bi-convex doublet lens with the bi-concave portion facing the concave side of the first lens element, and a third lens element in the series of lens elements being a bi-convex lens, and a combiner for receiving light from the lens assembly via one or more further optical elements of the plurality of optical elements and sending the light to form a virtual image at the exit pupil at the position of the eye. An optical device is provided.

Claims

1. An optical device made according to an augmented reality optical design, the optical device comprising a plurality of optical elements for transmitting light from a light source onto a user's eye, the optical device being a light source for generating the light, a lens assembly having an off-axis axis from the light source and configured to receive the light, wherein the lens assembly includes a plurality of lenses, and wherein the lens assembly has a tip cut off by removing material from one or each of the plurality of lenses where it is predicted that an expected light beam will not pass through, a combiner that receives the light from the lens assembly via one or more additional optical elements of the plurality of optical elements and sends the light to form a virtual image at an exit pupil at the position of the eye. An optical device.

2. The optical device according to claim 1, wherein the lens assembly is a relay lens.

3. The optical device according to claim 1 or 2, wherein the lens assembly comprises three or more lenses.

4. The optical device according to any one of the preceding claims, wherein the lens assembly is made of a plastic material or glass.

5. The optical device according to any one of the preceding claims, wherein the lens assembly comprises a combination of a singlet lens and a doublet lens.

6. The optical device according to any one of the preceding claims, wherein at least one of the plurality of lenses has a non-coated back surface.

7. The optical device according to any one of the preceding claims, wherein at least two of the plurality of lenses are configured as a cemented optical doublet.

8. The optical device according to any one of the preceding claims, wherein the plurality of lenses are arranged coaxially.

9. The optical device according to any one of the preceding claims, wherein each of the plurality of lenses includes an absorption edge.

10. The optical device according to any one of the preceding claims, wherein each of the plurality of lenses has a different optical prescription.

11. The optical device according to any one of the preceding claims, wherein each of the plurality of lenses includes an absorption edge.

12. The one or more additional optical elements of the plurality of optical elements are A first device provided with at least a partially mirror An optical device according to any one of the preceding claims, comprising: a second optical device positioned substantially orthogonally to the first device provided with at least a partially mirror, and located intermediate the lens assembly and the first device provided with at least a partially mirror, the second optical device being configured to receive the light from the lens assembly and transmit the light to the first device provided with at least a partially mirror

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

14. The optical device according to claim 13, wherein each pixel is adapted for illumination and light emission over a wide cone angle greater than ±25°

15. The optical device according to any one of the preceding claims, wherein the optical device is configured to fold an optical path around a first axis (XYZ) and a second axis (XYZ)

16. The optical device according to any one of the preceding claims, forming part of a wearable device, at least a part of the optical device being folded above or to the side of the user's eyebrows

17. An optical device made according to an extended reality optical design, the optical device comprising a plurality of optical elements for transmitting light from a light source onto the user's eye, the optical device comprising a light source for generating the light a lens assembly having an off-axis axis and configured to receive the light, wherein the lens assembly includes a plurality of lenses, and wherein the lens assembly has a tip cut off by removing material from one or each of the plurality of lenses through which a predicted light beam is predicted not to pass A combiner that receives the light from the lens assembly through one or more additional optical elements among the plurality of optical elements and sends the light to form a virtual image at an exit pupil at the position of the eye, wherein the combiner has a first inner optical surface shape and a second outer optical surface shape, wherein the first inner optical surface shape is different from the second inner optical surface, and minimizing the deviation in the outer field of view from the combiner. wherein the one or more additional optical elements among the plurality of optical elements are a first device provided with at least a partially mirror; an optical device that is positioned substantially orthogonally to the first device provided with at least a partially mirror and is located between the lens assembly and the first device provided with at least a partially mirror, and the second optical device is configured to receive the light from the lens assembly and transmit the light to the first device provided with at least a partially mirror.

18. A binocular optical device comprising two optical devices according to any one of the preceding claims.

19. A wearable device including one or two optical devices according to any one of claims 1 to 18.

20. 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 transmit the data to the processor; A system comprising one or more wearable devices according to claim 19.

21. A method of sending light through an optical device made according to an extended reality optical design, wherein the optical device comprises a plurality of optical elements for transmitting light from a light source onto a user's eye, the method comprising: Emitting light to a lens assembly through a light source, wherein the lens assembly includes a plurality of lenses, and wherein the lens assembly has a tip cut off by removing material from one or each of the plurality of lenses where it is predicted that an expected light beam will not pass through. Sending the light towards a combiner element through one or more additional optical devices. Comprising sending the light through the combiner in order to form a virtual image at the exit pupil of the optical device. Here, the combiner has a first inner optical surface shape and a second outer optical surface shape, where the first inner optical surface shape is different from the second inner optical surface, and a method for minimizing the deviation in the outer field of view from the combiner. **Claim 22** Designing the optical device; Determining an optical path through the design; Identifying regions of the lens assembly where light is predicted not to pass through; The method according to claim 21, further comprising updating the design to cut off one or more tips of the plurality of lenses based on where light is predicted to pass through. **Claim 23** The method according to claim 21 or 22, further comprising removing lens material from regions projected not to allow light to pass through in the lens assembly. **Claim 24** The method according to any one of claims 21 to 23, further comprising applying absorption edges to each of the plurality of lenses. **Claim 25** The method according to any one of claims 21 to 24, further comprising joining one or more of the plurality of lenses to each other.

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