JP6873041B2 - A method of manufacturing an eyepiece containing a first diffractive optical element - Google Patents

Description

The present disclosure relates to virtual reality and augmented reality imaging and visualization systems.

Modern computing and display technology is the so-called "virtual reality" in which digitally reproduced images or parts thereof are presented to the user in a manner that appears or can be perceived as reality. Or it is facilitating the development of systems for "augmented reality" experiences. Virtual reality, or "VR" scenarios, typically involve the presentation of digital or virtual image information without transparency to other real-world visual inputs. Augmented reality, or "AR" scenarios, typically involve the presentation of digital or virtual image information as an extension of the visualization of the real world around the user. For example, referring to FIG. 1, an augmented reality scene (4) is depicted, in which users of AR technology feature real-world people, trees, buildings as a background, and a concrete platform (1120). You can see the setting (6) like a park. In addition to these items, users of AR technology will also see a robot image (1110) standing on a real-world platform (1120) and a flying cartoon-like avatar character that looks like an anthropomorphic bumblebee. 2) perceives to be "visible", but these elements (2, 1110) do not exist in the real world. In conclusion, the human visual perception system is very complex, a VR or AR technology that promotes a comfortable, natural-like and rich presentation of virtual image elements among other virtual or real-world image elements. Is difficult to generate.

When presenting 3D virtual content to users of an AR system, there are many problems. The main premise of presenting 3D content to the user involves the generation of perceptions of multiple depths. In other words, it may be desirable for some virtual content to appear closer to the user, while other virtual content appear to occur farther. Therefore, in order to achieve 3D perception, the AR system should be configured to deliver virtual content to the user in different focal planes.

The 3D display generates an accommodation response for each point in the field of view of the display to provide a true sense of depth, more specifically a simulated sense of surface depth. It is desirable to do. If the accommodation response to a display point does not correspond to the virtual depth of the point, which is determined by the depth cues of both eyes in convergence and stereoscopic vision, the human visual system experiences an accommodation collision and is unstable. In the absence of imagery, adverse eye strain, headache, and accommodation information, it can result in an almost complete lack of surface depth.

Therefore, there is a need for improved technology to implement 3D displays that solve these and other problems of the traditional approach. The systems and techniques described herein are configured to address these challenges in conjunction with the typical human visual configuration.

Embodiments of the invention cover devices, systems, and methods for facilitating virtual reality and / or augmented reality interactions for one or more users.

An augmented reality (AR) display system for delivering augmented reality content to a user, according to some embodiments, is an image source for providing one or more frames of image data and one or more of the image data. With an optical modulator to transmit the light associated with the frame and a diffractive optical element (DOE) to receive the light associated with one or more frames of image data and direct the light to the user's eye. The DOE is a waveguide substrate, a surface lattice, and an intermediate layer (also referred to as a “lower layer” in the present specification) arranged between the waveguide substrate and the surface lattice corresponding to the refractive index of the waveguide. The lower layer is provided with a DOE corresponding to a lower layer diffraction index different from the refractive index of the waveguide.

According to some embodiments of the present invention, the diffraction structure is employed for DOE, including a lower layer between the waveguide substrate and the upper lattice surface. The upper lattice surface is provided with a first material corresponding to the first refractive index value, the lower layer is provided with a second material corresponding to the second refractive index value, and the substrate is provided with the third refractive index value. It has a corresponding third material.

Any combination of the same or different materials can be employed to mount each of these parts of the structure, eg, all three materials are different (and all three materials correspond to different index values). ), Or two of the layers share the same material (eg, two of the three materials are the same and therefore have a common index of refraction that differs from the index of refraction of the third material. Share the value). Any suitable set of materials can be used to mount any layer of improved diffraction structure.

Therefore, various combinations are available, one index of refraction underlayer is combined with another index of refraction upper grid, along with a third index of refraction substrate, and adjustment of these relative values is an angle of incidence. It provides a lot of variation in the dependence of the refractive index on. Layered waveguides with layers of different indices of refraction are presented. Various combinations and permutations are presented with relevant performance data to illustrate functionality. An advantage is the increase in angle, which uses a grid to provide an increase in output angle and thus an eyepiece to provide an increase in field of view. Moreover, the ability to counter the normal reduction in diffraction efficiency with angle is functionally beneficial.

According to additional embodiments, an improved approach is provided to implement the transfer of transfer material onto a substrate, as well as the transfer of transfer material to a pattern for mounting diffraction. These approaches allow for very precise distribution, deposition, and / or formation of different transfer materials / patterns on any number of substrate surfaces. According to some embodiments, a patterned distribution of transfer material (eg, a patterned inkjet distribution) is made to implement the deposition of transfer material on a substrate. This approach, which uses a patterned inkjet distribution, allows for very precise volume control over the material to be deposited. In addition, this approach can serve to provide a smaller, more uniform base layer beneath the lattice surface.

In some embodiments, a template is provided that has a first set of deeper depth structures as well as a second set of shallower depth structures. When depositing the transfer material on the transfer receiving side, a relatively larger volume of transfer material is deposited corresponding to the deeper depth structure of the template. In addition, a relatively smaller volume of transfer material is deposited corresponding to the shallower depth structure of the template. This approach allows simultaneous deposition of materials of different thicknesses because different features are formed on the transfer receiving side. This approach is intended to produce distributions that are intentionally non-uniform due to structures with different depths and / or feature parameters, eg, feature structures are on the same substrate and have different thicknesses. Can be It can be used, for example, to generate a spatially distributed volume of transfer material that allows simultaneous transfer of variable depth structures with the same underlayer thickness.

Some embodiments relate to approaches for implementing simultaneous deposition of multiple types of transfer material on a substrate. This allows materials with optical properties to be deposited simultaneously over multiple parts of the substrate at one time. This approach also has the ability to adjust the local area associated with a particular function (eg, to act as an internally coupled lattice, an orthogonal pupil magnifying element (OPE) lattice, or an exit pupil expanding element (EPE) lattice). provide. Different types of materials can include the same material with different optical properties (eg, two variants of the same material with different refractive indexes) or two completely different materials. Any optical properties of the material, such as refractive index, opacity, and / or absorbance, can be considered and selected when adopting the technique.

According to another embodiment, multi-sided transfer is employed and can be transferred to multiple sides of the optical structure. This allows transfer to occur on different sides of the optics and implement functional multiplexing through the base layer volume. In this method, different eyepiece functions can be implemented without adversely affecting the lattice structure function. The first template can be used to generate a transfer on the substrate / transfer receiving side side surface "A" and form a first pattern with the first material on the side surface A of the structure. Another template can be used to generate a second transfer on the side surface "B" of the same substrate, which forms a second pattern with the second material on the side surface B of the substrate. Sides A and B may have the same or different patterns and / or may have the same or different types of material.

Additional embodiments relate to multilayer multiple transfer and / or multilayer separation / offset substrate integration. With either or both of these approaches, previously transcribed patterns can be ejected and printed again. The adhesive can be ejected onto the first layer, the second substrate is joined to it (possibly with voids), and the subsequent ejection process deposits and transfers on the second substrate. Can be done. A series of transferred patterns can be sequentially joined together in a roll-to-roll process. Note that the approach of implementing multi-layer multiple transfer can be used with or instead of the multi-layer separation / offset substrate integration approach. For multilayer multiple transfer, the first transfer material is deposited on the substrate and transferred, followed by the deposition of the second transfer material, both the first transfer material and the second transfer material. It is possible to provide a composite multilayer structure having a structure. For multi-layer separation / offset substrate integration, both the first substrate 1 and the second substrate 2 can be transferred with the transfer material, after which the substrate 1 and substrate 2 will probably have voids in one embodiment. It can be narrowed and joined with an offset feature (also transferred) provided between the active structure of the substrate 2 and the back side of the substrate 1. The transferred spacers can be used to create voids.

Yet another embodiment discloses an approach for implementing variable volume deposition of materials distributed across substrates, which may rely on a priori knowledge of surface heterogeneity. This compensates for the surface non-uniformity of the substrate, which can result in undesired parallelism and poor optical performance. Variable volume deposition of transfer material can be employed to provide a horizontal distribution of transfer material to be deposited, independent of underlying topography or physical feature sets. For example, the substrate is pulled flat by a vacuum chuck and in-situ measurements can be made to assess surface height, for example using a low coherence or laser-based contact measurement probe. The distributed volume of the transfer material can be varied depending on the measured data, resulting in a more uniform layer depending on the reproduction. Any type of non-uniformity, such as thickness variation and / or dents, peaks, or other anomalies, or the presence of features associated with local location on the substrate, can also be addressed by this embodiment of the invention.

Note that any of the aforementioned embodiments can be combined together. In addition, additional and other purposes, features, and advantages of the invention are described in the embodiments, figures, and claims for carrying out the invention.
For example, the present application provides the following items.
(Item 1)
A method of manufacturing diffractive optics
Placing one or more sets of materials on a substrate,
Identifying a template, wherein the template has a transfer pattern formed on it.
Using the template to transfer the transfer pattern into the set of one or more materials on the substrate.
Including
The method, wherein the transfer pattern comprises a diffraction pattern for the diffractive optical element.
(Item 2)
The set of one or more materials on the substrate comprises a first portion of the material and a second portion of the material.
The template comprises a first set of depth structures and a second set of depth structures, the first set of depth structures having a different depth than the second set of depth structures.
The transfer pattern comprises a first pattern and a second pattern.
Simultaneously forming the first pattern and the second pattern on the substrate, the template comprises the first pattern with the set of the first depth structures on the first portion of the material. The method of item 1, wherein the template transfers the second pattern with the set of the second depth structure onto the second portion of the material.
(Item 3)
The method according to any one of items 1 and 2, wherein the first pattern corresponds to a first diffraction grating pattern, and the second pattern corresponds to a second diffraction grating pattern.
(Item 4)
The method according to any one of items 1 to 3, wherein the first and second portions of the material correspond to a non-uniform distribution of the material on the substrate.
(Item 5)
The method according to any one of items 1 to 4, wherein the substrate forms a uniform thickness lower layer, and the first and second patterns form a variable depth structure on the uniform thickness lower layer.
(Item 6)
The set of one or more materials on the substrate comprises a first portion of the material and a second portion of the material, the first portion of the material being different from the second portion of the material. The method according to any one of items 1 to 5, which has optical characteristics.
(Item 7)
The method according to any one of items 1 to 6, wherein the different optical properties between the first portion of the material and the second portion of the material correspond to different refractive indexes, opacity, or absorbances. ..
(Item 8)
The method of any of items 1-7, wherein the first portion of the material is deposited above the second portion of the material prior to transfer.
(Item 9)
The set of one or more materials on the substrate comprises a first portion of the material and a second portion of the material, the first portion of the material being on a first surface of the substrate. The second portion of the material is on the second surface of the substrate.
Transferring the first pattern into a first portion of the material on the first surface of the substrate,
Transferring the second pattern into a second portion of the material on the second surface of the substrate,
The method according to any one of items 1 to 8.
(Item 10)
The method according to any one of items 1 to 9, wherein the first pattern is different from the second pattern.
(Item 11)
The method according to any one of items 1 to 10, wherein the first portion of the material is a material different from the second portion of the material.
(Item 12)
The set of one or more materials on the substrate comprises a first portion of the material and a second portion of the material, the first portion of the material being a deposit of the second portion of the material. The method of any of items 1-11, which is previously deposited and transferred.
(Item 13)
The method of any of items 1-12, wherein the transfer is performed on the second portion of the material.
(Item 14)
The method according to any one of items 1 to 13, wherein the first substrate having the first transferred pattern is superposed on the second substrate having the second transfer pattern.
(Item 15)
The method according to any one of items 1 to 14, wherein the first substrate having the first transferred pattern is joined to the second substrate having the second transfer pattern.
(Item 16)
Any of items 1 to 15, wherein the spacer forms a gap between the first substrate having the first transferred pattern and the second substrate having the second transferred pattern. The method described in.
(Item 17)
The method of any of items 1-16, wherein variable levels of the one or more sets of materials are deposited on the substrate.
(Item 18)
The method of any of items 1-17, wherein the variable level of the set of one or more materials deposited on the substrate is identified by measuring the variability of the surface uniformity of the substrate. ..
(Item 19)
The method of any of items 1-18, wherein the set of one or more materials is deposited onto the substrate by inkjet deposition.
(Item 20)
A diffractive optical element formed using the method according to any of items 1-19.

FIG. 1 illustrates a view of an augmented reality (AR) user through a wearable AR user device in one illustrated embodiment. FIG. 2 illustrates a conventional stereoscopic 3D simulation display system. FIG. 3 illustrates an improved approach for implementing a stereoscopic 3D simulation display system according to some embodiments of the present invention. FIG. 4A-4D illustrates various systems, subsystems, and components for addressing the objectives of providing a high quality and comfortably perceived display system for human VR and / or AR. FIG. 4A-4D illustrates various systems, subsystems, and components for addressing the objectives of providing a high quality and comfortably perceived display system for human VR and / or AR. FIG. 4A-4D illustrates various systems, subsystems, and components for addressing the objectives of providing a high quality and comfortably perceived display system for human VR and / or AR. FIG. 4A-4D illustrates various systems, subsystems, and components for addressing the objectives of providing a high quality and comfortably perceived display system for human VR and / or AR. FIG. 5 illustrates a plan view of an exemplary configuration of a system utilizing the improved diffraction structure. FIG. 6 illustrates a stacked waveguide assembly. FIG. 7 illustrates DOE. 8 and 9 illustrate exemplary diffraction patterns. 8 and 9 illustrate exemplary diffraction patterns. FIGS. 10 and 11 illustrate two waveguides into which a beam is injected. FIGS. 10 and 11 illustrate two waveguides into which a beam is injected. FIG. 12 illustrates a stack of waveguides. FIG. 13A illustrates an exemplary approach for mounting a diffraction structure with a waveguide substrate and an upper lattice surface but without a lower layer. FIG. 13B shows a chart of exemplary simulation results. FIG. 13C shows an annotated version of FIG. 13A. FIG. 14A illustrates an exemplary approach for mounting a diffraction structure with a waveguide substrate, a lower layer, and an upper lattice surface. FIG. 14B illustrates an exemplary approach for mounting a diffraction structure with a waveguide substrate, lower layer, lattice surface, and upper surface. FIG. 14C illustrates an exemplary approach for mounting a stack of diffractive structures with a waveguide substrate, a lower layer, a lattice surface, and an upper surface. FIG. 15A illustrates an exemplary approach for mounting a diffraction structure with a high index waveguide substrate, a low index lower layer, and a low index upper lattice surface. FIG. 15B shows a chart of exemplary simulation results. FIG. 16A illustrates an exemplary approach for mounting a diffraction structure with a low index waveguide substrate, a high index lower layer, and a low index upper lattice surface. FIG. 16B shows a chart of exemplary simulation results. FIG. 17A illustrates an exemplary approach for mounting a diffraction structure with a low index waveguide substrate, a medium index lower layer, and a high index upper lattice surface. FIG. 17B shows a chart of exemplary simulation results. FIGS. 18A-D illustrate the modification of lower layer characteristics. FIGS. 18A-D illustrate the modification of lower layer characteristics. FIGS. 18A-D illustrate the modification of lower layer characteristics. FIGS. 18A-D illustrate the modification of lower layer characteristics. FIG. 19 illustrates an approach for implementing precise variable volume deposition of transfer material on a single substrate. FIG. 20 illustrates approaches and transfer steps for implementing directional co-deposition of a plurality of different transfer materials within the same layer, according to some embodiments. 21A-B illustrate an exemplary approach for implementing two-sided transfer in the context of total internal reflection diffractive optics. FIG. 22 illustrates a structure formed using the approach shown in FIGS. 21AB. FIG. 23 illustrates an approach for implementing multilayer multiple transfer. FIG. 24 illustrates an approach for implementing multi-layer separation / offset substrate integration. FIG. 25 illustrates an approach for implementing variable volume deposition of material distributed over a substrate to address surface inhomogeneity.

According to some embodiments of the present invention, a diffractive structure is employed and the diffractive structure includes a lower layer / intermediate layer between the waveguide substrate and the upper lattice surface. The upper lattice surface is provided with a first material corresponding to the first refractive index value, the lower layer is provided with a second material corresponding to the second refractive index value, and the substrate is provided with the third refractive index value. It has a corresponding third material.

One advantage of this approach is that the structure is more widely incident due to the fact that the minimum total internal reflection angle is reduced as the index of refraction is increased by proper selection of the relative index of refraction for the three layers. It is to be able to get a wider field of view for light. Diffraction efficiency is increased and can allow the output of "brighter" light to the display of the image viewing device.

Various combinations are available, one index of refraction underlayer is combined with another index of refraction upper grid, along with a third index of refraction substrate, and adjusting these relative values is an angle of incidence. It provides a lot of variation in the dependence of the refractive index on. Layered waveguides with layers of different indices of refraction are presented. Various combinations and permutations are presented with relevant performance data to illustrate functionality. Advantages include an increase in angle, which uses a grid to provide an increase in output angle and thus an eyepiece to provide an increase in field of view. Moreover, the ability to counter the usual reductions in diffraction efficiency with angle is functionally beneficial.

(Display system according to some embodiments)
This part of the disclosure describes an exemplary display system that can be used in conjunction with the improved diffraction structure of the present invention.

FIG. 2 typically illustrates a conventional stereoscopic 3D simulation display system with separate displays 74 and 76 for each eye 4 and 6, respectively, at a fixed radial focal length of 10 from the eye. This conventional approach cannot take into account many of the useful cues used by the human eye and brain to detect and interpret depth in three dimensions, including accommodation cues.

In fact, the typical human eye can interpret multiple depth layers based on radial distances, for example about 12 depth layers. A near-field limit of about 0.25 meters is near the closest depth of focus, and a far-field limit of about 3 meters means that any item more than about 3 meters away from the human eye will receive infinite focus. To do. The layer of focus becomes thinner and thinner as it gets closer to the eye. In other words, the eye is able to perceive a very small focal length difference the closer it is to the eye, and this effect dissipates as the object moves further away from the eye. At infinite object locations, the depth of focus / light refraction interval value is about 1/3 diopter.

FIG. 3 illustrates an improved approach for implementing a stereoscopic 3D simulation display system according to some embodiments of the invention, with two composite images, one for each eye 4 and 6. Displayed one by one, different radial focal depths (12) for different aspects (14) of each image are utilized to provide a perception of three-dimensional depth stratification within the image perceived by each eye. obtain. Since there are multiple focal planes (eg, 12 focal planes) between the user's eye and infinity, the data in these focal planes and the relationships depicted makes the virtual element visible to the user. It can be used to position it within an augmented reality scenario. This is because the human eye constantly moves around and uses the focal plane to perceive depth. Although this figure shows a particular number of focal planes at various depths, implementations of the present invention may use any number of focal planes as needed for the particular application desired. Therefore, it should be noted that is not limited to devices having only a specific number of focal planes shown in any of the figures in the present disclosure.

With reference to FIGS. 4A-4D, some general component choices according to some embodiments of the present invention are illustrated. In part of the detailed description following the discussion of FIGS. 4A-4D, various systems, subsystems, and components provide a high quality and comfortable perceived display system for human VR and / or AR. Presented to address the purpose.

As shown in FIG. 4A, an AR system user (60) is depicted wearing a frame (64) structure coupled to a display system (62) located in front of the user's eyes. In the depicted configuration, the speaker (66) is coupled to the frame (64) and positioned adjacent to the user's ear canal (in one embodiment, another speaker (not shown) is adjacent to the user's other ear canal. Positioned to provide stereo / moldable sound control). The display (62) is operably coupled to the local processing and data module (70) by a wired lead or wireless connection (68), and the data module (70) is fixedly attached to the frame (64). , As shown in the embodiment of FIG. 4B, fixedly attached to a helmet or hat (80), embedded in headphones, as shown in the embodiment of FIG. 4C, in a backpack configuration. Removably attached to the body (82) of 60), or detachably attached to the waist (84) of the user (60) in a belt-coupled configuration, as shown in the embodiment of FIG. 4D, etc. It can be mounted in various configurations.

The local processing and data module (70) may include a power saving processor or controller and digital memory such as flash memory, both of which can be utilized to assist in data processing, caching, and storage. Data is from a) sensors that can be operably coupled to the frame (64), such as image capture devices (cameras, etc.), microphones, inertial measurement units, accelerometers, compasses, GPS units, wireless devices, and / or gyroscopes. Captured data and / or b) Perhaps acquired and / or processed using a remote processing module (72) and / or a remote data repository (74) for passing to display (62) after processing or reading. It is the data that was made. The local processing and data module (70) can be operably coupled to the remote processing module (72) and the remote data repository (74) via a wired or wireless communication link or the like 76,78), these remote modules ( 72, 74) are operably coupled to each other and are available as resources for local processing and data module (70).

In one embodiment, the remote processing module (72) may include one or more relatively powerful processors or controllers configured to analyze and process data and / or image information. In one embodiment, the remote data repository (74) may be equipped with relatively large digital data storage equipment that may be available through the Internet or other networking configurations in a "cloud" resource configuration. In one embodiment, in local processing and data modules, all data is stored, all calculations are performed, and fully autonomous use from any remote module is possible.

Perception of the Z-axis difference (ie, the linear distance from the eye along the optical axis) can be facilitated by waveguideing with a variable focus optics configuration. Image information from the display can be collimated, populated into a waveguide, and distributed in a large exit pupil fashion using any suitable substrate induction optical method known to those of skill in the art, and then variable focus. Optical element capabilities can be used to change the focus of the wave front of light emerging from a waveguide and to provide the eye with the perception that the light originating from the waveguide is from a particular focal length. In other words, the incident light is collimated to avoid problems in the all-internally reflected waveguide configuration, so that it is emitted in a collimated manner and the viewer's eye adjusts the perspective to a distant point. As it is from optical infinity, unless it requires that it be focused on the retina and, inevitably, some other intervention causes the light to be refocused and perceived as from different viewing distances. Will be interpreted. One such intervention that is preferred is a varifocal lens.

In some embodiments, the collimated image information is injected into a piece of glass or other material at an angle such that it is totally internally reflected and passed through the adjacent waveguide. The waveguide may be configured such that the collimated light from the display is distributed along the length of the waveguide so that it is emitted substantially uniformly over the distribution of reflectors or diffraction features. Upon exit to the eye, the emitted light is passed through the varifocal lens element and, depending on the controlled focus of the varifocal lens element, exits the varifocal lens element and the light incident on the eye is of varying levels. It will have a focal point (the collimated flat wave surface represents optical infinity, and the greater the beam divergence / wave surface curvature, the closer the viewing distance to the eye 58).

In a "frame-sequential" configuration, a stack of sequential 2D images is sequentially fed to the display in a format similar to that in which a computed tomography system uses stacked image slices to represent a 3D structure. Perceptions can be generated over time. A series of 2D image slices can be presented to the eye, each with a different focal length to the eye, and the eye / brain will integrate such a stack into the perception of a coherent 3D volume. Depending on the display type, row-by-row or even pixel-by-pixel ordering can be done to generate a three-dimensional visual perception. For example, in a scanning optical display (such as a scanning fiber display or a scanning mirror display), the display presents the waveguide in a sequential manner, one line or one pixel at a time.

Referring to FIG. 6, the stacked waveguide assembly (178) has a plurality of waveguides (182, 184, 186, 188, 190) and a plurality of weak lenses (198, 196, 194, 192). Thereby, it can be utilized to provide three-dimensional perception to the eye / brain, with multiple waveguides and multiple weak lenses each waveguide indicating the focal distance to be perceived for that waveguide level. It is configured together to transmit image information to the eye with various levels of waveguide curvature for the tube level. Multiple displays (200, 202, 204, 206, 208), or in another embodiment, a single multiplexed display was collimated into the waveguide (182, 184, 186, 188, 190). It can be used to input image information, and each of the waveguides is configured to distribute incident light substantially equally over the length of each waveguide for exit to the eye, as described above. Can be done.

The waveguide closest to the eye (182) is configured to deliver collimated light to the eye that may represent an optical point at infinity plane as it is inserted into such a waveguide (182). Ru. The next upper waveguide (184) is to transmit collimated light through a first weak lens (192; eg, a weak negative lens) before it can reach the eye (58). It is composed. In such a first weak lens (192), the eye / brain produces light from the next upper waveguide (184) from a first focal plane that is closer inward inward from optical infinity. It can be configured to create a slight convex wavefront curvature, as interpreted as. Similarly, the third upper waveguide (186) allows its output light to pass through the first (192) and second (194) lenses before reaching the eye (58). The combined refractive power of the first (192) and second (194) lenses allows the eye / brain to direct the light generated from the third waveguide (186) above it to the next upward waveguide ( It may be configured to create another gradual wavefront divergence, interpreted as originating from a second focal plane that is even more inward toward the person from optical infinity than the light from 184). ..

Other waveguide layers (188, 190) and weak lenses (196, 198) are similarly constructed, with the highest waveguide (190) in the stack having a total focal force representing the focal plane closest to the person. Therefore, its output is transmitted through all of the weak lenses between it and the eye. Compensating lens layer to compensate for the stack of lenses (198, 196, 194, 192) when viewing / interpreting light originating from the other side world (144) of the stacked waveguide assembly (178). (180) is placed at the top of the stack to compensate for the total refractive power of the lower lens stack (198, 196, 194, 192). Such a configuration again provides a relatively large exit pupil configuration for the same number of perceived focal planes as the available waveguide / lens pairs, as described above. Both the reflective side of the waveguide and the focusing side of the lens can be static (ie, not dynamic or electrically active). In an alternative embodiment, it is dynamic and uses electrically active features, as described above, allowing a small number of waveguides to be multiplexed in a time series manner to produce a larger number of effective focal planes. obtain.

Various diffraction configurations can be employed to focus and / or reorient the collimated beam. For example, passing a collimated beam through a linear diffraction pattern such as a Bragg grating would deflect, or "steer," the beam. Passing the collimated beam through a radial symmetric diffraction pattern, the "Fresnel zone plate", will change the focus of the beam. A combined diffraction pattern with both linear and radial elements can be employed to produce both deflection and focusing of the collimated input beam. These deflection and focusing effects can be generated in reflective and transmissive modes.

These principles can be applied with waveguide configurations to allow additional optics control. As shown in FIG. 7, the diffraction pattern (220), i.e. the "diffractive optics" (or "DOE"), is reflected entirely internally along the planar waveguide (216) as the collimated beam is reflected entirely internally. , It is embedded in the planar waveguide (216) so that it intersects the diffraction pattern (220) in many places. The structure can also include another waveguide (218) into which the beam can be directed (eg, by a projector or display), and the DOE (221) is within this other waveguide (218). Be embedded.

Preferably, the DOE (220) is deflected towards the eye (58) using only a portion of the light of the beam at each intersection of the DOE (220), while the rest is deflected through total internal reflections. It has a relatively low diffraction efficiency so that it continues to move through the planar waveguide (216). The light carrying the image information is therefore divided into several related light beams emanating from the waveguide in many places and the results are within the planar waveguide (216), as shown in FIG. A very uniform pattern of emission and emission towards the eye (58) for this particular collimated beam that bounces off. The exit beam towards the eye (58) is shown in FIG. 8 as substantially parallel in this case, as DOE (220) has only a linear diffraction pattern. However, this change to the linear diffraction pattern pitch can be utilized to controlably deflect the emitted collimated beam, thereby producing scanning or tile display functionality.

Referring to FIG. 9, with the change of the radial symmetric diffraction pattern component of the embedded DOE (220), the emitted beam pattern becomes more divergent, which allows the eye to adjust the perspective for a closer distance. It requires the exit beam pattern to be focused on the retina, which will be interpreted by the brain as light from a viewing distance closer to the eye than optical infinity.

With reference to FIG. 10, with the addition of another waveguide (218) in which the beam can be injected (eg, by a projector or display), this other waveguide (218), such as a linear diffraction pattern. The DOE (221) embedded within may function to diffuse light throughout the larger planar waveguide (216), which, according to the particular DOE configuration in operation, is the larger planar waveguide. It functions to provide the eye (58) with a very large incident field of incident light emitted from 216), eg, a large eyebox.

The DOE (220, 221) is depicted to bisect the associated waveguide (216, 218), but this does not have to be. They can also be installed closer to or on either side of any of the waveguides (216, 218) so that they have the same functionality. Thus, as shown in FIG. 11, with the injection of a single collimated beam, the entire field of the cloned collimated beam can be directed towards the eye (58). In addition, in combined linear diffraction pattern / radial symmetric diffraction pattern scenarios such as those described above, beam distribution wavefront optics with Z-axis focusing capability (for functionality such as functional expansion of exit pupils). , In their configuration of FIG. 11, the exit pupil can be the same size as the optics themselves, which can be a very significant advantage for user comfort and ergonomics), but presented. The divergence angle of the cloned beams and the wavefront curvature of each beam both represent light originating from a point closer than optical infinity.

In one embodiment, the one or more DOEs can be switched between an actively diffracting "on" state and a non-significantly diffracting "off" state. For example, the switchable DOE may include a layer of polymer-dispersed liquid crystal, in which the microdroplets have a diffraction pattern in the host medium and the index of refraction of the microdroplets is host. Can it be switched to substantially match the index of refraction of the material (in which case the pattern does not significantly diffract the incident light), or the microdroplets have a index of refraction that does not match that of the host medium. It can be switched (in which case the pattern actively diffracts the incident light). In addition, beam scanning or tile display functionality can be achieved with dynamic changes to the diffraction term. As mentioned above, it is desirable that each of the DOEs (220, 221) have a relatively low diffraction grating efficiency. This is because it promotes the distribution of light, and moreover, the light coming through the waveguide, which is desirable to be transmitted (for example, in an augmented reality configuration, the light generated from the world 144 toward the eye 58) If the diffraction efficiency of the DOE (220) at which it intersects is lower, it is less affected, and therefore a better view of the real world is achieved through such a configuration.

Configurations such as those illustrated herein are preferably driven with the input of image information in a time series approach, with frame sequential drive being the easiest to implement. For example, an image of the sky at optical infinity can be input in time 1, and a diffraction grating that retains light collimation can be utilized. Images of closer tree branches can then be input at time 2, while DOE gives controllable focal length changes, eg, 1 diopter or 1 meter away, and the eye / brain receives light information on the branches. It provides the perception that it results from a closer focal length. This kind of paradigm can be repeated in a fast time series manner so that the eye / brain perceives that the input is all parts of the same image. This is just an example of two focal planes. Preferably, the system will include more focal planes and will provide a smoother transition between the object and its focal length. This type of configuration generally assumes that the DOE is switched at a relatively slow rate (ie, in sync with the frame rate of the display that populates the image within the range of tens to hundreds of cycles / second).

The opposite is that the DOE element can shift the focus over tens to hundreds of MHz and as the pixels are scanned into the eye (58) using a scanning optical display type approach. , It may be a configuration that promotes switching of the focal state of the DOE element on a pixel-by-pixel basis. This means that the overall display frame rate can be kept very low (low enough to ensure that "flicker" is not an issue (in the range of about 60-120 frames / sec)). It means, so it is desirable.

Between these ranges, if the DOE can be switched at the KHz rate, the focus on each scanline can be adjusted on a line-by-line basis, which tells the user, for example, the temporal artifacts in eye movement to the display. It can give a visible advantage from the point of view. For example, different focal planes in a given scene can be interleaved in this way to minimize visible artifacts in response to head movements (as discussed in detail later in this disclosure). A row-by-line focus modulator can be operably coupled to a line-scanning display such as a grating light valve display, in which a linear array of pixels is swept to form an image. The row-by-row focus modulator can be operably coupled to a scanning light display such as a fiber scanning display and a mirror scanning light display.

A stacked configuration similar to that of FIG. 6 may use dynamic DOE to provide multi-plane focusing at the same time. For example, with three simultaneous focal planes, the primary focal plane (eg, based on the measured accommodation) can be presented to the user with a + margin and a-margin (ie, one closer focal plane, One farther focal plane) can be utilized to provide a large focal range that allows the user to adjust the perspective before the plane needs to be updated. This increased focus range can provide a temporal advantage when the user switches to a closer or farther focus (ie, as determined by accommodation measurements), and the new focus plane is centered. The depth of focus can be + and-margins are again prepared for fast switching to either one while the system catches up.

Referring to FIG. 12, collimated images each having reflectors (254, 256, 258, 260, 262) at the ends and inserted at one end by a display (224, 226, 228, 230, 232). Planar waveguides (244, 246,) configured such that information is bounced off by total internal reflections to the reflector, at which point some or all of the light is reflected toward the eye or other target. A stack (222) of 248, 250, 252) is shown. Each of the reflectors can all have slightly different angles so that the emitted light is reflected towards a common destination such as the pupil. Lenses (234, 236, 238, 240, 242) can be inserted between the display and the waveguide for beam steering and / or focusing.

As mentioned above, objects at optical infinity create a substantially plane wavefront, while objects closer, such as 1 m from the eye, create a curved wavefront (with a convex radius of curvature of about 1 m). The optical system of the eye has sufficient power to bend the incident light of light so that it is finally focused on the retina (the convex wavefront is transformed into a concave surface and then to the focal point on the retina). Must have. These are the basic functions of the eye.

In many of the aforementioned embodiments, the light directed at the eye will be treated as part of one continuous wavefront, some of which will collide with the pupil of a particular eye. In another approach, the light directed to the eye can be effectively discretized or divided into multiple beamlets or individual rays, each of which can be functionally created by a beamlet or set of rays. As part of the larger collective wavefront, it has a diameter of less than about 0.5 mm and a unique propagation path. For example, a curved wavefront is approximated by aggregating multiple individual neighboring collimated beams that approach the eye from an appropriate angle to represent an origin, each of which coincides with the center of the radius of curvature of the desired aggregate wavefront. obtain.

When the beamlet has a diameter of about 0.5 mm or less, it is as if it arises through a pinhole lens configuration, which means that each individual beamlet is always independent of the accommodation state of the eye. It is in relative focus on the retina, however, which means that the orbit of each beamlet will be affected by the accommodation state. For example, if the beamlet approaches parallel to the eye and represents a discrete collimated aggregate wave front, then the eye, which is properly accommodated to infinity, will all converge to the same shared spot on the retina. , Will deflect the beamlet and appear in focus. If the eye adjusts to, for example, 1 m, the beam will converge to a spot in front of the retina, cross the pathway, hit multiple neighboring or partially overlapping spots on the retina, and appear blurred.

If the beamlet is close to the eye in a divergent configuration and the shared origin is 1 meter from the viewer, a 1 m accommodation will direct the beam to a single spot on the retina and appear in focus. Let's go. If the viewer adjusts to infinity, the beamlet will converge to a spot behind the retina, producing multiple neighboring or partially overlapping spots on the retina, producing a blurred image. More generally, accommodation of the eye determines the multiplicity of spots on the retina, and a given pixel is "focused" when all of the spots are directed to the same spot on the retina. "Cage", "out of focus" when the spots are offset from each other. This notion that all beamlets with a diameter of 0.5 mm or less are always in focus and can be assembled to be perceived by the eye / brain as if they were substantially identical to the coherent wavefront. It can be used to generate configurations for comfortable 3D virtual or augmented reality perception.

In other words, a set of narrow beams can be used to mimic the condition of using a larger diameter varifocal beam, and if the beamlet diameter is kept up to about 0.5 mm, compare if necessary. The beamlet angular trajectory may be selected to create an effect similar to a larger defocused beam in order to maintain a static focus level and generate an out-of-focus perception (such defocusing). The process may not be the same as the Gaussian blur process, such as for larger beams, but will create a multifocal point spread function that can be interpreted in a similar manner to Gaussian blur).

In some embodiments, the beamlet is not mechanically deflected to form this collective focus effect, but rather the eye, both at multiple angles of incidence and at multiple locations where the beamlet intersects the pupil. Receives an upper set of many beamlets, including. Part of a beamlet from the upper set (emitted from the same shared origin in space) with the appropriate incident angle and intersection with the pupil to represent a given pixel from a particular viewing distance (Like) are turned on with matching colors and intensities to represent the aggregate wave front, while beamlets in the upper set that are inconsistent with the shared origin are not turned on with their colors and intensities. (However, some of them can be turned on at some other color and intensity level to represent different pixels, for example).

Here, with reference to FIG. 5, an exemplary embodiment 800 of an AR system using an improved diffraction structure is described herein. The AR system is generally a waveguide stacked with an image generator 812, at least one FSD808 (fiber scanning device), an FSD circuit 810, coupled optics 832, and the improved diffraction structure described below. Includes at least one optical assembly (DOE assembly 802) with a waveguide. The system may also include an eye tracking subsystem 806. As shown in FIG. 5, the FSD circuit includes an image generator 812 with a Maxim chip CPU 818, a temperature sensor 820, a piezoelectric drive / converter 822, a red laser 826, a blue laser 828, and a green laser 830. , Can include a circuit 810 that communicates with a fiber combiner that combines all three lasers 826, 828, 830. Note that other types of imaging techniques can be used in place of FSD devices. For example, high resolution liquid crystal display (“LCD”) systems, rear-illuminated ferroelectric panel displays, and / or high frequency DLP systems can all be used in some embodiments of the invention.

The image generator is involved in generating the virtual content that is ultimately displayed to the user. The image generator may convert the image or video associated with the virtual content into a format that can be projected to the user in 3D. For example, in generating 3D content, virtual content needs to be formatted so that part of a particular image is displayed on a particular depth plane while others are displayed on another depth plane. There can be. Alternatively, all images can be generated in a particular depth plane. Alternatively, the image generator may be programmed to feed slightly different images to the right and left eyes so that the virtual content appears coherently and comfortably to the user's eyes when viewed together. In one or more embodiments, the image generator 812 delivers virtual content to the optical assembly in a time series fashion. The first part of the virtual scene can be delivered first so that the optical assembly projects the first part in the first depth plane. The image generator 812 can then deliver another part of the same virtual scene, such that the optical assembly projects the second part onto a second depth plane, and so on. Here, the Alvarez lens assembly can be laterally translated quickly enough to generate multiple lateral translations (corresponding to multiple depth planes) on a frame-by-frame basis.

The image generator 812 may further include a memory 814, a CPU 818, a GPU 816, and other circuits for image generation and processing. The image generator can be programmed with the desired virtual content to be presented to the user of the AR system. It should be understood that in some embodiments, the image generator may be housed within a wearable AR system. In other embodiments, the image generator and other circuitry may be housed in a belt pack coupled to wearable optics.

The AR system also includes coupled optics 832 for directing light from the FSD to the optical assembly 802. Coupling optics 832 can refer to one or more conventional lenses used to direct light into a DOE assembly. The AR system also includes an eye tracking subsystem 806 configured to track the user's eye and determine the user's focus.

In one or more embodiments, software blur can be used to induce blur as part of a virtual scene. The blur module can be part of a processing circuit in one or more embodiments. The blur module can blur a portion of one or more frames of image data fed into the DOE. In such an embodiment, the blur module may completely blur a portion of a frame that is not intended to be rendered at a particular depth frame. An exemplary approach that can be used to implement the aforementioned image display system and its components is described in US Patent Application No. 14 / 555,585.

(Improved diffraction structure)
As described above, the collimated beam is totally internally reflected along the planar waveguide, and the diffraction pattern is formed on the planar waveguide so that the beam intersects the diffraction pattern at multiple locations. be able to. This array can be stacked to provide image objects to multiple focal planes in a stereoscopic 3D simulation display system according to some embodiments of the invention.

FIG. 13A is one possibility that can be taken to mount the structure 1300 of the waveguide 1302 (also referred to herein as the “optical guide”, “board”, or “waveguide substrate”). The outcoupling grating 1304 is formed directly on the upper surface of the waveguide 1302, eg, as a combined monolithic structure, and / or both are formed from the same material ( Even if it is not built from the same monolithic structure). In this approach, the index of refraction of the lattice material is the same as the index of refraction of waveguide 1302. The index of refraction n (or "refractive index") of a material describes the extent to which light propagates through its medium and is defined as n = c / v, where c is the speed of light in vacuum and v is. The phase velocity of light in the medium. The index of refraction determines how much light is bent or refracted as it enters the material.

FIG. 13B shows a chart 1320 of exemplary simulation results for a single polarization of the efficiency of light emanating from structure 1300 as a function of the angle at which light is propagating in the waveguide. This chart shows that the diffraction efficiency of coutcoupled light relative to structure 1300 decreases at higher angles of incidence. As can be seen from the figure, at an angle of about 43 degrees, the efficiency drops relatively sharply on the drawn plot due to the total internal reflectance variation based on the angle of incidence in the medium with a uniform index of refraction.

Therefore, the usable range of configuration 1300 is somewhat limited and therefore the bounce interval can be reduced at higher angles of incidence, which is not desirable, which can further reduce the brightness visible to the observer at those angles. It is possible. Diffraction efficiency is lower at the shallowest angles of incidence, which is quite desirable as the bounce intervals between interactions with the top surface (see FIG. 13C) are very large and there is very little opportunity for light to externally bond. Absent. Therefore, a dimming signal with fewer externally coupled samples will result from this arrangement, and this problem is exacerbated by the lattices with lower diffraction efficiency at these high angles using this polarization orientation. Will. Note that as used herein and in the drawings, "1T" refers to the primary transmission diffraction order.

In some embodiments of waveguide-based optical systems or substrate-guided optical systems, such as those described above, different pixels in the substrate-guided image are represented by beams propagating through the waveguide at different angles, and the light is , Propagate along the waveguide by total internal reflection (TIR). The range of beam angles that remain captured within the waveguide by the TIR is a function of the difference in refractive index between the waveguide and the medium outside the waveguide (eg, air). The higher the difference in refractive index, the larger the number of beam angles. In certain embodiments, the range of beam angles propagating along the waveguide correlates with the field of view of the image coupled out of the plane of the waveguide by the diffractive elements and with the image resolution supported by the optical system. Correlate. In addition, the angular range at which total internal reflection occurs is determined by the index of refraction of the waveguide. In some embodiments, the minimum is about 43 degrees and the practical maximum is about 83 degrees, thus in the range of 40 degrees.

FIG. 14A illustrates an approach for addressing this problem, according to some embodiments of the invention, in which structure 1400 is an intermediate layer 1406 between substrate 1302 and upper grid surface 1304 (as used herein). , Called "lower layer 1406"). The upper surface 1304 is provided with a first material corresponding to the first refractive index value, the lower layer 1406 is provided with a second material corresponding to the second refractive index value, and the substrate 1302 is provided with a third refractive index. It has a third material corresponding to the value. Any combination of the same or different materials can be employed to mount each of these parts of structure 1400, eg, all three materials are different (and all three materials correspond to different index values). Or two of the layers share the same material (eg, two of the three materials are the same and therefore have a common index of refraction that differs from the index of refraction of the third material). Please note (share values). Any combination of refractive index values can be adopted. For example, one embodiment includes a low index of refraction for the underlying layer and uses a higher index of refraction value for the surface grid and substrate. Other exemplary configurations with other exemplary combinations of refractive index values are described below. Any suitable set of materials can be used to mount the structure 1500. For example, polymers, glass, and sapphire are all examples of materials that can be selected to mount any of the layers of structure 1400.

As shown in FIG. 15A, in some embodiments, a relatively higher index of refraction substrate is used as the waveguide substrate 1302, with a relatively lower index of refraction lower layer 1406 and a relatively lower index of refraction upper lattice surface. It may be desirable to implement structure 1500 with 1304. It is possible to obtain a wider field of view from the fact that the minimum total internal reflection angle is reduced as the index of refraction is increased through the relationship n1 × sin (θ1) = n2 × sin (90). Because you get it. The critical angle is 41.8 degrees with respect to a substrate having a refractive index of 1.5. However, the critical angle is 36 degrees with respect to the refractive index of 1.7.

A grid formed on a substrate with a higher index of refraction externally couples light, even if it itself has a lower index of refraction, unless the layers of material that make up the grid are too thick between the grid and the substrate. Can be used to This is related to the fact that such a configuration can be used to have a wider range of angles for total internal reflection (“TIR”). In other words, the TIR angle drops to a lower value using such a configuration. In addition, it should be noted that many of the current etching processes may not be very suitable for extending to high index glass. In some embodiments, it is desirable to replicate the outer bond layer reliably and inexpensively.

The configuration of the lower layer 1406 can be adjusted to alter the performance characteristics of the structure 1500, for example by changing the thickness of the lower layer 1406. The configuration of FIG. 15A (the structure comprises a lattice structure 1304 with a relatively low index of refraction material at the top, with an associated lower index of refraction lower layer 1406, which is an associated high index of refraction light induction substrate. (Including 1302) can be modeled to provide data such as those depicted in FIG. 15B. With reference to this figure, plot 1502a on the left relates to a configuration with a zero-thickness underlayer 1502. Center plot 1502b shows data for underlayer 1502 with a thickness of 0.05 micron. Plot 1502c on the right shows data for a 0.1 micron thick lower layer 1502.

As the data in these plots show, as the underlayer thickness increases, the diffraction efficiency as a function of the angle of incidence becomes much more non-linear and suppressed at higher angles, which may be undesirable. Therefore, in this case, lower layer control is an important functional input. However, when using only the zero-thickness underlayer and the lattice features themselves with a lower index of refraction, the range of angles supported by the structure is in the higher index of refraction-based material rather than in the lower index of index material Note that it is dominated by TIR conditions.

With reference to FIG. 16A, an embodiment of structure 1600 featuring a lower layer 1406 with a relatively high index of refraction on a substrate 1302 with a lower index of refraction is illustrated, with the upper surface diffraction grating 1304 being lower than the lower layer 1406 and not necessarily. Although not equal, it has a refractive index comparable to that of substrate 1302. For example, the upper surface grid may correspond to a refractive index of 1.5, the lower layer may correspond to a refractive index of 1.84, and the substrate may correspond to a refractive index of 1.5. For this example, assume that the period is 0.43 μm and λ corresponds to 0.532 μm.

A simulation related to such a configuration is presented in FIG. 16B. As shown in this figure, in chart 1602a with a 0.3 micron thick lower layer 1406, the diffraction efficiency drops as in the configuration described above, but then begins to rise at the higher end points of the angular range. This also applies to the 0.5 micron thick lower layer 1406 configuration, as shown in Chart 1602b. In each of these (0.3 micron, 0.5 micron) configurations, it is beneficial that the efficiency is relatively high in the higher limits of the angular range. Such functionality can tend to counter the more sparse bounce interval concerns mentioned above. Further, shown in this figure is a chart 1602c for an embodiment characterized by an example of 90 degree rotational polarization, where the diffraction efficiency is as low as expected, but steeper compared to shallower angles. It exhibits desirable behavior in that it provides better efficiency at angles.

In fact, in some embodiments, the diffraction efficiency vs. angle can increase at higher angles. This can be a desirable feature for some embodiments as it helps compensate for the lower bounce intervals that can occur at higher propagation angles. Therefore, the structural configuration of FIG. 16A promotes an increase in diffraction efficiency vs. angle at higher angles and may be preferred in embodiments where it is desirable to compensate for lower bounce intervals (caused with higher propagation angles). It is desirable for the monolithic configuration described above.

With reference to FIG. 17A, another structure 1700 is depicted, with the lower layer 1406 having a refractive index substantially higher than that of substrate 1302. The lattice structure 1304 is at the top, and the lattice structure 1304 also has a refractive index higher than that of the lower layer 1406. For example, the upper surface grid can correspond to a refractive index of 1.86, the lower layer can correspond to a refractive index of 1.79, and the substrate can correspond to a refractive index of 1.5. As mentioned above, for this example, assume that the period is 0.43 μm and λ corresponds to 0.532 μm.

With reference to FIG. 17B, chart 1702 shows simulation data exemplified for structure 1700 of FIG. 17A. As shown in Chart 1702, the resulting plot of diffraction efficiency vs. angle of incidence compensates for the lower bounce intervals mentioned above at relatively high angles of incidence and generally possesses reasonable diffraction efficiency over a wider range of angles. Demonstrate the desired general behavior to assist in doing so.

Note that the lower layer 1406 does not have to be uniform across the substrate. Any property of the lower layer 1406 can be varied at different locations on the substrate, such as differences in the thickness, composition, and / or index of refraction of the lower layer 1406. One possible reason for varying the properties of the underlying 1406 is to promote uniform display characteristics in the presence of known variations in either the display image and / or the non-uniform transmission of light within the display system. is there.

For example, consider the case where the waveguide structure receives incident light at a single internal coupling site 1802 on the waveguide, as shown in FIG. 18A. If the incident light is introduced into the waveguide 1302, less and less light will remain as it propagates along the length of the waveguide 1302. This means that the output light near the inner coupling location 1802 can result in appearing "brighter" than the output light farther along the length of the waveguide 1302. If the lower layer 1406 is uniform along the overall length of the waveguide 1302, the optical effect of the lower layer 1406 can enhance this non-uniform brightness level across the substrate.

The properties of the lower layer 1406 can be adjusted over the substrate 1302 to make the output light more uniform. FIG. 18B illustrates an approach in which the thickness of the lower layer 1406 is varied over the length of the waveguide substrate 1302, the lower layer 1406 being thinner near the inner coupling site 1802 and thicker at a distance from the location 1802. Become. Thus, the effect of the lower layer 1406 to promote better diffraction efficiency improves the effect of light loss along the length of the waveguide substrate 1302, at least in part, thereby improving the overall structure. A more uniform light output can be promoted over.

FIG. 18C illustrates an alternative approach in which the thickness of the lower layer 1406 is not variable, but the index of refraction of the lower layer 1406 is variable across the substrate 1302. For example, to address the problem that the output light near location 1802 tends to be brighter at locations away from location 1802, the index of refraction for the lower layer 1406 is the same as or similar to substrate 1302 near location 1802. However, it is configured to have an increasing difference in their index of refraction values at locations away from location 1802. The composition of the underlying 1406 material can be varied at different locations to result in different index values. FIG. 18D illustrates a hybrid approach in which both the thickness and index of refraction of the lower layer 1406 are varied across substrate 1302. It should be noted that this same approach can be performed in conjunction with or instead of varying the lower layer 1406 to vary the thickness and / or index of refraction of the upper lattice surface 1304 and / or substrate 1302. I want to.

Therefore, various combinations are available, with one index of refraction lower layer 1406 being combined with another index of refraction substrate 1302 and another index of refraction upper lattice 1304 to adjust their relative values. Provides a lot of variation in the dependence of diffraction efficiency on the angle of incidence. Layered waveguides with layers of different indices of refraction are presented. Various combinations and permutations are presented with relevant performance data to illustrate functionality. The advantage is the increase in angle, which provides an increase in output angle using grid 1304 and thus an increase in field of view using eyepieces. Moreover, the ability to counter the usual reduction in diffraction efficiency with angle is functionally beneficial.

FIG. 14B illustrates an embodiment in which another layer (upper surface) of material 1409 is installed above the grid layer 1304. Layer 1409 can be implemented configurable to address different design goals. For example, layer 1409 can form an intervening layer between the plurality of stacked diffraction structures 1401a and 1401b, for example, as shown in FIG. 14C. As shown in FIG. 14C, this intervening layer 1409 can be employed to remove any voids / gaps and provide a support structure for the stacked diffraction components. In this use case, layer 1409 can be formed from a material having a relatively low index of refraction, eg, about 1.1 or 1.2. Although not shown in this figure, other layers (weak lenses, etc.) may also be installed between the diffraction structures 1401a and 1401b.

In addition, layer 1409 can be formed from a material with a relatively high index of refraction. In this situation, it is the grid on layer 1409, not the grid surface 1304, that will provide the diffraction effect on all or a significant amount of incident light.

Obviously, different relative combinations of index values can be selected for different layers, including layer 1409, in order to achieve the desired optical effect and results.

Such structures can be manufactured using any suitable manufacturing technique. High-refractive index polymers, such as those known as "MR174", can be directly embossed, printed, or etched to produce the desired patterned structure, but are associated with curing shrinkage and the like of such layers. There is a challenge to do. Thus, in another embodiment, another material may be transferred, embossed, or etched onto a high refractive index polymer layer (ie, MR174 layer, etc.) to functionally produce similar results. Currently state-of-the-art printing, etching (ie, which may include resist removal and patterning steps similar to those used in conventional semiconductor processes), and embossing techniques are such printing, embossing, and / or It can be utilized and / or combined to perform the etching step. For example, molding techniques similar to those used in the production of DVDs can also be used for certain replication steps. In addition, certain jet jets or deposition techniques used in printing and other deposition processes can also be used to deposit certain layers with precision.

The following part of the present disclosure describes here an improved approach for mounting a forming pattern for diffraction on a substrate, and the imprinting of the implanted transfer material is described in the book. This is done according to some embodiments of the invention. These approaches allow for a very precise distribution of transfer material and a very precise formation of different transfer patterns on any number of substrate surfaces. It should be noted that the following description is used in conjunction with the grid configuration described above and can be used to implement it. However, it should be noted that the deposition approach of the present invention can be used with other configurations as well.

According to some embodiments, a patterned distribution of transfer material (eg, a patterned inkjet distribution) is performed to mount the transfer material deposit on the substrate. This approach, which uses a patterned inkjet distribution, allows for very precise volume control on the material to be deposited. In addition, this approach can serve to provide a smaller, more uniform base layer beneath the grid surface, and as mentioned above, the base thickness of the layer is significant for the performance of the eyepiece / optical device. Can have a significant effect.

FIG. 19 illustrates an approach for implementing precise variable volume deposition of transfer material on a single substrate. As shown in the figure, a template 1902 with a first set of deeper depth structures 1904 and a second set of shallower (eg, standard) depth structures 1906 is provided. When the transfer material is deposited on the transfer receiving side 1908, a relatively larger volume of transfer material 1910 is deposited corresponding to the portion of the template with the deeper depth structure 1904 of the template 1902. In contrast, a relatively smaller volume of transfer material 1912 is deposited corresponding to the shallower depth structure 1906 of template 1902. The template is then used to transfer a set of first and second depth structures into the transfer material to form the respective structures with different depths and / or patterns within the transfer material. This approach therefore allows for the simultaneous formation of different features on the transcription recipient 1908.

This approach can be utilized to generate a distribution that is intentionally non-uniform for structures with different depths and / or feature parameters, for example, the feature structures are on the same substrate and are different. Has a thickness. It can be used, for example, to generate a spatially distributed volume of transfer material that allows simultaneous transfer of variable depth structures with the same underlayer thickness.

The bottom of FIG. 19 illustrates the structure 1920 formed using the deposition technique / equipment described above, and the lower layer 1922 has a uniform thickness regardless of differences in pattern depth and volume. It can be seen that the transfer material is deposited in the structure 1920 with a non-uniform thickness. Here, the upper layer 1924 includes a first portion 1926 having a first set of layer thicknesses, while a second portion 1928 has a second set of layer thicknesses. In this example, portion 1926 corresponds to a thicker layer compared to the standard / shallower thickness of portion 1928. However, any combination of thicknesses can be constructed using the concepts of the invention so that thicknesses that are either thicker and / or thinner than standard thicknesses / both are formed on the underlayer. Please note.

This ability can be used, for example, to deposit a larger volume of material to serve as a spacer element and, for example, to assist in the construction of a multilayer diffractive optical element.

Some embodiments relate to approaches for implementing simultaneous deposition of multiple types of transfer material on a substrate. This allows materials with optical properties to be deposited simultaneously over multiple parts of the substrate at one time. This approach is also for adjusting the local area associated with a specific function (eg, acting as an internally coupled lattice, an orthogonal pupil magnifying element (OPE) lattice, or an exit pupil expanding element (EPE) lattice). Provide the ability.

FIG. 20 illustrates approaches and transfer steps for implementing directional co-deposition of a plurality of different transfer materials within the same layer, according to some embodiments. As shown in the figure, the template 2002 is provided for transferring the pattern into different types of transfer materials 2010 and 2012 on the transfer recipient 2008. Materials 2010 and 2012 may include the same material with different optical properties (eg, two variants of the same material with different refractive indexes) or two completely different materials.

Any optical properties of the material can be considered and selected when adopting this technique. For example, as shown in the embodiment of FIG. 20, the material 2010 corresponds to a high refractive index material deposited within a section of the transfer receiving side 2008, while at the same time the material 2012 is an area of the second section. Corresponds to lower index material deposited within.

As shown in the resulting structure 2020, this forms a multifunctional diffractive optical element with a high index of refraction portion 2026 and a lower index of refraction portion 2028. In this case, the high refractive index portion 2026 for the first function and the portion 2028 for the second function were simultaneously transcribed.

This example exemplifies the index of refraction of a material as an optical property that should be "adjusted" when depositing the material simultaneously, but other optical properties are also the type of material for depositing within different parts of the structure. Note that it can be considered when identifying. For example, opacity and absorbance are other properties that can be used to identify materials for deposition within different parts of the structure and to adjust the local properties of the final product.

In addition, one type of material can be deposited above / below another material prior to transfer. For example, one index of refraction material may be deposited directly beneath a second rate of refraction material just prior to transfer to generate a refractive index gradient for forming diffractive optics. It can be used, for example, to implement the structure shown in FIG. 17A (or either of the aforementioned or other related structures in the figure).

According to another embodiment, multi-sided transfer can be employed to transfer to multiple sides of the optical structure. This allows transfer to occur on different sides of the optics and implement functional multiplexing through the base layer volume. In this method, different eyepiece functions can be implemented without adversely affecting the lattice structure function.

21A-B illustrate an exemplary approach for implementing two-sided transfer in the context of total internal reflection diffractive optics. As illustrated in FIG. 21A, the first template 2102a can be used to generate a transfer on the side surface "A" of the substrate / transfer receiving side 2108. This forms a first pattern 2112 with the first material on the side surface A of the structure.

As illustrated in FIG. 21B, template 2102b can be used to generate a second transfer on the side surface "B" of the same substrate. This forms a second pattern 2114 with the second material on the side surface B of the substrate.

Note that sides A and B can have the same or different patterns and / or have the same or different types of material. In addition, the pattern on each side can have different layer thicknesses (eg, using the approach of FIG. 19) and / or have different material types on the same side (eg, of FIG. 20). Using an approach).

As shown in FIG. 22, the first pattern 2112 is transferred onto the side surface A of the substrate 2108, and the second pattern 2114 is transferred onto the opposite side surface B. The resulting combined function of the two-sided transcribed element 2200 can be realized here. In particular, when incident light is applied to the two-sided transferred element 2200, some light is emitted from the element 2200 to implement the first function 1, while other light is emitted and the second. Implement function 2 of 2.

Additional embodiments relate to multilayer multiple transfer and / or multilayer separation / offset substrate integration. With either or both of these approaches, previously transcribed patterns can be ejected and printed again. The adhesive can be ejected onto the first layer, the second substrate is joined to it (possibly with voids), and the subsequent ejection process deposits and transfers on the second substrate. Can be done. A series of transferred patterns can be sequentially joined together in a roll-to-roll process. Note that the approach of implementing multi-layer multiple transfer can be used with or instead of the multi-layer separation / offset substrate integration approach.

FIG. 23 illustrates an approach for implementing multilayer multiple transfer. Here, the first transfer material 2301 can be deposited and transferred on the substrate 2308. This is followed by the deposition (and possible transfer) of the second transfer material 2302. This results in a composite multilayer structure having both the first transfer material 2301 and the second transfer material 2302. In one embodiment, subsequent transfer may be implemented for the second transfer material 2302. In an alternative embodiment, subsequent transfer is not implemented for the second transfer material 2302.

FIG. 24 illustrates an approach for implementing multi-layer separation / offset substrate integration. Here, both the first substrate 1 and the second substrate 2 can be deposited with the transfer material and then transferred. Substrate 1 and substrate 2 can then be sandwiched and joined, and in one embodiment, an offset feature (similarly transferred) that provides a gap 2402 between the active structure of substrate 2 and the backside of substrate 1. ) Is accompanied. The transferred spacer 2404 can be used to create voids 2402.

Yet another embodiment discloses an approach for implementing variable volume deposition of materials distributed across substrates, which may rely on a priori knowledge of surface heterogeneity. For illustration purposes, the substrate 2502 shown in FIG. 25 will be considered. As shown, the surface non-uniformity of the substrate 2502 can result in undesired parallelism and poor optical performance. In this case, substrate 2502 (or previously transferred layer) can be measured for variability.

Variable volume deposition of transfer material can be employed to provide a horizontal distribution of transfer material to be deposited, independent of underlying topography or physical feature sets. For example, the substrate is pulled flat by a vacuum chuck and in-situ measurements can be made to assess surface height, for example using a low coherence or laser-based contact measurement probe. The distributed volume of the transfer material can be varied depending on the measured data to provide a more uniform layer during reproduction. In this example, portion 2504a of the substrate has the highest level of variability, portion 2504b has intermediate levels of variability, and portion 2504c has the lowest level of variability. Thus, a large volume transfer material can be deposited in the portion 2504a, a medium volume transfer material is deposited in the portion 2504b, and a small / standard volume transfer material is deposited in the portion 2504c. Be done. As indicated by the resulting product 2506, this results in a more uniform total substrate / transfer material / transfer pattern thickness, which in turn can adjust or benefit the performance of the transferred device.

Although the examples show variations due to thickness non-uniformity, it should be noted that other types of non-uniformity can also be addressed by this embodiment of the invention. In another embodiment, such variability may be due to depressions, peaks, or other anomalies, or the presence of features associated with local location on the substrate.

In the above specification, the present invention has been described with reference to specific embodiments thereof. However, it will be clear that various modifications and changes can be made there without departing from the broader spirit and scope of the invention. For example, the process flow described above is described with reference to a particular order of process actions. However, the order of many of the process actions described can be modified without affecting the scope or behavior of the invention. The specification and drawings are therefore considered to be in an exemplary sense rather than a restrictive sense.

Various exemplary embodiments of the invention are described herein. In a non-limiting sense, these examples are referred to. They are provided to illustrate the broader and bulletinable aspects of the invention. Various modifications can be made to the invention described and equivalents can be replaced without departing from the true spirit and scope of the invention. In addition, many modifications can be made to adapt a particular situation, material, material composition, process, process action, or step to the object, spirit, or scope of the invention. Moreover, as will be appreciated by those skilled in the art, each of the individual variants described and illustrated herein will be of some other embodiment without departing from the scope or spirit of the invention. It has discrete components and features that can be easily separated from or combined with any of the features. All such amendments are intended to be within the claims associated with this disclosure.

The present invention includes methods that can be performed using the device of interest. The method may include the act of providing such a suitable device. Such provision may be made by the end user. In other words, the act of "providing" simply acquires, accesses, approaches, positions, configures, boots, powers on, and provides the end user with the essential device in the target method. Or require it to act differently. The methods described herein can be performed in any order of the described events that are logically possible, as well as in the order in which the events are described.

Illustrative aspects of the invention are described above, along with details regarding material selection and manufacture. With respect to other details of the invention, they will be understood in connection with the patents and publications referenced above, and will generally be known or understood by those skilled in the art. The same may be true with respect to the method-based aspects of the invention in terms of additional actions that are generally or logically adopted.

In addition, while the invention has been described with reference to some embodiments that optionally incorporate various features, the invention is described and directed as considered for each variant of the invention. It is not limited to things. Various modifications can be made to the invention described and are included for some simplification, as described herein, without departing from the true spirit and scope of the invention. Can be replaced. In addition, if a range of values is provided, all intervening values between the upper and lower bounds of the range, and any other provisions or intervening values within that defined range, are included within the invention. Please understand that.

Any optional feature of the embodiments of the invention described may be described and claimed independently or in combination with any one or more of the features described herein. Is also assumed. References to singular items include the possibility that the same plural item exists. More specifically, as used herein and in the claims associated with this specification, "one (" a "," an ")", "said", and " The singular form "the (the)" includes the plural referent unless otherwise specified. In other words, the use of articles allows for "at least one" of the subject item in the above description as well as in the claims associated with the present disclosure. Moreover, it should be noted that such claims may be drafted to exclude any voluntary elements. Therefore, this statement serves as an antecedent for the use of exclusive terms such as "simply", "only", or the use of "negative" restrictions in connection with the description of the elements of the claim. The purpose is to fulfill.

Without using such exclusive terms, the term "equipped" in the claims associated with this disclosure is such that a given number of elements are listed or featured in such claims. It shall be possible to include any additional elements, regardless of whether the addition of may be considered as a transformation of the nature of the elements described in such claims. Except as specifically defined herein, all technical and scientific terms used herein are generally understood as broadly as possible while maintaining the validity of the claims. It is given the meaning of being.

The scope of the present invention is not limited to the specification provided in the examples and / or the subject matter, but rather is limited only by the scope of the claims associated with the present disclosure.

The above description of the illustrated embodiments is not intended to be exclusive or to limit the embodiments to the disclosed precise embodiments. Specific embodiments and examples are described herein for illustrative purposes, but various equivalent modifications deviate from the spirit and scope of the present disclosure, as will be appreciated by those skilled in the art. Can be done without doing. The teachings provided herein in various embodiments are not necessarily exemplary AR systems generally described above, but implement virtual or AR or hybrid systems and / or employ user interfaces, etc. Can also be applied to devices in.

For example, the detailed description described above describes various embodiments of the device and / or process through the use of block diagrams, schematics, and examples. As long as such block diagrams, schematics, and embodiments contain one or more functions and / or behaviors, each function and / or behavior within such block diagrams, flow diagrams, or embodiments will It will be appreciated by those skilled in the art that it can be implemented individually and / or collectively by a wide range of hardware, software, firmware, or virtually any combination thereof.

In one embodiment, the subject may be implemented via an application specific integrated circuit (ASIC). However, those skilled in the art will appreciate that the embodiments disclosed herein, in whole or in part, as one or more computer programs executed by one or more computers (eg, on one or more computer systems). One executed by one or more processors (eg, microprocessor) as one or more programs executed by one or more controllers (eg, a microprocessor) (as one or more programs launched by) The above programs, as firmware, or virtually any combination thereof, can be equally implemented in a standard integrated circuit, designing the circuit for software and / or firmware and / or writing code. It will be recognized that the program will be well within the skill of those skilled in the art in the light of the teachings of this disclosure.

When logic is implemented as software and stored in memory, the logic or information is stored on any computer-readable medium for use by or in connection with any processor-related system or method. Can be done. In the context of the present disclosure, memory is a computer-readable medium that is an electronic, magnetic, optical, or other physical device or means that contains or stores a computer and / or processor program. Logical and / or information can fetch instructions from an instruction execution system, device, or device and execute instructions associated with the logic and / or information, computer-based systems, processor-containing systems, or other. It can be embodied in any computer readable medium for use by or in connection with an instruction execution system, device, or device such as a system.

In the context of this specification, "computer-readable medium" stores programs associated with logic and / or information for use by or in connection with instruction execution systems, devices, and / or devices. Get, can be any element. Computer-readable media can be, for example, but not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or devices. More specific examples (non-comprehensive lists) of computer-readable media include portable computer deckets (magnetic, compact flash® cards, secure digital, or equivalents), random access memory (RAM), and read. Dedicated memory (ROM), erasable programmable read-only memory (EPROM, EEPROM, or flash memory), portable compact disk read-only memory (CDROM), digital tape, and other non-transient media may be mentioned.

Many of the methods described herein can be performed with variations. For example, many of the methods may omit some actions, including additional actions, and / or be performed in a different order than that illustrated or described.

Further embodiments can be provided by combining the various embodiments described above. All US patents, US patent application publications, US patent applications, foreign patents, foreign patent applications and non-patent publications mentioned herein and / or listed in the application datasheet are the specific teachings of this specification. And, as long as they are consistent with the definitions, they are incorporated herein by reference in their entirety. The embodiments may be modified if it is necessary to utilize the systems, circuits, and concepts of various patents, applications, and publications to still provide further embodiments. ..

These and other modifications can be made in embodiments in the light of the description detailed above. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed herein and in the claims, but such claims. It should be construed to include all possible embodiments, as well as the entire scope of the equality to which. Therefore, the claims are not limited by this disclosure.

In addition, the various embodiments described above can be combined to provide additional embodiments. Moreover, aspects of the embodiment may be modified, if desired, to adopt the concepts of various patents, applications, and publications to provide further embodiments.

These and other modifications can be made in embodiments in the light of the description detailed above. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed herein and in the claims, but such claims. It should be construed to include all possible embodiments, as well as the entire scope of the equality to which. Therefore, the claims are not limited by this disclosure.

Claims (16)

A method of manufacturing an eyepiece including a first diffractive optical element, wherein the method is
By depositing a first layer on a first substrate, the first layer includes a first portion and a second portion, and the first portion is the first substrate. The first portion is deposited to have a first depth on the first region above, the first portion has the first optical properties, and the second portion is the first on the first substrate. It is deposited on the region 2 so as to have a second depth, and the second portion has a second optical characteristic different from the first optical characteristic.
To identify a template, the template has a transfer pattern formed on it, the template comprising a first set of depth structures and a second set of depth structures, said first. The set of depth structures of 1 corresponds to the first depth of the first portion, and the set of second depth structures corresponds to the second depth of the second portion. ,
The template is used to include transferring the transfer pattern into the first portion and the second portion on the first substrate.
The method, wherein the transfer pattern includes a diffraction pattern for the first diffractive optical element, the first depth being different from the second depth. The method is described by simultaneously transferring into the first portion and the second portion deposited on the first region and the second region, respectively, using at least the template. It further comprises forming a first pattern and a second pattern on the first substrate.
The transfer pattern includes the first pattern and the second pattern.
The template is used to transfer the first pattern with the first set of depth structures onto the first portion.
The method of claim 1, wherein the template is used to transfer the second pattern with the second set of depth structures onto the second portion. The method according to claim 2, wherein the first pattern corresponds to a first diffraction grating pattern, and the second pattern corresponds to a second diffraction grating pattern. The first portion is deposited to have the first depth due to at least the first optical function, and the second portion is deposited to have the second depth due to at least the second optical function. The method according to claim 2, wherein the first optical function or the second optical function includes a function of an internally coupled lattice, a function of an orthogonal pupil magnifying element lattice, or a function of an exit pupil expanding element lattice. .. The method uses the template to transfer the transfer pattern into the first portion and the second portion on the first substrate and then to the first diffractive optical element of the eyepiece. In contrast, it further comprises depositing a second layer above the first layer.
The second layer comprises a first material having a first refractive index value within the first region of the second layer.
The second layer further comprises a second material having a second index of refraction within the second region of the second layer.
The first substrate contains a third material having a third refractive index value.
The first refractive index value, the second refractive index value, and the third refractive index value are the first requirement for diffraction efficiency or the field of view provided by the first diffractive optical element of the eyepiece. The method of claim 1, which is selected based on at least the second requirement for. The method further comprises stacking a second diffractive optical element above the first lens, which is further stacked above the first diffractive optical element, with respect to the eyepiece.
The first diffractive optical element defines a first focal length that is closer to the viewer's eye than the second diffractive optical element and has a first focal length at optical infinity.
The second diffractive optical element comprises a second substrate and defines a second focal length with a second focal length smaller than the first focal length at optical infinity.
The method of claim 1, wherein the second diffractive optical element is separated from the first diffractive optical element by a first negative lens. The method further comprises stacking a third diffractive optical element above the second diffractive optical element with respect to the eyepiece.
The third diffractive optical element includes a third substrate and is arranged further away from the viewer's eye than the second diffractive optical element.
The third diffractive optical element defines a third focal length with a third focal length that is smaller than the second focal length.
The method according to claim 6, wherein the third diffractive optical element is separated from the second diffractive optical element by a second lens. The method is
Transferring the first pattern into the first part,
Further including transcribing a second pattern different from the first pattern into the second portion.
The method according to claim 1, wherein the transfer pattern includes the first pattern and the second pattern. The method further comprises depositing a compensating lens layer above the third diffractive optical element with respect to the eyepiece, wherein the compensating lens layer is of the first lens and the second lens. The method of claim 7, wherein the method is selected based on at least the total refractive power. The method of claim 7, wherein the first lens and the second lens create wavefront divergence that defines different focal planes with different focal lengths that are smaller than the third focal length. The method further comprises stacking one or more additional diffractive optics on the eyepiece, above the third diffractive optics and away from the viewer's eyes. The three diffractive optics are separated from the one or more additional diffractive optics by a separating lens, and the one or more additional diffractive optics correspond to one or more smaller than the third focal distance. The method of claim 7, wherein each focal plane with a focal distance is defined. The method further comprises placing a compensating lens layer above the one or more additional diffractive optics, wherein the compensating lens layer is the total refractive power of the lens that separates the diffractive optics in the eyepiece. 11. The method of claim 11, which is selected based on at least. The method of claim 1, wherein the first substrate having the first transferred pattern is superposed on a second substrate having the second transferred pattern. By multiplexing at least two of the first diffractive optical element, the second diffractive optical element, and the third diffractive optical element, the first focal plane and the second focal plane and the second focal plane and the like are The method of claim 7, wherein at least one additional focal plane is created in addition to the third focal plane. The method further comprises depositing a second layer on the first substrate with respect to the first diffractive optical element of the eyepiece.
The second layer is deposited on the opposite surface facing the surface on which the first layer is deposited.
The second layer comprises a first material having a first index of refraction value within the first region of the second layer.
The first substrate contains a second material different from the first material, which has a second refractive index value different from the first refractive index value.
The first refractive index value and the second refractive index value are at least a first requirement for diffraction efficiency or a second requirement for the field of view provided by the first diffractive optical element of the eyepiece. The method according to claim 1. 6. The first diffractive optical element corresponds to a first set of one or more projectors, and the second diffractive optical element corresponds to a second set of one or more projectors. The method described.

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