Method for producing light guide optical element

Abstract

A method for manufacturing a light guide optical element (LOE) is provided. The method involves obtaining a first optical structure and a second optical structure, each optical structure having a set of mutually parallel partially reflective surfaces. The structures are joined together such that their reflective surfaces are non-parallel, thereby forming a third optical structure. At least one of the first optical structure or the second optical structure is cut along a particular line before or after bonding, and the third optical structure is sliced along parallel planes to create one or more LOEs. Each LOE depicts features of parallel major outer surfaces and regions having mutually parallel partially reflective surfaces from two original groups. Specific lines may include contour segments and / or typical straight line segments. The contoured segment defines a contoured distribution of the LOE, and the generally straight segment defines an in-coupling surface of the LOE.

Description

Cross-reference to related applications

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 605,523, filed December 3, 2023; U.S. Provisional Patent Application No. 63 / 621,608, filed January 17, 2024; and U.S. Provisional Patent Application No. 63 / 671,419, filed July 15, 2024, the disclosures of all of which are incorporated herein by reference in their entirety. Technical Field

[0002] This disclosure relates to optical systems, and more particularly to methods for manufacturing light-guide optical elements (LOEs) that achieve optical aperture expansion. Background Technology

[0003] Various types of displays (such as near-eye displays) require large apertures to cover the area where the observer's (i.e., the user's, viewer's) eyes are located (often referred to as an eye-motion box (EMB) or EMB). To achieve a compact device, the image to be projected onto the observer's eyes is generated by a small optical image generator (projector) with a small optical aperture. The optical arrangement for the display can employ light-guiding optical elements (LOEs) to extend the input image in one or more dimensions. Where two-dimensional extension is required, an LOE with two extension regions can be used, one region configured to extend the image in one dimension and the other region configured to extend the image in another dimension. Particularly relevant to this disclosure is a reflective LOE, wherein the LOE is implemented as a transparent block defined by two parallel primary outer surfaces configured to support light propagation therebetween via (total) internal reflection, and wherein image extension in each region is performed by a set of mutually parallel partially reflective inner surfaces (or "facets") located between the primary outer surfaces. The collimated image propagating within the LOE is gradually partially deflected by the set of facets in the first region toward the set of facets in the second region, and further gradually partially deflected by the set of facets in the second region toward the observer's eye, thereby presenting the image to the observer. Summary of the Invention

[0004] This disclosure provides a method for manufacturing optical light guide elements (LOEs).

[0005] According to the teachings of embodiments of this disclosure, a method for manufacturing one or more light-guide optical elements (LOEs) is provided. The method includes: obtaining a first optical structure having a first set of mutually parallel partially reflective surfaces; obtaining a second optical structure having a second set of mutually parallel partially reflective surfaces; joining the first and second optical structures together such that the first set of partially reflective surfaces is not parallel to the second set of partially reflective surfaces to form a third optical structure; cutting at least one of the first or second optical structures along a contour line; and slicing the third optical structure along at least two parallel cutting planes to form one or more LOEs, each of the one or more LOEs being contoured according to the contour line such that all LOEs have the same contour shape.

[0006] Optionally, before joining the first and second optical structures together, the contour segments along the contour line are cut.

[0007] Alternatively, cutting along the contour line can be performed by cutting the third optical structure.

[0008] Optionally, the profile includes a segment that intersects a portion of the first optical structure to define a boundary surface at the first optical structure, the boundary surface defining the coupling surface of each of one or more LOEs.

[0009] Optionally, the method further includes polishing the boundary surface.

[0010] Optionally, the segment is a substantially straight line segment, such that the boundary surface defined by the second part is a boundary plane.

[0011] Optionally, the method further includes: for each of one or more LOEs, bonding the coupling optics to the coupling surface.

[0012] Optionally, the method further includes attaching a blank at a boundary surface before slicing the third optical structure, such that each of one or more LOEs has a portion of the blank located at the coupling surface.

[0013] Optionally, the method further includes: polishing a pair of parallel main outer surfaces for each of one or more LOEs; and removing a portion of the blank located at the coupling surface.

[0014] Optionally, the method further includes: for each of one or more LOEs, optically coupling an image projector to the LOE associated with the coupled surface.

[0015] Optionally, for each of one or more LOEs, the coupling surface is a planar surface obliquely inclined relative to a pair of parallel main outer surfaces, and the method further includes: for each of one or more LOEs, optically coupling an image projector to the LOE, coupling between the interface of the image projector and the planar surface, the interface being obliquely inclined relative to a pair of parallel main outer surfaces.

[0016] Optionally, the first optical structure includes a reference surface, and at least two parallel cutting planes are perpendicular to the reference surface.

[0017] Optionally, the third optical structure includes an intermediate optical structure between the first optical structure and the second optical structure.

[0018] Optionally, the intermediate optical structure is optically inert.

[0019] Optionally, the intermediate optical structure includes one or more filters or polarization management elements.

[0020] Optionally, the intermediate optical structure has at least one partially reflective surface located between the first set of partially reflective surfaces and the second set of partially reflective surfaces and parallel to at least two cutting planes.

[0021] Optionally, the first optical structure is formed by an alternating stack of parallel face plates joined together at multiple interfaces, with one face at each interface having a coating to provide partial reflective optical properties, such that the interfaces form a first set of partially reflective surfaces that are parallel to each other.

[0022] Optionally, obtaining the first optical structure includes: joining a plurality of parallel faces together at a plurality of interfaces to form a stack of plates, having a coating on one face at each interface to provide partially reflective optical properties, and cutting the stack along a pair of cutting planes intersecting at least some of the plurality of interfaces.

[0023] Optionally, joining multiple parallel-faced panels together includes: at each interface, providing an adhesive between the coating and another face at the interface, wherein for each interface, the boundary surface is closer to the face with the coating than to the adhesive.

[0024] Optionally, the second optical structure is formed as an interleaved stack of parallel-faced plates joined together at multiple interfaces, with one face at each interface having a coating to provide partial reflective optical properties, such that the interfaces form a second set of mutually parallel partial reflective surfaces.

[0025] Optionally, obtaining the second optical structure includes: joining a plurality of parallel faces together at a plurality of interfaces to form a stack of plates, having a coating on one face at each interface to provide partially reflective optical properties, and cutting the stack along a pair of cutting planes intersecting at least some of the plurality of interfaces.

[0026] Optionally, joining multiple parallel-faced plates together includes: at each interface, providing an adhesive between the coating and another face at the interface, wherein for each interface, the first optical structure is closer to the face with the coating than to the adhesive.

[0027] Based on the teachings of embodiments of this disclosure, a method for manufacturing one or more light-guide optical elements (LOEs) is also provided. The method includes: obtaining a first optical structure and a second optical structure, the first optical structure having a first set of mutually parallel partially reflective surfaces, and the second optical structure having a second set of mutually parallel partially reflective surfaces; joining the first and second optical structures together such that the first set of partially reflective surfaces is not parallel to the second set of partially reflective surfaces to form a third optical structure; cutting the first and second optical structures along a contour line; slicing the third optical structure along at least two parallel cutting planes to form one or more LOEs, each of the one or more LOEs being contoured according to the contour line such that all LOEs have the same contour shape; and cutting each of the one or more LOEs along a substantially straight cutting line intersecting a portion of a first region to define a coupling surface of the LOE.

[0028] Alternatively, cutting each of one or more LOEs along a substantially straight cutting line is performed using a single cutting pair of multiple LOEs held together.

[0029] Optionally, the method further includes: for each of one or more LOEs, bonding the coupling optics to the coupling surface.

[0030] According to the teachings of embodiments of this disclosure, a method for manufacturing one or more light-guide optical elements (LOEs) is also provided. The method includes: obtaining a first optical structure having a first set of mutually parallel partially reflective surfaces; obtaining a second optical structure having a second set of mutually parallel partially reflective surfaces; joining the first and second optical structures together such that the first set of partially reflective surfaces is not parallel to the second set of partially reflective surfaces to form a third optical structure; cutting along a dicing line including a segment intersecting a portion of the first optical structure to define a boundary surface at the first optical structure; attaching a blank at the boundary surface; and slicing the third optical structure along at least two parallel dicing planes to form one or more LOEs, each of the one or more LOEs having an insertion surface defined by the boundary surface and having a portion of the blank located at the insertion surface.

[0031] Unless otherwise defined herein, all technical and / or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. While similar or equivalent methods and materials may be used in practicing or testing embodiments of the invention, exemplary methods and / or materials are described below. In case of conflict, the patent specification, including its definitions, shall prevail. Furthermore, materials, methods, and examples are illustrative only and are not intended to be necessarily limiting. Attached Figure Description

[0032] Some embodiments of this disclosure are described herein by way of example only with reference to the accompanying drawings. Detailed reference is made to the drawings, and it is emphasized that the details shown are by way of example and for the purpose of illustrative discussion of embodiments of this disclosure. In this respect, the description taken in conjunction with the drawings makes it apparent to those skilled in the art how embodiments of this disclosure can be practiced.

[0033] Now focus on the accompanying drawings, in which the same reference numerals or characters indicate corresponding or identical parts. In the accompanying drawings:

[0034] Figure 1A and 1B The diagram is a schematic isometric view of an optical system constructed and operated in accordance with the teachings of this disclosure, using a light-guide optical element (LOE), showing a top-down configuration and a side-injection configuration, respectively.

[0035] Figure 2A and 2B It comes from Figure 1A Or a magnified schematic isometric view of the LOE of 1B, showing the ray paths of the two extreme fields of the image;

[0036] Figure 3This is a schematic representation of the stages of a method for manufacturing one or more LOEs according to an embodiment of the present disclosure, including the stages of slicing a combined stack of two bonding plates and then contouring each slice.

[0037] Figure 4 This is a schematic representation of a stage of a modified method for manufacturing one or more LOEs according to an embodiment of the present disclosure, including a stage of cutting a combined stack of two bonding plates to generate a boundary plane forming an coupling surface.

[0038] Figure 5 This is an illustrative representation of additional stages in a method for manufacturing one or more LOEs according to embodiments of the present disclosure, including stages of polishing the main outer surface of the LOE and optically coupling an image projection optics to the coupling surface of the LOE.

[0039] Figure 6 This is a schematic representation of the stages of a modified method for manufacturing one or more LOEs according to embodiments of the present disclosure, including the stages of temporarily attaching blanks at a boundary plane, outlining the composite stack, and cutting one or more LOEs from the composite stack.

[0040] Figure 7 From Figure 6 A schematic isometric representation of the LOEs cut out from the combination of stacked elements;

[0041] Figure 8 This is an implementation method based on the content of this disclosure. Figure 6 The schematic representation of additional stages of the method includes stages of polishing the main outer surface of the LOE, removing the blank, and optically coupling the image projection optics to the coupling surface of the LOE.

[0042] Figure 9 Through Figure 8 A schematic isometric representation of the LOE generated by the method;

[0043] Figure 10 This is a schematic representation of the stages of a modified method for manufacturing one or more LOEs according to an embodiment of the present disclosure, including the stages of outlining a combined stack of two bonding plates, cutting out one or more outlining LOEs from the outlining combined stack, and cutting each LOE to generate a boundary plane forming an coupling surface.

[0044] Figure 11 This is a schematic representation of a stage in a method for extracting sub-stacks of joint plates from a stack of joint plates;

[0045] Figure 12A and 12BThese are different schematic isometric views of the first staggered stack of joining plates that can be used in a method for manufacturing one or more LOEs according to embodiments of this disclosure;

[0046] Figure 13A and 13B These are different schematic isometric views of a second staggered stack of bonding plates that can be used in a method for manufacturing one or more LOEs according to embodiments of this disclosure;

[0047] Figure 14 This is an illustrative representation of stages in a method for manufacturing one or more LOEs according to embodiments of this disclosure, including from Figure 12A and Figure 12B Sub-stacks of the staggered stacked extraction plate, from Figure 13A and Figure 13B The sub-stacks and second interleaved stacks form a combined stack, and the combined stack is outlined and sliced ​​to extract one or more LOEs;

[0048] Figures 15A to 15C Through Figure 14 Different schematic isometric views of the LOE generated by the method;

[0049] Figure 16 This is an implementation method based on the content of this disclosure. Figure 14 A schematic representation of an additional stage of the method, including the stage of optically coupling an image projector with a LOE;

[0050] Figure 17 This is a schematic representation of the stages of a conventional method for manufacturing one-dimensional LOEs, including the stages of stacking and bonding plates coated with a partially reflective coating.

[0051] Figure 18 yes Figure 17 A schematic representation of a single plate, showing a partially reflective coating on a small plane of a plate;

[0052] Figure 19 Is using Figure 17 A schematic representation of the LOE generated by the method, showing light propagating through the LOE;

[0053] Figure 20A and 20B This is an implementation method based on the content of this disclosure. Figure 17 A schematic representation of two plates, showing an enlarged view of the interface between two plates with different orders of coatings and adhesives;

[0054] Figure 21A and Figure 21B The embodiments according to this disclosure correspond to respectively Figure 20A and Figure 20B The schematic representation shows light propagating through the plate and interacting with the coating and adhesive at the interface;

[0055] Figure 22 This is a schematic representation of the stages of a method for manufacturing a one-dimensional LOE according to embodiments of the present disclosure, including stages of coating multiple plates entirely on the same side of the plate and applying adhesive to opposite sides of the plate; and

[0056] Figure 23 This is a use of the implementation of the content of this disclosure. Figure 17 A schematic representation of the LOE produced by the method is shown, illustrating illumination of the LOE from the illumination direction, such that the illumination first illuminates the coating rather than the adhesive. Detailed Implementation

[0057] Implementations of this disclosure provide a method for manufacturing a LOE.

[0058] The principles of the method according to this disclosure can be better understood by referring to the accompanying drawings.

[0059] Before explaining at least one embodiment of this disclosure in detail, it should be understood that this disclosure is not necessarily limited in its application to the details of the construction and arrangement of components and / or methods set forth in the following description and / or shown in the drawings and / or examples. Embodiments of this disclosure can be other embodiments or can be practiced or performed in various ways. For example, initially in this document, references are made to directions such as left and right, top and bottom, up and down, front and back, etc. These directional references are merely exemplary and are only used for ease of presentation and to refer to any orientation as shown in the drawings. The final optical device can be deployed in any desired orientation.

[0060] Some embodiments of this disclosure provide a method for manufacturing a light guide optical element (LOE) for achieving optical aperture expansion for use in a head-up display, and most preferably for a near-eye display, or more preferably for an augmented reality display, which may be a virtual reality display. Although the manufacturing method is not limited to such applications, Figures 1 to... Figure 3 Examples of particularly preferred optical arrangements and corresponding devices are shown that are particularly relevant to the manufacturing method of this disclosure.

[0061] Figure 1A and Figure 1BAn exemplary implementation of a near-eye display (generally designated 200) employing an LOE 212, as taught by embodiments of this disclosure, is schematically illustrated. The near-eye display 200 employs a compact image projector (or "POD" (Projecting Optical Device)) 214 optically coupled to the LOE to provide an image to be injected into the LOE (interchangeably referred to as a "waveguide," "substrate," or "plate") 212, within which image light is captured by internal reflection at a set of mutually parallel planar outer surfaces. Light is irradiated by a set of partially reflective surfaces (interchangeably referred to as "planes") parallel to each other and obliquely inclined to the direction of image light propagation, wherein each successive plane deflects a portion of the image light in the deflection direction, and a portion of the image light is also captured / guided by internal reflection within the substrate. This first set of planes is not in… Figure 1A and Figure 1B Instead of being shown separately, it is located in the first region of the LOE (specified as 216). This partial reflection at the continuous facets achieves the optical aperture extension in the first dimension.

[0062] In a first set of preferred but non-limiting examples of the invention, the aforementioned set of facets is orthogonal to the main outer surface of the substrate. In this case, both the injected image and its conjugate, which undergoes internal reflection as it propagates within region 216, are deflected and become a conjugate image propagating in the deflection direction. In an alternative set of preferred but non-limiting examples, the first set of partially reflective surfaces is angled relative to the main outer surface of the LOE. In the latter case, the injected image or its conjugate forms the desired deflected image propagating within the LOE, while other reflections can be minimized, for example, by employing an angle-selective coating on the facets, which makes the facets relatively transparent to the range of incident angles from which images that do not require their reflection are presented.

[0063] The first set of partially reflective surfaces deflects the image illumination from a first propagation direction captured within the substrate by total internal reflection (TIR) ​​to a second propagation direction also captured within the substrate by TIR.

[0064] The deflected image illumination then enters a second region (designated 218) of the LOE, which can be implemented as adjacent different substrates or as a continuation of a single substrate, wherein a coupling arrangement (implemented as another set of partially reflective facets) progressively couples a portion of the image illumination toward the observer's eye located within the area defined as the eye-tracking box (EMB), thereby achieving a second-dimensional optical aperture expansion. The entire device can be implemented separately for each eye, and preferably, the entire device is supported relative to the user's head, with each LOE 212 facing the user's corresponding eye. In a particularly preferred option as shown here, the support arrangement is implemented as an eyeglass frame with sides 220 for supporting the device relative to the user's ears. Other forms of support arrangements may also be used, including but not limited to headbands, face shields, or devices suspended from a helmet.

[0065] In this text and the accompanying figures, with reference to the X-axis (dimension) and Y-axis (dimension), the X-axis (dimension) is horizontal in the approximate extension direction of the first LOE region 216. Figure 1A ) or vertically ( Figure 1B Extending, the Y-axis (dimension) extends perpendicularly to the X-axis, that is, in Figure 1A Extending vertically in the middle and in Figure 1B Extending horizontally.

[0066] In very approximate terms, the first LOE region 216 (which may be interchangeably referred to as the first LOE or the first region of LOE) can be considered to achieve aperture expansion in the X dimension (in the direction indicated by the X arrow in the figures), while the second LOE region 218 (which may be interchangeably referred to as the second LOE or the second region of LOE) achieves aperture expansion in the Y dimension (in the direction indicated by the Y arrow in the figures). It should be noted that, as Figure 1A The orientation shown can be considered a "top-down" implementation, in which image illumination entering the main region (second region) of the LOE enters from the top edge, while... Figure 1B The orientation shown can be considered a "lateral injection" implementation, in which the axis referred to here as the Y-axis is deployed horizontally. In the remaining figures, similar to... Figure 1A Various features of certain embodiments of the invention are illustrated in the context of a "top-down" orientation. However, it should be understood that all these features are equally applicable to lateral injection implementations that also fall within the scope of the invention. In some cases, other intermediate orientations are also applicable and, unless explicitly excluded, are included within the scope of the invention.

[0067] The image projector 214 used with the apparatus of this disclosure is preferably configured to generate a collimated image, in which the light for each image pixel is a collimated parallel beam having an angular direction corresponding to the pixel position extending to infinity. Therefore, the image illumination spans an angular range corresponding to a two-dimensional angular field of view.

[0068] Image projector 214 includes at least one light source, which is typically deployed to illuminate a spatial light modulator such as an LCOS chip. The spatial light modulator modulates the projection intensity of each pixel of the image, thereby generating the image. Alternatively, the image projector may include a scanning arrangement typically implemented using fast scanning mirrors, which scans the illumination from the laser light source across the image plane of the projector while the intensity of the beam varies in sync with the motion on a pixel-by-pixel basis, thereby projecting the desired intensity for each pixel. In both cases, collimating optics are provided to generate an output projected image collimated to infinity. As is known in the art, some or all of the above components are typically arranged on the surface of one or more polarization beam splitter (PBS) cubes or other prism arrangements.

[0069] Optical coupling from image projector 214 to LOE 212 can be achieved by any suitable optical coupling configuration, such as, for example, via a coupling prism having an angled input surface, or via a reflective coupling arrangement, via one of the side edges and / or main outer surfaces of the LOE. For illustrative purposes, the coupling configuration is schematically shown in FIG. 2 as a wedge prism 215 applied to one of the main outer surfaces of the LOE. However, as will be described in further detail below, LOEs manufactured using the methods of this disclosure can generally have different types of coupling configurations.

[0070] It will be appreciated that the near-eye display 200 includes various additional components, typically including a controller 222 for actuating the image projector 214, which typically draws power from a small onboard battery (not shown) or some other suitable power source. It will be appreciated that the controller 222 includes all the necessary electronic components for driving the image projector, such as at least one processor or processing circuitry system, all of which are well known in the art.

[0071] Now turn to Figure 2A and Figure 2BThe optical characteristics of the near-eye display implementation are shown in more detail. Specifically, a more detailed view of a light-guided optical element (LOE) 212 formed of a transparent material is shown. The LOE includes a first region 216 and a second region 218. The first region 216 includes a first optical coupling structure implemented as a first set of planar, mutually parallel partially reflective surfaces 217 with a first orientation. The second region 218 includes a second optical coupling structure implemented as a set of planar, mutually parallel partially reflective surfaces 219 with a second orientation not parallel to the first orientation. A set of mutually parallel main outer surfaces 224 extends across the first region 216 and the second region 218, such that both the first set of partially reflective surfaces 217 and the second set of partially reflective surfaces 219 are located between the main outer surfaces 24. Most preferably, the set of main outer surfaces 224 is a pair of surfaces that are each integrally continuous across the first region 216 and the second region 218, but options for decreasing or increasing the thickness between regions 216 and 218 also fall within the scope of the invention. Regions 216 and 218 may be placed side-by-side, contacting each other at their boundary, which may be a straight boundary or some other form of boundary. Alternatively, depending on the specific application, one or more additional LOE regions may exist between these regions to provide various additional optical or mechanical functions. While the invention is not limited to any particular manufacturing technique, in some particularly preferred implementations, a particularly high-quality primary outer surface is achieved by employing a continuous outer panel with separately formed regions 216 and 218 sandwiched between the continuous outer panels to form a composite LOE structure.

[0072] The optical characteristics of LOE 212 can be understood by tracing the image illumination path backward. The second set of partially reflective surfaces 219 are angled to the main outer surface 224, such that a portion of the image illumination propagating within LOE 212 from the first region 216 to the second region 218 via internal reflection at the main outer surface is coupled out of the LOE towards the eye-tracking box (EMB) 226. The first set of partially reflective surfaces 217 is oriented obliquely relative to the propagation direction of the image illumination, such that a portion of the image illumination propagating within LOE 212 via internal reflection at the main outer surface from the coupling surface (coupling configuration, in this non-limiting example, coupling prism 215) is deflected towards the second region 218.

[0073] One dimension of the angular extension of the projected image from image projector 214 is in Figure 2AThe illumination cone extends from the POD aperture on the right side of the LOE toward the left side of the LOE. In the non-limiting example shown here, the central optical axis of the image projector 214 defines the propagation direction within the LOE aligned with the X-axis, and the angular spread (within the LOE) is approximately ±16°. (It should be noted that the angular FOV becomes larger in air due to the change in refractive index.) A first set of partially reflective surfaces 217 is shown in the first region 216, and a second set of partially reflective surfaces 219 is shown in the second region 218.

[0074] The near-eye display is designed to provide the full field of view of the projected image to the eye of a user located at a position within the permissible position range specified by EMB 226 (that is, typically represented as a rectangular shape spaced apart from the plane of the LOE from which the pupil of the eye views the projected image). To reach EMB 26, light must be coupled from a second region 218 toward EMB 226 via a second set of partially reflective surfaces 219. To provide the full image field of view, each point in the EMB must receive the entire angular range of the image from the LOE. Tracing the field of view from the EMB indicates a larger rectangle 228 from which the associated illumination is coupled toward the EMB toward the LOE.

[0075] Figure 2A The first end of the field of view is shown, corresponding to the lower left pixel of the projected image. A beam of light with a width corresponding to the optical aperture of the projector when coupled into the LOE is shown propagating left and upward from the POD and partially reflected from a series of partially reflective surfaces 217. As shown here, only a subset of facets generates reflections useful for providing the corresponding pixel in the image viewed by the user, and only sub-regions of these facets contribute to the observation of the image of that pixel. The relevant regions are shown by thick black lines, and the rays corresponding to that pixel in the redirected image reflected from facet 217 and then coupled by facet 219 to reach the four corners of the EMB 26 are shown. It will be noted here, and throughout the specification, that only the in-plane propagation direction of the light during its propagation within the LOE is shown here, but the light actually follows a zigzag path of repeated internal reflections from the two main outer surfaces, and an entire dimension of the image field of view is encoded by the tilt angle of the light relative to the main outer surfaces, which corresponds to the pixel position in the Y dimension. As an additional example, the deflection and elliptical rays corresponding to the top left corner of the image viewed from the top left corner of the EMB are shown in dashed lines.

[0076] Figure 2B It shows the relationship with Figure 2A The same configuration is used, but here the light rays corresponding to the lower right pixels of the field of view that reach the four corners of the EMB are shown, and the relevant areas of the relevant part of the reflective surface 217 are indicated by thick lines.

[0077] Various methods for generating LOEs have been proposed, such as Figure 2A and 2B The image schematically illustrates an LOE. Conventional methods typically rely on stacking and bonding transparent plates optically coated with at least a partially reflective coating to form a stack, wherein the interfaces between the plates correspond to the facets of the LOE. The stack is then sliced ​​at a desired angle relative to the facet surfaces. The outer surface of the LOE should be polished to produce a high-optical-quality LOE. Additionally, and as discussed above, certain preferred implementations provide the LOE with an eyeglass shape factor. In such implementations, it may be advantageous to shape the LOE to have an eyeglass lens profile. A particular feature of certain embodiments of this disclosure is providing a method of manufacturing an LOE that, among other things, produces an LOE having a parallel and smooth primary outer surface, while having a shape according to a desired profile, in a preferred but non-limiting implementation, which is the shape of an eyeglass lens.

[0078] Now refer to Figure 3 The diagram schematically illustrates the stages (steps) of a method (process) that can be used to manufacture one or more LOEs according to embodiments of the present disclosure. As shown, a pair of optical structures (stacks) 4 and 6 are obtained. Each of optical structures 4 and 6 has a set of mutually parallel partially reflective surfaces (facets) (designated as 5 and 7, respectively). Optical structures 4 and 6 are formed by stacking and joining parallel transparent plates optically coated with at least a partially reflective coating to form the respective stacks, and then slicing the stacks at a desired angle relative to the plate surfaces, whereby the interface between the plates corresponds to facets 5 and 7.

[0079] In the illustrated embodiment, the optical structure 4 further comprises a pair of end elements 8, 9, shown herein as trapezoidal prisms, disposed at opposite ends of the stack (i.e., plates attached to the left and right ends of the stack). The trapezoidal prism shape can be obtained from the stacking slicing process. Alternatively, one or both of prisms 8 and 9 can be attached to the plate after slicing to form the optical structure 5. Each of prisms 8 and 9 has multiple surfaces. The upper surface of prism 8 is designated as 10 in the figures and may be parallel to the plane 5. As will be discussed later in this document, surface 10 may be used as a reference surface during subsequent slicing stages according to the method of this disclosure.

[0080] Optical structures 4 and 6 are combined to form a new (combined) optical structure (“stacked joint stack”) 11. Combination is achieved via joining, whereby optical structures 4 and 6 are joined together at interface 3 between the two structures 4 and 6. Optical structures 4 and 6 are joined such that facet 5 is not parallel to facet 7. Optical structures 4 and 6 can be aligned prior to joining to achieve the desired non-parallel orientation between the sets of facets 5 and 7. Interface 3 can form the boundary between two LOE regions (each containing a set of parallel facets) in the final LOE product.

[0081] Incidentally, throughout this document, the terms "joined" or "joined" should be understood to mean attached or joined with an adhesive (such as optical adhesive or glue or any other suitable adhesive). A joint between two optical structures or elements can be a direct joint in which the two structures / elements are directly attached to each other via an adhesive, or an indirect joint in which the two structures / elements are indirectly attached to each other, for example, via one or more intermediate optical structures / elements glued between the two structures / elements. Examples of intermediate optical structures include, but are not limited to, blanks providing gaps between planar optical portions, filters, polarization management elements (such as waveplates or depolarizers), etc.

[0082] The optical structure 11 is then sliced ​​along multiple parallel slicing (cutting) planes 14 intersecting interface 3 to produce one or more slices (one such slice 12 is shown in the figure). In the figure, the slicing planes 14 are represented as multiple lines, with the direction of the slices shown as arrows to generate the slicing planes. In some embodiments, the prism surface 10 may be used as a reference to define the orientation of the slicing planes 14. In a particularly preferred but non-limiting embodiment, the slicing planes 14 are perpendicular to the prism surface 10. Preferably, the slicing planes 14 are also perpendicular to the surface 15 of the optical structure 6, where the surface 15 is parallel to the facet 7. The parallel slicing planes 14 define the main outer surface of the final LOE product.

[0083] Each slice 12 is then polished from both sides (front and back, i.e., the main outer surface) and then cut along cutting line 16. Cutting line 16 (also called a contour line) has multiple sections (or segments) including contour section 18a. Contour section 18a may intersect portions of both optical structures 4 and 6 and may have one or more curved segments or segmented linear segments 15a (or combinations thereof) that intersect at least some of the facets 7 twice. Cutting along contour section 18a generates contour 18b, which gives slice 12 its contour shape. In some embodiments, contour section 18a intersects all facets 7 twice, while in other embodiments, contour section 18a intersects most facets 7 twice (most means all facets 7 except for a few, such as all facets 7 except for one, two, or three, which are typically located at the bottom portion of stack 6). In some embodiments, contour section 18a intersects some facets 5 (e.g., the first few facets 5 located closer to end prism 8). In some implementations, the contour segment 18a intersects with a portion of the end prism 8.

[0084] The cutting (contour) line 16 also includes another segment 20a intersecting a portion of the optical structure 4 as a cutting plane, which is preferably a straight segment. In some embodiments, segment 20a intersects only the optical structure 4 and not any portion of the other optical structure 6. In some embodiments, segment 20a intersects the end prism 9 and intersects with a small number (e.g., one, two, three, or four) of small planes 5 at the stacked ends closer to the end prism 9. In some embodiments, the cutting plane formed by segment 20a is angled relative to the interface 3 between the two optical structures 4 and 6.

[0085] An interface 20b is generated at the optical structure 5 by cutting slice 12 along segment 20a. This boundary surface is used to couple image illumination from the image projector and defines the coupling surface of the final LOE product. The boundary surface 20b should have good optical quality and can be polished after cutting along segment 20a. In embodiments where segment 20a is a straight segment, the boundary surface is a boundary plane (i.e., the coupling surface is a flat surface). In cases where segment 20a is not a straight segment, polishing the boundary surface 20b can help achieve flatness (flatness) of the boundary surface.

[0086] The resulting contour and polished LOE in Figure 3The LOE 22 is designated as 22. The LOE 22 is profiled (according to profile segment 18a) and includes: a pair of parallel main outer surfaces 224 (defined by a pair of adjacent cutting planes of parallel cutting planes 14), a first region 216, a second region 218, and a coupling surface (boundary surface 20b). The first region 216 has a first plurality of parallel small planes 217 formed by a portion of small planes 5, and the second region 218 has a second plurality of parallel small planes 219 obliquely inclined relative to the main outer surface of the LOE and formed by a portion of small planes 7. An image projection (i.e., a coupling optics device, such as a wedge prism) and / or an image projector can then be optically coupled to the LOE associated with the coupling surface (i.e., at the boundary surface 20b).

[0087] Although reference Figure 3 The described embodiments can be used to produce high-performance LOEs, including LOEs with high parallelism between the main outer surfaces, good optical quality of the coupled surfaces, and non-parallelism between the two sets of facets. However, the aforementioned embodiments may have certain drawbacks in terms of manufacturing efficiency. Specifically, since the cutting along the contour line 16 is performed at the slice level (i.e., per slice), a degree of repetition in the contour cutting is required that is proportional to the number of LOEs cut from the optical structure 11.

[0088] Figure 4 The illustration schematically depicts a stage of a more efficient process that can be used to manufacture one or more LOEs according to another embodiment of the present disclosure. Figure 4 The implementation shown is Figure 3 A more efficient variation of the embodiment shown. Here, the optical structure 11 is cut along a cut (profile) line, which may include segments / segments 20a' (which are similar to...). Figure 3 Segment 20a in the middle), to generate optical structure 11a. Therefore, boundary surface 20b' (which is similar to) is generated on optical structure 11a (combined stack) rather than individually on each slice. Figure 3 The boundary surface 20b' is then preferably polished to ensure optical quality and flatness (flatness), and then the optical structure 11a is sliced ​​along plane 14 as described above. Thus, after slicing, each slice already has a (preferably polished) boundary surface 20b (i.e., a portion of the boundary surface 20b'), thereby saving the steps that must be taken as described above. Figure 3 The time required to cut and polish each slice along the cutting line segment 20a, as described in the text.

[0089] It should be noted that, as in the preceding embodiments, segment 20a' is preferably a straight line segment intersecting a portion of optical structure 4 as the cutting plane. In some embodiments, segment 20a' intersects only optical structure 4 and not any portion of the other optical structure 6. In some embodiments, segment 20a' intersects with end prism 9 and, at the stacked ends closer to end prism 9, with a small number (e.g., one, two, three, or four) of small planes 5. In some embodiments, the cutting plane formed by segment 20a' is at an angle relative to the interface 3 between the two optical structures 4 and 6.

[0090] It should also be noted that, instead of or in addition to segment 20a', the contour line along which the optical structure 11 is cut may include contour segments. The contour segments may partially intersect both optical structures 4 and 6, and may have multiple segments / segments, including one or more curved segments or piecewise linear segments (similar to 18a), which intersect at least some (or most or all) of the facets 7 twice. Thus, a contoured optical structure can be produced by cutting the optical structure along the cleaving line. The optical structure can then be sliced ​​along the cleaving plane 14 to produce multiple slices, each slice having been contoured such that all slices have the same contour shape, which may include the shape of the contour segments and / or (preferably polished) boundary surfaces 20b. In such an embodiment, it is preferable that the contour segment 20a' does not intersect the end prism 8, or only intersects a small portion of the end prism 8, such that surface 10 can remain on the optical structure 4 and serve as a reference surface for the cleaving plane 14.

[0091] It should be understood that this article posits a reference... Figure 4 Variations of the described implementation. In one variation, the cutting along segment 20a' may be performed before optical structures 4 and 6 are joined together.

[0092] Figure 5 A top view schematically illustrating an additional stage of the method of this disclosure is shown. The stage shown can be applied to each slice, for example, slices generated by slicing optical structure 11 or optical structure 11a along a pair of parallel cutting planes 14. For illustrative purposes, Figure 5 The slice shown is from Figure 4 The slice generated by optical structure 11a. For example... Figure 5As shown, slice 34 is polished on both its front side 35 and rear side 36 (as discussed previously). Polishing is indicated by the thick arrow 38 in the figure. The boundary surface 20b (which is part of the boundary surface 20b' of structure 11) is shown here at the (right) edge of slice 34. Typically, the force applied to the slice during the polishing process is non-uniform, and this non-uniform polishing force can cause deformation of the slice, particularly the shape of its edges (ends). The deformed edge (including the edge where boundary surface 20b is located) is shown as 46 in the figure (not shown to scale). At the deformed edge, slice 34 can be thinner or rounded (as shown). This edge deformation can lead to performance degradation of the LOE due to poor optical coupling between the LOE and the image projection optics 48 (i.e., coupling optics, such as prisms, mirrors, PBS, or others). Figure 5 A polished slice (LOE) with a deformed edge 46 is shown, which is optically coupled (butted) to an image projection optics 48 at the deformed edge 46 (i.e., the deformed boundary surface 20b), for example, via an adhesive layer (designated 49). Due to edge distortion, a portion of the injected beam of image illumination from the projection optics 48 (represented as 50 in the figure) will be coupled into the LOE (coupled illumination represented by ray 52) and propagate through internal reflection between the main outer surfaces (front side 35 and rear side 36), but a portion of the beam 50 will also be scattered (represented by ray 54), thereby degrading image quality. Therefore, the polishing process must be closely monitored, and preferably closely monitored on hard surfaces under low pressure, to minimize the deformation of the slice (and thus the deformation of the LOE).

[0093] Figure 6 and Figure 7 The diagram schematically illustrates a stage of a process that can be used to manufacture one or more LOEs according to another embodiment of the present disclosure. Figure 6 and Figure 7 The implementation shown is Figure 4 A variation of the process is shown, maintaining the integrity of the boundary surface 20b without imposing strict polishing process constraints. (As shown) Figure 6 As shown, a blank 62 is provided at the boundary surface 20b' and temporarily attached to the optical structure 11a (with...). Figure 4 (The structure shown is the same) to form a new optical structure 11b. The temporary attachment between the blank 62 and the optical structure 11a can be achieved by a soluble adhesive or any other suitable temporary adhesive.

[0094] Optical structure 11b can then be cut along contour segment 18a' (similar to 18a) to produce contour optical structure 11c having contour 18b', which may intersect both optical structure 4 and optical structure 6, and may have multiple segments / segments, including one or more curved segments or piecewise linear segments, which intersect at least some (or most or all) of the facets 7 twice. Contour optical structure 11c can then be sliced ​​along cutting plane 14 to produce multiple slices, each slice having been contoured such that all slices have the same contour shape, and each slice including a portion of blank 62 attached to boundary surface 20b (i.e., at the coupling surface). Note that in such an embodiment, it is preferable that the contour segment does not intersect the end prism 8, or only intersects a small portion of the end prism 8, so that surface 10 can be retained and used as a reference surface for cutting plane 14.

[0095] Figure 8 An isometric view of a slice 70 extracted from an optical structure 11c by cutting along two parallel cutting planes 14 is shown. The slice 70 is contoured according to a profile segment and includes: a pair of parallel main outer surfaces (defined by a pair of adjacent cutting planes of the parallel cutting planes 14), a first region, a second region, and a coupling surface (boundary surface 20b) that may be part of the profile shape. The first region has a first plurality of parallel facets formed by a portion of facet 5, and the second region has a second plurality of parallel facets that are obliquely inclined relative to the LOE main outer surface and formed by a portion of facet 7. An image projection (i.e., coupling) optics and / or an image projector can then be optically coupled to the LOE associated with the coupling surface (i.e., at the boundary surface 20b).

[0096] Figure 7 Additional stages of the method of this disclosure that can be applied to each slice 70 extracted from optical structure 11c are schematically shown (as a top view). As previously described, the slice 70 is polished, with the thick arrow 38 indicating polishing pressure. Also as previously described, the edges 72 and 73 of the slice 70 tend to deform due to the polishing process. However, in this embodiment, the deformed edge 73 is not located at the boundary surface 20b, but is part of the blank 62, which insulates the boundary surface 20b from the polishing process. The blank 62 can then be removed from the slice 70 to produce an LOE 22 with the retained (i.e., flat and undeformed) boundary surface 20b. Figure 9An isometric view of LOE 22 is shown, which is outlined (according to outline segments) and includes: a pair of parallel main outer surfaces (defined by a pair of adjacent cutting planes of parallel cutting plane 14), a first region, a second region, and an insertion surface (boundary surface 20b) that may be part of the outline shape. The first region has a first plurality of parallel small planes formed by a portion of small plane 5, and the second region has a second plurality of parallel small planes that are obliquely inclined relative to the main outer surfaces of the LOE and formed by a portion of small plane 7. An image projection optics and / or an image projector can then be optically coupled to the LOE associated with the insertion surface (i.e., at boundary surface 20b).

[0097] The removal of blank 62 can be achieved, for example, by dissolving adhesive 64 using heat, solvent, radiation, or any other suitable method that dissolves adhesive 64 while maintaining the integrity of other adhesives in the optical structure.

[0098] Therefore, by using adhesive 49, for example (formed by slice 70 after removing blank 62), the interface between projection optics 48 and LOE 22 is uniform, and thus the illumination beam 50 is coupled into the LOE with minimal scattering (as shown by the coupled illumination 52) and propagates through internal reflection between the main outer surfaces of the LOE.

[0099] It should be understood that many variations of the embodiments described above are contemplated herein. In one variation, the contouring of the optical structure 11b can be performed on the respective optical structures 4 and 6 before they are joined together. For example, each of the optical structures 4 and 6 can be individually contoured by cutting along appropriate contoured segments that combine to form a line-like 18a when the two optical structures 4 and 6 are properly aligned, and the contoured optical structures 4 and 6 can then be joined together. Figure 4 The same applies to the optical structure 11 shown. It should also be understood that in some embodiments, the attachment of the blank 62 to the boundary surface 20b' can be performed before joining the optical structures 4 and 6 together. In such an embodiment, the optical structure 4 can be cut along the line (segment / section) 20a' before joining the two optical structures 4 and 6 together. In another variation, for example, where the integrity of the other edge 72 of the slice is desired, an additional blank (similar to blank 62) can be attached, for example, to the other end prism 8 at surface 10.

[0100] Now refer to Figure 10This schematically illustrates a stage of a process that can be used to manufacture one or more LOEs according to another embodiment of the present disclosure. Here, a soluble adhesive is not required, but as with reference to... Figures 6 to 9 This method is significantly simplified compared to the described method. The optical structure 11 (formed by the joined optical structures 4 and 6) is cut along cleaving line 16'. Cleaving line 16' is generally similar to cleaving line 16 because it includes a contour segment 18a', which may have multiple segments / segments including one or more curved segments or segmented linear segments, said multiple segments / segments intersecting at least some of the facets 7 twice. However, in this embodiment, the cleaving line does not include the segment intersecting with optical structure 4 (e.g., 20a'). Therefore, the boundary surface 20b' is not a result of cutting along cleaving line 16'. The contoured optical structure (with contour 18b) is then cut along a parallel cutting plane (i.e., plane 14, similar to the description above) to produce a slice. Figure 10 A front view of such a slice 70 is shown. The slice has a profile 18b, which is the result of cutting structure 11 along profile segment 18a'. All other slices produced by cutting along plane 14 share the same profile as the slice 70 (i.e., each slice has the same profile shape). The slice 70 can then be polished on both the front and back sides (as previously described), and the slice 70 can be cut along segment 20a to produce boundary surface 20b. In some embodiments, multiple slices can be grouped together in alignment (using, for example, mechanical fastening equipment), and can be individually cut along the cutting line (segment) 20a to simultaneously generate boundary surface 20b for each slice. The slices can also be polished together as a group at the boundary surface 20b. Alternatively, prior to polishing, a blank can be attached to the boundary surface 20b of each slice using a temporary adhesive. The blank can be removed after polishing, thereby maintaining the integrity of the boundary surface 20b.

[0101] As mentioned above, the optical structures 4 and 6 forming the bonding stack 11 can be produced by bonding stacks of parallel-plane coated plates. For example, Figure 11 An exemplary stack 1 of joined coated plates 13 is shown, wherein a shape designated 6a is cut from the stack 1 to produce an optical structure 6, and the remaining volume of the stack 1 (designated 2) is waste. To reduce (and in some cases minimize) the amount of waste when producing the base stack (e.g., optical structures 4 and 6), a “forming” stacking process can be performed. The following paragraphs describe some implementations of this disclosure utilizing formed stacks.

[0102] Now refer to Figures 12A to 13BThis shows different views of the shaped stack that can be used to form a base stack that is equivalent to (but different from) optical structure 4 and optical structure 6. Figure 12A and Figure 12B Different views are shown of an optical structure in the form of an interlaced stack 102 of coated parallel-face plates 104, which can be used to produce another optical structure equivalent to but different from optical structure 4 (in... Figure 14 (Specified as 120). The staggered placement of plates 104 can be via a group of plates in step 106, or it can be a continuous stepped stack (not shown). Stack 102 is shown as being covered (at the top and bottom) by a transparent plate 107, the thickness of which is several times the thickness of the other plates 104. In a preferred but non-limiting implementation, the shape of the stacked plates 104 can be a parallelogram (e.g., ...). Figure 12A and 12B (As shown). The parallelogram shape of the plate can help with optimal material use (i.e., reduced waste / waste). However, a rectangular shape can be used, but therefore more material will be lost as waste.

[0103] Plate 104 is joined together at multiple interfaces. At each interface, one facet of one of the plates 104 has a partially reflective coating applied thereto, which provides partially reflective optical properties. Thus, the interface forms a facet 5.

[0104] Figure 13A and Figure 13B Different views of an optical structure in the form of an interlaced stack 108 of coated parallel-faced plates 110 are shown, which is equivalent to but different from optical structure 6. The stack 108 is shown covered at the bottom by a transparent plate 109, the thickness of which is several times the thickness of the other plates 110. Here, the interlacing of the plates 110 is also achieved through a group of plates in steps 112 (however, a continuous stepped stack is also possible), and the stacked plates 110 have a parallelogram shape for optimal material use (however, a rectangular shape can be used). The plates 110 are joined together at multiple interfaces. At each interface, one face of one of the plates 110 has at least a partially reflective coating applied thereto, which provides partially reflective optical properties. Thus, the interfaces form facets 7.

[0105] Figure 14The diagram illustrates stages of a process that can be used to manufacture one or more LOEs with reduced (preferably minimal) waste (i.e., blemishes) using two stacks (optical structures) 102 and 108. As shown, stack 102 is cut (sliced) along a pair of cutting planes (shown as line 118) to generate new optical structures 120. Cutting planes 118 are preferably, but not necessarily, parallel cutting planes. Note that stack 102 can be sliced ​​multiple times along multiple cutting planes 118 to generate multiple structures 120. Optical structure 120 is equivalent to optical structure 4, wherein the same reference numerals indicate the same components.

[0106] Optical structures 120 and 108 are joined together at interface 3 to form (generate) a new (combined) optical structure 122. The optical structure 122 can then be shaped, for example, contoured, to produce a contoured optical structure 123. Figure 14 The contouring process is not shown in the diagram, but it can be referenced in the above diagram. Figure 3 , Figure 4 , Figure 6 and Figure 10 A similar technique is described to generate the contoured optical structure 123. The contoured optical structure 123 can then be sliced ​​along two or more parallel cutting planes 124 to extract one or more LOEs 128 (which can then be polished on the front and rear sides (i.e., the main outer surface)). The cutting planes 124 are diagonally (tilted) to the plate 110 (small plane 7) at a desired angle to achieve the oblique angle of the small plane (the small plane formed by the small plane 7) in the second LOE region relative to the main outer surface of the LOE 128. Therefore, slicing the optical structure 123 along the cutting plane 124 results in one or more contoured LOEs (i.e., one or more LOEs contoured according to the contoured segments), wherein all LOEs have the same contour shape and have a pair of parallel main outer surfaces (defined by the cutting plane 124), a first region, a second region, and a coupling surface (boundary surface 20b) that may be part of the contour shape. The first region has a first plurality of parallel small planes formed by a portion of the small plane 5, and the second region has a second plurality of parallel small planes that are obliquely inclined relative to the main outer surface of the LOE and formed by a portion of the small plane 7.

[0107] Figures 15A to 15C It shows the use of Figure 14 This method generates various views of LOE 128. (As shown in...) Figures 15A to 15CAs can be seen, edges 134a, 134b, and 136 (which are boundary surfaces 20b) are inclined. The inclination of edges 134a and 134b has no significant optical effect. Edge 136 (boundary surface 20b / coupled surface) is inclined such that edge 136 is obliquely inclined relative to the main outer surface of the LOE. According to some embodiments, Figure 16 A cost-effective solution to the tilt of the edge 136 (20b) schematically shown is to tilt the interface 142 of the image projector 214 relative to the tilt of the edge 136 (i.e., tilted to the main outer surface of the LOE) in a corresponding configuration such that the lower surface 150 of the projector 214 is parallel to the front (lower) main outer surface 24 of the LOE 128, and more preferably, the surface 150 forms an extension of the front main outer surface 24.

[0108] It should be understood that although the embodiments described so far involve contouring and slicing the optical structure to produce multiple slices such that all slices have the same contour shape, other embodiments are contemplated herein, in which a subset (but not all) of the slices extracted from the optical structure have the same contour shape. For example, the optical structure can be cut according to a first contour, and a first set of LOEs can be extracted from the contoured optical structure by slicing along a parallel cutting plane. Slicing can be paused, and the optical structure can be further cut according to a second contour, and then slicing can be resumed to extract a second set of LOEs from the re-contoured optical structure. Thus, the LOEs in the first set can have the same first contour shape, and the LOEs in the second set can have the same second contour shape, which is different from the first contour shape. As a non-limiting illustrative example, consider Figure 4 and Figure 6 The optical structure 11a shown is illustrated as having a profile defined by a boundary surface 20b'. The optical structure 11a can be sliced ​​along multiple cutting planes 14 to produce a first set of LOEs with the same profile shape. The remaining portion of the optical structure 11a can then be further profiled, for example by cutting along a profile segment 18a', and the re-profiled optical structure can then be sliced ​​along the cutting planes 14 to produce a second set of LOEs with the same profile shape as each other but different from the first set of LOEs.

[0109] The embodiments of the manufacturing methods described so far can be considered part of the first aspect of this disclosure, which generally include the stages of joining optical structures, contouring optical structures, and slicing optical structures to extract one or more LOEs. The second aspect of this disclosure relates to the construction of a basic optical structure with embedded facets, particularly using a method of stacking and joining parallel facet plates to generate embedded facets. This second aspect is considered to have utility independent of the first aspect. However, specific advantages may exist when the second aspect is used in conjunction with the first aspect.

[0110] As an introduction, and as discussed above, the partial reflectivity of the facets of the various optical structures described herein can be provided by applying at least partial reflection to one of the faces in a stacked parallel-face plate. For example, as referenced Figure 12A and Figure 12B As described, the parallel face plates 104 can be joined together at multiple interfaces, wherein one face of each interface (of one of the plates 104) has at least a partially reflective coating applied thereto, the coating providing partially reflective optical properties such that the interface forms a facet 5.

[0111] Figure 17 and Figure 18 The standard process for producing a conventional LOE (LOE) is illustrated (in this example, the LOE is a one-dimensional LOE because it only achieves one-dimensional aperture expansion). Figure 17 As shown, multiple parallel-faced plates 304 are stacked and joined together at multiple interfaces 305 to form a joined stack (optical structure) 308. One face at each interface 305 has a coating to provide partial reflective optical properties, such that the interfaces form a set of mutually parallel partially reflective surfaces (facets). The stack 308 is then cut (sliced) along at least two parallel cutting planes 310 that are obliquely inclined relative to the faces of the plates 304 to produce one or more LOEs 312, each LOE 312 having a pair of parallel main outer surfaces 324 (defined by a pair of adjacent cutting planes of the at least two cutting planes 312) and multiple parallel facets 319 formed by the interfaces 305 (particularly the partially reflective coatings at the interfaces 305).

[0112] Figure 18 A partial reflective coating 306 is shown in more detail at one of the surfaces of plate 304. In fact, coating 306 is smooth at the interface 303 with the surface of plate 304, but less smooth (i.e., rougher) in areas further away from interface 303. The roughness is not shown to scale in the figure and has been magnified for clarity.

[0113] Figure 19The image illumination beam 316 is shown propagating through the LOE 312 via (total) internal reflection between the main outer surfaces 324. As the beam 316 propagates, it encounters a facet 319. Some reflections from the facet 319 are necessary to gradually deflect the illumination (represented as ray 318) out of the LOE, but some reflections from the facet 319 need to be suppressed through appropriate coating design (suppressed reflections are represented by dashed ray 320). The coating should also minimize the scattering of reflected and transmitted beams.

[0114] Figure 20A and Figure 20B Showing from Figure 17 A magnified view of an interface 305 between two boards stacked 308. Figure 20A and Figure 20B In this case, two boards are designated as 304a and 304b. These boards are bonded together using adhesive. Figure 20A and Figure 20B In this process, the adhesive applied between plates 304a and 304b is designated as 307. Therefore, the coated plates bonded by the adhesive form a sandwich arrangement. The partially reflective coating 306 is made of a material layer with a different refractive index. To minimize disturbance to coating 306 and for optimal optical performance, the refractive index of adhesive 307 is designed to be approximately equal to the refractive index of plate 304. Adhesive 307 maintains the shape of the coating on one side and is planar on the other side (i.e., at the interface 303 with the surface of the plate), just like the surface of the plate. Figure 20A In this configuration, adhesive 307 is located between plate 304b and coating 306, and coating 306 is located between adhesive 307 and plate 304a. In other words, the order of the sandwich arrangement is... Figure 20A From left to right: board 304b, adhesive 307, coating 306, and board 304a. Figure 20B In this arrangement, the order of adhesive 307 and coating 306 is switched, such that coating 306 is located between plate 304b and adhesive 307, and adhesive 307 is located between coating 306 and plate 304a. In other words, the order of the sandwich arrangement is changed. Figure 20B From left to right in the middle are board 304b, coating 306, adhesive 307, and board 304a.

[0115] Figure 21A and Figure 21B The beam 316 is shown illuminating the following: Figure 20A and Figure 20B The effect on a small plane. Figure 21AIn this configuration, beam 316 illuminates facet 319 from the adhesive side. In this case, reflection originates from the rough surface of coating 306, and therefore the reflected beam (designated 318a) is scattered to some extent. The transmitted beam (designated 320a) is only slightly dispersed during transmission through a slightly non-uniform refractive interface, and therefore scattering is minimal.

[0116] exist Figure 21B In the process, beam 316 first illuminates the flat side of coating 306 (coated on plate 304b), such that reflected beam 318b originates from the flat plane and has reduced scattering. Emitted beam 320b also has minimal scattering as previously described.

[0117] Therefore, to achieve reflection and transmission while minimizing scattering, it is preferable to generate the LOE by coating each parallel surface plate on the same side and then illuminating the LOE from the same side (i.e., the coated side), such that the illumination first hits the coating. For example, the sandwich arrangement between each pair of adjacent plates could be a first plate, adhesive, coating, and second plate, with the LOE illuminating from the illumination direction such that the illumination first hits the second plate. As another example, the sandwich arrangement between each pair of adjacent plates could be a first plate, coating, adhesive, and second plate, with the LOE illuminating from the illumination direction such that the illumination first hits the first plate. Figure 22 An example of a LOE formed by a set of six parallel faces facing plates 304a, 304b, 304c, 304d, 304e, and 304f is shown, wherein the LOE has facets 319a, 319b, 319c, 319d, 319e, and 319f formed by the interfaces between the six parallel faces facing the plates 304a, 304b, 304c, 304d, 304e, and 304f. All plates 304a, 304b, 304c, 304d, 304e, and 304f are coated with a coating 306 on the same side (right side in the figure), and an adhesive 307 contacts the opposite side (left side) of the plates. Figure 23 As shown, since coating 306 is on the right side, LOE should be illuminated by beam 316 from the left side of the component panel, so that the illumination first hits the coating rather than the adhesive.

[0118] Embodiments of the second aspect of this disclosure can be used in combination with embodiments of the first aspect of this disclosure. For example, a coating and an adhesive can be applied between various parallel-facing plates to form an optical structure having a facet 5, such that at each interface between the parallel-facing plates, the adhesive is disposed between the coating (on one facet at the interface) and the other facet at the interface, such that for each interface, the boundary surface 20b is closer to the coated facet than to the adhesive facet. This arrangement ensures that illumination (injected via the boundary surface 20b) will encounter the coating (forming facets 5, 117) before the adhesive.

[0119] A similar procedure can be performed on an optical structure having facet 7. For example, a coating and adhesive can be applied between various parallel-facing plates to form an optical structure having facet 7, such that at each interface between the parallel-facing plates, the adhesive is positioned between the coating (at one facet of the interface) and the other facet of the interface, such that for each interface, optical structure 4 (and similarly, interface 3 between the two optical structures 4 and 6) is closer to the facet with the coating than to the adhesive. This arrangement ensures that illumination entering the second LOE region from the first LOE region (i.e., illumination deflected into the second LOE region by facet 117 formed by a portion of facet 5) will encounter the coating (forming facets 7, 119) before the adhesive.

[0120] It should be noted that the method of production of the present invention can be applied to a wide range of LOE structures for different applications and can be adapted to provide different parameters for the LOE. For example, although the method disclosed herein relates to producing an LOE having two immediately adjacent regions, each region having a set of parallel facets (where the facets in the two sets are not parallel to each other), the method disclosed herein can be used to manufacture an LOE having one or more intermediate regions between two facet LOE regions. Such an LOE can be manufactured by joining one or more intermediate optical structures between basic optical structures (e.g., between optical structure 4 and optical structure 6). In one embodiment, the intermediate region is a blank optically inert region that provides a gap between the two facet regions. In another embodiment, the intermediate region includes a filter. In yet another embodiment, the intermediate region includes a polarization management element such as a waveplate or depolarizer. In yet another embodiment, the intermediate region can be a facet region having facets or one or more sets of parallel facets (e.g., additional facets parallel to the main outer surface of the LOE and located in the intermediate region between the first LOE region and the second LOE region). A non-limiting example of an LOE with additional facets in an intermediate region between a first LOE region and a second LOE region is described in International Patent Application No. PCT / IL2022 / 050374. In embodiments used to produce such an LOE, the optical structure from which the LOE is cut (e.g., optical structures 11, 11a, 11c, 122, etc.) has additional facets (or a set of parallel facets) located in the region between the facets of the base optical structure (e.g., facets 5 and 7 of optical structures 4 and 6, 108 and 120, etc.), and for example parallel to the slicing plane (e.g., cutting plane 14), such that the additional facets of the final LOE product are parallel to the main outer surface of the LOE. Including additional facets in the optical structure to be sliced ​​can be implemented in different ways. In one non-limiting example, by joining one or more additional optical structures having the additional facets between basic optical structures (e.g., optical structures 4 and 6, optical structures 108 and 120, etc.), the additional facets can be included in the optical structure to be sliced, such that the basic optical structures are indirectly joined together. As another non-limiting example, one or both of the basic optical structures (e.g., optical structure 4 or optical structure 6) may include an additional facet region separate from the region containing facet 5 or facet 7, which contains the additional facets.

[0121] The embodiments described herein relate to methods for manufacturing LOEs by performing various processing stages on various optical structures. All of these optical structures can be considered intermediate work products in the LOE manufacturing process.

[0122] This document describes detailed methods for producing (i.e., manufacturing) LOEs according to various embodiments. These methods include a stage of slicing an optical structure to produce (i.e., forming, generating) slices, which can then be further processed to produce a final LOE product. However, it should be understood that, in the context of this document, each such "slice" is itself an LOE, although an LOE may be an unfinished LOE product, for example, prior to one or more further processing stages. Such further processing stages may include, for example, polishing of the main outer surface (e.g., to ensure high optical quality and / or high parallelism), contouring (e.g., to resemble the shape of an eyeglass lens), cutting (e.g., to produce boundary surfaces, i.e., coupling regions / surfaces), polishing of the boundary surfaces (e.g., to ensure high flatness), and other fine-tuning stages.

[0123] It should be understood that the joining optical structures described herein are aligned before the joining stage or, in some cases, during the joining stage. Alignment of various optical structures can be performed using any suitable optical alignment device / apparatus / tool ​​that performs a suitable optical alignment technique / method. Such a suitable optical alignment device / apparatus / tool ​​may include, for example, one or more computerized control devices, one or more computerized processing devices, one or more optical subsystems having, for example, one or more light sources, one or more photodetectors / sensors (including optical sensors), one or more optical components (e.g., one or more lenses, one or more folding optics, one or more prisms, etc.), autocollimators, etc. Details of non-limiting examples of suitable optical alignment devices / apparatus / tools / methods that can be used to align the various optical structures described herein can be found in various publications of Lumus Ltd. (Israel), including, for example, International Patent Application No. PCT / IL2021 / 051377 and International Patent Application No. PCT / IL2021 / 051378.

[0124] This disclosure describes various cutting and slicing stages in which optical structures are cut along cutting lines and / or planes to produce a variety of other optical structures or optical products. In some embodiments, as discussed above, some or all surfaces of these optical structures (including, and particularly, those surfaces produced by these cutting stages) may be polished to, for example, improve optical quality. In some embodiments, polishing may be performed as part of these cutting stages or after these cutting stages and before a subsequent optical coupling (e.g., bonding) stage. In the manufacturing methods described above, as will be understood by those skilled in the art, the cutting or slicing of the various optical structures described herein can be performed using any suitable cutting equipment / apparatus / tool. As will be understood by those skilled in the art, the polishing of the faces and surfaces of the various optical structures described herein can be performed using any suitable polishing equipment / apparatus / tool.

[0125] Various embodiments of this disclosure have been described for illustrative purposes, but such description is not intended to be exhaustive or limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein has been chosen to best illustrate the principles of the embodiments, their practical application, or technical improvements to technologies found in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

[0126] As used in this article, unless the context clearly indicates otherwise, the singular forms “a,” “one,” and “the” include plural references.

[0127] The term "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations and / or excludes features derived from other implementations.

[0128] It should be understood that, for clarity, certain features of the invention described in the context of a single embodiment may also be provided in combination in a single embodiment. Conversely, for brevity, various features of the invention described in the context of a single embodiment may also be provided individually or in any suitable sub-combination or suitably provided in any other described embodiment of the invention. Certain features described in the context of various embodiments should not be considered essential features of those embodiments unless the embodiment is inoperable without these elements.

[0129] Although the invention has been described in conjunction with specific embodiments thereof, it will be apparent to those skilled in the art that many alternatives, modifications, and variations will be apparent. Therefore, the invention is intended to include all such alternatives, modifications, and variations falling within the spirit and broad scope of the appended claims.

Claims

1. A method for manufacturing one or more light-guiding optical elements (LOEs), the method comprising: A first optical structure having a first set of partially reflective surfaces that are parallel to each other is obtained; A second optical structure having a second set of partially reflective surfaces that are parallel to each other is obtained; The first optical structure and the second optical structure are joined together such that the first set of partial reflective surfaces are not parallel to the second set of partial reflective surfaces, to form a third optical structure; Cut at least one of the first optical structure or the second optical structure along the contour line; as well as The third optical structure is sliced ​​along at least two parallel cutting planes to form one or more LOEs, each of which is contoured according to the contour line, such that all LOEs in the one or more LOEs have the same contour shape.

2. The method according to claim 1, wherein, Before joining the first optical structure and the second optical structure together, a segment of the contour line is cut.

3. The method according to claim 1, wherein, Cutting along the contour line is performed by cutting the third optical structure.

4. The method according to claim 1, wherein, The contour line includes a segment that intersects a portion of the first optical structure to define a boundary surface at the first optical structure, the boundary surface defining the coupling surface of each of the one or more LOEs.

5. The method according to claim 4, further comprising: The boundary surface is polished.

6. The method according to claim 4, wherein, The segment is a substantially straight line segment, such that the boundary surface defined by the second segment is a boundary plane.

7. The method according to claim 4, further comprising: For each of the one or more LOEs, a coupling optics device is bonded to the coupling surface.

8. The method according to claim 4, further comprising: Before slicing the third optical structure, a blank is attached at the boundary surface such that each of the one or more LOEs has a portion of the blank located at the coupling surface.

9. The method according to claim 8, further comprising: For each of the one or more LOEs, a pair of parallel main outer surfaces are polished; as well as Remove the portion of the blank located at the coupling surface.

10. The method of claim 4, further comprising: For each of the one or more LOEs, an image projector is optically coupled to the LOE associated with the coupling surface.

11. The method according to claim 4, wherein, For each of the one or more LOEs, the coupling surface is a planar surface obliquely inclined relative to a pair of parallel main outer surfaces, and wherein the method further comprises: for each of the one or more LOEs, optically coupling an image projector to the LOE, the coupling being between an interface of the image projector and the planar surface, wherein the interface is obliquely inclined relative to the pair of parallel main outer surfaces.

12. The method according to claim 1, wherein, The first optical structure includes a reference surface, wherein the at least two parallel cutting planes are perpendicular to the reference surface.

13. The method according to claim 1, wherein, The third optical structure includes an intermediate optical structure between the first optical structure and the second optical structure.

14. The method according to claim 13, wherein, The intermediate optical structure is optically inert.

15. The method according to claim 13, wherein, The intermediate optical structure includes one or more filters or polarization management elements.

16. The method according to claim 13, wherein, The intermediate optical structure has at least one partially reflective surface, which is located between the first set of partially reflective surfaces and the second set of partially reflective surfaces and is parallel to the at least two cutting planes.

17. The method according to claim 1, wherein, The first optical structure is formed by an alternating stack of parallel-faced plates joined together at multiple interfaces, one face at each interface having a coating to provide partial reflective optical properties, such that the interfaces form the first set of mutually parallel partially reflective surfaces.

18. The method according to claim 1, wherein, Obtaining the first optical structure includes: Multiple parallel faces are joined together at multiple interfaces to form a stack of plates, with one face at each interface having a coating to provide partially reflective optical properties. The stack is cut along a pair of cutting planes that intersect at least some of the interfaces.

19. The method according to claim 18, wherein, Joining the plurality of parallel-faced panels together includes: at each interface, providing an adhesive between the coating and another face at the interface, wherein, for each interface, the boundary surface is closer to the face with the coating than to the adhesive.

20. The method according to claim 1, wherein, The second optical structure is formed as an alternating stack of parallel-faced plates joined together at multiple interfaces, one face at each interface having a coating to provide partial reflective optical properties, such that the interfaces form the second set of mutually parallel partial reflective surfaces.

21. The method according to claim 1, wherein, Obtaining the second optical structure includes: Multiple parallel faces are joined together at multiple interfaces to form a stack of plates, with one face at each interface having a coating to provide partially reflective optical properties. The stack is cut along a pair of cutting planes that intersect at least some of the interfaces.

22. The method according to claim 21, wherein, Joining the plurality of parallel-faced plates together includes: at each interface, providing an adhesive between the coating and another face at the interface, wherein, for each interface, the first optical structure is closer to the face having the coating than to the adhesive.

23. A method for manufacturing one or more light-guiding optical elements (LOEs), the method comprising: A first optical structure and a second optical structure are obtained, wherein the first optical structure has a first set of partially reflective surfaces that are parallel to each other, and the second optical structure has a second set of partially reflective surfaces that are parallel to each other. The first optical structure and the second optical structure are joined together such that the first set of partial reflective surfaces are not parallel to the second set of partial reflective surfaces, to form a third optical structure; Cut the first optical structure and the second optical structure along the contour line; The third optical structure is sliced ​​along at least two parallel cutting planes to form one or more LOEs, each of the one or more LOEs being contoured according to the contour line, such that all LOEs of the one or more LOEs have the same contour shape. as well as Each of the one or more LOEs is cut along a substantially straight cutting line that intersects a portion of the first region to define the coupling surface of the LOE.

24. The method according to claim 23, wherein, Cutting each of the one or more LOEs along the substantially straight cutting line is performed using a single cutting pair of multiple LOEs held together.

25. The method of claim 24, further comprising: For each of the one or more LOEs, a coupling optics device is bonded to the coupling surface.

26. A method for manufacturing one or more light-guiding optical elements (LOEs), the method comprising: A first optical structure having a first set of partially reflective surfaces that are parallel to each other is obtained; A second optical structure having a second set of partially reflective surfaces that are parallel to each other is obtained; The first optical structure and the second optical structure are joined together such that the first set of partial reflective surfaces are not parallel to the second set of partial reflective surfaces, to form a third optical structure; Cut along a cutting line, the cutting line including a segment intersecting a portion of the first optical structure to define a boundary surface at the first optical structure; The blank is attached at the boundary surface; as well as The third optical structure is sliced ​​along at least two parallel cutting planes to form one or more LOEs, each of the one or more LOEs having an insertion surface defined by the boundary surface and having a portion of the blank located at the insertion surface.

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