Optical device ventilation gap for edge sealants and laminated dams

Abstract

To provide optical device venting gap(s) for edge sealant and lamination dam.SOLUTION: An optical device (for example, an eyepiece) includes a plurality of layers of waveguides. The optical device can include: an edge sealant for reducing light contamination; a lamination dam for restricting the wicking of the edge sealant between layers of the optical device; and venting gap(s) in the sealant and dam for allowing an air flow between the exterior and interior of the eyepiece. The gap(s) allow outgassing from the interior of the eyepiece of unreacted polymer and / or accumulated moisture for preventing defect accumulation caused by chemical reaction of outgassed chemicals with the surface (for example, ionic, acidic, or the like) of the eyepiece layers. The gap(s) also prevents pressure differences which may physically deform the eyepiece over time.SELECTED DRAWING: Figure 1

Description

[Background technology]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Patent Application No. 62 / 702,215, entitled "OPTICAL DEVICE VENTING GAPS FOR EDGE SEALANT AND LAMINATION DAM," filed July 23, 2018, and U.S. Patent Application No. 62 / 702,020, entitled "OPTICAL DEVICE VENTING GAPS FOR EDGE SEALANT AND LAMINATION DAM," filed July 23, 2018.

[0002] (background) In optical devices, light can be directed and / or manipulated to achieve a desired effect. For example, in optical devices such as eyepieces used in virtual reality interfaces, visible light can be directed and / or manipulated to provide image data that is perceived by a user. Various types of optical devices may undergo testing during and / or after manufacture to ensure that the device is manufactured and / or operates according to desired specifications. For example, in some types of optical devices, it may be advantageous to reduce or eliminate leakage of light out of the device. Summary of the Invention [Means for solving the problem]

[0003] Embodiments of the present disclosure are generally directed to optical devices with one or more vent gaps. More specifically, the embodiments are directed to optical devices (e.g., eyepieces) that include multiple optical layers including an edge sealant along at least a portion of the periphery of the optical device, a laminate dam to limit wicking of the edge sealant, and one or more vent gaps in the laminate dam and edge sealant to allow air flow between the interior and exterior of the optical device. The air flow provided by the vents also allows escape of unreacted polymer residue and moisture from areas between the layers of the optical device when the optical device is exposed to heat and humidity conditions (e.g., about 45-65 degrees Celsius at about 80-100% relative humidity).

[0004] In general, innovative aspects of the subject matter described herein can be included in one or more embodiments of an optical device including a plurality of optical layers, an edge sealant arranged along an edge of the optical device across the plurality of optical layers, where one or more sealant gaps are present in the edge sealant, and a stacked dam arranged between each pair of adjacent layers of the plurality of optical layers to stop wicking of the edge sealant between the optical layers at a distance from the edge of the optical device, where one or more dam gaps are present in the stacked dam at one or more locations along the edge, each corresponding to a location of a respective sealant gap, to allow air flow between the interior and exterior of the optical device through the one or more sealant gaps and the one or more dam gaps. The innovative aspects of the subject matter described herein can be included in one or more embodiments of an eyepiece including an embodiment of the optical device.

[0005] One or more embodiments can optionally include one or more of the following features.

[0006] In some embodiments, the one or more sealant gaps are located outside a critical area at the edge of the optical device.

[0007] In some embodiments, one or more of the sealant gaps has a length along the edge of the optical device that exceeds the length of the corresponding dam gap.

[0008] In some embodiments, one or more of the edge sealant, the laminate dam, and a surface of one of the optical layers of the plurality of optical layers comprises or is at least partially composed of a hydrophobic material.

[0009] In some embodiments, at least one of the one or more sealant gaps at least partially overlaps with a corresponding one of the one or more dam gaps along an edge of the optical device.

[0010] In some embodiments, at least one of the one or more sealant gaps is concentric with a corresponding one of the one or more dam gaps.

[0011] In some embodiments, the edge sealant includes at least two sealant gaps and the laminate dam includes at least two dam gaps.

[0012] In some embodiments, the plurality of optical layers comprises at least three optical layers, the at least three optical layers including a layer for guiding red light, a layer for guiding green light, and a layer for guiding blue light.

[0013] In some embodiments, the edge sealant absorbs ultraviolet radiation.

[0014] In some embodiments, at least one of the optical layers of the plurality of optical layers includes an orthogonal pupil expander region.

[0015] In some embodiments, at least one of the optical layers of the plurality of optical layers includes an exit pupil expander region.

[0016] In some embodiments, at least one of the optical layers of the plurality of optical layers includes an internal lattice bonding region.

[0017] In some embodiments, the one or more sealant gaps and the one or more edge gaps allow air flow between an interior of the optical device and an exterior of the optical device.

[0018] In some embodiments, the edge sealant prevents light leakage from the interior to the exterior of the optical device in a transverse direction through the edges of the optical device.

[0019] In some embodiments, the edge sealant prevents light reflection into the interior of the eyepiece.

[0020] In some embodiments, the edge sealant thickness is in the range of about 430 microns to about 500 microns.

[0021] In some embodiments, the thickness of the edge sealant between the edge of the optical device and the laminate dam is about 350 microns.

[0022] In some embodiments, the width of the laminate dam is about 500 microns.

[0023] In some aspects, the eyepiece includes.

[0024] It should be understood that the aspects and features according to the present disclosure can include any combination of the aspects and features described herein, i.e., the aspects and features according to the present disclosure are not limited to the combination of the aspects and features specifically described herein, but include any combination of the aspects and features provided.

[0025] The details of one or more embodiments of the disclosure are set forth in the accompanying drawings and the description below. Other features and advantages of the disclosure will be apparent from the description and drawings, and from the claims. For example, the present invention provides the following: (Item 1) 1. An optical device comprising: A plurality of optical layers; an edge sealant disposed along an edge of the optical device across the plurality of optical layers, wherein one or more sealant gaps are present within the edge sealant; a stacking dam disposed between each pair of adjacent optical layers of the plurality of optical layers to stop wicking of the edge sealant between the optical layers at a distance from an edge of the optical device, wherein one or more dam gaps are present in the stacking dam at one or more locations along the edge, each corresponding to a location of a respective sealant gap, to allow air flow between an interior and an exterior of the optical device through the one or more sealant gaps and the one or more dam gaps; An optical device comprising: (Item 2) Item 10. The optical device of item 1, wherein the one or more sealant gaps are located outside a critical area at an edge of the optical device. (Item 3) Item 10. The optical device of item 1, wherein one of the one or more sealant gaps has a length along an edge of the optical device that exceeds a length of the corresponding dam gap. (Item 4) Item 10. The optical device of item 1, wherein one or more of the edge sealant, the laminate dam, and a surface of one of the optical layers of the plurality of optical layers are at least partially composed of a hydrophobic material. (Item 5) Item 1 , wherein at least one of the one or more sealant gaps at least partially overlaps a corresponding one of the one or more dam gaps along an edge of the optical device. (Item 6) Item 1, wherein at least one of the one or more sealant gaps is concentric with a corresponding one of the one or more dam gaps. (Item 7) the edge sealant includes at least two sealant gaps; Item 2. The optical device of item 1, wherein the stacked dam includes at least two dam gaps. (Item 8) Item 2. The optical device of item 1, wherein the plurality of optical layers comprises at least three optical layers. (Item 9) Item 9. The optical device of item 8, wherein the at least three optical layers comprise a layer for guiding red light, a layer for guiding green light, and a layer for guiding blue light. (Item 10) Item 14. The optical device of item 1, wherein the edge sealant absorbs ultraviolet radiation. (Item 11) Item 10. The optical device of item 1, wherein at least one of the optical layers of the plurality of optical layers comprises an orthogonal pupil expander region. (Item 12) Item 14. The optical device of item 1, wherein at least one of the optical layers of the plurality of optical layers comprises an exit pupil expander region. (Item 13) Item 10. The optical device of item 1, wherein at least one of the optical layers of the plurality of optical layers comprises an internal grating bonding region. (Item 14) Item 1 , wherein the one or more sealant gaps and the one or more edge gaps allow air to flow between an interior of the optical device and an exterior of the optical device. (Item 15) Item 2. The optical device of item 1, wherein the edge sealant prevents light leakage from the interior to the exterior of the optical device in a transverse direction through the edges of the optical device. (Item 16) 2. The optical device of claim 1, wherein the edge sealant prevents light reflection into the interior of the eyepiece. (Item 17) Item 2. The optical device of item 1, wherein the edge sealant has a thickness in the range of about 430 microns to about 500 microns. (Item 18) Item 1 . The optical device of item 1 , wherein the thickness of the edge sealant between the edge of the optical device and the laminate dam is about 350 microns. (Item 19) Item 2. The optical device of item 1, wherein the width of the laminate dam is about 500 microns. (Item 20) An eyepiece comprising the optical device described in item 1. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 depicts a schematic diagram of an exemplary eyepiece, according to an embodiment of the present disclosure.

[0027] [Diagram 2] FIG. 2 depicts a schematic diagram of a portion of an exemplary eyepiece, according to an embodiment of the present disclosure.

[0028] [Diagram 3] FIG. 3 depicts a cross-sectional schematic view of an exemplary optical device that can be inspected using an inspection apparatus according to an embodiment of the present disclosure.

[0029] [Figure 4] FIG. 4 depicts an exemplary dam arrangement within an eyepiece according to an embodiment of the present disclosure.

[0030] [Diagram 5] FIG. 5 depicts a schematic diagram showing an example deformation of the layers of the eyepiece lens, such as in the absence of an air vent.

[0031] [Figure 6] 6A and 6B are scanning electron microscope (SEM) images showing eyepiece deformations with and without vents, respectively, according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] Embodiments of the present disclosure are directed to an optical device (e.g., an eyepiece) that includes an edge sealant to reduce light contamination, a laminated dam to limit wicking of the edge sealant between layers of the optical device, and an air gap in the sealant and dam to allow outgassing from the interior of the eyepiece and prevent pressure differentials from occurring. The gap can allow air to flow between the interior and exterior of the eyepiece and prevent defects and / or deformations that may otherwise be caused by chemical reactions and / or pressure differentials.

[0033] The eyepiece can be constructed to include multiple layers of waveguides as described below. During manufacture of the eyepiece, an edge sealant (e.g., a polymer) can be applied along at least a portion of the periphery of the eyepiece. The sealant can be subsequently cured using ultraviolet (UV) light directed at the edge sealant. The eyepiece can also be manufactured to include a stacked dam that limits the sealant material from wicking between layers of the eyepiece beyond a certain depth before the sealant material is fully cured. In some examples, an edge sealant is applied to the optical device to prevent (or at least reduce) light leakage from the optical device and also to secure and maintain the structure of the multi-layered optical device. In some examples, the optical device is an eyepiece manufactured for use in a virtual reality, augmented reality, and / or computer vision interface device and / or for delivering image data, video data, graphics data, and / or other types of visually perceptible information to a user wearing or otherwise using the interface device. A sealant may be applied to absorb light emanating out of the eyepiece and prevent the light from reflecting back into the eyepiece and degrading its optical performance.

[0034] The sealant can be applied to at least a portion of the edge of the eyepiece, with application across the entire thickness of the eyepiece across all layers of the multi-layer eyepiece. When the sealant is applied to the multi-layer structure, it begins to wick between the layers of the eyepiece. Thus, curing of the sealant can be initiated immediately (e.g., immediately after) completion of the sealant application. Various factors can contribute to the amount of wicking that occurs (e.g., wicking length), including the particular material used for the sealant and its viscosity, the delay before curing begins, and / or inflow material variations (e.g., air gap size between layers within the eyepiece). For example, the smaller the air gap between layers, the more wicking can occur due to capillary effects. In some embodiments, the curing and sealant application can be consistent such that all portions of the sealant (e.g., all portions of the edge) can have the same or substantially the same wicking time. In some embodiments, stacked dams are arranged between the layers of the eyepiece to stop the wicking of the sealant at a particular depth, as described further below.

[0035] In some embodiments, one or more (e.g., ultraviolet) light sources (probes) can be employed to cure the sealant. For example, the sealant can be a black UV-sensitive polymer that cures upon exposure to UV light for a length of time. The use of a sealant can enhance the optical performance of the eyepiece in terms of brightness and / or contrast, while also providing mechanical strength and structural integrity to the multi-layer structure of the eyepiece.

[0036] If the sealant is applied continuously along the entire circumference of the eyepiece without any gaps in the sealant and stacked dam, the optical performance of the eyepiece (e.g., in terms of contrast, efficiency, etc.) may deteriorate over time due to the accumulation of defects. Such defects may be caused when chemicals generated through outgassing of the sealant and / or dam material react with chemicals present in the eyepiece (e.g., chemicals at the surface of the optical layer). The defects may accumulate over time on the optical lattice of each optical layer, leading to optical aberrations during eyepiece operation (e.g., double images, blurring, ghost images, etc.). Furthermore, without gaps, the optical layers may deform over time due to pressure differences in trapped air gaps caused by altitude and / or temperature changes. Such pressure differences may appear between layers within the eyepiece and / or between the interior and exterior of the eyepiece, causing substantial mechanical deformation of the eyepiece structure.

[0037] The embodiments employ one or more ventilation gaps through both the dam and the sealant, which allow air flow between the interior and exterior of the eyepiece. Through the use of gaps, the embodiments allow flow of outgassed chemicals to the exterior of the eyepiece, thus reducing contamination of the optical lattice as described above. The gaps also allow air pressure balance across the layers and between the interior and exterior of the eyepiece, thus reducing or eliminating mechanical deformation caused by pressure differences over time. Gaps in the dam and sealant can be provided in substantially the same locations in the dam and sealant coatings along the circumference of the eyepiece to allow air flow. For example, the gaps in the sealant can be concentric with the gaps in the dam or can otherwise at least partially overlap with the gaps in the dam. In some embodiments, there may be a difference in the width of the gaps in the dam compared to the width of the gaps in the sealant, as described further below, to avoid wicking of the sealant into the interior of the eyepiece through the gaps in the dam.

[0038] Eyepieces with and without gaps were tested and compared, and the tests demonstrated that the use of gaps helps reduce defect deposition on the lattice of the optical layers, thus improving optical key performance indicators (KPIs) such as contrast and efficiency. Through mechanical simulation of an eyepiece without vents, it was determined that the layers of the eyepiece can be deformed as much as 95 micrometers by pressurizing the inside and outside to sea level, then setting the outside pressure to the air pressure at 10,000 feet altitude, and finally returning to sea level. This deformation can introduce crosstalk between the optical layers that causes double or ghost images in optical displays. The use of gaps improves eyepiece performance by reducing or preventing instances of defect deposition and pressure-based deformation of the eyepiece.

[0039] In some embodiments, the materials used for the lamination dam and edge seal adhesive and for the surfaces of the optical layers may be hydrophobic to avoid moisture condensation that may otherwise occur between layers when gaps are present. The lamination dam, in some embodiments, is a curable optical glue that is dispensed over the spacer of a specified height (e.g., 50 microns, but dependent on optical design). In some embodiments, the curable glue incorporates the spacer beads themselves. The spacer beads may be glass or polymer to meet refractive index and structural requirements.

[0040] In some embodiments, the eyepiece comprises a suspension of polymer glue and soda lime silica glass beads, the glass beads being present to maintain an air gap and an offset between the interior and exterior of the optical device. The offset is defined by the size of the glass beads and is present to enhance the mechanical properties of the layers by reducing warping and bending and increasing mechanical strength. In some embodiments, the laminate dam suspension has a viscosity equal to or greater than 70,000 centipoise (cP) at room temperature. In some embodiments, the soda lime silica glass beads have a dimension equal to or greater than 20 microns.

[0041] FIG. 1 depicts a schematic diagram of a top-down view of an exemplary eyepiece 102, according to an embodiment of the present disclosure. As shown in this example, the eyepiece 102 can include various eyepiece lattice regions, including an orthogonal pupil expander (OPE) region 104, an exit pupil expander (EPE) region 106, and an internal coupling grating (ICG) region 108. The eyepiece 102 can include a sealant 114 (also described as an edge seal or edge sealant) around at least a portion of the periphery of the eyepiece 102, as described above. The eyepiece 102 can also include a laminate dam 116 (also described as a dam) arranged between layers of the eyepiece 102 to stop possible wicking of the sealant material before the sealant is fully cured. The eyepiece 102 can include one or more ventilation gaps 110 (also described as gaps) within the sealant 114 and dam 116, which allow air flow between the interior and exterior of the eyepiece 102. Such flow can allow for outgassing 118 of gases generated during hardening of the sealant and / or dam material and prevent the creation of pressure differences that can cause physical deformation of the eyepiece lens layers.

[0042] In some embodiments, a portion of the periphery of the eyepiece 102 can be characterized as a critical region 112, also described as a critical optical path. Along the critical path, the presence of the sealant absorbs light along the edge of the eyepiece 102 and prevents optical aberrations, as described above. Thus, the gaps 110 can be located along the periphery at locations that are not within the critical region, since gaps in the critical region can cause optical aberrations due to light reflecting back into the eyepiece. The eyepiece 102 can include any suitable number of gaps 110, and each gap 110 can have a suitable length. Each gap 110 can include both gaps in the sealant and gaps in the dam. The gaps 110 can be approximately the same location and length in both the dam 116 and the sealant 114 to provide adequate airflow through both the dam 116 and the sealant 114. In some embodiments, the length of the gap 110 may vary slightly between the dam 116 and the sealant 114, as described further below.

[0043] FIG. 2 depicts a schematic diagram of a portion of an exemplary eyepiece 102, according to an embodiment of the present disclosure. The specific dimensions and tolerances (in millimeters) shown in FIG. 2 are provided as an example, and embodiments are not limited to the example dimensions and tolerances shown. The dashed lines indicate variations in the positioning of the gaps 110 in the sealant 114 and the dam 116. FIG. 2 illustrates an embodiment in which the eyepiece 102 includes one or more gaps 110 that allow air flow through both the sealant 114 and the dam 116. In some embodiments, as shown in this example, the length of the gaps 110 through the sealant 114 is different than the length of the gaps 110 through the dam 116. For example, the length of the gaps 110 through the dam 116 may be less than the length of the gaps 110 through the sealant 114. The difference in length may be to prevent the sealant 114 from wicking into the interior of the eyepiece 102 through the gaps in the dam 116. Also, as shown, the gap 110 in the sealant 114 can begin at a location outside of the critical area of ​​the eyepiece periphery.

[0044] In one example, the edge seal and laminate dam gaps are concentric 4 mm away from the top corner of the OPE. The vent gap size can be 3 mm and can vary from a minimum of 1 mm to a maximum of 5 mm. The laminate vent gap can be positioned with an accuracy defined as ±1 mm, and the edge seal vent gap can be positioned with an accuracy defined as ±2 mm. In some embodiments, the edge seal vent gap size can be determined based on the laminate dam vent gap size. The edge seal vent gap can have a safety zone of 1 mm from the edge of the laminate dam vent gap to prevent sealant from leaking into the dam vent gap. The edge seal can remain within a critical region or critical optical path (e.g., with an end point defined by the intersection of an extension of the OPE grid with the glass edge as depicted by a dashed line) to avoid the presence of a gap in the critical region.

[0045] FIG. 3 depicts a cross-sectional schematic 300 of an exemplary optical device 102 (e.g., an eyepiece) according to an embodiment of the present disclosure. The diagram shown is a cross-section of an exemplary eyepiece. As shown, the eyepiece can include multiple layers 302, each providing a waveguide for a particular wavelength band of light. For example, different layers may be designed to guide red, green, or blue light. An edge sealant 114 may be applied to the edge of the eyepiece as shown to attempt to prevent light leakage 310 from the inside to the outside of the eyepiece in the transverse direction through the edge. The edge sealant 114 may also prevent light reflection back into the interior of the eyepiece. The edge sealant 114 may be applied with an appropriate thickness 306 and may penetrate (through wicking) into the eyepiece to an appropriate depth 308 between the layers 302. The eyepiece may be made of multiple layers of (e.g., high index) glass in a stack. Dams 116 can also be used to stop wicking of sealant 114. As shown in the example, dams 116 can be arranged between layers 302 at a particular depth 308 relative to the edge of the eyepiece 102 to stop wicking of sealant 114 at the depth 308.

[0046] The ventilation gaps described herein can be used in any suitable type of optical device. In some embodiments, the eyepiece is a Molecular Imprints TM Jet and flash imprint technology (J-FIL) developed by TM ) at least in part. The J-FIL technique may be used to create a grating on a layer of glass of the eyepiece to create a waveguide display. Each layer may be a thin layer of glass with a polymer grating created on its surface using J-FIL. The grating may provide the basic operational functionality of the eyepiece. Once the grating is formed on a large and wide layer of glass, the glass layer may be laser cut into the shape of the eyepiece. Each layer of glass may be a different color and there may be multiple depth planes. Multiple planes may provide a better virtual experience for a user using the eyepiece. The layers may be stacked using a sealant polymer (e.g., glue dots or lines) and the entire stack may be sealed using a sealant. The air gap between the layers may be preserved for the optical performance of the eyepiece. The gap between the layers may have a controlled dimension (e.g., approximately uniform width). An edge sealant polymer may be applied around the edges of the layered structure to seal the stack and the air gap from the outside environment. The edge seal glue also provides a physical lock to ensure the mechanical integrity of the structure while preventing external particle contamination and / or reducing the possibility of moisture accumulation. Without such a seal, the layers may collapse and delaminate from one another. The gap between the layers may have any suitable width to achieve the desired optical functionality.

[0047] The use of the sealant allows for the creation of a high contrast eyepiece by absorbing stray light that strikes the edges of the eyepiece layers. The sealant also provides structural integrity (e.g., "fixes") for the mechanical clearance and coplanarity of the eyepiece. The eyepiece may have any suitable number of layers 302 of glass or other materials, and each layer may act as a waveguide to allow the passage of various frequencies of light. The layers may be configured for specific wavelengths to propagate specific colors of light, and the eyepiece may be configured for specific optical powers to create several depth planes where light through the waveguides may be perceived. For example, a first set of waveguide layers may include layers for red, green, and blue at a first depth plane, and a second set of waveguide layers may include a second set of layers for red, green, and blue light corresponding to a second depth plane. The order of the colors may be arranged differently at different depth planes to achieve a desired optical effect in the eyepiece. In some embodiments, a single (e.g., blue) layer may cover multiple depth planes. In some examples, the edge sealant may be a glue, resin, polymer sealant, ink, and / or other viscous material. The edge sealant may be black. Blackening the edges of a multi-layered eyepiece may cause absorption of light that strikes the edge and / or may provide reduced reflection of light that strikes the edge.

[0048] FIG. 4 depicts an exemplary dam arrangement in an eyepiece according to an embodiment of the present disclosure. Units shown are microns. For example, the thickness of the sealant from the edge of the glass may be 80-150 microns, and the wicking depth of the sealant may be 350 microns, until wicking is stopped by the dam. The dam may be 500 microns wide and separated from the grid boundary of the eyepiece by a gap that is 650 microns wide. The distance between the edge of the glass and the grid boundary may be 1500 microns (1.5 mm). Other suitable dimensions may also be employed.

[0049] FIG. 5 depicts a schematic diagram showing an example deformation of layers of an eyepiece 500, such as in the absence of an air vent. For example, the eyepiece may include a 250 micron optical layer with 25 micron spacing, nine depth planes, and two cover glass layers, for a total of 11 layers. In a test condition, the environment inside and outside the eyepiece was first pressurized to sea level pressure. The outside air pressure was set to the air pressure at 10,000 feet altitude and then returned to sea level pressure. As a result, the pressure difference caused some out-of-plane deformation of the layers within the eyepiece, up to 95 microns of out-of-plane deformation.

[0050] 6A and 6B are scanning electron microscope (SEM) images showing eyepiece defects with and without vents, respectively, according to embodiments of the present disclosure. In the example of FIG. 6A, image 600 shows a scanning electron microscope (SEM) image of an eyepiece region without vents (e.g., the region between the OPE and EPE) after 1000 hours of heat and humidity testing in which the eyepiece is exposed to 65 degrees Celsius and 95% relative humidity. Image 602 in FIG. 6B shows an SEM image of an eyepiece region in an eyepiece including vents that was exposed to similar test conditions. As shown, the presence of vents dramatically reduces and / or eliminates the occurrence of contamination defects in the eyepiece.

[0051] Although the present specification contains many specific details, these should not be interpreted as limitations on the scope of the disclosure or what may be claimed, but rather as examples of features associated with a particular embodiment. Certain features described herein in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, although features may be described above as acting in a combination and even initially claimed as such, one or more features from the claimed combination may in some examples be deleted from the combination, and the claimed combination may be directed to a subcombination or a variation of the subcombination.

[0052] Several embodiments have been described. Nevertheless, it should be understood that various modifications may be made without departing from the spirit and scope of the present disclosure. For example, the various structures shown above may be used with elements rearranged, positioned differently, oriented differently, added, and / or removed. Thus, other embodiments are within the scope of the following claims.

Claims

1. An optical device, comprising: A plurality of optical layers; an edge sealant disposed along an edge of the optical device across the plurality of optical layers, wherein one or more sealant gaps exist within the edge sealant; a stacking dam disposed between each pair of adjacent optical layers of the plurality of optical layers to stop wicking of the edge sealant between the plurality of optical layers at a distance from the edge of the optical device, wherein one or more dam gaps are present in the stacking dam at one or more locations along the edge, each of the one or more dam gaps corresponding to a location of a respective sealant gap to allow air flow between an interior and an exterior of the optical device through the one or more sealant gaps and the one or more dam gaps; Equipped with one of the one or more sealant gaps is located outside of a critical area of ​​the edge of the optical device, the critical area being defined as a portion of a periphery of the optical device; The edge sealant is at least partially disposed within the critical region, the edge sealant absorbing light along the critical region.

2. The optical device of claim 1 , wherein one or more of the edge sealant and the laminate dam and a surface of one of the optical layers are at least partially comprised of a hydrophobic material.

3. The optical device of claim 1 , wherein at least one of the one or more sealant gaps at least partially overlaps a corresponding one of the one or more dam gaps along the edge of the optical device.

4. The optical device of claim 1 , wherein at least one of the one or more sealant gaps is concentric with a corresponding one of the one or more dam gaps.

5. the edge sealant includes at least two sealant gaps; The optical device of claim 1 , wherein the stack dam includes at least two dam gaps.

6. The optical device of claim 1 , wherein the plurality of optical layers comprises at least three optical layers.

7. 7. The optical device of claim 6, wherein the at least three optical layers comprise a layer for guiding red light, a layer for guiding green light, and a layer for guiding blue light.

8. The optical device of claim 1 , wherein the edge sealant absorbs ultraviolet radiation.

9. The optical device of claim 1 , wherein at least one optical layer of the plurality of optical layers comprises at least one of an orthogonal pupil expander region, an exit pupil expander region, and an internal grating coupling region.

10. The optical device of claim 1 , wherein the edge sealant prevents light leakage from an interior to an exterior of the optical device in a transverse direction through the edge of the optical device.

11. The optical device of claim 1 , wherein the edge sealant prevents reflection of light into an interior of the optical device.

12. The optical device of claim 1 , wherein the edge sealant has a thickness in the range of about 430 microns to about 500 microns.

13. The optical device of claim 12 , wherein a thickness of the edge sealant between the edge of the optical device and the laminate dam is about 350 microns.

14. The optical device of claim 1 , wherein the stack dam has a width of about 500 microns.

15. An eyepiece comprising the optical device of claim 1 .

16. The optical device of claim 1, wherein one of the one or more sealant gaps has a length along the edge of the optical device that exceeds the length of the corresponding dam gap.

Images