3D printing to form an optical lens with integrated electronics

Abstract

In various embodiments, a device includes an optical substrate and one or more electrical components coupled to the optical substrate. The device includes one or more polymer materials additively printed around the one or more electrical components to at least in part encapsulate the one or more electrical components and form at least a portion of an optical lens.

Description

3D PRINTING TO FORM AN OPTICAL LENS WITH INTEGRATED ELECTRONICS BACKGROUND OF THE INVENTION

[0001] Integrating electronics into an optical lens may provide many benefits for users. For example, augmented reality presents additional information about the environment for users. An optical lens such as glasses that have integrated electronics is one way to present augmented reality. However, lenses produced by conventional techniques are typically thick and / or suffer from distortion such as waviness. Additionally, conventional techniques tend to exert large mechanical forces on the lens during the manufacturing process, which may cause damage to the electronics. Thus, there is a need for an improved lens and lens manufacturing process.SUMMARY OF THE INVENTION

[0002] According to the present invention there is provided a device comprising an optical substrate; one or more electrical components coupled to the optical substrate; and one or more polymer materials additively printed around the one or more electrical components to at least in part encapsulate the one or more electrical components and form at least a portion of an optical lens.

[0003] Optionally, the one or more electrical components include an illumination device.

[0004] Optionally the one or more electrical components include a light emitting diode (LED).

[0005] Optionally the one or more electrical components include an imaging device.

[0006] Optionally the one or more electrical components include a camera.

[0007] Optionally the device further comprises an additive coating.

[0008] Optionally the optical lens is formed using the one or more polymer materials additively printed based at least on a pre-determined shape.

[0009] Optionally, a thickness of at least a portion of the optical lens is less than or equal to 50pm.

[0010] Optionally a thickness of a layer formed by the one or more polymer materials is less than or equal to 50pm.

[0011] Optionally the optical lens has reduced waviness compared with an optical lens produced by other means.

[0012] Optionally, the optical lens has an aspect ratio of at least 10.

[0013] According to the present invention there is further provided a devicecomprising an optical substrate; an illumination device coupled to the optical substrate; an imaging device coupled to the optical substrate; and one or more polymer materials additively printed around the illumination device and the imaging device to at least in part encapsulate the illumination device and the imaging device and form at least a portion of an optical lens.

[0014] According to the present invention there is yet further provided a method of manufacture, comprising providing an optical substrate: positioning one or more electrical components coupled to the optical substrate; and forming at least a portion of an optical lens including by additively printing one or more polymer materials around the one or more electrical components to encapsulate, at least in part, the one or more electrical components.

[0015] Optionally the method further comprises, subsequent to the positioning of the one or more electrical components coupled to the optical substrate, adding an adhesion promoter to promote a bond between the optical substrate and the one or more electrical components.

[0016] Optionally, additively printing the one or more polymer materials around the one or more electrical components includes depositing droplets of the one or more polymer materials on top of the one or more electrical components and a region without the one or more electrical components.

[0017] Optionally, additively printing the one or more polymer materials around the one or more electrical components includes: depositing droplets of the one or more polymer materials over regions without the one or more electrical components; and not depositing droplets of the one or more polymer materials over the one or more electrical components.

[0018] Optionally a thickness of at least one layer of droplets of the one or more polymer materials is less than or equal to 10pm.

[0019] Optionally a thickness of at least one layer of droplets of the one or more polymer materials is less than or equal to 5 pm.

[0020] Optionally the method further comprises attaching one or more components to the optical lens following the formation of the at least a portion of the optical lens.

[0021] Optionally the method further comprises applying a coating to the optical lens.BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Various embodiments of the invention are disclosed in the following detailed description and the accompanying drawings.

[0023] FIG. 1 is a block diagram illustrating an embodiment of an optical lens withintegrated electronics.

[0024] FIG. 2 is a flow diagram illustrating an embodiment of a process for manufacturing an optical lens with integrated electronics.

[0025] FIG. 3A shows the system after electronics have been positioned over and bonded to a substrate.

[0026] FIG. 3B shows the system following electronics bonding and 3D printing an encapsulation.

[0027] FIG. 3C shows the system following printing the lens and an optional coating.

[0028] FIG. 4A is a top-down view of an optical lens according to an embodiment of the present disclosure.

[0029] FIG. 4B is a perspective view of an optical lens according to an embodiment of the present disclosure.

[0030] FIG. 5 is a top-down view of an optical lens according to an embodiment of the present disclosure.DETAILED DESCRIPTION

[0031] The invention can be implemented in numerous ways, including as a process; an apparatus; a system; a composition of matter; a computer program product embodied on a computer readable storage medium; and / or a processor, such as a processor configured to execute instructions stored on and / or provided by a memory coupled to the processor. In this specification, these implementations, or any other form that the invention may take, may be referred to as techniques. In general, the order of the steps of disclosed processes may be altered within the scope of the invention. Unless stated otherwise, a component such as a processor or a memory described as being configured to perform a task may be implemented as a general component that is temporarily configured to perform the task at a given time or a specific component that is manufactured to perform the task. As used herein, the term ‘processor' refers to one or more devices, circuits, and / or processing cores configured to process data, such as computer program instructions.

[0032] A detailed description of one or more embodiments of the invention is provided below along with accompanying figures that illustrate the principles of the invention. The invention is described in connection with such embodiments, but the invention is not limited to any embodiment. The scope of the invention is limited only by the claims and the invention encompasses numerous alternatives, modifications, and equivalents. Numerous specific details are set forth in the following description in order to provide athorough understanding of the invention. These details are provided for the purpose of example and the invention may be practiced according to the claims without some or all of these specific details. For the purpose of clarity, technical material that is known in the technical fields related to the invention has not been described in detail so that the invention is not unnecessarily obscured.

[0033] Integrating electronics into an optical system has long been a challenge for the photonics industry. A typical process is using a polymer substrate and laminating that to the final optics (lens / glass). However, this process is not suitable for augmented reality (AR) systems because of thickness and waviness. Resulting lenses tend to be thick (e.g., greater than 150pm) because there are several layers in the optical stack. Soft layer lamination tends to be complex and lacks flexibility and may also cause waviness.

[0034] Conventional techniques for lens production include molding, casting, and diamond turning. For example, one conventional technique to produce a lens with integrated electronics is casting. However, casting typically involves introducing a substantial volume of material into a mold, which may displace electronics. Casting tends to be less accurate and precise than the disclosed techniques.

[0035] In some conventional systems, light emitting diodes (LEDs) are bonded to a polymer and form a first stack in the architecture. Eye tracking functionality is provided by a second stack (separate from the first stack) that is laminated to the glass as part of the model and system level integration. An Optically Clear Adhesive (OCA) is applied to laminate the plastic lens to the glass. The adhesive layer provides a soft boundary between the glass and plastic lens, which reduces the w arp on the glass and improves the CTE mismatch by providing compliance between the layers. Using OCA helps reduce warp, but the process to create a one piece stack is disrupted due to a secondary process of laminating the plastic lens to the glass. Manufacturing a thin lens for lamination is difficult and does not deliver the same optical performance as the techniques disclosed herein that produce 3D printed lens.

[0036] Other conventional techniques create a single stack, also referred to as a monolithic assembly. However, those conventional techniques typically have associated challenges. For example, after printing the lens, the material shrinks as it cures and will often cause the glass layer to warp. Also, due to the Coefficient Thermal Expansion (CTE) difference betw een the glass and plastic material, the plastic lens may delaminate from the glass.

[0037] The disclosed techniques include 3D printing to produce a lens with integrated electronics. In various embodiments, the disclosed techniques produce a monolithic lensassembly in which electrical components (e.g., LEDs or other electronics) are combined, and 3D printing is applied to produce a lens with the embedded components. The resulting lens has high optical quality and performance, reduced thickness, and does not suffer from some of the issues that result from alternative production techniques as further described herein.

[0038] In various embodiments, pre-lamination is performed while in other embodiments pre-lamination is not performed. For example, in various embodiments, printing is directly applied onto a pre-laminated glass / OCA substrate. Pre-lamination includes laminating a glass substrate with an OCA. After the glass is laminated with a predetermined volume of OCA (50pm to 100pm), it can be inserted into an optical 3D printer where the lens can be directly printed on top of the adhesive. The lens material is directly deposited on top of the adhesive and permanently fixed to the glass. After printing of the lens the optical assembly can be post cured in an oven or UV light source.

[0039] FIG. 1 is a block diagram illustrating an embodiment of an optical lens with integrated electronics. The system (sometimes also referred to as a device) includes an optical substrate 120; one or more electrical components 110, 112, and 114, and a lens 140. The electrical components are encapsulated and integrated with the lens 140 using a manufacturing process further described with respect to FIG. 2. Benefits of the optical lens include reduced thickness, improved performance, and greater customizability, as further described herein.

[0040] In various embodiments, the substrate 120 may be made of a variety of materials such as glass (e g., a chemically strengthened glass such as alkali-aluminosilicate glass), plastic (e.g., polycarbonate), or any other material suitable for receiving electronics and having electronics bonded to it.

[0041] The system includes one or more electrical components 110, 112, and 114 coupled to the optical substrate. The one or more electrical components may include an illumination device, an imaging device, a camera, chip, or any other electronic device. For example, components 110, 112 are for illumination, e.g., LEDs, and component 114 is for imaging, e.g., a camera or processor. Wires for providing electrical connections between components may be nanowires, e.g.. a 5- 10pm diameter wire. In various embodiments, the wire could be an Indium Titanium Dioxide (ITO) trace or any other suitable material / structure. An example of wire traces are show n in FIGS. 4A-5.

[0042] LEDs are typically provided in a carrier film that includes the LEDs and wires to connect to other electronics. Conventionally, lamination is used to form a lens assembly that includes the LEDs. Lamination produces a multi-layer system in which a first side is theLED and the other side is an optical lens. However, lamination tends to cause waviness, which manifests in the optical lens and reduces lens quality. In addition, it is challenging to control proper index matching on films and adhesives involved in conventional techniques, and they add to losses in the system. By contrast, the disclosed techniques include printing the optical lens, which does not involve lamination and therefore avoids waviness. In other words, an optical lens is produced without layers, resulting in an optical lens with improved quality and performance.

[0043] The system includes a lens 140. One or more polymer materials may be additively printed around the one or more electrical components 110, 112, and 114 to at least in part encapsulate the one or more electrical components and form at least a portion of a lens 140 as further described herein. In various embodiments, components 110 and 112 are on the order of 100pm and lens section 140 is on the order of 50pm. The center thickness may be less than 100pm if the components 110 and 112 are relatively close to the edge.

[0044] Although not shown here, in various embodiments, the system includes an additive coating such as an anti-reflective coating.

[0045] FIG. 2 is a flow diagram illustrating an embodiment of a process for manufacturing an optical lens with integrated electronics. The process may be performed by a 3D printer such as the printer 300 shown in FIG. 3B. The process may be performed to manufacture a device such as the one shown in FIGS. 1, 3 A, 3B, 3C, 4A, 4B. and 5.

[0046] The process begins by providing an optical substrate (200). The substrate is laid down. As further described with respect to FIG. 1 , any suitable material to which electronics can be bonded and lens material deposited on may be used. The substrate may be prelaminated.

[0047] The process includes positioning one or more electrical components coupled to the optical substrate (202). The one or more electrical components 114 may be positioned on and then coupled to the substrate via bonding as follows.

[0048] In various embodiments, subsequent to the positioning of the one or more electrical components coupled to the optical substrate, the process includes adding an adhesion promoter to promote a bond between the optical substrate and the one or more electrical components. For example, an adhesion promoter is added to the substrate to form a direct bond. Any adhesion promoter that allow s for the component to be positioned in place without moving during subsequent processes (e.g., printing) may be used. By way of nonlimiting example, an adhesion promoter is OCA. In various embodiments, the adhesion promoter includes an adhesive coating (with a thickness of <200-300 nm) to enable theadhesion of 3D printed material to the substrate or electrical components. The coating can be applied via spin coating or other coating processes.

[0049] In various embodiments, the one or more electrical components are manually placed. For example, traces are positioned on a plate or fixture, and the fixture is passed into a printer to print a lens on top / over the traces as further described herein. Alternatively or in combination, the one or more electrical components may be printed or deposited. For example, metal components such as wire may be printed. Example components are described in FIG. 1.

[0050] The process includes providing one or more polymer materials additively printed around the one or more electrical components to at least in part encapsulate the one or more electrical components and form at least a portion of an optical lens (204). In various embodiments, the one or more polymer materials are dispensed in liquid form as droplets (sometimes called liquid ink). That is, micro droplets of a bottle of ink are jetted into a desired position, e.g., pixel by pixel like an inkjet. Drops are stacked and cured, similar to typical 3D printing. A series of 2D images is stacked to create the final 3D product. However, each layer is thinner than what is conventional for 3D printing, e.g., here each layer is 5 to 10pm thick. That is, the thickness of a layer formed by one or more polymer materials is less than or equal to 5 pm (or less than or equal to 10pm). Each layer is pinned, meaning the layer is partially UV-cured. When the optical lens (or a portion of the optical lens as further described herein) is completed, the assembly is fully UV-cured to fully cross-link.

[0051] The size of the droplet, temperature, and flow rate may be controlled to form a desired optical lens. When a (liquid) droplet is dispensed, the droplet cross links with adjacent droplets / components, meaning they attach to the surrounding surfaces. In the examples described herein, one adjacent surface is an electrical component such as an LED and another adjacent surface is another droplet. In other words, there is at least some flow to the liquid droplet so that it will at least partially fill in gaps on the substrate.

[0052] In various embodiments, printing includes printing on top of the one or more electrical components. That is. additively printing polymer material(s) around the electrical component(s) includes depositing droplets of the polymer material(s) (both) on top of the electrical component(s) and a region without the electrical component(s). For example, the components are ignored or treated as if they are not present and droplets are deposited in the same manner in regions containing components and regions that do not contain components. Experiments show that the droplets fill out the gaps and comers so that the resulting lens does not have any bumps and does not suffer from any performance issues. This technique may besuitable where the size of the components are small (e.g., no greater than 100pm).

[0053] In various embodiments, printing around the electrical components assumes that the components are in place and the printing omits those sections. That is, additively printing the polymer material(s) around the electrical component(s) includes depositing droplets of the polymer material(s) over regions without the electrical component(s), and not depositing droplets of the polymer material(s) over the electrical component(s). The layout / expected locations of electrical components may be stored in a "recipe.” In other words, when printing a layer, an area is skipped if there is an electrical component there. This is sometimes referred to as “printing with holes” because the holes (corresponding to electrical components) are skipped over when printing.

[0054] In various embodiments, a top surface of an electrical component is left exposed and not printed over. For example, a camera lens typically needs a clearance and / or nothing covering the lens (to avoid distortion), so printing would skip over the lens of the camera. For example, one or more components is attached to the optical lens (e.g., a camera) following the formation of at least a portion of the optical lens so that the camera sits on top of the printed portion and the lens of the camera is not covered by the polymer material(s).

[0055] In various embodiments, one or more coatings (e.g., an anti-reflective coating) are applied to the optical lens.

[0056] One of the benefits of 3D printing is that a variety of materials can be used to form the optical lens, including using more than one type of material in a particular optical lens. For example, a softer (e.g., a lower modular) material can be used to embed and anchor components, followed by printing with another material to complete the optical lens. The polymer material is made of: acrylic or optical accolade, e.g., urethane or any material that can be jetted.

[0057] In various embodiments, the process may be paused at any point and resumed. For example, the optical lens can be partially formed, then cured. Later, the optical lens may be completed, e.g., to create a custom lens. That is, custom lenses may all start with a same base model and then they are finished differently to provide the customization.

[0058] FIG. 3 A shows the system after electronics 310 have been positioned over and bonded to a substrate 120. The system includes one or more electronics 310 coupled to substrate 120 via an adhesive or structure 312.

[0059] FIG. 3B shows the system following electronics bonding and 3D printing an encapsulation 130. In this example, encapsulation 130 has been formed using the disclosed techniques. For example, print 300 deposits micro droplets of a polymer to form theencapsulation 130 as further described herein.

[0060] FIG. 3C shows the system following printing the lens (which may have a prescription) 140 and an optional coating 150. For example, coating 350 may be an anti- reflective coating or other coating.

[0061] FIG. 4 A is a top-down view of an optical lens according to an embodiment of the present disclosure.

[0062] FIG. 4B is a perspective view of an optical lens according to an embodiment of the present disclosure. In this example, LEDs are located at 400 and 402. Wire traces 404 are located outside the lens in this example. In various embodiments, the wire is connected to a connector inside a frame to connect the stack to the PCBA.

[0063] FIG. 5 is a top-down view of an optical lens according to an embodiment of the present disclosure. Wire traces 500 are located throughout the lens as indicated.

[0064] The disclosed techniques have various features and benefits compared with conventional techniques including:• Reduced waviness on optical stack• Reduced thickness and weight, e.g., allows for lens center thickness of around 50pm vs. a minimum of 150pm if another lens manufacturing process is used o Conventional techniques are typically unable to obtain a thin center section with integrated electronics because too many forces are imparted on the lens so that the electronics are typically damaged in the process. By contrast, in various embodiments, the thickness of at least a portion of the optical lens (e.g., a center portion) is less than or equal to 50pm.• High optical quality and performance. For example, due to the simplicity and high accuracy of the 3D printing process, the resulting lenses have better cosmetic quality and lower yield compared with lenses produced by other techniques.• Reduced cost and complexity' of the manufacturing process• Better control of the manufacturing process, e.g., increased precision / accuracy• Enables net shape and net prescription fabrication o An optical lens can be printed based on a customized prescription. The lens may also be adapted to an eye / frame shape, or other features of a user. In other words, the optical lens is formed using one or more polymer materials additively printed based at least on a pre-determined shape. Edging, which is ty pically required for conventional techniques, does not need to be performed.• Eliminates mechanical forces such as diamond turning, which may damage electronics• Enables on demand / in-flight customization• Permits / supports adding of Beam shaping to the electronics o This may be beneficial when the optical lens includes a camera. Beam shaping refers to control over a shape or modifications on top of LEDs or cameras such as adding a second lens on top.• Builds a homogeneous material stack instead of a multi-layer with mismatched CTEs o For example, plastic grows more than glass at high temperatures. The disclosed techniques allow for fine tuning of CTE issues during printing, which improves the mechanical integrity of the assembly.• Potential for greater range of material selection• Achieves higher quality surface material: e.g.. less diffraction due to gaps o The resulting surface is smoother than optical lenses created using conventional techniques.• Supports in-situ hard coating (e.g., prior to anti -reflective coating)• Capable of achieving a high aspect ratio (e.g.. at least 10; by contrast molding techniques typically can only achieve an aspect ratio of less than 5) o Aspect ratio refers to a ratio of the length of a lens to the center thickness of the lens o Special lenses such as a large lens can be printed, which is challenging using conventional techniques such as molding, casting, or diamond turning.

[0065] The disclosed techniques include using glass / W G substrate for bonding electronics (such as one or more LEDs or cameras) and 3D printing the lens on top of the substrate to both encapsulate the electronics and create a VIDl / Rxl lens. Benefits of the disclosed techniques include: reducing thickness, simplifying the manufacturing process, reducing / eliminating waviness (e.g., distortion or pupil swim) due to soft layer lamination, improving flexibility to create any lens curvature, among other things. Experiments show that the disclosed techniques can be applied to print VCSELs bonded on a glass for an ET system.

[0066] The disclosed techniques find application in a variety of settings. For example, infield illumination encapsulation like the one described herein is important for eye tracking devices. As another example, the disclosed techniques may be used for integrating ET imaging cameras, which in turn benefits AR systems, e.g., by improving the form factor ofthe AR system.

[0067] Although the foregoing embodiments have been described in some detail for purposes of clarity of understanding, the invention is not limited to the details provided. There are many alternative ways of implementing the invention. The disclosed embodiments are illustrative and not restrictive.

Claims

CLAIMS1. A device, comprising: an optical substrate; one or more electrical components coupled to the optical substrate; and one or more polymer materials additively printed around the one or more electrical components to at least in part encapsulate the one or more electrical components and form at least a portion of an optical lens.

2. The device of claim 1, wherein the one or more electrical components include an illumination device, wherein the illumination device is optionally a light emitting diode (LED).

3. The device of claim 1, wherein the one or more electrical components include an imaging device, wherein the imaging device is optionally a camera.

4. The device of claim 1, further comprising an additive coating.

5. The device of claim 1, wherein the optical lens is formed using the one or more polymer materials additively printed based at least on a pre-determined shape.

6. The device of claim 1, wherein a thickness of at least a portion of the optical lens is less than or equal to 50pm.

7. The device of claim 1, wherein a thickness of a layer formed by the one or more polymer materials is less than or equal to 50 pm.

8. The device of claim 1, wherein the optical lens has reduced waviness compared with an optical lens produced by other means; and / or wherein the optical lens has an aspect ratio of at least 10.

9. A device, comprising: an optical substrate; an illumination device coupled to the optical substrate; an imaging device coupled to the optical substrate; and one or more polymer materials additively printed around the illumination device and the imaging device to at least in part encapsulate the illumination device and the imaging device and form at least a portion of an optical lens.

10. A method of manufacture, comprising: providing an optical substrate; positioning one or more electrical components coupled to the optical substrate; and forming at least a portion of an optical lens including by additively printing one ormore polymer materials around the one or more electrical components to encapsulate, at least in part, the one or more electrical components.

11. The method of manufacture of claim 10, further comprising, subsequent to the positioning of the one or more electrical components coupled to the optical substrate: adding an adhesion promoter to promote a bond between the optical substrate and the one or more electrical components.

12. The method of manufacture of claim 10. wherein the additively printing the one or more polymer materials around the one or more electrical components includes depositing droplets of the one or more polymer materials on top of the one or more electrical components and a region without the one or more electrical components; or wherein additively printing the one or more polymer materials around the one or more electrical components includes: depositing droplets of the one or more polymer materials over regions without the one or more electrical components; and not depositing droplets of the one or more polymer materials over the one or more electrical components.

13. The method of manufacture of claim 10, wherein a thickness of at least one layer of droplets of the one or more polymer materials is less than or equal to 10pm.

14. The method of manufacture of claim 10, wherein a thickness of at least one layer of droplets of the one or more polymer materials is less than or equal to 5pm.

15. The method of manufacture of claim 10, further comprising: attaching one or more components to the optical lens following the formation of the at least a portion of the optical lens; and / or applying a coating to the optical lens.

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