This disclosure relates generally to optics, and in particular to lenses.
Prescription lenses were traditionally fabricated out of glass before transitioning to predominantly plastic lenses. The conventional manufacturing technique for prescription lenses is to form a prescription surface specific to an individual from a plastic blank that has a base curve. This technique works well for fabricating traditional eye glasses, although the thickness and weight of traditional prescription lenses constrain design, in some contexts.
Non-limiting and non-exhaustive embodiments of the invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified.
Embodiments of glass and plastic hybrid lens are described herein. In the following description, numerous specific details are set forth to provide a thorough understanding of the embodiments. One skilled in the relevant art will recognize, however, that the techniques described herein can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring certain aspects.
Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
In some implementations of the disclosure, the term “near-eye” may be defined as including an element that is configured to be placed within 50 mm of an eye of a user while a near-eye device is being utilized. Therefore, a “near-eye optical element” or a “near-eye system” would include one or more elements configured to be placed within 50 mm of the eye of the user.
In aspects of this disclosure, visible light may be defined as having a wavelength range of approximately 380 nm-700 nm. Non-visible light may be defined as light having wavelengths that are outside the visible light range, such as ultraviolet light and infrared light. Infrared light having a wavelength range of approximately 700 nm-1 mm includes near-infrared light. In aspects of this disclosure, near-infrared light may be defined as having a wavelength range of approximately 700 nm-1.4 μm.
In aspects of this disclosure, the term “transparent” may be defined as having greater than 90% transmission of light. In some aspects, the term “transparent” may be defined as a material having greater than 80% transmission of visible light.
Aspects of this disclosure are directed to a lens that includes a glass layer and a plastic layer. Conventional lenses have been either all glass or all plastic for ease of manufacturing. The glass layer may be a pre-formed glass element to provide structural support and mechanical rigidity while the plastic portion reduces the overall weight of the lens. The glass layer may be strengthened glass. The glass layer may have optical or display functions.
Lenses are typically “edged” to form the lens into a lens shape suitable for eyeglasses. However, in a glass lens, edging glass may cause chipping or cracking of the glass. With a glass-plastic lens, edging the glass portion of the lens is also susceptible to chipping, cracking, and separating the glass portion from the plastic portion of the lens. In implementations of the disclosure, an outside boundary of a plastic layer extends past the outside boundary of the glass layer so that the plastic layer can be edged into the lens shape without risking edging the glass layer. A prescription surface may be formed in the plastic layer to provide an ophthalmic lens that focuses light to the retina for a specific user. The rigidity of the glass layer may also allow for adding additional optical layers to the lens while maintaining design tolerances. For example, in a particular context of augmented reality (AR) or virtual reality (VR), a display layer or an eye-tracking layer is bonded to the glass layer of the glass-plastic hybrid lens. These and other embodiments are described in more detail in connection with
Glass layer 120 may be strengthened glass. “Strengthened glass” may be heat strengthened or chemically strengthened. Heat strengthened glass has increased strength as a result of heating glass beyond its softening point and then cooling it down rapidly, whereas chemically strengthened glass has increased strength as a result of post-product chemical process. One example of chemically strengthened glass is an alkali-aluminosilicate glass which gains strength by immersion in a potassium salt bath where larger potassium ions are exchanged. In one example, glass layer 120 includes a soda lime glass.
Plastic layer 130 includes a first plastic side 131 disposed opposite of a second plastic side 132. The first plastic side 131 is bonded to the second glass side 122 of glass layer 120. First plastic side 131 may be “bonded” to second glass side 122 by overmolding a polymer onto glass layer 120, in some implementations. The refractive index of glass layer 120 may have the same index of refraction as the refractive index of plastic layer 130. An outside plastic boundary 133 of plastic layer 130 extends past an outside glass boundary 123 of glass layer 120. Plastic layer 130 extends a width 191 past the outside glass boundary 123 of glass layer 120, in
A prescription surface to focus light to an eye of an individual may be formed in the second plastic side 132. A thickness 139 of the plastic layer 130 through an optical axis 181 of the prescription surface may be 50 microns. The mechanical rigidity of the glass layer 120 may allow for such a shallow thickness 139 of plastic layer 130 in lens 101. In some implementations, thickness 139 may be 100 microns. Thickness 139 may be between 50 microns and 2 mm, depending on prescription requirements.
Plastic layer 230 includes a first plastic side 231 disposed opposite of a second plastic side 232. The first plastic side 231 is bonded to the second glass side 222 of glass layer 220. In the illustrated implementation, first plastic side 231 is bonded to the second glass side 222 by way of a bonding layer 240. Bonding layer 240 may be optically clear adhesive (OCA) or liquid optically clear adhesive (LOCA) cured by UV or thermal, in some implementations. The refractive index of glass layer 220 may have a same index of refraction as the refractive index of plastic layer 230. An outside plastic boundary 233 of plastic layer 230 extends past an outside glass boundary 223 of glass layer 220. Plastic layer 230 extends a width 291 past the outside glass boundary 223 of glass layer 220. Width 291 may be approximately 0.5 mm. Width 291 may be greater than 0.5 mm. Width 291 may be approximately 1 mm. In the particular implementations of
A prescription surface to focus light to an eye of an individual may be formed in the second plastic side 232. A thickness 239 of the plastic layer 230 through an optical axis 281 of the prescription surface may be 50 microns. The mechanical rigidity of the glass layer 220 may allow for such a shallow thickness 239. In some implementations, thickness 239 may be 100 microns. Thickness 239 may be between 50 microns and 2 mm, depending on the required prescription.
In process block 305, a glass layer is disposed onto a mold.
Referring back to
Referring back to process 300 of
In process block 505, a glass layer is bonded to a plastic layer and an outside plastic boundary of the plastic layer extends past an outside glass boundary of the glass layer.
Glass layer 620 may have the attributes described in connection with glass layer 220. Glass layer 620 includes a first glass side 621 and a second glass side 622. Plastic layer 630 includes a first plastic side 631 disposed opposite of a second plastic side 632. Second plastic side 632 may include a base curvature as a starting surface to forming a prescription surface in a subtractive process (e.g. diamond turning the prescription surface). In other implementations, second plastic side 632 already has a prescription surface formed in second plastic side 632, prior to bonding to glass layer 620. While not specifically illustrated, one or more optical layers similar to optical layer 460 may be formed on the second plastic side 632.
Referring back to process 500 of
In some implementations (not illustrated), an eye-tracking layer is bonded to optical element 730A. The eye-tracking layer may include a plurality of in-field light sources (e.g. near-infrared vertical-cavity surface-emitting lasers) for illuminating an eyebox area and an optical combiner for directing near-infrared images to be imaged by eye-tracking camera(s) 704.
As shown in
Example head mounted device 700 may also include supporting hardware incorporated into the frame 702 and/or temple arms 704A and 704B. The hardware of head mounted device 700 may include any of processing logic, wired and/or wireless data interface for sending and receiving data, graphic processors, and one or more memories for storing data and computer-executable instructions. In one example, head mounted device 700 may be configured to receive wired power and/or may be configured to be powered by one or more batteries. In addition, head mounted device 700 may be configured to receive wired and/or wireless data including video data.
Display layer 750A may include one or more other optical elements depending on the design of the head mounted device 700. For example, the display layer 750A may include a waveguide 758 to direct display light 793 generated by an electronic display to the eye of the user. In some implementations, at least a portion of the electronic display is included in the frame 702 of the head mounted device 700. The electronic display may include an LCD, an organic light emitting diode (OLED) display, micro-LED display, pico-projector, or liquid crystal on silicon (LCOS) display for generating the display light 793. In some embodiments, near-eye optical elements 710 may not include a display and may be included in a head mounted device that is not considered a head mounted display.
Optical layer 730A may have a lens curvature for focusing light (e.g., display light 793 and/or scene light 791) to the eye of the user on the eyeward side 709 of the near-eye optical element 710A. In some aspects, the optical layer 730A has a thickness and/or curvature that corresponds to the specifications of a user. In other words, optical layer 730A may be a prescription lens. Thus, the optical layer 730A may, in some examples, may be referred to as an ophthalmic lens. However, in other examples, optical layer 730A may be a non-prescription lens.
Embodiments of the invention may include or be implemented in conjunction with an artificial reality system. Artificial reality is a form of reality that has been adjusted in some manner before presentation to a user, which may include, e.g., a virtual reality (VR), an augmented reality (AR), a mixed reality (MR), a hybrid reality, or some combination and/or derivatives thereof. Artificial reality content may include completely generated content or generated content combined with captured (e.g., real-world) content. The artificial reality content may include video, audio, haptic feedback, or some combination thereof, and any of which may be presented in a single channel or in multiple channels (such as stereo video that produces a three-dimensional effect to the viewer). Additionally, in some embodiments, artificial reality may also be associated with applications, products, accessories, services, or some combination thereof, that are used to, e.g., create content in an artificial reality and/or are otherwise used in (e.g., perform activities in) an artificial reality. The artificial reality system that provides the artificial reality content may be implemented on various platforms, including a head-mounted display (HMD) connected to a host computer system, a standalone HMD, a mobile device or computing system, or any other hardware platform capable of providing artificial reality content to one or more viewers.
The term “processing logic” in this disclosure may include one or more processors, microprocessors, multi-core processors, Application-specific integrated circuits (ASIC), and/or Field Programmable Gate Arrays (FPGAs) to execute operations disclosed herein. In some embodiments, memories (not illustrated) are integrated into the processing logic to store instructions to execute operations and/or store data. Processing logic may also include analog or digital circuitry to perform the operations in accordance with embodiments of the disclosure.
A “memory” or “memories” described in this disclosure may include one or more volatile or non-volatile memory architectures. The “memory” or “memories” may be removable and non-removable media implemented in any method or technology for storage of information such as computer-readable instructions, data structures, program modules, or other data. Example memory technologies may include RAM, ROM, EEPROM, flash memory, CD-ROM, digital versatile disks (DVD), high-definition multimedia/data storage disks, or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information for access by a computing device.
Communication channels may include or be routed through one or more wired or wireless communication utilizing IEEE 802.11 protocols, BlueTooth, SPI (Serial Peripheral Interface), I2C (Inter-Integrated Circuit), USB (Universal Serial Port), CAN (Controller Area Network), cellular data protocols (e.g. 3G, 4G, LTE, 5G), optical communication networks, Internet Service Providers (ISPs), a peer-to-peer network, a Local Area Network (LAN), a Wide Area Network (WAN), a public network (e.g. “the Internet”), a private network, a satellite network, or otherwise.
A computing device may include a desktop computer, a laptop computer, a tablet, a phablet, a smartphone, a feature phone, a server computer, or otherwise. A server computer may be located remotely in a data center or be stored locally.
The processes explained above are described in terms of computer software and hardware. The techniques described may constitute machine-executable instructions embodied within a tangible or non-transitory machine (e.g., computer) readable storage medium, that when executed by a machine will cause the machine to perform the operations described. Additionally, the processes may be embodied within hardware, such as an application specific integrated circuit (“ASIC”) or otherwise.
A tangible non-transitory machine-readable storage medium includes any mechanism that provides (i.e., stores) information in a form accessible by a machine (e.g., a computer, network device, personal digital assistant, manufacturing tool, any device with a set of one or more processors, etc.). For example, a machine-readable storage medium includes recordable/non-recordable media (e.g., read only memory (ROM), random access memory (RAM), magnetic disk storage media, optical storage media, flash memory devices, etc.).
The above description of illustrated embodiments of the invention, including what is described in the Abstract, is not intended to be exhaustive or to limit the invention to the precise forms disclosed. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes, various modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize.
These modifications can be made to the invention in light of the above detailed description. The terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification. Rather, the scope of the invention is to be determined entirely by the following claims, which are to be construed in accordance with established doctrines of claim interpretation.