Concave lens

Abstract

A pair of eyeglasses may include one or more adjustable lenses. Each adjustable lens may include a switchable liquid crystal diffusion sheet or an adjustable microlens array. The switchable diffusion sheet may have a clear concave region surrounded by a diffusion peripheral region that reduces contrast in the user's peripheral vision to help slow myopia progression. The switchable diffusion sheet may include a liquid crystal material interposed between a blanket common electrode and an array of finger electrodes or between a first set of arrays of orthogonal electrodes and a second set of arrays of orthogonal electrodes. The eyewear may include a gaze tracking sensor that tracks a gaze of a user. The clear concave region is displaceable to maintain alignment with the user's gaze. In a microlens array arrangement, microlenses in a gaze region may pass light unaltered, while microlenses in a peripheral region may refract and refocus light in front of the retina to assist in slowing myopia progression.

Description

[0001] This application claims the benefit of priority to U.S. Patent Application No. 18 / 985,573, filed on December 18, 2024, and U.S. Provisional Patent Application No. 63 / 626,894, filed on January 30, 2024, the entire disclosures of which are hereby incorporated by reference in their entireties. BACKGROUND OF THE INVENTION

[0002] The present invention generally relates to optical systems and, more particularly, to devices having concave lenses.

[0003] Glasses may include an optical system, such as a lens. For example, glasses (such as a pair of glasses) may include lenses that allow a user to observe the surrounding environment.

[0004] Designing devices such as these can be challenging. Without proper attention, the optical systems in these devices may not be able to accommodate different visual conditions and may not perform satisfactorily. SUMMARY OF THE INVENTION

[0005] Glasses may be worn by a user and may include one or more adjustable lenses, each adjustable lens being aligned with a corresponding eye in the user's eyes. For example, a first adjustable lens may be aligned with the user's left eye, and a second adjustable lens may be aligned with the user's right eye. Each adjustable lens may include a switchable diffuser formed of a liquid crystal material or may include an adjustable microlens array. The switchable diffuser may have a clear concave region that is aligned with the user's gaze and is surrounded by a diffused (e.g., contrast-reduced) peripheral region. In the microlens array, the microlenses in the gaze region may keep the light unchanged, while the microlenses in the peripheral region may be adjusted to refract the light and refocus it in front of the retina. Reducing contrast and / or introducing myopic defocus in the user's peripheral vision may help slow down myopia progression.

[0006] Each of the first adjustable lens and the second adjustable lens may include one or more liquid crystal cells or other voltage-modulated optical materials. Each liquid crystal cell may include a layer of liquid crystal material interposed between transparent substrates. A control circuit may apply control signals to an electrode array in the liquid crystal cell to adjust the phase distribution of the liquid crystal material. The liquid crystal material may be interposed between a blanket common electrode and a finger electrode array, or in a passive matrix addressing scheme the liquid crystal material may be sandwiched between a first set of orthogonal electrode arrays and a second set of orthogonal electrode arrays. Arrangements may also be used in which the liquid crystal is interposed between a blanket common electrode and an array of pixelated electrodes (e.g., rectangular electrodes, hexagonal electrodes, disc electrodes, and / or other pixelated electrodes). The liquid crystal material may preferentially diffuse and / or refocus light in a particular direction (such as a radial direction or a tangential direction) to help focus peripheral light in front of the retina. If desired, the liquid crystal material may exhibit high dispersibility to diffuse and / or refocus blue light more than red light in the peripheral region.

[0007] Liquid crystal materials are used herein as an example of electro-modulated optical materials. Other electro-modulated optical materials may be used to replace the liquid crystals described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a diagram of an exemplary system including glasses with a concave lens according to an embodiment.

[0009] Figure 2 is a perspective view of a concave lens system according to an embodiment.

[0010] Figure 3 is a side view of an exemplary liquid crystal cell that can be used to form a concave lens according to an embodiment.

[0011] Figure 4 is a side view of an exemplary liquid crystal module having a first liquid crystal layer and a second liquid crystal layer with anti-parallel liquid crystal alignment orientations according to an embodiment.

[0012] Figure 5 is a perspective view of an exemplary stack of liquid crystal cells with different electrode orientations according to an embodiment.

[0013] Figure 6 is a graph showing an exemplary voltage distribution that can be applied across a liquid crystal cell to produce a clear concave region and a diffused peripheral region according to an embodiment.

[0014] Figure 7 is a perspective view of an exemplary liquid crystal cell having a passive matrix array according to an embodiment.

[0015] Figure 8is a graph showing an exemplary voltage distribution that can be applied to a passive matrix array of liquid crystal cells according to an embodiment to produce a clear concave region and a diffused peripheral region.

[0016] Figure 9 is a side view of an exemplary polymer dispersed liquid crystal cell that can be used to form a concave lens according to an embodiment.

[0017] Figure 10 is a side view of an exemplary adjustable microlens array that can be used to form a concave lens according to an embodiment.

[0018] Figure 11 is according to an embodiment Figure 10 side view of a microlens array of, which shows how the clear concave region can be shifted to different regions of the microlens array to maintain alignment with the fixation position. Detailed Description

[0019] Figure 1 An exemplary system is shown in, the exemplary system having a device with one or more electro - adjustable optical elements. System 10 can include a head - mounted device, such as glasses 14 (sometimes referred to as glasses 14). Device 14 can include one or more optical systems, such as an adjustable lens assembly 22 mounted in a support structure, such as support structure 12. Structure 12 can have the shape of a pair of glasses (e.g., having an independent support frame or a single common support frame), can have the shape of goggles, can form a housing having the shape of a helmet, or can have other configurations that help mount and secure the components of glasses 14 on a user's head.

[0020] The adjustable lens assembly 22 can form a lens that allows an observer (e.g., an observer with eyes 16) to view external objects (such as object 18) in the surrounding environment. Glasses 14 can include one or more adjustable lens assemblies 22, each adjustable lens assembly being aligned with a corresponding eye in the user's eyes 16. For example, the lens assembly 22 can include a left lens 22 aligned with the observer's left eye and can include a right lens 22 aligned with the observer's right eye. However, this is merely exemplary. If desired, glasses 14 can include an adjustable lens assembly 22 for a single eye.

[0021] Axial eye elongation has been shown to be one of the primary mechanisms of myopia progression in a user. The adjustable lens 22 may be configured to modify the light reaching the eye 16 to slow or stop axial eye elongation and thereby slow or stop myopia progression. Specifically, the adjustable lens 22 may include an electro-optically modulated material (such as a liquid crystal material) that diffuses light in the user's peripheral vision while maintaining a clear concave region aligned with the user's fixation. In another arrangement, an adjustable microlens array may be used to introduce myopic defocus at the peripheral retina while keeping the concave fixation region unchanged. If desired, the diffusion profile and / or defocus amount may decrease gradually from the peripheral region to the concave region.

[0022] If desired, the lens 22 may include one or more lenses for correcting visual defects. For example, the eye 16 may have a vision defect such as myopia, hyperopia, presbyopia, astigmatism, higher order aberrations, and / or other vision defects. A corrective lens (such as the lens 22) may be configured to correct these vision defects. The lens 22 may be adjustable to accommodate users with different vision defects and / or to accommodate different focal length ranges. For example, the lens 22 may have a first set of optical characteristics for a first user with a first prescription and a second set of optical characteristics for a second user with a second prescription. If desired, the lens 22 for visual correction may be combined or stacked with the lens 22 that diffuses or refocuses light in the user's peripheral vision to slow myopia progression. The glasses 14 may be used solely for vision correction (e.g., the glasses 14 may be a pair of frame glasses), or the glasses 14 may include a display for presenting virtual reality or augmented reality content (e.g., the glasses 14 may be a head-mounted display). In a virtual reality or augmented reality system, the adjustable lens assembly 22 may be used to move content between focal planes from the perspective of the user. The arrangement in which the glasses 14 are frame glasses that do not include a display is sometimes described herein as an illustrative example. If desired, the glasses 14 may include a tint layer in each lens 22 that reduces the brightness of ambient light reaching the user's eyes (e.g., the glasses 14 may be sunglasses for outdoor use if desired).

[0023] The glasses 14 may include a control circuit 26. The control circuit 26 may include a processing circuit such as a microprocessor, digital signal processor, microcontroller, baseband processor, image processor, application specific integrated circuit with a processing circuit, and / or other processing circuits, and may include random access memory, read only memory, flash memory, hard disk memory, and / or other memory (e.g., a non-transitory storage medium for storing computer instructions for software to be run on the control circuit 26).

[0024] If desired, the control circuit 26 may include one or more energy storage devices, such as one or more batteries and capacitors. The energy storage devices in the glasses 14 may be charged via a wired connection, or if desired, the glasses 14 may use wirelessly received power (e.g., inductive wireless power transfer, capacitive wireless power transfer, and / or other wireless power transfer configurations) to charge the energy storage devices.

[0025] The glasses 14 may include input / output circuitry, such as eye state sensors, a rangefinder configured to measure the distance to an external object 18, touch sensors, buttons, a microphone for collecting voice input and other inputs, sensors, and other devices for collecting inputs (e.g., user input from the observer 16), and may include light-emitting diodes, a display, a speaker, and other devices for providing outputs (e.g., outputs for the observer 16). If desired, the glasses 14 may include wireless circuitry and / or other circuitry that supports communication with a computer or other external device. The glasses 14 may include one or more sensors for collecting inputs during use of the glasses 14. The sensors in the glasses 14 may include an accelerometer, a compass, an ambient light sensor or other light detector, a proximity sensor, a scanning laser system, and other sensors for collecting inputs during use of the glasses 14.

[0026] The gaze tracking system 24 may be used to track the user's eye 16. For example, the gaze tracking system 24 may include one or more digital image sensors, a lidar (light detection and ranging) sensor, a light-emitting diode, a light sensor, an ultrasonic sensor, or other suitable sensors for tracking the position of the user's eye. For example, the gaze tracking system 24 may be used by the control circuit 26 to collect images of the observer's pupil and other parts of the eye. The position of the observer's pupil and the position of the observer's pupil relative to the specular reflection from a light source and the rest of the observer's eye may be used to determine the position of the center of the observer's eye (i.e., the center of the user's pupil) and the direction of the observer's eye line of sight (gaze direction). If desired, the gaze tracking system 24 may use a three-dimensional model of the eye to assist in tracking the gaze direction. In some arrangements, the glasses 14 may include a wavefront sensor that measures the aberration of the user's eye. The control circuit 26 may then adjust the optical characteristics of the lens assembly 22 to correct for the user-specific aberration detected by the wavefront sensor. Arrangements may also be used in which the glasses 14 include a sensor for measuring the axial elongation of the eye (e.g., an ultrasonic sensor, an optical coherence tomography-based sensor, and / or any other suitable sensor configured to measure the length of the eyeball).

[0027] The control circuit 26 can also control the operation of optical elements such as the adjustable lens assembly 22. The adjustable lens assembly 22, sometimes referred to as an adjustable lens, concave lens, adjustable lens system, adjustable optical system, adjustable lens device, tunable lens, fluid-filled variable lens, etc., can include electro-adjustable materials such as liquid crystal materials, volume Bragg gratings, adjustable microlenses, or other electro-modulated materials that can be adjusted to produce a customized lens. In a diffuser sheet arrangement, each of the components 22 can include an electrode array that applies an electric field to a portion of a layer of liquid crystal material or other voltage-modulated optical material having an electro-adjustable refractive index (sometimes referred to as adjustable lens power or adjustable phase distribution). By adjusting the voltage of the signal applied to the electrodes, the refractive index distribution of the component 22 can be dynamically adjusted. For example, the control circuit 26 can apply an appropriate voltage distribution across the lens 22 to create a clear concave region aligned with the user's gaze and a diffused peripheral region outside of the clear concave region (e.g., based on information from the gaze tracking sensor 24). By diffusing light in the user's peripheral vision, the lens 22 can be configured to slow the progression of the user's myopia. In a microlens array arrangement, the control circuit 26 can adjust the microlenses in the user's peripheral vision to refocus (e.g., refract) light to a point in front of the retina, while the microlenses in the gaze region can transmit light unchanged. This type of myopic defocus is another mechanism that can help slow the growth of myopia.

[0028] If desired, the liquid crystal material of the lens 22 can be configured to refract light in a preferred direction (such as a radial or tangential direction), depending on which direction is more likely to focus the light in front of the retina. By preferentially refracting light in the direction that focuses the light in front of the retina, the eye can interpret this as a signal to stop growing, which can help slow the progression of myopia. However, this is merely illustrative. If desired, the liquid crystal material of the lens 22 can be configured to refract light in all different orientations without preferring any one particular orientation.

[0029] In some arrangements, the liquid crystal material of the lens 22 can be a highly dispersive liquid crystal material that exhibits differential refraction and / or diffuses different spectral bands by different amounts. For example, the liquid crystal material of the lens 22 can diffuse or refract blue light more than red light to help slow myopia progression. Specifically, focusing blue light can be a signal that the eye needs to grow. By diffusing blue light more than red light in the user's peripheral vision, the lens 22 can signal to the eye to stop growing. For example, a polymer dispersed liquid crystal material with smaller liquid crystal droplets (e.g., closer to the blue wavelength than the red wavelength) can exhibit greater diffusion for blue light than for red light. Thus, this type of material can be used to help diffuse or refocus blue light in the user's peripheral vision and slow myopia progression while still allowing the user to see focused red light in the user's peripheral vision. For a person interacting with a user wearing the glasses 14, this type of arrangement may be less visually distracting. However, this is merely illustrative. If desired, the lens 22 may not exhibit high dispersivity, and blue and red light in the user's peripheral vision can be equally diffused to help retard myopia progression. If desired, an arrangement can also be used in which the lens 22 diffuses or refracts red light more than blue light.

[0030] If desired, the control circuit 26 can also adjust the lens 22 based on information from one or more sensors such as the sensor 20. The sensor 20 can be a visible light camera, an infrared camera, a depth sensor, an ambient light sensor, a position sensor, or other suitable sensors. The sensor 20 can provide information that can be used to change the operating mode of the lens 22. Specifically, the lens 22 can operate in a first mode and a second mode. In the first mode, the lens 22 is completely clear from edge to edge (e.g., without any diffused or otherwise altered regions). In the second mode, most of the lens 22 diffuses or refocuses light while a small concave region aligned with the user's gaze remains clear. The first mode (where the lens 22 is completely clear) can be useful when the user is outdoors (and thus less affected by myopia progression), when the user is talking to someone (and thus desires an appearance more suitable for conversation), and / or when the user is looking at a distant object (as opposed to looking closely). The second mode (where the peripheral region of the lens 22 diffuses or refocuses light while the gaze region of the lens 22 remains clear) can be useful when the user is looking closely at an object. The control circuit 26 can monitor the triggering conditions of the sensor 20 (e.g., whether the user is outdoors, how far the user's eyes are focused, whether the user is talking to someone, etc.) to indicate whether to operate the lens 22 in the first mode or the second mode.

[0031] If desired, the control circuit 26 can monitor a sensor, such as sensor 20, to determine how much time the user typically spends viewing near objects and how much time the user typically spends viewing far objects for comparison. As another example, sensor 20 can monitor how much indoor light the user is exposed to and how much outdoor light the user is exposed to for comparison. This type of information can indicate how severe the user's myopia progression may be, which in turn can be used to determine how much diffusion and / or peripheral defocus a particular user needs.

[0032] As Figure 2 shown, for example, the adjustable lens component 22 can have an effective area, such as effective area 48. Within the effective area 48, the adjustable lens component 22 can include one or more materials (e.g., liquid crystal materials) having an electrically adjustable refractive index. The control circuit 26 can dynamically adjust the phase distribution of the lens component 22. The effective area 48 can include a fixation area 46 and a peripheral area 50. The fixation area 46 corresponds to the portion of the lens component 22 within the user's fixation, while the peripheral area 50 corresponds to the portion of the lens component 22 outside the user's fixation (e.g., the portion of the lens component 22 in the user's peripheral vision). The fixation area 46 of the lens component 22 can be set with a different phase distribution than the peripheral area 50. For example, the fixation area 46 can be electrically modulated to produce a clear (undiffused) lens. The peripheral area 50 can be electrically modulated to produce an optical diffuser sheet that reduces the user's peripheral contrast (e.g., reduces the contrast of light passing through the peripheral area 50 relative to light passing through the fixation area 46), or can include a microlens array that introduces myopic defocus in the user's peripheral vision to help slow myopia progression. If desired, the diffusion distribution can decrease gradually from the peripheral area 50 to the fixation area 46 (e.g., the amount of diffusion can gradually decrease from the peripheral area 50 to the fixation area 46).

[0033] The control circuit 26 can dynamically adjust the position, size, resolution, or shape of the fixation area 46 and the peripheral area 50 during operation of the glasses 14. For example, the control circuit 26 can use the fixation tracking system 24 to track the user's fixation and can adjust the position of the fixation area 46 such that the fixation area remains aligned with the user's fixation. As Figure 2As shown, for example, the lens 22 can shift the position of the clear concave region from the fixation position 46 to the fixation position 46' to follow the user's gaze. If desired, the size of the fixation region 46 can be based on the size of the foveal region in the user's eye, the user's pupil diameter, and / or the desired phase distribution of the fixation region 46. The fixation region 46 can have, for example, a diameter D that is between 4 mm and 9 mm, between 7 mm and 9 mm, between 6 mm and 10 mm, between 4 mm and 8 mm, between 8 mm and 12 mm, greater than 10 mm, less than 10 mm, or any other suitable size. The size of the fixation region 46 can be based on the distance between the lens component 22 and the user's eye 16, can be based on the size of the user's pupil 52 (e.g., as measured by the sensor system 24 or as inferred based on an eye chart, ambient light level, or other data), and / or can be based on other information.

[0034] As used herein, a "concave" region can refer to any sized region of the lens 22 that is aligned with the user's gaze. If desired, the size of the region 46 need not match the size of the pupil. The size of the concave region 46 can be based, for example, on the accuracy of gaze prediction, current viewing conditions, the field of view angle perceived by the user, and / or other factors.

[0035] In the fixation region 46, the lens 22 can have a fixed refractive index to obtain a clear (undiffused) lens. In the peripheral region 50, the lens 22 can have a pseudo-random and variable refractive index to diffuse light in different directions and reduce the contrast in the user's peripheral vision. This can be achieved by applying an appropriate voltage distribution across an electrode array in the lens 22. For example, a fixed voltage can be applied across the electrodes passing through the fixation region 46, while a set of pseudo-randomly different voltages can be applied across the electrodes passing through the peripheral region 50. This creates a clear, undiffused lens in the fixation region 46 while reducing the contrast in the peripheral region 50. In a microlens array arrangement, the microlenses in the fixation region 46 can be controlled to allow light to pass through unchanged (e.g., without diffraction), while the microlenses in the peripheral region 50 can be used to refocus light in front of the retina (a mechanism sometimes referred to as myopic defocus). If desired, the lens 22 can be a bifocal or progressive lens that biases the power in the upper field of view relative to the lower field of view for distant and near viewing to reduce step changes and reduce power consumption.

[0036] Figure 3 A cross-sectional side view of an exemplary adjustable lens component is shown. As Figure 3As shown, component 22 may include liquid crystal cell 40. The liquid crystal cell 40 may have a voltage-modulated optical material layer, such as liquid crystal layer 34 (e.g., twisted nematic liquid crystal, electrically controlled birefringent nematic liquid crystal, polymer dispersed liquid crystal, or other suitable liquid crystal). The liquid crystal layer 34 may be interposed between transparent substrates such as upper substrate 32 and lower substrate 30. Substrates 32 and 30 may be formed of transparent glass, sapphire, or other transparent crystalline materials, cellulose triacetate, transparent plastics, or other transparent layers. Component 22 may have an electrode pattern, and the electrode pattern may be provided with signals from control circuit 26 to generate a desired voltage across component 22. In Figure 3 this example, these electrodes include elongated electrodes (e.g., bar electrodes), such as electrode 38 on substrate 30 extending along the X dimension; and a common electrode, such as common electrode 36 on substrate 32 (e.g., a covering layer of conductive material on substrate 32). Electrodes 36 and 38 may be formed of transparent conductive materials (such as indium tin oxide), conductive polymers (such as poly(3,4-ethylenedioxythiophene) polystyrenesulfonate (PEDOT:PSS)), or other transparent electrode structures, and may be located on the outer and / or inner surfaces of substrates 32 and 30.

[0037] At each position of electrode bar 38 in component 22, a desired voltage may be applied across liquid crystal layer 34 by applying a first voltage to electrode 38 and a second voltage (e.g., ground voltage) to common electrode 36. The liquid crystal between the two electrodes will receive the applied electric field, and the magnitude of this electric field is proportional to the difference between the first voltage and the second voltage on the electrodes. By controlling the voltages on electrode 38 and common electrode 36, the refractive index of liquid crystal layer 34 of component 22 can be dynamically adjusted to produce a customized lens.

[0038] In Figure 3 this example, bar electrode 38 (sometimes referred to as a finger electrode, patterned electrode, etc.) extends parallel to the X axis. This allows the refractive index distribution (sometimes referred to as the phase distribution) of liquid crystal cell 40 in the Y dimension to be modulated by applying a desired voltage to each finger electrode 38.

[0039] When an electric field is applied to the liquid crystal of layer 34, the liquid crystal changes orientation. The speed at which a given liquid crystal material can reorient is limited by factors such as the thickness of layer 34 (e.g., Figure 3 the thickness T1, sometimes referred to as the cell gap). To increase the tuning speed of liquid crystal layer 34 and still achieve a suitable tuning range, the adjustable lens component 22 may include two or more liquid crystal cells 40 stacked on top of each other. This type of arrangement is shown in Figure 4 .

[0040] As Figure 4As shown, the adjustable lens component 22 may include a liquid crystal module 44. The liquid crystal module 44 may include two or more liquid crystal cells 40. Each liquid crystal cell may include a liquid crystal layer 34 interposed between an upper substrate 32 and a lower substrate 30. Finger electrodes 38 may be formed on each lower substrate 30 and may extend parallel to the X-axis. A common electrode 36 may be formed on each upper substrate 32. If desired, the common voltage electrode 36 may be formed on the lower substrate 30, and the finger electrodes 38 may be formed on the upper substrate 32. Figure 3 and Figure 4 The examples of

[0041] The cell gap of each liquid crystal cell 40 in the module 44 may be less than Figure 3 the cell gap of the liquid crystal cell 40 of Figure 4 The liquid crystal layers 34 of the module 44 in Figure 3 may each have a thickness T2 that is less than the thickness T1 of the liquid crystal layer 34 in the cell 40 of

[0042] If desired, the liquid crystal alignment orientation (sometimes referred to as the rubbing direction) of the liquid crystal cells 40 in the module 44 may be anti-parallel. Specifically, the liquid crystal molecules 42A of the upper liquid crystal cell 40 may have a first liquid crystal orientation, and the liquid crystal molecules 42B of the lower liquid crystal cell 40 may have a second liquid crystal orientation that is anti-parallel to the first liquid crystal orientation. This type of arrangement may help reduce the angular dependence of the phase delay in the module 44.

[0043] At each position of the finger electrodes 38 in the component 22, a desired voltage may be applied across each liquid crystal layer 34 by applying a first voltage to the finger electrodes 38 and a second voltage (e.g., ground voltage) to the common electrode 36. The liquid crystal between the two electrodes will receive the applied electric field, and the magnitude of this electric field is proportional to the difference between the first voltage and the second voltage on the electrodes. By controlling the voltages on the electrodes 38 and the common electrode 36, the refractive index of each liquid crystal layer 34 of the component 22 can be dynamically adjusted to produce a customized lens. Since the finger electrodes 38 extend along the X dimension, the phase distribution of each liquid crystal cell 40 in the Y dimension can be modulated by applying a desired voltage to each finger electrode 38.

[0044] The overlapping portions of the two liquid crystal layers 34 in the module 44 can be controlled using the same or different voltages to achieve a desired refractive index at that portion of the module 44. For example, the finger electrodes 38A of the upper liquid crystal cell 40 in the module 44 can overlap with the finger electrodes 38B of the lower liquid crystal cell 40 in the module 44. A first voltage V1 can be applied across the portion of the upper liquid crystal layer 34 that overlaps with the finger electrode 38A, and a second voltage V2 can be applied across the portion of the lower liquid crystal layer 34 that overlaps with the finger electrode 38B. The voltages V1 and V2 can be different or can be the same. The control circuit 26 can determine the ratio of V1 to V2 based on the desired refractive index at that portion of the liquid crystal module 44 and based on the settings of the user's eye 16.

[0045] In Figure 3 and Figure 4 example, the adjustable lens component 22 includes electrodes extending in one direction (e.g., Figure 3 and Figure 4 the X dimension), thereby allowing the adjustable lens component 22 to modulate the phase distribution of the component 22 in one direction (e.g., Figure 3 and Figure 4 the Y dimension). If desired, the adjustable lens component 22 can include electrodes extending in multiple directions, thereby allowing the adjustable lens component 22 to modulate the phase distribution of the component 22 in multiple directions.

[0046] Figure 5 is a perspective view of an exemplary adjustable lens component 22 having a first liquid crystal cell 40 and a second liquid crystal cell 40, the first liquid crystal cell having first finger electrodes 38-1 oriented in a first direction, the second liquid crystal cell having second finger electrodes 38-2 oriented in a second direction different from the first direction. The first finger electrodes 38-1 can be oriented at a 90-degree angle relative to the second finger electrodes 38-2, for example, or other suitable orientations can be used. Each set of electrodes can modulate the phase distribution of the liquid crystal layer along the associated dimension. Thus, an adjustable lens component 22 of the type shown in Figure 5 can be used to create a phase distribution that varies along two dimensions.

[0047] Some types of liquid crystals only modulate light of one polarization, such that light of other polarizations (e.g., the polarization direction orthogonal to the rubbing direction in the electro-optic birefringence cell) is largely unmodulated. If desired, additional layers having different rubbing directions (e.g., having rubbing directions that are ninety degrees apart from each other) can be employed such that both polarizations can be modulated by the adjustable lens component 22. Alternatively, a polarization filter that removes the unmodulated polarization of the light can be added to the module.

[0048] Figure 6 is a diagram showing across Figure 5Graph of an exemplary voltage distribution applied to electrodes 38-1 and 38-2. As Figure 6 shown, a pseudo-random array of voltages can be applied to electrodes P0 to P1, and to electrodes P2 to P3. Electrodes P0 to P1 and electrodes P2 to P3 can be located in the peripheral region 50 of the lens 22. Thus, these electrodes can be used to reduce the contrast in the user's peripheral vision by diffusing light through the liquid crystal cells 40 in those regions. A fixed voltage can be applied to electrodes P1 to P2, or if desired, the voltages applied to electrodes P1 and P2 can vary only slightly such that the resulting electric fields in the liquid crystal are all sub-threshold and do not cause a significant phase effect. Electrodes P1 to P2 can be located in the fixation region 46 of the lens 22. Thus, these electrodes can be used to provide a clear, non-diffused region through which the user can view external objects, such as object 18( Figure 1 ).

[0049] The control circuit 26 can monitor the gaze tracking sensor 24 for changes in the user's gaze position. As the user's gaze moves around, the control circuit 26 can adjust the positions of the concave clear region 46 and the diffused peripheral region 50 on the lens 22. The control circuit 26 can adjust the position of the clear region 46 by adjusting which electrodes 38 receive a fixed voltage and which electrodes receive a portion of the pseudo-random array of voltages. The control circuit 26 can also monitor additional sensor data from sensors such as sensor 20. If sensor 20 indicates that the glasses 14 are being used outdoors, the glasses 14 are being used while the user is talking to someone, or the glasses 14 are being used to view a distant object, the control circuit 26 can apply a fixed voltage across the entire array of electrodes 38 to obtain a completely clear lens 22 through which the user can view external objects.

[0050] If desired, the lens component 22 can include more than two liquid crystal cells 40 and more than two electrode orientations. For example, the lens component 22 can include three liquid crystal cells 40 having three different electrode orientations, four liquid crystal cells 40 having four different electrode orientations, five liquid crystal cells 40 having five different electrode orientations, and so on.

[0051] If desired, the liquid crystal material 34 can have a high dispersibility and can be configured to diffuse or refract blue light more than red light in the user's peripheral vision (e.g., in region 50). If desired, an arrangement can also be used in which the liquid crystal material 34 preferentially diffuses or refracts light in a given direction (e.g., a radial direction or a tangential direction) to help focus the light in front of the retina.

[0052] In Figure 5In an arrangement of the type shown, each liquid crystal cell 40 includes finger electrodes 38 (e.g., patterned strip finger electrodes) and a blanket common electrode 36. With this type of arrangement, the control circuit 26 can be configured to apply a one-dimensional voltage distribution across each liquid crystal layer 34. For example, the strip electrode 38-1 (sometimes referred to as a finger electrode, patterned electrode, etc.) extends parallel to the X-axis, allowing the refractive index distribution (sometimes referred to as the phase distribution) of the liquid crystal cell 40 to be modulated in the Y dimension. The electrode 38-2 extends parallel to the Y-axis, allowing the refractive index distribution of the liquid crystal cell 40 to be modulated in the X dimension.

[0053] In other arrangements, both the upper electrode array and the lower electrode array in the cell 40 can include strip finger electrodes, forming a grid of orthogonal (or otherwise non-parallel) conductive lines that can be driven at different voltages using a passive matrix addressing scheme. Figure 7 An arrangement of this type is illustrated in

[0054] As Figure 7 shown in the example of , the finger electrodes 38 can extend along the X dimension on the substrate 30, and the finger electrodes 36 can extend along the Y dimension on the substrate 32. If desired, the finger electrodes 38 can extend along the Y dimension on the substrate 30, and the finger electrodes 36 can extend along the X dimension on the substrate 32. Figure 7 The examples of are merely illustrative. The electrodes 36 and 38 can be formed of a transparent conductive material (such as indium tin oxide), a conductive polymer (such as poly(3,4-ethylenedioxythiophene) polystyrenesulfonate (PEDOT:PSS)), silver nanowires, or other transparent electrode structures, and can be located on the outer and / or inner surfaces of the substrates 32 and 30.

[0055] In Figure 7 the example of , the electrodes 38 and 36 are oriented at 90 degrees relative to each other. This is merely illustrative. Generally, the electrodes 38 and 36 can be separated by 60 degrees, 80 degrees, 110 degrees, 130 degrees, 160 degrees, and / or any other suitable angle between 0 degrees and 180 degrees. An arrangement in which the electrodes 38 and 36 are orthogonal to each other is sometimes described herein as an illustrative example.

[0056] In a passive matrix drive scheme in which the electrodes 38 and the electrode 36 are patterned finger electrodes extending in two orthogonal (or otherwise non-parallel) directions, the control circuit 26 can be configured to control the phase distribution of the liquid crystal layer 34 in two dimensions. The voltage at each liquid crystal "pixel" where a given upper electrode 36 overlaps a given lower electrode 38 can be equal to the difference between the voltage applied to the upper electrode 36 and the voltage applied to the lower electrode 38. By controlling the voltages on the electrodes 36 and the electrode 38, the refractive index of the liquid crystal layer 34 of the component 22 can be across two different directions (e.g.,Figure 7 dynamically adjusted in the X and Y dimensions) to produce a clear lens in the concave region 46 and a diffused lens in the peripheral region 50 ( Figure 2 ).

[0057] Figure 8 is a graph showing an exemplary voltage distribution that can be applied across Figure 7 electrodes 36 and 38. Voltage distribution 58 can be applied to electrode 36. Voltage distribution 60 can be applied to electrode 38. As Figure 8 shown, a pseudo-random array of voltages can be applied to peripheral electrodes P0 to P1 and to peripheral electrodes P2 to P3. Electrodes P0 to P1 and electrodes P2 to P3 can be located in the peripheral region 50 of lens 22. Thus, these electrodes can be used to reduce the contrast in the user's peripheral vision by diffusing the light passing through the liquid crystal cells 40 in those regions. Electrodes P1 to P2 can be located in the fixation region 46 of lens 22. Thus, these electrodes can be used to provide a clear, non-diffused region through which the user can view external objects, such as object 18 ( Figure 1 ). A fixed voltage can be applied to electrodes P1 to P2, or if desired, the voltages applied to electrodes P1 and P2 can vary only slightly such that the resulting electric fields in the liquid crystal are all sub-threshold and do not cause significant phase effects. The presence of some sub-threshold variations in the concave region 46 can help avoid the appearance of significant vertical and horizontal stripes in the concave region 46 while still maintaining a clear region in lens 22. As Figure 8 shown, voltage distribution 58 can be the inverse of voltage distribution 60 (e.g., the electrodes 36 in positions P1 to P2 can receive a positive voltage +V, while the electrodes 38 in positions P1 to P2 can receive a negative voltage -V). Figure 8 The voltages +V and -V in

[0058] are merely exemplary. If desired, voltage distribution 58 can not be the inverse of voltage distribution 60 (e.g., the electrodes 36 in positions P1 to P2 can receive a positive voltage +V_1, while the electrodes 38 in positions P1 to P2 can receive a negative voltage -V_2).

[0058] In the Figure 9 example, liquid crystal layer 34 is formed of a polymer dispersed liquid crystal material. As Figure 9As shown, the liquid crystal layer 34 may include liquid crystal droplets 54 dispersed in a host layer (such as host layer 56) (e.g., a polymer matrix) between the transparent substrates 32 and 30. Transparent conductive materials such as electrodes 36 and 38 (e.g., indium tin oxide or other transparent conductive materials) may be formed on substrates 32 and 30, respectively, to control the behavior of the liquid crystal droplets 54. The control circuit 26 may apply a voltage distribution across electrode 38 to control the orientation of the liquid crystal material in the droplets 54. For example, when no voltage is applied across electrode 38 in the peripheral region 50, the liquid crystal droplets 54 may have a random orientation and may thus be diffused (e.g., blurry). In the fixation region 46, a voltage is applied across electrode 38 to align the liquid crystal droplets 54 and create a clear concave region with little to no haze. As the user's fixation moves around, the control circuit 26 may adjust which pixels (e.g., electrodes) are turned off (and thus are diffused) and which electrodes are turned on (and thus are clear).

[0059] Electrode 36 may be a blanket common electrode, and electrode 38 may be an array of finger electrodes (e.g., similar to the electrode arrangement of Figure 5 ), or electrode 36 and electrode 38 may be a first set of orthogonal electrode arrays and a second set of orthogonal electrode arrays in a passive matrix addressing scheme (e.g., similar to the arrangement of Figure 7 ). An arrangement may also be used in which electrode 36 is a blanket common electrode and electrode 38 is an array of pixelated electrodes (e.g., rectangular electrodes, hexagonal electrodes, disc-shaped electrodes, and / or other pixelated electrodes). If pixelated electrodes are not desired, an alternative drive scheme for the polymer dispersed liquid crystal cell is to have a linear arrangement of the transparent electrode 38 as illustrated in Figure 5 and Figure 7 in combination with a drive scheme in which the voltage in the fixation region 46 is greater in magnitude than the voltage in the peripheral region 50.

[0060] When using a polymer dispersed liquid crystal material, if desired, electrode 38 may be arranged in a two-dimensional pixelated configuration. The pitch between pixels may be between 1.5 mm and 2.5 mm, between 2 mm and 3 mm, between 1 mm and 2 mm, less than 1 mm, more than 3 mm, or any other desired pitch. The arrangement of these pixelated electrodes may be a square or rectangular regular array, a regular hexagonal array, a deformed hexagonal or rectangular array, an irregular checkerboard arrangement, or any other desired configuration.

[0061] If desired, the liquid crystal material 34 may have high dispersibility and may be configured to diffract or refract blue light more than red light in the user's peripheral vision (e.g., in region 50). If desired, an arrangement may also be used in which the liquid crystal material 34 preferentially diffracts or refracts light in a given direction (e.g., a radial or tangential direction) to help focus the light in front of the retina.

[0062] Figure 10 and Figure 11 An exemplary arrangement is shown in which the lens component 22 includes an adjustable microlens array. As Figure 10 shown, the lens 22 may include a two-dimensional array of adjustable microlenses, such as microlenses 60 on a substrate 62. The substrate 62 may be a layer of transparent glass, plastic, ceramic, or other suitable material. The microlenses 60 may include liquid crystal microlenses or other tunable microlenses. In the peripheral region 50, the microlenses 60 may have a pseudo-random array of different lens powers to help create defocus in the user's peripheral vision. In the fixation region 46, the microlenses 60F may have a fixed lens power (e.g., zero lens power) to provide a clear area through which the user can view external objects. As Figure 11 shown, the control circuit 26 may actively switch which microlenses 60F are optically flat (e.g., have zero optical power), and which microlenses 60 are provided with an array of different microlens powers to defocus the light in region 50.

[0063] The microlenses 60 may be electrowetting tunable lenses (sometimes referred to as microdroplet lenses), or the microlenses 60 may be tunable liquid crystal lenses or adjustable microlenses based on other voltage-tunable optical materials. In a liquid crystal microlens, the liquid crystal material is contained within a cladding, and electrodes are used to apply an electric field to the liquid crystal material. When no voltage is applied (e.g., to the microlenses 60F in the concave region 46), the refractive index of the liquid crystal material matches the refractive index of the cladding such that light passes through the microlenses 60F without being refracted. When a voltage is applied (e.g., to the microlenses 60 in the peripheral region 50), the difference in refractive index between the liquid crystal material and the cladding adds optical power to the microlenses 60 (e.g., light is refracted as it passes through the microlenses 60).

[0064] Some of the figures include cross-sectional views and may or may not include hatching for inclined sections. In some cases, the hatching for inclined sections in the cross-sectional views may be omitted to avoid obscuring the clear reading of reference numerals and front leads.

[0065] According to an embodiment, there is provided a pair of glasses, the pair of glasses comprising: a support frame; a gaze tracking sensor coupled to the support frame and configured to track a gaze position; and a first lens and a second lens coupled to the support frame, wherein each of the first lens and the second lens includes a clear concave region and a peripheral region, the clear concave region being aligned with and moving with the gaze position, the peripheral region surrounding the clear concave region, wherein light passing through the peripheral region is selected from the group consisting of: refocused light and diffused light.

[0066] According to another embodiment, each of the first lens and the second lens optionally includes a liquid crystal material.

[0067] According to another embodiment, the liquid crystal material is optionally selected from the group consisting of: twisted nematic liquid crystal materials, polymer dispersed liquid crystal materials, and electrically controlled birefringent nematics.

[0068] According to another embodiment, the liquid crystal material is optionally configured to preferentially diffuse light in a direction selected from the group consisting of: a tangential direction and a radial direction.

[0069] According to another embodiment, the liquid crystal material is optionally configured to diffuse blue light more than red light in the peripheral region.

[0070] According to another embodiment, the liquid crystal material is optionally sandwiched between a blanket common electrode and a finger electrode array.

[0071] According to another embodiment, the liquid crystal material is optionally sandwiched between a first array of electrodes and a second array of electrodes, the first array of electrodes extending in a first direction and the second array of electrodes extending in a second direction orthogonal to the first direction.

[0072] According to another embodiment, the liquid crystal material is optionally sandwiched between a blanket common electrode and a pixelated electrode array.

[0073] According to another embodiment, each of the first lens and the second lens optionally includes an adjustable microlens array, and wherein the adjustable microlens array is optionally adjusted based on the gaze position.

[0074] According to another embodiment, each of the first lens and the second lens optionally includes a liquid crystal material controlled by an electrode array, the pair of glasses optionally includes a control circuit configured to apply a voltage distribution across the electrode array, and wherein the voltage distribution optionally includes a pseudo-random array of different voltages in the peripheral region and a fixed voltage in the clear concave region.

[0075] According to an embodiment, a lens is provided, the lens comprising: a first transparent substrate and a second transparent substrate; a liquid crystal material interposed between the first transparent substrate and the second transparent substrate; and an array of a first electrode and a second electrode, the first electrode being located on the first transparent substrate and the array of the second electrode being located on the second transparent substrate, wherein the first electrode and the array of the second electrode are configured to apply an electric field to the liquid crystal material to create a clear concave region and a diffusive peripheral region surrounding the clear concave region.

[0076] According to another embodiment, the first electrode is optionally a blanket common electrode.

[0077] According to another embodiment, the first electrode is optionally part of an array of first electrodes located on the first transparent substrate, and wherein the first electrode is optionally orthogonal to the second electrode.

[0078] According to another embodiment, the liquid crystal material is optionally selected from the group consisting of: twisted nematic liquid crystal materials, polymer dispersed liquid crystal materials, and electrically controlled birefringent nematics.

[0079] According to another embodiment, the liquid crystal material is optionally configured to preferentially diffuse light in directions selected from the group consisting of: a tangential direction and a radial direction.

[0080] According to another embodiment, the liquid crystal material is optionally configured to diffuse blue light more than red light in the diffusive peripheral region.

[0081] According to an embodiment, a pair of glasses is provided, the pair of glasses comprising a left adjustable lens and a right adjustable lens, wherein the first adjustable lens and the second adjustable lens each have a clear concave region surrounded by a peripheral region, and wherein light passes through the clear concave region without being changed and is changed as it passes through the peripheral region. <T

[0082] According to another embodiment, the pair of glasses optionally includes a gaze tracking sensor configured to track a gaze position, wherein the clear concave region optionally follows the gaze position.

[0083] According to another embodiment, the first adjustable lens and the second adjustable lens each optionally include a switchable liquid crystal diffuser that diffuses the light passing through the peripheral region.

[0084] According to another embodiment, the first adjustable lens and the second adjustable lens each optionally include an adjustable microlens array that refocuses the light passing through the peripheral region.

[0085] The foregoing is merely illustrative and various modifications may be made to the embodiments. The foregoing embodiments may be implemented individually or in any combination.

Claims

1. A pair of glasses, the pair of glasses comprising: A support frame; A gaze tracking sensor coupled to the support frame and configured to track a gaze position; And A first lens and a second lens, the first lens and the second lens being coupled to the support frame, wherein each of the first lens and the second lens comprises: A clear concave region that is aligned with and moves with the gaze position, and A peripheral region that surrounds the clear concave region, wherein light passing through the peripheral region is selected from the group consisting of: refocused light and diffused light.

2. The pair of glasses according to claim 1, wherein each of the first lens and the second lens comprises a liquid crystal material.

3. The pair of glasses according to claim 2, wherein the liquid crystal material is selected from the group consisting of: twisted nematic liquid crystal material, polymer dispersed liquid crystal material, and electrically controlled birefringent nematic liquid crystal.

4. The pair of glasses according to claim 2, wherein the liquid crystal material is configured to preferentially diffuse light in a direction selected from the group consisting of: a tangential direction and a radial direction.

5. The pair of glasses according to claim 2, wherein the liquid crystal material is configured to diffuse blue light more than red light in the peripheral region.

6. The pair of glasses according to claim 2, wherein the liquid crystal material is sandwiched between a carpet-like common electrode and a finger-like electrode array.

7. The pair of glasses according to claim 2, wherein the liquid crystal material is sandwiched between a first array of electrodes and a second array of electrodes, the first array of electrodes extending in a first direction and the second array of electrodes extending in a second direction orthogonal to the first direction.

8. The pair of glasses according to claim 2, wherein the liquid crystal material is sandwiched between a carpet-like common electrode and a pixelated electrode array.

9. The pair of glasses according to claim 1, wherein each of the first lens and the second lens comprises an adjustable microlens array, and wherein the adjustable microlens array is adjusted based on the gaze position.

10. The pair of glasses according to claim 1, wherein each of the first lens and the second lens comprises a liquid crystal material controlled by an electrode array, the pair of glasses further comprising a control circuit configured to apply a voltage distribution across the electrode array, and wherein the voltage distribution comprises a pseudo-random array of different voltages located in the peripheral region and a fixed voltage located in the clear concave region.

11. A lens, the lens comprising: A first transparent substrate and a second transparent substrate; A liquid crystal material interposed between the first transparent substrate and the second transparent substrate; And An array of a first electrode and a second electrode, the first electrode being located on the first transparent substrate and the array of the second electrode being located on the second transparent substrate, wherein the array of the first electrode and the second electrode is configured to apply an electric field to the liquid crystal material to create a clear concave region and a diffused peripheral region surrounding the clear concave region.

12. The lens according to claim 11, wherein the first electrode is a blanket common electrode.

13. The lens according to claim 11, wherein the first electrode is part of an array of first electrodes on the first transparent substrate, and wherein the first electrode is orthogonal to the second electrode.

14. The lens according to claim 11, wherein the liquid crystal material is selected from the group consisting of: twisted nematic liquid crystal materials, polymer dispersed liquid crystal materials, and electrically controlled birefringent nematics.

15. The lens according to claim 11, wherein the liquid crystal material is configured to preferentially diffuse light in directions selected from the group consisting of: the tangential direction and the radial direction.

16. The lens according to claim 11, wherein the liquid crystal material is configured to diffuse blue light more than red light in the diffusion peripheral region.

17. A pair of glasses, the pair of glasses comprising: a left adjustable lens; and a right adjustable lens, wherein the first adjustable lens and the second adjustable lens each have a clear concave region surrounded by a peripheral region, and wherein light passes through the clear concave region unchanged and is altered as it passes through the peripheral region.

18. The pair of glasses according to claim 17, the pair of glasses further comprising a gaze tracking sensor configured to track a gaze position, wherein the clear concave region follows the gaze position.

19. The pair of glasses according to claim 17, wherein the first adjustable lens and the second adjustable lens each comprise a switchable liquid crystal diffuser that diffuses the light passing through the peripheral region.

20. The pair of glasses according to claim 17, wherein the first adjustable lens and the second adjustable lens each comprise an adjustable microlens array that refocuses the light passing through the peripheral region.

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