Superlens assembly and electronic device comprising the same

Abstract

A superlens assembly includes: a first superlens; a second superlens disposed on the image side of the first superlens; and a third superlens disposed on the image side of the second superlens, wherein the first superlens, the second superlens, and the third superlens are arranged from the object side of the superlens assembly to the image side of the superlens assembly facing an image sensor.

Description

[0001] Cross-references to related applications

[0002] This application is based on and claims priority to U.S. Provisional Application No. 63 / 077,151, filed September 11, 2020, with the U.S. Patent and Trademark Office, and Korean Patent Application No. 10-2021-0053757, filed April 26, 2021, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This disclosure relates to lens assemblies including meta lenses and electronic devices including such lens assemblies. Background Technology

[0004] Digital cameras or video cameras, including image sensors such as CCD image sensors and complementary metal-oxide-semiconductor (CMOS) image sensors, are already used as optical devices for capturing images or videos. To obtain high-quality images and / or video, lens assemblies comprising a combination of multiple lenses can be used in optical devices. Lens assemblies can be mounted on augmented reality (AR) or virtual reality (VR) devices, as well as small electronic devices such as portable wireless terminals.

[0005] VR devices display virtual images to users, while AR devices display AR images overlaid on real-world images. For users, the image display of either AR or VR devices requires small size and high performance. Mobile ultra-miniature image sensors, typically about 1 inch or less, usually require at least three aspherical refractive lenses to image short-wavelength light in the near-infrared band. Refractive lenses are space-constrained within the assembly due to the cumulative lens thickness resulting from the minimum thickness of the lens edges used for processing. Summary of the Invention

[0006] A microlens assembly using a superlens is provided.

[0007] Wide-angle super lens assembly is provided.

[0008] Electronic devices including wide-angle superlens assemblies are provided.

[0009] Additional aspects will be set forth in part in the description which follows, and will also be apparent in part from the description, or may be learned by practice of embodiments of the present disclosure.

[0010] According to one aspect of this disclosure, a superlens assembly includes: a first superlens; a second superlens disposed on the image side of the first superlens; and a third superlens disposed on the image side of the second superlens, wherein the first, second, and third superlenses are arranged from the object side of the superlens assembly toward the image side of the superlens assembly facing an image sensor, and wherein the spacing between the first and second superlenses is less than or equal to about 1 / 5 of the spacing between the second and third superlenses.

[0011] The phase distribution of the second superlens can have an inflection point, where the phase distribution changes from concave to convex.

[0012] The inflection point of the second superlens can be between the midpoint of the radius of the second superlens and the edge of the second superlens.

[0013] The phase distribution of the third superlens can have an inflection point, where the phase distribution changes from convex to concave.

[0014] The inflection point of the third superlens can be between the midpoint of the radius of the third superlens and the edge of the third superlens.

[0015] The superlens assembly may further include: an aperture in the edge portion of the first superlens, wherein the aperture includes a material that absorbs or reflects light, and wherein the aperture defines an area through which light passes through the first superlens.

[0016] The first superlens can have a first positive refractive power, the second superlens can have a negative refractive power, and the third superlens can have a second positive refractive power.

[0017] The first diameter of the first superlens can be smaller than the third diameter of the third superlens, and the second diameter of the second superlens can be smaller than the third diameter of the third superlens.

[0018] The spacing between the first and second superlenses can be in the range of approximately 10µm to approximately 100µm.

[0019] The distance from the first superlens to the image sensor can be less than or equal to about 1.7 mm.

[0020] The superlens assembly may also include a cover glass on the object side of the first superlens.

[0021] The superlens assembly can have a field of view of approximately 40 degrees to approximately 80 degrees.

[0022] The superlens assembly may also include a cover glass between the third superlens and the image sensor.

[0023] Each of the first, second, and third superlenses may include multiple nanostructures.

[0024] The superlens assembly may further include a first transparent substrate between the first superlens and the second superlens, and a second transparent substrate between the second superlens and the third superlens.

[0025] The second superlens may include a first region comprising a first nanostructure and a second region comprising a second nanostructure, wherein the first nanostructure in the first region is arranged to gradually increase in size along the radial direction of the second superlens, and wherein the second nanostructure in the second region is arranged to gradually decrease in size along the radial direction of the second superlens.

[0026] The third superlens may include a third region comprising a third nanostructure and a fourth region comprising a fourth nanostructure, wherein the third nanostructure in the third region is arranged to gradually decrease in size along the radial direction of the third superlens, and wherein the fourth nanostructure in the fourth region is arranged to gradually increase in size along the radial direction of the third superlens.

[0027] According to one aspect of this disclosure, an electronic device includes: a superlens assembly in which a plurality of superlenses are arranged from the object side of the superlens assembly to the image side of the superlens assembly; an image sensor for detecting an image of an object based on incident light sequentially passing through the plurality of superlenses; and an image signal processor for storing or outputting the image, wherein the superlens assembly includes: a first superlens; a second superlens arranged on the image side of the first superlens; and a third superlens arranged on the image side of the second superlens, wherein the first, second, and third superlenses are arranged facing the image sensor from the object side of the superlens assembly to the image side of the superlens assembly, and wherein the spacing between the first and second superlenses is less than or equal to about 1 / 5 of the spacing between the second and third superlenses.

[0028] The phase distribution of the second superlens can have an inflection point, where the phase distribution changes from concave to convex.

[0029] The inflection point of the second superlens can be between the midpoint of the radius of the second superlens and the edge of the second superlens.

[0030] The phase distribution of the third superlens can have an inflection point, where the phase distribution changes from convex to concave.

[0031] The inflection point of the third superlens can be between the midpoint of the radius of the third superlens and the edge of the third superlens.

[0032] The electronic device may further include: an aperture in the edge portion of the first superlens, wherein the aperture includes a material that absorbs or reflects light, and wherein the aperture defines an area through which light passes through the first superlens.

[0033] The first superlens can have a first positive refractive power, the second superlens can have a negative refractive power, and the third superlens can have a second positive refractive power.

[0034] According to one aspect of this disclosure, a camera includes: at least one superlens; and an image sensor, wherein the distance from the incident surface of the camera to the image sensor is less than or equal to about 1.7 mm, and wherein the viewing angle of the camera is between about 40 degrees and about 80 degrees.

[0035] At least one superlens can have a diameter smaller than the diagonal length of the image sensor.

[0036] At least one superlens may include a first superlens, a second superlens, and a third superlens.

[0037] The distance between the incident surface of the first superlens and the incident surface of the second superlens can be in the range of about 10µm to about 100µm.

[0038] The distance between the incident surface of the second superlens and the incident surface of the third superlens can be in the range of about 100µm to about 600µm. Attached Figure Description

[0039] The above and other aspects, features, and advantages of some embodiments of this disclosure will become clearer from the following description taken in conjunction with the accompanying drawings, in which:

[0040] Figure 1 A superlens assembly according to an embodiment is schematically shown;

[0041] Figure 2 The phase distribution relative to the radius of the superlens assembly according to an embodiment is shown;

[0042] Figures 3 to 6 The arrangement of the nanostructure of the superlens according to an embodiment is shown;

[0043] Figures 7 to 10 A superlens assembly according to an embodiment is shown;

[0044] Figure 11A This is a cross-sectional view of the superlens assembly according to an embodiment;

[0045] Figure 11B An example of a nanostructure included in a superlens assembly according to an embodiment is shown;

[0046] Figures 12A to 12H Various examples of nanostructures included in the superlens of the superlens assembly according to embodiments are shown;

[0047] Figure 13 This is a cross-sectional view of the superlens assembly according to an embodiment;

[0048] Figure 14A It shows Figure 13 The cross-section of the nanostructure;

[0049] Figure 14B and Figure 14C yes Figure 14A Cross-sectional views of the first and second phase-shifting layers of the nanostructure;

[0050] Figure 14D It also includes a cross-sectional view of the nanostructure, which contains spacer layers;

[0051] Figure 15 This is a block diagram of an electronic device in a network environment according to an embodiment;

[0052] Figure 16 It is shown in detail Figure 15 A block diagram of the camera module; and

[0053] Figures 17 to 23 An example of an electronic device that applies a superlens assembly according to an embodiment is shown. Detailed Implementation

[0054] Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein similar elements are indicated by similar reference numerals throughout the drawings. In this respect, embodiments may take different forms and should not be construed as limited to the description set forth herein. Therefore, embodiments are described below only with reference to the accompanying drawings to explain various aspects. The term “and / or” as used herein includes any one and all combinations of one or more of the relevant listed items. Expressions such as “at least one of…” modify the entire list of elements when following a list of elements, rather than modifying individual elements in the list.

[0055] In the following description, various embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the embodiments and the terminology used therein are not intended to limit the present disclosure to the specific embodiments, but should be construed as including various modifications, equivalents, and / or substitutions according to the embodiments of the present disclosure. Throughout the specification and drawings, the same or similar reference numerals may be used to refer to the same or similar parts. It will be understood that the singular form includes plural references unless the context clearly indicates otherwise. In embodiments of the present disclosure, expressions such as “A or B” or “A and / or B” may include all possible combinations of items listed together. Expressions such as “first,” “second,” “primary,” or “minor” used herein may denote various elements without regard to order and / or importance, and do not limit the corresponding elements. When a (first) component is described as being “operably or communicatively coupled to” or “connected” to another (second) component, the component may be directly connected to the other component or may be connected to the other component through yet another (third) component.

[0056] In embodiments of this disclosure, the expression "configured as (or set)" may be replaced, for example, with "suitable for," "capable of," "suitable for," "made for," "capable of," or "designed for." Alternatively, in some cases, the expression "the device is configured as" may mean that the device "can" operate with another device or component. For example, the phrase "processor configured (or set) to perform A, B, and C" may be a dedicated processor (e.g., an embedded processor, etc.) for performing the corresponding operations or a general-purpose processor (e.g., a central processing unit (CPU) or AP) that can perform the corresponding operations by executing at least one software program stored in a storage device. The term "configured as (or set)" does not always mean "specifically designed for" only by hardware.

[0057] Unless otherwise specified, the radius of curvature, thickness, total length (TTL), focal length, etc., of a lens may be expressed in millimeters (mm). The thickness of a lens, the spacing between lenses, and the TTL of a lens may be distances measured relative to the optical axis of the lens. Furthermore, in the description of the shape of a lens, a convex surface may indicate that the surface of the optical axis portion is convex, while a concave surface may indicate that the surface of the optical axis portion is concave. Therefore, even when the surface of a lens (its optical axis portion) is described as convex, the edge of the lens (the portion at a specific distance from the surface of the optical axis portion) may be concave. Similarly, even when the surface of a lens (its optical axis portion) is described as concave, the edge of the lens (the portion at a specific distance from the surface of the optical axis portion) may be convex. Moreover, when the surface pointing towards the image side is convex, it may indicate that the surface has a shape that bulges (protrudes) towards the image side; when the surface pointing towards the object side is convex, it may indicate that the surface has a shape that bulges (protrudes) towards the object side.

[0058] Examples of electronic devices according to embodiments of this disclosure may include at least one of the following: smartphones, tablet PCs, mobile phones, video phones, e-book readers, desktop PCs, laptop computers, notebook computers, workstations, servers, personal digital assistants (PDAs), portable multimedia players (PMPs), MP3 players, medical devices, cameras, or wearable devices. Wearable devices may include: jewelry devices (e.g., watches, rings, bracelets, anklets, necklaces, glasses, contact lenses, or head-mounted devices (HMDs), etc.), clothing or garment-integrated devices (e.g., electronic clothing), body-attached devices (e.g., skin patches, tattoos, etc.), or implanted devices. In some embodiments of this disclosure, electronic devices may include: for example, televisions (TVs), digital video disc (DVD) players, audio equipment, refrigerators, air conditioners, vacuum cleaners, ovens, microwave ovens, washing machines, air purifiers, set-top boxes, home automation control panels, security control panels, media boxes (e.g., Samsung HomeSync). TM Apple TV TM or Google TV TM ), game consoles (e.g., Xbox) TM PlayStation TM (etc.), electronic dictionary, electronic key, camera or electronic photo frame.

[0059] Electronic devices can include various medical equipment (e.g., various portable medical measurement devices (blood glucose meters, heart rate meters, blood pressure meters, body temperature meters, etc.), magnetic resonance angiography (MRA), magnetic resonance imaging (MRI), computed tomography (CT), imaging equipment, or ultrasound equipment), navigation systems, global positioning systems (global navigation satellite systems (GNSS)), event data loggers (EDR), flight data loggers (FDR), in-vehicle entertainment systems, marine electronic equipment (e.g., marine navigation systems and gyrocompasses), aviation equipment, security equipment, vehicle head units, industrial or household robots, drones, automated teller machines (ATMs), point of sale (POS), and the Internet of Things (IoT) (e.g., light bulbs, various sensors, electricity or gas meters, sprinkler systems, fire alarm systems, thermostats, streetlights, toasters, fitness equipment, kettles, heaters, boilers, etc.). Electronic devices can also include parts of furniture, buildings / structures or vehicles, electronic boards, electronic signature receiving devices, projectors, and / or various measuring instruments (e.g., water meters, electricity meters, gas meters, radio wave measuring devices, etc.). Electronic devices can be flexible, or can be a combination of two or more of the various devices described above. The term "user" can refer to a person using an electronic device or a device using an electronic device (e.g., an artificial intelligence electronic device). Representative examples of electronic devices can include optical devices (cameras, etc.), and the following description will be based on embodiments of this disclosure in which a lens assembly is mounted on an optical device.

[0060] When describing embodiments of this disclosure, some values ​​may be provided, but these values ​​do not limit the scope of this disclosure unless described in the claims.

[0061] Figure 1 A superlens assembly according to an embodiment of the present disclosure is shown.

[0062] refer to Figure 1 The lens assembly 100 may include a first superlens 110, a second superlens 120, and a third superlens 130 arranged from the object side O of the lens assembly 100 to the image side I of the lens assembly 100. The first superlens 110, second superlens 120, and third superlens 130 may include nanostructures to be described later. The first superlens 110 may include an incident surface 110a for light incidence and an exit surface 110b for light emission; the second superlens 120 may include an incident surface 120a and an exit surface 120b; and the third superlens 130 may include an incident surface 130a and an exit surface 130b. Nanostructures may be included on the incident surface and / or exit surface of each superlens.

[0063] Lens assembly 100 may have an optical axis OI from the object (or external object) side O to the image side I. When describing the configuration of each lens, the object side O may represent the direction in which the object is placed, while the image side I may represent the direction in which the imaging plane forming the image is placed. The lens surface pointing towards the object side O is the surface on the side where the object is placed relative to the optical axis OI, which may represent the surface on which light is incident in the figures, while the surface pointing towards the image side I is the surface on the side where the imaging plane is placed relative to the optical axis OI, which may represent the surface on which light is emitted. The imaging plane may be part of an imaging device or an image sensor 150 that forms an image.

[0064] Image sensor 150 is a sensor mounted on a circuit board and arranged aligned with the optical axis OI of the superlens assembly 100, capable of responding to light. For example, image sensor 150 can be a sensor such as a complementary metal-oxide-semiconductor (CMOS) image sensor or an electrical-coupled device (CCD) image sensor, and can convert an object image into an electrical image signal. Image sensor 150 can detect contrast information, grayscale information, color information, etc., about an object from light passing through the first superlens 110, the second superlens 120, and the third superlens 130, and obtain an object image.

[0065] To describe a superlens, the portion of each superlens near the optical axis OI can be referred to as the principal portion, while the portion away from the optical axis OI (or the edge of the lens) can be referred to as the edge portion. The principal portion can be the portion of each of the first superlens 110, the second superlens 120, and the third superlens 130 that intersects the optical axis OI, while the edge portion can include the portion of each of the first superlens 110, the second superlens 120, and the third superlens 130 that is at a specific distance from the optical axis OI (e.g., the end of each of the first superlens 110, the second superlens 120, and the third superlens 130 that is farthest from the optical axis OI).

[0066] The first superlens 110 may have positive refractive power (e.g., a first positive refractive power), the second superlens 120 may have negative refractive power, and the third superlens 130 may have positive refractive power (e.g., a second positive refractive power). Lenses with positive refractive power are based on the principle of a convex lens with a positive focal length and can allow light incident parallel to the optical axis OI to pass through, thus focusing the light. On the other hand, lenses with negative refractive power are based on the principle of a concave lens and can allow parallel incident light to pass through, thus diverging the light.

[0067] The first superlens 110, the second superlens 120, and the third superlens 130 may include nanostructures that modulate the phase, polarization, and / or amplitude of the wavelength of incident light. The nanostructures can alter the wavefront of light passing through the first superlens 110, the second superlens 120, and the third superlens 130 to a different wavefront than that of the incident light.

[0068] Figure 2 Shows the phase distribution relative to the radius of each of the first superlens 110, the second superlens 120, and the third superlens 130. A represents the phase distribution of the first superlens 110, B represents the phase distribution of the second superlens 120, and C represents the phase distribution of the third superlens 130. The first superlens 110 may have a positive refractive power and a phase distribution convex upward. The second superlens 120 may have a negative refractive power and a phase distribution convex downward. The third superlens 130 may have a positive refractive power and a phase distribution convex upward. The second superlens 120 may have a phase distribution convex downward in the main part and a phase distribution convex upward in the edge part 120M. Thus, the second superlens 120 may have an inflection point and have a negative refractive power in the main part and a positive refractive power in the edge part. The third superlens 130 may have a phase distribution convex upward in the main part and a phase distribution convex downward in the edge part 130M. Thus, the third superlens 130 may have an inflection point and have a positive refractive power in the main part and a negative refractive power in the edge part. The inflection point may represent a point where the phase distribution changes from convex to concave or a point where the phase distribution changes from concave to convex. The inflection point may be between the 1 / 2 point (e.g., the midpoint) of the radius of the superlens and the edge of the superlens.

[0069] The superlens assembly 100 according to an embodiment of the present disclosure may implement a wide-angle imaging system. The superlens assembly 100 may have a viewing angle of about 40 degrees to about 80 degrees. In other words, the angular range of the object imaged by the superlens assembly 100 may have a value between about 40 degrees and about 80 degrees. The diameter D1 (e.g., the first diameter) of the first superlens 110 and the diameter D2 (e.g., the second diameter) of the second superlens 120 may both be smaller than the diameter D3 (e.g., the third diameter) of the third superlens 130. For example, D1 < D2 < D3. The diameter D1 of the first superlens 110, the diameter D2 of the second superlens 120, and the diameter D3 of the third superlens 130 may all be smaller than about 1 mm. The first superlens 110, the second superlens 120, and the third superlens 130 may all have a diameter smaller than the diagonal length of the image sensor 150.

[0070] The distance d1 between the first superlens 110 and the second superlens 120 can be in the range of about 10 μm to about 100 μm. The distance d1 between the first superlens 110 and the second superlens 120 can represent the distance between the incident surface 110a of the first superlens 110 and the incident surface 120a of the second superlens 120. The distance d2 between the second superlens 120 and the third superlens 130 can be in the range of about 100 µm to about 600 µm. The distance d2 can represent the distance between the incident surface 120a of the second superlens 120 and the incident surface 130a of the third superlens 130. For example, the interval between the first superlens 110 and the second superlens 120 can be less than or equal to 1 / 5 of the interval between the second superlens 120 and the third superlens 130. The TTL from the incident surface 110a of the first superlens 110 to the image sensor 150 can be less than or equal to about 1.7 mm.

[0071] Figure 3 An example of a superlens is shown. The superlens ML1 may include multiple nanostructures NP. In the superlens ML1, the nanostructures NP can be arranged such that their dimensions gradually decrease from the center of the lens. The superlens ML1 may include multiple regions Z in the radial direction r, and the pattern of gradually decreasing dimensions may be repeated for each region Z. When the superlens ML1 has a phase retardation distribution in each region Z that decreases from the center of the superlens ML1 along the radial direction r, the superlens ML1 can function as a convex lens. The width of region Z can be varied when the phase of the nanostructures NP changes to 2πn (n is an integer). In this paper, the dimensions of the nanostructures NP can represent the width of the nanostructures NP, the spacing between adjacent nanostructures NP, the height of the nanostructures NP, etc.

[0072] Figure 4 Another example of a superlens is shown. The superlens ML2 may include multiple nanostructures NP. In the superlens ML2, the nanostructures NP can be arranged such that their dimensions gradually increase from the center of the superlens ML2 along the radial direction r, and the pattern of gradually increasing dimensions can be repeated for each region Z. When the superlens ML2 has a phase retardation distribution that increases radially from the center of the superlens ML2 in each region Z, the superlens ML2 can be used as a concave lens.

[0073] Figure 5Another example of a superlens is shown. The superlens ML3 may include a first region AA1 and a second region AA2. For each region Z in the first region AA1, an arrangement of nanostructures NP (e.g., a first nanostructure) configured to gradually increase in size from the center of the superlens ML3 along the radial direction r can be repeatedly arranged, and for each region Z in the second region AA2, an arrangement of nanostructures NP (e.g., a second nanostructure) configured to gradually decrease in size along the radial direction r of the superlens ML3 can be repeatedly arranged. The superlens ML3 may have an inflection point where the phase distribution changes from convex to concave. The width of region Z can change when the phase of the nanostructure NP changes to 2πn (n is an integer). For example, the width of region Z can increase or decrease relative to the position of the inflection point. The superlens ML3 may correspond to... Figure 1 The second superlens 120, and the second region AA2 can correspond to Figure 2 The edge portion is 120M.

[0074] Figure 6 Another example of a superlens is shown. The superlens ML4 may include a third region AA3 and a fourth region AA4. For each region Z in the third region AA3, an arrangement of nanostructures NP (e.g., a third nanostructure) configured to gradually decrease in size from the center of the superlens ML4 along the radial direction r can be repeated, and for each region Z in the fourth region AA4, an arrangement of nanostructures NP (e.g., a fourth nanostructure) configured to gradually increase in size from the center of the superlens ML4 along the radial direction r can be repeated. The superlens ML4 may correspond to... Figure 1 The third superlens 130, and the fourth region AA4 can correspond to Figure 2 The edge portion is 130M.

[0075] refer to Figure 7 A first transparent substrate 115 may be disposed between a first superlens 110 and a second superlens 120, and a second transparent substrate 125 may be disposed between a second superlens 120 and a third superlens 130. A cover glass 140 may be included between the third superlens 130 and the image sensor 150. The first transparent substrate 115 and the second transparent substrate 125 may support the first superlens 110, the second superlens 120, and the third superlens 130. The lens assembly 100 may also include an aperture 112. The aperture 112 may be in various locations and may be configured in multiple ways. For example, the aperture 112 may surround the first superlens 110 to adjust the amount of light reaching the image forming surface of the image sensor 150. The aperture 112 may be formed of a material that absorbs or reflects light to prevent light from passing through it.

[0076] Figure 8 It shows in Figure 7The illustrated superlens assembly also includes an example of a cover glass. The cover glass 105 may be disposed on the incident surface of the first superlens 110. The cover glass 105 protects the first superlens 110 from external environmental influences and prevents damage to the first superlens 110.

[0077] Figure 9 It shows in Figure 7 The illustrated superlens assembly also includes an example of a third transparent substrate. The third transparent substrate 135 can be disposed on the exit surface of the third superlens 130. The third transparent substrate 135 can support the third superlens 130.

[0078] Figure 10 It shows in Figure 9 An example of the illustrated superlens assembly includes a cover glass 105 on the incident surface of the first superlens 110. In the superlens assembly, the first superlens 110, the second superlens 120, and the third superlens 130 may each include a transparent substrate and a cover glass on the incident and exit surfaces, respectively. The cover glass 105 and the third transparent substrate 135 may each have a thickness of about 0.01 mm to about 0.3 mm. The cover glass 140 may have a thickness of about 0.2 mm to about 0.5 mm. A bandpass filter may also be included between the third superlens 130 and the image sensor 150. The bandpass filter may operate with a bandwidth of about 60 nm relative to the center wavelength of the incident light.

[0079] Superlens assemblies according to various embodiments of this disclosure can be applied to ultra-miniature image sensors. Three superlenses can be stacked to provide a small-sized lens module, thereby enabling a wide-angle imaging system. As the size of image sensors decreases, small-sized lens assemblies corresponding to that size may be required. However, due to limitations such as the minimum thickness of the lens edges and the spacing between lenses, refractive lens-based optical lens modules may be difficult to apply to small-sized camera module packages. By including ultra-thin superlenses with a thickness of several µm or less, superlenses can be stacked based on wafer-level processes, thereby enabling imaging systems that are not limited by the size of refractive lenses. Superlens assemblies according to embodiments of this disclosure can satisfy various details of imaging systems (F-number, field of view (FOV), TTL, modulation transfer function (MTF), distortion, refractive index (RI), etc.). Superlens assemblies according to embodiments of this disclosure can have an effective focal length of about 1 mm or less and can achieve a bright lens with an F-number of about 2.2 or less. The optical distortion and TV distortion of superlens assemblies according to embodiments of this disclosure can satisfy |distortion| < 5%. The superlens assembly according to embodiments of this disclosure can operate at a wide angle to capture light with a large principal ray angle, even at the edges of the image sensor, thus satisfying a relative illumination of 1.0F > 40%. 1.0F can represent the maximum height at the center of the image sensor.

[0080] Figure 11A An example of a superlens ML is shown. A superlens ML can include a nanostructure NP. While in Figure 11A The image shows a nanostructure NP disposed in one layer as an example, but the nanostructure NP can also be disposed in two or three layers. The refractive power of the superlens ML can be adjusted by changing the size, spacing, height, etc. of the nanostructure NP.

[0081] Figure 11B This is a perspective view illustrating an example form of a nanostructure that may be employed in a superlens of a lens assembly according to an embodiment of the present disclosure. Reference Figure 11B The nanostructure can have a cylindrical shape with a diameter D and a height H. At least one of the diameter D or the height H can be subwavelength. The diameter D can vary depending on the position of the nanostructure.

[0082] Nanostructures can be formed in the form of columns with various cross-sectional shapes. Figures 12A to 12H This is a plan view illustrating an example form of a nanostructure that may be employed in a superlens of a lens assembly according to an embodiment of the present disclosure.

[0083] like Figure 12A As shown, the cross-sectional shape of the nanostructure can be a ring shape with an outer diameter of D and an inner diameter of Di. The width w of the ring can be subwavelength. Figure 12B As shown, the cross-sectional shape of the nanostructure can be an ellipse with a principal axis length Dx in the first direction x and a secondary axis length Dy in the second direction y (Dx and Dy are different). Figure 12C , Figure 12D and Figure 12F As shown, the cross-sectional shape of the nanostructure can be square, square ring, or cross-shaped. Figure 12E and Figure 12G As shown, the cross-sectional shape of the nanostructure can be a rectangular shape or a cross shape with a principal axis length Dx in the first direction x and a secondary axis length Dy in the second direction y (Dx and Dy are different). Figure 12H As shown, the cross-sectional shape of a nanostructure can be a shape with multiple concave circular arcs.

[0084] Figure 13 This is a vertical cross-sectional view of the superlens 300. Figure 13 An example of arranging nanostructures in two layers is shown. Figure 13 The structure of nanostructures arranged radially r from the center of the superlens 300 is shown. Figure 14A The cross-section of nanostructure 310 is shown in more detail, and Figure 14B and Figure 14C They are respectively along Figure 14AThe horizontal cross-sectional view of lines Y1-Y1' and Y2-Y2'.

[0085] The nanostructure 310 may include a first phase-shifting layer 311, a second phase-shifting layer 315, and a support layer 370. The first phase-shifting layer 311 can respond to light incident on the nanostructure 310 by shifting its phase. The light with the shifted phase can be incident on the second phase-shifting layer 315, which can further shift the phase of the light. Therefore, the incident light can interact with the first phase-shifting layer 311 and the second phase-shifting layer 315 in sequence, and thus can be emitted in a phase-shifted form. Figure 13 and 14A A support layer 370 supporting the first phase shift layer 311 and the second phase shift layer 315 is shown, but the support layer 370 may be omitted.

[0086] Each of the first phase-shifting layer 311 and the second phase-shifting layer 315 may comprise a combination of materials with different refractive indices. Figure 13 and Figure 14A In the embodiments of this disclosure shown, each of the first phase shift layer 311 and the second phase shift layer 315 may have a form in which one material surrounds another material. For example, both the first phase shift layer 311 and the second phase shift layer 315 may include inner pillars and structures surrounding the inner pillars. More specifically, the first phase shift layer 311 may have a hollow structure, for example, a structure surrounding a gas column (e.g., the first inner pillar 311a). On the other hand, the second phase shift layer 315 may have an internally filled structure, for example, a structure of another material surrounding a cylindrical internal material (e.g., the second inner pillar 315a). The structures surrounding the inner pillars of the first phase shift layer 311 and the second phase shift layer 315 may be formed of the same materials, such as dielectrics (SiO2, etc.), glass (fused silica, BK7, etc.), quartz, polymers (polymethyl methacrylate (PMMA), SU-8, etc.), plastics, and / or semiconductor materials. The material of the inner pillars may include crystalline silicon (c-Si), polycrystalline silicon (polycrystalline Si), amorphous silicon (Si), Si3N4, GaP, GaAs, TiX, Alb, Alas, AlGaAs, AlGaInP, BP, and / or ZnGeP2. For example, the inner pillars of the second phase-shifting layer 315 may be formed of TiO2.

[0087] The shape, size, and height of the cross-section of each of the first phase shift layer 311 and the second phase shift layer 315, as well as the shape, size, and height of the cross-section of each of the first inner pillar 311a and the second inner pillar 315a, can be appropriately designed based on the properties of the selected material. For example, the cross-sections of the first phase shift layer 311 and the second phase shift layer 315 can all have shapes such as square, rectangular, parallelogram, regular hexagon, etc. Figure 14B and Figure 14CExamples of square cross-sections are shown. The width w310 of each of the first phase shift layer 311 and the second phase shift layer 315 can be smaller than the wavelength of the incident light. The width w310 of each of the first phase shift layer 311 and the second phase shift layer 315, which is designed to change the phase of visible light, can be less than about 400 nm or about 300 nm (e.g., about 250 nm).

[0088] The cross-section of each of the first inner column 311a and the second inner column 315a can have a square shape, a circular shape, a rectangular shape, a hollow circular shape, a hollow quadrilateral shape, etc., and Figure 14B and Figure 14C An example of a square cross-section is shown. The height h311 of the first inner column 311a and the height h315 of the second inner column 315a can be twice the respective widths w311a and w315a to avoid optical resonance therein. The height h311 of the first inner column 311a and the height h315 of the second inner column 315a can be optimized through repeated simulations based on material properties and manufacturing processes. Although in Figure 14A The heights of the first inner pillar 311a and the second inner pillar 315a are shown to be the same as the heights of the first phase shift layer 311 and the second phase shift layer 315, but the heights of the first inner pillar 311a and the second inner pillar 315a may differ from the heights of the first phase shift layer 311 and the second phase shift layer 315. For example, the heights of the first inner pillar 311a and the second inner pillar 315a may be less than the heights of the first phase shift layer 311 and the second phase shift layer 315. The height h311 of the square first phase shift layer 311 and the first inner pillar 311a, designed to interact with visible light, may be, for example, about 3000 nm, and the height h315 of the second phase shift layer 315 and the second inner pillar 315a may be, for example, about 1500 nm. According to this example, the height h311 of the first phase shift layer 311, which interacts with incident light, may initially be greater than the height h315 of the second phase shift layer 315. A spacer layer may also be included between the first phase shift layer 311 and the second phase shift layer 315 and / or between the first inner pillar 311a and the second inner pillar 315a. Figure 14D An example is shown that includes a spacer layer 390 between the first phase shift layer 311 and the second phase shift layer 315.

[0089] The support layer 370 can support the first phase shift layer 311 and the second phase shift layer 315 and can be formed of dielectric (SiO2, etc.), glass (fused silica, BK7, etc.), quartz, polymer (PMMA, SU-8, etc.), plastic and / or semiconductor materials. The support layer 370 can have a thickness of about 0.1 mm to about 1.0 mm.

[0090] The structure surrounding the first inner pillar 311a of the first phase shift layer 311 and the second inner pillar 315a of the second phase shift layer 315, as well as the support layer 370, can be formed of the same material (e.g., SiO2). The support layer 370 can be formed of a different material than the materials of the structures of the first phase shift layer 311 and the second phase shift layer 315, and can be omitted as described above.

[0091] The lens assembly according to the foregoing exemplary embodiments of this disclosure can be used in various optical devices and electronic devices such as cameras. Electronic devices may be, but are not limited to, smartphones, mobile phones, personal digital assistants (PDAs), laptops, personal computers (PCs), various portable devices, VR, AR, or other mobile or non-mobile computing devices.

[0092] References installed on electronic devices (optical devices, etc.) can be used. Figures 1 to 14D The described lens assembly. The electronic device may also include an image sensor and an application processor (AP), and control multiple hardware or software components connected to the AP via an operating system (OS) or application, performing processing and operations on various data. The AP may also include a graphics processing unit (GPU) and / or an image signal processor. When an image signal processor is included in the AP, images (or videos) acquired by the image sensor can be stored and / or output using the AP.

[0093] Figure 15 This is a block diagram illustrating an example of an electronic device 2201 in a network environment 2200 according to an embodiment of the present disclosure. Reference Figure 15In network environment 2200, electronic device 2201 can communicate with another electronic device 2202 via a first network 2298 (e.g., a short-range wireless communication network), or with another electronic device 2204 or server 2208 via a second network 2299 (e.g., a long-range wireless communication network). Electronic device 2201 can communicate with electronic device 2204 via server 2208. Electronic device 2201 may include processor 2220, memory 2230, input device 2250, sound output device 2255, display device 2260, audio module 2270, sensor module 2276, interface 2277, haptic module 2279, camera module 2280, power management module 2288, battery 2289, communication module 2290, subscriber identification module 2296, and / or antenna module 2297. Some components (e.g., display device 2260, etc.) may be omitted from electronic device 2201, or other components may be added to electronic device 2201. Some components of the assembly can be implemented as a single integrated circuit. For example, sensor module 2276 (e.g., fingerprint sensor, iris sensor, or illuminance sensor) can be implemented as an embedded component in display device 2260 (e.g., display, etc.).

[0094] Processor 2220 can execute software (e.g., program 2240, etc.) to control one or more different components (e.g., hardware or software components, etc.) coupled to processor 2220, and can perform various data processing or calculations. As part of data processing or calculation, processor 2220 can load commands or data received from another component (e.g., sensor module 2276, communication module 2290, etc.) into volatile memory 2232, process the commands and / or data stored in volatile memory 2232, and store the resulting data in non-volatile memory 2234. Non-volatile memory 2234 may include internal memory 2236 and external memory 2238. Processor 2220 may include a main processor 2221 (e.g., central processing unit (CPU), AP, etc.) and auxiliary processors 2223 (e.g., graphics processing unit, image signal processor, sensor hub processor, communication processor, etc.) that can operate independently of or in conjunction with the main processor 2221. The secondary processor 2223 can use less power than the main processor 2221 and perform specific functions.

[0095] The auxiliary processor 2223 can replace the main processor 2221 when the main processor 2221 is inactive (e.g., in a sleep state), or, when the main processor 2221 is active (e.g., in an application execution state), work with the main processor 2221 to control the functions and / or states of some components of the electronic device 2201 (e.g., display device 2260, sensor module 2276, communication module 2290, etc.). The auxiliary processor 2223 (e.g., image signal processor, communication processor, etc.) can be implemented as part of another component that is functionally related to it (e.g., camera module 2280, communication module 2290, etc.).

[0096] Memory 2230 may store various data required by components of electronic device 2201 (e.g., processor 2220, sensor module 2276, etc.). This data may include, for example, input and / or output data of software (e.g., program 2240, etc.) and associated commands. Memory 2230 may include volatile memory 2232 and / or non-volatile memory 2234.

[0097] Program 2240 may be stored as software in memory 2230 and may include, for example, an operating system 2242, middleware 2244 and / or application 2246.

[0098] Input device 2250 can receive commands and / or data from outside electronic device 2201 (e.g., a user, etc.) to be used by another component of electronic device 2201 (e.g., processor 2220, etc.). Input device 2250 may include a microphone, mouse, keyboard, and / or digital pen (e.g., stylus, etc.).

[0099] The sound output device 2255 can output sound signals to the outside of the electronic device 2201. The sound output device 2255 may include a speaker and / or a handset. The speaker can be used for general purposes, such as playing multimedia or playing recordings, and the handset can be used for incoming calls. The handset can be coupled as part of the speaker or can be implemented as a separate, independent device.

[0100] Display device 2260 can visually provide information to the outside of electronic device 2201. Display device 2260 may include a display, a holographic device or projector and control circuitry, wherein the control circuitry is used to control a corresponding one of the display, holographic device, and projector. Display device 2260 may include touch circuitry adapted to detect touch and / or sensor circuitry adapted to measure the intensity of the force generated by touch (e.g., pressure sensor, etc.).

[0101] Audio module 2270 can convert sound into electrical signals and vice versa. Audio module 2270 can obtain sound via input device 2250, or output sound via sound output device 2255 and / or another electronic device (e.g., electronic device 2202, etc.) directly (e.g., wired) or wirelessly coupled to electronic device 2201.

[0102] Sensor module 2276 can detect the operating state of electronic device 2201 (e.g., power, temperature, etc.) or the environmental state outside electronic device 2201 (e.g., user state, etc.), and then generate electrical signals and / or data values ​​corresponding to the detected state. Sensor module 2276 may include gesture sensors, gyroscope sensors, atmospheric pressure sensors, magnetic sensors, accelerometers, grip sensors, proximity sensors, color sensors, infrared (IR) sensors, biometric sensors, temperature sensors, humidity sensors, and / or illuminance sensors.

[0103] Interface 2277 may support one or more specified protocols to be used for electronic device 2201 for direct or wireless coupling with another electronic device (e.g., electronic device 2202, etc.). Interface 2277 may include a High Definition Multimedia Interface (HDMI), a Universal Serial Bus (USB) interface, a Secure Digital (SD) card interface, and / or an audio interface.

[0104] Connection terminal 2278 may include a connector via which electronic device 2201 can be physically connected to another electronic device (e.g., electronic device 2202, etc.). Connection terminal 2278 may include, for example, an HDMI connector, a USB connector, an SD card connector, and / or an audio connector (e.g., a headphone connector, etc.).

[0105] The haptic module 2279 can convert electrical signals into mechanical stimuli (e.g., vibration, movement) or electrical stimuli that can be recognized by a user through his touch or kinesthesia. The haptic module 2279 may include a motor, a piezoelectric element, and / or an electrical stimulator.

[0106] Camera module 2280 can capture still images or moving images. Camera module 2280 may include: a lens assembly comprising one or more lenses, an image sensor, an image signal processor, and / or a flash. The lens assembly included in camera module 2280 can collect light emitted from an object that is the target of image capture, and can be referenced above. Figure 1 , Figure 7 , Figure 8 , Figure 9 and Figure 10 Any one of the lens assemblies 100 described.

[0107] The power management module 2288 can manage the power supplied to the electronic device 2201. The power management module 2288 can be implemented as part of a power management integrated circuit (PMIC).

[0108] Battery 2289 can supply power to components of electronic device 2201. Battery 2289 may include a non-rechargeable primary battery, a rechargeable secondary battery, and / or a fuel cell.

[0109] Communication module 2290 can support the establishment of direct (e.g., wired) and / or wireless communication channels between electronic device 2201 and another electronic device (e.g., electronic device 2202, electronic device 2204, server 2208, etc.), and perform communication via the established communication channels. Communication module 2290 may include one or more communication processors that can operate independently of processor 2220 (e.g., AP, etc.) and support direct and / or wireless communication. Communication module 2290 may include wireless communication module 2292 (e.g., cellular communication module, short-range wireless communication module, Global Navigation Satellite System (GNSS) communication module, etc.) and / or wired communication module 2294 (e.g., local area network (LAN) communication module, power line communication module, etc.). A corresponding communication module among these communication modules can communicate via a first network 2298 (e.g., such as Bluetooth). TM The communication module 2292 communicates with external electronic devices via a short-range communication network (such as Wi-Fi Direct or Infrared Data Association (IrDA)) or a second network 2299 (such as a long-range communication network such as a cellular network, the Internet, or a computer network (e.g., a LAN, a wide area network (WAN), etc.)). These various types of communication modules can be implemented as a single component (e.g., a single chip) or as multiple components separate from each other (e.g., multiple chips). The wireless communication module 2292 can use user information (e.g., International Mobile Subscriber Identity (IMSI)) stored in the subscriber identification module 2296 to identify and authenticate electronic devices 2201 within the communication network (e.g., a first network 2298 and / or a second network 2299).

[0110] Antenna module 2297 can transmit signals and / or power to or from an external source (e.g., another electronic device). The antenna may include a radiator, comprising a conductive pattern formed on a substrate (e.g., a printed circuit board (PCB)). Antenna module 2297 may include one or more antennas. When multiple antennas are included, communication module 2290 can select an antenna suitable for a communication scheme used in a communication network such as a first network 2298 and / or a second network 2299. Signals and / or power can then be transmitted or received between communication module 2290 and another electronic device via the selected antenna. Components other than the antenna (e.g., a radio frequency integrated circuit (RFIC)) may be included as part of antenna module 2297.

[0111] Some of the components mentioned above can be coupled to each other and exchange signals (e.g., commands, data, etc.) between them via peripheral communication schemes (e.g., bus, general purpose input and output (GPIO), serial peripheral interface (SPI), mobile industrial processor interface (MIPI), etc.).

[0112] Commands or data can be sent or received between electronic device 2201 and external electronic device 2204 via server 2208 coupled to the second network 2299. Other electronic devices 2202 and 2204 can be devices of the same or different types as electronic device 2201. All or some operations to be performed at electronic device 2201 can be performed at one or more of the other electronic devices 2202, 2204, and 2208. For example, when electronic device 2201 performs a function or service, instead of performing that function or service itself, it can request one or more other electronic devices to perform the entire function or service or a portion thereof. The one or more other electronic devices receiving the request can perform additional functions or services related to the request and transmit the results of the execution to electronic device 2201. For this purpose, cloud computing, distributed computing, and / or client-server computing technologies can be used, for example.

[0113] Figure 16 It is shown in detail Figure 15 Block diagram of camera module 2280. (Reference) Figure 16 The camera module 2280 may include a lens assembly 2310, a flash 2320, and an image sensor 2330 (e.g., Figure 1 The image sensor 150, etc., image stabilizer 2340, memory 2350 (e.g., buffer memory, etc.), and / or image signal processor 2360. Lens assembly 2310 can collect light emitted from the object that is the target of image capture, and can be referenced on it. Figures 1 to 14DAny of the lens assemblies described. Camera module 2280 may include multiple lens assemblies 2310, and in this case, camera module 2280 may include a dual-camera, a 360-degree camera, or a spherical camera. Some of the multiple lens assemblies 2310 may have the same lens properties (e.g., angle of view, focal length, autofocus, F-number, optical zoom, etc.) or different lens properties. Lens assembly 2310 may include a wide-angle lens or a telephoto lens.

[0114] The flash unit 2320 can emit light to amplify light reflected from an object. The flash unit 2320 may include one or more light-emitting diodes (LEDs) (e.g., red-green-blue (RGB) LEDs, white LEDs, infrared (IR) LEDs, ultraviolet (UV) LEDs, etc.) and / or a xenon lamp. The image sensor 2330 may be a reference. Figure 1 , Figure 5 and Figure 7 The image sensor 150 is described, and can acquire an image corresponding to an object by converting light emitted or reflected from an object and transmitted via lens assembly 2310 into an electrical signal. Image sensor 2330 may include one or more sensors selected from image sensors with different properties (e.g., RGB sensor, black-and-white (BW) sensor, IR sensor, or UV sensor). Each sensor included in image sensor 2330 may be implemented, for example, using a charge-coupled device (CCD) sensor and / or a complementary metal-oxide-semiconductor (CMOS) sensor.

[0115] In response to movement of camera module 2280 or electronics 2201 including camera module 2280, image stabilizer 2340 may move image sensor 2330 or one or more lenses included in lens assembly 2310 in a specific direction, or control operating attributes of image sensor 2330 (e.g., adjust readout timing), thereby compensating for the negative effects of said movement. Image stabilizer 2340 may use a gyroscope sensor or accelerometer sensor disposed inside or outside camera module 2280 to sense movement of camera module 2280 or electronics 2201. Image stabilizer 2340 may be implemented in an optical form.

[0116] The memory 2350 can store all or a portion of the data of the image acquired via the image sensor 2330 for subsequent image processing tasks. For example, when multiple images are acquired rapidly, the raw data (e.g., Bayer pattern data, high-resolution data, etc.) can be stored in the memory 2350, and a low-resolution image can be displayed for use when transmitting the selected image (e.g., an image selected by the user, etc.) to the image signal processor 2360. The memory 2350 can be integrated into the memory 2230 of the electronic device 2201 or can be configured as a separate, independently managed memory.

[0117] Image signal processor 2360 can perform one or more image processing operations on images acquired via image sensor 2330 or image data stored in memory 2350. One or more image processing operations may include depth map generation, 3D modeling, panorama generation, feature point extraction, image compositing, and / or image compensation (e.g., noise reduction, resolution adjustment, brightness adjustment, blurring, sharpening, softening, etc.). Image signal processor 2360 can perform control (e.g., exposure time control, readout timing control, etc.) on components included in camera module 2280 (e.g., image sensor 2330). Images processed by image signal processor 2360 may be stored back in memory 2350 for further processing, or may be provided to external components outside camera module 2280 (e.g., memory 2230, display device 2260, electronic device 2202, electronic device 2204, server 2208, etc.). Image signal processor 2360 may be integrated into processor 2220 or configured as a separate processor independent of processor 2220. When the image signal processor 2360 is configured as a processor separate from the processor 2220, the image processed by the image signal processor 2360 can be displayed on the display device 2260 after further image processing by the processor 2220.

[0118] Electronic device 2201 may include multiple camera modules 2280 with different attributes or functions. In this case, one of the multiple camera modules 2280 may be a wide-angle camera, while another of the multiple camera modules 2280 may be a telephoto camera. Similarly, one of the multiple camera modules 2280 may be a front-facing camera, while another of the multiple camera modules 2280 may be a rear-facing camera.

[0119] Figure 17 An example of a superlens assembly for an AR or VR glasses application according to an embodiment of the present disclosure is shown. The AR glasses 3300 may include: a projection system 3310 for forming an image; and an element 3320 for guiding the image from the projection system 3310 to the user's eyes. Figures 1 to 14D The superlens assembly described.

[0120] Figure 18 An example of a superlens assembly according to an embodiment of the present disclosure is shown for use in a wearable display. The wearable display 3400 may include a reference lens. Figures 1 to 14D The described superlens assembly can be referenced. Figure 15 and Figure 16 The described electronic device implementation.

[0121] Figure 19 An example of a superlens assembly according to an embodiment of the present disclosure is shown for a mobile phone or smartphone application. The smartphone 3500 may include a camera that may include a superlens assembly according to an embodiment of the present disclosure. Electronic devices according to embodiments of the present disclosure can be applied to… Figure 20 The tablet computer or smart tablet computer 3600 shown Figure 21 The laptop computer shown is 3700 or Figure 22 The television (TV) or smart TV 3800 shown. For example, a smartphone 3500 or a smart tablet computer 3600 may include a high-resolution camera. By using a high-resolution camera, depth information of objects in an image can be extracted, image defocus can be adjusted, or objects in an image can be automatically identified. Electronic devices according to embodiments of this disclosure may include a foldable structure, for example, Figure 23 The diagram illustrates a foldable structure 3900 that may include a camera 3920 and a display device 3910. The superlens assembly according to various embodiments of this disclosure can be applied to foldable cameras in mobile phones or smartphones. The superlens assembly can also be applied to various products such as smart refrigerators, security cameras, robots, medical cameras, etc.

[0122] The superlens assembly according to embodiments of this disclosure can control the phase of incident light through a suitable arrangement of nanostructures of different sizes, and the superlens can be used as a lens with positive or negative refractive power. The function of the refractive lens can be designed in two dimensions, and various imaging systems using a single-layer superlens or a combination of multiple superlenses can be proposed.

[0123] It should be understood that the exemplary embodiments described herein should be considered only in a descriptive sense and not for limiting purposes. The description of features or aspects in each embodiment should generally be considered as applicable to other similar features or aspects in other embodiments. Although one or more embodiments have been described with reference to the accompanying drawings, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope defined by the appended claims and their equivalents.

Claims

1. An ultra-lens assembly comprising: a first ultra-lens; a second ultra-lens disposed on an image side of the first ultra-lens; and a third ultra-lens disposed on an image side of the second ultra-lens, wherein the first, second, and third ultra-lenses are arranged from an object side of the ultra-lens assembly to an image side of the ultra-lens assembly facing an image sensor, and wherein a separation between the first ultra-lens and the second ultra-lens is less than or equal to 1 / 5 of a separation between the second ultra-lens and the third ultra-lens, wherein a phase profile of the second ultra-lens has a point of inflection at which the phase profile changes from concave to convex, wherein the first ultra-lens has a first positive refractive power, the second ultra-lens has a negative refractive power, and the third ultra-lens has a second positive refractive power. 2.The ultra-lens assembly of claim 1, wherein the point of inflection of the second ultra-lens is between a midpoint of a radius of the second ultra-lens and an edge of the second ultra-lens. wherein, 3.The ultra-lens assembly of claim 1, wherein a phase profile of the third ultra-lens has a point of inflection at which the phase profile changes from convex to concave. wherein 4.The ultra-lens assembly of claim 3, wherein the point of inflection of the third ultra-lens is between a midpoint of a radius of the third ultra-lens and an edge of the third ultra-lens. wherein an aperture in an edge portion of the first ultra-lens, 5. The metasurface lens assembly of claim 1, further comprising: wherein the aperture comprises a material that absorbs or reflects light, and wherein the aperture defines an area through which light passes through the first ultra-lens. 6.The ultra-lens assembly of claim 1, wherein a first diameter of the first ultra-lens is less than a third diameter of the third ultra-lens, and a second diameter of the second ultra-lens is less than the third diameter of the third ultra-lens. wherein 7.The ultra-lens assembly of claim 1, wherein a separation between the first ultra-lens and the second ultra-lens is in a range of 10 µm to 100 µm. wherein, 8.The ultra-lens assembly of claim 1, wherein a distance from the first ultra-lens to the image sensor is less than or equal to 1.7 mm. wherein 9.The ultra-lens assembly of claim 1, further comprising a cover glass on an object side of the first ultra-lens. 10.The ultra-lens assembly of claim 1, wherein the ultra-lens assembly has a view angle of 40 degrees to 80 degrees. wherein, 11.The ultra-lens assembly of claim 1, further comprising a cover glass between the third ultra-lens and the image sensor. 12.The ultra-lens assembly of claim 1, wherein each of the first, second, and third ultra-lenses comprises a plurality of nanostructures. wherein 13.The ultra-lens assembly of claim 1, further comprising a first transparent substrate between the first ultra-lens and the second ultra-lens, and a second transparent substrate between the second ultra-lens and the third ultra-lens. 14.The ultra-lens assembly of claim 1, wherein the second ultra-lens comprises a first region comprising first nanostructures and a second region comprising second nanostructures, wherein ​ wherein the first nanostructures in the first region are arranged to gradually increase in size along a radial direction of the second superlens, and wherein the second nanostructures in the second region are arranged to gradually decrease in size along a radial direction of the second superlens.

15. The superlens assembly of claim 1, wherein the third superlens includes a third region including third nanostructures and a fourth region including fourth nanostructures, wherein the third nanostructures in the third region are arranged to gradually decrease in size along a radial direction of the third superlens, and wherein the fourth nanostructures in the fourth region are arranged to gradually increase in size along a radial direction of the third superlens.

16. An electronic device comprising: a superlens assembly in which a plurality of superlenses are arranged from an object side of the superlens assembly to an image side of the superlens assembly; an image sensor that detects an image of an object based on incident light that sequentially passes through the plurality of superlenses; and an image signal processor that stores or outputs the image, wherein the superlens assembly includes: a first superlens; a second superlens arranged on the image side of the first superlens; and a third superlens arranged on the image side of the second superlens, wherein the first superlens, the second superlens, and the third superlens are arranged facing the image sensor from the object side of the superlens assembly to the image side of the superlens assembly, and wherein a separation between the first superlens and the second superlens is less than or equal to 1 / 5 of a separation between the second superlens and the third superlens, wherein a phase distribution of the second superlens has an inflection point at which the phase distribution changes from concave to convex, wherein the first superlens has a first positive refractive power, the second superlens has a negative refractive power, and the third superlens has a second positive refractive power.

17. The electronic device of claim 16, wherein, the inflection point of the second superlens is between a midpoint of a radius of the second superlens and an edge of the second superlens.

18. The electronic device of claim 16, wherein, a phase distribution of the third superlens has an inflection point at which the phase distribution changes from convex to concave.

19. The electronic device of claim 18, wherein, the inflection point of the third superlens is between a midpoint of a radius of the third superlens and an edge of the third superlens.

20. The electronic device of claim 16, further comprising: an aperture in an edge portion of the first superlens, wherein the aperture includes a material that absorbs or reflects light, and wherein the aperture defines an area through which light passes the first superlens.

21. A camera comprising: a superlens assembly according to any one of claims 1 to 15; and an image sensor; wherein a distance from an incident surface of the camera to the image sensor is less than or equal to 1.7 mm, and wherein an angle of view of the camera is between 40 degrees and 80 degrees.

Images