Patent Description:
A greater number of details are usually recognized at the center of the field of view (FOV) of the human vision system, while at the periphery of the FOV only moving objects may be usually monitored. This ability corresponds to a higher-angular resolution at the center of the FOV of human vision and a lower-angular resolution at the periphery. In contrast, image sensors and cameras typically have a constant spatial/angular resolution for the entire FOV of the device. If the resolution of an image sensor or camera is high, the power consumed by reading out sensed image data and by processing the image data may be higher than necessary. A camera having a fisheye lens has very wide FOV; however, the spatial resolution at the center of the fisheye lens is low, which reduces the accuracy of object detection. Consequently, a very wide FOV for an image sensor or camera may not be the best overall solution.

<CIT> discloses: An imaging device has an opaque planar sheet with a plurality of pinholes defining a photon sieve in the sheet, wherein, the photon sieve comprises at least first and second regions. The first region exhibits a first focal length, a first field of view, a first transmissivity, a first resolution and a first wavelength, and the second region exhibiting a second focal length, a second field of view, a second transmissivity, a second resolution and a second wavelength. At least one of the first focal length, the first wavelength, the first transmissivity, the first resolution and the first field of view is different from the second focal length, the second wavelength, the second transmissivity, the second resolution and the second field of view.

<NPL>, discloses metalens-based miniaturized optical systems.

<NPL>, discloses a reprogrammable multifocal THz metalens based on metal-insulator transition of VO2-assisted digital metasurface.

In the following section, the aspects of the subject matter disclosed herein will be described with reference to exemplary embodiments illustrated in the figure, in which:.

In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the disclosure. It will be understood, however, by those skilled in the art that the disclosed aspects may be practiced without these specific details. In other instances, well-known methods, procedures, components and circuits have not been described in detail not to obscure the subject matter disclosed herein.

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment disclosed herein. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" or "according to one embodiment" (or other phrases having similar import) in various places throughout this specification may not be necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments. In this regard, as used herein, the word "exemplary" means "serving as an example, instance, or illustration. " Any embodiment described herein as "exemplary" is not to be construed as necessarily preferred or advantageous over other embodiments. Additionally, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Also, depending on the context of discussion herein, a singular term may include the corresponding plural forms and a plural term may include the corresponding singular form. Similarly, a hyphenated term (e.g., "two-dimensional," "predetermined," "pixel-specific," etc.) may be occasionally interchangeably used with a corresponding non-hyphenated version (e.g., "two dimensional," "predetermined," "pixel specific," etc.), and a capitalized entry (e.g., "Counter Clock," "Row Select," "PIXOUT," etc.) may be interchangeably used with a corresponding non-capitalized version (e.g., "counter clock," "row select," "pixout," etc.). Such occasional interchangeable uses shall not be considered inconsistent with each other.

Also, depending on the context of discussion herein, a singular term may include the corresponding plural forms and a plural term may include the corresponding singular form. It is further noted that various figures (including component diagrams) shown and discussed herein are for illustrative purpose only, and are not drawn to scale. Similarly, various waveforms and timing diagrams are shown for illustrative purpose only. Further, if considered appropriate, reference numerals have been repeated among the figures to indicate corresponding and/or analogous elements.

The terminology used herein is for the purpose of describing some example embodiments only and is not intended to be limiting of the claimed subject matter. The terms "first," "second," etc., as used herein, are used as labels for nouns that they precede, and do not imply any type of ordering (e.g., spatial, temporal, logical, etc.) unless explicitly defined as such. Furthermore, the same reference numerals may be used across two or more figures to refer to parts, components, blocks, circuits, units, or modules having the same or similar functionality. Such usage is, however, for simplicity of illustration and ease of discussion only; it does not imply that the construction or architectural details of such components or units are the same across all embodiments or such commonly-referenced parts/modules are the only way to implement some of the example embodiments disclosed herein.

It will be understood that when an element or layer is referred to as being on, "connected to" or "coupled to" another element or layer, it can be directly on, connected or coupled to the other element or layer or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly connected to" or "directly coupled to" another element or layer, there are no intervening elements or layers present.

The terms "first," "second," etc., as used herein, are used as labels for nouns that they precede, and do not imply any type of ordering (e.g., spatial, temporal, logical, etc.) unless explicitly defined as such. Furthermore, the same reference numerals may be used across two or more figures to refer to parts, components, blocks, circuits, units, or modules having the same or similar functionality. Such usage is, however, for simplicity of illustration and ease of discussion only; it does not imply that the construction or architectural details of such components or units are the same across all embodiments or such commonly-referenced parts/modules are the only way to implement some of the example embodiments disclosed herein.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this subject matter belongs.

As used herein, the term "module" refers to any combination of software, firmware and/or hardware configured to provide the functionality described herein in connection with a module. For example, software may be embodied as a software package, code and/or instruction set or instructions, and the term "hardware," as used in any implementation described herein, may include, for example, singly or in any combination, an assembly, hardwired circuitry, programmable circuitry, state machine circuitry, and/or firmware that stores instructions executed by programmable circuitry. The modules may, collectively or individually, be embodied as circuitry that forms part of a larger system, for example, but not limited to, an integrated circuit (IC), system on-chip (SoC), an assembly, and so forth.

The subject matter disclosed herein provides a progressive metalens for an imaging or a camera system. In one embodiment, a progressive metalens may have different focal lengths and FOVs at different areas of the metalens. For example, the angular resolution at the sides, or periphery, of the metalens may be compressed while the center of the metalens has a high resolution. That is, the center portion of the progressive metalens may have a relatively longer focal length and narrower FOV, while side portions may have shorter focal length and wider FOV.

In one embodiment, the progressive metalens disclosed herein may provide a near-field FOV having a relatively enlarged FOV with lower spatial resolution, while also providing a far-field FOV having a higher spatial resolution and lower FOV. The progressive lens disclosed herein may allow a larger FOV to be monitored for object detection, while also allowing a lower sensor-spatial resolution having a reduced processing power.

The progressive metalens disclosed herein may provide an improved object detection for a far field FOV while still being able to monitor a wider range of a near-field FOV. The progressive metalens disclosed herein may be used in Advanced Driver Assist Systems (ADASs), a smartphone, a camera, a mobile telephone, industrial applications, robotic applications, etc., and may cover a combined large FOV so that many objects in a scene may be tracked.

The progressive metalens disclosed herein may be flexibly designed for different applications. The progressive metalens may include a single, a dual or more layers of nanostructures or a set of repeating nanostructures to vary the FOV spatially along the metalens. In one embodiment, the progressive metalens disclosed herein may include discrete steps for different focal lengths, while in another embodiment, the progressive metalens may include a generally continuously changed focal length. In one embodiment, the progressive lens disclosed herein may be implemented using a nanophotonic fabrication technique on a flat or a curved substrate surface.

<FIG> shows an example FOV that may be seen by a driver of a vehicle. <FIG> depicts an example arrangement <NUM> of different FOVs that may correspond to the view of <FIG> and that be used for an image sensor using a progressive metalens according to the subject matter disclosed herein. The arrangement <NUM> may include one or more regions of FOVs <NUM>-<NUM>. A distant FOV region <NUM> may provide a relatively longer focal length and a relatively narrow FOV. An intermediate FOV region <NUM> may provide a shorter focal length and a wider FOV than provided by the distant FOV region(s) <NUM>. A near FOV region <NUM> may provide a relative short focal length and a relatively wide FOV. In one embodiment, the FOV arrangement <NUM> may be used by an imaging system to cover a large near field FOV (i.e., the near FOV region <NUM>) while providing improved spatial resolution for intermediate and near FOVs (i.e., the intermediate and near FOV regions <NUM> and <NUM>), and a high resolution for a far-field FOV (i.e., the distant FOV region <NUM>). In one embodiment, a progressive metalens may include FOV regions that correspond to the regions <NUM>-<NUM> of the arrangement <NUM> by having sub-lens regions that may change in discrete steps or gradually across the metalens.

<FIG> depicts another example how a progressive metalens may change an FOV across an image plane of an image sensor. At the top right of <FIG>, an example FOV is shown that may be seen by a driver of a vehicle. At the top left of <FIG>, a portion of a focal plane <NUM> of a metalens (not shown) is shown with respect to an image plane <NUM> of an image sensor (also not shown). The focal plane <NUM> is parallel to the image seen by the driver of the vehicle (and the point of view of <FIG>), whereas the image plane <NUM> has an angle to the focal plane <NUM>. Consequently, the point of view causes the image plane <NUM> to appear to be a trapezoidal shape.

At bottom left of <FIG>, the portion of the focal plane <NUM> and the image plane <NUM> are depicted in which the image plane <NUM> is being viewed from the point of view of <FIG> (i.e., perpendicularly from (i.e., normal to) the surface of the image plane <NUM> (and the sheet of the page)). From this point of view, the focal plane <NUM> in <FIG> appears to be trapezoidally shaped. The focal plane of a progressive metalens may be arranged based on the focal plane <NUM> in <FIG>. At the bottom right of <FIG>, an image is shown that is focused on the image plane <NUM> by a progressive metalens arranged based on the focal plane <NUM> in <FIG>. Distortions in the image at the image plane that may be caused by a progressive metalens may be seen.

<FIG> depicts an example embodiment of a progressive metalens <NUM> according to the subject matter disclosed herein. The metalens <NUM> may include one or more layers of nanostructures <NUM> formed on a substrate <NUM>, such as glass or another transparent substrate, such as plastic or any low index organic/inorganic materials that are optically transparent in visible-NIR (<NUM>-<NUM>). The nanostructures <NUM> may be referred to herein as scatterers and/or nanoantennas. The substrate <NUM> for the metalens <NUM> may be flat or curved, and may be formed as, for example, a cover for a sensor chip <NUM>, may be formed as part of a main lens assembly (not shown), or, as depicted in <FIG>, as a separate piece. In one embodiment, the metalens <NUM> may be module, or assembly, that is part of an optical stack of, for example, an imaging system or a camera.

The metalens <NUM> may diffract and/or focus incident light <NUM> onto a pixel array <NUM> on the sensor chip <NUM>. In one embodiment, the pixel array <NUM> may include an optional microlens <NUM>. The pixel array <NUM> may be a single pixel array or multiple pixel arrays arranged to receive light diffracted and/or focused by the metalens <NUM>. In one embodiment, the pixel array <NUM> may be one or more individual 2D and 3D pixel arrays. In another embodiment, the pixel array <NUM> may be one or more hybrid 2D and 3D pixel arrays. Peripheral components <NUM> that support the pixel arrays may also be formed on the sensor chip <NUM>.

<FIG> depicts a top view of an example metalens <NUM> showing that a metalens may have a shape that may be adapted to provide FOVs for any application. Locations of nanostructures <NUM> on the metalens <NUM> may also be adapted to provide one or more FOVs for any application.

<FIG> are graphs respectively showing general diffraction and/or focusing of light by example shaped metalenses. A unit of the abscissa and the ordinate of each of <FIG> is millimeter. <FIG> shows the general diffraction/focusing characteristics of a plano-convex-shaped metalens. <FIG> shows the general diffraction/focusing characteristics of a flat metalens. <FIG> shows the general diffraction/focusing characteristics of an aplanatic metalens. In <FIG>, light is incident upon a main lens <NUM> and the metalens 502a-502c from the left and is diffracted/focused to the right.

<FIG> depict another example arrangement of focal lengths for a metalens according to the subject matter disclosed herein. <FIG> depicts an example arrangement <NUM> of different FOVs that be used for an image sensor using a progressive metalens according to the subject matter disclosed herein. The arrangement <NUM> corresponds to the arrangement <NUM> in <FIG>.

<FIG> depicts diffraction/focusing of light by a progressive metalens onto an image plane of an image sensor. A first region <NUM> of the image plane may correspond to a relatively longer focal length and a relatively narrow FOV (i.e., a "distant" region of the arrangement <NUM>). A second region <NUM> of the image plane may correspond to a shorter focal length and a wider FOV (i.e., an "intermediate" region of the arrangement <NUM>) than the first region <NUM>. A third region <NUM> of the image plane may correspond to a relative short focal length and a relatively wide FOV (i.e., a "near" region of the arrangement <NUM>). <FIG> depicts the three FOV regions including distortions that may be added by the progressive metalens.

<FIG> depicts an example radial arrangement of focal lengths for a circularly shaped progressive metalens <NUM> according to the subject matter disclosed herein. A near focal-length region <NUM> may be arranged around the outside of a circularly shaped metalens <NUM>. An intermediate focal-length region <NUM> may be arranged inside of the near focal-length region <NUM>. A distant focal-length region <NUM> may be arranged near the center of the circularly shaped metalens <NUM>. The shapes of the individual regions <NUM>-<NUM> may be any size to tune the horizontal and vertical (H x V) angular resolution of an image sensor (not shown). The global shape may be any shape to tune the FOV spatially.

In the embodiment depicted in <FIG>, the intermediate focal-length region <NUM> may be surrounded by the near focal-length region <NUM>, and the distant focal-length region <NUM> may be surrounded by the intermediate focal-length region <NUM>. In other embodiments, the size and shape of the different regions may be selected based on the application. Additionally, in other embodiments, any number of different focal-length regions may be used.

<FIG> depicts an example arrangement <NUM> of nanostructures that corresponds to the radial arrangement depicted in <FIG>. Images <NUM>-<NUM> respectively depict phases of an image at an image plane corresponding to the individual regions <NUM>-<NUM>.

<FIG> depicts example radial arrangement of focal lengths for a circularly shaped progressive metalens <NUM> depicted in <FIG> according to the subject matter disclosed herein. The different shades of gray correspond to different focal lengths. The nanostructures <NUM> formed on a metalens <NUM> focus the incident light <NUM> at different locations on an image plane <NUM>.

<FIG> depicts how nanostructures <NUM> may be configured as single or dual layers on one or more substrates 800a-800c of the circularly shaped progressive metalens <NUM> of <FIG> to control the FOVs spatially according to the subject matter disclosed herein. The different shades of gray correspond to different focal lengths.

<FIG> depicts an electronic device <NUM> that includes an imaging system that includes a progressive metalens may have different focal lengths and FOVs at different areas of the metalens according to the subject matter disclosed herein. Electronic device <NUM> may be used in, but not limited to, a computing device, a personal digital assistant (PDA), a laptop computer, a mobile computer, a web tablet, a wireless phone, a cell phone, a smart phone, a digital music player, or a wireline or wireless electronic device. The electronic device <NUM> may also be part of, but not limited to, an ADAS, a mobile-device imaging system, an industrial imaging system, robotics, etc. The electronic device <NUM> may include a controller <NUM>, an input/output device <NUM> such as, but not limited to, a keypad, a keyboard, a display, a touch-screen display, a camera, and/or an image sensor, a memory <NUM>, an interface <NUM>, a GPU <NUM>, and an image processing unit <NUM> that are coupled to each other through a bus <NUM>. The controller <NUM> may include, for example, at least one microprocessor, at least one digital signal processor, at least one microcontroller, or the like. The memory <NUM> may be configured to store a command code to be used by the controller <NUM> or a user data.

Electronic device <NUM> and the various system components of electronic device <NUM> may include the image processing unit <NUM>. In one embodiment, the image processing unit <NUM> may be part of an imaging system that includes a progressive metalens. The progressive metalens may have different focal lengths and FOVs at different areas of the metalens according to the subject matter disclosed herein. The interface <NUM> may be configured to include a wireless interface that is configured to transmit data to or receive data from a wireless communication network using a RF signal. The wireless interface <NUM> may include, for example, an antenna, a wireless transceiver and so on. The electronic device <NUM> also may be used in a communication interface protocol of a communication system, such as, but not limited to, Code Division Multiple Access (CDMA), Global System for Mobile Communications (GSM), North American Digital Communications (NADC), Extended Time Division Multiple Access (E-TDMA), Wideband CDMA (WCDMA), CDMA2000, Wi-Fi, Municipal Wi-Fi (Muni Wi-Fi), Bluetooth, Digital Enhanced Cordless Telecommunications (DECT), Wireless Universal Serial Bus (Wireless USB), Fast low-latency access with seamless handoff Orthogonal Frequency Division Multiplexing (Flash-OFDM), IEEE <NUM>, General Packet Radio Service (GPRS), iBurst, Wireless Broadband (WiBro), WiMAX, WiMAX-Advanced, Universal Mobile Telecommunication Service - Time Division Duplex (UMTS-TDD), High Speed Packet Access (HSPA), Evolution Data Optimized (EVDO), Long Term Evolution - Advanced (LTE-Advanced), Multichannel Multipoint Distribution Service (MMDS), and so forth.

Embodiments of the subject matter and the operations described in this specification may be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed in this specification and their structural equivalents, or in combinations of one or more of them. Embodiments of the subject matter described in this specification may be implemented as one or more computer programs, i.e., one or more modules of computer-program instructions, encoded on computer-storage medium for execution by, or to control the operation of, data-processing apparatus. A computer-storage medium can be, or be included in, a computer-readable storage device, a computer-readable storage substrate, a random or serial-access memory array or device, or a combination thereof. Moreover, while a computer-storage medium is not a propagated signal, a computer-storage medium may be a source or destination of computer-program instructions encoded in an artificially-generated propagated signal. The computer-storage medium can also be, or be included in, one or more separate physical components or media (e.g., multiple CDs, disks, or other storage devices). Additionally, the operations described in this specification may be implemented as operations performed by a data-processing apparatus on data stored on one or more computer-readable storage devices or received from other sources.

While this specification may contain many specific implementation details, the implementation details should not be construed as limitations on the scope of any claimed subject matter, but rather be construed as descriptions of features specific to particular embodiments. Certain features that are described in this specification in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable subcombination.

Claim 1:
A metalens (<NUM>, <NUM>, <NUM>, <NUM>), comprising:
a first region (<NUM>) of nanostructures (<NUM>, <NUM>, <NUM>) that directs a first field of view, FOV, of light (<NUM>, <NUM>) incident on the first region (<NUM>) of nanostructures (<NUM>, <NUM>, <NUM>) to a first region (<NUM>) of an image plane (<NUM>, <NUM>); and
a second region (<NUM>) of nanostructures (<NUM>, <NUM>, <NUM>) that directs a second FOV of light (<NUM>, <NUM>) incident on the second region (<NUM>) of nanostructures (<NUM>, <NUM>, <NUM>) to a second region (<NUM>) of the image plane (<NUM>, <NUM>), the second FOV being different from the first FOV, and the second region (<NUM>) of the image plane (<NUM>, <NUM>) being different from the first region (<NUM>) of the image plane (<NUM>, <NUM>),
wherein the first region (<NUM>) of nanostructures (<NUM>, <NUM>, <NUM>) comprises a single layer of nanostructures (<NUM>, <NUM>, <NUM>) formed on a substrate (<NUM>, 800a-c) and wherein the second region (<NUM>) of nanostructures (<NUM>, <NUM>, <NUM>) comprises a dual layer of nanostructures (<NUM>, <NUM>, <NUM>) formed on the substrate (<NUM>, 800a-c), and
wherein nanostructures (<NUM>, <NUM>, <NUM>) of the first region (<NUM>) of nanostructures (<NUM>, <NUM>, <NUM>) are formed on a first surface of the substrate (<NUM>, 800a-c), and nanostructures (<NUM>, <NUM>, <NUM>) of the second region (<NUM>) of nanostructures (<NUM>, <NUM>, <NUM>) are formed on the first surface and a second surface of the substrate (<NUM>, 800a-c), the second surface being opposite the first surface.