PATENT DOCUMENT

Publication Number: US-11061213-B2
Application Number: US-201916264463-A
Country: US
Kind Code: B2

Title: Folded camera

Abstract:
A folded camera that includes two light folding elements such as prisms and an independent lens system, located between the two prisms, which includes an aperture stop and a lens stack. The lens system may be moved on one or more axes independently of the prisms to provide autofocus and/or optical image stabilization for the camera. The shapes, materials, and arrangements of the refractive lens elements in the lens stack may be selected to capture high resolution, high quality images while providing a sufficiently long back focal length to accommodate the second prism.

Claims:
What is claimed is: 
     
       1. An optical system, comprising:
 a first light folding element; 
 a second light folding element; and 
 a lens system located between the first light folding element and the second light folding element, wherein the lens system includes a front aperture stop and a lens stack having four or five refractive lens elements, wherein a second lens element of the lens stack in order from an object side of the lens system to an image side of the lens system has positive refractive power and a concave image-side surface; 
 wherein the first light folding element redirects light from an object field from a first axis to the lens system on a second axis; 
 wherein the lens elements in the lens stack receive the light through the aperture stop and refract the light to the second light folding element; 
 wherein the second light folding element redirects the light from the second axis onto a third axis to form an image of the object field at an image plane; and 
 wherein the lens system is movable on two or more axes independently of the first and second light folding elements. 
 
     
     
       2. The optical system as recited in  claim 1 , wherein the first and second light folding elements are prisms. 
     
     
       3. The optical system as recited in  claim 1 , wherein the lens system is movable on the second axis to provide autofocus functionality for the optical system. 
     
     
       4. The optical system as recited in  claim 1 , wherein the lens system is movable on one or more axes orthogonal to the second axis to provide optical image stabilization functionality for the optical system. 
     
     
       5. The optical system as recited in  claim 1 , wherein one or both of the light folding elements can be translated with respect to the second axis independently of the lens system. 
     
     
       6. The optical system as recited in  claim 1 , wherein one or both of the light folding elements can be tilted with respect to the second axis independently of the lens system. 
     
     
       7. The optical system as recited in  claim 1 , wherein the lens stack consists of four lens elements with refractive power, in order from the object side of the lens system to the image side of the lens system:
 a first lens element with positive refractive power for converging light; 
 the second lens element with positive refractive power for converging light; 
 a third lens element with negative refractive power and an aspheric shape to correct chromatic aberration and field curvature; and 
 a fourth lens element with a meniscus shape to correct field curvature; 
 wherein F-number of the lens system is less than or equal to 2.4, and wherein the lens system provides a long back focal length to accommodate the second light folding element. 
 
     
     
       8. The optical system as recited in  claim 1 , wherein the lens stack consists of five lens elements with refractive power, in order from the object side of the lens system to the image side of the lens system:
 a first lens element with positive refractive power for converging light; 
 the second lens element with positive refractive power for converging light; 
 a third lens element with negative refractive power and an aspheric shape to correct chromatic aberration and field curvature; 
 a fourth lens element with an aspheric shape configured as an air-space doublet with the third lens element to correct chromatic aberration and field curvature; and 
 a fifth lens element with a meniscus shape to correct field curvature; 
 wherein F-number of the lens system is less than or equal to 2.4, and wherein the lens system provides a long back focal length to accommodate the second light folding element. 
 
     
     
       9. An optical system, comprising:
 a first light folding element; 
 a second light folding element; and 
 a lens system located between the first light folding element and the second light folding element, wherein the lens system includes a front aperture stop and a lens stack, wherein the lens stack comprises four lens elements with refractive power, in order from an object side of the lens system to an image side of the lens system:
 a first lens element with positive refractive power and an aspheric shape to control spherical aberration; 
 a second lens element with negative refractive power, a convex object-side surface, and an Abbe number that is less than 30; 
 a third lens element with a meniscus shape that has a concave object-side surface in a paraxial region of the object-side surface and a convex image-side surface in a paraxial region of the image-side surface; and 
 a fourth lens element with a meniscus shape to correct field curvature; 
 wherein F-number of the lens system is less than or equal to 2.4; 
 wherein the first light folding element redirects light from an object field from a first axis to the lens system on a second axis; 
 wherein the lens elements in the lens stack receive the light through the aperture stop and refract the light to the second light folding element; 
 wherein the second light folding element redirects the light from the second axis onto a third axis to form an image of the object field at an image plane; and 
 
 wherein the lens system is movable on two or more axes independently of the first and second light folding elements. 
 
     
     
       10. A camera, comprising:
 a photosensor configured to capture light projected onto a surface of the photosensor; 
 a first light folding element that redirects light received from an object field from a first axis to a second axis; 
 a lens system that includes a front aperture stop and a lens stack having four or five refractive lens elements that refract the light on the second axis, wherein a second lens element of the lens stack in order from an object side of the lens system to an image side of the lens system has positive refractive power and a concave image-side surface; 
 a second light folding element that redirects the light refracted by the lens system from the second axis to a third axis to form an image of the object field at an image plane at or near a surface of the photosensor; and 
 an actuator component configured to move the lens system on two or more axes independently of the first and second light folding elements. 
 
     
     
       11. The camera as recited in  claim 10 , wherein the first and second light folding elements are prisms. 
     
     
       12. The camera as recited in  claim 10 , wherein the lens system is movable on the second axis to provide autofocus functionality for the camera. 
     
     
       13. The camera as recited in  claim 10 , wherein the lens system is movable on one or more axes orthogonal to the second axis to provide optical image stabilization functionality for the camera. 
     
     
       14. The camera as recited in  claim 10 , wherein the camera further includes one or more actuator components configured to translate or tilt one or both of the light folding elements with respect to the second axis independently of the lens system. 
     
     
       15. The camera as recited in  claim 10 , wherein the lens stack consists of four lens elements with refractive power, in order from the object side of the lens system to the image side of the lens system:
 a first lens element with positive refractive power for converging light; 
 the second lens element with positive refractive power for converging light; 
 a third lens element with negative refractive power and an aspheric shape to correct chromatic aberration and field curvature; and 
 a fourth lens element with a meniscus shape to correct field curvature; 
 wherein F-number of the lens system is less than or equal to 2.4, and wherein the lens system provides a long back focal length to accommodate the second light folding element. 
 
     
     
       16. The camera as recited in  claim 10 , wherein the lens stack consists of five lens elements with refractive power, in order from the object side of the lens system to the image side of the lens system:
 a first lens element with positive refractive power for converging light; 
 the second lens element with positive refractive power for converging light; 
 a third lens element with negative refractive power and an aspheric shape to correct chromatic aberration and field curvature; 
 a fourth lens element with an aspheric shape configured as an air-space doublet with the third lens element to correct chromatic aberration and field curvature; and
 a fifth lens element with a meniscus shape to correct field curvature; 
 
 wherein F-number of the lens system is less than or equal to 2.4, and wherein the lens system provides a long back focal length to accommodate the second light folding element. 
 
     
     
       17. A camera, comprising:
 a photosensor configured to capture light projected onto a surface of the photosensor; 
 a first light folding element that redirects light received from an object field from a first axis to a second axis; 
 a lens system that includes a front aperture stop and a lens stack having four refractive lens elements that refract the light on the second axis, wherein the lens stack comprises, in order from the object side of the lens system to the image side of the lens system:
 a first lens element with positive refractive power and an aspheric shape to control spherical aberration; 
 the second lens element with negative refractive power, a convex object-side surface, and an Abbe number that is less than 30; 
 a third lens element with a meniscus shape that has a concave object-side surface in a paraxial region of the object-side surface and a convex image-side surface in a paraxial region of the image-side surface; and 
 a fourth lens element with a meniscus shape to correct field curvature; 
 wherein F-number of the lens system is less than or equal to 2.4; 
 
 a second light folding element that redirects the light refracted by the lens system from the second axis to a third axis to form an image of the object field at an image plane at or near the surface of the photosensor; and 
 an actuator component configured to move the lens system on two or more axes independently of the first and second light folding elements. 
 
     
     
       18. A device, comprising:
 one or more processors; 
 one or more cameras; and 
 a memory comprising program instructions executable by at least one of the one or more processors to control operations of the one or more cameras; 
 wherein at least one of the one or more cameras is a camera comprising:
 a photosensor configured to capture light projected onto a surface of the photosensor; 
 a first light folding element that redirects light received from an object field from a first axis to a second axis; 
 
 a lens system that includes a front aperture stop and a lens stack having four or five refractive lens elements that refract the light on the second axis, wherein a second lens element of the lens stack in order from an object side of the lens system to an image side of the lens system has positive refractive power and a concave image-side surface; 
 a second light folding element that redirects the light refracted by the lens system from the second axis to a third axis to form an image of the object field at an image plane at or near a surface of the photosensor; and 
 an actuator component configured to move the lens system on two or more axes independently of the first and second light folding elements. 
 
     
     
       19. The device as recited in  claim 18 , wherein the lens system is movable on the second axis to provide autofocus functionality for the camera. 
     
     
       20. The device as recited in  claim 18 , wherein the lens system is movable on one or more axes orthogonal to the second axis to provide optical image stabilization functionality for the camera.

Description:
PRIORITY INFORMATION 
     This application claims benefit of priority of U.S. Provisional Application Ser. No. 62/627,645 entitled “FOLDED CAMERA” filed Feb. 7, 2018, the content of which is incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     Technical Field 
     This disclosure relates generally to camera systems, and more specifically to small form factor camera and lens systems. 
     Description of the Related Art 
     The advent of small, mobile multipurpose devices such as smartphones and tablet or pad devices has resulted in a need for high-resolution, small form factor cameras that are lightweight, compact, and capable of capturing high resolution, high quality images at low F-numbers for integration in the devices. However, due to limitations of conventional camera technology, conventional small cameras used in such devices tend to capture images at lower resolutions and/or with lower image quality than can be achieved with larger, higher quality cameras. Achieving higher resolution with small package size cameras generally requires use of a photosensor with small pixel size and a good, compact imaging lens system. Advances in technology have achieved reduction of the pixel size in photosensors. However, as photosensors become more compact and powerful, demand for compact imaging lens systems with improved imaging quality performance has increased. In addition, there are increasing expectations for small form factor cameras to be equipped with higher pixel count and/or larger pixel size image sensors (one or both of which may require larger image sensors) while still maintaining a module height that is compact enough to fit into portable electronic devices. Thus, a challenge from an optical system design point of view is to provide an imaging lens system that is capable of capturing high brightness, high resolution images under the physical constraints imposed by small form factor cameras. 
     SUMMARY OF EMBODIMENTS 
     Embodiments of the present disclosure may provide a folded camera that may, for example, be used in small form factor cameras. Embodiments of a folded camera are described that include two light folding elements (e.g., prisms) and an independent lens system located between the two prisms that includes an aperture stop and lens elements with refractive power mounted in a lens barrel. The prisms and lens system may collectively be referred to as an optical system. The prisms provide a “folded” optical axis for the camera, for example to reduce the Z-height of the camera. The lens system includes a lens stack including one or more refractive lens elements mounted in a lens barrel, and an aperture stop located at or in front of a first lens element in the stack. A first prism redirects light from an object field from a first axis (AX 1) to the lens system on a second axis (AX 2). The lens element(s) in the lens stack receive the light through the aperture stop and refract the light to a second prism that redirects the light onto a third axis (AX 3) on which a photosensor of the camera is disposed. The redirected light forms an image plane at or near the surface of the photosensor. 
     The shapes, materials, and arrangements of the refractive lens elements in the lens stack may be selected to capture high resolution, high quality images while providing a sufficiently long back focal length to accommodate the second prism. Parameters and relationships of the lenses in the lens stack, including but not limited to lens shape, thickness, geometry, position, materials, spacing, and the surface shapes of certain lens elements, may be selected at least in part to reduce, compensate, or correct for optical aberrations and lens artifacts and effects across the field of view. In some embodiments, arrangements of power distribution, lens shapes, prism form factors, and lens materials may be selected to ensure that embodiments of the lens system provide low F-number (e.g., &lt;=2.4), 3× optical zoom, and high resolution imaging. 
     The lens system may be configured in the camera to move on one or more axes independently of the prisms. The camera may include an actuator component configured to move the lens system on (parallel to) the second axis (AX 2) relative to and independently of the prisms to provide autofocus functionality for the camera. In some embodiments, the actuator may instead or also be configured to move the lens system on one or more axes perpendicular to the second axis (AX 2) relative to and independently of the prisms to provide optical image stabilization (OIS) functionality for the camera. In some embodiments, one or both of the prisms may be translated with respect to the second axis (AX 2) independently of the lens system and/or tilted with respect to the second axis (AX 2) independently of the lens system, for example to provide OIS functionality for the camera or to shift the image formed at an image plane at the photosensor. 
     In some embodiments, the lens system may include a lens stack consisting of four lens elements with refractive power, in order from the object side to the image side of the camera: a first lens element with positive refractive power; a second lens element with positive refractive power; a third lens element with negative refractive power and an aspheric shape to correct chromatic aberration and field curvature; and a fourth lens element with a meniscus shape to correct field curvature and provide a low F-number. 
     In some embodiments, the lens system may include a lens stack consisting of five lens elements with refractive power, in order from the object side to the image side of the camera: a first lens element with positive refractive power; a second lens element with positive refractive power; a third lens element with negative refractive power and an aspheric shape to correct chromatic aberration and field curvature; a fourth aspheric lens element configured as an air-space doublet with the third lens element that assists in the aberration correction provided by the third lens element; and a fifth lens element with a meniscus shape to correct field curvature and provide a low F-number. 
     An aperture stop may be located in the lens system at the first lens element for controlling the brightness of the camera. Note that the power order, shape, or other optical characteristics of the refractive lens elements may be different in some embodiments, and some embodiments may include more or fewer refractive lens elements. In some embodiments, the folded camera may include an infrared (IR) filter to reduce or eliminate interference of environmental noise on the photosensor. The IR filter may, for example, be located between the second prism and the photosensor. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  illustrates components of a folded camera with two light folding elements and an independent lens system, according to some embodiments. 
         FIG. 1B  illustrates movements of the lens system relative to the light folding elements in a camera as illustrated in  FIG. 1A , according to some embodiments. 
         FIG. 2  is a cross-sectional illustration of a folded camera with four refractive lens elements in the lens system, according to some embodiments. 
         FIG. 3  is a diagram illustrating a lens system that includes four refractive lens elements, according to some embodiments. 
         FIG. 4A  is a graph illustrating the modulation transfer function (MTF) for a lens system as illustrated in  FIG. 3  at infinity conjugate. 
         FIG. 4B  shows longitudinal spherical aberration, astigmatic field curves, and distortion for a lens system as illustrated in  FIG. 3  at infinity conjugate. 
         FIG. 5A  is a graph illustrating the modulation transfer function (MTF) for a lens system as illustrated in  FIG. 3  at macro conjugate. 
         FIG. 5B  shows longitudinal spherical aberration, astigmatic field curves, and distortion for a lens system as illustrated in  FIG. 3  at macro conjugate. 
         FIG. 6  is a cross-sectional illustration of a folded camera with five refractive lens elements in the lens system, according to some embodiments. 
         FIG. 7  is a diagram illustrating a lens system that includes five refractive lens elements, according to some embodiments. 
         FIG. 8A  is a graph illustrating the modulation transfer function (MTF) for a lens system as illustrated in  FIG. 7  at infinity conjugate. 
         FIG. 8B  shows longitudinal spherical aberration, astigmatic field curves, and distortion for a lens system as illustrated in  FIG. 7  at infinity conjugate. 
         FIG. 9A  is a graph illustrating the modulation transfer function (MTF) for a lens system as illustrated in  FIG. 7  at macro conjugate. 
         FIG. 9B  shows longitudinal spherical aberration, astigmatic field curves, and distortion for a lens system as illustrated in  FIG. 7  at macro conjugate. 
         FIG. 10  is a diagram illustrating a lens system that includes four refractive lens elements, according to some embodiments. 
         FIG. 11A  is a graph illustrating the modulation transfer function (MTF) for a lens system as illustrated in  FIG. 10 . 
         FIG. 11B  shows longitudinal spherical aberration, astigmatic field curves, and distortion for a lens system as illustrated in  FIG. 10 . 
         FIG. 12  is a flowchart of a method for capturing images using embodiments of a camera as illustrated in  FIGS. 1 through 11B , according to some embodiments. 
         FIG. 13  illustrates an example computer system that may be used in embodiments. 
     
    
    
     This specification includes references to “one embodiment” or “an embodiment.” The appearances of the phrases “in one embodiment” or “in an embodiment” do not necessarily refer to the same embodiment. Particular features, structures, or characteristics may be combined in any suitable manner consistent with this disclosure. 
     “Comprising.” This term is open-ended. As used in the appended claims, this term does not foreclose additional structure or steps. Consider a claim that recites: “An apparatus comprising one or more processor units . . . ”. Such a claim does not foreclose the apparatus from including additional components (e.g., a network interface unit, graphics circuitry, etc.). 
     “Configured To.” Various units, circuits, or other components may be described or claimed as “configured to” perform a task or tasks. In such contexts, “configured to” is used to connote structure by indicating that the units/circuits/components include structure (e.g., circuitry) that performs those task or tasks during operation. As such, the unit/circuit/component can be said to be configured to perform the task even when the specified unit/circuit/component is not currently operational (e.g., is not on). The units/circuits/components used with the “configured to” language include hardware—for example, circuits, memory storing program instructions executable to implement the operation, etc. Reciting that a unit/circuit/component is “configured to” perform one or more tasks is expressly intended not to invoke 35 U.S.C. § 112, sixth paragraph, for that unit/circuit/component. Additionally, “configured to” can include generic structure (e.g., generic circuitry) that is manipulated by software and/or firmware (e.g., an FPGA or a general-purpose processor executing software) to operate in manner that is capable of performing the task(s) at issue. “Configure to” may also include adapting a manufacturing process (e.g., a semiconductor fabrication facility) to fabricate devices (e.g., integrated circuits) that are adapted to implement or perform one or more tasks. 
     “First,” “Second,” etc. As used herein, these terms are used as labels for nouns that they precede, and do not imply any type of ordering (e.g., spatial, temporal, logical, etc.). For example, a buffer circuit may be described herein as performing write operations for “first” and “second” values. The terms “first” and “second” do not necessarily imply that the first value must be written before the second value. 
     “Based On.” As used herein, this term is used to describe one or more factors that affect a determination. This term does not foreclose additional factors that may affect a determination. That is, a determination may be solely based on those factors or based, at least in part, on those factors. Consider the phrase “determine A based on B.” While in this case, B is a factor that affects the determination of A, such a phrase does not foreclose the determination of A from also being based on C. In other instances, A may be determined based solely on B. 
     DETAILED DESCRIPTION 
     Embodiments of a folded camera are described that include two light folding elements (e.g., prisms) and an independent lens system located between the two prisms that includes an aperture stop and lens elements with refractive power mounted in a barrel. The prisms and lens system may collectively be referred to as an optical system.  FIG. 1A  illustrates components of a folded camera  100  with two prisms  141  and  142 , and an independent lens system  110 , according to some embodiments. The prisms  141  and  142  provide a “folded” optical axis for the camera  100 , for example to reduce the Z-height of the camera  100 . The lens system  110  includes a lens stack  114  including one or more refractive lens elements mounted in a lens barrel  112 , and an aperture stop  130  located at or in front of a first lens element in the stack  114 . A first prism  141  redirects light from an object field from a first axis (AX 1) to the lens system  110  on a second axis (AX 2). The lens element(s) in the lens stack  114  receive the light through the aperture stop  130  and refract the light to a second prism  142  that redirects the light onto a third axis (AX 3) on which a photosensor  120  of the camera  100  is disposed. The redirected light forms an image at an image plane  121  at or near the surface of the photosensor  120 . 
     The shapes, materials, and arrangements of the refractive lens elements in the lens stack  114  may be selected to capture high resolution, high quality images while providing a sufficiently long back focal length to accommodate the second prism  142 . The camera  100  may, but does not necessarily, include an infrared (IR) filter  150 , for example located between the second prism  142  and the photosensor  120 . 
       FIG. 1B  illustrates movements of the lens system  110  independently of and relative to the prisms  141  and  142  in a camera  100  as illustrated in  FIG. 1A , according to some embodiments. In some embodiments, the camera  100  may include an actuator  160  component or components configured to move the lens system  110  on (parallel to) the second axis (AX 2) relative to and independently of the prisms  141  and  142  to provide autofocus functionality for the camera  100 . In some embodiments, the actuator  160  component(s) may instead or also be configured to move the lens system  110  on one or more axes orthogonal to the second axis (AX 2) relative to and independently of the prisms  141  and  142  to provide optical image stabilization (OIS) functionality for the camera  100 . While not shown, in some embodiments, one or both of the prisms  141  and  142  may be translated with respect to the second axis (AX 2) independently of the lens system  110  and/or tilted with respect to the second axis (AX 2) independently of the lens system  110 , for example to provide OIS functionality for the camera  100  or to shift the image formed at an image plane  121  at the photosensor  120 . 
     Embodiments of a lens system for a folded camera as described herein are configured with a long back focal length (the distance from the last refractive lens element to the image plane) to provide space for a second light folding element (e.g., a second prism). In addition, arrangements of power distribution, lens shapes, prism form factors, and lens materials may be selected to ensure that embodiments of the lens system provide low F-number (e.g., &lt;=2.4), 3× optical zoom, and high resolution imaging. 
     Embodiments of the folded camera as described herein may be implemented in a small package size while still capturing sharp, high-resolution images, making embodiments of the camera suitable for use in small and/or mobile multipurpose devices such as cell phones, smartphones, pad or tablet computing devices, laptop, netbook, notebook, subnotebook, and ultrabook computers, and so on.  FIG. 13  illustrates an example device that may include one or more small form factor cameras that use embodiments of the camera as described herein. However, note that aspects of the camera (e.g., the lens system, prisms, and photosensor) may be scaled up or down to provide cameras with larger or smaller package sizes. In addition, embodiments of the camera may be implemented as stand-alone digital cameras. In addition to still (single frame capture) camera applications, embodiments of the camera may be adapted for use in video camera applications. 
       FIG. 2  is a cross-sectional illustration of a folded camera with four refractive lens elements in the lens system, according to some embodiments.  FIG. 2  shows an example camera  200  including two prisms  241  and  242  that “fold” the optical axis of the camera  200  and an example embodiment of a lens system  210  with four refractive lens elements  201 - 204  located between the prisms  241  and  242 . The lens elements  201 - 204  are mounted in a lens barrel  212 , with an aperture stop  230  located at or in front of the first (object side) lens element  201 . While embodiments are generally described as using prisms to fold the optical axis, other methods may be used to fold the optical axis, including but not limited to mirrors. The first prism  241  folds the optical axis from a first axis (AX 1) that is parallel to the incoming light direction to a second axis (AX 2) that is orthogonal to the incoming light direction. The second prism  242  folds the optical axis from the second axis (AX 2) that is orthogonal to the incoming light direction to a third axis (AX 3) that is parallel to the incoming light direction. 
     The camera  200  also includes a photosensor  220 , and may also include an optional infrared (IR) filter. A camera  200  including an embodiment of the lens system  210  as illustrated in  FIG. 2  may, for example, be implemented in portable electronic devices such as mobile phones and tablets. Embodiments of the lens system  210  may provide a low F-number (&lt;=2.4), 3× optical zoom, and high resolution imaging. 
     In some embodiments, the camera  200  may include an actuator  260  component or components configured to move the lens system  210  on (parallel to) the second axis (AX 2) relative to and independently of the prisms  241  and  242  to provide autofocus functionality for the camera  200 . In some embodiments, the actuator  260  component(s) may instead or also be configured to move the lens system  210  on one or more axes orthogonal to the second axis (AX 2) relative to and independently of the prisms  241  and  242  to provide optical image stabilization (OIS) functionality for the camera  200 . Various types of mechanical, magnetic, or other actuator technology may be used in various embodiments. In some embodiments, one or both of the prisms  241  and  242  may be translated with respect to the second axis (AX 2) independently of the lens system  210  and/or tilted with respect to the second axis (AX 2) independently of the lens system  210 , for example to provide OIS functionality for the camera  200  or to shift the image formed at an image plane  221  at the photosensor  220 . 
     As shown in the example of  FIG. 2 , embodiments of the lens system  210  may include four lens elements  201 - 204  with refractive power. Note, however, that some embodiments may include more or fewer refractive lens elements. Some embodiments of the lens system  210  may provide a 35 mm equivalent focal length in the range of 80-200 mm and less than 6.5 mm of Z-height to fit in a wide variety of portable electronics devices. With proper arrangement of materials and lens powers, embodiments of the lens system  210  are capable of capturing high brightness photographs or video frames with near diffraction-limited image quality. 
     As illustrated in the example camera  200  of  FIG. 2 , the lens system  210  may include four lens elements  201 - 204  with refractive power, in order from the object side to the image side of the camera  200 : a first lens element  201  with positive refractive power; a second lens element  202  with positive refractive power; a third lens element  203  with negative refractive power and an aspheric shape to correct chromatic aberration and field curvature; and a fourth lens element  204  with a meniscus shape to correct field curvature and provide a low F-number. At least one of the refractive lens elements may be formed of lightweight polymer or plastic material. At least two of the refractive lens elements may be formed of materials with different Abbe numbers. An aperture stop  230  may be located in the lens system  210  at the first lens element  201  for controlling the brightness of the camera  200 . Note that the power order, shape, or other optical characteristics of the refractive lens elements may be different in some embodiments, and some embodiments may include more or fewer refractive lens elements. 
     In some embodiments, the camera  200  includes two right-angle prisms  241  and  242  to change the direction of the light passing through the camera  200 . In some embodiments, one or both of the prisms may be shifted or tilted relative to the position of the lens system  210  to provide autofocus and/or OIS functionality for the camera  200 . In some embodiments, the aperture stop  230  is integrated in the lens system  210  to control brightness in the camera  200 . Integrating the stop  230  in the lens system  210  enables the lens system  210  to be isolated from and moved independently with relation to the prisms  241  and  242 . In some embodiments, the aperture stop  230  may be fixed; the diameter of the stop  230  may be chosen according to system requirements. However, in some embodiments, the aperture stop may be adjustable. 
     In some embodiments, the camera  200  includes an IR filter  250 , for example located between light folding element  242  and photosensor  220 , to reduce or eliminate interference of environmental noises on the sensor  220 . 
     Camera  200  Z-height is sensitive to barrel  212  diameter. In some embodiments, to provide a desired Z-height for a particular camera  200  application, the structure of the barrel  212  may be modified. For example, in various embodiments of a camera  200 , the barrel  212  may be truncated, may be tapered, may be single-sided, and/or may have a reverse assembly structure. 
       FIG. 3  is a diagram illustrating a lens system that includes four refractive lens elements, according to some embodiments. A camera  300  may include a photosensor  320 , two light folding elements (e.g., prisms  341  and  342 ), and an independent lens system  310  located between the two prisms  341  and  342  that includes an aperture stop  330  and lens elements with refractive power mounted in a lens barrel. The prisms provide a “folded” optical axis for the camera, for example to reduce the Z-height of the camera. The lens system  310  includes an aperture stop  330  to control system brightness while maintaining an integrated lens system that is independent of the two prisms  341  and  342 . The camera  300  may, but does not necessarily, include an infrared (IR) filter  350 , for example located between the second prism  342  and the photosensor  320 . 
     The example lens system  310  shown in  FIG. 3  includes a lens stack consisting of four refractive elements  301 - 304  that provide a low F-number (&lt;=F/2.4), 3× optical zoom, and high resolution imaging. Lenses  301  and  302  both have positive refractive power for light converging while splitting the spherical aberration contributions of each lens  301  and  302 . Lens  303  has negative refractive power, and an aspheric shape to correct chromatic aberration and field curvature. Lens  304  is a meniscus lens to correct field curvature and enable low F-number operation of the camera  300 . In some embodiments, lens  304  may have low positive refractive power. 
     In some embodiments, the lens system  310  may be shifted along AX 2 independently of the two prisms  341  and  342  to allow refocusing of the lens system  310  between Infinity conjugate and Macro conjugate. In some embodiments, the lens system  310  may be shifted on one or more axes orthogonal to AX 2 to provide OIS functionality for the camera  300 . In various embodiments, lens elements  301 ,  302 ,  303 , and/or  304  may be round/circular or rectangular, or some other shape. Note that in various embodiments, a lens system  310  may include more or fewer refractive lens elements, and the lens elements may be configured or arranged differently. 
     In some embodiments, one or both of the prisms  341  and  342  may be shifted independently of the lens system  310  along one or more axes by a mechanical actuator mechanism to facilitate autofocus functionality for the lens system  310  between Infinity conjugate and Macro conjugate. In some embodiments, one or both of the prisms  341  and  342  may be translated with respect to the second axis (AX 2) independently of the lens system  310  and/or tilted with respect to the second axis (AX 2) independently of the lens system  342  by a mechanical actuator mechanism, for example to provide OIS functionality for the camera  300  or to shift the image formed at an image plane  321  at the photosensor  320 . 
       FIG. 4A  is a graph illustrating the modulation transfer function (MTF) for a lens system as illustrated in  FIG. 3  at infinity conjugate.  FIG. 4B  shows longitudinal spherical aberration, astigmatic field curves, and distortion for a lens system as illustrated in  FIG. 3  at infinity conjugate. 
       FIG. 5A  is a graph illustrating the modulation transfer function (MTF) for a lens system as illustrated in  FIG. 3  at macro conjugate.  FIG. 5B  shows longitudinal spherical aberration, astigmatic field curves, and distortion for a lens system as illustrated in  FIG. 3  at macro conjugate. 
       FIG. 6  is a cross-sectional illustration of a folded camera with five refractive lens elements in the lens system, according to some embodiments.  FIG. 6  shows an example camera  600  including two prisms  641  and  642  that “fold” the optical axis of the camera  600  and an example embodiment of a lens system  610  with five refractive lens elements  601 - 605  located between the prisms  641  and  642 . The lens elements  601 - 605  are mounted in a lens barrel  612 , with an aperture stop  630  located at or in front of the first (object side) lens element  601 . While embodiments are generally described as using prisms to fold the optical axis, other methods may be used to fold the optical axis, including but not limited to mirrors. The first prism  641  folds the optical axis from a first axis (AX 1) that is parallel to the incoming light direction to a second axis (AX 2) that is orthogonal to the incoming light direction. The second prism  642  folds the optical axis from the second axis (AX 2) that is orthogonal to the incoming light direction to a third axis (AX 3) that is parallel to the incoming light direction. 
     The camera  600  also includes a photosensor  620 , and may also include an optional infrared (IR) filter. A camera  600  including an embodiment of the lens system  610  as illustrated in  FIG. 6  may, for example, be implemented in portable electronic devices such as mobile phones and tablets. Embodiments of the lens system  610  may provide a low F-number (&lt;=2.4), 3× optical zoom, and high resolution imaging. 
     In some embodiments, the camera  600  may include an actuator  660  component or components configured to move the lens system  610  on (parallel to) the second axis (AX 2) relative to and independently of the prisms  641  and  642  to provide autofocus functionality for the camera  600 . In some embodiments, the actuator  660  component(s) may instead or also be configured to move the lens system  610  on one or more axes orthogonal to the second axis (AX 2) relative to and independently of the prisms  641  and  642  to provide optical image stabilization (OIS) functionality for the camera  600 . Various types of mechanical, magnetic, or other actuator technology may be used in various embodiments. In some embodiments, one or both of the prisms  641  and  642  may be translated with respect to the second axis (AX 2) independently of the lens system  610  and/or tilted with respect to the second axis (AX 2) independently of the lens system  610 , for example to provide OIS functionality for the camera  600  or to shift the image formed at an image plane  621  at the photosensor  620 . 
     As shown in the example of  FIG. 6 , embodiments of the lens system  610  may include five lens elements  601 - 605  with refractive power. Note, however, that some embodiments may include more or fewer refractive lens elements. Some embodiments of the lens system  610  may provide a 35 mm equivalent focal length in the range of 80-600 mm and less than 6.5 mm of Z-height to fit in a wide variety of portable electronics devices. With proper arrangement of materials and lens powers, embodiments of the lens system  610  are capable of capturing high brightness photographs or video frames with near diffraction-limited image quality. 
     As illustrated in the example camera  600  of  FIG. 6 , the lens system  610  may include five lens elements  601 - 605  with refractive power, in order from the object side to the image side of the camera  600 : a first lens element  601  with positive refractive power; a second lens element  602  with positive refractive power; a third lens element  603  with negative refractive power and an aspheric shape to correct chromatic aberration and field curvature; a fourth aspheric lens element  604  configured as an air-space doublet with lens element  603  that assists in the aberration correction provided by lens element  603 ; and a fifth lens element  605  with a meniscus shape to correct field curvature and provide a low F-number. At least one of the refractive lens elements may be formed of lightweight polymer or plastic material. At least two of the refractive lens elements may be formed of materials with different Abbe numbers. An aperture stop  630  may be located in the lens system  610  at the first lens element  601  for controlling the brightness of the camera  600 . Note that the power order, shape, or other optical characteristics of the refractive lens elements may be different in some embodiments, and some embodiments may include more or fewer refractive lens elements. 
     In some embodiments, the camera  600  includes two right-angle prisms  641  and  642  to change the direction of the light passing through the camera  600 . In some embodiments, one or both of the prisms may be shifted or tilted relative to the position of the lens system  610  to provide autofocus and/or OIS functionality for the camera  600 . In some embodiments, the aperture stop  630  is integrated in the lens system  610  to control brightness in the camera  600 . Integrating the stop  630  in the lens system  610  enables the lens system  610  to be isolated from and moved independently with relation to the prisms  641  and  642 . In some embodiments, the aperture stop  630  may be fixed; the diameter of the stop  630  may be chosen according to system requirements. However, in some embodiments, the aperture stop may be adjustable. 
     In some embodiments, the camera  600  includes an IR filter  650 , for example located between light folding element  642  and photosensor  620 , to reduce or eliminate interference of environmental noises on the sensor  620 . 
     Camera  600  Z-height is sensitive to barrel  612  diameter. In some embodiments, to provide a desired Z-height for a particular camera  600  application, the structure of the barrel  612  may be modified. For example, in various embodiments of a camera  600 , the barrel  612  may be truncated, may be tapered, may be single-sided, and/or may have a reverse assembly structure. 
       FIG. 7  is a diagram illustrating a lens system that includes five refractive lens elements in the lens system, according to some embodiments. A camera  700  may include a photosensor  720 , two light folding elements (e.g., prisms  741  and  742 ), and an independent lens system  710  located between the two prisms  741  and  742  that includes an aperture stop  730  and lens elements with refractive power mounted in a lens barrel. The prisms provide a “folded” optical axis for the camera, for example to reduce the Z-height of the camera. The lens system  710  includes an aperture stop  730  to control system brightness while maintaining an integrated lens system that is independent of the two prisms  741  and  742 . The camera  700  may, but does not necessarily, include an infrared (IR) filter  750 , for example located between the second prism  742  and the photosensor  720 . 
     The example lens system  710  shown in  FIG. 7  includes a lens stack consisting of five refractive elements  701 - 705  that provide a low F-number (&lt;=F/2.4), 3× optical zoom, and high resolution imaging. Lenses  701  and  702  both have positive refractive power for light converging while splitting the spherical aberration contributions of each lens  701  and  702 . Lens  703  has negative refractive power, and an aspheric shape to correct chromatic aberration and field curvature. Lens  704  works as an air space doublet with lens  703  to provide aberration correction. Lens  705  is a meniscus lens to correct field curvature and enable low F-number operation of the camera  700 . In some embodiments, lens  705  may have low positive refractive power. 
     In some embodiments, the lens system  710  may be shifted along AX 2 independently of the two prisms  741  and  742  to allow refocusing of the lens system  710  between Infinity conjugate and Macro conjugate. In some embodiments, the lens system  710  may be shifted on one or more axes orthogonal to AX 2 to provide OIS functionality for the camera  700 . In various embodiments, lens elements  701 ,  702 ,  703 ,  704 , and/or  705  may be round/circular or rectangular, or some other shape. Note that in various embodiments, a lens system  710  may include more or fewer refractive lens elements, and the lens elements may be configured or arranged differently. 
     In some embodiments, one or both of the prisms  741  and  742  may be shifted independently of the lens system  710  along one or more axes by a mechanical actuator mechanism to facilitate autofocus functionality for the lens system  710 . In some embodiments, one or both of the prisms  741  and  742  may be translated with respect to the second axis (AX 2) independently of the lens system  710  and/or tilted with respect to the second axis (AX 2) independently of the lens system  742  by a mechanical actuator mechanism, for example to provide OIS functionality for the camera  700  or to shift the image formed at an image plane  721  at the photosensor  720 . 
       FIG. 8A  is a graph illustrating the modulation transfer function (MTF) for a lens system as illustrated in  FIG. 7  at infinity conjugate.  FIG. 8B  shows longitudinal spherical aberration, astigmatic field curves, and distortion for a lens system as illustrated in  FIG. 7  at infinity conjugate. 
       FIG. 9A  is a graph illustrating the modulation transfer function (MTF) for a lens system as illustrated in  FIG. 7  at macro conjugate.  FIG. 9B  shows longitudinal spherical aberration, astigmatic field curves, and distortion for a lens system as illustrated in  FIG. 7  at macro conjugate. 
       FIG. 10  is a diagram illustrating a lens system that includes four refractive lens elements, according to some embodiments. A camera  1000  may include a photosensor  1020 , two light folding elements (e.g., prisms  1041  and  1042 ), and an independent lens system  1010  located between the two prisms  1041  and  1042  that includes an aperture stop  1030  and lens elements with refractive power mounted in a lens barrel. The prisms provide a “folded” optical axis for the camera, for example to reduce the Z-height of the camera. The lens system  1010  includes an aperture stop  1030  to control system brightness while maintaining an integrated lens system that is independent of the two prisms  1041  and  1042 . The camera  1000  may, but does not necessarily, include an infrared (IR) filter  1050 , for example located between the second prism  1042  and the photosensor  1020 . 
     The example lens system  1010  shown in  FIG. 10  includes a lens stack consisting of four refractive elements  1001 - 1004  that provide a low F-number (&lt;=F/2.4), 3× optical zoom, and high resolution imaging. Lens  1001  has positive refractive power for light converging while being aspheric to control spherical aberration. Lens  1002  has negative refractive power and has an Abbe number that is less than 30. Lens  1003  is a meniscus lens, and has a concave object-side surface in the paraxial region and a convex image-side surface in the paraxial region. Lens  1004  is a meniscus lens to correct field curvature and enable low F-number operation of the camera  1000 . 
     In some embodiments, the lens system  1010  may be shifted along the second axis (AX 2) independently of the two prisms  1041  and  1042  to allow refocusing of the lens system  1010  between Infinity conjugate and Macro conjugate. In some embodiments, the lens system  1010  may be shifted on one or more axes orthogonal to AX 2 to provide OIS functionality for the camera  1000 . In various embodiments, lens elements  1001 ,  1002 ,  1003 , and/or  1004  may be round/circular or rectangular, or some other shape. Note that in various embodiments, a lens system  1010  may include more or fewer refractive lens elements, and the lens elements may be configured or arranged differently. 
     In some embodiments, one or both of the prisms  1041  and  1042  may be shifted independently of the lens system  1010  along one or more axes by a mechanical actuator mechanism to facilitate autofocus functionality for the lens system  1010 . In some embodiments, one or both of the prisms  1041  and  1042  may be translated with respect to the second axis (AX 2) independently of the lens system  1010  and/or tilted with respect to the second axis (AX 2) independently of the lens system  1042  by a mechanical actuator mechanism, for example to provide OIS functionality for the camera  1000  or to shift the image formed at an image plane  1021  at the photosensor  1020 . 
       FIG. 11A  is a graph illustrating the modulation transfer function (MTF) for a lens system as illustrated in  FIG. 10 .  FIG. 11B  shows longitudinal spherical aberration, astigmatic field curves, and distortion for a lens system as illustrated in  FIG. 10 . 
     Example Flowchart 
       FIG. 12  is a flowchart of a method for capturing images using embodiments of a camera as illustrated in  FIGS. 1 through 11B , according to some embodiments. As indicated at  1900 , light from an object field in front of the camera is received at a first light folding element such as a prism on a first axis. As indicated at  1910 , the light is redirected by the first prism to a second axis. As indicated at  1920 , the light is received through an aperture at a first lens of a lens system on the second axis. As indicated at  1930 , the light is refracted by one or more lens elements of the lens system on the second axis to a second light folding element such as a prism. As indicated at  1940 , the light is redirected by the second light folding element to a third axis. As indicated at  1950 , the light forms an image at an image plane at or near the surface of a sensor module on the third axis. As indicated at  1960 , the image is captured by the photosensor. The lens system is independent of the first and second prisms. The camera may include an actuator component configured to move the lens system on one or more axes independently of the prisms to provide autofocus and/or OIS functionality for the camera. 
     While not shown in  FIG. 12 , in some embodiments, the light may pass through an infrared filter that may for example be located between the second light folding element and the photosensor. In some embodiments, the aperture stop may be fixed; the diameter of the stop may be chosen according to system requirements. However, in some embodiments, the aperture stop may be adjustable. In some embodiments, one or both of the prisms are fixed. However, in some embodiments, one or both of the prisms may be shifted or tilted with respect to the second axis and independently of the lens system. 
     In some embodiments, the components of the lens system referred to in  FIG. 12  may be configured as illustrated in any of  FIG. 2, 3, 6, 7 or 10 . However, note that variations on the examples given in the Figures are possible while achieving similar optical results. 
     Example Computing Device 
       FIG. 13  illustrates an example computing device, referred to as computer system  2000 , that may include or host embodiments of a camera with a lens system as illustrated in  FIGS. 1 through 12 . In addition, computer system  2000  may implement methods for controlling operations of the camera and/or for performing image processing of images captured with the camera. In different embodiments, computer system  2000  may be any of various types of devices, including, but not limited to, a personal computer system, desktop computer, laptop, notebook, tablet or pad device, slate, or netbook computer, mainframe computer system, handheld computer, workstation, network computer, a camera, a set top box, a mobile device, a wireless phone, a smartphone, a consumer device, video game console, handheld video game device, application server, storage device, a television, a video recording device, a peripheral device such as a switch, modem, router, or in general any type of computing or electronic device. 
     In the illustrated embodiment, computer system  2000  includes one or more processors  2010  coupled to a system memory  2020  via an input/output (I/O) interface  2030 . Computer system  2000  further includes a network interface  2040  coupled to I/O interface  2030 , and one or more input/output devices  2050 , such as cursor control device  2060 , keyboard  2070 , and display(s)  2080 . Computer system  2000  may also include one or more cameras  2090 , for example one or more cameras as described above with respect to  FIGS. 1 through 12 , which may also be coupled to I/O interface  2030 , or one or more cameras as described above with respect to  FIGS. 1 through 12  along with one or more other cameras such as conventional wide-field cameras. 
     In various embodiments, computer system  2000  may be a uniprocessor system including one processor  2010 , or a multiprocessor system including several processors  2010  (e.g., two, four, eight, or another suitable number). Processors  2010  may be any suitable processor capable of executing instructions. For example, in various embodiments processors  2010  may be general-purpose or embedded processors implementing any of a variety of instruction set architectures (ISAs), such as the x86, PowerPC, SPARC, or MIPS ISAs, or any other suitable ISA. In multiprocessor systems, each of processors  2010  may commonly, but not necessarily, implement the same ISA. 
     System memory  2020  may be configured to store program instructions  2022  and/or data  2032  accessible by processor  2010 . In various embodiments, system memory  2020  may be implemented using any suitable memory technology, such as static random access memory (SRAM), synchronous dynamic RAM (SDRAM), nonvolatile/Flash-type memory, or any other type of memory. In the illustrated embodiment, program instructions  2022  may be configured to implement various interfaces, methods and/or data for controlling operations of camera  2090  and for capturing and processing images with integrated camera  2090  or other methods or data, for example interfaces and methods for capturing, displaying, processing, and storing images captured with camera  2090 . In some embodiments, program instructions and/or data may be received, sent or stored upon different types of computer-accessible media or on similar media separate from system memory  2020  or computer system  2000 . 
     In one embodiment, I/O interface  2030  may be configured to coordinate I/O traffic between processor  2010 , system memory  2020 , and any peripheral devices in the device, including network interface  2040  or other peripheral interfaces, such as input/output devices  2050 . In some embodiments, I/O interface  2030  may perform any necessary protocol, timing or other data transformations to convert data signals from one component (e.g., system memory  2020 ) into a format suitable for use by another component (e.g., processor  2010 ). In some embodiments, I/O interface  2030  may include support for devices attached through various types of peripheral buses, such as a variant of the Peripheral Component Interconnect (PCI) bus standard or the Universal Serial Bus (USB) standard, for example. In some embodiments, the function of I/O interface  2030  may be split into two or more separate components, such as a north bridge and a south bridge, for example. Also, in some embodiments some or all of the functionality of I/O interface  2030 , such as an interface to system memory  2020 , may be incorporated directly into processor  2010 . 
     Network interface  2040  may be configured to allow data to be exchanged between computer system  2000  and other devices attached to a network  2085  (e.g., carrier or agent devices) or between nodes of computer system  2000 . Network  2085  may in various embodiments include one or more networks including but not limited to Local Area Networks (LANs) (e.g., an Ethernet or corporate network), Wide Area Networks (WANs) (e.g., the Internet), wireless data networks, some other electronic data network, or some combination thereof. In various embodiments, network interface  2040  may support communication via wired or wireless general data networks, such as any suitable type of Ethernet network, for example; via telecommunications/telephony networks such as analog voice networks or digital fiber communications networks; via storage area networks such as Fibre Channel SANs, or via any other suitable type of network and/or protocol. 
     Input/output devices  2050  may, in some embodiments, include one or more display terminals, keyboards, keypads, touchpads, scanning devices, voice or optical recognition devices, or any other devices suitable for entering or accessing data by computer system  2000 . Multiple input/output devices  2050  may be present in computer system  2000  or may be distributed on various nodes of computer system  2000 . In some embodiments, similar input/output devices may be separate from computer system  2000  and may interact with one or more nodes of computer system  2000  through a wired or wireless connection, such as over network interface  2040 . 
     As shown in  FIG. 16 , memory  2020  may include program instructions  2022 , which may be processor-executable to implement any element or action to support integrated camera  2090 , including but not limited to image processing software and interface software for controlling camera  2090 . In some embodiments, images captured by camera  2090  may be stored to memory  2020 . In addition, metadata for images captured by camera  2090  may be stored to memory  2020 . 
     Those skilled in the art will appreciate that computer system  2000  is merely illustrative and is not intended to limit the scope of embodiments. In particular, the computer system and devices may include any combination of hardware or software that can perform the indicated functions, including computers, network devices, Internet appliances, PDAs, wireless phones, pagers, video or still cameras, etc. Computer system  2000  may also be connected to other devices that are not illustrated, or instead may operate as a stand-alone system. In addition, the functionality provided by the illustrated components may in some embodiments be combined in fewer components or distributed in additional components. Similarly, in some embodiments, the functionality of some of the illustrated components may not be provided and/or other additional functionality may be available. 
     Those skilled in the art will also appreciate that, while various items are illustrated as being stored in memory or on storage while being used, these items or portions of them may be transferred between memory and other storage devices for purposes of memory management and data integrity. Alternatively, in other embodiments some or all of the software components may execute in memory on another device and communicate with the illustrated computer system  2000  via inter-computer communication. Some or all of the system components or data structures may also be stored (e.g., as instructions or structured data) on a computer-accessible medium or a portable article to be read by an appropriate drive, various examples of which are described above. In some embodiments, instructions stored on a computer-accessible medium separate from computer system  2000  may be transmitted to computer system  2000  via transmission media or signals such as electrical, electromagnetic, or digital signals, conveyed via a communication medium such as a network and/or a wireless link. Various embodiments may further include receiving, sending or storing instructions and/or data implemented in accordance with the foregoing description upon a computer-accessible medium. Generally speaking, a computer-accessible medium may include a non-transitory, computer-readable storage medium or memory medium such as magnetic or optical media, e.g., disk or DVD/CD-ROM, volatile or non-volatile media such as RAM (e.g. SDRAM, DDR, RDRAM, SRAM, etc.), ROM, etc. In some embodiments, a computer-accessible medium may include transmission media or signals such as electrical, electromagnetic, or digital signals, conveyed via a communication medium such as network and/or a wireless link. 
     The methods described herein may be implemented in software, hardware, or a combination thereof, in different embodiments. In addition, the order of the blocks of the methods may be changed, and various elements may be added, reordered, combined, omitted, modified, etc. Various modifications and changes may be made as would be obvious to a person skilled in the art having the benefit of this disclosure. The various embodiments described herein are meant to be illustrative and not limiting. Many variations, modifications, additions, and improvements are possible. Accordingly, plural instances may be provided for components described herein as a single instance. Boundaries between various components, operations and data stores are somewhat arbitrary, and particular operations are illustrated in the context of specific illustrative configurations. Other allocations of functionality are envisioned and may fall within the scope of claims that follow. Finally, structures and functionality presented as discrete components in the example configurations may be implemented as a combined structure or component. These and other variations, modifications, additions, and improvements may fall within the scope of embodiments as defined in the claims that follow.

Metadata:
Filing Date: 20190131
Publication Date: 20210713
Grant Date: 20210713
Priority Date: 20180207
Inventors: YAO, YUHONG
SCEPANOVIC, MIODRAG
Assignee: APPLE INC
CPC Classifications: [{"code": "H04N23/687", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B27/646", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B13/0065", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B7/102", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B13/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B7/09", "inventive": true, "first": false, "tree": "[]"}, {"code": "G03B2205/0007", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B13/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B9/34", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B13/0065", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B13/004", "inventive": true, "first": false, "tree": "[]"}, {"code": "G03B13/36", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B7/102", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B9/60", "inventive": true, "first": false, "tree": "[]"}, {"code": "G03B5/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B27/646", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B13/0045", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B7/1805", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B17/08", "inventive": true, "first": true, "tree": "[]"}, {"code": "G03B13/36", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B7/102", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B27/646", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B9/60", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B13/0045", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B13/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04N5/23287", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B13/0065", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B17/08", "inventive": true, "first": true, "tree": "[]"}, {"code": "G03B5/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "G03B2205/0007", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B7/1805", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B9/34", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B7/09", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B13/004", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B13/004", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 67476602