Folded lens system with three refractive lenses
AssigneeApple Inc.
InventorsYuhong Yao, Yoshikazu Shinohara
Life of this patent
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Abstract
Compact folded lens systems are described that may be used in small form factor cameras. Lens systems are described that may include three lens elements with refractive power, with a light folding element such as a prism, located between a first lens element on the object side of the lens system and a second lens element, that redirects the light refracted from the first lens element from a first axis onto a second axis on which the other lens elements and a photosensor are arranged. The lens systems may include an aperture stop located behind the front vertex of the lens system, for example at the first lens element, and an optional infrared filter, for example located between the last lens element and a photosensor.
Claims20
A camera, comprising:
- a photosensor configured to capture light projected onto a surface of the photosensor;
- and
- a folded lens system configured to refract light from an object field located in front of the camera to form an image of a scene at an image plane at or near the surface of the photosensor, wherein the lens system comprises three refractive lens elements arranged in a consecutive order of lens elements along a folded optical axis of the camera from an object side to an image side and a light folding element located between a first and second lens element of the three refractive lens elements and configured to redirect light from a first axis onto a second axis, wherein a third lens element of the three refractive lens elements is a last refractive lens element along the folded axis prior to the image plane;
- wherein the photosensor is configured to move relative to the folded lens system.
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;
- and
- a folded lens system configured to refract light from an object field located in front of the camera to form an image of a scene at an image plane at or near the surface of the photosensor, wherein the lens system comprises three refractive lens elements arranged in a consecutive order of lens elements along a folded optical axis of the camera from an object side to an image side and a light folding element located between a first and second lens element of the three refractive lens elements and configured to redirect light from a first axis onto a second axis, wherein a third lens element of the three refractive lens elements is a last refractive lens element along the folded axis prior to the image plane;
- wherein the photosensor is configured to move relative to the folded lens system.
A camera, comprising:
- a photosensor configured to capture light projected onto a surface of the photosensor;
- and
- a folded lens system configured to refract light from an object field located in front of the camera to form an image of a scene at an image plane at or near the surface of the photosensor, wherein the lens system comprises three refractive lens elements arranged in a consecutive order of lens elements along a folded optical axis of the camera from an object side to an image side and a light folding element located between a first and second lens element of the three refractive lens elements and configured to redirect light from a first axis onto a second axis, wherein a third lens element of the three refractive lens elements is a last refractive lens element along the folded axis prior to the image plane;
- and
- wherein the folded lens system satisfies one or more of the relationships:
- 0.5<|f/f1|<2
- 0.4<|f/f2|<2.5, or
- 0.5<|R3f/R3r|<1.5
- where f is effective focal length of the lens system, f1 is focal length of the first lens element, f2 is focal length of the second lens element, R3f is radius of curvature of the object-side surface of the third lens element, and R3r is radius of curvature of the image side surface of the third lens element.
Dependencies are inferred from the claim text.