System and method for remote measurement of optical focus
First Claim
1. A measurement system for remote measurement of an optical focus of a distant optical imaging system, the distant optical imaging system comprising a lens and a sensor surface, wherein the measurement system comprises:
- a light projection device (P) for projecting a luminous pattern of light such that the pattern is in focus at a known focal plane (FPL1) in front of the lens of the distant optical imaging system;
a camera (CAM) having an optical axis (AXCAM) which, between the light projection device (P) and the known focal plane (FPL1), at least partly coincides with the optical axis (AXP) of the light projection device (P), for recording an image of the reflection of the luminous pattern on the sensor surface of the distant optical imaging system; and
an image processing unit (IP) for determining a sharpness of the recorded luminous pattern reflected on the sensor surface for measuring a focal distance of the distant optical imaging system.
1 Assignment
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Accused Products
Abstract
A system and method that measures an optical focus of a distant optical imaging system (EYE), in particular the ocular accommodation of a distant human subject. A luminous pattern of light (P1, A1) is projected by a projector (P) in focus (A2) at a known focal plane (FPL1) in front of the distant optical imaging system (EYE), and an image of the reflection of the pattern (A3) on a sensor surface of the distant optical imaging system (EYE), for instance the retina of an eye, is recorded by a camera (CAM) having an optical axis (AXCAM) coinciding at least partly with or situated close to the optical axis (AXP) of the projection device (P). The sharpness of the luminous pattern (A3) reflected from the sensor surface (retina) is determined.
18 Citations
18 Claims
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1. A measurement system for remote measurement of an optical focus of a distant optical imaging system, the distant optical imaging system comprising a lens and a sensor surface, wherein the measurement system comprises:
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a light projection device (P) for projecting a luminous pattern of light such that the pattern is in focus at a known focal plane (FPL1) in front of the lens of the distant optical imaging system; a camera (CAM) having an optical axis (AXCAM) which, between the light projection device (P) and the known focal plane (FPL1), at least partly coincides with the optical axis (AXP) of the light projection device (P), for recording an image of the reflection of the luminous pattern on the sensor surface of the distant optical imaging system; and an image processing unit (IP) for determining a sharpness of the recorded luminous pattern reflected on the sensor surface for measuring a focal distance of the distant optical imaging system. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for remotely measuring an optical focus of a distant optical imaging system, the distant optical imaging system comprising a lens and a sensor surface, the method comprising the steps of:
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projecting a luminous pattern of light in focus at a known focal plane in front of the lens of the distant optical imaging system by a light projection device; recording an image of the reflection of the luminous pattern on the sensor surface of the distant optical imaging system by a camera having an optical axis which, between the light projection device and the known focal plane, at least partly coincides with the optical axis of the projection device; and analyzing sharpness of the recorded luminous pattern reflected on the sensor surface for measuring a focal distance of the distant optical imaging system. - View Dependent Claims (13, 14, 15, 16, 17, 18)
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Specification