US 12,302,010 B2
Stereoscopic imaging platform with continuous autofocusing mode
Patrick Terry, Goleta, CA (US)
Assigned to Alcon Inc., Fribourg (CH)
Filed by Alcon Inc., Fribourg (CH)
Filed on Mar. 26, 2024, as Appl. No. 18/617,036.
Application 18/617,036 is a continuation of application No. 17/684,851, filed on Mar. 2, 2022, granted, now 11,974,053.
Claims priority of provisional application 63/167,406, filed on Mar. 29, 2021.
Prior Publication US 2024/0236515 A1, Jul. 11, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H04N 23/959 (2023.01); A61B 90/00 (2016.01); G06T 7/593 (2017.01); H04N 13/204 (2018.01); H04N 13/296 (2018.01); H04N 23/67 (2023.01); H04N 23/695 (2023.01); H04N 13/00 (2018.01)
CPC H04N 23/959 (2023.01) [A61B 90/361 (2016.02); G06T 7/593 (2017.01); H04N 13/204 (2018.05); H04N 13/296 (2018.05); H04N 23/673 (2023.01); H04N 23/695 (2023.01); A61B 90/37 (2016.02); G06T 2207/10021 (2013.01); G06T 2207/30004 (2013.01); H04N 2013/0081 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method for imaging a target site with a stereoscopic imaging platform having a stereoscopic camera and a controller with a processor and tangible, non-transitory memory on which instructions are recorded, the method comprising:
recording a left image and a right image of the target site, via the stereoscopic camera, to generate at least one stereoscopic image of the target site, the stereoscopic camera being movable relative to the target site;
wherein a lens assembly is incorporated in the stereoscopic camera, the lens assembly having at least one lens and defining a working distance, the lens assembly having at least one focus motor adapted to move the at least one lens to selectively vary the working distance;
wherein a robotic arm is connected to the stereoscopic camera, the robotic arm being adapted to selectively move the stereoscopic camera relative to the target site;
executing a continuous autofocus mode for maintaining a focus of the at least one stereoscopic image while the robotic arm is moving the stereoscopic camera and the target site is moving along at least an axial direction;
calculating an updated focal length at a current position of the target site based in part on a change in a target depth;
obtaining the change in the target depth based on a difference between an initial target disparity at an initial target position and a current disparity value at the current position;
minimizing the difference between the current disparity value and the initial target disparity, via execution of a closed-loop control module, the closed-loop control module being a proportional-integral-derivative control module defining a proportional constant, an integral constant and a derivative constant; and
determining the change in the target depth as

OG Complex Work Unit Math
where Rc is the current disparity value, Rt is the initial target disparity, t is time, Kp is the proportional constant, Ki is the integral constant, and Kd is the derivative constant.