US 12,075,025 B2
Camera testing device and method for testing focusing characteristic of camera
Hun Kim, Icheon-si (KR); Jong Heon Kim, Icheon-si (KR); and Woo Young Choi, Icheon-si (KR)
Assigned to SK HYNIX INC., Icheon-si (KR)
Filed by SK hynix Inc., Icheon-si (KR)
Filed on Sep. 8, 2022, as Appl. No. 17/940,887.
Claims priority of application No. 10-2021-0133204 (KR), filed on Oct. 7, 2021.
Prior Publication US 2023/0116098 A1, Apr. 13, 2023
Int. Cl. H04N 17/00 (2006.01); G06T 7/62 (2017.01); H04N 23/67 (2023.01)
CPC H04N 17/002 (2013.01) [G06T 7/62 (2017.01); H04N 23/672 (2023.01)] 20 Claims
OG exemplary drawing
 
1. A method for testing a focusing characteristic of a camera, the method comprising:
setting a camera to align the camera and a first chart structured to provide a first scene for testing such that the camera is focused on the first chart disposed at a first distance from the camera;
measuring a blur in an image of a second chart captured at a second distance from the camera, the second chart being structured to provide a second scene for testing; and
evaluating a phase difference range (PDR) of the camera by comparing the measured blur with a blur calculated through a circle of confusion (CoC) model,
wherein the PDR indicates a range from a minimum phase difference to a maximum phase difference.