US 11,758,281 B2
Systems and methods of eliminating video flicker caused by LED duty cycling to maintain brightness and control power consumption
Walter A. Martin, Ballymena (GB); and Terry Neill, Lisburn (GB)
Assigned to Johnson Controls Tyco IP Holdings LLP, Milwaukee, WI (US)
Filed by Johnson Controls Tyco IP Holdings LLP, Milwaukee, WI (US)
Filed on Nov. 29, 2021, as Appl. No. 17/536,963.
Application 17/536,963 is a continuation of application No. 16/156,806, filed on Oct. 10, 2018, granted, now 11,196,940.
Prior Publication US 2022/0086327 A1, Mar. 17, 2022
Int. Cl. H04N 23/745 (2023.01); H04N 23/71 (2023.01); H04N 23/73 (2023.01)
CPC H04N 23/745 (2023.01) [H04N 23/71 (2023.01); H04N 23/73 (2023.01)] 16 Claims
OG exemplary drawing
 
1. A video camera system, comprising:
a video capture device to generate a plurality of frames, the video capture device comprising a shutter to selectively permit light to be received for generating the plurality of frames based on a shutter speed; and
one or more processors to:
determine a first luminance of a first frame of the plurality of frames and a second luminance of a second frame of the plurality of frames;
compare the first luminance of the first frame with the second luminance of the second frame to determine a highest expected luminance;
determine a target shutter speed for the shutter based on a frequency corresponding to the highest expected luminance;
cause the shutter to operate at the target shutter speed;
determine that a change in luminance between consecutive frames of the plurality of frames is greater than a threshold change in luminance;
compare the target shutter speed to a minimum shutter speed;
adjust the target shutter speed to determine an adjusted target shutter speed responsive to determining that the change in luminance is greater than the threshold change in luminance and to be equal to the minimum shutter speed responsive to the target shutter speed being less than the minimum shutter speed; and
cause the shutter to operate at the adjusted target shutter speed.