US 11,948,520 B2
Variable refresh rate control using PWM-aligned frame periods
Sang Young Youn, Cupertino, CA (US); Sun-il Chang, San Jose, CA (US); Wonjae Choi, San Jose, CA (US); and Sangmoo Choi, Palo Alto, CA (US)
Assigned to GOOGLE LLC, Mountain View, CA (US)
Appl. No. 17/786,961
Filed by GOOGLE LLC, Mountain View, CA (US)
PCT Filed Mar. 31, 2020, PCT No. PCT/US2020/025980
§ 371(c)(1), (2) Date Jun. 17, 2022,
PCT Pub. No. WO2021/201844, PCT Pub. Date Oct. 7, 2021.
Prior Publication US 2023/0030201 A1, Feb. 2, 2023
Int. Cl. G09G 3/34 (2006.01)
CPC G09G 3/3406 (2013.01) [G09G 2320/0252 (2013.01); G09G 2320/064 (2013.01); G09G 2340/0435 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method comprising:
controlling a brightness of frames displayed at a display panel via pulse width modulation (PWM) of a brightness control signal provided to the display panel;
selecting, for display of frames at the display panel, a target frame rate that is between a minimum frame rate and maximum frame rate and which is an integer divisor of a PWM frequency of the brightness control signal so that a corresponding frame period for the target frame rate is an integer multiple of a PWM period of the brightness control signal; and
providing frames for display based on the target frame rate such that a frame period of each frame is aligned with a corresponding PWM cycle of the brightness control signal.