US 12,313,453 B2
Method for measuring intensity of ambient light at electronic device, electronic device, and chip
Enqi Fu, Guangdong (CN); Songjin Zhong, Guangdong (CN); and Leigang Cheng, Guangdong (CN)
Assigned to SHENZHEN GOODIX TECHNOLOGY CO., LTD., Shenzhen (CN)
Filed by Shenzhen Goodix Technology Co., Ltd., Guangdong (CN)
Filed on Nov. 9, 2022, as Appl. No. 18/054,138.
Claims priority of application No. 202210153099.3 (CN), filed on Feb. 18, 2022.
Prior Publication US 2023/0266162 A1, Aug. 24, 2023
Int. Cl. G01J 1/42 (2006.01); G09G 3/3208 (2016.01)
CPC G01J 1/4204 (2013.01) [G09G 3/3208 (2013.01); G09G 2320/0626 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A method for measuring an intensity of ambient light at an electronic device, the electronic device comprising a screen configured to be dimmed at a dimming frequency, the method comprising:
collecting mixed light including the ambient light and screen leakage light;
obtaining a direct current (DC) mean value of the mixed light, including:
converting the mixed light from a time domain into a frequency domain through a fast Fourier transform; and
obtaining, from a waveform of the mixed light in the frequency domain, a frequency point amplitude corresponding to the mixed light at 0 Hz and a frequency point amplitude corresponding to the mixed light at the dimming frequency; wherein the frequency point amplitude corresponding to the mixed light at 0 Hz is the DC mean value of the mixed light, and the frequency point amplitude corresponding to the mixed light at the dimming frequency is equal to a frequency point amplitude corresponding to the screen leakage light at the dimming frequency;
obtaining a DC mean value of the screen leakage light according to the frequency point amplitude corresponding to the mixed light at the dimming frequency and at least one calibration parameter, wherein the DC mean value of the screen leakage light is represented by a frequency point amplitude corresponding to the screen leakage light at 0 Hz, and the DC mean value of the screen leakage light is linearly related to the frequency point amplitude corresponding to the screen leakage light at the dimming frequency; and
determining a DC mean value of the ambient light by subtracting the DC mean value of the screen leakage light from the DC mean value of the mixed light; wherein
the DC mean value of the ambient light is indicative of the intensity of the ambient light.