US 2023/0422369 A1Published application

Automatic compensation method based on temperature characteristics of rgb leds

AssigneeSi En Technology (Xiamen) Limited

InventorsYunFeng LI, JunHao Li, Hui ZHANG, MingChi HUANG, KunFu LU

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Abstract

An automatic compensation method based on temperature characteristics of RGB LEDs by first obtaining current temperatures of the RGB LEDs, and then adjusting a corresponding PWM duty cycle of each LED according to the current temperature of each LED to change drive currents of the RGB LEDs, thereby achieving compensation for the RGB LEDs. By determining a temperature adjustment coefficient of each LED based on the current temperature, temperature adjustment ratios, and an adjustment step size of the LED, and finally adjusting the PWM value according to the temperature adjustment coefficient to drive the LED, color shift is reduced. When performing PWM duty cycle adjustment, adjustment formulae are used, which only require obtaining the current temperature, the temperature adjustment ratios, and the adjustment step size of each LED, and then calculating according to the formula, therefore not requiring extensive data storage or data lookup and thus resulting in lesser computation.

Claims4

Dependent claims

An automatic compensation method based on temperature characteristics of RGB LEDs, comprising the following steps:

obtaining current temperatures of a red LED, a green LED, and a blue LED of the RGB LEDs respectively;
and
adjusting a corresponding pulse width modulation (PWM) duty cycle of each LED according to the current temperature of each LED so as to change drive currents of the red LED, the green LED, and the blue LED, thereby achieving compensation for the RGB LEDs;
wherein,
a PWM duty cycle of the red LED is adjusted according to the following formula:
PWMOUT_R=PWMIN_R×TCR=PWMIN_R×[1+(T_ADC_R−TADC@25_R)/KR×NR %];
a PWM duty cycle of the green LED is adjusted according to the following formula:
PWMOUT_G=PWMIN_G×TCG=PWMIN_G×[1+(T_ADC_G−TADC@25_G)/KG×NG %];
a PWM duty cycle of the blue LED is adjusted according to the following formula:
PWMOUT_B=PWMIN_B×TCB=PWMIN_B×[1+(TADC_B−TADC@25_B)/KB×NB%];
wherein PWMOUT_R, PWMOUT_G, and PWMOUT_B represent adjusted PWM values for the red LED, the green LED, and the blue LED respectively;
PWMIN_R, PWMIN_G, and PWMIN_B represent original PWM values for the red LED, the green LED, and the blue LED respectively before adjustment;
TCR, TCG, and TCB represent temperature adjustment coefficients for the red LED, the green LED, and the blue LED respectively;
T_ADC_R, TADC_G, and TADC_B represent the current temperatures of the red LED, the green LED, and the blue LED respectively;
TADC@25_R, TADC@25_G, and TADC@25_B represent temperatures of the red LED, the green LED, and the blue LED respectively at room temperature;
KR, KG, and KB represent temperature adjustment step sizes for the red LED, the green LED, and the blue LED respectively, and values of KR, KG, and KB are identical;
NR%, NG%, and NB% represent temperature adjustment percentages for the red LED, green LED, and the blue LED respectively.

14 more elements

Dependencies are inferred from the claim text.