Light-Emitting Driving Circuit Reducing Color Shift

The patent applies pulse width modulation (PWM) to drive light-emitting components using periodic pulse signals instead of continuous currents. By varying the pulse width (duty cycle) while maintaining a constant reference current, the invention achieves different luminance levels without the color shift that occurs with variable current magnitudes. The light-emitting component is switched on and off periodically, and the human eye perceives the average luminance based on the duty cycle.

The invention changes the temporal parameter (pulse width/duty cycle) instead of the current magnitude parameter to control luminance. By keeping the current magnitude constant and varying only the duration of current application within each frame cycle, the system achieves luminance control while avoiding color shift. This parameter transformation from current magnitude to time duration is the core of the solution.

The patent implements PWM control in each pixel of the active matrix, where light-emitting components are driven by periodic pulse signals rather than continuous currents. Each pixel can be independently controlled with updated pulse widths for each frame cycle, maintaining the high driving efficiency and service life benefits of active matrix while eliminating color shift through constant current magnitude.

The invention transforms the control parameter from current magnitude to pulse width while maintaining continuous independent driving capability. Each pixel receives updated pulse width instructions each frame cycle, preserving the responsiveness and efficiency of active matrix driving while avoiding color shift by keeping current magnitude constant.