Working principles and comparison of advantages and disadvantages of LCD and OLED part 5

2.7. OLED is prone to screen burn-in.

The backlight of the LCD screen is one piece, and all the pixels will age together. Each pixel of the OLED screen emits light independently, which means that different areas of the screen will age at different rates depending on the degree of use.

For example, if area A displays blue for a long time, the blue pixels will decay faster. The next time you display a solid color, the blue in that area will be slightly darker, resulting in an afterimage, as if the image has been burned onto the screen. This phenomenon is called screen burn. This does not mean that the screen is physically burned, but that the color of the screen is caused by uneven pixel aging.

2.8. Both LCD screen and OLED can hurt your eyes, but they are different.

The brightness of the mobile phone screen needs to be controllable, otherwise it cannot match the ambient light intensity. Currently, there are two main ways to control the brightness: PWM and DC adjustment.

DC dimming is very simple. It directly controls the voltage to change the brightness of the lamp. The higher the voltage, the brighter the brightness. DC dimming does not cause stroboscopic eye damage because the light source is on throughout the entire process.

PWM dimming adjusts the duty cycle to adjust the brightness of the control light. The greater the duty cycle, the brighter the brightness. Its dimming controls the switching time of the light, which will produce stroboscopic effects, so it has the disadvantage of hurting the eyes. The higher the frequency, the less obvious the stroboscopic phenomenon.