Characterization of the stroboscopic effect for OLED displays using the PWM dimming method

Area of Science:

• Visual Perception
• Display Technology
• Human-Computer Interaction

Background:

• Organic light-emitting diode (OLED) displays are prevalent in smartphones.
• Pulse-width modulation (PWM) dimming is used, potentially causing flicker.
• The stroboscopic visibility measure (SVM), developed for lighting, is used to assess OLED flicker.

Purpose of the Study:

• To investigate the impact of dimming frequency and display luminance on the stroboscopic effect in OLED smartphone displays.
• To determine the visibility thresholds of the stroboscopic effect under varying conditions.
• To evaluate the applicability of the SVM for OLED displays.

Main Methods:

• An oscillating arm was presented in front of an OLED smartphone display.
• Dimming frequency and display luminance were systematically varied.
• Perceptual visibility of the stroboscopic effect was recorded.

Main Results:

• The stroboscopic effect was visible at 480 Hz and 960 Hz below 40 cd/m² luminance.
• At 1440 Hz and 5 cd/m², a 50% duty cycle showed visible flicker.
• No stroboscopic effect was observed at 1920 Hz or 2160 Hz.

Conclusions:

• The stroboscopic effect on OLED displays is dependent on dimming frequency and luminance.
• The SVM can be applied to OLEDs, but a conservative threshold (SVM 1.5-2) is recommended.
• Further research may refine SVM application for display technologies.