Switchable viewing angle display with a compact directional backlight and striped diffuser

Area of Science:

• Optoelectronics
• Display Technology

Background:

• Conventional backlights lack adjustable viewing angles, leading to energy inefficiency.
• Eco-displays require power-saving features for enhanced user experience.

Purpose of the Study:

• To develop a compact backlight module with an adjustable viewing angle for eco-displays.
• To improve optical efficiency and reduce power consumption in display technology.

Main Methods:

• A compact high-directionality backlight module was designed using micro-prisms on a light guide plate.
• A striped diffuser was integrated to enable switching between narrow and wide viewing angles.
• Optical performance, including viewing angle and luminance uniformity, was evaluated.

Main Results:

• Achieved adjustable viewing cones of ± 10° (narrow) and ± 55° (wide) with high luminance uniformity (88% / 85%).
• Demonstrated increased optical efficiencies by factors of 1.47 (narrow) and 1.38 (wide) compared to conventional backlights.
• Showcased a 95% power consumption reduction in private narrow viewing mode to maintain equivalent luminance.

Conclusions:

• The proposed backlight module effectively provides adjustable viewing angles for eco-displays.
• The design significantly enhances optical efficiency and offers substantial power savings, particularly for private viewing.
• This technology presents a promising solution for energy-efficient and versatile display applications.