Light control using vertically aligned dichroic dye films for windshield antireflection in automotive displays

Area of Science:

• Optics and Photonics
• Materials Science

Background:

• Display panels often suffer from light leakage at various viewing angles.
• Controlling light emission direction is crucial for enhancing display performance and privacy.

Purpose of the Study:

• To develop a novel optical film for display panels to block light emission in specific directions.
• To improve viewing angle performance and reduce light leakage in displays.

Main Methods:

• Lamination of a vertically aligned dichroic dye (VA-Dye) film onto a display panel.
• Integration of a positive biaxial (+B) retarder with the VA-Dye film.
• Analysis of polarization optics and light transmission at different viewing angles.

Main Results:

• Complete elimination of upward/downward light emission was achieved in the vertical viewing angle.
• The addition of a +B retarder extended effective light blocking to diagonal viewing angles.
• The VA-Dye film demonstrated significantly lower upward transmittance across a wide viewing range compared to a reference panel.
• The VA-Dye film offers lower thickness, easier fabrication, and reduced cost.

Conclusions:

• The VA-Dye film with a +B retarder effectively controls display light emission, enhancing viewing angle performance.
• This technology presents a cost-effective and manufacturable solution for improving display optical characteristics.