Fabry-Perot Color Filter to Minimize Angle Dependence for Viewing Display

OVERVIEW

Optical spectrum filter with reduced angle dependence for display technologies

• Minimizes color shift at different viewing angles, improving display accuracy
• LCDs, flat-panel displays, LEDs, wearable displays, CMOS image sensors

BACKGROUND

Optical spectrum filters, like color filters, are crucial components in various display technologies, including LCDs, flat-panel displays, and CMOS image sensors. Traditional optical filters use pigment-based methods to achieve color differentiation, typically involving multiple manufacturing steps that increase complexity and cost. Furthermore, these pigment-based filters exhibit considerable angle dependence, causing color shifts when viewed from different angles. This unwanted angle dependence is particularly problematic for high-precision imaging and display applications. Previous attempts, such as Fabry-Perot based etalon filters, have not fully resolved this issue and still present significant angle dependence. There is a need for a new spectrum filter technology that can offer high transmission efficiency, minimal angle dependence, and simplified manufacturing processes to suit modern display requirements.

INNOVATION

Researchers at the University of Michigan have developed an optical spectrum filtering device using an interference filter assembly comprising a high refractive index dielectric material, such as in a Fabry-Perot based resonator structure, to minimize angle dependence. This technology reduces color shifts, maintaining the filtered output's wavelength range within 50 nm across incidence angles from 0° to 90°. This is achieved by sandwiching the dielectric material between parallel reflective surfaces, potentially using metals or distributed Bragg reflectors. This innovative approach also simplifies the manufacturing process by eliminating multiple steps and reducing chemical waste. Potential real-world applications include LCDs, flat-panel displays, LEDs, wearable displays, and CMOS sensors, providing high transmission efficiency and consistent color output across various viewing angles. This advancement presents a significant step forward in display technology, ensuring more accurate and reliable imaging.

ADDITIONAL INFORMATION

US9261753 "Spectrum filtering for visual displays and imaging having minimal angle dependence"