Low‐diffraction transparent micro light‐emitting diode displays with optimized pixel structure

• Published in: Journal of the Society for Information Display 2022-05, Vol.30 (5), p.395-403
• Main Authors: Yang, Qian, Yang, Zhiyong, Lan, Yi‐Fen, Wu, Shin‐Tson
• Format: Article
• Language: English
• Subjects: Angular resolution; Apertures; Blurring; diffraction suppression; Diffraction theory; Displays; Light diffraction; Light emitting diodes; Mathematical models; micro‐LED; pixel structure optimization; Pixels; transparent display; under‐display camera
• ISSN: 1071-0922; 1938-3657
• DOI: 10.1002/jsid.1122

Transparent displays suffer from background image blur due to light diffraction when passing through periodic pixel structures. A simple, reference‐image free and semi‐analytical model based on diffraction theory and human eye's angular resolution is proposed to quantitatively evaluate the diffraction effect of transparent displays. Several factors including object distance, resolution and aperture ratio are analyzed with our model to establish guidelines for minimizing the diffraction effect in transparent displays. By optimizing the pixel structures within a 2 × 2‐pixel size region, the relative diffraction intensity is reduced by 42% at the 50% aperture ratio regardless of pixel density, which is valuable for achieving diffraction‐less high resolution and low aperture ratio transparent displays with current fabrication technologies. A semi‐analytical model is built based on diffraction theory and human angular resolution to quantitatively evaluate the diffraction effect of transparent displays, including micro‐LED and OLED. By optimizing the pixel structures within a 2 × 2‐pixel size region, the relative diffraction intensity is reduced by 42% at the 50% aperture ratio regardless of pixel density.