Emi-Flective Display Device with Attribute of High Glare-Free-Ambient-Contrast-Ratio

Abstract

We have demonstrated the integration of an organic light emitting device (OLED) and a reflective liquid crystal display (R-LCD) which was termed an emi-flective display. The glare-free-ambient-contrast-ratio (GFA-CR) was used to evaluate the image quality of display devices under ambient light. Through integrating the OLED with R-LCD, the GFA-CR of the device achieved an improvement by a factor of 8 compared with that of the OLED alone. Moreover, the integrated R-LCD showed a GFA-CR of 100 : 1 within a viewing cone of 20 which can suppress the wash-out of OLED and is more power-saving in the sunlight. Therefore, an emi-flective display is a promising technique for mobile applications.

Transflective device with a transparent organic light‐emitting diode and a reflective liquid‐crystal device

“…Also, an emi-flective LCD combining the former structure with a nano-particle transflector in a unit cell has been reported to further enhance the A-CR. 9,10 To drive such a device, typically three transistors are needed in a subpixel, one for the RLCD and two for the OLED. Hence, the T-and R-modes can operate separately or simultaneously.…”

“…On the other hand, vertical integration of the OLED and reflective LCD (RLCD) holds promise for a transflective device with the advantages of high A-CR and large aperture ratio for both T-and R-modes. [7][8][9][10] In this paper, we demonstrate a hybrid device by using a vertical alignment (VA) or phasechanged guest-host (PCGH) RLCD stacking with an OLED to achieve high A-CR. Notably, the integrated device with the R-mode of the PCGH RLCD exhibits a higher transmittance and allows for simpler fabrication processes compared to the VA case due to its polarizer-free characteristics.…”