Image quality affected by diffraction of aperture structure arrangement in transparent active-matrix organic light-emitting diode displays

Abstract

Transparent display is one of the main technologies in next-generation displays, especially for augmented reality applications. An aperture structure is attached on each display pixel to partition them into transparent and black regions. However, diffraction blurs caused by the aperture structure typically degrade the transparent image when the light from a background object passes through finite aperture window. In this paper, the diffraction effect of an active-matrix organic light-emitting diode display (AMOLED) is studied. Several aperture structures have been proposed and implemented. Based on theoretical analysis and simulation, the appropriate aperture structure will effectively reduce the blur. The analysis data are also consistent with the experimental results. Compared with the various transparent aperture structure on AMOLED, diffraction width (zero energy position of diffraction pattern) of the optimize aperture structure can be reduced 63% and 31% in the x and y directions in CASE 3. Associated with a lenticular lens on the aperture structure, the improvement could reach to 77% and 54% of diffraction width in the x and y directions. Modulation transfer function and practical images are provided to evaluate the improvement of image blurs.

31-2: See-through Image Blurring of Transparent OLED Display: Diffraction Analysis and OLED Pixel Optimization

“…This kind of blurring can significantly degrade see-through image quality, but cannot be explained by simple specifications, like brightness, contrast etc., In fact, it was reported to be in connection with diffraction caused by OLED pixels [6,7]. Figure 1(a) shows what user perceived when an LED lamp was placed behind a T-OLED display [6] [6], in which typical diffraction pattern was perceived. References [6] and [7] succeeded to quantitatively figure out this pattern with Fraunhofer diffraction theory.…”

“…Simple specifications, like brightness, contrast etc., of see-through image have been investigated by prior studies to determine the image quality [5]. However, latest studies stated that see-through background image is blurred with certain degree when T-OLED display is used [6,7]. This kind of blurring can significantly degrade see-through image quality, but cannot be explained by simple specifications, like brightness, contrast etc., In fact, it was reported to be in connection with diffraction caused by OLED pixels [6,7].…”

“…However, latest studies stated that see-through background image is blurred with certain degree when T-OLED display is used [6,7]. This kind of blurring can significantly degrade see-through image quality, but cannot be explained by simple specifications, like brightness, contrast etc., In fact, it was reported to be in connection with diffraction caused by OLED pixels [6,7]. Figure 1(a) shows what user perceived when an LED lamp was placed behind a T-OLED display [6] [6], in which typical diffraction pattern was perceived.…”

43‐3: Pixel Structure Evaluation Regarding See‐through Image Quality for Transparent Displays: A Study Based on Diffraction Calculation and Full‐Reference Image Quality Assessment

“…In transparent displays, see-through images are fused with displayed images to be observed, thus qualities of displayed and see-through images are both concerned. In previous studies, transparent OLED or LC displays that adopt transparent windows were found to generate blurred see-through images due to pixel array diffraction, like that shown in Figure 1(a) [2][3][4]. For this blurring issue, we have proposed a calculation method [3,4], by using which, blurred seethrough image can be accurately figured out according to the pixel structure and viewing condition.…”

“…In previous studies, transparent OLED or LC displays that adopt transparent windows were found to generate blurred see-through images due to pixel array diffraction, like that shown in Figure 1(a) [2][3][4]. For this blurring issue, we have proposed a calculation method [3,4], by using which, blurred seethrough image can be accurately figured out according to the pixel structure and viewing condition. After acquiring this effective calculation method, we are also interested in assessing the quality of see-through images, so that pixel structure can be quantitatively evaluated regarding seethrough image quality.…”