Application of Mini-LEDs with Microlens Arrays and Quantum Dot Film as Extra-Thin, Large-Area, and High-Luminance Backlight

Abstract

The demand for extra-thin, large-area, and high-luminance flat-panel displays continues to grow, especially for portable displays such as gaming laptops and automotive displays. In this paper, we propose a design that includes a light guide layer with a microstructure above the mini-light-emitting diode light board. The light control microstructure of concave parabel-surface microlens arrays on a light-emitting surface increases the likelihood of total internal reflection occurring and improved the uniformity merit function. We used a 17 in prototype with quantum-dot and optical films to conduct our experiments, which revealed that the thickness of the module was only 1.98 mm. When the input power was 28.34 watts, the uniformity, average luminance, and CIE 1931 color space NTSC of the prototype reached 85%, 17,574 cd/m2, and 105.37%, respectively. This module provided a flat light source that was extra thin and had high luminance and uniformity.

Microdisplays: Mini‐LED, Micro‐OLED, and Micro‐LED

“…[43] Chen et al integrated a microlens array with a brightness enhancement film on an ultra-thin mini-LED; the structure can improve the average luminance as well as the uniformity to 85%. [41] Lai et al demonstrated that the EQE of mini-LEDs can be improved by adopting atomic layer deposition (ALD) sidewall passivation. [44,45] In addition to the abovementioned methods, there are other functional films designed to improve uniformity, such as an advanced diffuser sheet [46] or a translucent layer composed of SiO 2 and TiO 2 .…”

“…Microlens array and brightness enhancement film [41] Spectral dichroic layer [42] Quantum rod enhancement film [43] ALD passivation [44,45] Uniformity Advanced diffuser sheet [46] Microlens array and brightness enhancement film [41] Translucent layer composed of SiO 2 /TiO 2 [47] SiO 2 /graphite bilayered packaging structure [48] Novel direct-lit mini-chip-scale packaged LED [49] Contrast ratio (HDR for AR)…”

“…Size Advanced diffuser sheet [46] Microlens array and brightness enhancement film [41] Resolution New pixel design [58] a)…”

“…Reduced halo effect [59] Color Multi-domain vertical alignment (MVA) LCDs [60] Microlens array and brightness enhancement film [41] QD white LED backlights [61] Quantum rod enhancement film [43] Cost Laser-assisted bonding (LAB) technologies [62] Stability ALD passivation [44] Flexible/see-through display IGZO TFT backplane [63] a) a) AR/VR-enhancement technologies package (CSP) method [49] have been discussed and proven to be effective. The approach to reducing power consumption has also been discussed by several groups.…”

“…The color gamut extends to 105.37% of the NTSC color triangles in the CIE1931 color space, much larger than that of the conventional LCDs (74.5%), as shown in Figure 4d. [41] The display performance, including FOV, resolution, and the range of the color gamut, was discussed in the previous section, showing that the high PPI, wide FOV, and small FWHM of each RGB color display are needed and are considered the final target. Although several methods have been developed to extend the FOV and the color gamut and increase the resolution, no optimal solution has been found as yet.…”