Using Stacked Inverse-Reflective Cup Structure to Improve Vertical Light Output and Ambient Contrast Ratio of Light Emitting Diode Display Device

For outdoor displays, high ambient contrast ratio (ACR) and high brightness in the vertical direction of the display screen are crucial. So far, it remains challenging to maintain high ACR while improving vertical brightness output for outdoor display devices. Therefore, we propose a stacked inverse-reflective cup structure to address this problem. The structure comprises a transparent inverse-reflective cup encapsulating the chip and a bottom layer filled with high-scattering TiO
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scattering layer and a top layer filled with high-absorption graphite extinction layer. By utilizing optical software for simulation, we optimized the stacked inverse-reflective cup structure and revealed the mechanism for achieving low reflectance and high vertical brightness output for the device. By adjusting the tilt angle of the transparent inverse-reflective cup and the thickness of the graphite extinction layer, the vertical output and ACR of the chip can be selectively adjusted. Compared to devices with transparent packaging, devices with stacked inverse-reflective cup structures achieved high ACR, increasing from 114 to 563, a 393% increase (ambient light of 10,000 Lux). At the same time, the vertical brightness output was improved by 113.4%, compared to devices with transparent packaging. Due to the simplicity of the stacked inverse-reflective cup structure, it can be easily integrated into outdoor display devices, achieving excellent ACR and higher vertical brightness output, meeting the extensive application needs of outdoor large-screen displays.