OLED Pixel Reflective Assembly Redirects Lateral Light
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Solution Overview
Problem
In OLED display devices, light emitted from the organic luminescent layer under certain incident angles undergoes total reflection and is transmitted laterally into the pixel defining layer, leading to light dissipation rather than effective display, as the refractive indices of the organic luminescent layer and pixel defining layer are similar, causing light to deviate from the intended emission path.
Innovation Solution
A reflective assembly is introduced around the pixel defining layer, comprising a second insulation layer, a groove, and a reflective layer, which reflects light entering the pixel defining layer from the luminescent layer to exit from the pixel structure's surface, thereby converting laterally transmitted light into effective display beams.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the refractive index of the organic luminescent layer is similar to that of the pixel defining layer, then light transmission between layers is facilitated, but light beams deviate from the intended emission path and are laterally transmitted into the pixel defining layer, causing light dissipation
Solution Approach 1:
The patent converts the harmful lateral light transmission into beneficial upward light emission by introducing a reflective assembly. The reflective layer captures light that would otherwise be lost laterally and redirects it upward through the pixel aperture, transforming the harmful effect of refractive index matching into a beneficial light extraction mechanism
Solution Approach 2:
The reflective assembly acts as an intermediary between the organic luminescent layer and the pixel defining layer. It intercepts light at the interface where refractive index matching causes lateral transmission, and redirects it toward the desired emission direction, mediating the interaction between these two layers
2Loss of energy
If a reflective assembly is added to redirect laterally transmitted light, then light dissipation is reduced and display effect is improved, but device complexity increases
Solution Approach 1:
The reflective assembly is merged with the existing pixel defining layer structure. The reflective layer is positioned at the bottom of the pixel defining layer, utilizing the same structural footprint and integrating with the existing layer architecture, thereby adding minimal complexity while achieving light redirection
Solution Approach 2:
The reflective property is applied locally only where needed - at the interface between the organic luminescent layer and pixel defining layer where lateral light transmission occurs. This localized application of reflectivity addresses the specific problem area without requiring complex modifications throughout the entire device structure
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The reflective assembly enhances the display effect by redirecting laterally transmitted light, reducing light dissipation and improving the overall display performance of the OLED pixel structure.
Implementation Method 1
a reflective layer disposed at a side of the groove located at the second insulation layer to reflect the light transmitted through the pixel defining layer
Implementation Method 2
A voltage is applied between the first electrode layer and the second electrode layer to excite the organic luminescent layer to emit light
Implementation Method 3
the light emitted from the organic luminescent layer under a certain range of incident angles undergoes a total reflection on a surface of the organic luminescent layer
Implementation Method 4
because the refractive index of the organic luminescent layer is close to that of the pixel defining layer. These light beams are substantially laterally transmitted
Data Source
AI summary
A pixel structure, a display device having the pixel structure and a manufacturing method of the pixel structure are disclosed. The pixel structure comprises: a first insulation layer; a luminescent unit disposed on the first insulation layer and comprising a first electrode layer, a luminescent layer and a second electrode layer; a pixel defining layer configured for defining a pixel aperture, in which the luminescent unit is disposed; and a reflective assembly disposed around the pixel defining layer so as to reflect light entering the pixel defining layer from the luminescent layer to exit from an exit surface of the pixel structure. The reflective assembly is provided to reflect the light entering the pixel defining layer from the luminescent layer, so as to exit from the exit surface of the pixel structure. As a result, the light beams entering the pixel defining layer may be converted into effective beams for the pixel structure, thereby improving the display effect and reducing light dissipation.