Dual-LED Subpixel Display for Switchable Viewing Angle Control
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Solution Overview
Problem
Existing light emitting display devices lack the ability to selectively restrict viewing angles and maintain stable grayscale output, particularly in vehicle applications where image reflection on windshields can obstruct drivers' views and privacy concerns arise.
Innovation Solution
A light emitting display device with a display panel comprising subpixels that include first and second light emitting diodes, each with a dedicated lens, a driving transistor, and a capacitor, allowing for independent control of viewing angles through differential initialization of anode electrodes and driving currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the viewing angle is restricted to protect privacy and prevent windshield reflection, then safety and privacy are improved, but the device loses adaptability to different viewing conditions
Solution Approach 1:
The patent implements dynamic viewing angle control by switching between two light emitting diodes with different viewing angle characteristics based on operational mode. In normal mode, the first light emitting diode provides a wide viewing angle for general visibility. In vehicle mode, the second light emitting diode provides a narrow viewing angle to prevent windshield reflection and protect privacy. This dynamic switching resolves the contradiction by adapting the viewing angle to specific operational conditions rather than fixing it permanently.
Solution Approach 2:
The patent changes the viewing angle parameter by selecting different light emitting diodes with inherently different viewing angle properties. The first light emitting diode is designed with a first viewing angle suitable for general display, while the second light emitting diode is designed with a second viewing angle specifically optimized to prevent windshield reflection in vehicle applications. This parameter change approach allows the system to optimize viewing angle characteristics for different operational contexts.
2Adaptability or versatility
If dual light emitting diodes with different viewing angles are implemented, then viewing angle control capability is improved, but device complexity increases
Solution Approach 1:
The patent merges two light emitting diodes within a single pixel structure, where each light emitting diode has its own anode electrode but shares common control circuitry. The first and second light emitting diodes are integrated into the same pixel, with their respective anode electrodes connected to the driving transistor through different switching transistors. This merging approach achieves viewing angle control functionality while minimizing structural complexity by sharing common components rather than implementing completely separate display structures.
Solution Approach 2:
The driving transistor and capacitor serve multiple functions: they control both the first and second light emitting diodes, manage initialization voltages for different anode electrodes, and enable mode switching between wide and narrow viewing angles. This multi-functionality reduces the need for separate control circuits for each light emitting diode, thereby limiting the increase in device complexity while maintaining viewing angle control capability.
3Reliability
If differential initialization voltages are applied to anode electrodes, then grayscale stability is improved, but circuit complexity increases
Solution Approach 1:
The patent applies preliminary initialization voltages to the anode electrodes of the light emitting diodes before the display operation begins. The capacitor is initialized with a first voltage, and the anode electrodes are initialized with a second voltage that is different from the capacitor's voltage. This preliminary initialization ensures that the grayscale output remains stable during operation by pre-setting the electrical conditions, thereby improving reliability without requiring complex real-time adjustment circuits.
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 solution enables selective switching of viewing angles and stable grayscale output, addressing privacy and safety concerns by controlling image reflection and maintaining consistent luminance.
Implementation Method 1
a first lens configured to refract light emitted from the first light emitting diode
Data Source
AI summary
A light emitting display device includes a display panel in which a plurality of pixels is disposed, each of the plurality of pixels includes a plurality of sub pixels, each of the plurality of sub pixels includes: a first light emitting diode configured to emit light by a first driving current; a first lens which refracts light emitted from the first light emitting diode; a second light emitting diode configured to emit light by a second driving current; a second lens which refracts light emitted from the second light emitting diode; a driving transistor configured to control the driving currents, and a capacitor which is connected to the driving transistor, and each of an anode electrode of the first light emitting diode and an anode electrode of the second light emitting diode may be initialized to a voltage different from a voltage which is applied to the capacitor.