OLED Display Reference Voltage Line for Bezel Reduction
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Solution Overview
Problem
Organic light emitting diode (OLED) display devices experience luminance differences between edge and central pixels due to varying parasitic capacitance, leading to inefficient driving and increased bezel size as the number of voltage supply wires increases.
Innovation Solution
Incorporating a dummy area adjacent to the display area with a reference voltage supplying line and initializing voltage lines, which are connected to the wire area, to equalize parasitic capacitance and reduce bezel size by positioning these lines in a bent bar shape extending in the column direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple voltage supply wires are added to drive each pixel efficiently, then the driving efficiency is improved, but the bezel size increases
Solution Approach 1:
The patent combines multiple voltage supply functions into a single integrated wire structure. The first wire supplies both the first voltage to the first electrode and the second voltage to the second electrode, eliminating the need for separate dedicated wires and reducing bezel size while maintaining efficient pixel driving.
Solution Approach 2:
The first wire is designed to perform multiple functions simultaneously: supplying the first voltage to the first electrode, supplying the second voltage to the second electrode, and serving as a reference voltage line. This multi-functionality reduces the total number of wires required and minimizes bezel area.
2Ease of manufacture
If data line and driving voltage line are positioned at opposite sides of pixels, then signal routing is simplified, but parasitic capacitance varies between edge and central pixels causing luminance differences
Solution Approach 1:
The patent applies different voltage levels to different parts of the same wire structure. The first wire supplies the first voltage to the first electrode and the second voltage to the second electrode, creating localized voltage differences that compensate for position-dependent parasitic capacitance variations between edge and central pixels.
Solution Approach 2:
The patent changes the voltage parameter along the wire by supplying different voltages (first voltage and second voltage) to different electrodes through the same wire. This voltage parameter variation compensates for the parasitic capacitance differences caused by pixel position, ensuring uniform luminance across the display.
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
This configuration prevents or reduces luminance differences across the display and minimizes bezel size by ensuring consistent voltage distribution and reducing wire complexity.
Implementation Method 1
parasitic capacitance of pixels at left and right edges of the organic light emitting diode display may be different than parasitic capacitance of a pixel at a central portion
Implementation Method 2
electrons injected from one electrode and holes injected from another electrode are combined in the organic light emitting layer to generate excitons. The generated excitons are changed (e.g., transition) to a ground state from an excited state, releasing energy to emit light
Data Source
AI summary
An embodiment provides a display device including: a display area including a plurality of pixels; a dummy area adjacent to an edge of the display area; a reference voltage supplying line in the dummy area and to supply a reference voltage; and a wire area in which a wire to supply a signal applied to the display area is located, wherein a pixel of the plurality of pixels includes a light emitting diode coupled between a driving voltage line to which a driving voltage is to be applied and a common voltage line to which a common voltage is to be applied, and a driving transistor coupled between the driving voltage line and the light emitting diode, and wherein the reference voltage is to be supplied to a first electrode of the driving transistor.