OLED Crosstalk Prevention via Anode Voltage Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Organic light emitting diode (OLED) display devices experience crosstalk phenomena, leading to decreased resolution, incorrect color display, and reduced contrast ratios due to light emission from non-emitting or low-luminance organic light emitting elements, which existing technologies have not adequately addressed without increasing structural complexity.
Innovation Solution
A display device design that includes a control unit to apply electric potential to pixel circuits, using a control element to manage emission luminance and an application unit that applies a voltage less than or equal to the threshold voltage to the anode electrode, maintaining an electric potential difference between the anode and cathode electrodes to prevent light emission during vertical scanning periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a crosstalk preventing electrode is arranged at the periphery of each organic light emitting element, then crosstalk is prevented, but the structure becomes complex
Solution Approach 1:
The patent combines the crosstalk prevention function with the existing pixel circuit structure by integrating the application unit into the pixel circuit. This merging approach eliminates the need for separate crosstalk preventing electrodes while achieving the same crosstalk prevention effect through voltage control of the anode electrode.
Solution Approach 2:
The anode electrode is given multiple functions: it serves as both the light-emitting electrode and the crosstalk prevention electrode. By controlling the voltage of the anode electrode to be equal to or lower than the threshold voltage during non-emission periods, the same structure prevents crosstalk without requiring additional components.
2Manufacturing precision
If the anode electrode voltage is controlled to prevent crosstalk, then image quality improves, but additional control mechanisms are required
Solution Approach 1:
The control function for crosstalk prevention is merged into the pixel circuit itself through the application unit, which is integrated with the drive circuit. This allows the same control mechanism to manage both light emission and crosstalk prevention without requiring separate control systems.
Solution Approach 2:
The application unit applies a voltage to the anode electrode in advance before the light emission period begins, ensuring that the voltage is already at the appropriate level (equal to or lower than threshold voltage) to prevent crosstalk. This preliminary action eliminates the need for complex real-time monitoring and adjustment mechanisms.
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 solution effectively prevents crosstalk in OLED display devices by maintaining the organic light emitting elements in a non-emission state, thereby enhancing image resolution, accuracy, and contrast ratio without increasing structural complexity.
Implementation Method 1
an organic light emitting element including a light emitting layer that emits light by a current flowing between an anode electrode and a cathode electrode
Implementation Method 2
an application unit that applies a voltage of less than or equal to a threshold voltage of the organic light emitting element to the anode electrode before a start of the second period. The organic light emitting element has internal capacitance to maintain an electric potential difference between the anode electrode, the electric potential of which is applied by the application unit, and the cathode electrode
Data Source
AI summary
Provided is an OLED display device preventing an occurrence of a crosstalk using a simple structure.A display device includes: a display unit that includes a plurality of pixel circuits each including an organic light emitting element; a control unit that applies electric potential to the pixel circuits for a first period, and that controls emission luminance of the organic light emitting elements for a second period after the first period; and an application unit that applies a voltage of less than or equal to a threshold voltage of the organic light emitting element before a start of the second period in which the organic light emitting element has internal capacitance to maintain an electric potential difference between the anode electrode and the cathode electrode for a vertical scanning period in which a displayed image to be refreshed when the control unit controls the organic light emitting element not to emit light.