Display Compensation Circuit for OLED Gamma Voltage IR-Drop Correction
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Solution Overview
Problem
The voltage drop (IR drop) in the power supply voltage signal due to long traces with high resistance results in reduced luminance of OLED display apparatuses, causing the display to appear dark.
Innovation Solution
A display compensation circuit integrated on a circuit board, comprising a generation circuit and a calculation circuit, generates and adjusts gamma voltage signals to compensate for the power supply voltage signal, ensuring precise and synchronized luminance across the display panel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the power supply voltage signal is transmitted through a long trace with high resistance, then the power management integrated circuit can be disposed on the main circuit board, but a voltage drop occurs resulting in reduced luminance
Solution Approach 1:
The patent applies preliminary action by pre-calculating compensation values for voltage drop in the gamma voltage signals. The compensation circuit adds these pre-calculated values to the power supply voltage signal before it reaches the pixel drive circuit, thereby compensating for the voltage drop that will occur during transmission through the long trace. This resolves the contradiction by addressing the energy loss before it affects the luminance output.
2Ease of manufacture
If the power supply voltage signal is transmitted through a long trace, then the power management integrated circuit can be disposed on the main circuit board, but the trace has large resistance causing voltage drop
Solution Approach 1:
The patent implements feedback by using the actual power supply voltage signal (which already includes the voltage drop from the long trace) as a reference for generating compensated gamma voltage signals. The compensation circuit calculates the difference between the expected voltage and the actual voltage, then adds this difference to compensate for the drop. This feedback mechanism ensures reliable voltage signal delivery despite the long trace and high resistance.
3Length of stationary object
If the power supply voltage signal voltage is low due to voltage drop, then the trace can be long connecting PMIC to display panel, but the display picture becomes dark
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the gamma voltage signals based on the actual power supply voltage signal. The compensation circuit modifies the voltage parameters of the gamma signals to account for the voltage drop, ensuring that the pixel drive circuits receive the correct compensated voltage levels. This allows long traces to be used without sacrificing display luminance.
Data Source
AI summary
Embodiments of this application provide a display compensation circuit, a source circuit board, a display module, and a display apparatus, and relate to the field of display technologies. The display compensation circuit may be integrated on a circuit board, the display compensation circuit includes a generation circuit and a calculation circuit that are electrically connected, and the generation circuit is configured to output a first reference gamma voltage and a second reference gamma voltage. The calculation circuit is configured to: receive a power supply voltage signal, and the first reference gamma voltage and the second reference gamma voltage that are from the generation circuit; and output a first gamma voltage signal and a second gamma voltage signal.