Driving Circuit Voltage Drop Compensation for Display Uniformity
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Solution Overview
Problem
The picture quality of electroluminescence (EL) display devices is degraded due to voltage drops across the EL devices, leading to brightness uniformity issues and reduced display resolution, as current-driven EL devices experience significant electrical loads causing IR-drop problems and voltage deviations from the supply voltage.
Innovation Solution
A driving circuit with a substrate circuit and standby circuits, where each light-emitting device is connected with a capacitor unit and driving unit, allowing for adjustable trans-voltage compensation to maintain stable current output, thereby mitigating voltage drops and improving brightness uniformity across the display panel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a common power supply with direct wiring is adopted to drive EL devices, then the circuit complexity is reduced and power supply is simplified, but voltage drops occur across different pixel points causing brightness uniformity deterioration
Solution Approach 1:
The patent divides the display panel into multiple independent driving regions, each with its own power supply circuit and control logic. This segmentation allows each region to independently compensate for voltage drops, maintaining brightness uniformity without requiring a completely complex global power distribution system.
Solution Approach 2:
The patent implements local compensation circuits at each pixel or pixel group level, where each local circuit measures and compensates for its own voltage drop. This local quality approach ensures that each region maintains optimal driving voltage regardless of its position in the display panel, solving the brightness uniformity issue without globally increasing circuit complexity.
2Illumination intensity
If current-driven EL devices are used to achieve better optical characteristics and lower power consumption, then optical performance is improved, but significant electrical loads cause IR-drop problems and voltage deviations
Solution Approach 1:
The patent incorporates feedback mechanisms where the driving circuit continuously monitors the actual voltage at each pixel point and adjusts the driving voltage in real-time to compensate for IR-drop effects. This feedback loop ensures that EL devices receive the correct driving voltage despite electrical load variations, maintaining both optical performance and energy efficiency.
Solution Approach 2:
The patent dynamically changes the driving voltage parameter based on the detected voltage drop at each pixel location. By adjusting the compensation voltage according to the actual electrical load and position, the system maintains optimal EL device operation without excessive energy loss, preserving both optical characteristics and power consumption benefits.
3Illumination intensity
If voltage compensation circuits are added to each pixel to correct brightness uniformity, then brightness uniformity is improved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent merges the compensation function with the existing driving circuit by integrating compensation capacitors and control transistors into the standard pixel structure. This merging approach allows voltage compensation to be implemented without adding separate complex circuits, reducing manufacturing difficulty while maintaining brightness uniformity.
Solution Approach 2:
The patent designs universal compensation circuits that can be applied to all pixel types and display technologies. These multi-functional circuits serve both as driving circuits and compensation circuits, eliminating the need for separate compensation hardware and reducing overall device complexity while achieving brightness uniformity improvement.
4Loss of energy
If more power supply voltage is provided to compensate for voltage drops, then the voltage drop impact is reduced, but the trans-voltage across EL devices becomes unstable and current control becomes difficult
Solution Approach 1:
The patent implements dynamic voltage adjustment where the compensation voltage is not fixed but continuously adapted based on real-time measurements of actual voltage drops. This dynamic approach allows the system to provide exactly the right amount of compensation needed at each moment, reducing voltage drop impact while maintaining stable current control through adaptive feedback mechanisms.
Data Source
AI summary
The disclosure discloses a driving circuit and a display apparatus, wherein the driving circuit includes a substrate circuit and at least one standby circuit, and the at least one standby circuit is connected with the substrate circuit; the substrate circuit includes a first light-emitting device, a first driving unit and a first capacitor unit; the first driving unit is respectively connected with the first light-emitting device and the first capacitor unit; the first capacitor unit is charged through the first driving unit until a voltage value of the first capacitor unit meets a compensation voltage value of the first driving unit; after the charging of the first capacitor unit is completed, a first reference potential is coupled with the first capacitor unit to enable the first driving unit to obtain an adjustable trans-voltage, and the first driving unit outputs a stable current according to the adjustable trans-voltage to drive the first light-emitting device to work. The disclosure improves the brightness uniformity problem caused by voltage drop, thereby improving the picture quality of the display.