LED Display Voltage Control for Gradation Without Data Bit Increase
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Solution Overview
Problem
Display devices, such as LEDs, face challenges in achieving uniform image quality and adequate gradation expression, often requiring more data bits to improve gradation at the expense of image quality.
Innovation Solution
An LED device and driving method that individually vary voltage applied to pixels using a data driver with a panel driving circuit and sensing circuit, allowing for the output of different voltages to sub-pixels to enhance gradation expression without increasing data bits, by sharing voltage between data lines and reference lines and using switches to control voltage levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If more data bits are used to improve gradation expression, then gradation expression area is improved, but device complexity and power consumption increase
Solution Approach 1:
The patent changes the voltage parameter dynamically by outputting different reference voltages (first reference voltage and second reference voltage) depending on the sub-pixel type and display requirements. This allows fine-grained control of luminance and gradation expression without increasing the number of data bits, thereby resolving the contradiction between gradation precision and device complexity
Solution Approach 2:
The reference voltage is made dynamic rather than fixed. The data driver selectively outputs different reference voltages based on real-time display needs, enabling adaptive control of sub-pixel luminance. This dynamic adjustment allows the system to achieve superior gradation expression with the same data bit depth, avoiding the need to increase device complexity
2Device complexity
If standard voltage output is used for all sub-pixels, then circuit simplicity is maintained, but image uniformity and luminance control are insufficient
Solution Approach 1:
The patent applies local quality by providing different reference voltages to different sub-pixels based on their specific requirements. The data driver outputs a first reference voltage for certain sub-pixels and a second reference voltage for others, allowing each sub-pixel to receive the optimized voltage for its display characteristics. This localized voltage control improves image uniformity and luminance expression while maintaining relatively simple circuit architecture
Solution Approach 2:
The reference voltage output is segmented into multiple levels (first reference voltage and second reference voltage) that can be selectively applied to different sub-pixels. This segmentation of the voltage control function allows the system to achieve precise local control without requiring a completely complex voltage generation system, thus balancing image quality with circuit simplicity
3Use of energy by stationary object
If fixed reference voltage is applied, then power consumption is reduced, but luminance control and gradation expression are limited
Solution Approach 1:
The reference voltage is dynamically adjusted based on display requirements rather than remaining fixed. The data driver selects between different reference voltages to optimize luminance control and gradation expression when needed, while maintaining lower power consumption during standard operation. This dynamic approach allows the system to achieve high luminance control performance without continuously consuming excessive power
Solution Approach 2:
The system changes the reference voltage parameter selectively to achieve better luminance control and gradation expression. By outputting different reference voltages (first and second reference voltages) based on sub-pixel type and display mode, the system optimizes light output without requiring continuous high power consumption, thus resolving the contradiction between luminance control and energy usage
Data Source
AI summary
A light emitting display (LED) device can include a display panel configured to display an image; and a data driver including a panel driving circuit configured to drive the display panel and a panel sensing circuit configured to sense a condition of the display panel, in which the panel driving circuit includes a first data voltage output circuit to output a voltage to both of a first data line and a first reference line of the display panel to display black on a first sub-pixel included in the display panel.