Data driving circuit and display including the same
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing display devices face challenges in achieving accurate luminance and grayscale due to offset voltages in operational amplifiers, which hinder the development of large-sized LED display devices.
Innovation Solution
A data driving circuit with a gamma voltage generation circuit that includes operational amplifier circuits connected to different points of a resistor string, employing offset elimination methods like auto-zeroing and chopping to stabilize output signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a gamma voltage generation circuit uses operational amplifier circuits to distribute power supply voltage and generate gamma reference voltage, then grayscale expression capability is improved, but offset voltages in the operational amplifiers cause inaccurate luminance and grayscale control
Solution Approach 1:
The patent applies preliminary action by performing offset voltage elimination before the operational amplifier circuits distribute the power supply voltage. The offset elimination circuit measures and compensates for offset voltages in advance, ensuring that subsequent voltage distribution and grayscale generation are not affected by these offsets, thereby achieving accurate luminance and grayscale control
Solution Approach 2:
The patent introduces an intermediary offset elimination circuit that acts as a mediator between the power supply voltage source and the operational amplifier circuits. This intermediary circuit measures the offset voltages and generates compensation signals that are fed back to eliminate the offsets, thereby improving both grayscale expression capability and luminance accuracy without sacrificing reliability
2Area of stationary object
If LED pixels are disposed in large numbers to create large-sized display devices, then display size is improved, but offset voltage errors accumulate and degrade image quality
Solution Approach 1:
The patent applies segmentation by dividing the large display device into multiple independent gamma voltage generation circuits, each serving a specific region or module. Each circuit independently eliminates offset voltages and generates accurate gamma reference voltages for its designated area, preventing error accumulation across the entire large display and maintaining image quality throughout
Solution Approach 2:
The patent performs preliminary offset voltage elimination in each segmented gamma voltage generation circuit before the voltages are distributed to LED pixels. By compensating for offsets in advance in each segment, the system ensures accurate luminance control across the entire large display device, preventing degradation of image quality even as display size increases
Data Source
AI summary
The present disclosure relates to an offset elimination operation of an internal operational amplifier of a data driving circuit and relates to a technique that applies different offset elimination methods for each position of an operational amplifier.