Display Device Sensing Block Calibration for Luminance Uniformity
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Solution Overview
Problem
Existing display devices face challenges in maintaining uniform luminance across the screen due to offset variations among sensing blocks, particularly after changes in temperature or environmental conditions, leading to a 'block dim' phenomenon where luminance differs between areas driven by source drive ICs, and current calibration methods are inefficient as they require separate power-off sequences.
Innovation Solution
A display device that performs real-time calibration by using a source drive IC with a sensing block and a switch to disconnect the pixel and sensing block during display driving, allowing for the application of a test voltage or current to obtain calibration data, thereby compensating for characteristic changes in sensing blocks during active use, and utilizing a separate power source for calibration to avoid interference from pixel current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If calibration is performed using a separate power-off sequence, then calibration accuracy is improved, but power-off sequence time increases and real-time compensation is lost
Solution Approach 1:
The patent applies preliminary action by performing calibration during the power-off sequence before the display turns on, so that compensation values are ready in advance. The timing controller executes calibration instructions stored in memory during the power-off period, preparing compensation data before normal display operation begins, thus avoiding time loss during active display while maintaining calibration accuracy.
Solution Approach 2:
The patent achieves continuity of useful action by making the calibration process repeatable at every power-off sequence. The timing controller continuously updates compensation values during each power-off period, ensuring that calibration is performed regularly without interrupting normal display operation, thus maintaining both accuracy and real-time compensation capability.
2Area of stationary object
If multiple sensing blocks are used to drive different areas, then display coverage is improved, but luminance uniformity deteriorates due to offset variations among sensing blocks
Solution Approach 1:
The patent applies feedback by using sensing blocks to detect pixel characteristics (such as threshold voltage and mobility) in different display areas, then using the timing controller to calculate compensation values based on this feedback. The compensation values are used to adjust image data, creating a closed-loop system that corrects luminance non-uniformity caused by variations among multiple sensing blocks while maintaining full display coverage.
3Adaptability or versatility
If ADC characteristics change with temperature, then environmental adaptability is improved, but sensing accuracy deteriorates due to output value shifts
Solution Approach 1:
The patent applies parameter changes by detecting shifts in ADC output characteristics as environmental parameters (temperature) change. The timing controller monitors these parameter changes and adjusts compensation values accordingly, allowing the system to adapt to different environmental conditions while maintaining sensing accuracy through dynamic compensation rather than static ADC operation.
Data Source
AI summary
The display device according to the present disclosure may comprise a display panel equipped with a plurality of pixels connected to data lines and sensing lines; a source drive IC configured to provide a data voltage to a pixel through the sensing line and equipped with a sensing block obtaining sensing data related to driving characteristics of the pixel using a signal input through the sensing line; a switch configured to control a connection via the sensing line between the pixel and the sensing block; and a power source configured to provide a test voltage or a test current to the sensing block, and the source drive IC may obtain calibration data for the sensing block by using the test voltage or the test current in a state that the switch disconnects the pixel and the sensing block.