Gate Driver Current Sensing for Display Devices
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Solution Overview
Problem
Conventional current sensing methods in display devices require longer sensing times due to the sequential process of sensing current in blocks of pixels, leading to inefficiencies and visibility issues during the sensing mode.
Innovation Solution
A display device architecture that includes a sensing circuit with a resistor and switch connected to a power line, allowing for sequential sensing of current in units of pixel blocks along a column direction, bypassing the light-emitting element to suppress light emission and reduce sensing time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional current sensing method is used to sense current in blocks of pixels sequentially, then current sensing compensation can be performed, but sensing time becomes longer
Solution Approach 1:
The display panel pixels are divided into multiple blocks (first block and second block) along the column direction. The sensing circuit sequentially senses current in each block independently by applying sensing data to specific blocks while maintaining other blocks in display mode. This segmentation allows parallel processing of sensing operations across different blocks, significantly reducing total sensing time while maintaining measurement precision for each block.
2Reliability
If current sensing is performed during sensing mode, then compensation for pixel deterioration can be achieved, but light emission occurs causing visibility problems
Solution Approach 1:
The display device alternates between display mode and sensing mode in a periodic fashion. During sensing mode, sensing data is applied to pixel blocks and current is sensed for compensation purposes. During display mode, normal image data is applied and light emission occurs. This periodic switching allows current sensing compensation to be performed without continuous light emission, resolving the visibility problem while maintaining compensation reliability.
Solution Approach 2:
The display panel is divided into multiple blocks that can be independently controlled. While one block is in sensing mode for current measurement, other blocks can remain in display mode emitting light. This spatial segmentation allows sensing operations to be performed on specific blocks without requiring the entire display to be in sensing mode, thereby maintaining visibility while enabling compensation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly shortens the sensing time, improves consistency, and resolves visibility problems by allowing current sensing without light emission during the sensing mode.
Implementation Method 1
a sensing circuit configured to sense current flowing through the power line
Data Source
AI summary
A display device comprises: pixels connected to a power line to which a pixel driving voltage is supplied; data lines that extend in a first direction and are connected to the pixels, the data lines applying data voltages of an image to the pixels; gate lines that are connected to the pixels and extend in a second direction, the gate lines applying gate signals to the pixels; a data driver configured to supply the data voltages to the data lines during a display mode, and to supply sensing data to the data lines during a sensing mode; a gate driver configured to supply the gate signals to the gate lines; and a sensing circuit configured to sense current flowing through the power line that is connected to a subset of pixels from the pixels during the sensing mode, the subset of pixels arranged along the first direction.