Source Driver Bias Current Adjustment for Display Power Reduction
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Solution Overview
Problem
As panel resolution increases, the number of output channels in source drivers grows, leading to wider display panels and increased wiring resistance, resulting in uneven signal phase delays and unnecessary power consumption due to over-driving of middle channels to compensate for edge channels.
Innovation Solution
The source driver adjusts bias current amplitudes locally based on resistance values of output channels, dividing them into sectors with corresponding bias current settings to match resistance differences, ensuring optimal power usage without over-driving.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the line width and line interval of the source output channel are reduced to meet narrow frame demands, then the display panel frame width is reduced, but the wiring resistance of the source output channel increases significantly
Solution Approach 1:
The patent applies local quality by providing different bias current amplitudes to different output channels based on their specific resistance characteristics. Edge channels receive larger bias current amplitudes while middle channels receive smaller amplitudes, matching each channel's local resistance conditions rather than using a uniform bias current for all channels.
2Reliability
If a uniform bias current is set according to edge channel requirements, then the edge channels can operate normally, but the middle channels experience over-driving and increased power consumption
Solution Approach 1:
The patent implements local quality by customizing the bias current amplitude for each output channel according to its resistance value. This ensures that each channel receives precisely the current it needs for reliable operation without excessive current being applied to low-resistance middle channels, thereby eliminating over-driving and reducing unnecessary power consumption.
Solution Approach 2:
The patent applies dynamics by making the bias current amplitude adjustable and adaptable to different channel conditions. The bias current amplitude is dynamically set based on the resistance values of different output channels, allowing the system to optimize power distribution according to actual operating conditions rather than using a fixed uniform current.
3Measurement precision
If the number of output channels is increased to meet higher panel resolution, then the display resolution is improved, but the Fan-out region area increases causing wider bottom frame
Solution Approach 1:
The patent applies parameter changes by modifying the bias current amplitude parameter according to the resistance characteristics of different output channels. This allows the system to accommodate increased channel density in the Fan-out region by optimizing the electrical parameters (bias current) to compensate for the effects of reduced line width and increased resistance, enabling higher resolution without proportionally increasing the Fan-out region area.
Data Source
AI summary
Provided are a source driver and a driving method thereof, an array substrate and a display apparatus. The source driver comprises a plurality of output channels, a plurality of output amplifiers corresponding to the plurality of output channels and a bias circuit configured to supply the output amplifiers with bias currents. The driving method comprises: acquiring resistance values of the output channels (101); and for each of the output channels, setting an amplitude of the bias current supplied to the output amplifier corresponding to the output channel from the bias circuit, according to the resistance value of the respective output channel, so that the bias current of the output amplifier corresponding to the output channel with a larger resistance value being greater than or equal to the bias current of the output amplifier corresponding to the output channel with a smaller resistance value in amplitude (102). Amplitudes of bias currents in different output channels are adjusted locally/partly, so that a power consumption of the source driver is decreased under a normal condition for driving and displaying of a display panel and in turn a power consumption of the entire display apparatus is reduced.