Display Output Circuit With Dynamic Current Mirrors for High-Speed Driving
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-speed driving display apparatuses face a trade-off between power consumption and data charging/discharging characteristics due to increased main bias current for higher output slew rates.
Innovation Solution
A display apparatus with a timing controller generating current mirror control information and an output circuit comprising mirroring current generators and current mirrors to selectively control the slew rate without increasing the main bias current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the main bias current supplied to the output circuit is increased to increase the output slew rate, then the data charging/discharging characteristic is improved, but the power consumption increases
Solution Approach 1:
The patent implements dynamic control of the output circuit by selectively activating first and second current mirrors based on the transition amount of image data. When the transition amount exceeds a threshold, the current mirrors are activated to increase the output slew rate; when it is below the threshold, they remain inactive to maintain low power consumption. This dynamic adaptation resolves the contradiction between speed and energy usage.
Solution Approach 2:
The patent changes the operational parameters of the output circuit by adjusting the current mirror activation state according to the image data transition amount. The timing controller generates current mirror control information that dynamically modifies the current mirror's contribution to the output current, thereby changing the effective slew rate parameter based on actual display needs rather than maintaining a fixed high-current state.
2Productivity
If the main bias current is increased to satisfy the data charging/discharging characteristic for high-speed driving, then the output slew rate is improved, but the power consumption characteristic deteriorates
Solution Approach 1:
The patent applies partial action by selectively activating the current mirror only when necessary (when image data transition amount exceeds the threshold). Instead of continuously operating the current mirror at full capacity, the system applies its effect only during periods of high data transition, thereby achieving improved data charging/discharging characteristics only when needed while avoiding unnecessary energy loss during low-activity periods.
Data Source
AI summary
A display apparatus includes a display panel including pixels, a timing controller configured to generate current mirror control information, based on an amount of transition of image data to be written in the pixels, and an output circuit configured to output a target data voltage, corresponding to the image data, to a data output channel connected to one of the pixels, wherein the output circuit includes a mirroring current generator configured to generate a mirroring current and an amplifier circuit including a pull-up transistor including a gate electrode connected to a first control node, a first current mirror configured to supply the mirroring current to the first control node according to the current mirror control information, a pull-down transistor including a gate electrode connected to a second control node, and a second current mirror configured to supply the mirroring current to the second control node.