Backlight Drive Circuit Ghost Image Elimination
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Solution Overview
Problem
In liquid crystal displays using a time-division multiplexing mode, residual electric charges in LED strips can cause unintended lighting when switching between strips, leading to a 'ghost image' effect due to shared drive circuits and inefficient discharge mechanisms.
Innovation Solution
A backlight drive circuit with a discharging circuit connected to the anodes of LED strips, which actively discharges remaining electric charges during dead times, preventing residual voltage and ensuring accurate switching between LED strips.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a time-division multiplexing mode is used to share a drive circuit among multiple LED strips, then device complexity is reduced, but residual electric charges cause ghost image effects and reliability deteriorates
Solution Approach 1:
The patent extracts the discharging function from the main drive circuit by adding a separate discharging circuit with a dedicated discharging switch. This switch is specifically configured to discharge residual charges from LED strips during dead time periods, separating the charge discharge function from the normal drive function to eliminate ghost image effects while maintaining the simplified time-division multiplexing architecture
Solution Approach 2:
The patent applies preliminary action by discharging residual electric charges from LED strips before switching to the next strip during dead time periods. This proactive discharge prevents residual charges from causing ghost image effects in subsequent switching operations, ensuring clean transitions between LED strips
2Productivity
If LED strips are switched rapidly in time-division mode, then productivity is improved, but residual charges cause unintended lighting and loss of information occurs
Solution Approach 1:
The patent implements feedback by monitoring the switching state and controlling the discharging switch to operate during dead time periods when no LED strip is actively driven. This feedback mechanism ensures that residual charges are discharged at the appropriate moment, preventing unintended lighting and maintaining accurate charge state information for reliable switching
Data Source
AI summary
Disclosed are a backlight drive circuit, a backlight driving method, and a display device. The backlight drive circuit according to some embodiments of the disclosure includes: a plurality of LED strips configured to be powered in a time-division mode; a discharging circuit connected with anodes of the plurality of LED strips; and a first switch element connected with cathodes of the plurality of LED strips, wherein the first switch element has a first terminal connected with the cathodes of the plurality of LED strips, and a second terminal grounded, and the first switch element is configured to be turned on when any one of the plurality of LED strips is powered on.