Touch Display Power Circuit Voltage Drop Compensation
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Solution Overview
Problem
Touch display devices that perform display driving and touch driving in a time-division manner often experience a drop in high-potential voltage output levels during display driving intervals following touch driving intervals, leading to image abnormalities such as horizontal bands, especially as the size of the display panel increases.
Innovation Solution
A touch display device with a controller that outputs synchronization signals to adjust the high-potential voltage output, setting it higher during display driving intervals and lower during touch driving intervals, and a data driving circuit that upwardly adjusts image data gradations to maintain consistent data voltage levels across sub-pixels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If display driving and touch driving are performed in a time-division manner, then the touch display device can provide both display and touch sensing functions, but the output level of high-potential voltage drops during display driving intervals after touch driving intervals
Solution Approach 1:
The power output circuit dynamically adjusts the high-potential voltage output level based on the driving interval state. During display driving intervals following touch driving intervals, the circuit detects the state and automatically raises the output level to compensate for the voltage drop, ensuring stable operation without manual intervention
Solution Approach 2:
The controller monitors the driving interval state and provides feedback control to the power output circuit. When a display driving interval is detected after a touch driving interval, the controller signals the power output circuit to adjust the high-potential voltage level, creating a closed-loop control system that maintains voltage stability
2Area of stationary object
If the size of the display panel increases, then the display area and resolution improve, but the load of the display panel increases causing image abnormalities
Solution Approach 1:
The power output circuit changes the output voltage parameter dynamically based on the panel size and load conditions. For larger display panels that exhibit greater voltage drops, the circuit automatically increases the high-potential voltage output level during critical display driving intervals, compensating for the increased load and preventing image abnormalities
Data Source
AI summary
A touch display device can include a controller configured to output a synchronization signal having a first level during a display driving interval and having a second level during a touch driving interval; a power output circuit configured to receive the synchronization signal from the controller, in response to receiving the synchronization signal having the first level, set an output value of a high-potential voltage to a first voltage, and in response to receiving the synchronization signal having the second level, set the output value of the high-potential voltage to a second voltage that is lower than the first voltage; and a data driving circuit configured to receive image data from the controller, and output data voltages according to the image data by using the high-potential voltage received from the power output circuit to power the data driving circuit.