Gate Driving Circuit Back Bias Control for Display Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing display devices face reliability issues with gate driving circuits due to threshold voltage shifts at high temperatures, leading to increased current consumption and potential degradation of transistors.
Innovation Solution
A display device with a gate driving circuit that includes a signal controller to detect current variations and output a back bias control voltage, adjusting the threshold voltage of transistors to minimize consumption current, using a back bias selection portion to provide the control voltage based on the detected current levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the gate driving circuit operates at high temperature, then the display device can maintain normal operation, but the threshold voltage of transistors shifts leading to increased current consumption
Solution Approach 1:
The patent implements a feedback mechanism where the signal controller continuously monitors the current consumption of the gate driving circuit and dynamically adjusts the back bias voltage applied to the transistor back gates. When current consumption exceeds a threshold, the controller modifies the back bias voltage to compensate for threshold voltage shifts, thereby reducing current consumption while maintaining operation at elevated temperatures.
Solution Approach 2:
The patent changes the back bias voltage parameter applied to the transistor back gates in response to temperature-induced threshold voltage shifts. By dynamically adjusting this voltage parameter, the system compensates for thermal effects on transistor characteristics, maintaining optimal current consumption levels across varying operating temperatures.
2Duration of action of stationary object
If the gate driving circuit operates continuously, then the display device maintains functionality, but the transistors degrade over time reducing reliability
Solution Approach 1:
The patent applies preliminary protective action by continuously monitoring current consumption and proactively adjusting back bias voltages before significant transistor degradation occurs. The signal controller detects early signs of threshold voltage shifts and compensates in advance, preventing cumulative damage that would otherwise reduce reliability during continuous operation.
Solution Approach 2:
The feedback mechanism monitors operational parameters in real-time and adjusts back bias voltages to prevent excessive current stress on transistors during continuous operation. This active compensation reduces thermal and electrical stress accumulation, thereby extending the operational lifespan and maintaining reliability over extended periods.
3Use of energy by moving object
If the threshold voltage is adjusted to minimize current consumption, then energy efficiency improves, but the circuit complexity increases due to additional control mechanisms
Solution Approach 1:
The signal controller is designed to perform multiple functions: it generates clock signals for the gate driving circuit, monitors current consumption, determines threshold voltage shifts, and adjusts back bias voltages. By consolidating these diverse functions into a single multi-functional controller, the patent minimizes the addition of separate control circuits, thereby reducing overall system complexity while achieving current consumption optimization.
Solution Approach 2:
The patent merges the current monitoring function, threshold voltage detection function, and back bias control function into an integrated signal controller. This consolidation eliminates the need for separate monitoring circuits and control logic, reducing device complexity while maintaining the capability to dynamically optimize current consumption through back bias adjustment.
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
The solution improves the reliability of the gate driving circuit by maintaining optimal threshold voltages and reducing current consumption, thereby extending the operational lifespan and efficiency of the display device.
Implementation Method 1
each of the plurality of driving stages includes at least one transistor configured to adjust a threshold voltage based on the back bias control voltage
Data Source
AI summary
A display device includes: a display panel; a voltage generator to output a gate on voltage to a voltage output terminal; a clock generator to receive the gate on voltage to generate at least one clock signal; a gate driving circuit including a plurality of driving stages to output gate signals to gate lines in response to the at least one clock signal, each of the driving stages including at least one transistor to adjust a threshold voltage based on a back bias control voltage; and a signal controller to detect a current variation of the voltage output terminal and including a back bias controller to search for the back bias control voltage to minimize a consumption current level of the voltage output terminal while changing the back bias control voltage from a default voltage level when the detected current variation is greater than a reference level.