DC Transformer Circuit for Low-Cost Negative Display Voltage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The high manufacturing cost and limited availability of DC bulk-boost circuits in existing display technologies make it challenging to develop display devices efficiently, as they are required to generate the necessary negative voltage for display panels.
Innovation Solution
A DC transformer circuit is introduced, comprising a DC transformer module with an energy storing inductor and resistor circuit that transforms input voltage into a negative output voltage, along with an enabling circuit to control the transformation process and prevent malfunctions due to excessive voltage differences, utilizing pulse-width modulation and decoupling capacitors for signal stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a DC bulk-boost circuit is used to generate negative voltage, then the display device can obtain the required negative voltage for switching off thin-film transistors, but the manufacturing cost increases and the availability decreases
Solution Approach 1:
The patent inverts the conventional approach by using a DC buck circuit (typically used for voltage reduction) to generate negative voltage through a transformer module, rather than using a DC bulk-boost circuit (typically used for voltage increase). This inversion allows the use of more available and cost-effective buck circuit designs to achieve the required negative voltage generation function
Solution Approach 2:
The patent changes the operating parameters and configuration of the buck circuit by incorporating a transformer module with specific winding connections and a bulk capacitor connected to the switching node. This parameter change enables the buck circuit to output negative voltage, transforming it from a conventional voltage reduction device into a negative voltage generation device
2Reliability
If a DC bulk-boost circuit is used to generate negative voltage, then the display device can obtain the required negative voltage, but the types of available circuits are limited
Solution Approach 1:
The patent makes the DC buck circuit universal by demonstrating its ability to perform multiple functions: voltage reduction and negative voltage generation. By adding the transformer module and bulk capacitor configuration, the same buck circuit topology can serve both conventional voltage regulation and negative voltage generation needs, increasing design flexibility and availability
3Productivity
If the enabling circuit does not control the voltage difference, then the circuit operates continuously, but malfunctions occur due to excessive voltage differences between input and output
Solution Approach 1:
The patent implements feedback control through the enabling circuit that continuously monitors the voltage difference between input and output. When the voltage difference exceeds a predetermined threshold, the enabling circuit disables the buck circuit, preventing damage from excessive voltage stress. This feedback mechanism ensures reliable operation by adapting the circuit's operational state based on real-time voltage conditions
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 DC transformer circuit effectively generates a negative voltage for display devices at a lower cost compared to traditional DC buck-boost circuits, while preventing malfunctions by controlling the enabling voltage based on input and output voltage values, thus enhancing the development of display devices.
Implementation Method 1
an energy storing inductor, a first end of the energy storing inductor connected to the module output pin and a second end of the energy storing inductor connected to a grounded terminal, configured to be fed with the module output voltage outputted by the module output pin
Implementation Method 2
a decoupling circuit for storing energy to remove signal interference, the decoupling circuit including: a first decoupling capacitor, the first end of the first decoupling capacitor fed with the input voltage and connected to the input pin
Data Source
AI summary
A DC transformer circuit is provided. A first end of an energy storage inductor in the DC transformer circuit is connected with a module output pin in a DC transformer module, and a second end of the energy storage inductor is connected to a grounded terminal. Using the DC transformer circuit can thus generate a negative voltage for a display device. Compared to a DC buck-boost circuit adopted in the existing arts, the DC transformer circuit has an advantage of low cost.