Charge Pump Circuit on FPC for Display Voltage Conversion
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Solution Overview
Problem
In traditional small-sized and medium-sized thin-film transistor liquid crystal display (TFT-LCD) devices, the voltage converting efficiency of the charge pump circuit is limited by indium tin oxide (ITO) resistors, and it struggles to support varying voltage converting ratios efficiently as screen size grows, leading to increased current consumption.
Innovation Solution
A display system is designed with a charge pump circuit disposed on a flexible printed circuit (FPC) externally coupled to the display device, utilizing a control circuit to generate control signals that control the charge pump circuit, allowing for improved voltage converting efficiency by minimizing the impact of ITO resistors and reducing the number of control signals needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the charge pump circuit is disposed in the driving circuit of the TFT-LCD device, then it can be integrated with the display device, but its voltage converting efficiency deteriorates due to being limited by the indium tin oxide (ITO) resistors
Solution Approach 1:
The charge pump circuit is separated from the driving circuit and disposed on an external FPC substrate. This segmentation removes the charge pump circuit from the ITO resistor-limited environment of the display device, thereby improving voltage converting efficiency while maintaining functional integration through external coupling.
Solution Approach 2:
An FPC substrate is introduced as an intermediary carrier for the charge pump circuit. This intermediary allows the charge pump to be externally coupled to the display device, achieving both physical separation from ITO resistors and electrical connection for efficient voltage conversion.
2Adaptability or versatility
If the charge pump circuit supports voltage converting ratios with different multiples to provide desired output voltage, then adaptability improves, but the number of control signals and pins increases
Solution Approach 1:
The charge pump circuit is designed with multi-functionality to support multiple voltage converting ratios (1.5x, 2x, 3x) through a unified circuit architecture. This universal design allows the same circuit to perform different voltage conversion functions by adjusting control signals, rather than requiring separate circuits for each ratio.
Solution Approach 2:
The charge pump circuit employs dynamic switching mechanisms that can adaptively change operating modes based on control signals. This dynamic capability enables the circuit to switch between different voltage converting ratios on-demand, providing versatility without requiring multiple static circuit configurations.
3Area of stationary object
If the screen size of TFT-LCD device grows, then display area increases, but current consumption increases
Solution Approach 1:
The charge pump circuit dynamically adjusts voltage conversion parameters based on display size requirements. By optimizing the voltage converting ratio and timing parameters, the circuit delivers appropriate voltage levels to larger displays while minimizing excessive current consumption that would occur with fixed voltage output.
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
This configuration enhances the voltage converting efficiency of the charge pump circuit, reduces costs by minimizing pin numbers, and supports various voltage converting ratios, addressing the limitations of traditional TFT-LCD devices.
Implementation Method 1
a charge pump is a kind of DC to DC converter that uses capacitors as energy storage elements to create either a higher or lower voltage power source
Data Source
AI summary
A display system includes a display device, a driving circuit, a flexible printed circuit (FPC), a charge pump circuit and a control circuit. The driving circuit is disposed on the display device, for driving the display device. The FPC is externally coupled to the display device. The charge pump circuit is disposed on the FPC, for generating at least an output voltage to the driving circuit. The control circuit is disposed on the display device and coupled to the driving circuit, for generating a plurality of control signals to control the charge pump circuit. The charge pump circuit has a plurality of control ports coupled to the control circuit for receiving the control signals generated from the control circuit, respectively.