Pixel Capacitor Stacking for Voltage Boosting in Displays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing display devices require high voltage for driving dispersed liquid crystal devices and tandem light-emitting devices, leading to high cost and power consumption in source drivers, and a trade-off between boosting function and aperture ratio or definition.
Innovation Solution
A display apparatus with a pixel circuit that includes a first capacitor and a second capacitor, both electrically connected to a display element, with a structure that allows for increased capacitance value and overlapping regions to enhance the boosting function without compromising the aperture ratio or definition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a boosting function is provided in a pixel circuit to generate voltage higher than the output of a source driver, then the output voltage of the source driver can be reduced, but it is necessary to add components such as a transistor, a capacitor, and a wiring, which increases device complexity and reduces aperture ratio or definition
Solution Approach 1:
The patent merges the boosting capacitor and storage capacitor into a single capacitor structure within the pixel circuit. This consolidation reduces the number of discrete components while maintaining the voltage boosting function, thereby reducing device complexity and increasing aperture ratio compared to using separate boosting and storage capacitors
Solution Approach 2:
The single capacitor in the pixel circuit serves multiple functions: it acts as both the boosting capacitor for generating higher voltage and as the storage capacitor for maintaining the pixel state. This multi-functionality eliminates the need for separate dedicated boosting and storage capacitors, reducing overall component count and circuit complexity
2Power
If a boosting function is provided in a pixel circuit to generate voltage higher than the output of a source driver, then the output voltage of the source driver can be reduced, but it is necessary to add components such as a transistor, a capacitor, and a wiring, which reduces aperture ratio or definition
Solution Approach 1:
The patent merges the boosting capacitor and storage capacitor into a single capacitor structure within the pixel circuit. This consolidation reduces the number of discrete components while maintaining the voltage boosting function, thereby reducing device complexity and increasing aperture ratio compared to using separate boosting and storage capacitors
Solution Approach 2:
The patent utilizes a stacked configuration where conductive layers are arranged in multiple dimensions (horizontal and vertical stacking). This three-dimensional arrangement allows the capacitor to achieve sufficient capacitance value without occupying excessive horizontal pixel area, thereby maintaining high aperture ratio while enabling the boosting function
3Device complexity
If a general pixel circuit is used with a high-output source driver to drive dispersed liquid crystal device and tandem light-emitting device, then the pixel circuit design is simple, but the cost and power consumption of the source driver are high
Solution Approach 1:
The patent implements a dynamic voltage boosting mechanism within the pixel circuit that activates only when needed for dispersed liquid crystal devices or tandem light-emitting devices. This dynamic approach allows the use of a standard source driver for normal operations, reducing its power consumption and complexity requirements, while the pixel-level boosting function engages only when higher voltages are required
Solution Approach 2:
The patent introduces a capacitor-based voltage boosting mechanism as an intermediary between the source driver and the display element. This intermediary structure amplifies the source driver's output voltage locally at the pixel level, allowing a lower-power, simpler source driver to effectively drive high-voltage display elements like dispersed liquid crystal devices and tandem light-emitting devices
Data Source
AI summary
A display apparatus having an excellent boosting function is provided. The display apparatus is provided with a pixel having a function of adding data (a boosting function). A capacitor for boosting voltage is provided in the pixel, and data is added by capacitive coupling to be supplied to a display device. The capacitor for boosting voltage and a capacitor for retaining data are placed on top of each other, whereby the capacitance value of the capacitor for boosting voltage can be increased. Thus, the pixel can have an excellent boosting function, without significantly losing the aperture ratio or definition.