Touch Screen Controller Dynamic Voltage Scaling
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Solution Overview
Problem
Existing touch screen technologies face challenges in efficiently managing power consumption while maintaining adequate detection resolution, particularly in situations requiring varying levels of precision for point of contact location determination.
Innovation Solution
A novel touch screen controller circuit that drives the touch screen with selectable voltages or currents, allowing the analog-to-digital converter to operate within a convertible input voltage range, reducing power consumption in low resolution situations and increasing resolution when needed by using higher voltages or currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If higher voltage or current is used to drive the touch screen, then measurement precision is improved, but energy consumption increases
Solution Approach 1:
The patent implements dynamic voltage scaling by providing multiple voltage levels (first voltage level for high resolution, second voltage level for low resolution) that can be selectively applied to the touch screen based on detection needs. The controller dynamically switches between voltage levels to match the required precision, avoiding continuous high power consumption while maintaining the capability for high-resolution detection when necessary.
Solution Approach 2:
The patent changes the electrical parameters (voltage level, current level) of the touch screen driver based on the required detection resolution. By adjusting these parameters dynamically - using higher voltage/current for high resolution mode and lower voltage/current for low resolution mode - the system optimizes the trade-off between measurement precision and energy consumption.
2Use of energy by moving object
If lower voltage or current is used to drive the touch screen, then energy consumption is reduced, but measurement precision deteriorates
Solution Approach 1:
The system dynamically adapts the voltage level applied to the touch screen based on the current detection requirements. When low resolution is sufficient (e.g., for basic touch detection), the system operates at the second (lower) voltage level to minimize power consumption. When high resolution is needed (e.g., for precise coordinate determination), the system switches to the first (higher) voltage level, ensuring adequate measurement precision only when required.
Solution Approach 2:
The patent implements parameter changes by selectively applying different voltage levels to the touch screen. The controller monitors or determines the required detection precision and adjusts the electrical parameters accordingly - using the second voltage level for power savings when high precision is not needed, and switching to the first voltage level when measurement precision becomes critical.
3Measurement precision
If fixed high resolution mode is used, then measurement precision is maintained, but energy consumption increases continuously
Solution Approach 1:
The patent transforms the static high-resolution mode into a dynamic system that adapts its operation based on actual needs. The controller can switch between at least two operational states: a high-resolution mode using the first voltage level when precision is required, and a low-resolution mode using the second voltage level when power conservation is prioritized. This dynamic adaptation eliminates continuous high power consumption while maintaining high measurement precision capability when needed.
Solution Approach 2:
The system implements parameter changes by providing multiple operational modes with different voltage levels. Instead of being fixed at high resolution, the touch screen controller can adjust its operating parameters - switching between high voltage/high resolution mode and low voltage/low resolution mode - allowing the system to optimize the balance between measurement precision and energy consumption based on real-time requirements.
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 approach effectively reduces power consumption during low resolution touch screen detection while enabling higher resolution measurements when required, optimizing power usage based on the specific detection needs.
Implementation Method 1
The upper sheet 2 forms a resistive voltage divider with the point of contact being a tap on the voltage divider. There is no current flow through lower sheet 3 due to YM_LL being open and due to sensor 8 being a high input sensor. The voltage sensed by sensor 8 is therefore the voltage on the tap of the voltage divider.
Data Source
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Figure 7~9
AI summary
While taking X-Y coordinate measurements to determine the location of a point of contact on a touch screen, a controller circuit drives the touch screen with a selectable voltage. Voltages output from the touch screen are converted by an ADC into the X-coordinate and Y-coordinate values. The ADC has a convertible input voltage range. If only a low touch screen detection resolution is required, then the voltage with which the touch screen is driven is made to be substantially less than the convertible input voltage range. Only a portion of the convertible input range is usable, but this is adequate for the application and power consumption is reduced. If a higher touch screen detection resolution is required, then the touch screen is driven with a higher voltage. Power consumption is increased, but more or all of the convertible input voltage range of the ADC is then usable.