Touch Sensor Controller Noise Mode Adaptation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Touchscreen devices face challenges in accurately detecting touch inputs due to noise signals from external sources, which existing technologies have not effectively addressed, leading to reduced sensing speed and increased power consumption.
Innovation Solution
A touch sensor controller that operates in both normal and noise modes, using a logic circuit to determine the mode based on noise signal magnitude, and switches between mutual-capacitance and self-capacitance methods for touch input detection, with the ability to utilize noise signals for input detection in noise mode, thereby reducing power consumption and improving sensing speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the transmitter continuously outputs driving signals to sensor lines for touch detection, then touch input detection accuracy is maintained, but power consumption increases and sensing speed decreases due to noise signal interference
Solution Approach 1:
The system dynamically switches between normal mode and noise mode based on detected noise signal magnitude. In normal mode, the transmitter continuously outputs driving signals for accurate touch detection. In noise mode, the transmitter stops outputting driving signals to reduce power consumption, while the logic circuit uses noise signal magnitude and sampler output signs to determine touch inputs. This dynamic adaptation resolves the contradiction between maintaining detection accuracy and reducing power consumption under noisy conditions.
Solution Approach 2:
The system changes operational parameters based on noise conditions. The logic circuit monitors noise signal magnitude and switches the operating mode accordingly. In noise mode, the system changes from using driving signals to using noise signals for detection, and the sampler sampling frequency is adjusted based on noise magnitude. This parameter change allows the system to reduce power consumption while maintaining touch detection capability in noisy environments.
2Measurement precision
If the transmitter continuously outputs driving signals to sensor lines for touch detection, then touch input detection capability is maintained, but sensing speed decreases due to noise signal interference
Solution Approach 1:
The system dynamically adjusts its detection method based on noise conditions. In normal mode, continuous driving signals enable comprehensive touch detection. In noise mode, the system switches to a faster detection method where the logic circuit directly uses noise signal magnitude and sampler output signs to determine touches, eliminating the need for continuous driving signal processing and improving sensing speed.
Solution Approach 2:
In noise mode, the system skips the traditional process of using driving signals and instead directly utilizes noise signals for touch detection. The logic circuit rapidly determines touch inputs by comparing sampler output signs with noise signal magnitude, bypassing the slower continuous scanning process and achieving faster sensing speed.
3Use of energy by moving object
If the transmitter stops outputting driving signals in noisy environments, then power consumption is reduced, but touch input detection accuracy may deteriorate
Solution Approach 1:
The system converts the harmful noise signal into a useful detection resource. Instead of treating noise as interference to be eliminated, the logic circuit uses the noise signal magnitude and sampler output signs to determine touch inputs. This approach allows the system to reduce power consumption by stopping driving signals while maintaining touch detection accuracy by leveraging the available noise signals.
Solution Approach 2:
The sensor lines and sampling circuit serve multiple functions: in normal mode, they detect touches using driving signals; in noise mode, they detect touches using noise signals. This multi-functionality allows the system to adapt to different environmental conditions and maintain detection accuracy while reducing power consumption when appropriate.
4Measurement precision
If the system uses traditional noise filtering methods to remove external noise signals, then touch input detection accuracy is improved, but sensing speed and power consumption are adversely affected
Solution Approach 1:
Instead of filtering out noise signals as traditional methods do, the system converts the harmful noise into a useful detection resource. The logic circuit uses noise signal magnitude and sampler output signs to determine touch inputs, achieving accurate touch detection without the need for complex noise filtering that would slow down sensing.
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 effectively enhances touch input detection speed and reduces power consumption by adapting to noise levels, allowing the touch sensor controller to operate efficiently in noisy environments.
Implementation Method 1
a transmitter configured to output a driving signal to sensor lines of a touch panel
Implementation Method 2
a receiver configured to detect a charge generated in the sensor lines by a touch input to generate an analog signal
Data Source
AI summary
A touch sensor controller may include a transmitter configured to output a driving signal to sensor lines of a touch panel, a charge amplifier configured to generate and output a voltage signal by using a charge generated in the sensor lines, a sampling circuit including a first sampler and a second sampler for detecting the voltage signal, and a logic circuit configured to determine whether the transmitter is operating according to a magnitude of a noise signal included in the voltage signal, and, in response to an operation of the transmitter being interrupted, control one of the first sampler and the second sampler to sample the voltage signal according to a sign of the noise signal.