Sensor Controller Cancels Ground Potential Shifts for Stylus Detection
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Solution Overview
Problem
The existing sensor controller systems face challenges in detecting uplink signals by styluses due to changes in ground potential caused by the uplink signal, leading to failed detections and interference with other apparatuses like display devices.
Innovation Solution
A sensor controller is designed to transmit a predetermined alternating current (AC) signal and a cancellation signal, which is a reverse phase of the AC signal, to prevent the uplink signal from affecting the ground potential of the stylus and other apparatuses, ensuring accurate signal detection and operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the uplink signal transmission power is increased to improve detection sensitivity, then the detection range is extended, but the ground potential of the stylus changes more significantly causing detection failure
Solution Approach 1:
The patent applies preliminary anti-action by introducing a cancellation signal that has the opposite phase to the uplink signal. This cancellation signal is transmitted simultaneously with the uplink signal to preemptively counteract the potential change caused by the uplink signal. The cancellation signal generates an equal but opposite potential change in the ground terminal, thereby nullifying the net potential change and preventing detection failure.
Solution Approach 2:
The patent uses a cancellation signal as an intermediary element to mediate between the uplink signal transmission and the ground potential stability. This intermediary signal acts as a buffer that absorbs the harmful effect of the uplink signal's potential change, allowing the uplink signal to be transmitted at higher power without affecting ground potential stability.
2Speed
If the transmission power of the uplink signal is increased to detect the stylus from a distance, then the detection range is extended, but the interference with other apparatuses such as display devices increases
Solution Approach 1:
The cancellation signal serves as an intermediary that counteracts the interference caused by the uplink signal to other apparatuses. By transmitting the cancellation signal simultaneously, the patent neutralizes the electromagnetic interference that would otherwise affect display devices and other components near the panel surface.
Solution Approach 2:
The patent converts the harmful interference effect of the uplink signal into a beneficial cancellation effect. The same signal that causes interference is used in reverse phase to create a cancellation signal that actively neutralizes the interference, transforming a harmful effect into a protective mechanism.
3Loss of time
If the transmission period of the uplink signal is reduced to improve detection speed, then the detection response time is decreased, but the signal strength becomes weaker reducing detection reliability
Solution Approach 1:
By applying preliminary anti-action through the cancellation signal, the patent enables the uplink signal to be transmitted with shorter duration without compromising detection reliability. The cancellation signal compensates for the reduced signal strength, maintaining ground potential stability even when the uplink signal period is reduced, thus allowing faster detection response.
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 prevents the uplink signal from changing the ground potential of the stylus, allowing for reliable detection and reduces interference with display apparatuses and other devices, ensuring stable operation.
Implementation Method 1
The stylus detects the uplink signal through capacitance formed between sensor electrodes arranged on the panel surface and pen tip electrodes provided at the pen tip of the stylus
Implementation Method 2
transmits, from each of cancellation signal transmission electrodes different from the AC signal transmission electrodes, a cancellation signal configured to prevent a signal transmitted from the AC signal transmission electrodes from appearing in a ground terminal of a detection circuit of a stylus
Data Source
AI summary
A sensor controller is provided, to be connected to a sensor electrode group configuring a surface. The sensor controller supplies a determined AC signal to one or more AC signal transmission electrodes that form part of a plurality of sensor electrodes included in the sensor electrode group, and the sensor controller transmits, from cancellation signal transmission electrode(s) different from the AC signal transmission electrodes, a cancellation signal configured to prevent a signal transmitted from the AC signal transmission electrodes from appearing in a ground terminal of a detection circuit of the stylus. The sensor controller thusly configured may facilitate preventing a situation in which the stylus cannot detect an uplink signal and facilitate preventing the uplink signal from affecting the operation of another apparatus such as a display apparatus.