Touch Driver IC Sensitivity Switching for Indirect Touch Detection

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Solution Overview

Problem

Conventional touch panels have fixed sensitivity, which can be inadequate when users do not touch the panel directly, such as when their hands are positioned above it, leading to incomplete operations due to insufficient capacitance variation detection.

Innovation Solution

A driver integrated circuit (IC) with a built-in capacitor, reading circuit, and analog-to-digital converter (ADC) that selectively couples the capacitor to the touch panel in parallel or series, adjusting sensitivity based on the number of sensing electrodes detecting a touch event, allowing for dynamic sensitivity adjustment between high and low sensitivity modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the touch panel uses fixed sensitivity arrangement of sensing electrodes, then the manufacturing process is simple, but the sensitivity cannot be adjusted for different touch scenarios

Engineering Contradiction:

Improvesensitivity adjustment capabilityVSAvoiddriver IC structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the capacitor arrangement adjustable rather than fixed. The driver IC can dynamically change the capacitor configuration (connected, disconnected, or partially connected) based on different touch sensing modes, enabling the system to adapt between high sensitivity for indirect touch and normal sensitivity for direct touch scenarios.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the electrical parameter (capacitance) of the touch panel system by selectively connecting or disconnecting capacitors in the driver IC. This parameter change allows the sensitivity to be adjusted without physically changing the sensing electrode arrangement, resolving the contradiction between adaptability and device complexity.

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If the touch panel operates with fixed sensitivity, then the device structure remains simple, but indirect touch detection is insufficient

Engineering Contradiction:

Improvecapacitance variation detectionVSAvoidcapacitor arrangement

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The capacitor arrangement is made dynamic and adjustable. The driver IC can switch between different capacitor configurations (connected, disconnected, or partially connected) depending on the touch sensing mode, enabling high sensitivity detection for indirect touch while maintaining simple operation for direct touch scenarios.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The capacitors are pre-configured in the driver IC and can be quickly switched to the appropriate configuration before or during different touch scenarios. This preliminary preparation allows the system to rapidly adjust sensitivity without complex real-time calculations or physical reconfiguration of the sensing electrodes.

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If the sensing electrodes are arranged for high sensitivity, then indirect touch can be detected, but direct touch may become overly sensitive

Engineering Contradiction:

Improvetouch mode adaptabilityVSAvoidtouch detection accuracy

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The system dynamically adjusts capacitor connectivity based on the detected touch mode. When indirect touch is detected, capacitors are connected to increase sensitivity. When direct touch is detected, capacitors are disconnected or partially connected to reduce sensitivity, preventing overly sensitive responses and maintaining reliable touch detection accuracy across different scenarios.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system uses feedback from the touch sensing results to determine the appropriate capacitor configuration. By monitoring the capacitance variations and identifying whether the touch mode is direct or indirect, the system adjusts the capacitor arrangement accordingly, ensuring reliable and accurate touch detection for each scenario.

Inventive Principle:

Principle #23Feedback

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

Enables effective detection of touch events by dynamically adjusting sensitivity, ensuring reliable operation whether the touch is direct or indirect, enhancing the touch panel's responsiveness and usability.

Implementation Method 1

The driver IC comprises a built-in capacitor, a reading circuit, an analog-to-digital converter (ADC) and a coupling circuit

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS10437365B2Driver integrated circuit of touch panel and associated driving method

Publication Date: 2019.10.08 PIXART IMAGING INC

AI summary

A driver integrated circuit (IC) includes: a built-in capacitor, a reading circuit, an analog-to-digital converter (ADC) and a coupling circuit, wherein the reading circuit receives a sensing signal from a touch panel and outputs an analog sensing data; the ADC is coupled to the reading circuit, and is used to receive and convert the analog sensing data to a digital sensing data; and the coupling circuit is coupled to the reading circuit, and is used to selectively couple the built-in capacitor to the touch panel when the driver IC operates in a touch sensing mode.