Touchscreen Rotary Input Layout for Flexible Knob Placement

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Solution Overview

Problem

Existing input devices for touchscreen panels are limited in their placement on the front surface and cannot accurately detect rotary operations across the entire surface due to fixed electrode arrangements that overlap with line electrodes, restricting their functionality and placement flexibility.

Innovation Solution

The input device includes a base member with rotatably positioned operating members and strategically arranged fixed electrodes that can switch between conductive and non-conductive states, allowing placement at any location on the touchscreen panel and enabling detection of rotary operations through the use of tangentially aligned electrodes and a moving electrode that alternates conductive states.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If fixed electrodes are arranged to face sensor electrodes in the touchscreen panel, then rotary operations can be detected through electrostatic capacitance variation, but the input device can only be provided within a certain range on the front surface of the touchscreen panel

Engineering Contradiction:
Improvedetection accuracy of rotary operationsVSAvoidplacement flexibility on touchscreen panel
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent transitions from a two-dimensional electrode arrangement (fixed electrodes facing sensor electrodes on the same plane) to a three-dimensional configuration where fixed electrodes are positioned on the front surface and line electrodes extend through multiple layers. This dimensional change allows the input device to be placed at any location on the front surface while maintaining detection capability through the extended line electrode structure that intersects with first line electrodes at multiple points.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent divides the electrode system into separate functional components: fixed electrodes for defining detection zones, first line electrodes for signal transmission, and second line electrodes for detection. This segmentation allows each component to be optimized independently and placed flexibly across the touchscreen surface without requiring direct facing arrangements, thereby enabling placement anywhere on the front surface while maintaining detection accuracy.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If fixed electrodes are arranged to overlap with line electrodes, then the input device structure is simplified, but the detection accuracy of rotary operations deteriorates

Engineering Contradiction:
Improvestructural complexity of electrode arrangementVSAvoiddetection accuracy of rotary operations
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent resolves the conflict between structural simplicity and detection accuracy by extending line electrodes into the third dimension through multiple layers. First line electrodes are arranged to overlap with fixed electrodes on the front surface, simplifying the structure, while second line electrodes are positioned in overlapping regions to maintain detection accuracy. This multi-layer configuration allows both structural simplicity and detection precision to coexist.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent introduces second line electrodes as intermediary elements that mediate between the fixed electrodes and the detection system. These second line electrodes are specifically positioned in overlapping regions with first line electrodes, acting as intermediaries that maintain detection accuracy even when fixed electrodes overlap with line electrodes, thus resolving the contradiction between structural simplicity and detection precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If a moving electrode is used to switch between conductive and non-conductive states, then rotary operations can be detected, but the device complexity increases

Engineering Contradiction:
Improveoperability of rotary input deviceVSAvoidcomplexity of electrode switching mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The moving electrode automatically switches between conductive and non-conductive states based on its rotational position relative to fixed electrodes, without requiring external control mechanisms. This self-service approach enables rotary operation detection while minimizing additional complexity, as the switching action is an inherent result of the mechanical rotation rather than a separately controlled function.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent combines the moving electrode with the operating member (rotary knob) into a single integrated component. The moving electrode is positioned on or with the operating member, merging the detection function with the mechanical interface. This integration reduces overall device complexity by eliminating separate actuation mechanisms while maintaining the ability to detect rotary operations through electrostatic capacitance changes.

Inventive Principle:
Principle #5Merging (Combining)

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 configuration allows the input device to be placed at any location on the touchscreen panel and accurately detects rotary operations, enhancing user interaction and flexibility in device placement without overlapping issues with line electrodes.

Implementation Method 1

This movement causes a variation in electrostatic capacitance produced between the fixed electrodes and the sensor electrodes. When this variation in electrostatic capacitance is detected by the touchscreen panel, the rotary operation on the rotary operating knob is detected by the touchscreen panel.

Methodology Applied
Scientific EffectElectrostatic capacitance: Capacitance

Data Source

PatentEP3982387B1Input device and input system
Publication Date: 2023.09.06 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3982387B1 patent drawingFigure 1
  • EP3982387B1 patent drawingFigure 2
  • EP3982387B1 patent drawingFigure 3

AI summary

Provided is an input device which may be provided at any location on the front surface of a touchscreen panel and which enables the touchscreen panel to detect an operation performed on the input device. An input device includes a contact board, a rotary click cam, and fixed electrodes 252a, 252b. The contact board is placed on a front surface of a touchscreen panel. The rotary click cam is provided rotatably around a rotational axis L3 with respect to the contact board. The fixed electrodes 252a, 252b are arranged on a lower surface of the contact board. The fixed electrodes 252a, 252b are configured to, as the rotary click cam is operated, be switched from an electrically conductive state into an electrically non-conductive state, or vice versa. The fixed electrode 252a includes a first shifted portion P1 shifted by a first predetermined distance R11 with respect to the fixed electrode 252b. The fixed electrode 252b includes a second shifted portion P2 shifted by a second predetermined distance R12 with respect to the fixed electrode 252a.