Capacitive Touch Control with Dual Scan Rates for Lower Power

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing electronic devices with capacitive touch screens face issues of unnecessary energy consumption due to permanent scanning for touch key activation, limiting user comfort and increasing electrical energy usage.

Innovation Solution

Implementing a dual operating mode for the electronic module, with a low scanning frequency (1-6 Hz) for normal mode displaying time and a higher frequency (30-100 Hz) for activating functions, allowing a simple touch to switch between modes and reducing energy consumption during complex manipulations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the touch screen is permanently activated with high scanning frequency (64Hz), then user comfort during manipulations is improved, but electrical energy consumption increases

Engineering Contradiction:

Improveuser comfortVSAvoidelectrical energy consumption

Core Design Contradiction:

Ease of operationVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by making the scanning frequency adjustable rather than fixed. The system dynamically switches between a first scanning frequency (lower, for normal operation) and a second scanning frequency (higher, for function activation) based on the operational state. This dynamic adjustment allows the system to optimize between user comfort and energy consumption by using high scanning frequency only when necessary for detecting function activation, and low scanning frequency during normal time display to conserve energy.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the scanning frequency parameter based on operational mode. The electronic module is configured to operate at a first scanning frequency during normal operation and switch to a second, higher scanning frequency when a function needs to be activated. This parameter change allows the system to maintain good touch detection performance when needed while reducing energy consumption during normal operation, directly addressing the contradiction between user comfort and energy usage.

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If the touch keys are scanned at high frequency continuously, then touch detection precision is improved, but the microprocessor usage and energy consumption increase

Engineering Contradiction:

Improvetouch detection precisionVSAvoidmicroprocessor energy consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic action by using different scanning frequencies for different operational periods. During normal operation (time display), the system uses a lower scanning frequency to conserve processor resources and energy. When function activation is detected or needed, the system switches to a higher scanning frequency to ensure precise touch detection. This periodic variation in scanning intensity matches the actual needs of different operational states, reducing unnecessary processor usage while maintaining detection precision when required.

Inventive Principle:

Principle #19Periodic action

3Adaptability or versatility

If additional touch keys are added for function activation, then function selection capability is improved, but device complexity increases

Engineering Contradiction:

Improvefunction selection capabilityVSAvoiddevice complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies universality by making the existing touch screen serve multiple functions. The same touch screen used for displaying time also serves as the interface for activating additional functions through specific manipulation patterns (such as pressing at specific locations or using specific gestures). This eliminates the need for separate physical buttons or additional components, allowing the device to expand its functionality without increasing physical complexity. The touch screen becomes a multi-functional interface that handles both information display and control operations.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 enhances user comfort by eliminating the need for pre-activation of touch keys and significantly reduces electrical energy consumption by optimizing scanning frequencies based on the device's operational mode.

Implementation Method 1

at least two contact zones on which the user can press to act on said at least one electronic module

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentEP2989511B1Method for managing operations on an electronic device

Publication Date: 2021.11.10 ETA SA MFG HORLOGERE SUISSE

Figure 1~2
Figure 3

AI summary

The invention concerns an electronic device (1) comprising a case (2) provided with a glass and a bottom, said electronic device comprising at least one electronic module (6) arranged to calculate the current time, execute a plurality of functions and supply information linked to the current time and to these functions to display means (3) arranged under the glass, the electronic device comprising control means (5) comprising at least one contact area (P1) allowing the user to act on said at least one electronic module, said at least one contact area being monitored by the electronic module at a scanning frequency.