Touch Driver Dynamic Frequency Adjustment for Sleep Mode Recognition

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Solution Overview

Problem

Touch screen devices in sleep mode have a low touch recognition rate due to reduced scanning frequencies for power conservation, making it uncomfortable for users to wake them up as they may not sense touches accurately.

Innovation Solution

A method that adjusts touch driving signal frequencies in sleep mode, starting with a higher frequency after normal mode, then lowering to a second and third frequency, with corresponding reference values to detect user input and wake the device, ensuring higher touch recognition rates while minimizing power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the touch screen device operates in sleep mode with reduced scanning frequency to save power, then power consumption is reduced, but touch recognition rate deteriorates

Engineering Contradiction:
Improvepower consumptionVSAvoidtouch recognition rate
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent applies dynamics by making the scanning frequency adjustable rather than fixed. The system dynamically switches between first scanning frequency (higher) and second scanning frequency (lower) based on operational state. During sleep mode, it uses the lower frequency to save power, while maintaining the capability to switch to higher frequency when touch input is detected, thus resolving the contradiction between power consumption and touch recognition rate

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the scanning frequency parameter based on operational conditions. By defining different scanning frequencies for different modes (sleep mode vs. active mode), the system optimizes power consumption during idle periods while ensuring reliable touch recognition when needed. The controller adjusts this parameter dynamically based on whether the device is in sleep mode or receiving user input

Inventive Principle:
Principle #35Parameter changes

2Use of energy by stationary object

If the touch screen device uses low scanning frequency in sleep mode, then power consumption is reduced, but the device cannot sense user touch accurately

Engineering Contradiction:
Improvepower consumptionVSAvoidtouch sensing accuracy
Core Design Contradiction:
Use of energy by stationary objectVSMeasurement precision

Solution Approach 1:

The system dynamically adjusts scanning frequency based on operational state. During sleep mode, it operates at lower frequency to minimize power consumption. When a touch event is detected (even at lower frequency), the system transitions to higher scanning frequency to accurately sense and process the user input, thus resolving the contradiction between power savings and sensing accuracy

Inventive Principle:
Principle #15Dynamics

3Use of energy by moving object

If the touch screen device scans at reduced scanning rate in sleep mode, then power consumption is reduced, but touch detection capability is compromised

Engineering Contradiction:
Improvepower consumptionVSAvoidtouch detection capability
Core Design Contradiction:
Use of energy by moving objectVSDifficulty of detecting and measuring

Solution Approach 1:

The patent implements dynamic frequency adjustment where the scanning rate is not fixed but adapts to operational needs. The controller switches between reduced scanning rate (for power savings in sleep mode) and normal scanning rate (for accurate touch detection). This dynamic approach resolves the contradiction by allowing the system to optimize for power consumption during idle periods while maintaining full detection capability when user interaction occurs

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system performs preliminary touch detection at the reduced scanning rate even in sleep mode. This preliminary action allows the system to detect basic touch events without consuming full power, and only then transitions to higher scanning rate for detailed processing, thus partially resolving the contradiction between power consumption and detection capability

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3037933B1Touch screen device and method for driving the same
Publication Date: 2018.08.29 LG DISPLAY CO LTD
  • EP3037933B1 patent drawingFigure 1
  • EP3037933B1 patent drawingFigure 2
  • EP3037933B1 patent drawingFigure 3

AI summary

A touch driver, a touch sensitive display device and a method for driving the same capable of increasing the touch recognition rate of the touch sensitive display device in the sleep mode are disclosed. The touch sensitive display device supports a normal mode and a sleep mode. The display device includes touch driving lines (C1 to Cp) and the touch driver (50) to supply one or more touch driving signals (TS1 to TSp) to the touch driving lines (C1 to Cp). The touch driver (50) supplies the one or more touch driving signals (TS1 to TSp) at a first frequency during the normal mode of the touch sensitive display device, supplies the one or more touch driving signals (TS 1 to TSp) at a second frequency during a first portion of the sleep mode of the touch sensitive display device, and supplies the one or more touch driving signals (TS1 to TSp) at a third frequency during a second portion of the sleep mode of the touch sensitive display device.