Touch Driving Circuit for Contact and Hover Sensing
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Solution Overview
Problem
Existing touch display devices struggle to efficiently sense both contact and non-contact (hover) touches, limiting their functionality and versatility.
Innovation Solution
A touch display device with a touch driving circuit and controller that supports multiple touch sensing modes, including a first touch sensing mode for contact touches and a second touch sensing mode for hover touches, using distinct amplitude levels and timing to differentiate between the two, allowing simultaneous or non-overlapping operation of these modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single touch sensing mode is used, then the circuit structure and control system are simple, but the device cannot efficiently sense both contact and hover touches
Solution Approach 1:
The patent implements dynamic switching between two touch sensing modes (contact touch mode and hover touch mode) through a controller that adjusts driving signal parameters. The touch driving circuit dynamically changes the amplitude and timing of driving signals applied to touch electrodes based on the detected touch type, enabling adaptive sensing without permanent structural complexity
Solution Approach 2:
The patent changes key parameters of the driving signal including amplitude (first amplitude for contact touch, second amplitude for hover touch), frequency, and timing to differentiate between contact and hover touch sensing modes. This parameter-based differentiation allows a single circuit structure to support multiple sensing functions
2Measurement precision
If separate sensing periods are used for contact and hover touches, then sensing accuracy is improved, but the sensing time increases
Solution Approach 1:
The patent employs periodic sensing operations where the controller alternates between contact touch sensing periods and hover touch sensing periods. During each frame period, the system performs sensing at different time points with different driving signal characteristics, enabling both sensing modes to operate in a time-division multiplexed manner that maintains accuracy while managing time consumption
Solution Approach 2:
The controller preliminarily determines the touch type (contact or hover) by analyzing initial sensing signals and then adjusts subsequent driving signals accordingly. This preliminary detection allows the system to prepare appropriate sensing parameters in advance, reducing the total sensing time required for accurate measurement
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 efficient sensing of both contact and hover touches, enhancing the device's functionality and versatility while optimizing power consumption.
Implementation Method 1
a touch sensor including a plurality of first touch electrodes and a plurality of second touch electrodes, and a touch driving circuit for driving the touch sensor
Data Source
AI summary
A touch display device and a touch driving circuit are discussed. An operation period of the touch display device can include a first touch sensing mode period in which a first touch driving signal having a first amplitude is applied to the touch sensor, and a second touch sensing mode period in which a second touch driving signal having a second amplitude different from the first amplitude is applied to the touch sensor. The first touch driving signal can be sequentially applied to each of a plurality of first touch electrodes during the first touch sensing mode period, and, during the second touch sensing mode period.