Autostereoscopic Display Touch Interference Mitigation

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Solution Overview

Problem

Autostereoscopic display devices with touch sensing mechanisms face interference from transient alternating electric fields due to rapid voltage shifts, leading to touch misjudgments and malfunction in the capacitive touch panel.

Innovation Solution

Incorporating a 2D/3D switching panel between the display and touch sensing panels, with a control unit that gradually shifts the first control signal between high and low voltages, and optionally adjusts the second control signal in a similar or opposite phase, to minimize transient electric fields and ensure reliable touch event detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the first control signal is switched from a first low voltage to a first high voltage in a rapid-shift manner, then the response speed of the 2D/3D switching panel is improved, but the sensing operation of the capacitive touch panel is seriously interfered by transient alternating electric field

Engineering Contradiction:
Improveresponse speed of 2D/3D switching panelVSAvoidtouch sensing accuracy
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent applies periodic action by implementing a multi-stage voltage switching scheme where the first control signal transitions through intermediate voltage levels (first intermediate voltage and second intermediate voltage) between low and high states. This periodic, staged approach replaces direct rapid switching, thereby maintaining response speed while eliminating the harmful transient alternating electric field that causes touch misjudgment events.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent implements beforehand cushioning by introducing intermediate voltage levels that act as buffer states during the voltage transition of the first control signal. These intermediate levels cushion the abrupt voltage change, preventing the generation of strong transient alternating electric fields that would otherwise interfere with the capacitive touch panel's sensing operation before the full voltage switch is completed.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Power

If the first high voltage is much higher than the first low voltage, then the voltage swing range is increased for better display performance, but the transient alternating electric field strongly interferes with the capacitive touch panel operation

Engineering Contradiction:
Improvevoltage swing rangeVSAvoidtransient alternating electric field interference
Core Design Contradiction:
PowerVSObject-affected harmful factors

Solution Approach 1:

The patent applies segmentation by dividing the large voltage swing from low to high into multiple smaller stages through intermediate voltage levels. The first control signal transitions sequentially through first intermediate voltage and second intermediate voltage, breaking down the single large voltage jump into several smaller steps. This maintains the necessary voltage swing range for display performance while eliminating the harmful transient electric field generated by abrupt voltage changes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements parameter changes by dynamically adjusting the voltage level of the first control signal through multiple discrete stages rather than a single abrupt change. The control signal parameter (voltage level) is modified incrementally through intermediate states, which changes the temporal profile of voltage application and eliminates the conditions that generate harmful transient alternating electric fields while preserving the full voltage swing range.

Inventive Principle:
Principle #35Parameter changes

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 reduces interference from transient electric fields, enhancing the reliability of touch event detection and preventing malfunctions in the touch sensing mechanism, while maintaining effective 3D image separation for the autostereoscopic display.

Implementation Method 1

The capacitive touch panel typically includes sensing capacitors, and performs signal processing on capacitance variations of the sensing capacitors corresponding to touch points for locating touch input positions

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

The image separation panel has a substrate, a counter substrate, a liquid crystal layer sandwiched between two said substrates

Methodology Applied
Scientific EffectLiquid crystal effect: Liquid Crystals

Data Source

PatentUS8791919B2Autostereoscopic display device having touch sensing mechanism and driving method thereof
Publication Date: 2014.07.29 AU OPTRONICS CORP
  • US8791919B2 patent drawing
  • US8791919B2 patent drawing
  • US8791919B2 patent drawing

AI summary

An autostereoscopic display device having touch sensing mechanism includes a display panel for illustrating images, a touch sensing panel for detecting touch events, a 2D/3D switching panel disposed between the display panel and the touch sensing panel, and a control unit. The 2D/3D switching panel has a substrate, a first electrode disposed on the substrate, a counter substrate, and a second electrode disposed on the counter substrate. The control unit is employed to provide a first control signal and a second control signal furnished to the first electrode and the second electrode respectively. The first control signal is switched between a first high voltage and a first low voltage in a gradual-shift manner. The second control signal is switched between a second high voltage and a second low voltage in a gradual-shift or rapid-shift manner.