Optically Clear Keyboard Overlay for Touch Displays

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Solution Overview

Problem

Touch-sensitive devices face challenges in providing precise tactile feedback, leading to incorrect key selection and increased cognitive processing, as they lack the initial spatio-tactile feeling of physical keys, and existing solutions either obscure the display or add bulk and cost.

Innovation Solution

An optically clear keyboard apparatus with button structures made of optically clear material disposed in a fluid, covered by an elastomeric membrane, providing haptic feedback and hysteretic response, which can be applied over a touch-sensitive display screen to offer tactile feedback without obscuring the view.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If soft keys are used on touch-sensitive display screen devices, then device sleekness and screen size are improved, but tactile feedback precision and user input accuracy deteriorate

Engineering Contradiction:
Improvescreen sizeVSAvoidtouch location precision
Core Design Contradiction:
Area of stationary objectVSMeasurement precision

Solution Approach 1:

A transparent overlay with tactile button structures is introduced as an intermediary layer between the user's finger and the touch-sensitive display. This overlay provides physical tactile feedback while allowing the underlying soft keys to remain visible and functional, thus maintaining both large screen size and improved touch precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The overlay incorporates tactile button structures only at specific locations corresponding to virtual keys, while remaining transparent elsewhere. This localized approach provides haptic feedback precisely where needed without obscuring the overall display area, maintaining both screen real estate and input accuracy.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If hardware buttons are used to provide tactile feedback, then user input accuracy is improved, but device bulk and manufacturing cost increase

Engineering Contradiction:
Improvekey selection accuracyVSAvoidhardware component count
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Instead of integrating complex mechanical hardware buttons into the device, a separate transparent overlay with simple tactile structures is used. This intermediary approach provides the necessary tactile feedback while keeping the main device structure simple and reducing manufacturing complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The overlay is constructed as a thin, flexible membrane with raised tactile features that can be easily manufactured and applied. This approach avoids the need for bulky mechanical button assemblies while still providing discernible tactile feedback for accurate key selection.

Inventive Principle:
Principle #30Flexible shells and thin films

3Ease of operation

If existing tactile overlay solutions are used, then tactile feedback is provided, but display visibility is obscured

Engineering Contradiction:
Improvetactile feedbackVSAvoiddisplay visibility
Core Design Contradiction:
Ease of operationVSIllumination intensity

Solution Approach 1:

The overlay utilizes optical properties including transparency and refraction index matching to remain visually imperceptible. The material composition and thickness are designed to minimize light interference, allowing the display to remain fully visible while still providing tactile feedback through the overlay's raised structures.

Inventive Principle:
Principle #32Color changes

Solution Approach 2:

The overlay provides tactile feedback only at specific button locations while maintaining transparency across the entire surface. This localized tactile enhancement approach ensures that display visibility is preserved in areas where tactile feedback is not needed, while still providing physical feedback at key locations.

Inventive Principle:
Principle #3Local quality

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 solution allows for a large display screen with minimal hardware buttons, providing both the benefits of touch screens and hardware buttons, enhancing user input accuracy and reducing cognitive load while maintaining a clear display.

Implementation Method 1

providing haptic feedback

Methodology Applied
Scientific EffectTactile feedback:

Implementation Method 2

providing haptic feedback and hysteretic response

Methodology Applied
Scientific EffectHysteresis: Hysteresis

Implementation Method 3

button structures made of an optically clear material disposed in a fluid... both the buttons and the fluid have a same or substantially the same index of refraction

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP2449447B1Tactile feedback display screen overlay
Publication Date: 2016.07.06 MICROSOFT TECHNOLOGY LICENSING LLC
  • EP2449447B1 patent drawingFigure 1A~2
  • EP2449447B1 patent drawingFigure 3A~3C
  • EP2449447B1 patent drawingFigure 4~5

AI summary

Systems are disclosed for an optically clear keyboard that can be applied to a touch-sensitive display screen, for example, while mitigating distortion of the display. An apparatus for use over a touch-sensitive display screen can comprise a plurality of button structures formed of an optically clear material. The buttons are disposed in an optically clear fluid or gel having an index of refraction equivalent to the index of refraction of the button structures. The apparatus comprises an optically clear elastomeric membrane over the fluid, which forms a sealed barrier for the fluid or gel. The volume within the sealed portion of the apparatus contains the fluid and the button structures.