Tactile Overlay for Touchscreen Accessibility

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Solution Overview

Problem

Visually impaired individuals face challenges in operating touchscreens, as they lack the tactile feedback necessary to navigate and select options on self-service devices like ATMs, which are increasingly reliant on touch screens rather than physical keyboards.

Innovation Solution

An auxiliary device with tactile input elements is positioned in front of the touchscreen, allowing visually impaired users to actuate selection fields through haptic feedback, without requiring structural changes to the touchscreen itself. The device includes a non-conductive base element with auxiliary input elements, such as keys or holes, that can be felt and used to select options on the screen, optionally with tactile markings for orientation, and can be easily portable or permanently attached.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a touchscreen is used instead of a physical keyboard, then device modernization and space savings are achieved, but usability for visually impaired persons deteriorates due to lack of tactile feedback

Engineering Contradiction:
Improvedevice modernizationVSAvoidusability for visually impaired persons
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent introduces an auxiliary device as an intermediary between the touchscreen and the visually impaired user. This device includes tactile elements (buttons, markers, raised features) that provide haptic feedback, allowing users to locate and activate touchscreen selection fields without seeing or feeling the screen itself. The auxiliary device mediates the interaction by translating touchscreen coordinates into tactile guidance.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The auxiliary device segments the interaction into two parts: tactile guidance elements (buttons, markers, raised features) and touchscreen activation. Each tactile element corresponds to specific selection fields on the touchscreen, dividing the interface into discrete, locatable regions that can be independently identified and activated through touch.

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If tactile markers are added to assist visually impaired users, then ease of operation improves, but device complexity increases

Engineering Contradiction:
Improveusability for visually impaired personsVSAvoidauxiliary device structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The auxiliary device serves as a separate intermediary component that can be attached to or near the touchscreen without modifying the touchscreen itself. This mediator approach adds tactile complexity only where needed (at the user interface level) while keeping the core touchscreen system simple and unchanged.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The auxiliary device performs multiple functions: providing tactile markers for orientation, raising specific areas to indicate selection fields, and guiding finger placement. By consolidating these functions into a single auxiliary component, the patent avoids distributing complexity across multiple separate modifications.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Illumination intensity

If the auxiliary device is made transparent, then visibility for sighted assistants improves, but manufacturing complexity increases

Engineering Contradiction:
Improvevisibility for sighted assistantsVSAvoidmanufacturing complexity
Core Design Contradiction:
Illumination intensityVSEase of manufacture

Solution Approach 1:

The auxiliary device applies transparency selectively - the base or background portions are transparent to allow sighted users to see through to the touchscreen display, while the tactile elements (buttons, markers, raised features) remain opaque or semi-transparent to maintain their haptic properties. This local differentiation of optical properties allows both visibility and tactile functionality.

Inventive Principle:
Principle #3Local quality

4Reliability

If a non-conductive base element is used, then touchscreen activation is prevented by the base itself, but manufacturing options are reduced

Engineering Contradiction:
Improvetouchscreen activation controlVSAvoidmaterial selection
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The base element is made non-conductive to prevent accidental touchscreen activation, while the tactile elements (buttons, markers) are made conductive to enable intentional activation of selection fields. This local differentiation of electrical conductivity allows the base to block activation while the tactile elements can trigger it when pressed.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2810154B1Aid device for visually impaired persons for operating a touch screen, in particular of an automated teller machine
Publication Date: 2019.03.06 WINCOR NIXDORF INT GMBH
  • EP2810154B1 patent drawingFigure 1

AI summary

The invention relates to an aid device (10, 30) for visually impaired persons for entering information by means of a touch screen (80). The aid device (10, 30) comprises several entry aid elements (14) that can be identified by touching, which are arranged in accordance with the selections fields (90) of a predetermined display (84) of the touch screen (80), which selection fields can be operated by means of a touch, wherein each entry aid element (14) can be uniquely associated with a selection field (90), such that the selection fields (90) can be operated by a visually impaired operator while the aid device (10, 30) is appropriately positioned in front of the touch screen (80).