Refreshable Braille Display Using Magnetic Actuation

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Solution Overview

Problem

Current refreshable Braille displays are limited to single-line text due to the high cost and physical constraints of piezoelectric actuators, which restrict their use in multi-line displays, hindering efficient tactile reading for the visually impaired.

Innovation Solution

A tactile display using a housing with pixel units that incorporate a tactile element, a latch, and an actuator generating a magnetic field to induce rotation of a magnetic element, allowing the tactile element to move between extended and retracted positions, enabling compact and cost-effective multi-line displays.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If piezoelectric actuators are used to raise and lower Braille dots, then the tactile display can be manufactured with reliable actuation, but the cost per pixel unit becomes too high for mass production and multi-line displays

Engineering Contradiction:

Improveactuation reliabilityVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces the piezoelectric mechanical actuation system with a magnetic field-based actuation system. The actuator generates a magnetic field that induces rotation of a magnetic element coupled to the latch, eliminating the need for piezoelectric materials and their associated high manufacturing costs while maintaining reliable tactile element actuation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the actuation mechanism from piezoelectric (electrical-to-mechanical direct conversion) to magnetic field-based (electrical-to-magnetic-to-mechanical conversion). This parameter change in the physical principle enables cost-effective mass production while achieving the same functional outcome of raising and lowering Braille dots.

Inventive Principle:

Principle #35Parameter changes

2Length of moving object

If piezoelectric actuators are made sufficiently long to cause the dot to raise enough for Braille, then the tactile element can be actuated to the required height, but the actuator cannot physically reside under the dot in multi-line displays

Engineering Contradiction:

Improveactuator lengthVSAvoidspace under dot

Core Design Contradiction:

Length of moving objectVSArea of stationary object

Solution Approach 1:

The patent resolves the spatial constraint by changing the actuation approach from direct vertical push (requiring long actuators under each dot) to magnetic field-induced latch rotation. The magnetic field can penetrate through the housing structure, allowing the actuator to be positioned in the housing rather than directly under each tactile element, effectively utilizing three-dimensional space arrangement.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Ease of manufacture

If single-line Braille displays are used due to actuator constraints, then the display can be built with current technology, but reading efficiency is significantly slowed down

Engineering Contradiction:

Improvedisplay constructionVSAvoidreading speed

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The patent enables multi-line displays by segmenting the display into multiple independent lines, each with its own pixel units. The cost-effective actuator design allows multiple lines to be implemented simultaneously, enabling readers to access multiple lines of text at once rather than being limited to single-line sequential reading, thereby significantly improving reading efficiency.

Inventive Principle:

Principle #1Segmentation

4Quantity of substance

If multiple actuators are used for each dot in multi-line displays, then complete Braille content can be displayed across multiple lines, but the number of parts and costs per pixel unit increase significantly

Engineering Contradiction:

Improvenumber of Braille linesVSAvoidnumber of parts

Core Design Contradiction:

Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent creates a universal pixel unit design that can be replicated across multiple lines without increasing complexity. Each pixel unit contains the same components (tactile element, latch, magnetic actuator) that can independently perform the same function in any line position, enabling scalable multi-line displays with consistent per-unit costs and simplified manufacturing.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

The solution enables the creation of cost-effective, multi-line tactile displays that can reproduce content dynamically, enhancing reading efficiency for the visually impaired by reducing the number of parts and costs per pixel unit, allowing for larger displays and potential applications beyond Braille.

Implementation Method 1

an actuator coupled to the housing and configured to generate a magnetic field to induce rotation of a magnetic element coupled to the latch

Methodology Applied

Scientific EffectMagnetic field generation: Electromagnet

Data Source

PatentUS11574559B2Refreshable tactile display

Publication Date: 2023.02.07 BEACON STREET INNOVATIONS LLC

AI summary

A tactile display for dynamically reproducing content from an electronic device, such as a computer, tablet, mobile phone or other device, in a touch-sensory format, such as Braille. The tactile display includes a housing and a plurality of tactile elements. The tactile elements are movable relative to the housing between an extended position for engagement by a user and a retracted position at or inward of a surface of the housing.