Whitepaper
Braille for the New Millennium ®
Written by Peter Duran, Dwain Gipson and Larry Jenkins
Tactile Dynamics, Inc.®

Braille Overview

Printed books are plentiful and affordable, however, Braille books are 
presently scarce and expensive. A reliable, affordable, and universally 
useful electronic Braille book reader has eluded researchers and 
manufacturers for decades.

The Braille problem

Braille books have many inherent annoyances. They take up too much shelf 
space -- often requiring many separate volumes that are heavy and awkward 
to carry. They are difficult to navigate and are impossible to edit or 
update. They are expensive to produce and expensive to ship. Braille also 
has serious format limitations. Full width printed tables may require 
multiple side-by-side pages to preserve the table layout, and header and 
footer data may require extra lines.  Most Braille printer/embossers do not 
have a linear dot layout. Without the hardware or software ability to print 
the dots between characters and rows, there can be no coherent graphics.

The Braille Solution

Do away with hard copy paper and plastic Braille books, replacing them with 
digital books in DAISY format stored on compact disks. Then use a 
multi-line full-page Braille display to read the CD's.

An innovative technology, recently developed and patented by Tactile 
Dynamics, Inc., makes multi-line refreshable Braille displays and tactile 
graphics displays feasible, practical, and affordable. This white paper 
describes the design and production problems related to present Braille 
displays that are overcome with this new technology. Also, the needed 
functionality of multiline and full-page Braille displays is outlined and 
the benefit to blind and print-impaired readers is discussed.

Information Access Methods

Blind readers can access printed or computerized materials when they are 
presented via an audio rendition (recorded human voice or synthesized 
speech) or via a tactile rendition (Brailled text or tactile graphics). 
Both communication methods have unique benefits. Audio output permits a 
blind reader to quickly and simply grasp the content of the material while 
tactile output lets a blind reader scrutinize the layout and form of the 
material. These two ways to read are complementary. A screen reader permits 
a computer user to compose and edit documents with ease. A full-page 
Braille display would permit a PC user to quickly proofread and easily 
study documents with more complex formats.

There is a fundamental difference between these modes of presentation. 
Audio, as a temporal sequence of acoustic events, provides a linear 
presentation of material whereas Braille provides a 2-dimensional format 
for the information. This 2-dimensional aspect of Braille is vital in many 
circumstances. Data is often communicated best via multicolumn tables; 
travel routes are conveyed best via tactile maps; concepts in geometry are 
explained best via tactile diagrams; and so forth.  At the present time 
multi-line Braille can only be done in paper form with all of the inherent 
disadvantages. Graphics are poorly done, if at all, and present day 
40-character Braille displays are expensive and lack tactile graphics.

Educators of the blind recognize the primacy of Braille as a communication 
medium. Blind students with Braille skills perform better than those who 
rely exclusively upon other communication methods. Blind adults with 
Braille skills are often more gainfully employed than those without these 
skills. The Daisy format will support both the audio and printed or tactile 
format if the presentation equipment and software interface exists.

The Need for Multiline Displays

Dr. Gordon Legge and colleagues at the Minnesota Laboratory for Low-vision 
Research located at the University of Minnesota investigate the 
comprehension of material as a function of the amount of material 
presented. Comprehension is low when only a few words are scanned at a 
time. Comprehension dramatically increases as the number of words read as a 
group increases. These results indicate that Braille displayed only a few 
words at a time on a single line display is very difficult to read. Thus, a 
reader with access to longer lines or to multiple lines will have better 
comprehension of material. This is certainly the case when the material 
involves tabulated text or diagrams.

Mr. Dean Blazie, the dean of portable Braille devices, remarked in a talk: 
"I still think that the Holy Grail in blindness is the full-page display. 
Everybody who is designing Braille modules wants to try to make one that 
you can replicate in two dimensions so that you can make a full page." Many 
researchers and engineers have tried to develop and manufacture a full-page 
Braille display. They have pursued various means to construct this type of 
device; However, all attempts to date have failed.

Often, a problem in science or technology is clearly understood, but a 
solution remains out of reach. History is filled with such problems that 
remained intractable for decades and even for centuries. Typically, 
solutions to difficult problems is forthcoming only when a breakthrough in 
another field provides principles or techniques that make the problem 
manageable, and then the solution seems so "obvious and simple". This is 
the case for a multi-line Braille display. A full-page text reader, now in 
development, is made feasible with specialized micro electro-magnetic parts 
and micro assembly techniques. Precision parts can now be micro molded from 
materials that did not exist 10 years ago. Parts similar in size and 
complexity to those needed in a wrist watch, hearing aid, cell phone or 
digital camera can now be manufactured economically and with the precision 
needed for a full-page Braille display.

Braille Quality and Standards

Most Braille readers in the United States own a Braillewriter manufactured 
by Howe Press of the Perkins School for the Blind in Watertown, 
Massachusetts. Braille readers are accustomed to the feel and size of the 
dots and their placement on a page as produced by this venerable 
Braillewriter. A multi-line display should, therefore, present dots that 
feel this way with the dots placed at standard distances. The National 
Library Service (NLS) for the Blind and the Physically Handicapped, a 
division of the Library of Congress, promotes a national Braille standard 
and recommends that Braille device manufacturers follow this standard as 
closely as possible. Braille text can conform to the exact dot diameter and 
height, dot to dot spacing, cell to cell quarter inch spacing and row to 
row spacing as prescribed by the NLS specification. However, the standard 
Braille dot size and placements do not conform to a linear standard that 
will support tactile graphics.

A minor adjustment to the Braille cell distance measurements (while 
maintaining the dot size and feel) yields a linear resolution of 4 cells 
with 5 dots each per 1.05 inches which can support intermixed Braille text 
and tactile graphics approximating 20 DPI. Without reducing the Perkins 
standard dot size, this approach makes an almost imperceptible adjustment 
of .0125 inch to the cell width.  A 25-line by 40-character full-page text 
only prototype currently under development by Tactile Dynamics that meets 
the Perkins standard will be followed by a graphic unit based on the 20 DPI 
concept. This will be the first ever dual-purpose display to allow the 
intermixing of text and graphics.

Display Size

Refreshable Braille displays have been limited to single line devices with 
only 20, 40 and rarely 80 cells, due to the current complexity and cost of 
Braille technology. The standard embossed Braille page is 40 Braille 
characters wide and 25 Braille lines high, thus, the "Braille area" is 10 
inches by 10 inches. The ideal display would support the full page standard 
or even larger pages. Tactile Dynamics' newly patented technology now makes 
the manufacture of a full-page and even larger tactile displays possible. 
Displays of various sizes are readily achieved and can serve different 
purposes: A full-page display could function as a electronic Braille book 
reader; a multiple line display could function as a portable note taker; a 
very wide display could function as a programmer's input/output terminal; 
and so forth.

The full-page refreshable display under development, based on 
electro-magnetic technology, will be approximately 1 inch taller and 1 inch 
wider than the actual 10-inch by 10-inch Braille area. The perimeter area 
and bottom encasement will provide housing for user controls and internal 
mechanics.

Display Prices

Devices that most people can't afford lack real accessibility no matter 
what access features are included. Prior refreshable displays based on 
mechanical push rods, pneumatics, etc. have been complicated to build, 
expensive to buy and expensive to maintain. Electro-magnetic technology 
permits development and manufacture of full-page displays that users can 
buy for less cost than most of the current single-line displays.

Display Maintenance

Electro-magnetic technology permits the construction of durable Braille 
displays. Reliability, “kidproof” design features, simple maintenance and 
low cost repairs are major considerations governing the design so that 
users can expect hundreds of hours of uninterrupted use. While not a toy, 
the "kidproof" concept is key to being suitable for classroom settings. 
Modular in design, the repair of the new displays by users or by local 
technicians with basic skills and minimal effort will reduce the time users 
are without their units, a crucial factor in educational and vocational 
environments. Tradeoffs between assembly simplicity, maintenance issues, 
manufacturing costs and reliability are primary considerations of the 
Tactile Dynamics displays.

Based on modular structure, the display top assembly is simplified and the 
reliability factor is greatly improved. Most repairs (if needed) will be a 
simple replacement of the disposable Braille cell modules. The membrane 
surface can be readily cleaned of dust, oils from the skin, and even some 
spills or other minor contamination.

Display Power

Multiplexed electro-magnetic technology requires minimal power consumption. 
Data writing is done at relatively low and transient power levels. 
Displayed data is retained mechanically.  The control electronics consume 
very low amounts of power, allowing the full-page display to be operable 
from a USB port without auxiliary power.

Display Refresh

A full-page Braille display that takes too long to refresh would frustrate 
and slow the reader. It is important to refresh a full page quickly. 
Electro-magnetic technology permits a full page to refresh in approximately 
2 seconds.

Display Scroll

Software will allow documents in older formats to be positioned.  The Daisy 
format will allow fast indexing to chapter, page, and paragraph positions. 
In the new full page display, vertical scroll will allow a reader to scan 
up or down while horizontal scroll will allow a reader to move through wide 
tables and spreadsheets. The page dwell time can be adjusted for automatic 
next page refresh or to hold for reading and studying. Control buttons 
along with adjustable rate scrolling of the full page will be valuable 
tools for teaching users to read, speed read, and give feed back to 
software educational programs.

Display Portability

A full-page Braille book reader is anticipated to be an inch larger in 
width and an inch longer than the displayed page. The overall thickness is 
expected to be less than two inches with a total weight under 3 pounds.

Display Controls and Text Formats

The initial models will have Microsoft Windows PC driver support software 
designed to accept text formatted in conventional ways and offering basic 
control functions. Similar to other computer peripherals, an intermix of 
text and escape control codes will allow software products by other vendors 
to be developed for the full-page readers.

Display Care

The active components and exterior surfaces, made from rugged plastic 
polymers, will allow gentle cleaning with regular household products that 
should not be of any particular consequence. Care similar to that given a 
PC will do fine.

Conclusions

At this time the piezoelectric cell is the basic element in most 
refreshable Braille display products. This technology is costly, difficult 
to assemble, and is limited in many ways. An alternative technology, the 
Mechatronic Braille Cell from Robotron, is less expensive and requires less 
power.  The basic module consists of 4 connected Braille cells. This 
technology is still too expensive and requires too many costly 
manufacturing steps.

A simpler, self-contained, larger and lower cost Braille cell module is 
required to reduce assembly time and the cost of Braille display products. 
The first Tactile Dynamics Braille cell modules will be 10 characters wide 
by 5 lines high, (300 dots) permitting the development of various size text 
only displays with fewer assembly modules and fewer assembly steps. A 
replaceable Braille cell module, based on micro-molded magnetic "dot 
elements", will be encapsulated in a thin membrane to protect the cells 
against dust, dirt, spills, and the like. The membrane will conform to a 
dot's shape when a dot is raised and will lie flat when a dot is absent. An 
array of 20 Braille cell modules, 4 wide by 5 high with 6000 dots, mounted 
over a sweeping bar of control electronics forms a full-page text only 
display. Individual dot elements are selectively raised or retracted and 
locked into place as the "electronics bar" passes under a dot row.

Graphics will require a more sophisticated physical layout based on a 20 
DPI system. A single Braille cell module will have 2000 dots in a 10 cell 
by 5 row Braille space. A full page display with 20 Braille cell modules, 
will have 40,000 dots that will accommodate graphics and an intermix of 
text that will still meet the Perkins dot standard.

In either case the Braille cell modules are designed to be replaceable. It 
will be easy to "pop out" one that is damaged and "snap in" a spare 
replacement to make display repairs when necessary. Replacement of the 
disposable Braille cell modules is the basis for a quick and simple 
maintenance strategy. A user, under most conditions, will not have to 
return a display device for depot repair.

The patented engineering for the Tactile Dynamics Braille tablet is based 
on electro-magnetics that eliminate the complex and costly mechanics of 
present day refreshable Braille displays. The underlying electro-magnetic 
technology is not difficult to implement on a larger scale but until 
recently it has not been physically possible to make the small parts needed 
for dynamic Braille. With micro-molding, it is now economically feasible to 
build a full page refreshable display with 6000 dot elements and even the 
40,000 elements needed for graphics.

While the precision made parts are tiny and the electronics are 
sophisticated, it is important to note what the electro-magnetic Braille 
technology does not require. No complicated "latching" mechanisms are used 
to hold the dots in place. No costly crystals are used to represent Braille 
dots. No complicated or expensive electronics are needed to refresh and 
maintain the Braille data. No complicated repairs are required to fix a 
nonfunctional display. In a world already working with 90,000 to 360,000 
color dots per square inch, the Braille resolution is very low and much of 
the software that will first be needed has already been written.

Business Partners

Tactile Dynamics, Inc., intends to complete the development of the Braille 
cell module and its control electronics and then license this technology to 
qualified manufacturers of Braille devices. An initial license fee will be 
required and royalty payments will be based on the products sold which 
incorporate the licensed technology. Manufacturers who help support the 
development of products will be offered priority licenses.

Potential Products

A full-page Braille text only book reader is the target product. Displays 
of other sizes are made possible by forming arrays of the 300 dot Braille 
cell modules.

Displays for intermixed text and graphics will require the 2000 dot Braille 
cell modules.  These displays will permit and encourage the development of 
Braille maps, diagrams, and displayable pictures.

It is exciting to look forward even further to the possibility of laptop 
readers that do not require a separate PC, with truly portable and 
affordable Daisy standard Braille libraries held on a few CD's or flash 
memory cards.

Contact Information

Peter Duran, Director of Sales & Marketing
Tactile Dynamics, Inc.
110 Commerce Drive, Suite 210
Fayetteville, GA  30214
Tel:  770-716-9222
Fax:  770-716-9599
E-mail:  [log in to unmask]


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