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

Braille Overview

Printed books are plentiful and affordable, however, Braille books are=20
presently scarce and expensive. A reliable, affordable, and universally=20
useful electronic Braille book reader has eluded researchers and=20
manufacturers for decades.

The Braille problem

Braille books have many inherent annoyances. They take up too much shelf=20
space -- often requiring many separate volumes that are heavy and awkward=20
to carry. They are difficult to navigate and are impossible to edit or=20
update. They are expensive to produce and expensive to ship. Braille also=20
has serious format limitations. Full width printed tables may require=20
multiple side-by-side pages to preserve the table layout, and header and=20
footer data may require extra lines.  Most Braille printer/embossers do not=
=20
have a linear dot layout. Without the hardware or software ability to print=
=20
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=
=20
digital books in DAISY format stored on compact disks. Then use a=20
multi-line full-page Braille display to read the CD's.

An innovative technology, recently developed and patented by Tactile=20
Dynamics, Inc., makes multi-line refreshable Braille displays and tactile=20
graphics displays feasible, practical, and affordable. This white paper=20
describes the design and production problems related to present Braille=20
displays that are overcome with this new technology. Also, the needed=20
functionality of multiline and full-page Braille displays is outlined and=20
the benefit to blind and print-impaired readers is discussed.

Information Access Methods

Blind readers can access printed or computerized materials when they are=20
presented via an audio rendition (recorded human voice or synthesized=20
speech) or via a tactile rendition (Brailled text or tactile graphics).=20
Both communication methods have unique benefits. Audio output permits a=20
blind reader to quickly and simply grasp the content of the material while=
=20
tactile output lets a blind reader scrutinize the layout and form of the=20
material. These two ways to read are complementary. A screen reader permits=
=20
a computer user to compose and edit documents with ease. A full-page=20
Braille display would permit a PC user to quickly proofread and easily=20
study documents with more complex formats.

There is a fundamental difference between these modes of presentation.=20
Audio, as a temporal sequence of acoustic events, provides a linear=20
presentation of material whereas Braille provides a 2-dimensional format=20
for the information. This 2-dimensional aspect of Braille is vital in many=
=20
circumstances. Data is often communicated best via multicolumn tables;=20
travel routes are conveyed best via tactile maps; concepts in geometry are=
=20
explained best via tactile diagrams; and so forth.  At the present time=20
multi-line Braille can only be done in paper form with all of the inherent=
=20
disadvantages. Graphics are poorly done, if at all, and present day=20
40-character Braille displays are expensive and lack tactile graphics.

Educators of the blind recognize the primacy of Braille as a communication=
=20
medium. Blind students with Braille skills perform better than those who=20
rely exclusively upon other communication methods. Blind adults with=20
Braille skills are often more gainfully employed than those without these=20
skills. The Daisy format will support both the audio and printed or tactile=
=20
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=
=20
Research located at the University of Minnesota investigate the=20
comprehension of material as a function of the amount of material=20
presented. Comprehension is low when only a few words are scanned at a=20
time. Comprehension dramatically increases as the number of words read as a=
=20
group increases. These results indicate that Braille displayed only a few=20
words at a time on a single line display is very difficult to read. Thus, a=
=20
reader with access to longer lines or to multiple lines will have better=20
comprehension of material. This is certainly the case when the material=20
involves tabulated text or diagrams.

Mr. Dean Blazie, the dean of portable Braille devices, remarked in a talk:=
=20
"I still think that the Holy Grail in blindness is the full-page display.=20
Everybody who is designing Braille modules wants to try to make one that=20
you can replicate in two dimensions so that you can make a full page." Many=
=20
researchers and engineers have tried to develop and manufacture a full-page=
=20
Braille display. They have pursued various means to construct this type of=
=20
device; However, all attempts to date have failed.

Often, a problem in science or technology is clearly understood, but a=20
solution remains out of reach. History is filled with such problems that=20
remained intractable for decades and even for centuries. Typically,=20
solutions to difficult problems is forthcoming only when a breakthrough in=
=20
another field provides principles or techniques that make the problem=20
manageable, and then the solution seems so "obvious and simple". This is=20
the case for a multi-line Braille display. A full-page text reader, now in=
=20
development, is made feasible with specialized micro electro-magnetic parts=
=20
and micro assembly techniques. Precision parts can now be micro molded from=
=20
materials that did not exist 10 years ago. Parts similar in size and=20
complexity to those needed in a wrist watch, hearing aid, cell phone or=20
digital camera can now be manufactured economically and with the precision=
=20
needed for a full-page Braille display.

Braille Quality and Standards

Most Braille readers in the United States own a Braillewriter manufactured=
=20
by Howe Press of the Perkins School for the Blind in Watertown,=20
Massachusetts. Braille readers are accustomed to the feel and size of the=20
dots and their placement on a page as produced by this venerable=20
Braillewriter. A multi-line display should, therefore, present dots that=20
feel this way with the dots placed at standard distances. The National=20
Library Service (NLS) for the Blind and the Physically Handicapped, a=20
division of the Library of Congress, promotes a national Braille standard=20
and recommends that Braille device manufacturers follow this standard as=20
closely as possible. Braille text can conform to the exact dot diameter and=
=20
height, dot to dot spacing, cell to cell quarter inch spacing and row to=20
row spacing as prescribed by the NLS specification. However, the standard=20
Braille dot size and placements do not conform to a linear standard that=20
will support tactile graphics.

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

Display Size

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

The full-page refreshable display under development, based on=20
electro-magnetic technology, will be approximately 1 inch taller and 1 inch=
=20
wider than the actual 10-inch by 10-inch Braille area. The perimeter area=20
and bottom encasement will provide housing for user controls and internal=20
mechanics.

Display Prices

Devices that most people can't afford lack real accessibility no matter=20
what access features are included. Prior refreshable displays based on=20
mechanical push rods, pneumatics, etc. have been complicated to build,=20
expensive to buy and expensive to maintain. Electro-magnetic technology=20
permits development and manufacture of full-page displays that users can=20
buy for less cost than most of the current single-line displays.

Display Maintenance

Electro-magnetic technology permits the construction of durable Braille=20
displays. Reliability, =93kidproof=94 design features, simple maintenance=
  and=20
low cost repairs are major considerations governing the design so that=20
users can expect hundreds of hours of uninterrupted use. While not a toy,=20
the "kidproof" concept is key to being suitable for classroom settings.=20
Modular in design, the repair of the new displays by users or by local=20
technicians with basic skills and minimal effort will reduce the time users=
=20
are without their units, a crucial factor in educational and vocational=20
environments. Tradeoffs between assembly simplicity, maintenance issues,=20
manufacturing costs and reliability are primary considerations of the=20
Tactile Dynamics displays.

Based on modular structure, the display top assembly is simplified and the=
=20
reliability factor is greatly improved. Most repairs (if needed) will be a=
=20
simple replacement of the disposable Braille cell modules. The membrane=20
surface can be readily cleaned of dust, oils from the skin, and even some=20
spills or other minor contamination.

Display Power

Multiplexed electro-magnetic technology requires minimal power consumption.=
=20
Data writing is done at relatively low and transient power levels.=20
Displayed data is retained mechanically.  The control electronics consume=20
very low amounts of power, allowing the full-page display to be operable=20
from a USB port without auxiliary power.

Display Refresh

A full-page Braille display that takes too long to refresh would frustrate=
=20
and slow the reader. It is important to refresh a full page quickly.=20
Electro-magnetic technology permits a full page to refresh in approximately=
=20
2 seconds.

Display Scroll

Software will allow documents in older formats to be positioned.  The Daisy=
=20
format will allow fast indexing to chapter, page, and paragraph positions.=
=20
In the new full page display, vertical scroll will allow a reader to scan=20
up or down while horizontal scroll will allow a reader to move through wide=
=20
tables and spreadsheets. The page dwell time can be adjusted for automatic=
=20
next page refresh or to hold for reading and studying. Control buttons=20
along with adjustable rate scrolling of the full page will be valuable=20
tools for teaching users to read, speed read, and give feed back to=20
software educational programs.

Display Portability

A full-page Braille book reader is anticipated to be an inch larger in=20
width and an inch longer than the displayed page. The overall thickness is=
=20
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=20
designed to accept text formatted in conventional ways and offering basic=20
control functions. Similar to other computer peripherals, an intermix of=20
text and escape control codes will allow software products by other vendors=
=20
to be developed for the full-page readers.

Display Care

The active components and exterior surfaces, made from rugged plastic=20
polymers, will allow gentle cleaning with regular household products that=20
should not be of any particular consequence. Care similar to that given a=20
PC will do fine.

Conclusions

At this time the piezoelectric cell is the basic element in most=20
refreshable Braille display products. This technology is costly, difficult=
=20
to assemble, and is limited in many ways. An alternative technology, the=20
Mechatronic Braille Cell from Robotron, is less expensive and requires less=
=20
power.  The basic module consists of 4 connected Braille cells. This=20
technology is still too expensive and requires too many costly=20
manufacturing steps.

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

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

In either case the Braille cell modules are designed to be replaceable. It=
=20
will be easy to "pop out" one that is damaged and "snap in" a spare=20
replacement to make display repairs when necessary. Replacement of the=20
disposable Braille cell modules is the basis for a quick and simple=20
maintenance strategy. A user, under most conditions, will not have to=20
return a display device for depot repair.

The patented engineering for the Tactile Dynamics Braille tablet is based=20
on electro-magnetics that eliminate the complex and costly mechanics of=20
present day refreshable Braille displays. The underlying electro-magnetic=20
technology is not difficult to implement on a larger scale but until=20
recently it has not been physically possible to make the small parts needed=
=20
for dynamic Braille. With micro-molding, it is now economically feasible to=
=20
build a full page refreshable display with 6000 dot elements and even the=20
40,000 elements needed for graphics.

While the precision made parts are tiny and the electronics are=20
sophisticated, it is important to note what the electro-magnetic Braille=20
technology does not require. No complicated "latching" mechanisms are used=
=20
to hold the dots in place. No costly crystals are used to represent Braille=
=20
dots. No complicated or expensive electronics are needed to refresh and=20
maintain the Braille data. No complicated repairs are required to fix a=20
nonfunctional display. In a world already working with 90,000 to 360,000=20
color dots per square inch, the Braille resolution is very low and much of=
=20
the software that will first be needed has already been written.

Business Partners

Tactile Dynamics, Inc., intends to complete the development of the Braille=
=20
cell module and its control electronics and then license this technology to=
=20
qualified manufacturers of Braille devices. An initial license fee will be=
=20
required and royalty payments will be based on the products sold which=20
incorporate the licensed technology. Manufacturers who help support the=20
development of products will be offered priority licenses.

Potential Products

A full-page Braille text only book reader is the target product. Displays=20
of other sizes are made possible by forming arrays of the 300 dot Braille=20
cell modules.

Displays for intermixed text and graphics will require the 2000 dot Braille=
=20
cell modules.  These displays will permit and encourage the development of=
=20
Braille maps, diagrams, and displayable pictures.

It is exciting to look forward even further to the possibility of laptop=20
readers that do not require a separate PC, with truly portable and=20
affordable Daisy standard Braille libraries held on a few CD's or flash=20
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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