Bytes control Braille dots

Bytes control Braille dots.

Prof Pradip K Das started the conversation on a note of reminiscence carrying us to the year 1993 on the day when the first computerised Perkins Brailler (developed at the Computer Science and Engineering Department of Jadavpur University) was installed at the Ramakrishna Mission Blind Boys'Academy at Narendrapur. I was fortunate to be one of the invitees.

About a couple of months ago, when Prof. Das approached us for developing an improved version of the same at theVariable Energy Cyclotron Centre (VECC), Calcutta, I grabbed the opportunity and expressed my willingness to get my team involved in the project. The team members who contributed in the development project include Sunil Das, Sarbajit Pal, Tapas Samanta, Jiban Das,Sunil Karmakar, Ashok Das and  

R B Bhole.

 

The essential components of traditional Perkins Brailler consisted of a movable embossing head split into top and bottom halves having six pins organized in  2x3 rectangular array passing through the bottom half of the head, finally terminating on a coding Shaft. The upper half mirrors the lower half except that the corresponding holes terminate within 0.5mm.

The embossing of any of the combinations of 2x3 array on a thick  special paper in the form of elevated dots constitute Braille character or code devised by Louis Braille in France long ago. The coding Shaft is connected to a row of six coding knobs mounted to the front of the machine in the manner of a first generation typewriter.

Each of the pins is actuated by its corresponding coding Knob. The same row accommodates three more knobs. The one centrally located is meant for shifting the head after every Braille character is embossed like carriage shift in a typewriter. The other two knobs are meant for carriage return and line feed.

The special thick paper on which embossing is to be done makes its way through the split embossing head mounted on the carriage. Pressing the knobs pushes up the selected pins through the bottom half of the head, simultaneously pressing down the top half completing the embossing operation by leaving impressions of the selected Braille character on the paper in a desired form.

After embossing one character, the carriage moves to the next character position and after a line is completed, the next line is started by operating the carriage return and the line feed knobs.

Louis Braille (1809-1852) and English alphabets in Braille code

In the first version of computerised Brailler non-invasive technique was employed which means the original machine was kept intact meaning the original machine was not tampered.

All the keys were operated by pneumatically controlled robot fingers mounted on a common support with each finger accurately positioned above each key. Compressed air from an air compressor, controlled by computer selected electromagnetic valve, actuating the fingers, hammered the keys and completed the embossing cycle.

The system is reliable but robust and noisy and the start up time is high as well . The mass production of such a system is not without substantial investment. 

In the revised version, developed at the VECC, a major modification of the original keyboard was done. Taking advantage of the superior embossing quality of the mechanical Perkins Brailler, the machine has been modified. The coding keyboard has been completely replaced by computer actuated electromechanical links. 

The function of carriage return and line feed have been implemented using accurately controlled action of special motors. The printing speed of the modified Brailler is about 2.5 Braille characters per second. The New system is expected to be installed at Blind Boys Academy, Ramkrishna Mission, Calcutta soon.

One should know the importance of undertaking such a project. Today the mass production of books on different subjects and languages for Blind students is done through Braille Press. It is expensive and, unfortunately, the machine at R K Mission is the only one in the Eastern India. 

Besides English, the Press prints books in languages like Assamese, Oriya, Manipuri, Sanskrit and Bengali. As a result there is a shortage of supply in supply of these books.

"The documents produced using the manual Braille Press caters to only 10 per cent of the demand," says a Maharaj of Blind Boys' Academy. 

The manual Perkins Brailler is much cheaper and thus Blind academies are provided with a few Perkins Brailler. But the process of making a one-page document using such a machine is not only painstaking, error prone and time consuming but also requires special training in Braille coding. 

In the computerised system data in any language can be stored, corrected and finally transferred into appropriate Braille code by Translator Program. This accompanied with error free and uninterrupted service provided by the system increases the throughput by at least 30 times compared to the manual process.

Now that the computerised Braille Press is within our reach, it is going to improve the supply of textbooks to the visually handicapped. Elaborate plans have been chalked out to indegenise the complete system. 

So, days are not very far when we would find Braille farms equipped with a single computer driving a number of Perkins Brailler, each preparing a different document at the same time.

Published in "The Telegraph", Monday, May 13, 1996.