Browse Definitions :
Definition

Braille display

Contributor(s): Vipin

A Braille display is a device, typically attachable to a computer keyboard, that allows a blind person to read the contents of a display one text line at a time in the form of a line of Braille characters. Each Braille character consists of six or eight movable pins in a rectangular array. The pins can rise and fall depending on the electrical signals they receive. This simulates the effect of the raised dots of Braille impressed on paper. There are usually 40, 65, or 80 arrays (characters) per line of text, depending on the device. Less expensive devices display fewer characters per line, and require the user to read the standard 80 characters of a normal text line in several readings.

A Braille display operates on either electromagnetic or piezoelectric principles. When currents or voltages are applied to points in each six-pin array, various combinations of elevated and retracted pins produce the effect of raised dots or dot-absences in paper Braille.

In the electromagnetic Braille display, each pin is surrounded by a cylindrical casing that contains a coil. The pin is attached to a spring, and also to an iron rod passing through the casing. This forms a miniature solenoid. When a current passes through the coil, the pin is pulled inward. Thus when there is no current, the pin is elevated, corresponding to a raised dot in Braille; when there is current in the coil, the pin retracts, corresponding to the absence of a dot.

In the piezoelectric display, each pin is mounted above a piezoelectric crystal with metal attached to one side. If a sufficient voltage is applied to the crystal, it becomes slightly shorter. This causes the metal to bow upwards, raising the pin. Thus when there is no voltage, the pin is retracted, corresponding to the absence of a dot in Braille; when there is voltage across the crystal, the pin is elevated, corresponding to a dot.

When used in conjunction with a Braille keyboard, the Braille display makes it possible for a person to operate a computer - read the display, send and receive e-mail, and browse the Web. Other approaches instead of or in addition to the Braille display include voice recognition and speech synthesis technologies.

This was last updated in September 2005

Continue Reading About Braille display

Start the conversation

Send me notifications when other members comment.

Please create a username to comment.

-ADS BY GOOGLE

File Extensions and File Formats

SearchCompliance

  • PCI DSS (Payment Card Industry Data Security Standard)

    The Payment Card Industry Data Security Standard (PCI DSS) is a widely accepted set of policies and procedures intended to ...

  • risk management

    Risk management is the process of identifying, assessing and controlling threats to an organization's capital and earnings.

  • compliance framework

    A compliance framework is a structured set of guidelines that details an organization's processes for maintaining accordance with...

SearchSecurity

  • Trojan horse (computing)

    In computing, a Trojan horse is a program downloaded and installed on a computer that appears harmless, but is, in fact, ...

  • identity theft

    Identity theft, also known as identity fraud, is a crime in which an imposter obtains key pieces of personally identifiable ...

  • DNS over HTTPS (DoH)

    DNS over HTTPS (DoH) is a relatively new protocol that encrypts domain name system traffic by passing DNS queries through a ...

SearchHealthIT

  • telemedicine (telehealth)

    Telemedicine is the remote delivery of healthcare services, such as health assessments or consultations, over the ...

  • Project Nightingale

    Project Nightingale is a controversial partnership between Google and Ascension, the second largest health system in the United ...

  • medical practice management (MPM) software

    Medical practice management (MPM) software is a collection of computerized services used by healthcare professionals and ...

SearchDisasterRecovery

SearchStorage

  • M.2 SSD

    An M.2 SSD is a solid-state drive (SSD) that conforms to a computer industry specification and is used in internally mounted ...

  • kilobyte (KB or Kbyte)

    A kilobyte (KB or Kbyte) is a unit of measurement for computer memory or data storage used by mathematics and computer science ...

  • virtual memory

    Virtual memory is a memory management capability of an operating system (OS) that uses hardware and software to allow a computer ...

Close