A Braille display is a piece of hardware that turns text on a screen into Braille, generally connecting to a computer or cell phone via USB or Bluetooth. The display uses a system of raising and lowering pins in order to create Braille characters. As each braille character can have up to eight dots, every braille “cell” (a space for a single character) must contain eight small pins, and a motor or actuator to raise and lower each one. This means that Braille displays are large, expensive, and generally support displaying a limited number of characters at a time. Today, all Braille displays on the market can only display a single row of text at once, with the characters per row ranging between 16 and 80 characters, depending on the display.
In order to decide what text to display in Braille, a screen reader is generally responsible for controlling the display and outputting text to it. Screen readers can usually output text in speech and Braille at the same time or give the user an option between just Braille or just speech. Until 2018, there was no agreed-upon standard for Braille displays, meaning screen readers had to write custom code to support every single display in the market. However, with the recent USB HID standard for Braille displays, developed by Microsoft, Apple, and others, there is hope that this will soon change, freeing blind users from having to make sure the Braille display they purchase is supported by the screen reader they use.
Another massive improvement in Braille display technology has been in price. The first Braille displays had to be handmade because of the difficulty of making sure all the tiny pins were correctly aligned. This meant that a Braille display could cost as much as ten to $20,000. However, due to recent improvements in manufacturing technology, it is now possible to purchase a Braille display for just under $1,000. While multiline displays have not yet come to market, with the continued drop in price, there is expectation that these may soon be possible, freeing Braille readers from the restriction of a maximum of 80 characters at a time.