Braille Display System

Applying the Taylor series expansion to the previous result gives  

By substituting Equation (23.11) into Equation (23.10), an algebraic relation between 0 and 

the trigonometric relationships produce the convex height, h, such as  

How a BraiUe cell operating as per the presented mechanism is fabricated and tested is described in this section. 

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Yobas, L., Durand, D.M., Skebe, G.G., et al. (2003) A Novel Integrable Microvalve for Refreshable Braille Display System, J. Microelectromech. Syst., 12, 252-63. 

A Braille Display System for the Visually Disabled Using a Polymer Based Soft Actuator... 

However, the power of any particular screen reader is in the degree to which the other capabilities dictated by the use of the GUI are achieved. The fundamental differences in the ways that a text-only command-line interface (CLI) and a GUI provide output to the video screen present access problems for persons who are blind. These are related to both the ways in which internal control of the computer display is accomplished and the ways in which the GUI is employed by the computer user (Boyd et al., 1990). The CLI-type interfaces use a memory buffer to store text characters for display. Since all the displayed text can be represented by ASCII code, it is relatively easy to use a software program and to divert text from the screen to a speech synthesizer or Braille display. However, this type of screen reader is unable to provide access to charts, tables, or plots because of their graphic features. This type of system is also limited in the features that can be used with text. For example, features such as size, shape, and font or alternative graphic forms are not captured in standard ASCII text code. 

For those with sight problems the University of Tokyo has developed a thin flexible polymer display where a system of Nafion polymer cantilevers pushes up 0.9 mm radius dots through a 10 pm polydimethylsilane membrane to a height of 0.25 mm above the display surface to form a Braille display. The thin flexible 1 mm thick bendable display is driven by a Braille input. The system is powered at 3 V which is sufficient to cause electro-osmosis which bends the cantilever by differential osmotic pressure. Removal of the voltage allows the cantilever to straighten up and though, theoretically the device can operate at up to 2 Hz, this is not physically possible with the installed organic transistor circuitry. The dots are displayed in a typical 2x3 dot Braille character array - the 4 cm prototype features four rows of six characters. 

Choi, H. R., Lee, S. W., Jung, K. M., et al. (2004) Tactile Display as a Braille Display for the Visually Disabled, Proceedings of the lEEE/RS J International Conference on Intelligent Robotic Systems, Septemher/October 2004, 2, 1985-90. 

This chapter will consider methods and devices used to present visual, auditory, and tactual (touch) information to persons with sensory deficits. Sensory atigmentation systems such as eyeglasses and hearing aids enhance the existing capabilities of a functional human sensory system. Sensory substitution is the use of one human sense to receive information normally received by another sense. Braille and speech synthesizers are examples of systems that substitute touch and hearing, respectively, for information that is normally visual (printed or displayed text). 

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