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Abstract | I. Business Opportunity | II. Current Technology | III. Technology Requirements | IV. References AbstractRefreshable Braille displays present only limited amounts of text at any one time and cannot present graphics at all. The current technology used in these displays are far from optimal due to high cost, problematic maintenance, limited display areas, fragility, and poor heat dissipation. Immediate access to graphics is not available using the current methods of tactile display. The inequality of access to text and graphics puts millions of Americans with visual impairments at a distinct disadvantage in education and employment environments. People with visual impairments require a refreshable Braille display that has the ability to display a full page of tactile text and graphic information. This is not a trivial problem; a significant business opportunity exits for refreshable Braille and tactile graphics display that would allow people with visual impairments to attain true literacy in both textual and graphical information. [ Top of Page ] Business OpportunityPeople who cannot read have great difficulty succeeding in the workplace, in schools, and in the community. Literacy is more influential and important now than it has been at any other stage in the past. However, many people who are blind and visually impaired cannot effectively navigate and scan through textual information with a refreshable Braille display. The consequences of this inability to access Braille and graphic are becoming more and more damaging to their ability to succeed in their communities. Not only do Braille displays offer a private method for reading text in highly populated environments such as the classroom or office, but they also allow for review of written material during meetings, phone calls, and lectures. Access to printed graphics imbedded in print material is equally important. Current refreshable Braille devices make no provision for graphical information. Tables and charts are improperly displayed and non-textual materials such as maps and graphs are not displayed at all. Tabular text is accessed one cell at a time making it difficult to maintain context. An effective refreshable Braille and graphic display device must have the ability to interpret and display graphics in a way that is meaningful to the user. It must also provide an interface that the user can easily understand and manipulate without the benefit of vision. For too long, people with visual impairments have been limited to a mere text description of information presented graphically. Unfortunately, these text descriptions are not capable of providing sufficient understanding of information presented graphically. The ability to access, interact with, and understand graphical interfaces and information is essential to equal access to information in classrooms and workplace environments. Braille literacy is becoming a growing concern in American schools. According to the National Braille Press (2002) Braille is the only medium for true literacy for people with profound vision loss. In the United States today, it is estimated that only ten percent of blind children are taught to read Braille (Jaquiss, 2003). Currently enacted and proposed legislation, such as IDEA '97 (PL 105-17), state Braille literacy bills, and the proposed bill entitled Improving Educational Results for Children with Disabilities (HR 1350) are creating an environment in which Braille literacy will become the norm in American Schools rather than the exception. The addition of a mixed graphic and textual display would allow students who are blind and visually impaired to access the graphics needed to participate in advanced math and science programs that have previously proven difficult or impossible. Computers are becoming an important learning tool in American schools. Each year they are incorporated into lesson plans to a greater extent. Improved access to computers and ubiquitous graphical user interfaces (GUI) would profoundly benefit people with visual impairments. Graphical user interfaces, which are program interfaces that use graphics such as icons and menus to make computers easier to use, would enable individuals to efficiently extract graphical features, triage through graphical images, and control navigations through menus, data, and graphical objects. It is estimated that approximately 448,000 children with vision impairment would benefit from access to Braille, graphics, and computers (Adams, Hendershot and Marano, 1999). They would also be granted access to maps and other graphical data vital to geography, history, and related classes. Today, the number and variety of jobs open to people with visual impairment has risen due to the availability of screen reading software and other assistive technologies, yet the unemployment rate for the working-age blind adults is still high. Braille literacy and computer access are important components in successful employment for people with visual impairments. In fact, there is a significant difference in the unemployment rate of visually impaired people who are able to read Braille (6%) and those that cannot (75%) read Braille (Linn, 2003). Part of the reason for this phenomenon may be the increased speed of access to information that can be obtained with Braille as opposed to the audio output of information. The difficulty associated with using computers and accessing graphics is also reflected in the difference of numbers of individuals with low vision and blindness who use computers when compared with users without vision impairment. In the year 2000, over 50% of individuals without vision impairment and only 13% of users with a vision impairment used computers on a daily basis (U.S. Department of Commerce, Economics and Statistics Administration, and the National Telecommunications and Information Administration, 2000). Access to computers and graphical information would serve to increase the employability of people who are visually impaired in high tech environments. Internet accessibility has become a growing area of concern as it has become one of the largest sources of information for individuals of all ages around the world. Access and use of the internet is lower for individuals with vision impairment than those without. In fact, the majority of persons with no disabilities (57%) report having internet access (at home or elsewhere) in comparison to only 21% of persons with a vision problem (U.S. Department of Commerce, et al., 2000). Access to computer graphical user interfaces will have a significant impact for individuals who are employed, as well as students of all ages. It will also improve the experiences of people with low vision or blindness who use computers for personal and entertainment purposes. Current costs of Braille display technology (currently upwards of $4000 for a 40-line display) preclude the development of Braille literacy for educational and employment opportunities. A low cost advanced refreshable Braille and graphics display would promote inclusion for a large market of people with blindness across all environments, including education, work, recreation, and social inclusion. Also, it would increase the access to brailled material because the time and cost intensive process associated with printed Braille and tactile graphics would be eliminated. [ Top of Page ] Current TechnologyRefreshable Braille displays generally represent uncontracted or contracted Braille. Displays typically employ a single row of cells up to 80 characters long. Braille cells cost approximately $70 each, leading to the high cost of current devices. 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. The underlying technology used currently for Braille displays is piezoelectric or electromagnetic, both of which are expensive and highly fragile technologies. In the piezoelectric display, each pin is located above a piezoelectric crystal with a small piece of metal attached to one side. When no voltage is present, the pin is absent from the display. However, when approximately 200V are applied to the crystal, it shortens resulting in a bowing of the metal (Weber, 1994). As the metal bows, the pin is raised, creating a dot of Braille (TechTarget, 2003). In the electromagnetic Braille display, each pin is enclosed within a casing of no more than 3mm in diameter that also contains a spring and a coil (Weber, 1994). The coil surrounds an iron rod that passes through the casing, forming a miniature solenoid. When a current passes through the coil, the pin is forced inward removing the dot of Braille. If no current is present, the pin is raised, and the dot is present on the display to be read (TechTarget, 2003). Refreshable Braille displays provide dynamic navigation control which allows the user to jump to the end of a line. The navigation controls also allow users to move through a document with curser control. With the exception of the Rotating Wheel-Based Refreshable Display (National Institute of Standards and Technology, 2003), which only allows one to pause in the middle of a document, current refreshable Braille displays lack navigational tools that would allow the user to view a certain page of information. Automated scroll is not seen as an effective solution to enhance navigation and it is currently not available on any of the refreshable Braille displays. Mechanical scroll is featured on many devices and is seen by some as superior to automated scroll. This scroll feature is difficult for people with physical disabilities or reduced sensation in the fingertips to use effectively. Refreshable Braille displays are limited by an inherent weakness of Braille itself, which requires users to learn different codes for different languages thereby making it difficult to switch easily between languages. Currently, refreshable Braille displays are highly complex, with many mechanical components. Even portable devices are large and heavy. For example, a 40-cell display from one manufacturer is 4.8 inches x 12.5 inches x 1.53 inches and weighs 2 lb, 3 oz. Another group sells a mobile device that is 12.2 x 11.4 x .09 inches and weighs 2 lbs, 14 oz. Pins are fragile and may break easily. Current refreshable Braille displays cost $4000 - $5000 for a 40-cell display area, which is cost prohibitive for many users. In general, Braille displays are difficult and expensive to maintain and are not easily or quickly repaired. Often, Braille displays must be shipped back to the manufacturer for repair. This method of repair results in extended periods of time that the user is without the device. [ Top of Page ] Technology RequirementsThe need for an interface that is capable of supporting both Braille and graphics is significant. The capabilities of these devices will have to be varied in order to meet the needs of individual users. This section outlines a continuum of devices, each with increasing capabilities, and their specific technology requirements. Each will build upon the features of the last to provide additional functionality to the user. In order to begin this process, it is important to first outline the technical specification of the Braille cells that would form the basis of all of these devices. Braille and Graphic cells must be:
Refreshable Braille Display (output only) specific requirements:
Refreshable Graphic Display (output only) specific requirements:
Refreshable Tactile Interface (input and output) specific requirements:
Tactile and Audio User Interface:
Tactile Braille and Graphic Computer specific requirements:
[ Top of Page ] References
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