Universities in four states have agreed to halt schemes to use electronic reading devices until they are fully usable by blind people. The decision concludes a Justice Department investigation over the use of Amazon’s Kindle DX.

The National Federation of the Blind and the American Council of the Blind had sued the universities for violating the Americans with Disabilities Act. The groups complained that using the devices meant blind people were not getting equal opportunities in education.

Although the Kindle DX used in the universities does have a text-to-speech facility, it only applies to the book and magazine content itself. The device’s menu system is visual only, meaning a blind person can’t actually access the text-to-speech tool without assistance.

The affected universities are Case Western (Ohio), Pace (New York), Reed College (Oregon) and Arizona State. Though all four cases involved the Kindle DX, the agreement covers all makes and models of electronic reader.

Assistant attorney general Thomas Perez said “Advancing technology is systematically changing the way universities approach education, but we must be sure that emerging technologies offer individuals with disabilities the same opportunities as other students.”

The agreement doesn’t take effect until the end of this semester. That’s to make sure ongoing projects which use the Kindle can be completed without disruption.

Amazon hasn’t commented on the deal but has previously announced it is working on an audible menu system for future models in the Kindle range. It’s also adding a large print mode to help those with visual impairment.

The voluntary agreement means there’s been no legal ruling on whether the use of such devices without full accessibility features does indeed breach discrimination laws. No damage awards have been made and each party is paying their own legal fees.