Tactile graphic computer screen and input tablet for blind persons using an electrorheological fluid

Abstract

A tactile screen for blind users is formed by a board with an array of holes filled with an electrorheological fluid and a membrane fixed on the surface of the board. The holes are equipped with electrodes forming electrically controlled valves which connect or disconnect the cavities under the membrane with the fluid on the back of the board. To set the membrane section over a valve to a certain state, the pressure of the fluid must be set to the desired valve and the valve must be opened. Another possibility is to form by electrodes, a bidirectional pump in each hole. The user is getting the information by immediately touching the membrane or by touching pins lifted by the membrane. By successively switching electrical impulses on all rows and columns of electrodes and evaluating the electrical signal capacitively coupled to the body of the user, the coordinates of the users fingertips are determined. In this way the board is used as an input device.

Dependencies are inferred from the claim text.