Electro magnetic refreshable braille reader
In certain embodiments devices suitable for use as electro magnetic refreshable braille readers are disclosed. In some embodiments, the electromagnetic refreshable braille readers of the present disclosure include an actuation mechanism comprising a permanent magnet for latching and a coil adjacent to the magnet. In some embodiments the electromagnetic refreshable braille readers may comprise a separate enclosure comprising tactile elements that can be removably attached to the display so that the separate enclosure can be removed and cleaned by the user.
1 . A tactile display comprising:
a removable top dot capture assembly comprising a top plate having a plurality of top openings and a bottom plate having a plurality of bottom openings aligned with the top openings, the removable top dot capture assembly containing a plurality of Braille dots, each Braille dot having a mechanical constraint collar formed between an upper Braille portion extending through corresponding top openings in the removable top dot capture assembly when the Braille dot is in a raised position and a lower linkage portion extending through the corresponding bottom openings in the removable top dot capture assembly, where the mechanical constraint collar is configured to limit travel of the Braille dots through the top openings and the bottom openings;
an actuator dot capture assembly disposed beneath the removable top dot capture assembly, where the actuator dot capture assembly contains a plurality of actuator dots aligned with corresponding Braille dots in the removable top dot capture assembly;
an actuator assembly comprising a top stator plate with openings to a plurality of spaces that contain a plurality of magnet actuators, where the actuator dot capture assembly is mounted on top of the actuator assembly to align the plurality of Braille dots and the plurality of actuator dots with the corresponding magnet actuators, the plurality of magnet actuators configured to actuate corresponding Braille dots via the actuator dots, where the magnet actuators are controlled by circuitry on a dot driver board housed within the actuator assembly; and
a membrane between the removable top dot capture assembly and the actuator dot capture assembly, where the membrane is configured to be impermeable to debris and extends across the removable top dot capture assembly between the Braille dots and the corresponding actuator dots.
2 . The tactile display of claim 1 where each of the plurality of magnet actuators includes a magnet disposed within an insulator space and surrounded by a wire coil that, when energized by applying current to the wire coil with the circuitry on the dot driver board, generates a magnetic field that moves the magnet corresponding to the energized wire coil to move the corresponding Braille dot to an up or down position.
3 . The tactile display of claim 2 where the current applied to each wire coil is applied using pulse width modulation.
4 . The tactile display of claim 2 where each wire coil is configured to induce an electromagnetic force that slows the travel of the corresponding magnet as the magnet approaches an impact surface.
5 . The tactile display of claim 4 where each wire coil includes a greater number of windings near an end of the coil to induce the electromagnetic force.
6 . The tactile display of claim 2 where the magnet corresponding to each of the plurality of magnet actuators each move between the top stator plate and a bottom stator when the wire coil surrounding the magnet is energized.
7 . The tactile display of claim 6 where the current applied to each wire coil is applied by calibrating a polarity reversal of the applied current to hold the corresponding magnet against an impact surface disposed on the top stator plate or the bottom stator.
8 . The tactile display of claim 6 where the current to the wire coil surrounding the magnet is controlled to reduce a bounce of the magnet off the top stator plate and the bottom stator.