Classifications

• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09B—EDUCATIONAL OR DEMONSTRATION APPLIANCES; APPLIANCES FOR TEACHING, OR COMMUNICATING WITH, THE BLIND, DEAF OR MUTE; MODELS; PLANETARIA; GLOBES; MAPS; DIAGRAMS
  • G09B21/00—Teaching, or communicating with, the blind, deaf or mute
  • G09B21/001—Teaching or communicating with blind persons
  • G09B21/003—Teaching or communicating with blind persons using tactile presentation of the information, e.g. Braille displays
  • G09B21/004—Details of particular tactile cells, e.g. electro-mechanical or mechanical layout

Definitions

• the invention relates to a Braille display, in particular tactile matrix, which is applicable for the creation an auxiliary computer interface for the visually impaired people.
• a Braille computer monitor [1] represents a matrix comprised of a base with vertical holes, through which movable elements - needles with flexible cord are passing. The up and down movement of the needles is carried out by an electromechanical bi-directional motor drive, which raises the needle from beneath and its detention in a position is performed by a flexible cord.
• clusters "engine-needle-cord" are distributed into cells of 8 items - 2 columns with 4 needles each. Any cluster may represent a literal / digital symbol which is perceived by touch by a visually impaired person.
• a disadvantage of the Braille computer monitor is the use of multiple mobile needles with complex start up for the creation of the necessary tactile sensation that seriously raises the cost of the device.
• Another limitation is the lack of a common link between all needles due to the differentiation of each group of 8 needles as a separate symbol.
• a disadvantage is the relatively heavy weight of the needle in the driving system requiring more energy for the start up.
• Last but not least that has to be taken into consideration is the complicated structure, as well as the uncomfortable technology for implementation wherein, adjustment is required because of the mobility of the needles.
• the object of the invention is to provide a Braille display with simple structure and easy conversion technology with improved static, dynamic and energy performance, as well as to apply a common link between all moving parts, an extended tactile feedback and a highly efficient start up with low consumption of energy.
• a Braille display representing a matrix, comprised of a base with fixed electromagnets which are arranged thereon and include an outer cylindrical magnetic core.
• two other magnetic cores are placed - a winding magnetic core, locking up the cylindrical magnetic core at the top side, as well as a winding magnetic core, locking up the cylindrical magnetic core at the bottom side.
• These two magnetic cores that are included are with axial holes and into the space between the windings a movable non-magnetic cylindrical body is placed, that carries a permanent and axially magnetized, cylindrical magnet and a non-magnetic needle, passing axially through the permanent magnet and the axial holes of the magnetic cores.
• a ferromagnetic disc At the top side of the permanent magnet a ferromagnetic disc is arranged, that has an axial hole, and on its underside - a ferromagnetic disc having an axial hole wherein.
• the upper disc and the upper magnetic core have cylindrical poles and the lower magnetic core and the lower disc have conical poles.
• Above the electromagnets a lattice is placed with openings through which the needles pass.
• the electromagnets can be placed in the matrix in one line but also in two, three or more lines, side by side, at an offset along two axes (x and y) and a different length of the movable needles along the third axis (z), and in this way they overlap and occupy less space in the matrix.
• the tips of the needles are in one plane - the plane of the lattice with openings of the Braille display.
• An advantage of the invention is that the retention of the needles in their final positions does not need an external power supply, as it is provided by the permanent magnet.
• One improvement is the lack of additional springs, which allows a very precise control of the feed force for realizing of the tactile feedback connection.
• a further advantage is the intermittent power supply voltage which enables an extremely low power consumption (only for moving the needle from one end to the other), as well as more efficient use of materials and reducing of the size of the matrix.
• An advantage of the present invention are the extremely low electric and mechanical time constants, resulting in very good velocity and dynamic characteristics. Furthermore to be taken into consideration, is the considerably wider range of the realizable tactile feedback due to the fact that all electromagnets can be operated simultaneously and synchronously, which gives the operator a more realistic and closer to reality tactile perception.
• Another advantage is that not only letters and numbers, but also graphic symbols (roots, integrals), images of icons, paintings in the case of larger matrix and others can be written on the tactile (Braille) matrix.
• a positive feature is the extremely high positioning accuracy of the needles and the stability of the retaining forces keeping them into their final positions.
• Another advantage is that the chosen propulsion method is distinguished by its exceptional reliability and trouble-free operation and requires no additional settings and service.
• the technology convenient for the realization of the matrix, is also an advantage.
• Figure 1 represents the location of the electromagnets in the matrix.
• Figure 2 is a cross-sectional view of one element of the matrix.
• the exemplary embodiment of the invention is a Braille display, representing a matrix, comprised of base 1 with stationary mounted electromagnets thereon, which comprises an outer cylindrical magnetic core 2, wherein the coil 3 with magnetic core 4 are placed, the magnetic core 4 locking up the cylindrical magnetic core 2 at the top side, as well as the coil 5 with the magnetic core 6, the core 6 locking up the cylindrical magnetic core 2 from the bottom side.
• the magnetic cores 4 and 6 with the coils 3 and 5 are with axial holes, and within the space between the coils 3 and 5 a movable non-magnetic cylindrical body 7 is placed, that carries a cylindrical axially magnetized permanent magnet 8 and a non-magnetic needle 9, passing axially through the permanent magnet 8 and the axial holes of the magnetic cores 4 and 6.
• a ferromagnetic disc 10 with an axial hole is placed, and on its underside a ferromagnetic disc 1 with an axial hole is placed, wherein the upper disc 10 and the upper magnetic core 4 have cylindrical poles 12 and the lower disc 11 and the lower magnetic core 6 are with conical poles 13 and a lattice is arranged above the electromagnets with openings 14 through which the needles 9 pass.
• the electromagnets can be placed in the matrix in one line, as well as in two, three or more lines at an offset along two axes (x and y) and with a variable length of the movable needles 9 along the third axis (z), such S
• the tips of the needles 9 are coplanar with the plane of the lattice with openings 12 of the Braille display.
• the invention is used in the following manner:
• the nonmagnetic needle 9, rigidly connected to the nonmagnetic body 7, that non-magnetic body 7 carrying the permanent magnet 8 with ferromagnetic discs 10 and 11 is moved upwards until the appropriate ferromagnetic plate 10, which is next to the pole 12 of the magnetic core 4, is reached and it is kept in this top position after the decline of the pulse due to the attractive forces between the permanent magnet 8 and the magnetic core 4, with needle 9 protruding above the lattice 14 with holes of the Braille display.
• the nonmagnetic needle 9 moves downwards until the ferromagnetic disc 11 next to the pole 13 of the magnetic core 6 is reached and remains in that lower position after the decline of the pulse due to the forces of attraction between the permanent magnet 8 and the magnetic core 6, as the needle 9 does not protrude above the lattice 14 with holes of the Braille display.
• All electromagnets are controlled simultaneously and in a synchronized manner, such that to obtain a general image with needles 9 - text or graphic on the entire matrix.
• the visually impaired person feels by touching only those needles 9 that protrude above the lattice 14 with holes of the Braille display, since permanent magnets 8 are in upward position.
• the electromagnets can be placed in the matrix in one line, as well as in two, three or more lines, side by side at an offset along two axes (x and y) and with a different length of the movable needles 9 along the third axis (z), such that they overlap and occupy less space in the matrix, and the tips of needles 9 are coplanar with the plane of the lattice 14 with holes of the Braille display.

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Cited By (4)

Citations (3)

• 2013
  • 2013-11-29 BG BG111638A patent/BG66734B1/bg unknown
• 2014
  • 2014-10-24 WO PCT/BG2014/000038 patent/WO2015077846A1/en active Application Filing

Patent Citations (3)

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