Braille terminal and module for a braille terminal

Abstract

A braille terminal (2) which extends in a transverse direction (6) and which has a plurality of cells (26), wherein each cell (26) has a plurality of pins (28) that can be felt by a user and are arranged in a plurality of columns (32) and a plurality of rows (30), and wherein the cell (26) is designed to represent an individual character, wherein a respective pin (28) can be actuated in each case individually by means of a piezoelectric bending transducer (54), and the piezoelectric bending transducers (54) are secured on a plurality of printed circuit boards (52) has a plurality of modules (4) which are juxtaposed in the transverse direction (6) and which each have a module housing (12), wherein a plurality of cells (26) are integrated in the module (4).

Claims

1. A braille terminal (2) which extends in a transverse direction (6) and which has a plurality of cells (26), wherein each cell (26) has a plurality of pins (28) that can be felt by a user and are arranged in a plurality of columns (32) and a plurality of rows (30), and wherein the cell (26) is designed to represent an individual character, wherein a respective pin (28) can be actuated in each case individually by means of a piezoelectric bending transducer (54), and the piezoelectric bending transducers (54) are secured on a plurality of printed circuit boards (52), characterized by a plurality of modules (4) which are juxtaposed in the transverse direction (6) and which each have a module housing (12), wherein the plurality of cells (26) are integrated in the module (4), wherein the columns (32) extend in a longitudinal direction (8) perpendicular to the transverse direction (6), wherein the plurality of printed circuit boards (52) are arranged above each other in the module housing (12) in a vertical direction which is perpendicular to the transverse direction and the longitudinal direction and, on each printed circuit board (52), a plurality of individual bending transducers (54) arranged next to each other in the transverse direction (6) are contacted and secured, wherein the bending transducers (54) of a respective printed circuit board (52) serve to drive the pins (28) of a respective row of a plurality of cells of the module (4).

2. The braille terminal (2) according to claim 1, wherein the module housing (12) has a closed design, with an upper wall (18) in which passages (60) for the pins (28) are introduced.

3. The braille terminal (2) according to claim 2, wherein, in a region of the passages (60), an operating module (24) is mounted on the upper wall (18), which operating module (24) has the pins (28) extending through it and has an actuating button (34) for each cell (26) of the module (4).

4. The braille terminal (2) according to claim 3, wherein a holding plate (70) is placed inside the operating module (24), through which holding plate (70) the pins (28) are guided individually, and in which the pins (28) are held captive in order to permit removal along with the holding plate (70).

5. The braille terminal (2) according to claim 3, wherein a receiving space (36), in which a master board (38) lies, is formed between the actuating buttons (34) and the upper wall (18).

6. The braille terminal (2) according to claim 5, wherein a plurality of master boards (38) of adjacent modules (4) are connected to each other via plug connectors (44) which are mounted laterally on the master boards (38) in order to permit serial interconnection of the individual modules (4).

7. The braille terminal (2) according to claim 2, wherein the upper wall (18) has a further passage (62) for electrical contacting of the printed circuit boards (52).

8. The braille terminal (2) according to claim 1, wherein, on an upper face of the respective printed circuit board (52), spring contacts (58) are formed in order to permit electrical contacting with an underside of the printed circuit board (52) arranged above.

9. The braille terminal (2) according to claim 1, arranged such that signals and a supply voltage are routed serially and in a loop via the individual printed circuit boards (52).

10. The braille terminal (2) according to claim 1, wherein, on each printed circuit board (52), a driver chip (56) is arranged for driving the pins (28) that are assigned to the printed circuit board (52).

11. The braille terminal (2) according to claim 1, wherein the module housing (12) has a front part (22) and also a receiving cassette (20) which is closed at the front by the front part (22), wherein the printed circuit boards (52) are secured on the front part (22), and the printed circuit boards (52) with the bending transducers (54) secured thereon extend into the receiving cassette (20).

12. The braille terminal (2) according to claim 11, wherein the front part (22) for each printed circuit board (52) has an insert well (64) into which the respective printed circuit board (52) can be inserted, in a process of which a mutual contacting of the printed circuit boards (52) takes place automatically via the spring contacts (58).

13. The braille terminal (2) according to claim 1, wherein the module housing (12) has transverse passages (48) which lie opposite each other in the longitudinal direction (8) and which extend in the transverse direction (6) and have a connecting rod (46) guided through them.

14. A module for a braille terminal (2) according to claim 1, which module has a module housing (12), wherein a plurality of cells (26) are integrated in the module housing (12), wherein each cell (26) has a plurality of pins (28) that can be felt by a user and are arranged in a plurality of columns (32) and a plurality of rows, and wherein the cell (26) is designed to represent an individual character, wherein a respective pin (28) can be actuated in each case individually by means of a piezoelectric bending transducer (54), and the piezoelectric bending transducers (54) are secured on a plurality of printed circuit boards (52), and wherein the columns (32) extend in a longitudinal direction (8) perpendicular to a transverse direction (6), characterized in that the plurality of printed circuit boards (52) are arranged above each other in the module housing (12) in a vertical direction which is perpendicular to the transverse and longitudinal directions and, on each printed circuit board (52), a plurality of individual bending transducers (54) arranged next to each other in the transverse direction (6) are contacted and secured, wherein the bending transducers (54) of a respective printed circuit board (52) serve to drive the pins (28) of a respective row of a plurality of cells of the module (4).

Description

(1) An illustrative embodiment of the invention is explained in more detail below with reference to the figures which depict partly simplified views and in which:

(2) FIG. 1 shows a perspective view of a braille terminal,

(3) FIG. 2 shows a perspective view of a module,

(4) FIG. 3 shows an exploded view of the module shown in FIG. 2,

(5) FIG. 4 shows a perspective view of a printed circuit board, and

(6) FIG. 5 shows a cross-sectional view through the module according to FIG. 2.

(7) Parts that have identical actions are provided with identical reference signs in the figures.

(8) The braille terminal 2 shown in FIG. 1 is composed of a plurality of individual modules 4. Five modules in total are shown in the illustrative embodiment. The individual modules 4 are juxtaposed in a transverse direction 6. The modules 4 themselves extend in a longitudinal direction 8 and have a height extending in a vertical direction 10. Transverse direction 6, longitudinal direction 8 and vertical direction 10 are perpendicular to each other and form a Cartesian coordinate system.

(9) The individual modules 4 (cf FIG. 2) each have a substantially closed module housing 12 which overall has a cuboid shape. The module housing 12 has plane side walls 14 lying opposite each other, a closed bottom (cf FIG. 5) and an upper wall 18. The side walls 14 and the bottom 16 and also a large part of the upper wall 18 form flat surfaces in the illustrative embodiment. In the case of the upper wall 18, this is true at least of a front subregion, which as a whole extends over approximately two thirds of the length of the module housing 12.

(10) The module housing 12 is composed of a receiving cassette 20 and of a front part 22, which closes a front end of the receiving cassette 20.

(11) An operating module 24 is mounted on the upper wall 18, at the side of the module housing 12 opposite the front part 22. This operating module 24 provides a plurality of cells 26, in the illustrative embodiment four cells 26, wherein each individual cell 26 is designed to represent an individual character in the braille alphabet.

(12) For this purpose, a plurality of pins 28 are arranged in rows 30 and columns 32. In the illustrative embodiment, a respective cell 26 has two columns 32 and four rows 30. Therefore, a respective cell 26 has eight pins in total.

(13) An actuating button 34 is assigned to each cell 26. The actuating buttons 34 are formed at the ends on brackets that protrude freely over the upper wall 18. The brackets are all more or less strip-shaped and each receive the pins 28 of a respective cell 26. By means of this configuration of brackets that protrude freely and are to be actuated individually and independently of each other, a receiving space 36 is formed between the brackets and between the operating buttons 34 and the upper wall (see in particular FIG. 2).

(14) A master board 38 is generally arranged on the upper wall 18, which master board 38 is pushed with one end into this receiving space 36 and thus lies between the operating buttons 34 and the upper wall 18. The master board 38 is fixed by means of a clip 40, which in particular spans the entire width of the module housing 12. Opposite the clip 40, the master board is fixed to the module housing via a further fixing element, for example a screw 42, particularly in the region of the front part 22.

(15) The actuating buttons 34 have contact elements on their underside and, when actuated, contact a corresponding contact field of the master board 38.

(16) As will be seen in particular from FIG. 1, the master boards 38 of mutually adjacent modules 4 are serially contacted to each other. Plug connectors 44 are in each case arranged for this purpose. For this purpose, contact pins 44a protruding in the transverse direction are formed on one side, and a contact socket 44b is formed on the opposite side. The electrical contacting takes place automatically when the individual modules 4 are joined together.

(17) The individual modules 4 are held on each other via connecting rods 46, which are routed through transverse passages 48 in the module housing 12. These transverse passages 48 are formed at opposite ends of the module housing 12.

(18) By way of the module housing 12, a free interior is defined which, in the illustrative embodiment, receives a total of four of the printed circuit board modules 50 shown in FIG. 4 and also the pins 28. The printed circuit board modules 50 are arranged above one another in a total of four planes in the vertical direction 10.

(19) As can be seen in particular from the cross-sectional view in FIG. 5, the individual printed circuit board modules 50 are offset in relation to each other in the longitudinal direction 8, such that their free ends terminate at different length positions and at different height positions. This has the effect that a respective printed circuit board module 50 drives, with its free end, precisely one row 30 of the pins 28 across a plurality of cells 26. On account of the offset arrangement in different planes in the vertical direction 10, the pins 28 of the different rows 30 also have different lengths.

(20) As will be seen in particular from FIG. 4, a respective printed circuit board module 50 has a printed circuit board 52 and bending transducers 54. The latter are fixed at one end to the printed circuit board 52 and electrically contacted and protrude freely from the printed circuit board 52 as far as the already mentioned free end. In the illustrative embodiment, precisely eight bending transducers 54 are arranged on each printed circuit board 52. A respective bending transducer 54 serves to drive a respective individual pin 28. Each printed circuit board module 50 moreover has a driver chip 56 and also a number of contact elements, which are designed specifically as spring contacts 58. These are, in particular, bent and stamped sheet-metal parts which are secured to the upper face of the printed circuit board 52. The spring contacts 58 each have an upwardly protruding, resiliently elastic bracket. This provides automatic contacting with the printed circuit board 52 lying above it or, in the case of the uppermost printed circuit board 52, with the master board 38 lying above it. For this purpose, in addition to passages 60 for the individual pins 28, the upper wall 18 of the module housing 12 has further passages 62, such that the spring contacts 58 of the uppermost printed circuit board 52 protrude above the upper face of the module housing 12. The spring contacts 58 contact the underside of the master board 38 lying on the upper wall 18. This permits tapping of the corresponding signals or supplies for the module 4.

(21) In the illustrative embodiment, two groups of spring contacts 58 in total are formed which, viewed in the transverse direction, are arranged at opposite edges of the printed circuit board 52. Accordingly, only two further passages 62 are formed in the upper wall 18.

(22) Eight spring contacts are provided in total. These provide in particular a supply voltage for the driver chip 56 (for example 5 volts), a high-voltage supply for driving the flexible transducers 54 (typically 200 volts), and also a contact connection for a clock, a connection for an input data signal, a connection for an output data signal, and also an enable connection and one or more ground connections.

(23) The individual printed circuit boards 52 are each inserted into insert wells 64 of the front end 22. Upon insertion, the special configuration of the spring contacts 58 ensures that the individual printed circuit boards 52 arranged in the plurality of planes automatically contact each other. The signals, for example data input signals, are routed in a loop through the individual printed circuit boards 52 and back again to the master board 38. The same applies to the supply voltages.

(24) As can be seen in particular from FIG. 3, the operating module 24 is formed at the end of the module housing 12 opposite the front part 22. The operating module 24 has a one-piece, cap-shaped housing, designated as cap 66, which has passages for the individual pins 28 and also the operating buttons 34. This cap 66 is placed onto the module housing 12 from above. For this purpose, the module housing 12 has, for example, two opposite transverse webs 68 onto which the cap 66 is placed from above and thus fixed. The passages 60 for the pins 28 are introduced between the two transverse webs 68. A holding plate 70 is also placed, in particular loosely, between the cap 66 and the upper wall 18. The individual pins 28 are guided individually through this holding plate 70 and held thereon, such that the entire group of pins 28 can be removed together with the holding plate 70. The pins 28 are secured with form-fit engagement in particular in at least one direction. For this purpose, they have a widened portion 72 in the region of their rounded heads, as can be seen in particular from FIGS. 3 and 5.

LIST OF REFERENCE SIGNS

(25) 2 braille terminal

(26) 4 module

(27) 6 transverse direction

(28) 8 longitudinal direction

(29) 10 vertical direction

(30) 12 module housing

(31) 14 side wall

(32) 16 bottom

(33) 18 upper wall

(34) 20 receiving cassette

(35) 22 front part

(36) 24 operating module

(37) 26 cell

(38) 28 pin

(39) 30 row

(40) 32 column

(41) 34 actuating button

(42) 36 receiving space

(43) 38 master board

(44) 40 clip

(45) 42 screw

(46) 44 plug connector

(47) 44a contact pins

(48) 44b contact socket

(49) 46 connecting rod

(50) 48 transverse passage

(51) 50 printed circuit board module

(52) 52 printed circuit board

(53) 54 bending transducer

(54) 56 driver chip

(55) 58 spring contact

(56) 60 passages

(57) 62 further passage

(58) 64 insert well

(59) 66 cap

(60) 68 transverse web

(61) 70 holding plate

(62) 72 widened portion