JP2884404B2 - Braille pin driving method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Braille pin driving method and a Braille pin driving method for driving Braille pins to represent character information such as kana, numbers, alphabets, and the like, figures, and the like.

[0002]

2. Description of the Related Art Braille is mainly composed of a combination of eight braille pins arranged in two columns and four rows to represent character information such as kana, numerals, alphabets, and the like. 2. Description of the Related Art In recent years, various braille pin driving devices have been proposed in which a braille pin is driven up and down so as to be protruded and retracted above and below a display panel so that character information can be variably displayed.

For example, a Braille pin driving device described in Japanese Patent Application Laid-Open No. 54-83531 uses the elastic force of a spring 2 fitted on a Braille pin 1 as shown in FIGS. 16 (A) and 16 (B). Keep the Braille pin 1 raised,
In order to lower the Braille pins 1, an exciting current for generating a downward magnetic force larger than the elastic force of the spring 2 is applied to the winding 3 composed of the row coil and the column coil disposed below the Braille pins 1. This is a configuration of

The braille pin driving device described in Japanese Patent Laid-Open Publication No. Sho 59-116676 comprises an upper driving unit 8 and a lower driving unit 13 as shown in FIG. Upper drive unit 8
In the above, a rod 5 projecting as a Braille pin on the display panel 4 was disposed in a driving solenoid coil 6 and a magnet 7 fixed to the rod 5 was provided so as to keep the rod 5 projecting. Things. The lower drive is
A rod 9 having a magnet 9 for adsorbing and lowering the rod 5 protruding above the display panel 4 by the upper driving unit 8 fixed to an upper end, and a return spring 10 provided at a lower end.
Are arranged in the driving solenoid coil 12.

[0005]

SUMMARY OF THE INVENTION Japanese Patent Application Laid-Open No. 54-8353
In the Braille pin driving device described in Japanese Unexamined Patent Application Publication No. 1-125, in order to keep the Braille pin 1 in a lowered state, it is necessary to always supply an exciting current to both the row coil and the column coil forming the winding 3. Yes, and therefore power consumption is high.

In order to display figures and the like using the Braille pin driving device, the Braille pins 1 are arranged in a matrix, and the row coils, the column coils and the However, there is a disadvantage that the occupied area increases and the driving driver becomes large.

In the Braille pin driving device described in JP-A-59-116676, power needs to be supplied to the driving solenoid coil 6 only when the rod 5 is projected above the display panel 4, so that power consumption is reduced. It can be considered that the driving solenoid coil 6 for projecting the rod 5 above the display panel 4, the magnet 7 for maintaining the protruding state, and the driving solenoid for lowering the rod 5 Since each of the coil 12, the magnet 9, the rod 11, and the return spring 10 is provided, the number of components is increased, the structure is complicated, and the size is increased.

Accordingly, the present invention provides a Braille pin driving method and apparatus suitable for displaying not only Braille text but also figures and the like, in which power consumption is reduced, the structure is simplified and the size is reduced. The purpose is to provide.

[0009]

According to the present invention, there is provided a method for driving a Braille pin, comprising the steps of: an iron core 19 of an electromagnet 18;
When one of the permanent magnets 26 is attracted to one end 19b of the iron core 19 by a combined force of a magnetic repulsive force and an attractive force generated between the two permanent magnets 25 and 26 opposed to each other 9b, In conjunction with this permanent magnet, the braille pins 14, 30
To the tactile position (a) where the finger can touch,
When the other permanent magnet 25 is attracted to the other end 19a of the iron core 19 by the resultant force, the Braille pins 14, 30 are moved in a non-touching position (not touched by a finger) in conjunction with this permanent magnet. The content is to move to b).

In the Braille pin driving devices A and D of the present invention, when the Braille pins 14 and 30 are moved to a tactile position (a) where the finger can be touched, one end 19b of the iron core 19 of the electromagnet 18 is attracted. The first permanent magnet 26 and the Braille pins 14 and 30 which are arranged so as to face each other are placed in the non-tactile position (b) where the finger cannot touch.
When the second permanent magnet 25 is disposed so as to be attracted to the other end 19a of the iron core 19, the pin is moved toward the opposite ends 19a, 19b of the iron core 19 with the same polarity. This is a configuration provided on the bodies 27 and 38.

In this case, the braille pins 14, 30 and the electromagnet 1
It is preferable that eight and two permanent magnets 25 and 26 are arranged in series. In addition, the electromagnet arranging cavities 24b and 37b are formed on the pin moving bodies 27 and 38, and two permanent magnets 25 and 26 are provided in the electromagnet arranging cavities 24b and 37b.
May be arranged facing each other. Further, it is preferable that a plurality of pin driving units B and E including the electromagnet 18 and the pin moving bodies 27 and 38 are provided at equal intervals. Furthermore, when the braille pins 14 and 30 are moved to the tactile position (a) where they can be touched by a finger, the electromagnet 18
The other end 19a of the iron core 19 and one end 2 of the second permanent magnet 25
5a may be set to a dimension that is more than twice the amount of depression of the braille pin 14.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a first embodiment of the Braille pin driving device of the present invention, FIG. 2 is an exploded perspective view thereof, and FIG. 3 is a front view of the Braille pin driving device shown in FIG.
3 is a sectional view taken along line II of FIG. 3, FIG. 5 is a sectional view taken along line II-II of FIG. 3, FIG. 6 is a sectional view taken along line III-III of FIG. 3, and FIG. It is.

The Braille pin driving device A according to the first embodiment of the present invention comprises four pin driving units B for driving the Braille pins 14 arranged in two columns and two rows, respectively, and these four pin driving units. And a support frame C supporting the parts B. By connecting the Braille pin driving devices A, A to each other, the Braille pins 14 are arranged in two columns and four rows, or these are arranged in an arbitrary matrix. They are arranged (FIGS. 1 and 2).

The supporting frame C is composed of an upper frame C 'and a lower frame C ". The upper frame C' has a square at the upper end of a column 15 'formed by forming four partition plates 15'a into a plane cross shape. Top plate 1
6 is formed inside the lower end portion of each partition plate 15'a...
5'b is formed in a rectangular shape.

The four partition plates 15'a are arranged on the lower surface side of the top plate 16 in four arrangement spaces α in which the pin driving units B are respectively arranged.
Are formed on the top plate 16, and each arrangement space α
... a cylindrical braille pin 1 provided on a pin drive section B
A circular pin insertion hole 16a, into which the Braille pin 14 can be loosely inserted, is formed at a position opposite to the pin 4.

Also, four side end surfaces 16b-1 of the top plate 16
6e, another braille pin driving device A is provided on the side end surface 16b.
A projection 16f for connecting to the braille pin is projected from the other three side end surfaces 16c to 16e, and a positioning recess 16g into which a positioning projection 16f of another Braille pin driving device A can be fitted. Are formed.

At each corner formed by the two partition plates 15'a, 15'a, an electromagnet support piece for supporting the other end of the iron core 19 of the electromagnet 18 arranged in each of the arrangement spaces α, ie, the upper end 19a. 20 are protruded from the upper end 19.
The support hole 20a for fitting a is formed.

The lower frame C "is a partition plate 15 'of the upper frame C'.
An electromagnet support piece 21 is formed at the upper end of a column 15 "having a cross-shaped partition plate 15" a having a width that fits into the notch 15'b formed in the column 15a. In addition, a bottom plate 22 having the same shape as the top plate 16 is formed.

The electromagnet support piece 21 has one end of the iron core 19,
That is, the supporting holes 21a for fitting the lower end 19b are formed in the four corners, and the upper edge 1 of the fitting notch 15'b of each partition plate 15'a of the upper frame C 'is formed on the upper surface thereof.
The fitting grooves 21b fitting into 5'c are formed in a cross shape.

The bottom plate 22 has a partition plate 15 'of the upper frame C'.
are formed in the shape of a cross, and the two partition plates 15 ″ a, 1
At the corners formed every 5 ″ a, there are formed through holes 22b... That lead out the terminals 23a of the coil 23 of the electromagnet 18 downward.

Therefore, the support frame C can be assembled by fitting the partition plates 15'a of the upper frame C 'into the fitting grooves 22a on the upper surface of the bottom plate 22 of the lower frame C ".

The pin driving section B is provided with the above-described cylindrical iron core 1.
An electromagnet 18 in which a coil 23 is wound around an intermediate portion of
It has a vertically long main body 24 having a substantially rectangular cross section, upper and lower columnar permanent magnets 25 and 26, and a pin moving body 27 including a Braille pin 14.

The main body 24 is provided with a Braille pin 14, an upper magnet fitting hole 24a for fitting a permanent magnet 25, an electromagnet arrangement space 24b, and a permanent magnet 26 from the upper end to the lower end along the axis thereof. Lower magnet fitting holes 24c to be fitted are sequentially arranged in series.

The electromagnet locating space 24b is provided between the electromagnets 18 supported between the two electromagnet support pieces 20 and 21 of the support frame C.
And the permanent magnets 25 and 26 fitted in the upper magnet fitting hole 24a and the lower magnet fitting hole 24c,
The upper and lower ends 9 have a volume and a shape that can be opposed to the upper and lower ends 19a and 19b while maintaining a required gap.

The arrangement of the iron core 19, the upper and lower permanent magnets 25 and 26, and the braille pin 14 is such that the permanent magnet 25 is opposed to the upper end 19a of the iron core 19 so as to be attracted to the upper end 19a.
The permanent magnets 26 are opposed to each other so as to be attracted to a lower end 19 b of the iron core 9, and the same polarity of the permanent magnets 25, 26 is arranged toward both ends 19 a, 19 b of the iron core 19.

When the lower permanent magnet 26 is attracted to the lower end 19b of the iron core 19, the position where the Braille pin 14 protrudes about 0.8 mm above the top plate 16, that is, the Braille pin 1
4 is moved to a tactile position (a) where the finger can be touched, and when the upper permanent magnet 25 is attracted to the upper end 19 a of the iron core 19, the Braille pin 14 is lowered to the lower side of the top plate 16. , The braille pin 14 is moved to a non-tactile position (b) where the finger cannot be touched.

Further, the gap β between the upper end 19a of the iron core 19 and one end of the upper permanent magnet 25, that is, the lower end 25a when the Braille pin 14 is moved to the tactile position (a).
Is approximately 2 times the maximum possible depression of the braille pin 14.
The size is set to more than double. In other words, for example, when the braille pin 14 is pushed down until it is flush with the surface of the top plate 16, the force pushing down the braille pin 14 is removed, so that the braille pin 14 is moved to the tactile position (a). The magnetic attraction force that causes the electromagnet 18 to return is applied between the lower permanent magnet 26 and the iron core 19 of the electromagnet 18.

In assembling the Braille pin driving device A, the iron core 19 of the electromagnet 18 was supported by the electromagnet support piece 20 of the upper frame C 'and the electromagnet support piece 21 of the lower frame C ". In this state, the upper frame C ′ and the lower frame C ″ are fitted. Thereby, a support frame C in which the four electromagnets 18 are arranged and fixed in the respective arrangement spaces α is assembled, and further, the pin movement in which the permanent magnets 25 and 26 are fitted to the support frame C in advance. By assembling body B, the first
The Braille pin driving device A as the embodiment is completed.

Next, the operation of the Braille pin driving device A will be described with reference to FIGS. The state in which the braille pin 14 is moved to the non-tactile position (b), that is, at the upper end 19a of the iron core 19 of the fixed electromagnet 18,
In a state where the lower end 25a of the upper permanent magnet 25 is attracted, the polarity generated at the upper end 19a of the iron core 19 is different from the polarity of the lower end 25a of the upper permanent magnet 25 opposed thereto. 23 is supplied with an exciting current. Due to this energization, the polarity generated at the lower end 19b of the iron core 19 becomes the same as the polarity of one end of the lower permanent magnet 26 facing the lower end 19b, ie, the upper end 26a.

When the exciting current is applied, a repulsive force is generated between the upper end 19a of the iron core 19 and the lower end 25a of the upper permanent magnet 25, and the lower end 19b of the iron core 19 and the upper end of the lower permanent magnet 26. 26a generates a suction force,
The pin moving body B moves upward by the resultant force, and the Braille pin 14 is inserted into the pin play insertion hole 16a of the top plate 16 from the lower side to the upper side.

As the pin moving body B moves upward, the upper end 26a of the lower permanent magnet 26 facing the lower end approaches the lower end 19b of the iron core 19 and the upper end 19a of the iron core 19.
The upper permanent magnet 25 that has been attracted to the iron core 19 separates above the upper end 19 a of the iron core 19.

When the Braille pin 14 moves to the tactile position (a), the lower permanent magnet 26 is attracted to the lower end 19b of the iron core 19, and this attracted state indicates that the exciting current is supplied to the coil 23. Is retained by the magnetic force of the permanent magnet 26 even after the power is turned off. In other words, it is possible to keep the Braille pins 14 protruding above the top plate 16 even after the supply of the exciting current to the coil 23 is cut off.

Contrary to the above, when the Braille pin 14 is moved to the tactile position (a), the polarity generated at the upper end 19a of the iron core 19 and the lower end of the upper permanent magnet 25 opposed thereto are set. An exciting current is supplied to the coil 23 so that the polarity of the coil 25a becomes the same. Due to this energization, the polarity generated at the lower end 19b of the iron core 19 is different from the polarity of the upper end 26a of the lower permanent magnet 26 opposed thereto.

By this energization, the upper end 19a of the iron core 19 is
And a lower end 25a of the upper permanent magnet 25, a repulsive force is generated, and an attraction force is generated between the lower end 19b of the iron core 19 and the lower permanent magnet 25. The body B is moved downward, and the braille pin 14 moves downward from the tactile position (a).

With the downward movement of the pin moving body B, the lower end 25a of the upper permanent magnet 25 approaches the upper end 19a of the iron core 19, and the lower permanent magnet 26 adsorbed on the lower end 19b of the iron core 19 is moved. Away from the lower end 19b. Then, when the braille pin 14 is moved to the non-tactile position (b), the lower end 25a of the upper permanent magnet 25 is attracted to the upper end 19a of the iron core 19, and this attracted state indicates the exciting current of the coil 23. It is maintained by the magnetic force of the permanent magnet 25 even after the energization is cut off.

Displaying a Braille sentence, a graphic, or the like using the Braille pin driving device A according to the first embodiment is performed as follows. The display panel 28 of the braille display shown in FIG.
Are formed at regular intervals so that the two braille pin driving devices A can be inserted in a connected state. By inserting two Braille pin driving devices A into each of the fitting portions 28a, eight Braille pins 14 can be arranged in two columns and four rows.

In order to display a graphic or the like having a large area which cannot be represented by only the eight braille pins 14, a required number of braille pin driving devices A are arranged on a display panel 29 of a braille display shown in FIG. It is sufficient to form a square fitting portion 29a that can be arranged in a shape, and to insert a predetermined number of Braille pin driving devices A into this.

A second embodiment of the Braille pin driving device according to the present invention will be described. 11 is a perspective view of a braille pin driving device according to a second embodiment of the present invention, FIG. 12 is a partially exploded perspective view thereof, and FIG. 13 is a sectional view taken along line VV of FIG. The Braille pin driving device D according to the second embodiment of the present invention has two rows and four rows.
The braille pins 30 are arranged in rows, each of which includes eight pin driving units E for driving up and down, and a support frame F that supports these pin driving units E. The braille pins 30 are arranged in two columns and four rows. Or they can be arranged in an arbitrary matrix (FIG. 11).

The support frame F has side walls 33, 33 standing between both ends of the top plate 31 and the bottom plate 32, and also defines an arrangement space α 'in which the pin driving parts E are arranged. In addition, three partition plates 34 are erected between the side walls 33, 33 at equal intervals, and the side ends 33, 33
A partition plate 35 is formed between the intermediate portions 33 so as to be orthogonal to the partition plates 34.

A circular pin play insertion hole 31 into which the Braille pin 30 can be loosely inserted is provided in the top plate 31 at a position facing the Braille pin 30 provided in the pin driving section E arranged in each of the arrangement spaces α '.
a are formed, and positioning flanges 31b, 31b are horizontally protruded from both ends of the top plate 31.

Electromagnetic support pieces 36, 36 are provided at the upper and lower ends of the partition plate 35 facing the respective arrangement spaces α '.
Each electromagnet support piece 36 is constituted by a pair of elastic holding pieces 36b, 36b each having a semicircular holding groove 36a capable of holding the iron core 19 of the electromagnet 18 formed on the opposing surface at the distal end. Bottom plate 3
2, lead-out holes 32 a are formed in the corners of the partition plate 34 and the partition plate 35 so as to lead out the terminals 23 a of the coil 23 of the electromagnet 18 downward.

The pin driving unit E includes the electromagnet 18 described above,
Vertical main body 37, permanent magnets 25 and 26, and braille pin 30
And a pin moving body 38 composed of The main body 37
From the upper end to the lower end along the axis,
0, an upper magnet fitting hole 37a for fitting the permanent magnet 25, an electromagnet arrangement space 37b, and a lower magnet fitting hole 37c for fitting the permanent magnet 26 are formed in series in this order.

The electromagnet locating space 37b is provided between the two electromagnet support pieces 36, 36 of the support frame F.
And the permanent magnets 25 and 26 fitted into the upper magnet fitting hole 37a and the lower magnet fitting hole 37c
The upper and lower ends 19a and 19b of the iron core 19 have a volume and a shape which can be opposed to each other while maintaining a required gap.

The arrangement of the iron core 19, the permanent magnets 25 and 26, and the braille pins 30 is the same as in the first embodiment described above, so that the permanent magnet 2 is attracted to the upper end 19a of the iron core 19.
5 and the permanent magnets 26 so as to be attracted to the lower end 19b of the iron core 19, and the same polarity of the permanent magnets 25 and 26 is applied to both ends 19 of the iron core 19.
a, 19b.

When the Braille pin 30 is moved to the tactile position (A), the permanent magnet 26 is attracted to the lower end 19b of the iron core 19, and the Braille pin 30 is moved to the non-tactile position (B). In this case, the permanent magnet 25 is set so as to be attracted to the upper end 19a of the iron core 19. Further, the gap between the upper end 19a of the iron core 19 and the lower end 25a of the upper permanent magnet 25 when the Braille pin 30 is moved to the tactile position (a) is
The size of the braille pin 30 is set to be approximately twice as large as the assumed maximum depression amount, as in the case of the braille pin driving device according to the first embodiment.

The braille pin driving device D is assembled in 2
The iron core 19 of the electromagnet 18 is attached to the two electromagnet support pieces 36, 36.
Are pushed into each other so that the supporting frame F supporting the eight electromagnets 18 is assembled.
Further, a pin moving body E in which permanent magnets 25 and 26 are fitted in advance is assembled into
Is completed. The operation of the braille pin driving device D according to the second embodiment is the same as that of the first embodiment, and a description thereof will be omitted.

In order to display a Braille sentence using this Braille pin driving device D, as shown in FIG. 14, the Braille pin driving device D... Thus, the required number of braille characters can be displayed at one time.

The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the invention. In the Braille pin driving device described above, a configuration in which Braille pins are arranged in two columns and two rows and two columns and four rows has been described. For example, a configuration in which Braille pins are arranged in two columns and three rows may be employed. You may. In addition, the pin driving section has two rows and two rows.
Although the embodiment in which the rows and columns are arranged in four rows has been described, the number of rows and columns may be different from these.

[0049]

According to the first to sixth aspects of the present invention, a magnetic attractive force and a repulsive force are generated between the iron core of the electromagnet and the two permanent magnets, and the braille pin is formed by the resultant force. Since it can be moved, a large driving force can be obtained, and the power consumption required for moving the Braille pin can be reduced.

Since the Braille pins at the tactile position and the non-tactile position are held by attracting two permanent magnets to the iron core of the electromagnet, it is only necessary to instantaneously apply an exciting current to the coil. Power consumption can be further reduced.

When the Braille pin is moved between the tactile position and the non-tactile position, one of the two permanent magnets is attracted to the iron core, so that the Braille pin can be accurately positioned. In addition, the braille pin can be securely held.

According to the second aspect of the present invention, the Braille pins can be driven only by the two permanent magnets incorporated in the pin moving body and the electromagnets opposed to the permanent magnets. Can be achieved.

According to the third aspect of the present invention, a braille pin,
Since the electromagnet and the two permanent magnets are arranged in series,
The interval between the braille pins can be set to an appropriate interval at which the braille pins can be easily touched.

According to the fourth aspect of the present invention, since the electromagnets are arranged in the electromagnet locating space of the pin moving body, the apparent volume can be reduced, which contributes to downsizing. it can.

According to the fifth aspect of the present invention, since a plurality of pin driving units each composed of an electromagnet and a pin moving body are provided at equal intervals, the Braille pin driving devices are connected to each other. A display area consisting of an arbitrary matrix can be easily formed.

According to the invention described in claim 6, when the Braille pin is moved to the tactile position touched by the finger, the gap between the other end of the iron core of the electromagnet and one end of the second permanent magnet is changed. Since the size of the braille pin is set to be more than twice as much as the pushing amount, just removing the force pushing down the braille pin,
The Braille pin is returned to the tactile position.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of a Braille pin driving device of the present invention.

FIG. 2 is an exploded perspective view of the same.

FIG. 3 is a front view of the same.

FIG. 4 is a view taken along line II of FIG. 3;

FIG. 5 is a sectional view taken along line II-II of FIG. 3;

FIG. 6 is a sectional view taken along line III-III of FIG. 3;

FIG. 7 is a sectional view taken along line IV-IV of FIG. 3;

8A and 8B show an operation of the pin moving body, in which FIG. 8A is an operation diagram in which the pin moving body is moved to the non-tactile position, and FIG. 8B is an operation diagram in which the pin moving body is moved to the tactile position. is there.

FIG. 9 is a plan view of an example of a display panel incorporating the first embodiment of the Braille pin driving device.

FIG. 10 is a plan view of another example of the display panel incorporating the first embodiment of the Braille pin driving device.

FIG. 11 is a perspective view showing a braille pin driving device according to a second embodiment of the present invention.

FIG. 12 is a partially exploded perspective view of the same.

FIG. 13 is a sectional view taken along line VV of FIG. 11;

FIG. 14 is a plan view of an example of a display panel incorporating the second embodiment of the Braille pin driving device.

FIG. 15 is a front view of the same.

16A and 16B show an example of a conventional Braille driving device, wherein FIG. 16A is a cross-sectional view in which a Braille pin is raised, and FIG. 16B is a cross-sectional view in which it is lowered.

FIG. 17 is a cross-sectional view showing another example of the conventional Braille driving device.

[Explanation of symbols]

 14, 30 Braille pin 18 Electromagnet 19 Iron core 23 Coil 24b, 37b Electromagnet arrangement emptying 25 Second permanent magnet 26 First permanent magnet 27, 38 Pin moving body β gap (A) Tactile position (B) Non Tactile position

Claims (6)

(57) [Claims] 1. One of the permanent magnets is formed by the combined force of a magnetic repulsive force and an attractive force generated between an iron core of an electromagnet and two permanent magnets disposed opposite to both ends of the electromagnet. When attracted to one end, in conjunction with this permanent magnet, the Braille pin was moved to a tactile position touched by a finger, and the resultant force attracted the other permanent magnet to the other end of the iron core. In some cases, a Braille pin driving method is characterized in that the Braille pin is moved to a non-tactile position where it cannot be touched by a finger in conjunction with the permanent magnet. 2. A braille pin driving device having a pin moving body supporting a braille pin and an electromagnet for moving the pin moving body, wherein the braille pin is moved to a tactile position touched by a finger. When the first permanent magnet and the Braille pin, which are opposed to each other and are attracted to one end of the iron core of the electromagnet, are moved to a non-tactile position where they cannot be touched by a finger, they are attracted to the other end of the iron core. And a second permanent magnet disposed to face the
A braille pin driving device, wherein the same polarity is provided to both ends of an iron core on the pin moving body. 3. The Braille pin driving device according to claim 2, wherein a Braille pin, an electromagnet and two permanent magnets are arranged in series. 4. The pin moving body is formed with an electromagnet arrangement cavity, and two permanent magnets are arranged so as to face each other in the electromagnet arrangement cavity. Braille pin drive. 5. A plurality of pin driving units comprising an electromagnet and a pin moving body are provided at equal intervals from each other.
A braille pin drive as described. 6. When the Braille pin is moved to a tactile position touched by a finger, the gap between the other end of the iron core of the electromagnet and one end of the second permanent magnet is substantially reduced by the amount of depression of the Braille pin. 2
The size is set to more than twice the size.
A braille pin drive as described.