CA1075459A - Electromechanical transducer for relief display panel - Google Patents
Electromechanical transducer for relief display panelInfo
- Publication number
- CA1075459A CA1075459A CA258,505A CA258505A CA1075459A CA 1075459 A CA1075459 A CA 1075459A CA 258505 A CA258505 A CA 258505A CA 1075459 A CA1075459 A CA 1075459A
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- Canada
- Prior art keywords
- reed
- rod
- voltage
- piezoelectric
- reeds
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- Devices For Indicating Variable Information By Combining Individual Elements (AREA)
Abstract
Abstract of the Disclosure A reading plate has an array of holes in its surface.
Rounded ends of rods project selectively through these holes by the action of a set of bimorphous piesoelectric reeds, on which they rest perpendicularly. Each reed is connected to a source of electric voltage which can assume two distinct values as a function of an electrical control signal in order to make the piezoelectric reeds bend in one direction or the other. The reeding rods are distributed in groups of six and arranged in each group according to the conventional arrangement of dots of a braille character. The transducer can thus provide a relief read-out panel for a pocket electronic calculator for the blind.
Rounded ends of rods project selectively through these holes by the action of a set of bimorphous piesoelectric reeds, on which they rest perpendicularly. Each reed is connected to a source of electric voltage which can assume two distinct values as a function of an electrical control signal in order to make the piezoelectric reeds bend in one direction or the other. The reeding rods are distributed in groups of six and arranged in each group according to the conventional arrangement of dots of a braille character. The transducer can thus provide a relief read-out panel for a pocket electronic calculator for the blind.
Description
1~75~59 The present invention relates to an electro~nechanical transducer device, to a relief display device using such an elec~
tromechanical transducer device, and to a por-table minicasset-te magne-tic tape player/recorder using such an elec-tromechdnical -transducer device.
~ lectronic pocket calculators which are obtained with the presenk inventlon could be of immense service to the blind who encounter the greatest difficulty in making numerical calcula-tions, especially when these calculations require the use of magnitudes which must be sought in tables (for example logarithms, trigonometric functions, etc.).
Such calculators are at present useless to blind persons since the results are presented in the form of a visual image of luminous figures in a window.
The method of writing and reading currently employed by the blind throughout the would is the braille system. In this system each sign (letter, figure or sign of punctuation) is represented by a geometric figure constituted of points in relief to a maximum number of six. These geometric figures are easily recognized to the touch by the blind who can, with training, read very rapidly, Unfortunately, braille books are bulky and expensive to produce, which limits the access of blind people to written information. To overcome these drawbacks and to produce texts in relief from electrical signals, electro-mechanical methods are known enabling the production of braille characters in relief. The known methods have all nurnerous drawbacks: mechanical complexity, bulk, weight, noise, high consumption of electricity~
More recen-tly, it has been proposed to use vibrating points with piezoelectric actuation to constitute characters intended to be read by touch (U.S. Patent 3,229,387). This device has still serious drabacks. Firstly, -the majori-ty of blind people find their sense of touch fa-tigued and evenirrita-ted by the vibrations. ~urther, -they are obliged to adap~
.
themselve~ to a mode of reading which i~ very different from that of books in relief: instead of drawing khe finger over a line of character~ in relief, thereby being abl~ to ~low down, accelerate, stop, or back-track at will, they must - by reason of the fragility of the vibrating pointa - leave the finger immobile on the vibrating points, the latter then ~ucce~sively presenting the ch~racters of -the text. La~tly, the vîbrating point~ emit a distinctly audible sound, which then con~titute~
a nuisance ln the vicinity~ particularly i~ several persons work close together.
It is an ob~ect of the presen~ invention to provlde a display device presenting to the blind person, line~ of characters i~ r~lief with characteri~tics identical to those that they are accu~tomed to encount0r in br~ille book~ of the best quality.
; Another object o~ this invention is to provide a relief di~play device which is light and of little bulk.
Another object of this invention i~ to provide a silent relief displsy device.
Another ob~ect of this invention is to provide a relief di3play device consuming very little electrical energy.
Another ob~ect of this invention i~ to provide ~
relief di~play device which i9 robu~t ~nd capable of with-stsnding any false manoeuver of the user~
Another object of thi~ invention is to provide a modular relie~ di~play device 9 that i9 to ~ay constituted of identical modular elements which can be juxtaposed ~o a3 to obtaln lines of character~ of the de~ired length.
Yet another obJect of thi~ invention is to provide an entirely dismountable rellef di~play device to facilitate maintenance or replacement of the element~ constituting the de~ice.
7~i~S:~
Accord:ing to the preC;ent invention there a provided an electromechanical transducer device comprising: a bimorphous plezoelectirc reed bendab]e arouncl an axis perpendicular to the longltudinal axis of ~le reed on the application of a ~C vol.tage, support means for each end of the reed, coupllng means supported on the said reed, a rod arranged transversely to the piezoelc-~c-tric reed and coupled to the coupling means, and means for applaying a DC vol-tage -to -the reed, whereby on the application of the voltage the bending of the reed causes static displacement of the rod in the direc-tion of its own longitudinal axis.
~ccording to the present invention there is also provid-ed a relief display device module comprising: a support housing including a tactually scanable plate having a plurality of holes therethrough arranged in an array, a plurality of electromecha-nical transducer devices housed in the housing, each electro-mechanical transducer device comprising a bimorphous piezoelec-tric reed bendable around an a~is perpendicular -to the longi-tudinal axis of the.reed on the application of a d.c. voltage, support means for each end of said reed, coupling means supported on the reed, and a rod arranged transversely to the piezoelectric reed and coupled to the coupling means, the rod having an end traversing slidably a respective, corresponding one of the holes between a first static position in which the rod end projects a tactually detectable distance from its hole and a second static position in which the rod end does not project from its hole, by the application of a d.c. voltage to the reed, and a printed circuit adapted to be held against the housing, bearing a plura-lity of electrical actuating circuits for the respective piezo-. elec-tric reeds.
; 30 According to the present invention there is also provid-ed a portable mini.cassette magnetic tape player/recorder compri.s-ing in combination: a bra;lle keyboard: a tape transport uni-t, ~ . -3 ~
", ~e~s~s~
a control circui t and a re:Lief display clevice which comprises:
a support housing including a tactually scanable plate having a plurali ty of holes therethrough arranged in an array a plurality of el.ectromechanica:L transducer devices housed irl said housing, each electromechanical transducer devlce compr;.s--ing a birnorphol~s piezoe:lectri( reed bendable around an ax:is perpendicular to the longi.tudinal axis of -the reed on -the appli-ca-tion of a d.c. voltage, suppor-t means for each end of said reed, coupling means supported on said reed, and a rod arranged transversely to said piezoelectric reed and coupled to said coupling means, said rod having an end traversing slidably a respective corresponding one of said holes between a first static position in which said rod end pro.jects a -tactually detectable distance from its hole and a second static position in which said rod end does not project from its hole, by the applica-tion of a d.c. voltage to said reed, a printed circuit adapted to be held against said hous-ing, bearing a plurality of electrical actuating circuits for the respective piezoelectric reeds, and a metal touch switch adjacent to the scanable plate for changing or transferring the displayed data.
In an electronic calculator constructed according to the present invention, the results can be presented in the form of braille figures in relief, appearing in a window similar to that of ordinary pocket calculators. In these calculators, the actuating key-board can include several tens of keys each for actuating a different operation: entry of a figure in-to the calculator, addition, subtraction, multiplication, division, root extraction, etc...
,,";~,7 -3a-, ,,~
~7S'~i9 In a calculator according to the pre~ent invention, each of the possible operatlons is actuated by compo~ing ~
braille character by mean~ of a seven-key key-board ~imilsr to that of a braille -typewriter.
The invention will be better understood on reading the description which follows, in con~unction with the accom~
panying drawings~ of a ~pecific embodiment of the invention, which i~ in no way to be regarded as ~imiting.
In the drawing~:
FIGURE 1 is a block diagra~ of an embodiment of an electronic calculator according to the invention.
~IGURE 2 is a plan view of the control panel of an electronic calculator according to the invention.
FIGURE 3 is a ~chematic diagram of a coding circuit for ~n embodiment of an electronic calculator according to the invention.
FIGURE 4 is a simplified diagram of a conventional vi~ual display element of a pocket electronic calculator.
FIGURE 5 is a simplified vertical cross-section of an embodiment of an electromechanical transducer for a display device according to the invention.
. ~ ~IGURE 6 ghows a circuit diagram of an actuating circuit suitable for the embodiment of FIGURE 5.
FIGURE 7 ~hows in slmplified plan two juxtaposed modules to form two con3ecutive braille character~ from the embodiment~ of ~IGURE 5.
FIGI~E 8 shows a ver-tical sectional view along the line AA' of ~IGU~ 7, The general arrangement oi` the element~ composing an electronic calculator according to the present invention will first be described Thi~ arrangement will be better understood by refering to the diagram of ~IGURE 1.
1a~75~59~
The "heart" of a calculator i9 consti~uted by the arithmetic unit (AU) capable of carryin~ out all the desired operations. This arithme-tic unit i9 a current model used in commercial pocke-t electronic calculatora. The po~sibili-ties o~ the c31cu]Dtor will be ~ hc grent~:r ~a a morc improved aIithmetic unit is u~ed.
By pressing on one or ~everal keys of the kegboard (KB) the braille character corre3ponding to the selected operation i~ composed, The electronic coding circuit ~CO) convert~ this character into a number corre~ponding to the operation selected in the input code of the arithmetic unit (AU), ~he result of the operation supplled by the arithmetic unit (AU) in it~
output code, 19 converted into braille by the decoding circuit (DCO), which sctuates the appearance of the braille figures in relief~on the display panel for the results (DP).
The power supply (PS) i9 of a type currently u~ed in commercial pocket calculators.
An electric calculator according to the present invention, i9 in the form of a rectangular box of small thick-ness, ~ho~e upper surface comprises the di~play panel for the result~ (DP), the actuating keyboard compri~ing the seven key~
(K1) to (K6) and (E) ~nd the on-off ~witch (SW). ~IGURE 2 indicate~ by way of non-limi-ting ex~mple~ a suitable arrange-ment of these element~.
The elements constituting an electronic calculstor according to the pre~ent invention, will now be de~cribed in detailed manner.
KEYBOARD (KB) The ~ix key3 (K1) to (K6) enable the composition of 63 different character~ and consequently the actuation of as m~ny different operations of the calculator. The~e pos~ibilitie~ are ~o~s~
greater than tho~e of the ~ctuating keyboard of commercial pooket electronic calculator~ generally comprising from 20 to 40 key~.
The key (E) la reaerved for the zero rese-t of the calculator.
CO~TNG CI~CU T (~0) Thia circuit i~ ~or convertlng the lnat~uction~ in braille coAe Prom the keyboard (KB) into instructions in the input code of the arithmetic unitD
Such a circuit ia shown, by way of non-limiting eYample, in ~IGURE 3~ The microelectronic components used are currently av~ilable in the trade.
This circult includea a 4-~ay analog switch (C1) actuated by the keya (K1) and (K6) connected to a ten-wsy analog ~witch (C2) actuated b~ the keya (K2), (K3), (K4), and (K5~.
Thi~ arrangement i9 used when the input code of the arithmetic unit is decimsl. The llne~ A~B,C~D ~elected by ~C1) correaponds to the tens, the lines 0~1,2,3,4,5~6,7,8,9 selected by (C2) corre~pond to the unita~ ~he arithmetic unit can thus be given 40 different order~ in decimal cod~, by composing by mean~ of the ~ix keys (K) one of the 40 ~iret braille character00 The ten first braille charactera will corre0pond Por examp~e to the input into the calculator of the ~igure~ ~rom 0 to 9~ the 10 following char~cter~ to 10 operations such a9 addition, subtraction~ multiplication7 divisionD ~tc..., the 10 following characters to the computation order of an operstion - ~uch as inver~ion, squsre~ square root, etc.. ~ and 90 on.
~) In commercial pocket electronic calculator~, the 30 Pigures of the di~play panel oP the results ~re generally conatituted by light-emit~ing diodes or liquid crystal0 com prising 7 rectilinear aegmenta and a decimal polnt according to .
~75i45~
the arrangement of FIGURE 4.
To obtaln the desired flgure lt suffice~ to illuminate the appropriate ~egment~. The ~igure 1, for eYample ~ i9 obtained by illuminating the ~egment~ SB and SC, the figure 3 by illumlnating the aegmenta SA,SB,SC,SD,~G, the minua aign (-) by illumin~ting the aegment SG, etc.,, The ari-thmetic unlts available in the trade are de~igned for thi~ type of diaplay and hence supply the resulta in the correspondlng eight-line code. In an electronic cal-culator according to the preaent inventlon, the decoding cir-cuit is re~ponsible for converting the results into the braille code, A code converte~ oP this type can be, for example, - constructed with a read-only memory of 64 x 6 bit~, DISP~AY PANEL (DP) Each braille character of the display panel for the re~ultg i9 obtained by mean~ of an electromechanical tran~-ducer device according to the present invention of which an embodiment is ~hown in ~igure 5, A cylindrical rod (T) of 1,4 mm diameter can ~lide vertically in two hole 9 pierced in two horizontal plate~ o~ a support housing (H) of molded plsatica material, The upper end of the rod (T) i~ of hemi~pheric ahape ~nd polished ~o a~ to constitute one braille point ln relief ea~y to detect when the rod (T~ extends beyond the upper surface of the ~upport (H) by about 0,7 mm~
The rod (T) i9 fa~tened in a ~mall block of insulating material (P) through which it pa~se~ perpendicularly, e.g.
screwably by a tapping of the block and corre~ponding threading on the rod at lea~t over the axial length of lt~ passage thro~gh the block, with a screwing 310t in either end of the rod~
enabling adju~tment of the projectlon of the rounded end of the rod above the upper aurface of the support ~H), A thin strip 75~5~
or reed of bimorphous piezoelectr~ c ceramic (L) re~ts horizontally in a groove of the block (P) closely ad~acent the rod ~T). This strip i~ gripped at each o~ it~ end~ between two met~llic ~pring~ (R) held inside housings formed in the vertical pillars of the ~upport of molded pl~tic~ materi~l (H)o Block (P) ia located midway between the ends of strlp (L). Two of the spring~
(R) also serve to ensure the electrical connection~ between the upper and lower electrode~ of the ~trip (L) and -the two leads at the respective electric potential~ V1 and V2 (~ee FIGURE 6).
When V1 = V2 the piezoelectric strip (L) i9 rectilinear and ~t re~t. If V1 i~ le~s than V2 the strip t~) curva~ in a vertical plane and pushes the block (P) and hence the rod (~) verticslly upwards. If on the contrary V1 i~ greater than V2 the ~trip (L) curve~ in the opposite direction and pulle the block (P) and the rod (T) verticslly downward~.
~ y u~ing a piezoelectric strip of 70 mm length, 1.7 mm width, and 0.67 mm thickne 99 of lead zirconate-tltanate ~vailable commercially, a verticsl movement of 0.5 mm i~ obtained for a di~ference of 250 volt3 between V1 and V2.
In order to obtsin a very di~tinct retraction or relie~ of the braille point it is desirable to have an overall travel of the rod (T) of about 1 mm, Stop mesn~ can be provi-ded on the rod to limit e~ces~ive bending of the piezoelectric strip which msy break it, through e~ternal pres~ure on -the end of the rod. The~e ~top me~ns may be con~tituted by the threading on the rod forming ~houlders which can come into abutment with the edges of the holes in the hori~ontal plates of the hou~ing (H). Said travsl can be obtained by using the actuating circuit ~hown in FIGURE 6.
3o Thls circuit compris~ two high-voltage tran~istors (TR1) and (TR2), two losd resi~tor~ (R13 and (R2) of which ~
typicsl v~lue i~ 22Q 9 t~o re~istor~ in the ba~e circuit~ of the tran3i~tors (R3) and (R4) of which a typical v~lue i~ 470 kQ
and a digital inverter ~I) An electrlcal control voltage Vc ie applied at the point indlcated in the dia~r~m of ~IGURE 6. Thia voltage i~
~uppll~d by the decodin~ oircult (DaO) de~cribed previoualy.
A po~itive voltage Vc renders the tran~i~tor (TR1) conductive and blocks the tran~istor (TR2) One then obtain~
V1 = and V2 = 250 volt~ for ~ supply voltage V~ of 250 volts.
A zero voltage Vc produces the reverse re~ult, tha-t i~ to say V1 -- 250 volts and V2 = 0 The de~ired vertical travel of 1 mm for the rod (T) i9 thus obtained.
T~o of the principal advantage 9 of the braille point di~play device according to the presen~ invention are:
1) Very low electrioal consumption: about 3mW for the circuit described. Thi~ consumption i~ le~s -than thst of a luminous ~egment.
tromechanical transducer device, and to a por-table minicasset-te magne-tic tape player/recorder using such an elec-tromechdnical -transducer device.
~ lectronic pocket calculators which are obtained with the presenk inventlon could be of immense service to the blind who encounter the greatest difficulty in making numerical calcula-tions, especially when these calculations require the use of magnitudes which must be sought in tables (for example logarithms, trigonometric functions, etc.).
Such calculators are at present useless to blind persons since the results are presented in the form of a visual image of luminous figures in a window.
The method of writing and reading currently employed by the blind throughout the would is the braille system. In this system each sign (letter, figure or sign of punctuation) is represented by a geometric figure constituted of points in relief to a maximum number of six. These geometric figures are easily recognized to the touch by the blind who can, with training, read very rapidly, Unfortunately, braille books are bulky and expensive to produce, which limits the access of blind people to written information. To overcome these drawbacks and to produce texts in relief from electrical signals, electro-mechanical methods are known enabling the production of braille characters in relief. The known methods have all nurnerous drawbacks: mechanical complexity, bulk, weight, noise, high consumption of electricity~
More recen-tly, it has been proposed to use vibrating points with piezoelectric actuation to constitute characters intended to be read by touch (U.S. Patent 3,229,387). This device has still serious drabacks. Firstly, -the majori-ty of blind people find their sense of touch fa-tigued and evenirrita-ted by the vibrations. ~urther, -they are obliged to adap~
.
themselve~ to a mode of reading which i~ very different from that of books in relief: instead of drawing khe finger over a line of character~ in relief, thereby being abl~ to ~low down, accelerate, stop, or back-track at will, they must - by reason of the fragility of the vibrating pointa - leave the finger immobile on the vibrating points, the latter then ~ucce~sively presenting the ch~racters of -the text. La~tly, the vîbrating point~ emit a distinctly audible sound, which then con~titute~
a nuisance ln the vicinity~ particularly i~ several persons work close together.
It is an ob~ect of the presen~ invention to provlde a display device presenting to the blind person, line~ of characters i~ r~lief with characteri~tics identical to those that they are accu~tomed to encount0r in br~ille book~ of the best quality.
; Another object o~ this invention is to provide a relief di~play device which is light and of little bulk.
Another object of this invention i~ to provide a silent relief displsy device.
Another ob~ect of this invention is to provide a relief di3play device consuming very little electrical energy.
Another ob~ect of this invention i~ to provide ~
relief di~play device which i9 robu~t ~nd capable of with-stsnding any false manoeuver of the user~
Another object of thi~ invention is to provide a modular relie~ di~play device 9 that i9 to ~ay constituted of identical modular elements which can be juxtaposed ~o a3 to obtaln lines of character~ of the de~ired length.
Yet another obJect of thi~ invention is to provide an entirely dismountable rellef di~play device to facilitate maintenance or replacement of the element~ constituting the de~ice.
7~i~S:~
Accord:ing to the preC;ent invention there a provided an electromechanical transducer device comprising: a bimorphous plezoelectirc reed bendab]e arouncl an axis perpendicular to the longltudinal axis of ~le reed on the application of a ~C vol.tage, support means for each end of the reed, coupllng means supported on the said reed, a rod arranged transversely to the piezoelc-~c-tric reed and coupled to the coupling means, and means for applaying a DC vol-tage -to -the reed, whereby on the application of the voltage the bending of the reed causes static displacement of the rod in the direc-tion of its own longitudinal axis.
~ccording to the present invention there is also provid-ed a relief display device module comprising: a support housing including a tactually scanable plate having a plurality of holes therethrough arranged in an array, a plurality of electromecha-nical transducer devices housed in the housing, each electro-mechanical transducer device comprising a bimorphous piezoelec-tric reed bendable around an a~is perpendicular -to the longi-tudinal axis of the.reed on the application of a d.c. voltage, support means for each end of said reed, coupling means supported on the reed, and a rod arranged transversely to the piezoelectric reed and coupled to the coupling means, the rod having an end traversing slidably a respective, corresponding one of the holes between a first static position in which the rod end projects a tactually detectable distance from its hole and a second static position in which the rod end does not project from its hole, by the application of a d.c. voltage to the reed, and a printed circuit adapted to be held against the housing, bearing a plura-lity of electrical actuating circuits for the respective piezo-. elec-tric reeds.
; 30 According to the present invention there is also provid-ed a portable mini.cassette magnetic tape player/recorder compri.s-ing in combination: a bra;lle keyboard: a tape transport uni-t, ~ . -3 ~
", ~e~s~s~
a control circui t and a re:Lief display clevice which comprises:
a support housing including a tactually scanable plate having a plurali ty of holes therethrough arranged in an array a plurality of el.ectromechanica:L transducer devices housed irl said housing, each electromechanical transducer devlce compr;.s--ing a birnorphol~s piezoe:lectri( reed bendable around an ax:is perpendicular to the longi.tudinal axis of -the reed on -the appli-ca-tion of a d.c. voltage, suppor-t means for each end of said reed, coupling means supported on said reed, and a rod arranged transversely to said piezoelectric reed and coupled to said coupling means, said rod having an end traversing slidably a respective corresponding one of said holes between a first static position in which said rod end pro.jects a -tactually detectable distance from its hole and a second static position in which said rod end does not project from its hole, by the applica-tion of a d.c. voltage to said reed, a printed circuit adapted to be held against said hous-ing, bearing a plurality of electrical actuating circuits for the respective piezoelectric reeds, and a metal touch switch adjacent to the scanable plate for changing or transferring the displayed data.
In an electronic calculator constructed according to the present invention, the results can be presented in the form of braille figures in relief, appearing in a window similar to that of ordinary pocket calculators. In these calculators, the actuating key-board can include several tens of keys each for actuating a different operation: entry of a figure in-to the calculator, addition, subtraction, multiplication, division, root extraction, etc...
,,";~,7 -3a-, ,,~
~7S'~i9 In a calculator according to the pre~ent invention, each of the possible operatlons is actuated by compo~ing ~
braille character by mean~ of a seven-key key-board ~imilsr to that of a braille -typewriter.
The invention will be better understood on reading the description which follows, in con~unction with the accom~
panying drawings~ of a ~pecific embodiment of the invention, which i~ in no way to be regarded as ~imiting.
In the drawing~:
FIGURE 1 is a block diagra~ of an embodiment of an electronic calculator according to the invention.
~IGURE 2 is a plan view of the control panel of an electronic calculator according to the invention.
FIGURE 3 is a ~chematic diagram of a coding circuit for ~n embodiment of an electronic calculator according to the invention.
FIGURE 4 is a simplified diagram of a conventional vi~ual display element of a pocket electronic calculator.
FIGURE 5 is a simplified vertical cross-section of an embodiment of an electromechanical transducer for a display device according to the invention.
. ~ ~IGURE 6 ghows a circuit diagram of an actuating circuit suitable for the embodiment of FIGURE 5.
FIGURE 7 ~hows in slmplified plan two juxtaposed modules to form two con3ecutive braille character~ from the embodiment~ of ~IGURE 5.
FIGI~E 8 shows a ver-tical sectional view along the line AA' of ~IGU~ 7, The general arrangement oi` the element~ composing an electronic calculator according to the present invention will first be described Thi~ arrangement will be better understood by refering to the diagram of ~IGURE 1.
1a~75~59~
The "heart" of a calculator i9 consti~uted by the arithmetic unit (AU) capable of carryin~ out all the desired operations. This arithme-tic unit i9 a current model used in commercial pocke-t electronic calculatora. The po~sibili-ties o~ the c31cu]Dtor will be ~ hc grent~:r ~a a morc improved aIithmetic unit is u~ed.
By pressing on one or ~everal keys of the kegboard (KB) the braille character corre3ponding to the selected operation i~ composed, The electronic coding circuit ~CO) convert~ this character into a number corre~ponding to the operation selected in the input code of the arithmetic unit (AU), ~he result of the operation supplled by the arithmetic unit (AU) in it~
output code, 19 converted into braille by the decoding circuit (DCO), which sctuates the appearance of the braille figures in relief~on the display panel for the results (DP).
The power supply (PS) i9 of a type currently u~ed in commercial pocket calculators.
An electric calculator according to the present invention, i9 in the form of a rectangular box of small thick-ness, ~ho~e upper surface comprises the di~play panel for the result~ (DP), the actuating keyboard compri~ing the seven key~
(K1) to (K6) and (E) ~nd the on-off ~witch (SW). ~IGURE 2 indicate~ by way of non-limi-ting ex~mple~ a suitable arrange-ment of these element~.
The elements constituting an electronic calculstor according to the pre~ent invention, will now be de~cribed in detailed manner.
KEYBOARD (KB) The ~ix key3 (K1) to (K6) enable the composition of 63 different character~ and consequently the actuation of as m~ny different operations of the calculator. The~e pos~ibilitie~ are ~o~s~
greater than tho~e of the ~ctuating keyboard of commercial pooket electronic calculator~ generally comprising from 20 to 40 key~.
The key (E) la reaerved for the zero rese-t of the calculator.
CO~TNG CI~CU T (~0) Thia circuit i~ ~or convertlng the lnat~uction~ in braille coAe Prom the keyboard (KB) into instructions in the input code of the arithmetic unitD
Such a circuit ia shown, by way of non-limiting eYample, in ~IGURE 3~ The microelectronic components used are currently av~ilable in the trade.
This circult includea a 4-~ay analog switch (C1) actuated by the keya (K1) and (K6) connected to a ten-wsy analog ~witch (C2) actuated b~ the keya (K2), (K3), (K4), and (K5~.
Thi~ arrangement i9 used when the input code of the arithmetic unit is decimsl. The llne~ A~B,C~D ~elected by ~C1) correaponds to the tens, the lines 0~1,2,3,4,5~6,7,8,9 selected by (C2) corre~pond to the unita~ ~he arithmetic unit can thus be given 40 different order~ in decimal cod~, by composing by mean~ of the ~ix keys (K) one of the 40 ~iret braille character00 The ten first braille charactera will corre0pond Por examp~e to the input into the calculator of the ~igure~ ~rom 0 to 9~ the 10 following char~cter~ to 10 operations such a9 addition, subtraction~ multiplication7 divisionD ~tc..., the 10 following characters to the computation order of an operstion - ~uch as inver~ion, squsre~ square root, etc.. ~ and 90 on.
~) In commercial pocket electronic calculator~, the 30 Pigures of the di~play panel oP the results ~re generally conatituted by light-emit~ing diodes or liquid crystal0 com prising 7 rectilinear aegmenta and a decimal polnt according to .
~75i45~
the arrangement of FIGURE 4.
To obtaln the desired flgure lt suffice~ to illuminate the appropriate ~egment~. The ~igure 1, for eYample ~ i9 obtained by illuminating the ~egment~ SB and SC, the figure 3 by illumlnating the aegmenta SA,SB,SC,SD,~G, the minua aign (-) by illumin~ting the aegment SG, etc.,, The ari-thmetic unlts available in the trade are de~igned for thi~ type of diaplay and hence supply the resulta in the correspondlng eight-line code. In an electronic cal-culator according to the preaent inventlon, the decoding cir-cuit is re~ponsible for converting the results into the braille code, A code converte~ oP this type can be, for example, - constructed with a read-only memory of 64 x 6 bit~, DISP~AY PANEL (DP) Each braille character of the display panel for the re~ultg i9 obtained by mean~ of an electromechanical tran~-ducer device according to the present invention of which an embodiment is ~hown in ~igure 5, A cylindrical rod (T) of 1,4 mm diameter can ~lide vertically in two hole 9 pierced in two horizontal plate~ o~ a support housing (H) of molded plsatica material, The upper end of the rod (T) i~ of hemi~pheric ahape ~nd polished ~o a~ to constitute one braille point ln relief ea~y to detect when the rod (T~ extends beyond the upper surface of the ~upport (H) by about 0,7 mm~
The rod (T) i9 fa~tened in a ~mall block of insulating material (P) through which it pa~se~ perpendicularly, e.g.
screwably by a tapping of the block and corre~ponding threading on the rod at lea~t over the axial length of lt~ passage thro~gh the block, with a screwing 310t in either end of the rod~
enabling adju~tment of the projectlon of the rounded end of the rod above the upper aurface of the support ~H), A thin strip 75~5~
or reed of bimorphous piezoelectr~ c ceramic (L) re~ts horizontally in a groove of the block (P) closely ad~acent the rod ~T). This strip i~ gripped at each o~ it~ end~ between two met~llic ~pring~ (R) held inside housings formed in the vertical pillars of the ~upport of molded pl~tic~ materi~l (H)o Block (P) ia located midway between the ends of strlp (L). Two of the spring~
(R) also serve to ensure the electrical connection~ between the upper and lower electrode~ of the ~trip (L) and -the two leads at the respective electric potential~ V1 and V2 (~ee FIGURE 6).
When V1 = V2 the piezoelectric strip (L) i9 rectilinear and ~t re~t. If V1 i~ le~s than V2 the strip t~) curva~ in a vertical plane and pushes the block (P) and hence the rod (~) verticslly upwards. If on the contrary V1 i~ greater than V2 the ~trip (L) curve~ in the opposite direction and pulle the block (P) and the rod (T) verticslly downward~.
~ y u~ing a piezoelectric strip of 70 mm length, 1.7 mm width, and 0.67 mm thickne 99 of lead zirconate-tltanate ~vailable commercially, a verticsl movement of 0.5 mm i~ obtained for a di~ference of 250 volt3 between V1 and V2.
In order to obtsin a very di~tinct retraction or relie~ of the braille point it is desirable to have an overall travel of the rod (T) of about 1 mm, Stop mesn~ can be provi-ded on the rod to limit e~ces~ive bending of the piezoelectric strip which msy break it, through e~ternal pres~ure on -the end of the rod. The~e ~top me~ns may be con~tituted by the threading on the rod forming ~houlders which can come into abutment with the edges of the holes in the hori~ontal plates of the hou~ing (H). Said travsl can be obtained by using the actuating circuit ~hown in FIGURE 6.
3o Thls circuit compris~ two high-voltage tran~istors (TR1) and (TR2), two losd resi~tor~ (R13 and (R2) of which ~
typicsl v~lue i~ 22Q 9 t~o re~istor~ in the ba~e circuit~ of the tran3i~tors (R3) and (R4) of which a typical v~lue i~ 470 kQ
and a digital inverter ~I) An electrlcal control voltage Vc ie applied at the point indlcated in the dia~r~m of ~IGURE 6. Thia voltage i~
~uppll~d by the decodin~ oircult (DaO) de~cribed previoualy.
A po~itive voltage Vc renders the tran~i~tor (TR1) conductive and blocks the tran~istor (TR2) One then obtain~
V1 = and V2 = 250 volt~ for ~ supply voltage V~ of 250 volts.
A zero voltage Vc produces the reverse re~ult, tha-t i~ to say V1 -- 250 volts and V2 = 0 The de~ired vertical travel of 1 mm for the rod (T) i9 thus obtained.
T~o of the principal advantage 9 of the braille point di~play device according to the presen~ invention are:
1) Very low electrioal consumption: about 3mW for the circuit described. Thi~ consumption i~ le~s -than thst of a luminous ~egment.
2) S~all ~ize permitting the ~uxtaposition of a~
many braille character~ as de~ired whilst re~pecting the ~tandsrd dimen~ion~ ~nd spacing o~ br~ille oharacter~.
20 ! According to the present invention, this ~uxtaposition i~ produced by arrsnged 12 piezoelectric strips in 4 ~et~ o~
three, two of ~aid set~ with their respective ~et of 3 block~
(P) being one above the other in the ~pace ~v~ilable between two consecutive braille characters. Each rod in a ~et o~ three i~ couplcd to its re~pective block only and passe~ freely through hole~ in each of the other bloc~s in the set. This - arrangement i9 ~hown in Figures 7 and 8 which ~how respectively 8 plan ~ie~ ~nd a vertical sectional view along AA' of the group of rods (T) snd of the strip0 (L) constituting a group of two consecutive braille charac~er~ ~or the left-hand character, the strips de~ignated by the letter~ a,b9c,d9e7f respectively drive the rodq de~ign0ted by the figures 1,2,3,4~5,6.
_g_ ~7~5~
Up to -twelYe rod~ (T) and the correaponding ~trip~ (L) can be housed in one modular support of molded pla~tics material as disgr~mmatically sho~n in ~'igures 5,7 and 8.
T~o adjacent modular supports ~andwich a printed circult board on which the requisite elements are mounted according to the circuit diagram of ~IGUlæ 6~ for producing -the electrical actuation of the movement of each of the twelve rod~ (T) in one modular support.
A mod~lar ~upport with a printed circui-t board con-~titute 9 a module of one half~ one complete and one half braillecharacters. The dimensions of such a module are typically 12 mm in width, 40 mm in heightl and 140 mm in lengthO A display panel with 2N braille characters i9 produced by juxtaposing N modules.
Thu~ the braille read-out panel can conveniently hsve a line of ~even ~uch module~ sandwiching ~ix printed circuit board~. The last module may carry al90 two short hori~ontal met~l tablet~ -placed later~lly to the line of braille - forming an electrical ~witch for triggering or ch~nging the braille display when contacted by the finger or for memory tran~fer. ~hese tab~et~
are connected to the electrical circult in manner known in itsel~.
A braille read-out panel ~ccording to the pre~ent invention places at the dispo~al of the blind the immen~e present ~nd future po~sibilitie~ of electronic pocket calcu-lator~ whil~t pre~erving all their advantag~s5 small bulk, lightnes~, silent operation, ~ev0ral hour~ of autonomou~
operation by means of incorporated batterie~. Thi~ applie~
natur~lly to o~ice electronic calcula-tors or to large electronic calculator~.
Be~ides its use in electronic calculatcr~ a braille read-out panel sccording to the pre~ent in~ention may be in~
corporated in other reading and recording equipment intended for the blind, e.g. for recording and read-out of magnetic tape $~
or punched tape, e~pecially a portable "minica~set-te" player.
The device could also be used in equipment for controlling machines ~nd tran~mi~ion of data or of order~ to a distance, where monitoring in braille or the like can replace vi8ual monitoring.
The device according -to the invention could obvlously be u~ed to di~play a code other than br~ille compri~ing a differ~nt number of relief point~ than siY or a different geometric arrangement of the points.
Although the foregoing de~cription and drawing~ relste to ~pecific embodiment~, it will be understood -that various modifications may be made without departing from the ~cope snd spirit of the invention, as defined in the appended cl~im~.
many braille character~ as de~ired whilst re~pecting the ~tandsrd dimen~ion~ ~nd spacing o~ br~ille oharacter~.
20 ! According to the present invention, this ~uxtaposition i~ produced by arrsnged 12 piezoelectric strips in 4 ~et~ o~
three, two of ~aid set~ with their respective ~et of 3 block~
(P) being one above the other in the ~pace ~v~ilable between two consecutive braille characters. Each rod in a ~et o~ three i~ couplcd to its re~pective block only and passe~ freely through hole~ in each of the other bloc~s in the set. This - arrangement i9 ~hown in Figures 7 and 8 which ~how respectively 8 plan ~ie~ ~nd a vertical sectional view along AA' of the group of rods (T) snd of the strip0 (L) constituting a group of two consecutive braille charac~er~ ~or the left-hand character, the strips de~ignated by the letter~ a,b9c,d9e7f respectively drive the rodq de~ign0ted by the figures 1,2,3,4~5,6.
_g_ ~7~5~
Up to -twelYe rod~ (T) and the correaponding ~trip~ (L) can be housed in one modular support of molded pla~tics material as disgr~mmatically sho~n in ~'igures 5,7 and 8.
T~o adjacent modular supports ~andwich a printed circult board on which the requisite elements are mounted according to the circuit diagram of ~IGUlæ 6~ for producing -the electrical actuation of the movement of each of the twelve rod~ (T) in one modular support.
A mod~lar ~upport with a printed circui-t board con-~titute 9 a module of one half~ one complete and one half braillecharacters. The dimensions of such a module are typically 12 mm in width, 40 mm in heightl and 140 mm in lengthO A display panel with 2N braille characters i9 produced by juxtaposing N modules.
Thu~ the braille read-out panel can conveniently hsve a line of ~even ~uch module~ sandwiching ~ix printed circuit board~. The last module may carry al90 two short hori~ontal met~l tablet~ -placed later~lly to the line of braille - forming an electrical ~witch for triggering or ch~nging the braille display when contacted by the finger or for memory tran~fer. ~hese tab~et~
are connected to the electrical circult in manner known in itsel~.
A braille read-out panel ~ccording to the pre~ent invention places at the dispo~al of the blind the immen~e present ~nd future po~sibilitie~ of electronic pocket calcu-lator~ whil~t pre~erving all their advantag~s5 small bulk, lightnes~, silent operation, ~ev0ral hour~ of autonomou~
operation by means of incorporated batterie~. Thi~ applie~
natur~lly to o~ice electronic calcula-tors or to large electronic calculator~.
Be~ides its use in electronic calculatcr~ a braille read-out panel sccording to the pre~ent in~ention may be in~
corporated in other reading and recording equipment intended for the blind, e.g. for recording and read-out of magnetic tape $~
or punched tape, e~pecially a portable "minica~set-te" player.
The device could also be used in equipment for controlling machines ~nd tran~mi~ion of data or of order~ to a distance, where monitoring in braille or the like can replace vi8ual monitoring.
The device according -to the invention could obvlously be u~ed to di~play a code other than br~ille compri~ing a differ~nt number of relief point~ than siY or a different geometric arrangement of the points.
Although the foregoing de~cription and drawing~ relste to ~pecific embodiment~, it will be understood -that various modifications may be made without departing from the ~cope snd spirit of the invention, as defined in the appended cl~im~.
Claims (20)
1. An electromechanical transducer device comprising:
a bimorphous piezoelectric reed bendable around an axis perpendicular to the longitudinal axis of the reed on the appli-cation of a DC voltage;
support means for each end of said reed;
coupling means supported on said reed;
a rod arranged transversely to said piezoelectric reed and coupled to said coupling means;
and means for applying a DC voltage to said reed;
whereby on the application of said voltage the bending of the reed causes static displacement of said rod in the direction of its own longitudinal axis.
a bimorphous piezoelectric reed bendable around an axis perpendicular to the longitudinal axis of the reed on the appli-cation of a DC voltage;
support means for each end of said reed;
coupling means supported on said reed;
a rod arranged transversely to said piezoelectric reed and coupled to said coupling means;
and means for applying a DC voltage to said reed;
whereby on the application of said voltage the bending of the reed causes static displacement of said rod in the direction of its own longitudinal axis.
2. An electromechanical transducer device according to claim 1, wherein said coupling means is symmetrically located midway between the two ends of the read.
3. A relief display device module comprising: a sup-port housing including a tactually scanable plate having a plurality of holes therethrough arranged in an array; a plurality of electromechanical transducer devices housed in said housing, each electromechanical transducer device comprising a bimorphous piezoelectric reed bendable around an axis perpendicular to the longitudinal axis of the reed on the application of a D.C.
voltage, support means for each end of said reed, coupling means supported on said reed, and a rod arranged transversely to said piezoelectric reed and coupled to said coupling means, said rod having an end traversing slidably a respective, corresponding one of said holes between a first static position in which said rod end projects a tactually detectable distance from its hole and a second static position in which said rod end does not project from its hole, by the application of a D.C. voltage to said reed; and a printed circuit adapted to be held against said hous-ing, bearing a plurality of electrical actuating circuits for the respective piezoelectric reeds.
voltage, support means for each end of said reed, coupling means supported on said reed, and a rod arranged transversely to said piezoelectric reed and coupled to said coupling means, said rod having an end traversing slidably a respective, corresponding one of said holes between a first static position in which said rod end projects a tactually detectable distance from its hole and a second static position in which said rod end does not project from its hole, by the application of a D.C. voltage to said reed; and a printed circuit adapted to be held against said hous-ing, bearing a plurality of electrical actuating circuits for the respective piezoelectric reeds.
4. A relief display device comprising a plurality of modules according to claim 3, assembled together in juxtaposition so that the scanable plates form a continuous planar surface.
5. A relief display device comprising :
a tactually scanable plate having a plurality of holes therethrough arranged in an array ;
a plurality of rods having corresponding ends travers-ing slidably said holes ;
a plurality of bimorphous piezoelectric reeds having electrodes and bendable longitudinally on the application of a DC voltage arranged on one side of said plate;
means for supporting the ends of said reeds and means for electrical connection to electrodes of said reeds ;
rod-coupling means supported on each said reed and coupled to a rod to hold it perpendicular to a respective one of said reeds, each rod being movable along its longitudinal axis between a first static position in which its said end projects a tactually detectable distance from its hole and a second static position in which its said end does not project from its hole, by the application of a DC voltage to its respective reed.
a tactually scanable plate having a plurality of holes therethrough arranged in an array ;
a plurality of rods having corresponding ends travers-ing slidably said holes ;
a plurality of bimorphous piezoelectric reeds having electrodes and bendable longitudinally on the application of a DC voltage arranged on one side of said plate;
means for supporting the ends of said reeds and means for electrical connection to electrodes of said reeds ;
rod-coupling means supported on each said reed and coupled to a rod to hold it perpendicular to a respective one of said reeds, each rod being movable along its longitudinal axis between a first static position in which its said end projects a tactually detectable distance from its hole and a second static position in which its said end does not project from its hole, by the application of a DC voltage to its respective reed.
6. Relief display device, comprising a reading plate having an array of holes arranged perpendicularly therethrough, an array of rods slidably arranged to project one end selectively through said holes, a plurality of multimorphous piezoelectric reeds, means coupling each reed to a respective rod, means con-necting each piezoelectric reed to a source of electric voltage, means for controlling said voltage at one or the other of two distinct values as a function of an electrical control signal, and coding means supplying said electrical control signal where-by the piezoelectric reed bends in one directions or the other so as to cause the rods selectively to retract or project on the reading plate.
7. Device according to claim 3, wherein each said coupling means comprises adjusting means for the amount of said projection of the end of the rod beyond said hole.
8. Device according to claim 7, wherein said adjust-ing means comprises a threading on the rod and a taping in the coupling means.
9. Device to claim 3, wherein said rods are arranged in groups of six so that the ends of the rods from the conven-tional pattern of dots of a braille character.
10. Device according to claim 9, wherein said piezo-electric reeds are arranged between the aforesaid groups of rods and parallel to the reading plate and to the largest dimension of the braille character.
11. Device according to claim 1, including limiting means for the longitudinal axial movement of the rod, to avoid excessive external pressure on an end of the rod from bending the reed associated therewith beyond its breaking threshold.
12. Device according to claim 11, wherein said limit-ing means is consituted by a shoulder on the rod arrestable by the edge of an apertured element traversed by the end of the rod.
13. Device according to claim 1, wherein said support means for the ends of the reeds and said DC voltage applying means are constituted by metal spring strips fixed in notches, in an insulating housing.
14. A relief display device according to claim 3, in-cluding a metal touch switch adjacent to the scanable plate for changing or transferring the displayed data.
15. A pocket electronic computer comprising a relief display device according to claim 3.
16. An apparatus control panel comprising a braille keyboard and a display device according to claim 3.
17. In an information processing device, an electro-mechanical transducer according to claim 1.
18. A portable minicassette magnetic tape player/
recorder comprising in combination: a braille keyboard; a tape transport unit; a control circuit and a relief display device which comprises:
a support housing including a tactually scanable plate having a plurality of holes therethrough arranged in an array;
a plurality of electromechanical transducer devices housed in said housing, each electromechanical transducer device comprising a bimorphous piezoelectric reed bendable around an axis perpen-dicular to the longitudinal axis of the reed on the application of a D.C. voltage, support means for each end of said reed, coupling means supported on said reed, and a rod arranged trans-versely to said piezoelectric reed and coupled to said coupling means, said rod having an end traversing slidably a respective corresponding one of said holes between a first static position in which said rod end projects a tactually detectable distance from its hole and a second static position in which said rod end does not projection from its hole, by the application of a D.C.
voltage to said reed ;
a printed circuit adapted to be held against said housing, bearing a plurality of electrical actuating circuits for the respective piezoelectric reeds; and a metal touch switch adjacent to the scanable plate for changing or transferring the displayed data.
recorder comprising in combination: a braille keyboard; a tape transport unit; a control circuit and a relief display device which comprises:
a support housing including a tactually scanable plate having a plurality of holes therethrough arranged in an array;
a plurality of electromechanical transducer devices housed in said housing, each electromechanical transducer device comprising a bimorphous piezoelectric reed bendable around an axis perpen-dicular to the longitudinal axis of the reed on the application of a D.C. voltage, support means for each end of said reed, coupling means supported on said reed, and a rod arranged trans-versely to said piezoelectric reed and coupled to said coupling means, said rod having an end traversing slidably a respective corresponding one of said holes between a first static position in which said rod end projects a tactually detectable distance from its hole and a second static position in which said rod end does not projection from its hole, by the application of a D.C.
voltage to said reed ;
a printed circuit adapted to be held against said housing, bearing a plurality of electrical actuating circuits for the respective piezoelectric reeds; and a metal touch switch adjacent to the scanable plate for changing or transferring the displayed data.
19. Device according to claim 13, wherein each end of the reed is slidably gripped between two of said metal spring strips.
20. Device according to claim 9, wherein said coupling means defines holes therein for the free passage of the rods adjacent to the coupled rod.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA258,505A CA1075459A (en) | 1976-08-05 | 1976-08-05 | Electromechanical transducer for relief display panel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA258,505A CA1075459A (en) | 1976-08-05 | 1976-08-05 | Electromechanical transducer for relief display panel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1075459A true CA1075459A (en) | 1980-04-15 |
Family
ID=4106587
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA258,505A Expired CA1075459A (en) | 1976-08-05 | 1976-08-05 | Electromechanical transducer for relief display panel |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1075459A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6230139B1 (en) | 1997-12-23 | 2001-05-08 | Elmer H. Hara | Tactile and visual hearing aids utilizing sonogram pattern recognition |
| CN111462592A (en) * | 2020-05-09 | 2020-07-28 | 长春大学 | Piezoelectric elastic sheet type braille point display device |
-
1976
- 1976-08-05 CA CA258,505A patent/CA1075459A/en not_active Expired
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6230139B1 (en) | 1997-12-23 | 2001-05-08 | Elmer H. Hara | Tactile and visual hearing aids utilizing sonogram pattern recognition |
| US6351732B2 (en) | 1997-12-23 | 2002-02-26 | Elmer H. Hara | Tactile and visual hearing aids utilizing sonogram pattern |
| CN111462592A (en) * | 2020-05-09 | 2020-07-28 | 长春大学 | Piezoelectric elastic sheet type braille point display device |
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