DE2164202C3 - Pressure actuation sensitive signaling device - Google Patents

Description

The invention relates to a pressure actuation sensitive Signaling device with one component

ίο and a conductive counter electrode that is connected to a Electret provided with metallization layer sections have and face each other at a distance, the electrical properties of the conductive Counter electrode and the component relative to each other

other when a pressure is exerted in such a way that the counter electrode and the component approach one another, to be changed.

Basic demands that are made of improved Druckbeiätigunt ^ selection devices.

lie in the simplification of their mechanical house, the elimination of metal contacts and de; Improve reliability. Furthermore, the Dimensions are reduced, the sensitivity is improved, the manufacturing costs are reduced and the Fr. generation of an output signal are enabled because can be used without additional monitoring or processing.

A large number of signaling processes crfo; - the generation of voltage pulses or tone signals according to a prescribed code. For example, in the known Telefonappar.iteu voter arrangements are used in which Metallkun takle operated to interrupt a power source in the formation of sequences of binary pulses

the. On modern telephones, print dialers are used used to form mechanical circuits which trigger the creation of multi-tone signals Push button switches are of additional importance ;; as input devices for electronic calculating machines and the like.

As with all mechanical switch trainingc ohmic contacts occasionally become contaminated and then fail. It is even more important that mechanical Arrangements are relatively heavy and bulky.

have high inertia and, because of the precision required to manufacture them, significant over the total cost of signals;. contribute to their arrangement.

In order to avoid the continuing difficulties of mechanical dial or pressure dial selectors, a large number of alternative switch designs have been developed. z. B. Junction point matrices and magnetic and electrostatic healing developed. For example, the clamp of an actuator can be replaced by a single layer of flexible material which covers a matrix arrangement of conductors. When the resilient cover sheet is pressed at defined points, a corresponding ohmic contact is established by bringing the conductors underneath into contact with one another. 111 Siunalgabexorrichungen constructed in a similar manner with pressure-sensitive electrostatic elements, as described for example in the ISA patent 3,281,541, avoid a number of difficulties inherent in mechanical components.

In a typical electrostatic unit, a change in capacity / wipe of a printing plate and a reference electrode, which as a result

l, s heating of a finger on the plate er / cugi dung-like signaling crdir rpf.ehli ej>

drd al-eetastet and to generate ernes wciieiver- each other, the electret at discrete, essentially with ue

operable signal is used. Such eleltrosiatb.chcn associated counter-electrode aligned positions

, "Α i",; niart! I! En membranes using units to polarize one of the two polarities,

Although compact, they require any help.

ir the excitation and sampling and signal generation - provided that two over one another "^^^

»Information on the generation of suitable columns. step foils with metallized, von den tieg <-

Fs jM a sisnal statement of the single ·. er the alternate surface sections and u

"Uhmen type suggested (German OfrenlegWs- locking devices for \ Veiterle.tungderdurcnn-i, _ thrift ■> K'5 071), in which the charge function

W from "wax, resin, fluorocarbr. Nsd.rehien or Irish properties to an external Scnaliun χ t r-

itankcramik built up electricity are used. In the connection devices kor, run

L _n by a case wi- by changing the kapimuh ₇ delay units for verzcgenen

Crhen a -arched spring and the upper surface of the eabe of the individual signals can be provided. -AuLerα

Flekl-ct in "fast approaching the spring _of that. ₅ can also Summauonsemr.chtun ^ s <iu about

Fleitrc '' «^ S ^les electrical signal ai,. ^: .ncr da- Association of delayed signals of certain construction

visclie · lying target plate is removed. The elements with the other signals for approval

Judgments approximation of the spring to the Or-einäcl-.e de- composite signal should be provided.

> lct on the basis of a signal issued via TaMer.diuck. rnch

^ ■ l-nap of the leather. Xr ^ dun da- 20 tunaen according to the invention, st a V lelzani ^ π

Such springs in Alte.uns- / 1, fractures of separate conductive components in em _e

- Is there a disadvantage of this Siünalüabevorrich- desired pattern in an insulating body angci ■ _

"all in the use d ', - r wrge-el c., -n The entirety of these components is of a ύ unnc

: _{K; l} cr, alien, since the ^ e their Poiari.aii .-. Rs.-ice. ·, Metallized electret foil or «""/'^'"'jen

, “1 change forever. ·.,.:, D. _; , u h \ bn = 5 1 olien covered, which at a short distance of

! Functional safety of the bck.ü-.ntcn \ rnidi components and held together sinü. " _P

"Hi over longer periods of time i ^ älMk-io.ei i> t. Fine example white with openings from umercit ..

provided front cover is in St.

derknownNMnchM ,,, ^ ,,, ^ ,,,! - ν seen ν ordere Abg

by \ ending ccr! ^, rdcen nie.alli.chen. conductive structures, len ^ J ^ ^ en one of the applicants-, ennskkcltcn so slide reiaiiN _? u one of these building blocks, thin-layer membrane - mutier .. Soki shifted "ird. w, rd em sign ahm uk en α, cd., "ere membrane or lohe w,:, generated as a closed output current circuit. DaUi

r-olie and. if the slide with he, ■ dimr.en. Learn H.Usdetektor required. _Auxiliary .

e: - Coating on one of their Ol-c! ! IaL! En χ - The signal is therefore sufficient for actuation

Ν ,, generally tls .Metallfolien-1 lecture- .der 35 os.illatoven. Switch elements Ve sta Urn od ^ el »Metallized electret * beehre ,. 1 ick- off. The E ^ ndungsgema D uckh κ. * ^

k f ^ h each eJAu c a

Sch Ms »Metallized electret * beehre ,. 1 ick- off. The e ^ ndungsgem ^

_{tc di} , .cr Art have a permanent load. the device can be used for ν ^ ch every eJAu c ag

close, change, uul «ground, even over longer periods of time, in order to sr, 7u.llu Λ ^ nUu. , ^^

develop when they are in waiulleramgem A.Mb.u ve.- sen. So can be ^ ₁ ^ ^ '^^ _{ld dcr mil} OfT-

_W end, are in shift, "- arc ^ ang, '" -. ^^^ f ^ l ^ U ^ be.

ehend from a Signalgahc ^ rUHun, d, r to> s J leUre,

vs mentioned kind becomes this, Ιλ,, -: imdm ^ sge- Schaoen by Handl -.

Sso.ehergcHldet.daßdasBaueicn ^ duuhXV, - S.hiuic η / u se ζ «ΐ * η Jj ^^ elgsperso

_WC ndung a loaded F.lck.rci-1 «lie m.tweiv.Mens, 5 as intermediate; enfl.« LI.t> ^ en emc ^^^

a Metallisierungssch.cluabschnu, aK! hurrying and the lektict.oh, he cn κ, ■ Flektrct-

SSnbran is trained. wöbe, die Dicke de, llektre,, ünsch, ~ -r. ige c ^ - ^; " _{p | aUe}

FoHeundihrAbs.andvonderleiRndcnGegcnekk.rode loh en /w.scUn er m, UH ι μ _Gel , _cnclcklr oden

_The decrease is that the device is being used against others or against others

bs.andg _gel , _cnclcklr oden

abccN 'are that the device against others or uer Scln.t / now bian ιJ ü ac ^

Druckbetäligungskrätze im. and that 50 earths arranged one above the other around impuL t hib d Fkk1lien posa.xer and neg at κ r I oUr iu t / u ^ ^

£ Implicit in printing pressures. and that 50 are on top of each other

^ directions no shift of the Fk-ktret-1-olien posa.xer and neg at κ r I oUr iu t / u ^ ^ « _la , iv, ur conductive counter electrode through Aulbnn- Impj. sfobjen konnu Ad ^ eb solution of external pressure release claw are Norgeschen. Connections from Aiisemu ..

, "A preferred further development of the r.ründinig" "the arrangement of the used

id Eiihten for the local delimitation of the meg 55 L na Mnii tιμ vi ⁿ 'J iktDckbc

, "A preferred u g ^ arrangement of the used

are facilities for the local limitation of the meg 55 L na Mnii tιμ vi ⁿ 'J _äßc picktrct-Druckbc-

i äP dc l-.lektrei- Baute, e is d ^ e. * ^s ^ ^ _fh

are facilities. J _äßc picktrctDru

wedge of the installation of an outer. dc l-.lektrei- Baute, e is d ^ e. * ^s ^ ^ _{11 com lct} . _simple

Foil shifting Druckbetäi.gungskrali sorge- tatigurgsv al lonich «« "6« ■ typical for the

see. Dice limiting devices, earth ent- to ergan / eu, d to c las ^ J ^ _{fflr cin T} ele-

_W eder of an apertured de ^> ^ ^"d" ^ t See SchcibcnwäWers besti

Elektrct-Folic covering Dcck _r 'is formed atte. 6c o, a, StclIc d, s ^ e _{d of}

^^^^ ΆΤΙΆ ^ --ndd ^ gärachteKi-aftinderG ,,, n _g

_z “stir up, it is advisable to use one of the riektrel-lolien 6 ₅ u, - 10 cl> -n lag _{p lksch} , _T , _hu , _lg

covering, uncharged and yielding S.hu / - D l .1 In.du, ^ j, ^ _Vcrbnuh ,, " _g " n. de

film to be provided. When arranging several components rr.chκ u Λ ■! ■ nt _; ^ / "Bill / cgt

ments and related, r.cgcnclekirode m of the crl.n- attribution near crlautcii.

Fig. 1 is an exploded view of the basic components one according to the invention, sensitive to pressure exposure Dialing device,

F i g. 2 is a sectional view of the basic structure a call dialing device according to the invention, in which a protective film and push button guide members are used

F i g. 3 an embodiment according to the invention, in which has a plurality of individual metal foil electrets for generating coded pulse trains different polarities are used,

F i g. 4 shows a trapezoidal displacement of the film of an electret selection device according to the invention and the resulting voltage pulse of the unit for two different time constants and

F i g. Figure 5 shows the voltage of one unit of an electret pressure sensitive dialer according to the present invention as a function of the force exerted for various connection resistances.

F i g. 1 shows, in a view taken apart for explanatory purposes, the main parts of a pressure-actuation-sensitive dialing device according to the invention. The dialing device includes a plurality of conductive _{gear electrodes 11 o} ... ι I _n embedded in an insulating support member 12. The counter electrodes 11 are preferably set back by a small amount behind the front surface of the holding component 12. In a typical embodiment used in practice, each counter electrode 11 has a diameter of about 1.6 cm, and the holding component 12 is made of an insulating plastic material. The counter electrodes are set back in this ym Ausfünrungsbeispiel by about 50 in the insulator.

If desired, the individual counter electrodes can be made conductive as printed on a circuit board Be formed surfaces. When the conductive sections are applied to the surface of the sound board an apertured insulating layer is used to form the required dislocations used. On the other hand, the conductive counter electrodes can also be deposited in recesses in the circuit board.

A film of a metallized electret painting 13 is placed over the counter electrodes and rests essentially on the surface of the mounting component 12. In an example carried out in practice, an electret film was made from a single 51 μνη thin film of polyfluoroethylene propylene plastic material (under the Trade mark “Teflon FEP”) with a 1000 Å thick metal layer 13c (Fig. 2) on one of its surfaces. After polarization, such an electret film usually shows a charge of about 10 ~ ⁸ C / cmA

The metal foil electret 13 is of a thin cover plate 14 with a plurality of with the conductive counter electrodes H _n -. 11 » ₍ in the holder 12 in the open openings IS _n ... 15 _{n held} in its position. In this embodiment, the metal layer on the foil 13 faces the cover plate 14. If desired, the cover plate 14 can be made of conductive material The cover plate is attached, for example, to a conductive housing 16 which encloses the insulating holding component 12. Each counter-electrode II is connected to a connection 17 ". The other electrical connection (not shown) is made to the metal layer 13c on the foil 13. If the cover plate 14 is lciteud and if no further auxiliary layers are used, the connection can be made to the cover plate 14. Obviously, other types of mounting can also be used be used.

The selector mechanism is activated by briefly pressing one of the exposed film sections actuated by one of the openings 15 in the cover plate 14. After the release of the film, it reverses as a result their tension and stiffness back to their rest position. As a result of this type of actuation, the foil electret work 13 and the opposite electrode as an electromechanical converter - im In contrast to an electroacoustic transducer - - and generate a voltage pulse v (r) on one between the metallic surface 13c of the electret 13 and the common electrode terminal 17 switched impedance.

The voltage pulse generated can be described by one of the following two relationships will:

v (i) = j (0 ad)

Here s (t) means the mean (spatial) displacement of the foil electret, s (t) the derivative of s (t) with respect to time, and /; (/) and a (l) are the unit impulse and unit step responses, respectively on the shift. The selection device can thus be viewed as a circuit which comprises a series connection of the capacitance C of one of the electret transducers (foil 13 and counter electrode 11), a connection resistor R (not shown) and a voltage source which is responsible for the voltage generated by the electret transducer. This circuit is characterized by:

= At> d) - ^A e- "« ^i? For r> 0

Rc -

= 0 t <0

a (t) = / Ie- ' ^Rr door r> 0 = 0 / <0

Here f) (i) is the Dirac function, and A is the ratio of the voltage generated by the voltage source c to the mean displacement of the foil electret. So A is given by

A ^

In equation (5), σ is the effective surface! Charge density of the electret on its non-metallic surface, D and f / are the thicknesses of the electret or the air layer / "wipe the electret 13 and d <counter electrode 11, f is the dielectric constant of the electret material, and F ₀ is the dielectric constant of the free space. Equation (5) gi if the displacement s (t) is considerably smaller than d gap d .

As an example, the voltage v (/) for the trap (

kind
_thru

Displacement function according to FIG. 4a given

s (l) (sj. \ t) (I ₂ i ') for - ι.,

- i \

~ _v

I ') (h -

Druckbeläligung in the order of 0.3 to
Measured above 20 V, these values depending on the connection resistance and the force exerted. In the
output voltage developed in a typical unit
is in Fig. 5 plotted as a function of the force exerted. Although the output voltage at small
Power levels as power increases, it becomes higher
Krafinivcaus regardless of this. This is upon it
to return that the rise time of the shift of the rise time of the io function .1 / is considerably smaller than the time constant of the

(6)

the voltage ι (ί) at K

Y (I) /f[.s'(Ä)

U,

^{(f /) ΚΙ} '<Ιλ.

, 4,

U)

and a-

ίο ",

Signal voltages of this type can be generated directly without further acquisition and often without additional processing be used. The generated signal can, for example, be sent directly to an amplifier circuit

By calculations. ^ U CW set the obtained value m oicienung ν, _b t

y (t) Δι As ₀ RC

suitably high input impedance can be applied. b ^ ^ ^ _{ejn grading} . _FeldefTekl .

transistor amplifier a suitable input

- 0 door t

_ _e

I. <l

I _I ■ ι

ι '

_c i. in

- ((, ι-si nc

^1C T ϊϊ

, v

for RC 0 1 /., and

management element is. Alternatively, the output signals can be amplified in each bipolar transistor amplifier beispiclsNveisc a multi-stage amplifier to achieve the required input impedance with negative feedback can be used.

An alternative design that is used during manufacture A selector switch according to the invention can be used is shown schematically in FIG. 2 shown. The structure shown here in cross section is consistent with the device according to FIG. 1 over, with the exception that an uncharged, thin and resilient auxiliary film 18 wipes uas film flekiret 13 and the apertured cover plate 14 is inserted. It is often desirable to have such a helper to protect the foil leakage against environmental influences or other damage and to ensure maintenance-free operation. the

wor eme '^^' (»dilTerenzierte,), from two needle word cine xcr / c y displacement is,

Impulses existing WuJc "gsfunkt.on

while for RL ■ ■ · "^;

l "

KL · - lu λ, plotted in Hgurcn4b and 4c, respectively. l ^: .s

it was assumed that * jß ^ ^ ⁹ / *, ^ ™ J _am " ₄₀ ,, _{olic 18 isl} preferably with the housing 16 (F, g. 1)

connected to maximum protection for the dialer to reach.

In some cases it may also be desirable to have shaped push buttons or the like to facilitate actuation

can be seen to be used with an as of the unit. Since pushbuttons generally 'sMetal foil strips are used, they give the unit a more conventional one Look. However, it is more important that pressure loads or other mechanical actuation are used members are used to ensure a more even displacement of the electrical circuit. In the drawing, dii Push buttons 19 have a concave surface shape and are held in openings in plate 14. The push buttons or push-button shape and its dimensions is only a question of the design chosen. Whom if they are pressed down, they effect the necessary

Agi ordered at a Anschlußaus a pair "of Nadclimpulscn corresponds · _{rilät mjt DCR} Zeilkonstanten of gegcngcsctzie '^ periods when the

Systems vcrg lil1. Shipping time is

Pl 7H, ^S Santcn who are bigger, isl duTeleklnschc ^hurZcilk "ähd li

approximately equal to the displacement Da the output voltage of the unit from Ργλ li.ki Hos field in the air gap between the foil and

irodUMoi-si ^ ^ _{i] cr Vcrsc} , _iicr , _{ung of} the displacements of the 1 lekircts 13 relative to the opposite

der ^ ucgcnciL _h ., ^ ρ, τ ^ j _s t, should be the size of electrode II and generate an output signal. Durc

Foil in the ^ ^ for example by the Ticfa suitable adaptation of the length of the extension _{component 12 given by the ÖITnun des Luitspa., N-, | t C} , a recess 11 · ^ | - _o | _{jc | rarnclcrn uru} l the impact effectgesidicrl, which are physically possible

Prevents destruction of the foils. The flexible foils are generally elastic enough, ui Return the pushbuttons to their inoperative position, but it may be desirable to use the following help:

I ^ order of magnitude of the film thickness suitable to use 65 feathers. If necessary, (nid 'shown) auxiliary devices are used, the ai

_{mll Ullltl} ^. ".." _Ι16 ... show that contact is made. For example, could

^lni p, ^e _m \ '"mrrinn 1 mmilsamplitudcn as a result of the finger openings or the pushbuttons belcuchl

kcilvon
nangigK_ _h

waited iron

w
d

cnparamc

be elected. If the di

_h g

waited iron ^ the field is sparse; if the

Recess to g » ^ - ^ j _st the shift be-recess to _fundcl1 'that a gauging

limits the _{thickness of the} oil suitably iicte in

.-,,. . _m j ₍ a leakage density of were pulse amplitudes due to

when contact is made or becomes audible. This signal is used in the delay pre-

or other visible indication that delays the operator 24 so that it is at c.ncm by Cc time.

Srsondic contact indication «is provided. duration, / compared to the first nipuls shift, η

This means that display elements are known to the laughing man at the time of release. In the ^ hegenden Bcisp ^ m-

and include elements such as buzzer, "cnckcU" assumption that both ions have the same bottom line

c tunKen and analog or digital display windows. so that two posil.vc pulses are generated. If de

πίAnnen in a suitable toilet arranged electrical foils both negative or bump positive H «" _S. = r. smd

Irish contacts between a section of a are time-shifted impulses of the same Polantat

Press button ζ B 19 and connecting a printed one generated. If one is positive and the other is positive

Sdriltunu 'on the auxiliary film 18 or in isolated η is negative, pulses of opposite I ο antat

Channels of the cover plate 14 are used. generated. Alternatively, the delay device

As a further aid, which a desired 24, for example in the film 20 with the summa-

Allows switching sequence, suitable identification device 23 can connect. Communication

marks can be arranged in connection with each selector switch position. Bc _{1 of} this solution can be used between. For example, suitable 15 of the film 13 and the C.cgcnclckirodc 11 developed

Position indicator !! on the outward signal in front of the between the lohe 20 and the lciien-

Surface of the film at the point of each opening on the layer of film 13 generated signal occur.

prints or attached individually. If the auxiliary can be evidently by suitable choice of the pole

Protective film is used, the identification marks of the 1 olien-electret layers and the Anzuesvveisc arranged under the protective layer. If 20 order and the 7 number of delay units each

Pushbuttons are used, the Stcllenkcnn- desired pulse sequence onliguralion is generated.

drawing preferably in the usual way in the key case- If desired, this can be between cmc- fohen-

r -inncorders electret and the conductive layer of the andcci ι ick-

^P in Fig. 3 a further embodiment is shown schematically a signal generated by an output note of the invention, in which multiple »5 leads are generated, which are independent of the output signal.

Folicn from Elcktretmalcrial for the production of a lung is. which the \ on a foil electret ^; Jer

Pulse sequence of positive or negative polarity for each associated counter electrode at the same point ail-

Shift are used. In the drawing are wrapped signal received.

two foils 13 and 20 over each individual counter- As an elekiret-folic on individual voneinaiuie gcelektrodc 11, with the two metal separated points being polarized in opposite directions iwiin,

layers 13f and 2Or facing away from the electrode. can the specified on the respective actuation stcllc - approx.

A small air gap 21 is created between the foil netc Ahse-hiiiu de ·! Ϊ lcktrei foil either positive .'der

layers, for example, be negatively polarized by insulating spacers. That with every actuation > -. \\ c

siü-ke 22 maintained. The spacers 22 developed signal is accordingly ■ -er can be in the form of single insulators, but 35 coded polarity. Hei use of more .h-

can also have a lattice-like configuration or a foil patch. - be it with or without counter eleki. -'eic,

apertured plate of insulating material can be attached to each actuation slide.

verv. ends, the openings of which are applied with the counter-codings. Those of the ve; ^ '-c-

clc'ktroden 11 align. On the conductive surfaces 13r which F.leku \ Msehk '; cn on a single actuation: - ..: s- and 20c of the foils 13 and 20 and signals of different IVi. '

17 electrical connections are provided. There may therefore be different working groups: =! Iun-

alternatively, the conductive layer of the outer foil will be guided, which is independent of the

z B 2Or. held at ground potential to avoid delayed signals \ on this actuated r.cs-

to ensure static shielding of the unit. position specific circuits are.

The various signals generated by the foils 45 Other possible applications will be possible.

are delivered directly to the summation device 23 when the metal layers on selected elements

during the signal generated by the electrode 11 on the foil in the area of each activation point in separate

Terminal 17 can be divided over a delay device 24 individual areas, and if the Mei.tll-

and then led to the summation device23 surfaces of these foils independently of external foils

vvird. The Verzögerungsintcrvall rf 24 50 are connected gen of Einheil. To produce such

is selected in such a way that known methods can be used between the pulses of the individual faces

resulting pulse train will be the desired spacing. Regardless of the way in which the signals

b _csle ht. generated or grained to a composite signal

In this multi-layer configuration are in the binicrl, they are usually a Vcr

Effect of two or more capacitive switching elements in 55 working device. 7. B. an amplifier, trains

Row sounded. So the electret film 20 acts with the leads.

conductive layer order film 13 as a switching element Although the invention is related to an on / ah

and the electret 13 has been described in conjunction with the specific embodiment

Counter electrode 11 as a further switching element. However, it is obvious to the person skilled in the art that a "

Foils are in the direction of the counter electrode II 60 a variety of combinations of the above be

depressed, and features written between the electret sheet 20 are used if necessary

Unel the conductive layer 13c which can be used as an associated area. For example, the ver with openings

genelcktrode acts, an initial initial configuration according to FIG. 1 with a Viclzali

signal developed. This via the summation advance von Elcktrcl-Folicn according to FIG. 3 adds wci

The signal delivered in the direction of 23 represents the first pulse 65 and, in addition, a protective film of the type shown in FIG.

If the foils are further depressed, the type shown may be provided. Similarly kar,

a second signal is generated when the pushbutton arrangement of FIG. 2 one eir

Foil 13 shifted relative to the counter electrode 11 zigc electret foil in place of the shown Ausgesta

used with a folic and a protective film will. Multiple electrets can also be used in this construction. Enough! On it to point out that the configurations shown are only examples of a variety of alternatives.

As can be seen from the detailed description of the various execution examples of the crlindungsgcmälten Push-button selector device is shown, the structure is extremely simple and critical dimensions do not occur. As a result of modern thin-film technology the entire unit can be made extremely thin so that it can be used in a variety of applications will be used: ·? can. Obviously, individual voting units, i. H. an embodiment. b <M which a disablement point with a Counter electrode is used, can be used when there are single count applications. The means that it is not necessary in the invention Way the entire arrangement of actuation points albeit such an approach has economically beneficial results leads to. The actuation points can be in any desired configuration, e.g. B. circular, in series or the like., are arranged.

In practice it has been shown that the pressure-sensitive Selector is not adversely affected by frequent actuation. At experimental Trials eased the output voltage of one of the in I-i g. 1 similar unit shown Unit cannot be measured after more than 40 (H) OO automatic pressure actuations. The actuations were carried out by means of a motor-driven plunger that acts directly on the metal layer of the electret-l-olic. Nevertheless, it is desirable in the I i g. 2 way shown an additional plastic film for Schulz against damage when operated manually to be provided. In addition, it has been shown. that the Wählcrelementc relative to airborne noise are insensitive. A pistol fired at a distance of about three feet produced a signal to indicate that it was more than 70, ie weaker than that when you press the Drua generated signal was. To operate the selection device, a mechanical pressure force must be applied and no acoustic force is used, d. H. the dial must be printed to operate and cannot be triggered by shouting or the like. If the shah arrangement from cinei Height of about 3 feet was dropped, wai that The signal generated is 30 to 50 db weaker than the signal generated by pressure A design suitable for finger actuation was the Kreuzkopp'iinj produced in nuchbar units 40 db weaker than that caused by pressure actuation signal generated by the unit.

1 sheet of drawings

Claims (9)

Patent claims: 1. Pressure actuation sensitive signaling device with a component and a conductive counter-electrode, which is one with a metallization layer section have provided electret and face each other at a distance, the electrical properties of the conductive counter electrode and the component relative to one another when a pressure is exerted in such a way that the counter-electrode and the component come to one another approximate, be changed, characterized that the component is made by using a charged Elekirct film (121 is formed with at least one metallization layer section (13c ·) as a conductive membrane. where the thickness of the electret film. and their spacing of the conductive counter electrode (11) is matched so that the device against other than Pressure actuation-> forces is insensitive, and that devices (18, 19) for moving the Elcktret-Folic (13) relative to the conductive counter-electrode (11) are provided by applying external pressure actuation forces. 2. Apparatus according to claim 1, characterized by means (15) for local limitation i'er possibility of applying an external pressure actuating force that shifts the electret film. 3. Apparatus according to claim 2, characterized in that the limiting devices one provided with an opening (15), the Elek'.rel film (13) covering cover plate (14), the opening of which is essentially with the counter electrode (11) aligns. 4. Apparatus according to claim 2, characterized in that the limiting devices have a push button (19) substantially aligned with the counter electrode (11). 5. Device according to one of the. , .isspray 1 to 4, characterized in that the electret film (13) has an uncharged and flexible protective film (17) covering it. 6. Device according to one of claims 1 to 5, in which a plurality of components and associated (iegcnel electrodes \ are provided, characterized in that the electret (13: 20) at discrete, im essential points / u one of the two polarities that are aligned with the associated counter-electrode (11) is polarized. 7. Apparatus according to claim 6, characterized in that that two electret tubes lying one above the other (20, 13) with metallized, from the Counter electrodes (II) leading surface sections (20c, 13c) and connecting facilities for forwarding the electrical changes made by shifting the fin / cl of each tier Elekiiei foils Properties for an external formwork (23. 24. 25) are provided. 8. Apparatus according to claim 7, characterized in that the connection devices are delay units (24) for distribution of the individual signals. 9. Apparatus according to claim 8, characterized in that that Suminationseinrichtungcn (23) to combine the expensive signals certain Components provided with the other signals for generating a composite signal are.