DE102009030495A1 - Electrode arrangement for capacitive sensor device or for capacitive sensor for detecting position or approach of object, has sensor electrode and shielding electrode, where sensor electrode is arranged on side of carrier material - Google Patents

Abstract

The electrode arrangement has a sensor electrode (E) and a shielding electrode (SE1), where the sensor electrode is arranged on a side of a carrier material (TM) configured in a substantially planar fashion and having two sides (TM1,TM2). The shielding electrode is arranged on the latter side of the carrier material and serves for shielding the alternating electric field emitted by the sensor electrode with respect to ground. Independent claims are also included for the following: (1) a method for producing a display device; and (2) a device for detecting position or the approach of an object on a display device.

Description

Field of the invention

The The invention relates to a system for detecting the position and / or the approach an object. In particular, the invention relates to a device for detecting the position and / or the approach of an object to a Display device using the electrical according to the invention Circuitry. Furthermore, the invention relates to a film, on which components of the system, in particular electrodes arranged are. Furthermore, the invention relates to a method for the production an approach-sensitive display using a touch-sensitive Screen of the display device and using the film according to the invention.

State of the art

at Screens or displays, in particular for computer screens, mobile communication devices or navigation devices There is a desire to have the functionality of the screens through one Detection of approach to the screen or a recognition of gestures near the screen to thereby, for example, image movements such as Scroll and / or turning on-screen electronic Manually control documents without touching the screen.

For this are off Various solutions are known in the prior art. A solution is based on optical processes with cameras and subsequent image processing, what but expensive and compute-intensive as well as frequent to problems with different or poor lighting conditions leads.

a other, less expensive approach offer so-called capacitive procedures, where an approximation of Hand or finger to the screen through multiple electrodes of a capacitive sensor system detected and the resulting capacity changes evaluated at the electrodes by means of a suitable method become.

special disadvantageous of the solution based on a capacitive method approach is that the screen is at ground potential. This will be the Sensitivity of the electrodes used for gesture detection in the screen area are arranged considerably limited, because one of the electrodes emitted electric field strongly on the grounded screen coupled. This coupling is especially in the case of larger screens disadvantageous. Especially in the area of the screen center has the approach of one Fingers or one hand only a very small effect on one change of the electric field emitted by the electrodes and therefore results only very weak changes a derived sensor signal. This is a fundamental disadvantage All capacitive sensors for gesture recognition and proximity detection.

Of Further, there is a desire to be touch-sensitive Screens for functionality an approximation or gesture recognition to extend, so even in touch-sensitive Screens applications contactless to be controlled or operated by hand.

Object of the invention

task The invention is therefore a system for detecting the position and / or approach an object, in particular a hand or a finger, which avoids the disadvantages mentioned at least partially and an improved sensitivity of the capacitive sensor system as well an afterthought Extension of touch-sensitive Display devices are proximity-sensitive functionality allows.

Inventive solution

According to the invention this Task with a system or an electrical circuit arrangement and a device for detecting gestures, the position and / or the approach an object solved on a display device.

Thereafter, a system or circuit is provided for detecting a position, a gesture and / or the approach of an object, comprising at least one capacitive sensor comprising a sensor electrode, a resonant circuit coupled to the sensor electrode, and a generator for biasing the sensor electrode and an electrical voltage of the resonant circuit, wherein a phase shift of an electrical voltage of the resonant circuit relative to a voltage of the generator indicative of the approach and / or the position of the object to the sensor electrode, wherein at least one shield electrode at a predetermined distance to the sensor electrode can be arranged, for shielding an electrode array of the sensor electrode to ground, wherein at least one coupling electrode between the sensor electrode and the shield electrode can be arranged and coupled to the shield electrode, and wherein the Au Sgang the at least one capacitive sensor via an amplifier circuit to the coupling electrode is switchable to the coupling electrode and the shield electrode in We considerably to the electrical potential of the sensor electrode.

This System or this circuit is characterized in particular characterized in that an improved sensitivity of the capacitive sensor system over conventional ensured capacitive sensor system becomes. By providing a coupling electrode can in particularly advantageously also screens with resistive touch-sensitive Displays to be equipped to screens with gesture and proximity detection.

The amplifier circuit can be configured as a driver circuit, wherein the driver circuit is configured to drive the current to the coupling electrode and the coupling electrode with a to the electrode voltage of the sensor electrode To apply in-phase electrical voltage. So that can an almost field-free space between the sensor electrodes and the Shield electrode are generated, which in turn has a positive effect on the Sensitivity of the capacitive sensor system.

The acted upon electrical voltage can be smaller in amount be as the electrode voltage of the sensor electrode.

Advantageous it is when the shield electrode and the coupling electrode capacitive can be coupled. This is a subsequent upgrade of a Screen, which already conductive structures, eg. B. for contact detection has mechanically particularly easy to do.

Of the Output of the at least one capacitive sensor can via a Multiplexer be coupled to the driver circuit.

Especially It is advantageous if the inductive component of the resonant circuit is formed by a gyrator, wherein the gyrator one over a Condenser feedback operational amplifiers comprising at the input of the capacitive sensor as virtual inductance acts, with the virtual inductor together with the input the capacitive sensor connected sensor electrode and their load capacity forms a parallel resonant circuit to ground.

Of the Output of the operational amplifier can can be coupled to the driver circuit and at the output of the operational amplifier an attenuator, preferably an ohmic voltage divider, be arranged.

ready is also provided a device for detecting gestures, the Position and / or approach an object on a display device, with a circuit arrangement according to the invention, wherein the shield electrode embedded in a transparent protective material is, which can be arranged on the display device, and wherein the shield electrode of the shield of the electrode field of the sensor electrode across from the grounded display device is used.

The Shield electrode and the at least one sensor electrode can each embedded in a carrier material his and the porters can on the surface of the transparent protective material facing away from the display device be arranged. The carrier material can be a transparent carrier material be.

The Display device can be a touch-sensitive Screen and the screen electrode and / or the at least one Sensor electrode can through the conductive Layers of touch-sensitive Screen are formed, wherein the conductive layers of the touch-sensitive screen in time-division multiplexing with an evaluation unit for touch detection and coupled to an evaluation unit for proximity detection are.

there For example, the shield electrode may comprise the coupling electrode.

Provided is also a film comprising a sensor electrodes or a Plurality of sensor electrodes and at least one coupling electrode, wherein the sensor electrodes on one side of the at least one coupling electrode and at a predetermined distance from the at least one coupling electrode are arranged and wherein the film has connections for connecting the Sensor electrodes to an evaluation and for connecting the Sensor electrodes and the at least one coupling electrode to a Driver circuit for producing a substantially field-free Space between the sensor electrodes and the at least one coupling electrode.

Provided is also a method of making an approach sensitive Display device with a touch-sensitive Screen, wherein the touch-sensitive Screen conductive Having structures for detecting a touch, comprising a Step for applying a film according to the invention to the touch-sensitive Screen, wherein the at least one coupling electrode to the screen is facing and wherein the at least one coupling electrode with the conductive one Structures of touch-sensitive Screen can be brought into a capacitive coupling.

The film connections and the conductive structures of the touch-sensitive screen are coupled to an evaluation unit for approach detection, wherein the conductive structures are coupled in time-division multiplexing with the evaluation unit for proximity detection and with a detection unit for touch detection.

Further Advantages and advantageous embodiments of the invention are the Description, the drawings and claims removed.

Brief description of the figures

In the drawing embodiments are schematically simplified and will be described in the following description explained in more detail.

It shows:

1 a principle arrangement of a system according to the invention or a circuit arrangement with a plurality of capacitive sensors;

2 a capacitive equivalent circuit diagram for a capacitive sensor 1 ;

3 a capacitive equivalent circuit diagram for a capacitive sensor with a finger approaching the capacitive sensor;

4 a designed as a gyrator inductive component of the resonant circuit of a capacitive sensor;

5a a frame-shaped arrangement of the electrodes of the system according to the invention;

5b a layered structure of the 5a shown frame-shaped arrangement of the electrodes of the system according to the invention;

6 the basic structure of a resistive touch-sensitive screen;

7 an interconnection of a touch-sensitive screen with an evaluation unit for touch detection;

8th an interconnection of a touch-sensitive screen according to the invention with an evaluation unit for touch detection and an evaluation unit for approach detection;

9 the use of conductive structures of a touch-sensitive screen as shielding electrodes for the system according to the invention, wherein the sensor electrodes are arranged in the form of a frame; and

10 the use of conductive structures of a touch-sensitive screen as shielding electrodes for the system according to the invention, wherein the sensor electrode is designed as a conductive foil.

Detailed description the invention

1 shows a schematic arrangement of a system or circuit arrangement according to the invention.

The Arrangement comprises sensor electrodes E1 to En, each with an associated one capacitive sensor S1 to Sn are coupled. Above the screen or display D is a transparent protective material SM arranged. The protective material SM Can be made of either glass or plastic be. Other for this suitable materials can also be used.

At the bottom or the top (or near below a surface) of the Glass or the film is applied a weakly conductive layer, as shielding electrode SE of the shielding of the sensor electrodes S1 to Sn emitted electric field with respect to the grounded screen D serves. This conductive layer acts opposite the grounded screen D in each case as a shield or as a shield electrode SE, if the voltage applied to the sensor electrodes E1 to En electrode voltage nearly is equal to the voltage applied to the shield electrode SE. The Shield electrode SE and sensor electrodes E1 to En are then on nearly same potential, so that the space between the shield electrode SE and the sensor electrodes E1 to En is almost field-free.

The Screen electrode SE can be part of the display device or the screen D while the sensor electrodes E1 to En independent of the shield electrode SE on the screen D can be attached or attached later can be.

In order to ensure that the sensor electrodes E1 to En are mounted at essentially the same potential even in the case of an attachment of the sensor electrodes independent of the shield electrode SE, or that a substantially field-free space is formed between them, one of the sensor outputs of the capacitive sensors S1 to is respectively formed Sn connected via a multiplexer MUX and a driver circuit T to a coupling electrode SE _K.

The coupling electrode SE _K is arranged in such a way that it lies between the sensor electrodes E1 to En and the shield electrode SE and can preferably be brought into capacitive coupling with the shield electrode SE. In another embodiment, not shown here, the shield electrode SE can be galvanically connected to the coupling electrode SE _K be coupled.

The driver circuit T is configured to drive the current of the coupling electrode SE _K and to apply a voltage to the coupling electrode SE _K , which is in phase with the electrode voltage applied to the sensor electrodes E1 to En. The signal thus generated at the coupling electrode SE _K is capacitively coupled via the glass or the film to the electrically conductive layer or to the screen electrode SE. This ensures that, in any case, a substantially field-free space is formed between the sensor electrodes E1 to En and the shield electrode SE.

The capacitive coupling of the upper side of the glass or the film is particularly advantageous from the point of view of low-cost production, since the entire configuration of sensor electrodes E1 to En and coupling electrode SE _K can be simply placed on the screen D from above for coupling to the screen electrode SE , This also plays an important role in terms of retrofitting screens with proximity functionality.

The mode of action of in 1 shown electric circuit is with reference to 2 explained in more detail.

2 shows a capacitive equivalent circuit of the in 1 shown circuit for a capacitive sensor S.

Between a sensor electrode E and the coupling electrode SE _K acts a capacitance C ₁ . Another capacitance C ₂ is formed in the glass or in the film SM between the coupling electrode SE _K and the conductive layer or shielding electrode SE serving for shielding. The shield electrode SE in turn has a capacitance C ₃ with respect to the grounded screen D.

For the shielding effect of the shielding electrode SE, the voltage u _S applied to the shielding electrode SE is decisive. With an output voltage u _T on the driver T, the voltage u _S then results u _S = U _T / (1 + C ₃ / C ₂ )

Since the output voltage u _{T of} the driver T approximately corresponds to the electrode voltage u _E at the sensor electrode E, the better the shielding effect, the smaller the ratio C ₃ / C ₂ . This can be achieved by constructive measures, for example by selecting suitable distances between the sensor electrodes E and the shield electrode SE. It has been found that even at a ratio of 1 for C ₃ / C _{2 achieved} a high shielding effect.

Out 2 is also apparent that via the coupling capacitance C ₁ between the sensor electrode E and coupling electrode SE _K, a feedback occurs in the sensor circuit, as via the driver circuit T to the sensor S, a loop is formed. This effect can be advantageously exploited for an increase in sensor sensitivity.

The use of a conductive layer or a shield electrode SE in the glass or on a film SM also offers the possibility of using the system according to the invention 1 in addition to proximity detection, it is also possible to realize a touch detection which either enables a switching function independently of the location of the touch or can be used for a coordinate calculation of the finger position, depending on the location of the touch on the screen. Particularly advantageous can be with in 1 shown system realize a Gestendetektion. The touch detection will be described with reference to FIG 3 explained in more detail.

3 shows a capacitive equivalent circuit diagram for a capacitive sensor with an approaching the capacitive sensor finger or with a finger touching the display.

The contact of the glass or the film SM always causes a sudden or very rapid reduction in the voltage u _S on the screen electrode SE, since the screen electrode SE is additionally capacitively loaded via a coupling capacitance C _S emanating from the finger and via the body capacitance C _K. This reduction of the voltage u _S is equivalent to an increase in the load capacitance acting on a sensor electrode E. Accordingly, the signal voltage of the sensor S changes abruptly or very quickly. At the same time a touch of the screen also causes a capacitive coupling to the sensor electrode E, in 3 is shown with a further coupling capacitance C _E. If one approaches each other while touching the display of the sensor electrode E, this results in an additional change in the signal voltage of the sensor S, whereby the distance of the finger to the sensor electrode E can be determined.

In conjunction with the other sensor electrodes, the coordinate of the finger on the screen can thus be determined. However, this is possible with sufficient accuracy only if the coupling C _{S of} the finger relative to the screen electrode SE in comparison to the coupling C _{E of} the finger on the sensor electrode E is not too strong.

This can be achieved by an appropriate design of the electrode configuration, in the screen electrode SE is arranged closer or farther away from the surface of the glass or film SM facing away from the screen. If the screen electrode SE is arranged further away from the surface to be contacted of the glass or the film SM, according to the invention the possibility of distinguishable contact on the screen is obtained. The exact electrode configuration depends on the size of the screen.

In the 1 illustrated capacitive sensors S1 to Sn can operate according to a phase method in which the approximation of the phase shift of a resonant circuit of a capacitive sensor relative to a reference signal of a generator of the capacitive sensor is indicative. When approaching a finger to a sensor electrode E of a capacitive sensor S, the resonant circuit of the capacitive sensor is detuned due to the capacitance change from the originally set resonance. This results in an amplitude and phase change of the signal of the resonant circuit with respect to the generator signal, with which the resonant circuit is applied.

amplitude and phase change can to Detection of an approach to the capacitive sensor S or at the sensor electrode E used become. Most advantageously, however, the phase position is exploited, because you are largely independent of possible amplitude changes the generator signal remains and also an even greater sensitivity regarding capacity changes of the Sensor electrode E reached. Furthermore, when using the phase method the voltage at the resonant circuit are kept low, which is advantageous on the field emission at the sensor electrode E and thus also the EMC problem regarding the Radiation emission reduced. Furthermore, it is a phase method also insensitive to external disturbances on the Reception side.

The inductive component required for a resonant circuit of a capacitive sensor S can be realized by means of a gyrator. The basic structure of a gyrator for a capacitive sensor in a system according to the invention is described with reference to FIG 4 shown.

An operational amplifier OP fed back via a capacitor C _F acts at the input as a virtual inductance L = R ² .C _F , which together with the sensor electrode E and its load capacitance C _L grounded forms a parallel resonant circuit and thereby as a sensitive element with respect to the described phase shift acts. At the same time, the output of the operational amplifier OP is used for switching over the multiplexer MUX of 1 connected coupling electrode SE _K and the screen electrode SE, which is so capacitively coupled to the coupling electrode SE _K , to drive.

Because of the capacitance C ₁ between the sensor electrode E and the coupling electrode SE _K of 2 a feedback loop is formed and thereby the arrangement would tend to oscillate, the output voltage of the operational amplifier OP is divided down by means of an attenuator, which is preferably designed as an ohmic voltage divider, so that the ratio between the output voltage of the operational amplifier OP and the voltage u _T at the coupling electrode SE _{K is} less than one in terms of amount. This ensures stable operation. In addition, the output of the operational amplifier OP can be coupled to the driver circuit T in order to optionally increase the voltage with which the coupling electrode SE _{K is} applied again and to free the coupling electrode SE _K from a capacitive load.

When using the in 4 shown gyrator as an inductive component of the resonant circuit of a capacitive sensor S can in one embodiment of the system according to the invention 1 respectively. 2 This can be realized without driver circuit T, since the ohmic voltage divider itself acts as an amplifier with a gain factor less than 1 and drives the coupling electrode SE _K.

These Arrangement also has the advantage of this feedback the resonant circuit to de-steam and thus a high quality of the circle to reach, which in turn ensures a high proximity sensitivity. This simple and inexpensive electronic realization of a parallel resonant circuit also allows an integration of the entire system in an ASIC.

According to the in 1 According to the invention, any desired electrode configurations consisting of sensor electrodes, coupling electrodes and shielding electrodes can be realized in order to detect an approach or a movement (eg a gesture) in the region of the sensor electrodes.

An example of an arrangement consisting of four line-shaped electrodes EX ₁ , EX ₂ , EY ₁ , EY ₂ in a multi-layer structure is shown in FIG 5a shown. 5a shows a frame-shaped arrangement R, which for retrofitting for an approach functionality (or gesture function) can be placed on top of a display D. The strip-shaped electrodes EX ₁ , EX ₂ , EY ₁ , EY ₂ are arranged here along the four outer edges of the frame R.

The layer structure of in 5a gezeig th frame-shaped arrangement, which z. B. can be realized with several superimposed films, is in 5b shown schematically.

The sensor electrode E and a plurality of coupling electrodes SE _K are embedded in a carrier material B. The carrier material may be, for example, a film which may be transparent. The coupling electrodes SE _K are galvanically connected to each other and are driven by the same driver circuit T.

The at the top of the substrate edge arranged coupling electrode allows this a shielding effect to the outside to the edge area of the display D. The at the bottom of the substrate arranged coupling electrode is used together with the in the glass or the film SM let screen electrode SE to the sensor electrode Protect SE against the display.

The striped arrangement has the advantage that the coordinates of the position of a finger can be calculated with a simple algorithm for an X / Y coordinate system on the display surface, since z. For example, the signals generated at the X-electrodes EX ₁ and EX ₂ are independent of the signals at the Y-electrodes EY ₁ and EY ₂ .

A coordinate calculation with four strip-shaped sensor electrodes can be carried out, for example, on the basis of an evaluation of the phase position Φ _X or Φ _{Y of} the X electrodes or the Y electrodes. For this purpose, the phase difference and the phase sum of the X or Y electrode pairs is advantageously determined, ie AΦ _X = Φ _X1 - Φ _X2 and ΣΦ _X = Φ _X1 + Φ _X2 respectively. ΔΦ _Y = Φ _Y1 - Φ _Y2 and ΣΦ _Y = Φ _Y1 + Φ _Y2 .

Thus, a linearization of the coordinate determination is possible, since in the difference formation generally results in a non-linear course of the phase difference. For the linearization can first (for each pair of electrodes) a function Ψ _X = _X ΣΦ - Φ _X0 Ψ _Y = ΣΦ _Y - Φ _Y0 To be defined. Hence ΔΦ _X / Ψ _X = (Φ _X1 - Φ _X2 ) / (Φ _X1 + Φ _X2 - Φ _X0 ) ΔΦ _Y / Ψ _Y = (Φ _Y1 - Φ _Y2 ) / (Φ _Y1 + Φ _Y2 - Φ _Y0 ) with a suitably chosen constant Ψ _X0 or Φ _Y0 to obtain the linearization for each in the X direction and Y direction. Due to the resulting approximate proportionality, the position of a finger can be determined very easily.

With the in 5a and 5b shown frame-shaped structure, which consists of the layer SM with the shield electrode SE and the layer B with the sensor electrodes S and the coupling electrodes SE _K , can be extended in a very simple way an existing display to the functionality of a proximity determination or gesture determination.

As well let yourself according to the invention the system integrate into an existing display by already in the display existing electrically conductive Structures also for the system according to the invention be used.

In order to can for example, resistive touch-sensitive Displays can simply be extended by the mentioned functionality by the already existing conductive Structures of the touch-sensitive Displays are used.

6 shows the construction of a resistive touch-sensitive display (touch screen). The resistive touch-sensitive display essentially consists of two opposing conductive layers 20 . 30 (Foil - foil or ITO glass - foil), which by small distance dots 10 are separated from each other. The touch-sensitive display is arranged above the display device. The touch-sensitive display has measurement leads that conduct a voltage across the point of contact when touched by a finger or stylus.

7 shows the coupling of in 6 shown resistive touch-sensitive displays via display connection cable 70 and a plug 60 with an evaluation unit μC for detecting touches.

According to the invention, these two conductive layers 20 . 30 (regardless of the specific touch screen design) can be used as electrode structures for the inventive system. In order to maintain the existing function of the touch detection of the touch screen, existing function of the touch detection is coupled in the time-division multiplex method with an evaluation unit GestIC according to the invention for proximity detection. Such a coupling is in 8th shown.

According to the invention, there are several possibilities of realization, wherein always at least one conductive layer of the touch-sensitive Displays is used either as a sensor electrode E or as a shield electrode SE.

A first possibility is the lower layer facing the D screen 20 to use as the shield electrode SE and the upper layer 30 as a sensor electrode E. This can be retrofitted without additional electrodes, a resistive touch-sensitive display. At the same time, the shield electrode SE also forms the coupling electrode SE _K.

Another, in 9 The possibility shown is to use both conductive layers of the resistive touch-sensitive display together as a common shield electrode SE. Alternatively, only one of the two conductive layers can be used as the shield electrode SE. The sensor electrodes EX ₁ , EX ₂ , EY ₁ , EY ₂ necessary for the system according to the invention can be arranged as a separate part on the screen. Here, too, an embodiment can be used as a frame structure, wherein only the sensor electrodes are arranged on the frame structure. On the frame structure, a single circumferential sensor electrode can be arranged, whereby a simple approach to the display without position determination is detected. The frame structure can be galvanically coupled to the evaluation unit, for example by means of press or clip contacting.

Another possibility is to use at least one conductive layer of the resistive touch-sensitive display as the screen electrode SE and the sensor electrode E in the form of an additional conductive film 100 (eg ITO film) and apply it to the existing touchscreen, as in 10 shown. In the in 10 In the embodiment shown, a single sensor electrode E is applied to the touch screen as a continuous conductive film. This makes it easy to implement simple approach to the display without position determination.

alternative can also be a foil with several independent sensor electrodes E or a film with segmented sensor electrodes E on the touch screen be applied, for example, with 4 or 16 square or rectangular sensor electrodes. Several are possible in parallel running strip-shaped designed sensor electrodes, so advantageously about the X position of the approaching Finger is detectable. With increasing number of sensor electrodes let yourself the resolution the detection, about a gesture further increase.

This has the advantage that at least one electrode surface of the saved according to the invention system can use the full functionality of gesture recognition by using the conductive one Structures of the touchscreen yet with a better sensitivity as provided in prior art systems can. This also results in a much simpler mechanical Integration, which means a significant cost reduction in the manufacturing process as well as in the material costs.

The inventive system is characterized by a high degree of flexibility, especially in the adaptation to different display sizes, without that the sensitivity decreases with larger displays. It can diverse Application-specific electrode configurations for detecting even complicated gestures will be realized. The detection of the approach takes place by means of a Phase method, with the necessary function of a parallel resonant circuit with a single operational amplifier to create a virtual inductance is produced. This purely electronic solution therefore also allows a place saving and cost effective Integration in an ASIC for a multiple electrode system.

Claims (16)

Circuit arrangement for detecting the position and / or the approach of an object, comprising at least one capacitive sensor (S), comprising a sensor electrode (E), a resonant circuit coupled to the sensor electrode (E) and a generator for acting on the sensor electrode (E ) and the resonant circuit formed system with an electrical voltage, wherein a phase shift of an electrical voltage of the resonant circuit relative to an electrical voltage of the generator indicative of the approach and / or the position of the object to the sensor electrode (E), wherein - at least one shield electrode ( SE) can be arranged at a predetermined distance from the sensor electrode (E), for shielding an electrode field of the sensor electrode (E) from ground; - At least one coupling electrode (SE _K ) between the sensor electrode (E) and the shield electrode (SE) can be arranged and with the shield electrode (SE) can be coupled; and - the output of the at least one capacitive sensor (S) via an amplifier circuit to the coupling electrode (SE _K ) is switchable to the coupling electrode (SE _K ) and the shield electrode (SE) substantially to the electrical potential of the sensor electrode (E) bring. Circuit arrangement according to claim 1, wherein the amplifier circuit is a driver circuit (T) and wherein the driver circuit (T) is designed, to drive the current at the coupling electrode (SE _K) and the coupling electrode (SE _K) with a voltage to the electrode of the sensor electrode (E) to apply phase voltage. Circuit arrangement according to claim 2, wherein the acted upon electrical voltage is smaller in magnitude is the electrode voltage of the sensor electrode (E). Circuit arrangement according to one of the preceding claims, wherein the shield electrode (SE) and the coupling electrode (SE _K ) are capacitively coupled. Circuit arrangement according to one of claims 2 to 4, wherein the output of the at least one capacitive sensor (S) via a Multiplexer (MUX) with the driver circuit (T) can be coupled. Circuit arrangement according to one of claims 2 to 5, wherein the inductive component of the resonant circuit by a Gyrator is formed. Circuit arrangement according to claim 6, wherein the gyrator includes a via a capacitor (C _F) fed-back operational amplifier (OP), which at the input of the capacitive sensor (S) acts as a virtual inductor, wherein the virtual inductance together with the (at the input of the capacitive sensor S) connected to the sensor electrode (E) and the load capacitance (C _L ) forms a parallel resonant circuit to ground. Circuit arrangement according to claim 7, wherein the output of the operational amplifier (OP) with the driver circuit (T) is coupled and wherein at the output of the operational amplifier (OP) an attenuator, preferably an ohmic voltage divider is arranged. Device for detecting the position and / or the approach an object on a display device (D), comprising a Circuit arrangement according to one of the preceding claims, wherein the shield electrode (SE) in a transparent protective material (SM) is embedded, which can be arranged on the display device, and wherein the shield electrode (SE) of the shield of the electrode array the sensor electrode (E) opposite the grounded display device is used. The device of claim 9, wherein the shield electrode (SE) and the at least one sensor electrode (E) each in a carrier material are embedded and wherein the carrier (B) on the display device (D) facing away from the surface the transparent protective material (SM) is arranged. Apparatus according to claim 10, wherein the carrier material a transparent carrier material is. Device according to one of claims 9 to 11, wherein the display device (D) a touch-sensitive Screen is and wherein the shield electrode (SE) and / or the at least a sensor electrode (E) through the conductive layers of the touch-sensitive Screen are formed, wherein the conductive layers of the touch-sensitive screen in time-division multiplexing with an evaluation unit for touch detection (μC) and coupled to an evaluation unit for evaluation detection (GestIC) are. Apparatus according to claim 12, wherein the shield electrode (SE) comprises the coupling electrode (SE _K ). Foil comprising a plurality of sensor electrodes (E) and at least one coupling electrode (SE _K ), wherein the sensor electrodes (E) arranged on one side of the at least one coupling electrode (SE _K ) and at a predetermined distance from the at least one coupling electrode (SE _K ) and wherein the film has connections for connecting the sensor electrodes (E) to an evaluation unit (GestIC) and for connecting the sensor electrodes (E) and the at least one coupling electrode (SE _K ) to a driver circuit (T) for producing a substantially field-free space between the sensor electrodes (E) and the at least one coupling electrode (SE _K ). A method for producing an approach-sensitive display device with a touch-sensitive screen, wherein the touch-sensitive screen has conductive structures for detecting a touch, comprising a step for applying a film according to claim 14 on the touch-sensitive screen, wherein the at least one coupling electrode (SE _K ) facing the screen and wherein the at least one coupling electrode (SE _K ) can be brought into a capacitive coupling with the conductive structures of the touch-sensitive screen. The method of claim 15, further comprising: one Step for coupling the film leads and the conductive structures the touch-sensitive screen with an evaluation unit for approach detection (GestIC), being the conductive one Time division multiplex structures with the evaluation unit for proximity detection (GestIC) and coupled to an evaluation unit for contact detection (μC) become.

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