RU2575475C2 - Technologies of measurement of force and real capacitance contact for capacitance contact detectors - Google Patents

Abstract

FIELD: measurement equipment.

SUBSTANCE: invention relates to information input devices and may be used to measure capacitance in capacitance contact detectors. Methods, systems and device are proposed, connected to contact detectors, which are made as capable of measurement of capacitance contact and force applied to the detector by a user. Some versions include measurement of force and capacitance contact simultaneously in a sensor capacitance detector.

EFFECT: increased accuracy of produced data.

40 cl, 8 dwg

Description

FIELD OF THE INVENTION

This disclosure relates to techniques for measuring capacitance in capacitive touch sensors, for example, when measuring force and indeed capacitive touch simultaneously in a sensor.

State of the art

Touch sensors, for example, sensors used in touch screens for portable devices and for monitors, are configured to detect changes in capacitance in order to generate electrical signals based on certain changes and send the generated electrical signals to a receiving device for subsequent processing.

SUMMARY OF THE INVENTION

This description explains technologies generally associated with touch sensors that are capable of measuring truly capacitive touch and / or the force applied to the sensor by a user.

In general, some aspects of the invention described herein may be practiced in methods that utilize a sensor. Other embodiments of this aspect include corresponding systems, apparatus, and computer programs configured to implement methods encoded on computer storage devices.

In general, another aspect of the invention described herein may be practiced in methods that include actions associated with a capacitive touch sensor. The sensor includes a first matrix (for example, repeating linear patterns or an ordered arrangement of lines) of conductors arranged in rows, with the conductors in the first matrix being arranged substantially parallel to each other. The sensor includes a second matrix of conductors arranged in columns, wherein the columns of conductors in the second matrix are arranged substantially parallel to each other. Columns of conductors in the second matrix are located under the first matrix of conductors, and conductors in the second matrix are arranged in a direction that is substantially perpendicular to the direction of the rows of conductors in the first matrix. The sensor includes a sheet having dielectric material, the sheet being under a second array of conductors.

The sensor includes a grounding pad located under the sheet. The first and second matrices are configured to form an electric field with electric field strength lines that go in the first direction to the sensor user and in the second direction to the ground plane.

Each of these and other embodiments may optionally include one or more of the following features. The width of the conductors, measured in one row in the first matrix, can be less than the separation distance measured between the adjacent edges of two adjacent rows of the first matrix, and the width of the conductors, measured in one column in the second matrix, can be less than the separation distance measured between the adjacent edges of two adjacent columns in the second matrix. The grounding pad can be placed with the ability to at least partially break off some lines of the electric field, going in the second direction. The sensor may be configured to detect interruption in electric field strength lines in a first direction. The sensor can be configured to detect interruption of the electric field strength lines arising as a result of presenting an object that is located near the sensor in the electric field lines of the first direction. The object may be a finger or some other part of the sensor user's body. The sensor may include transmitting devices and receiving devices. The sensor can be configured to perform the following operations: transmitting, using transmitting devices, signals at at least two different frequencies in the first or second matrix of conductors; receiving, using receivers, signals at least two different frequencies in the other of the first or second matrix of conductors; estimating the capacitance value at each of two different frequencies using the received signals; determining that the object is a finger or some other part of the user's body if the estimated capacitance values at two frequencies differ by two or more times; and determining that the object is not an object that allows the formation of a truly capacitive touch signal (for example, with a finger or some other part of the human body), and the activation of the sensor is determined by the measured force if the estimated capacitance values at two frequencies do not differ two or more times. The sensor may be configured to receive external force from touching or pressing the sensor. The sensor may be configured to compress at least the conductors in the first and second matrices in the direction of the ground plane after receiving an external force, and the sensor may also be configured to reduce the capacitance of the sensor when an external force is applied to the sensor. The sensor may include a characteristic of the capacitance at which the level of the measured capacitance decreases monotonically from the moment when the object is located near the sensor to the moment when the object touches and presses the sensor. The grounding pad may include an indium tin oxide (ITO) sheet or a transparent conductor. The grounding pad may include wires or metal formed on a liquid crystal display (LCD). The sensor may have such a configuration in which one of the grounding pad and the second sheet of material are formed below the sheet having dielectric material, while the second sheet of material has a dielectric constant that is higher than the dielectric constant of the deformable dielectric material. The sensor may be configured in such a way that either a ground plane can be formed below a sheet having a deformable dielectric material, or a second sheet of material can be formed above a sheet having a deformable dielectric material, for which the second sheet of material can have a dielectric constant that exceeds the dielectric constant of the sheet deformable dielectric material. The sensor may include indium tin oxide (ITO) on a polyester sheet (PET). The sensor may have opaque metal tracks on a polyester sheet (PET) or plastic material. The conductors may include a transparent conductive material placed in the template so as to form an edge electric field between the first and second matrix of conductors. Rows and columns may include diamond-shaped patterns at disjoint locations of conductors of the first and second matrices. The conductors in the second matrix can be placed between the first matrix of conductors and the deformable dielectric, and the deformable dielectric can be placed between the conductors in the second matrix and the ground plane.

In general, another aspect of the invention described herein may be practiced in methods that include actions associated with a capacitive touch sensor. The sensor includes a first matrix of conductors arranged in rows, wherein the rows of conductors in the first matrix are arranged substantially parallel to each other, and the width of the conductors, measured on one line in the first matrix, is less than the separation distance between the respective conductors, measured between adjacent edges two adjacent rows of the first matrix. The sensor includes a second matrix of conductors arranged in columns, wherein the columns of conductors in the second matrix are arranged substantially parallel to each other, and wherein the conductors in the second matrix are under the conductors in the first matrix. The conductors in the second matrix are arranged in a direction that is essentially perpendicular to the direction of the first matrix of conductors, and the width of the conductors, measured in one column in the second matrix, exceeds the separation distance between the respective conductors, measured between the adjacent edges of two adjacent columns in the second matrix. The sensor includes a sheet having dielectric material, the sheet being under a second array of conductors. The sensor includes a third array of conductors arranged in rows, the rows of conductors in the third array being arranged substantially parallel to each other, and the conductors in the third array being under the sheet. The rows of conductors in the third matrix are arranged in a direction that is essentially perpendicular to the direction of the columns of conductors in the second matrix, and the width of the conductors, measured in one row of the third matrix, exceeds the separation distance between the corresponding conductors, measured between the adjacent edges of two adjacent rows in the third matrix.

Each of these and other embodiments may optionally include one or more of the following features. The sensor may include a force-sensitive sensor and a truly capacitive touch sensor, wherein the truly capacitive touch sensor may include first and second matrix conductors, and the force-sensitive sensor may include second and third matrix conductors and a sheet having dielectric material . The force-sensitive sensor can be configured to first measure the first capacitance for the capacitance of the parallel capacitor plates between the intersections of the conductors of the second and third arrays, and the truly capacitive touch sensor can be configured to second measure the second capacitance associated with the edge electric field between the first and second matrices of conductors. The sensor may be configured to determine whether or not an object is located close to touching the sensor by an edge electric field. The sensor may be further configured to determine whether or not the object applies force to the sensor. The sensor can be configured to lower the level of the second capacitance as the object approaches the touch of the sensor. The sensor may be configured to raise the level of the first capacitance as the object touches and applies force to the sensor. The sensor may include indium tin oxide (ITO) on a polyester sheet (PET). The sensor may include opaque metal tracks on a polyester sheet (PET) or plastic material. The conductors may include transparent conductive material placed in the template so as to form an edge electric field between the first and second matrixes of conductors. The conductors in the second matrix can be placed between the first matrix of conductors and the deformable dielectric, and the deformable dielectric can be placed between the conductors in the second matrix and the third matrix of conductors.

In general, another aspect of the invention described herein may be practiced in methods that include actions associated with a capacitive touch sensor. The sensor includes a first array of conductors arranged in rows, a second array of conductors arranged in columns that are substantially perpendicular to the rows of conductors in the first array, at least one transmitter connected to the conductors in one of the first and second matrix of conductors, and at least one receiving device connected to conductors in another of the first and second matrix of conductors. A method for taking measurements in a sensor comprises transmitting, using at least one transmitting device, signals at at least two different frequencies that form an electric field between at least one of the conductors in the first matrix and at least one of the conductors in the second matrix, the first and second matrices are configured to form an edge electric field that goes towards the sensor user, and provide a definition of the interruption The field resulting from an object that is located close to the sensor. The method comprises receiving, using at least one receiving device, signals with two or more different frequencies, estimating the capacitance value at each of two or more different frequencies using the received signals, and determining whether or not the estimated value is different capacitance at each of two or more frequencies approximately two or more times. The method involves calculating the relationship between the estimated capacitance values and comparing the relationship with a threshold value, the threshold value comprising a value that is approximately two. The method may also include calculating the difference between the estimated capacitance values and comparing the difference with a threshold value. The method includes determining whether or not the object allows the formation of a truly capacitive touch signal (for example, a finger or some other part of the human body), and whether or not the sensor is activated by measured force, based on the results of comparing the ratio or difference between the estimated capacitance values at two or more frequencies. Each of these and other embodiments may optionally include one or more of the following features. The method may include determining that the object is a finger or some other part of the human body of the user of the touch sensor, if the estimated capacitance values at two frequencies differ approximately two or more times. The conductors in the first matrix can be arranged substantially parallel to each other, and the conductors in the second matrix can be arranged substantially parallel to each other. The conductors in the second matrix may be under the conductors in the first matrix. The width of the conductors, measured in one row in the first matrix, can be less than the separation distance between the corresponding conductors, measured between the adjacent edges of two adjacent rows of the first matrix, and the width of the conductors, measured in one column in the second matrix, can be less than the separation distance between the corresponding conductors measured between adjacent edges of two adjacent columns in a second matrix. The sensor may include a sheet having dielectric material, the sheet may be under a second array of conductors; and the sensor may include an earth ground located beneath the sheet. With respect to frequencies, at least two different frequencies may differ in a ratio of approximately four to one. The sensor may include a truly capacitive touch sensor. The sensor may include a force-sensitive sensor and a truly capacitive touch sensor, wherein the truly capacitive touch sensor may include conductors in the first and second arrays, and the force-sensitive sensor may include conductors in the second array, conductors in the third matrix, and sheet having dielectric material. The conductors in the first matrix can be arranged essentially parallel to each other. The width of the conductors, measured in one row in the first matrix, can be less than the separation distance between the respective conductors, measured between the adjacent edges of two adjacent rows of the first matrix. The conductors in the second matrix can be arranged essentially parallel to each other. The conductors in the second matrix may be under the conductors of the first matrix. The width of the conductors, measured in one column in the second matrix, may exceed the separation distance between the respective conductors, measured between the adjacent edges of two adjacent columns in the second matrix. The sheet may be under the conductors of the second matrix. The conductors of the third matrix can be arranged in rows, and the conductors in the third matrix can be arranged essentially parallel to each other. The conductors in the third matrix may be under the sheet. The conductors in the third matrix can be placed in a direction that is essentially perpendicular to the direction of the conductors in the second matrix, and the width of the conductors, measured in one row in the third matrix, can exceed the separation distance between the corresponding conductors, measured between adjacent edges of two adjacent rows in third matrix. Two different frequencies may include a first frequency and a second frequency, and the first frequency may be higher than the second frequency. The method may also include receiving signals for the second frequency in at least one receiving device that have a higher current than signals received for the first frequency. The sensor may include indium tin oxide (ITO) on a polyester sheet (PET). The sensor may have opaque metal tracks on a polyester sheet (PET) or plastic material. The conductors may have a transparent conductive material placed in the template so as to form an edge electric field between the first and second matrix of conductors. Rows and columns can have diamond-shaped patterns at disjoint locations of conductors of the first and second matrices.

Details of one or more embodiments of the invention described in this detailed description are set forth in the accompanying drawings and in the description below. Other features and aspects of the invention will become apparent from the description, drawings and claims.

Brief Description of the Drawings

Figure 1 illustrates a diagram of a matrix of rows and columns for a touch sensor.

2 illustrates a diagram of another example of a row and column matrix for a touch sensor.

Figure 3 illustrates a graph of the measured capacitance in comparison with the perceived touch force or proximity signal received by the touch sensor of figure 2.

Figure 4 illustrates a matrix diagram of rows and columns for a touch sensor.

FIG. 5 is a diagram illustrating edge fields that exist around the row and column of the touch sensor of FIG. 4.

6 illustrates a graph of a measured capacitance versus a perceived touch force or proximity signal received by a sensor.

7 illustrates a circuit diagram of a hybrid touch sensor.

Fig. 8 illustrates a matrix diagram of rows and columns for a touch sensor, wherein the rows and columns have a rhombic pattern.

Similar reference numerals and designations in various figures indicate similar elements.

DETAILED DESCRIPTION OF THE INVENTION

In the capacitive touch screen, the sensors are made of electrically conductive rows and columns, the rows and columns being movable to receive the force exerted by the sensor user. Rows and columns intersect each other approximately perpendicularly and form a two-dimensional matrix. An electronic controller for such a touch screen should measure the capacitance from each row to each column at each intersection, forming m * n measurements for a matrix with m rows and n columns. The capacitance is measured by applying a time-varying excitation voltage in each conductor (which is arbitrarily allowed here as a column current) and measuring the current forming a connection with each row. Several rows are measured in parallel, and the process is repeated sequentially for each column or partially parallel with the orthogonal forms of excitation signals used in several columns. For example, orthogonal waveforms of the excitation signals can be used in several columns, as described in patent application (US) No. 12/838419, filed July 16, 2010, which is fully incorporated herein by reference.

If the user's finger approaches one of the intersections, then the capacity at this intersection will change. The user's finger is conductive, has a dielectric constant different from the dielectric constant of air, and to the extent that it is conductive, it has some connection through the user's body to the ground node of the controller circuit. Some combination of these effects leads to a change in capacitance, which can decrease (as the current flows from the transmitting device to the user's body and to the ground, and not from the transmitting device to the receiving device) or increase (as the current flows from transmitting device to the user's finger and from the user's finger to the receiving device; the user's finger is more conductive and has a higher dielectric constant than air). The mode in which the user's finger leads to a decrease in capacitance is carried out at higher frequencies, which ensures the transfer of greater total energy in a given integration period, which allows a higher signal-to-noise ratio (SNR). The waning mode is therefore used every time a truly capacitive touch is measured in this disclosure.

The “true capacitive touch" measurement is used because it has zero impact force. It responds to the user's touch position, not to force, and therefore responds to even the lightest touch. However, in some applications, analog measurement of the user's touch force provides a useful additional degree of freedom.

For example, a force can be converted into a capacitance by constructing a capacitor with parallel plates with a deformable dielectric between the plates. When a force is applied to the capacitor, the dielectric material is deformed and allows the plates to come closer to each other. This increases the measured capacity. An array of such sensors can be constructed, for example, with wide, overlapping rows and columns, and dielectric material between the rows and columns. This matrix can be scanned in a similar way in order to measure a truly capacitive touch. The design of force-sensitive sensors also makes it possible to activate the device using objects other than a finger, for example, using a stylus tool, for example, a solid plastic rod. Everything that can be used to apply force (including, for example, a non-conductive plastic object) can be used to provide a signal corresponding to the strength of the sensor. An example of such a sensor is reproduced as FIG. 1.

In the row and column matrix for the touch sensor 100 shown in FIG. 1, the touch sensor 100 includes transparent conductive rows and columns. The touch sensor 100 has line conductors 130 formed over the deformable dielectric 110. The deformable dielectric 110 is formed over the column conductors 120. These conductors can be made of indium tin oxide (ITO), but other materials, such as silver nanowires, can also be used. or larger metal wires that are slightly or strongly opaque, but small enough so that they are relatively invisible. The illustrated configuration results in conductors placed in a two-dimensional orthogonal matrix, for example, when the line conductors are substantially parallel to the X axis and the column conductors are substantially parallel to the Y axis.

The touch sensor 100 includes wide columns and wide rows that overlap, resulting in the capacitance of the parallel capacitor plates in the overlap areas between the rows and columns. In figure 1, the dielectric 110 is deformable, and rows and columns are placed, for example, on flexible fragments of indium and tin oxide (ITO) on a polyester sheet. When the touch sensor 100 receives a force exerted by an external force, for example, by a user's finger, the dielectric 110 deforms and reduces spacing between rows and columns in the pressed region, resulting in an increase in the measured capacitance of this region. The capacity of the row and column matrix can be read to measure the capacity at each m * n intersections independently. 1, the electric field is in the row and columns, so that the sensor mainly responds to the force applied to the sensor. The force may include physical pressure on the sensor resulting from touching by the user's finger or by some other conductive or non-conductive object, such as a stylus tool or some other non-conductive object.

In another architecture, instead of measuring the capacitance from each row to each column, it is possible to measure the capacitance from each row or column to the ground. In a system using this construction with m rows and n columns, m + n dimensions are performed, not m * n. In this case, the capacitance of the parallel capacitor plates will occur between the row or column and the ground, and not between the row and column. By adapting this architecture, a force that is applied at multiple points can produce a result that is not unique to locations where the force is applied. For example, the forces in positions (1, 2) and (3, 4) form an increased capacity in rows 1 and 3 and columns 2 and 4; but the forces at positions (1, 4) and (3, 2) also form an increased capacity in identical rows and columns. Heuristic methods can then be used to then try to choose between competing potential source locations for an initiating force, for example, by considering the sequence in which the points are touched. However, the m * n architectures explained below should not use heuristic methods in order to choose between competing potential source locations for an initiating force. The features described below can offer m * n architectures that provide correct results when two points touch almost simultaneously, or when points move in such a way that they are located along a horizontal (parallel to rows) or vertical (parallel to columns) line.

2 shows a touch sensor 200 having an array of rows and columns. The touch sensor 200 has transparent conductive rows and columns. The touch sensor 200 has line conductors 230 located on top of the deformable dielectric 110. The deformable dielectric 110 is placed above the column conductors 120. For the reasons described below, the touch sensor 200 in FIG. 2 has relatively narrow line conductors 230 with relatively wide gaps between each of the lower case wires. conductors.

The design of FIG. 2 forms both the aforementioned capacitance of the parallel capacitor plates and the edge capacitance, which can be interrupted by the user's finger. This design measures both the actual capacitive touch from the edge field and the force from the capacitance of the parallel capacitor plates as the material deforms between the row and column. This design orientates the upper conductors in a relatively scattered mutual orientation with a gap between them, to allow the field to form an interference band at the edges; an example of this design is displayed as FIG. 2, but other designs with this property are also contemplated. For example, the rhombic pattern 800, as shown in FIG. 8, can be configured to have this property using the edge field between the rhombuses and the capacitance of the parallel capacitor plates when rows 820 and columns 830 intersect each other or form an interdigital pattern.

2, the line conductors 230 are narrow rather than wide, so that there is a large spacing between the line conductors 230 in order to reduce the capacitance of the parallel capacitor plates between the line conductors 230 and the column conductors 120 and allow the formation of an edge field from the line conductors 230, so that an edge field violation can be detected by a sensor to provide an edge capacitance for the touch signal (without force). Similarly to FIG. 2, other implementations may be configured, for example, the rhombic pattern 800 in FIG. 8 or interdigital patterns.

As described above, the touch sensor 200 of FIG. 2 can serve as either a “truly capacitive touch sensor" or a "force-sensitive sensor", respectively, by measuring changes in the edge field and electric field in the dielectric. For example, as a force-sensitive sensor, the touch sensor 200 operates similarly to the touch sensor 100 of FIG. 1 when the capacitance of the parallel capacitor plates is measured, resulting from the force applied to the touch sensor, providing an additional degree of freedom. For example, with a user's finger, the amount of force applied by the user to touch may provide an additional degree of freedom, such as a light touch to indicate one type of instruction, and a stronger touch to indicate a different type of instruction. The designs of force-sensitive sensors can also enable the touch sensor 200 to be activated using objects other than a finger, for example, using a stylus tool (e.g., a solid plastic rod or any conductive or non-conductive object) to provide a signal corresponding to the force for the sensor. For an applied force with a relatively small contact area, for example, the force can be measured completely at one intersection in the matrix, and this measurement can be proportional to the applied force. For an applied force with a relatively large contact region, for example, the force can be measured at several intersections in the matrix, and these measurements can be proportional to the integral of this force in the region of each particular intersection, and therefore the applied pressure. In this disclosure, terms for force and pressure can be used interchangeably. In some implementations, the signal generated by the force in the touch sensor may be an analog measurement of the user's touch force.

In contrast, and as indicated above, in the “truly capacitive touch sensor” mode, the touch sensor 200 generates measurements despite the lack of force. In this sense, true capacitive touch is measured by disturbance in the electric field when the user's finger appears nearby or interferes with the edge field of the sensor. Thus, a truly capacitive touch signal is generated in the touch sensor 200, even if the user does not apply pressure to the sensor, since a measurable change in capacitance can be determined when the user's finger appears near the edge of the sensor. Since the user does not have to apply force to activate the sensor, the resulting frictional force is absent if the user's finger moves in the plane of the sensor and the user does not feel this undesirable frictional resistance on the user's finger. Conversely, a truly capacitive touch sensor can respond to a user's finger position rather than force, and therefore can even respond to the lightest touch from a user.

In FIG. 3, the measured capacitance 310 is related to the perceived touch force based on the corresponding proximity signal 320 received by the touch sensor 200 in FIG. 2. In particular, as demonstrated by FIG. 3, as the user's finger approaches the touch sensor 350, resulting in a gradual decrease in the measured capacitance 310 when the user's finger breaks the edge field from row to column. The capacity due to the edge field is the predominant capacity in this case. After the point at which the user's finger touches the sensor 360 and begins to apply an increasing force 370, the capacitance increases as the capacitance of the parallel capacitor plates becomes more and more the predominant capacitance. This represents a non-monotonic transfer function from measurements of perceived touch force for a capacitance. As a consequence of the non-monotonic transfer function illustrated by FIG. 3, a user who touches and presses strongly enough on the touch sensor can increase the measured capacitance of the parallel capacitor plates to the point where this capacitance of the parallel capacitor plates biases the decrease in the measured capacitance corresponding to the interaction of this user for edge capacity effects and providing results that completely confuse whether the user touches or tries to touch to the sensor.

There may be other measurements performed in other implementations of touch sensors. For example, in some other implementations, capacitance can be measured from each row and column to ground, and not from each row to each column, thereby making m + n measurements instead of m * n measurements. In this case, the capacitance of the parallel capacitor plates will occur between the row or column and the ground, and not between the row and column. Some of these touch sensor implementations using m + n measurements may not be able to independently determine each force (or their location) when the force is applied at several points, even through the use of complex modeling and calculations.

As mentioned above, when a user touches a capacitive touch sensor, at least two different effects are observed. Firstly, part of the energy flowing from the transmitting device can flow into the user and return to earth through the parasitic capacitance of the user for this node. This parasitic capacitance can occur, for example, if the user holds the metal case of the device, even from a non-conductive coating, or in the event of a malfunction through the user's finger, since the sensor pitch can be accurate enough so that his finger can also be close to other elements in the matrix, in which some elements are grounded. This first effect can reduce the total energy that flows into the receiver. Secondly, part of the energy flowing from the transmitting device can form a connection with the user's finger through the user's tissue and then from the user's finger with the receiving device. Since the dielectric constant of the user's finger, which is approximately identical to the dielectric constant of salt water, exceeds the dielectric constant of air, this allows to increase the coupling effect and to increase the received energy.

These two effects can form different reactions for the flow of energy. For example, depending on which effect prevails, there may be a non-monotonic relationship between the measured signal and the distance from the user's finger to the sensor. Based on this, in order to increase the performance of the sensor, touch sensors can be configured to operate in strictly increasing or strictly decreasing mode, so that they have a monotonous relationship. A strictly decreasing mode can demonstrate particularly good performance in some implementations, since this mode can be performed at higher frequencies. Effects corresponding to a strictly decreasing mode can also occur with a large separation between the user's finger and the touch sensor (because when the user's finger becomes very close to the sensor, the effect in which the current forms a connection from the transmitter to the user's finger and then through the user with receiving device, prevails and leads to increased capacity). This may provide greater glass thickness for the sensor cover. However, some other implementations may use strictly incremental mode. As described below, there may be other effects in relation to the mode, which are a function of frequency.

As illustrated by the example shown in FIG. 4, in some implementations, it is possible to position the sensor such that a force acts on the first edge capacitance and a user's finger can influence the second and different edge capacitance. This arrangement can be achieved using an electrode template that forms a significant edge field both on the front (to the user) and on the back (to the display) side of the sensor. A narrow-wire pattern may have this property, for example, as a rhombic 800 pattern (Fig. 8), either an interdigital pattern or other patterns. The sensor may include a flexible material, such as metallic or transparent conductive (for example, from indium tin oxide, ITO) traces on a polyester (PET) or other plastic film substrate. The sensor can be placed above the grounding pad, separated by a deformable dielectric material.

In particular, in FIG. 4, there are narrow line conductors 420 and narrow column conductors 430 with wide gaps between each of the rows 420 and between each of the columns 430. The touch sensor 400 includes line conductors 420 above the column conductors 430. Below the column conductors 430 there is a deformable dielectric 110 with a grounding pad 440 below. Column conductors 430 are placed between the lower conductors 420 and the deformable dielectric 110, and the deformable dielectric 100 is placed between the column conductors 430 and the grounding pad 440. From the perspective illustrated in FIG. 4, the line conductors 420 are considered to be on top of other layers shown for the sensor, and the ground 440 is considered to be under other layers shown for the sensor. The predominant capacity in FIG. 4 may be an edge capacity between respective rows 420 and columns 430. Since rows 420 and columns 430 can be approximately coplanar (for example, spacing between rows and columns is relatively small), the edge field can be approximately symmetrical.

FIG. 5 illustrates exemplary edge field strength lines 540 around a line conductor 420 and a column conductor 430 of the touch sensor 400 in FIG. 4. In Fig. 5, the edge field lines 540 can be symmetrical on both sides of the line conductor 420 and the column conductor 430, moreover, on one side of the edge field line 540 come out of the touch sensor 400 to the user, and on the other side of the edge field line 540 go out in the direction away from the user (for example, on the back side and / or towards the display). The edge field on the front of the touch sensor may be disturbed by the user's finger and provide a truly capacitive touch signal, which tends to reduce the measured capacitance. The marginal field on the rear of the sensor can be used by a deformable dielectric 110 and ground plane 440. If the touch sensor is pressed using a non-conductive object, the conductors 420, 430 move to the ground 440, causing a portion of the edge field on this rear side of the sensor to be shorted or at least partially cut off by the ground 440. The current flowing into the transmitting device therefore flows at least partially to the grounding pad 440, which slightly decreases the measured capacitance relative to the capacitance measured when this grounding pad is missing.

6, the measured capacitance 610 is related to the perceived touch force based on the corresponding proximity signal 620 received by the touch sensor. As the user's finger approaches the touch sensor 640, the measured capacity 630 decreases. When the user starts touching the sensor 650, the capacity decreases, and when the user finger is applied with an increased force 660, the capacity decreases further as the sensor approaches the site grounding.

In particular, if the user's finger is pressed very weakly, the capacitance decreases, since the current that flows from the transmitter of the sensor can flow at least partially through the user's finger to the ground, based on at least a partial connection to the ground of the user circuit instead of leaking into the receiver of the sensor. If the user's finger is pressed with increased force, then the measured capacitance decreases even more, since the rows and columns of the sensor can come closer to the ground plane, which causes a separate but additional effect of the forced flow of part of the current into the ground plane instead of the receiving device.

The capacitance measurement illustrated by FIG. 6 is therefore monotonic with respect to the perceived touch force of the user. The monotonic characteristic of the capacitance can enable the conversion of the capacitance function to the movement of the user's finger and / or pressure measurement.

Technologies using frequency can be used to distinguish between reading the capacitance resulting from the user's finger and the capacitance resulting from the force exerted by some other object (for example, a stylus tool, a conductive or non-conductive object). For example, the capacitance relative to the user's finger may vary depending on the frequency, and the capacitance due to the field in the deformable dielectric may remain approximately constant for the frequency. By evaluating capacitive measurements at different frequencies, a determination can be made as to whether the touch sensor is touched by a user's finger or a non-conductive object.

More specifically, in the case of touching the user, a number of effects are provided that can be used to make this distinction to determine the reading of the capacitance resulting from the user's finger (as opposed to the determination of the capacitance resulting from the force exerted by some other object, such as a tool stylus). The measured change in capacitance due to the user's finger can change dramatically (for example, in the region of a coefficient of two or more) with a change in frequency in the practical range. For example, one effect occurs as a result of the impedance between the user and the ground node of the controller circuit, which is not zero, and can be modeled as a capacitance at frequencies of interest. The user may also have capacitive coupling to the ground as a result of being in the vicinity of a grounded touch screen. The user can capacitively ground, for example, through a capacitance of ~ 100 pF. In some cases, the capacity can vary significantly by a factor of at least three to one in any direction, depending, for example, on whether the user is standing barefoot on a concrete floor over a metal deck or in boots with thick soles on the floor created from plywood on dry wooden logs. In a first approximation, the user's connection with the ground can be modeled as a capacitance. Thus, the user can be more effectively grounded at higher frequencies than at lower frequencies, at least because capacitive impedances tend to decrease with increasing frequency.

At lower frequencies, the user may not be grounded so reliably. If the user is grounded less reliably, then instead of flowing current from the transmitting device, through the user's finger and to the ground, part of the current can flow from the transmitting device, through the user's finger and then back to the receiving device, since this impedance path is smaller than the impedance path to ground. In general, this results in a relatively small increase in capacity, which is combined with the reduced capacity described above, resulting in a smaller net change. Since the dielectric constant of human tissues is approximately equal to the dielectric constant of water and thus exceeds the dielectric constant of free space, this effect can, instead of decreasing in some implementations, even lead to an increase in the measured capacitance when the user's finger is present.

Due to the effects, measurements can be made at different excitation frequencies, the user being relatively well grounded at high frequencies, resulting in lower capacitance, and the user is not very well grounded at lower frequencies, resulting in greater capacitance.

For a signal that is sensitive to the strength of the sensor, the capacitance of the force-sensitive sensor refers more to the field in the dielectric of the sensor. The dielectric constant of the deformable dielectric can be taken into account with respect to frequency so that it may not be large to change the capacitance in frequency. The capacitance in a deformable dielectric can be relatively ideal when changing by no more than a few percent in the appropriate frequency range, for example, for the frequency range from about 10 kHz to 1 MHz or more. In some implementations, the materials selected for the dielectric may have a dielectric constant, which does not change with a frequency of more than this value. A side effect can be observed due to the resistance of the conductive paths, which, in combination with the tested tanks, forms a frequency-selective resistive-capacitive (RC) circuit and changes the measured capacitance. If the trace resistance is known, then this RC effect can be calculated and corrected.

Some technologies, in order to distinguish between a truly capacitive touch and a signal of force, may include measuring capacitance at two frequencies, so if the measured capacitance at two frequencies is quite different, there may be an assumption that finger contact probably occurred, and if the measured capacitances at two frequencies are close enough, then there may be an assumption that a force from an object (for example, a stylus tool) is probably applied. For example, a signal generated due to a force may differ from a signal generated due to a truly capacitive touch by scanning at two widely spaced frequencies (for example, 30 kHz and 120 kHz), and note that the first of them should not change more than by several tens of percent, and the second should change dramatically, for example, two or more times. In some implementations, two different frequencies may differ in a ratio of approximately 4: 1.

In some implementations, any capacitive force-sensitive m * n sensor (capacitance from row to column), in which capacitance is measured at several frequencies, can be used to distinguish a truly capacitive touch (due to current through the user's finger) from a force signal .

7, a hybrid touch sensor 700 has highly spaced narrow line conductors 720 on top of wide column conductors 730. Column conductors 730 are placed on deformable dielectric 110, and deformable dielectric 110 is placed on line conductors 740.

The implementation of FIG. 7 shows an example implementation in which a force-sensitive sensor is placed on top of a truly capacitive touch sensor. The truly capacitive sensor assembly of FIG. 7 includes narrow horizontal conductors 720 that are widely spaced from each other, which are located on top of wide column conductors 730. The force-sensitive sensor assembly of FIG. 7 has wide column conductors 730 placed on top of a deformable dielectric 110, which is located on wide line conductors 740, and wide line conductors 740 are often located. The force-sensitive sensor assembly of the hybrid touch sensor 700 can be used to measure the force between the wide column conductors 730 and the line conductors 740, and the truly capacitive touch sensor assembly of the hybrid touch sensor 700 can be used to measure edge fields between the line conductors 720 and wide column conductors 730. The wide column conductors 730 are shared between a force-sensitive sensor and a truly capacitive touch sensor. There may be two separate measurements at each intersection of the respective line conductors 720, 740 and column conductors 730 for the nodes of the force-sensitive sensor and the truly capacitive touch sensor of the hybrid touch sensor 700.

In some implementations, the hybrid touch sensor 700 is a set of frequently arranged lower case conductors 740 from below, then a compressible deformable dielectric 110 above the lower case conductors 740, then often located column conductors 730 above the dielectric 110 and then sparse horizontal conductors 720 over the column conductors 730. Column conductors 730 are placed between the line conductors 720 and the deformable dielectric 100, and the deformable dielectric 100 is placed between the column conductors 730 and line conductors 740. From the perspective illustrated in FIG. 7, line conductors 720 are considered to be on top of other layers shown for the sensor, and line conductors 740 are considered to be under other layers shown for the sensor. By measuring the capacitance of the parallel capacitor plates from frequently spaced rows to frequently spaced columns, a force measurement can be obtained, and by measuring edge capacitance from frequently spaced columns to sparsely spaced rows, a truly capacitive touch signal can be obtained, and touching the user can increase the measured capacitance when measuring force and reducing the measured capacitance when measuring really capacitive touch.

Various implementations described above may be formed from one or more materials or technologies described below. For example, the dielectric can be deformable and can be, for example, soft plastic material, soft silicone, elastomer or other material that has the ability to restore its shape when the deforming force ceases to act. Soft plastic material can be squeezed out of the sides when it is pressed in the area. These materials, although soft, may not compress particularly strongly (for example, their volume may not vary significantly with the applied pressure). This may mean that a reduction in spacing between the plates may occur as a result of a displacement of the dielectric volume rather than an actual decrease in this volume. This can lead, for example, to the formation of a ring shape around the pressed region. This “water bed effect” may mean that the areas of reduced diversity may be displaced by the area of increased diversity to provide volume for the displaced material. For example, when the volume can be maintained when the dielectric is pressed, the pressed region may have a reduced dielectric thickness (e.g., reduced spacing between the line and column conductors), and the regions around the pressed region may have an increased dielectric thickness (e.g., increased spacing between the row and column conductors ) Some other implementations may have opposed areas of increased or decreased capacities depending on the area and properties. In some implementations, the software may be used to determine a truly capacitive touch, and the software may also consider pressed areas with ring shapes of dielectric material around them to determine the force.

In some implementations, a ring shape of an increased capacitance around a point of reduced capacitance can be used to distinguish a signal that results from a force from a signal that arises from a truly capacitive touch. For some of these implementations, the sensor may be a capacitive force-sensitive m * n sensor (row to column capacity) with an incompressible deformable dielectric.

In other implementations, dielectric materials can be used that change in volume when they are pressed (for example, foam containing mainly air or other compressible gas, while the rest of the foam is formed from a flexible material). Other implementations may use dividing point elements. Air in the air gaps can be used as a deformable dielectric, and the contact force can be limited by the stiffness of the sensor, and not the stiffness of the dielectric. The air gap is also optically transparent, and air in the air gap can be compressed. Separating point elements with air gaps may be similar, for example, to elements used in resistive touch screens. Since air can have a very high compression ratio, touch sensors using dividing point elements can read very little force, limited only by the stiffness of the sensor layers.

In some implementations, the ground plane may be a sheet of ITO or another transparent conductor. For example, the touch sensor of FIG. 4 may have an earth ground as an ITO sheet that can connect to the circuit ground. The grounding pad may not form a pattern in some implementations, so the resistance between two points in the grounding pad for a given sheet resistance may be less than when the sheet forms a pattern in a row and column fashion. Such grounding pads can be used in other (rigid and non-force-sensitive) systems to protect the touch sensor from electrical noise generated by the liquid crystal display (LCD). If the touch sensor is used in front of the LCD, then the LCD itself can also be used as a grounding pad. For example, in some implementations, in order to avoid adding another layer (e.g., a ground layer) to the touch sensor kit, the LCD itself can be used as a ground plane, which can include aluminum or other metal wires on the surface of the display, which can simulated as a grounding pad. If the LCD and the touch sensor share ground circuits, then the traces on the LCD can be considered as being in the ground. LCD traces can be excited at a certain voltage, having both a DC component and an AC component, while the DC component may not be taken into account, since the connection to the ground plane is capacitive. The AC component may be important, at least because it can introduce noise into the received signal. For example, the AC component of a signal in metal wires may form a connection with a receiver, although this may be eliminated using some noise reduction techniques. For example, noise reduction technologies can be used to reduce the effects of associated noise, for example, as described in patent applications (US) numbers 12/838419 and 12/838422, which were filed July 16, 2010 and which are fully contained in this document by reference.

In some implementations, the ground plane may be replaced by a sheet of material with a high dielectric constant. For example, if the deformable separation layer is foam or air with separation point elements, then plastic materials (for example, polyester or acrylic material) may have a higher dielectric constant. In these embodiments, the measured capacitance may increase (instead of decreasing) as the edge field penetrates the material with a high dielectric constant. Since the field cannot be shielded by means of a dielectric sheet, these embodiments can enable the dielectric sheet to be placed either behind the touch sensor, as in some implementations of the ground plane, or in front of the touch sensor, in the direction of the user.

In some implementations, capacitances in these systems may be configured to be of the order of about 1 pF in capacitance. Larger capacitances can correspond to higher signal levels, but can also contribute a certain proportion to the time constant of the RC circuit of each capacitance, tested for the resistance of the line and column conductors. This RC-circuit time constant may have such a configuration that the system is not slow compared to the frequency of the excitation voltage, and the excitation signal does not attenuate along the conducting paths and does not generate a large (and spatially varying) measurement error. For sensors designed using ITO, for example, with a sheet resistance of approximately 50 Ohms per unit area, the capacitance can be approximately ~ 1 pF. For sensors made of materials with lower resistance, for example thin metal wires, a larger capacitance value (greater than ~ 1 pF) can be optimally used.

When the force-dependent capacitance is the capacitance of the parallel capacitor plates, as in the touch sensors of FIGS. 1, 2 or 7, the capacitance value can be approximated as C = epsilon * A / d, where A is the capacitor area (slightly less than the square of the matrix step), d is the spacing between the line and column conductors, and epsilon is the dielectric constant of the dielectric material. Therefore, the value of capacitance C can be determined as a function of the thickness of the deformable dielectric material. The matrix may have a pitch of, for example, approximately 5 mm, which corresponds to the approximate size of contact with the fingers. This may mean that spacing between 0.1 mm and 1 mm may form a capacitance of ~ 1 pF. A more accurate estimate of the capacitance value may depend on the pitch of the matrix, which determines the area of the plates, and on the relative dielectric constant of the deformable material, which can be very close to unity for air with dividing point elements or to three or four for elastomers.

When the force-dependent capacitance is an edge capacitance, as described with respect to FIG. 4, for example, there may be other ways to approximate the capacitance values, in addition to simply expressing it in an analytical form, to approximate this capacitance value. The distance in the plane between the horizontal and column conductors can determine the distance normal to the plane that the field is traveling. For example, for a grid of thin wires spaced 2 mm apart, a significant portion of the field may extend by approximately ~ 2 mm. This may mean that as the layers of the sensor approach this ground plane, the ground plane can begin to significantly affect capacitance in the region of 2 mm. Therefore, the thickness of the deformable dielectric can be configured to have this order (for example, between approximately 0.2 mm and 2 mm).

The touch sensor can be made on any number of flexible, non-conductive substrates. One such material includes a polyester (PET) sheet. For example, the touch sensor may be made of a top sheet with horizontal conductors glued to the bottom sheet with column conductors. In some implementations, the two sheets can be bonded using a transparent pressure sensitive adhesive (for example, a product called “Optically Visible Adhesive” (OCA) from 3M ™ St. Paul, Minnesota) or using a UV curing liquid adhesive. In some implementations, conductive line and column conductors can be formed using wide ITO paths or other transparent conductive material. In some implementations, since the resistivity of these materials can be high in order to achieve acceptable resistance, the tracks can be made with the possibility of being wide, of the order of at least ~ 1 mm. The spacing between the line and column conductors can be chosen so that the capacitance of the parallel capacitor plates, when the paths overlap, does not become too large and limits the excitation frequency by increasing the line time constant. In practice, this may correspond to a spacing of, for example, approximately ~ 0.1 mm.

In some implementations, the line and column conductors can also be formed using opaque metal wires that are quite narrow (~ 10 μm) so that they are invisible. In this case, the capacitance component of the parallel plates of the capacitor can be negligible, and two sheets can be placed as close as possible to each other in accordance with mechanical practicality. When the horizontal and column conductors are made of narrow metal wires, a pattern can be configured in which the horizontal and column conductors cross each other several times for each point in the matrix. For example, each line and each column conductor can have three separate wires that are electrically connected to each other. This may mean, for example, that for each point in the matrix, the wires can cross each other 3 * 3 = 9 times. This can have the effect of increasing the total capacity and decreasing the distance that the edge field extends from the touch sensor (and thereby reducing the proper thickness for the deformable dielectric).

In some implementations, the spacing of the sensor and the ground may be approximately ~ 1 mm. The spacing of the line and column conductors may depend on the geometry of the template and may be, when approximating the first order, approximately coplanar. In some implementations, the line conductors used for the top layer of the capacitive touch sensor can be formed sufficiently narrow so that they are approximately 6 μm, so that the capacitance of the parallel capacitor plates in the regions below these narrow line conductors is negligible, and the spacing between these narrow lower case conductors and the underlying column conductor can be set small. If, for example, ITO is used, then there may be a spacing of about ~ 0.1 mm between the line conductors and the underlying column conductors.

In some implementations, sparse line conductors may form a thin film pattern (e.g., approximately hundreds of ITO nanometers) over a polyester substrate (e.g., in the region of ~ 0.1 mm in thickness). Columns can be made in a similar way. Line and column conductors can be glued to each other using transparent glue.

This disclosure describes implementations in which capacitance is measured from each row to each column. There may be a circuit configured to perform this type of measurement, the circuit including transmitting devices and receiving devices in respective columns and rows. In the implementation of this circuit, the columns can be energized by the voltage in the electric power transmission line so that energy flows from the transmitter to the columns, and the receiver can measure the current in rows so that energy flows from the rows to the receiver. Although the designation of one axis as rows and the other as columns is generally arbitrary in this implementation, rows can generally be attached to receivers, and columns can generally be connected to transmitters.

In various implementations, the conductors in the sensor can be configured in a pattern that increases or maximizes the edge capacitance, which can be interrupted by the user's finger to provide the desired signal and minimize additional capacitance between the row and column (for example, the capacitance of parallel capacitor plates), which allows provide constant displacement. Rows and columns in the matrix can be almost coplanar, so although the area of the corresponding capacitor with parallel plates is relatively small, the separation distance is also relatively small, and its capacitance value can be significant. The electrode pattern can also be configured to make the line width as large as possible for a given step, to minimize path resistance, which could otherwise be significant if sensors with a large area are used. The edge capacity can be maximized, for example, by designing the template so that the resulting edge capacity can be set as large as possible. In some implementations of these touch sensors, the unwanted capacitance of the parallel capacitor plates is reduced or minimized by setting the conductive paths narrow where they intersect each other, the resistance can be reduced and minimized by setting the electrode paths relatively wide in other areas.

Other implementations may have other conductor arrangement configurations. In one implementation, for example, one pattern may comprise uniformly spaced straight lines with a pitch identical to the pitch of the electric matrix, straight lines with the step of a finger in the electric matrix, where adjacent lines are interconnected in groups and on-comb patterns to increase the perimeter between the given row and column to increase the marginal field.

Some of the described embodiments of the invention and operations can be implemented in digital electronic circuitry or in computer software, firmware, or hardware, including the structures disclosed in this description and their structural equivalents, or in combinations of one or more of the above. Embodiments of the invention described herein may be implemented as one or more computer programs, i.e. one or more modules of computer program instructions encoded on a computer storage medium for executing or controlling the operation of data processing equipment. Alternatively or in addition, program instructions may be encoded in an artificially generated distributed signal, for example, in a machine-generated electrical, optical or electromagnetic signal, which is formed with the ability to encode information for transmission to a suitable receiving hardware system for execution by a hardware data processing system. Data processing equipment may include a sensor, may form part of a sensor, may form part of a system with a sensor, may be integrated into a system and / or sensor, may form part of receivers, transmitting devices, components and / or logic associated with the sensor or receiving devices and / or transmitting devices, or be any combination of the above. The computer storage medium may be or be included in a computer-readable data storage device, a substrate for a computer-readable data storage device, a matrix or memory device with random or sequential access, or in a combination of one or more of the above. Furthermore, while the computer storage medium is not a distributed signal, the computer storage medium may be a source or destination of computer program instructions encoded in an artificially generated distributed signal. A computer storage medium may also be or be included in one or more separate physical components or media (for example, multiple CDs, disks, or other storage devices).

The operations explained in this detailed description can be implemented as operations performed by a hardware data processing system for data stored on one or more computer-readable data storage devices or received from other sources.

Various hardware systems, devices, and data processing machines can be used as “data processing equipment,” including, as an example, a programmable processor, a computer, an on-chip system, or several or combinations of the above. The equipment may include special-purpose logic, such as FPGA (Field Programmable Gate Array) or ASIC (Specialized Integrated Circuit). The hardware may also include, in addition to hardware, a code that creates a runtime for the computer program in question, for example, code that makes up the processor’s firmware, protocol stack, database management system, operating system, cross-platform runtime, virtual machine or a combination of one or more of the foregoing. Hardware and runtimes can implement many different computing model infrastructures, such as web services, distributed computing, and network parallel computing infrastructures.

A computer program (also known as a program, software, application, script, or code) can be written in any form of a programming language, including compiled or interpreted languages, declarative or procedural languages, and it can be deployed in any form, including including as a stand-alone program or as a module, component, subprogram, object, or other module suitable for use in a computing environment. A computer program may (but should not) correspond to a file in the file system. A program can be saved in a part of a file that stores other programs or data (for example, one or more scripts stored in a markup language document), in one file allocated for the program in question, or in several coordinated files (for example, files that save one or more modules, subroutines or parts of the code). A computer program may be deployed for execution on one computer or on several computers that are located on the same website or distributed across multiple websites and connected through a communication network.

The processes and logical sequences of operations explained in this detailed description can be performed by one or more programmable processors executing one or more computer programs to perform actions by controlling input data and generating output. Processes and logical sequences of operations can also be performed by (and the hardware system can also be implemented as) special-purpose logic, for example, FPGA (Field Programmable Gate Array) or ASIC (Specialized Integrated Circuit).

Processors suitable for executing a computer program include, as an example, general and special purpose microprocessors and any one or more processors of any kind of digital computer. In general, a processor receives instructions and data from read-only memory or random access memory, or from both. The essential elements of a computer are a processor for performing actions in accordance with instructions and one or more storage devices for storing instructions and data. In general, a computer should also include or functionally connect with the ability to receive data or transmit data, or both receive and transmit data to one or more mass storage devices for storing data, for example, magnetic, magneto-optical disks or optical disks . However, the computer does not have to have such devices. In addition, the computer can be integrated into another device, such as, but not limited to, a mobile phone, personal digital assistant (PDA), mobile audio or video player, game console or portable storage device (for example, a flash drive based on a universal serial Bus (USB)). Devices suitable for storing computer program instructions and data include all forms of non-volatile storage device, storage media and storage devices including, as an example, semiconductor storage devices, for example, EPROM, EEPROM and flash memory devices; magnetic disks, such as internal hard drives or removable drives; magneto-optical disks; and CD-ROMs and DVD-ROMs. The processor and the storage device may be supplemented or included in a special-purpose logic circuit.

In order to provide user interaction, embodiments of the invention described in this detailed description may be implemented on a computer having a display device, such as a CRT monitor (cathode ray tube) or an LCD (liquid crystal display), to display information to the user, and a keyboard and pointing device, such as a mouse or trackball, through which a user can provide input to a computer. Other types of devices can also be used to provide user experience; for example, the feedback provided to the user may be any form of sensory feedback, such as visual feedback, acoustic feedback, or tactile feedback; and input from the user may be received in any form, including acoustic, speech, or tactile input. In addition, the computer can interact with the user by sending documents and receiving documents from the device that is used by the user; for example, by sending web pages to a web browser on a user's client device in response to requests received from the web browser.

Although this detailed description contains a lot of specific implementation information, it should not be construed as limiting the scope of the invention or claims, but rather as describing features specific to particular embodiments of a particular invention. Certain features, which are explained in this detailed description in the context of individual embodiments, can also be implemented in combination in one embodiment. Conversely, various features that are described in the context of one embodiment may also be implemented in several embodiments individually or in any suitable subcombination. In addition, although the features may be described above as operating in certain combinations and even initially defined in the claims, essentially one or more of the features of the claimed combination may in some cases be excluded from the combination, and the claimed combination may be directed to a sub-combination or to change of subcombination.

Similarly, although the operations are illustrated in the drawings in a specific order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations must be performed in order to achieve the desired results. Under certain circumstances, multitasking and parallel processing may be advantageous. In addition, the separation of the various system components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described software components and systems, in general, can be integrated into one software product or completed with several software products.

Thus, specific embodiments of the invention are described. Other embodiments are within the scope of the appended claims. In some cases, the actions set forth in the claims may be performed in a different order and at the same time achieve the desired results. In addition, the processes illustrated in the accompanying drawings do not necessarily require the particular order shown or sequential order in order to achieve the desired results. In certain implementations, multitasking and parallel processing may be useful.

Claims (40)

1. A capacitive touch sensor containing:
a first matrix of conductors arranged in rows, wherein the conductors in the first matrix are arranged substantially parallel to each other;
the second matrix of conductors arranged in columns, wherein the columns of conductors in the second matrix are arranged substantially parallel to each other, the conductors in the second matrix being under the first matrix of conductors, and the columns of conductors in the second matrix being arranged in a direction that is essentially perpendicular to the direction of the rows of conductors in the first matrix;
a sheet containing a deformable dielectric material, wherein the sheet is under the second matrix of conductors; and
grounding pad below the sheet
the first and second matrices are configured to form an electric field with electric field strength lines that go in the first direction to the sensor user and in the second direction to the ground plane. 2. The sensor according to claim 1, in which:
the width of the conductors, measured in one row in the first matrix, is less than the separation distance between the respective conductors, measured between the adjacent edges of two adjacent rows of the first matrix, and
the width of the conductors, measured in one column in the second matrix, is less than the separation distance between the respective conductors, measured between the adjacent edges of two adjacent columns in the second matrix. 3. The sensor according to claim 1, in which the ground plane is placed with the ability to at least partially break off some of the lines of the electric field, going in the second direction. 4. The sensor according to claim 1, wherein the sensor is configured to detect interruption in electric field strength lines in a first direction. 5. The sensor according to claim 4, wherein the sensor is configured to detect an interruption in the electric field strength lines resulting from an object that is located close to the sensor in the electric field lines of the first direction. 6. The sensor according to claim 5, in which the object is part of the human body of the sensor user. 7. The sensor according to claim 6, in which the object is a finger of the user of the sensor. 8. The sensor according to claim 6, wherein the sensor comprises transmitting devices and receiving devices, the sensor being configured to
transmit using transmitting devices signals at at least two different frequencies in the first or second matrix of conductors;
receive signals using at least two different frequencies in the other of the first or second matrix of conductors with the help of receiving devices;
evaluate the capacitance value at each of these two different frequencies using the received signals;
determine that the object is part of the human body of the user if the estimated capacitance values at two frequencies differ two or more times; and
determine that the object is not an object that allows the formation of a truly capacitive touch signal, and that the activation of the sensor is determined by the measured force if the estimated capacitance values at two frequencies do not differ two or more times. 9. The sensor according to claim 1, wherein
the sensor is configured to receive external force from touching or pressing the sensor,
the sensor is configured to compress at least the conductors in the first and second matrices in the direction of the ground plane to receive an external force, and
the sensor is configured to reduce the capacity of the sensor when an external force is applied to the sensor. 10. The sensor according to claim 9, wherein the sensor has a capacitance characteristic in which the level of the measured capacitance decreases monotonously from the moment the object is placed near the sensor to the moment the object touches and presses the sensor. 11. The sensor of claim 10, in which the ground plane contains a sheet of indium oxide and tin (ITO) or a transparent conductor. 12. The sensor according to claim 1, in which the ground plane contains wires or metal formed on a liquid crystal display (LCD). 13. The sensor according to claim 1, wherein the sensor has a configuration in which one of the grounding pad or the second sheet of material is formed under the sheet containing the deformable dielectric material, while the second sheet of material has a dielectric constant that is higher than the dielectric constant of the deformable dielectric material . 14. The sensor according to claim 1, wherein the sensor has a configuration in which either a ground plane is formed under the sheet containing the deformable dielectric material, or a second sheet of material is formed above the sheet containing the deformable dielectric material, while the second sheet of material contains a dielectric constant , which exceeds the dielectric constant of the sheet of deformable dielectric material. 15. The sensor according to claim 1, wherein the sensor contains indium tin oxide (ITO) on a polyester sheet (PET). 16. The sensor according to claim 1, wherein the sensor contains opaque metal tracks on a polyester sheet (PET) or a plastic substance. 17. The sensor according to claim 1, in which the conductors contain a transparent conductive material placed in the template so as to form an edge electric field between the first and second matrixes of conductors. 18. The sensor according to 17, in which the rows and columns contain diamond-shaped patterns in disjoint locations of conductors in the first and second. 19. The sensor according to claim 1, in which the conductors in the second matrix are located between the first matrix of conductors and the deformable dielectric, while the deformable dielectric is located between the conductors in the second matrix and the ground plane. 20. A capacitive touch sensor containing:
the first matrix of conductors placed in rows, while the rows of conductors in the first matrix are arranged essentially parallel to each other, while the width of the conductors, measured in one row in the first matrix, is less than the separation distance between the respective conductors, measured between adjacent edges of two adjacent rows of the first matrix;
the second matrix of conductors arranged in columns, wherein the columns of conductors in the second matrix are arranged substantially parallel to each other, with the conductors in the second matrix being under the conductors in the first matrix, while the columns of conductors in the second matrix are arranged in a direction that is essentially perpendicular to the direction of the rows of conductors in the first matrix, and the width of the conductors, measured in one column in the second matrix, exceeds the separation distance between the corresponding conductor and as measured between the adjacent edges of two adjacent columns in the second matrix;
a sheet containing a deformable dielectric material, wherein the sheet is under the second matrix of conductors; and
the third matrix of conductors arranged in rows, with the rows of conductors in the third matrix being arranged substantially parallel to each other, with the conductors in the third matrix being under the sheet, and the rows of conductors in the third matrix being arranged in a direction that is essentially perpendicular to the direction of the columns of conductors in the second matrix, and the width of the conductors, measured in one row of the third matrix, exceeds the separation distance between the respective conductors, measured between adjacent bubbled edges of two adjacent rows of the third matrix. 21. The sensor according to claim 20, wherein
the sensor contains a force-sensitive sensor and a truly capacitive touch sensor,
the capacitive touch sensor contains conductors of the first and second matrices,
the force-sensitive sensor contains conductors of the second and third matrices and a sheet containing a deformable dielectric material,
a force sensitive sensor is configured to first measure the first capacitance for the capacitance of the parallel capacitor plates between the intersections of the conductors of the second and third arrays, and
a truly capacitive touch sensor is configured to second measure a second capacitance associated with an edge electric field between the first and second arrays of conductors. 22. The sensor according to claim 20, wherein
the sensor is configured to determine whether or not an object is located close to touching the sensor by means of an edge electric field,
the sensor is further configured to determine whether or not the object applies force to the sensor or not,
the sensor is configured to reduce the level of the second capacitance as the object approaches the touch of the sensor, and
the sensor is configured to raise the level of the first capacitance as the object touches and applies force to the sensor. 23. The sensor according to claim 20, wherein the sensor comprises indium tin oxide (ITO) on a polyester sheet (PET). 24. The sensor according to claim 20, wherein the sensor contains opaque metal tracks on a polyester sheet (PET) or a plastic substance. 25. The sensor according to claim 20, in which the conductors contain a transparent conductive material placed in the template so as to form an edge electric field between the first and second matrixes of conductors. 26. The sensor according to claim 20, in which the conductors in the second matrix are located between the first matrix of conductors and the deformable dielectric, while the deformable dielectric is placed between the conductors in the second matrix and the third matrix of conductors. 27. A method of measuring in a capacitive touch sensor, wherein the sensor comprises a first matrix of conductors arranged in rows, a second matrix of conductors arranged in columns that are substantially perpendicular to the rows of conductors in the first matrix, at least one transmitter connected with conductors in one of the first and second matrix of conductors, and at least one receiving device connected to conductors in another of the first and second matrix of conductors, the method comprising the steps of where:
using at least one transmitter, transmit signals at at least two different frequencies that form an electric field between at least one of the conductors in the first matrix and at least one of the conductors in the second matrix, the first and second matrices being made with the ability to form an edge electric field that goes towards the sensor user, and to provide the ability to detect interruption of the electric field resulting from an object that is placed It is located near the sensor;
receiving at least two different frequencies with at least one receiver;
evaluating the capacitance value at each of these two or more different frequencies using the received signals;
determining whether or not the estimated capacitance value at each of two or more frequencies differs by about two or more times;
calculating the difference or ratio between the estimated capacitance values;
comparing the difference or ratio with a threshold value; and
determine whether or not the object allows the formation of a truly capacitive touch signal, and whether or not activation of the sensor is determined by the measured force, based on the results of comparing the difference or ratio between the estimated capacitance values at two or more frequencies with a threshold value. 28. The method according to item 27, wherein the method comprises determining that the object is part of the human body of the user of the touch sensor, if the estimated capacitance values at two frequencies differ approximately two or more times. 29. The method according to p, in which part of the human body is a finger. 30. The method according to item 27, in which:
the conductors in the first matrix are arranged essentially parallel to each other,
the conductors in the second matrix are arranged essentially parallel to each other,
the conductors in the second matrix are under the conductors in the first matrix,
the width of the conductors, measured in one row in the first matrix, is less than the separation distance between the respective conductors, measured between the adjacent edges of two adjacent rows of the first matrix, and
the width of the conductors, measured in one column in the second matrix, is less than the separation distance between the respective conductors, measured between the adjacent edges of two adjacent columns in the second matrix. 31. The method according to clause 30, in which the sensor further comprises:
a sheet containing a deformable dielectric material, wherein the sheet is under the second matrix of conductors; and
grounding pad under the sheet. 32. The method according to item 27, in which two different frequencies differ by a ratio of approximately four to one. 33. The method according to item 27, in which the sensor contains a sensor truly capacitive touch. 34. The method according to item 27, in which:
the sensor contains a force-sensitive sensor and a truly capacitive touch sensor,
a truly capacitive touch sensor contains conductors in the first and second arrays, and
The force-sensitive sensor comprises conductors in a second matrix, conductors in a third matrix, and a sheet containing a deformable dielectric material. 35. The method according to clause 34, in which:
the conductors in the first matrix are arranged essentially parallel to each other,
the width of the conductors, measured in one row in the first matrix, is less than the separation distance between the respective conductors, measured between the adjacent edges of two adjacent rows of the first matrix;
the conductors in the second matrix are arranged essentially parallel to each other,
the conductors in the second matrix are under the conductors of the first matrix,
the width of the conductors, measured in one column in the second matrix, exceeds the separation distance between the corresponding conductors in the columns, measured between the adjacent edges of two adjacent columns in the second matrix;
the sheet is under the conductors of the second matrix;
the conductors of the third matrix are placed in rows,
the conductors in the third matrix are arranged essentially parallel to each other,
the conductors in the third matrix are under the sheet,
the conductors in the third matrix are arranged in a direction that is substantially perpendicular to the direction of the conductors in the second matrix, and
the width of the conductors, measured in one row in the third matrix, exceeds the separation distance between the corresponding conductors, measured between the adjacent edges of two adjacent rows in the third matrix. 36. The method according to item 27, in which:
said two different frequencies comprise a first frequency and a second frequency, and
the first frequency is higher than the second frequency, and
the method further comprises receiving signals for a second frequency in at least one receiving device that have a higher current than signals received for a first frequency. 37. The method according to item 27, in which the sensor contains indium and tin oxide (ITO) on a polyester sheet (PET). 38. The method according to item 27, in which the sensor contains opaque metal paths on a polyester sheet (PET) or a plastic substance. 39. The method according to item 27, in which the conductors contain a transparent conductive material placed in the template so as to form an edge electric field between the first and second matrices. 40. The method according to § 39, in which the rows and columns contain diamond-shaped patterns in disjoint locations of the conductors of the first and second matrices.

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