Abstract: A method of processing a number of force values is described. Each force value corresponds to a sensor location. The sensor locations are spaced apart along a direction. The method includes receiving the force values (S11). The method also includes determining whether the force values include one or more candidate peaks (S12). Each candidate peak corresponds to a local maximum of the force values. The method also includes, in response to at least one candidate peak exceeds a minimum force threshold (S13), interpolating the force values and estimating a number of peak coordinates and corresponding peak force values based on the interpolated force values and the candidate peaks (S14) which exceed the minimum force threshold.

Abstract: An apparatus (2, 22) is described which includes a touch panel (1, 21). The touch panel (1, 21) includes a layer of piezoelectric material (4) disposed between a number of sensing electrodes (5, 23, 24) and at least one counter electrode (6). The apparatus (2, 22) also includes a touch controller (3) connected to the touch panel (1, 21). The touch controller (3) is configured to determine, in response to receiving piezoelectric signals (7) from one or more of the sensing electrodes (5, 23, 24), a location (9) and an applied force (10) corresponding to a user interaction (11) with the touch panel (1, 21). The touch controller (3) is configured to determine a capacitance value (20) of one or more of the sensing electrodes (5). The touch controller is configured to operate in a force-based mode, a capacitance-based mode or a mixed force-capacitance mode depending on the type of input received.

Abstract: An apparatus (73) for processing signals from a touch panel (10) is described. The touch panel (10) includes a layer of piezoelectric material (16) disposed between a number of sensing electrodes (14, 20) and at least one common electrode (15). The apparatus (73) includes a capacitive touch controller (69) for connection to the sensing electrodes (14, 20). The apparatus (73) also includes a switch network (74) including a number of inputs for connection to some or all of the sensing electrodes (14, 20), and an output connected to system ground or a common mode voltage (VCM). The apparatus (73) also includes a second circuit (24, 44) for connection to the at least one common electrode (15) and configured to generate, based on signals received from the at least one common electrode, a second pressure signal (30) indicative of a total pressure applied to the touch panel (10).

Abstract: A force-sensing touch panel (31) is described which includes a layer structure stacked in a thickness direction between first and second surfaces. The layer structure includes from first surface to second surface, a number of first electrodes (7) and a number of second electrodes (8), a layer of piezoelectric material (9), and a number of third electrodes (30). The first and second electrodes (7, 8) are configured to define a coordinate system for sensing a location of a force applied to the touch panel in a plane perpendicular to the thickness direction. The third electrodes (30) are configured such that signals received from the first, second and third electrodes (7, 8, 30) enable determining unique locations corresponding to two or more forces applied to the touch panel (31) concurrently.

Abstract: An apparatus (73) for processing signals from a touch panel (10) is described. The touch panel (10) includes a layer of piezoelectric material (16) disposed between a number of sensing electrodes (14, 20) and at least one common electrode (15). The apparatus (73) includes a capacitive touch controller (69) for connection to the sensing electrodes (14, 20). The apparatus (73) also includes a switch network (74) including a number of inputs for connection to some or all of the sensing electrodes (14, 20), and an output connected to system ground or a common mode voltage (VCM). The apparatus (73) also includes a second circuit (24, 44) for connection to the at least one common electrode (15) and configured to generate, based on signals received from the at least one common electrode, a second pressure signal (30) indicative of a total pressure applied to the touch panel (10).

Abstract: A device for touch panel pressure detection includes a plurality of first input/output terminals for a projected capacitance touch panel. The projected capacitance touch panel includes a layer of piezoelectric material disposed between a plurality of sensing electrodes and a common electrode. The device also includes one or more amplifiers. Each amplifier has an inverting input, a non-inverting input and an output. The non-inverting input of the or each amplifier is configured to be switched between a common mode voltage and a capacitance measurement signal. The inverting input of the or each amplifier is configured to drive an input/output terminal based on the capacitance measurement signal. The amplifier is configured such that, when an input/output terminal is connected to a sensing electrode, the amplifier output varies in dependence upon a pressure applied to the touch panel.

Abstract: A device (1) includes a body (2) and a touch panel (3) supported by, integrated with, or underlying the body (2). The touch panel (3) includes a layer of piezoelectric material (5) disposed between a plurality of first electrodes (6) and at least one second electrode (7). The device (1) also includes at least one second piezoelectric input region (8) supported by, integrated with, or underlying a portion of the body (2) which does not correspond to the touch panel (3). The device (1) is configured to receive user input using the touch panel (3) and/or at least one piezoelectric input region (8).

Abstract: A touch sensor (1) for combined capacitive touch and force sensing is described. The touch sensor (1) includes number plurality of first electrodes (4) and a number of second electrodes (5). The second electrodes (5) are insulated from the first electrodes (4). The first and second electrodes (4, 5) form a grid for capacitive touch sensing. The touch sensor (1) also includes a transparent cover (6). The touch sensor (1) also includes a transparent piezoelectric film (3) arranged between the transparent cover (6) and the first and second electrodes (4, 5). The touch sensor (1) also includes a patterned counter electrode (8) disposed between the transparent piezoelectric film (3) and the transparent cover (6). The patterned counter electrode (8) is a conductive grid formed from the union of plurality of counter electrode line elements (9). A pitch of the counter electrode line elements (9) is larger than a pitch of the first electrodes (4) and/or second electrodes (5).

Abstract: An apparatus for processing signals from a touch panel. The touch panel includes a layer of piezoelectric material disposed between a number of sensing electrodes and one or more common electrodes. The apparatus includes a capacitive touch controller for connection to the sensing electrodes and a switch network including inputs for connection to the sensing electrodes and an output connected to system ground or a common mode voltage. The apparatus includes a circuit for connection to the common electrodes and to generate, for each common electrode, a corresponding pressure signal indicative of a pressure applied to the touch panel proximate to that common electrode. The apparatus includes a controller to control the switch network to couple any connected sensing electrodes to system ground or the common mode voltage during a pressure measurement period, and to sample the one or more second pressure signals during the pressure measurement period.

Abstract: A method includes receiving (S1), from a touch panel (1), force values (23) corresponding to a plurality of piezoelectric sensors (5,6, 7), Each piezoelectric sensor corresponds to a physical location (xm, yn) on the touch panel. The method also includes receiving (S2) one or more user touch locations corresponding to user touches, The method also includes excluding (S5) all force values (23) corresponding to physical locations within a distance of a user touch location, and setting the remaining force values (23) as valid force values (S5). The method also includes interpolating and/or extrapolating (S6), based on the valid force values, one or more reconstructed force values (25) corresponding to same physical locations (xm, yn) as the respective excluded force values (23).

Abstract: A method of processing a number of force values is described. Each force value corresponds to a sensor location. The sensor locations are spaced apart along a direction. The method includes receiving the force values (S11). The method also includes determining whether the force values include one or more candidate peaks (S12). Each candidate peak corresponds to a local maximum of the force values. The method also includes, in response to at least one candidate peak exceeds a minimum force threshold (S13), interpolating the force values and estimating a number of peak coordinates and corresponding peak force values based on the interpolated force values and the candidate peaks (S14) which exceed the minimum force threshold.

Abstract: An apparatus for combined capacitance and pressure sensing is described. The apparatus includes a multiplexer (75) having a plurality of inputs (76) and an output (F), a touch panel (29), and a front end module (3). The touch panel includes a layer structure (5; FIG. 15) comprising one or more layers, each extending perpendicularly to a thickness direction, the one or more layers including a layer of piezoelectric material (10; FIG. 15), the layer structure having first (6) and second (7; FIG. 15) opposite faces, and the layer(s) arranged between the first and second faces such that the thickness direction of each layer is perpendicular to the first and second faces. The touch panel also includes a plurality of first electrodes (8) disposed on the first face, each first electrode connected to a respective input of the multiplexer. The touch panel also includes at least one second electrode (9) disposed on the second face.

Abstract: An apparatus (22) for processing signals from a touch panel (10) is described. The touch panel (10) includes a layer of piezoelectric material (16) disposed between a plurality of sensing electrodes (14, 20) and at least one common electrode (15). The apparatus (22) includes a first circuit (23) for connection to the plurality of sensing electrodes (14, 20). The first circuit (23) is configured to generate a plurality of first pressure signals (29). Each first pressure signal (29) corresponds to one or more sensing electrodes (14, 20) and is indicative of a pressure acting on the touch panel (10) proximate to the corresponding one or more sensing electrodes (14, 20). The apparatus also includes a second circuit (24) for connection to the at least one common electrode (15). The second circuit (24) is configured to generate a second pressure signal (30) indicative of a total pressure applied to the touch panel (10).

Abstract: An apparatus (22) for processing signals from a touch panel (10) is described. The touch panel (10) includes a layer of piezoelectric material (16) disposed between a plurality of sensing electrodes (14, 20) and at least one common electrode (15). The apparatus (22) includes a first circuit (23) for connection to the plurality of sensing electrodes (14, 20). The first circuit (23) is configured to generate one or more first pressure signals (29). Each first pressure signal (29) corresponds to one or more sensing electrodes (14, 20) and is indicative of a pressure acting on the touch panel (10) proximate to the corresponding one or more sensing electrodes (14, 20). The apparatus also includes a second circuit (24) for connection to the at least one common electrode (15). The second circuit (24) is configured to generate a second pressure signal (30) indicative of a total pressure applied to the touch panel (10).

Abstract: An apparatus (73) for processing signals from a touch panel (10) is described. The touch panel (10) includes a layer of piezoelectric material (16) disposed between a number of sensing electrodes (14, 20) and at least one common electrode (15). The apparatus (73) includes a capacitive touch controller (69) for connection to the sensing electrodes (14, 20). The apparatus (73) also includes a switch network (74) including a number of inputs for connection to some or all of the sensing electrodes (14, 20), and an output connected to system ground or a common mode voltage (VCM). The apparatus (73) also includes a second circuit (24, 44) for connection to the at least one common electrode (15) and configured to generate, based on signals received from the at least one common electrode, a second pressure signal (30) indicative of a total pressure applied to the touch panel (10).

Abstract: A device (116) for processing signals from a projected capacitance touch panel (43) is described. The projected capacitance touch panel (43) includes a layer of piezoelectric material (9) disposed between a number of sensing electrodes (7, 27) and at least one counter electrode (8). The device (116) includes a capacitive touch controller (84) having a number of measurement ports (122). The device (116) also includes a number of charge amplifiers (123). The device (116) also includes a number of terminals (C1, . . . , C5, D1, . . . , D5) for connection to the sensing electrodes (7, 27) of the projected capacitance touch panel (43). Each terminal (C1, . . . , C5, D1, . . . , D5) is connected to one of the measurement ports (122). Each terminal (C1, . . . , C5, D1, . . . , D5) is also connected to an input of one of the charge amplifiers (123) via a corresponding switch (SW) of a number of switches (117a, 117b).

Abstract: A device (48) for combined capacitance and pressure measurements includes a number of first input/output terminals for a projected capacitance touch panel, wherein the projected capacitance touch panel includes a layer of piezoelectric material disposed between a plurality of first electrodes and at least one second electrode. The device also includes a plurality of second input/output terminals for a capacitive touch controller. The device also includes a plurality of separation stages, each separation stage connecting at least one first input/output terminal to a corresponding second input/output terminal, and each separation stage including a first frequency-dependent filter for filtering signals between first and second input/output terminals.

Abstract: A method includes receiving (S1), from a touch panel (1), force values (23) corresponding to a plurality of piezoelectric sensors (5,6, 7). Each piezoelectric sensor corresponds to a physical location (xm, yn) on the touch panel. The method also includes receiving (S2) an identification of which, if any, of the force values (23) are influenced by coupling to external electric fields. The method also includes, in response to one or more force values (23) being identified as influenced by coupling to external electric fields (S3), setting the corresponding force values (23) as excluded force values (S5), and setting the remaining force values (23) as valid force values (S5). The method also includes interpolating and/or extrapolating (S6), based on the valid force values, one or more reconstructed force values (25) corresponding to same physical locations (xm, yn) as the respective excluded force values (23).

Abstract: Apparatus (22) for processing signals from a touch panel (10) is described. The touch panel (10) includes a layer of piezoelectric material (16) disposed between a plurality of sensing electrodes (14, 20) and at least one common electrode (15). The apparatus (22) includes a first circuit (23) for connection to the plurality of sensing electrodes (14, 20). The first circuit (23) is configured to generate a plurality of first pressure signals (29). Each first pressure signal (29) corresponds to one or more sensing electrodes (14, 20) and is indicative of a pressure acting on the touch panel (10) proximate to the corresponding one or more sensing electrodes (14, 20). The apparatus (22) also includes a second circuit (24) for connection to the at least one common electrode (15). The second circuit (24) is configured to generate a second pressure signal (30) indicative of a total pressure applied to the touch panel (10).

Abstract: A device (42) is provided for processing signals (10) from a projected capacitance touch panel (43), the touch panel (43) including a layer of piezoelectric material (9) disposed between a plurality of first electrodes (7, 27) and at least one second electrode (8). The device is configured, in response to receiving input signals (10) from a given first electrode (7, 27), to generate a pressure signal (15a, 15b) indicative of a pressure applied to the touch panel (43) proximate to the given first electrode (7, 27) and a capacitance signal (54a, 54b) indicative of a capacitance of the given first electrode (7, 27). The device (42) includes an amplifier (52) configured to generate an amplified signal (14a, 14b) based on the input signals (10).