Sensors and how to operate them

Abstract

A capacitive sensor comprising a plurality of read lines and an array of sensor pixels, each sensor pixel being connected to a read line and equipped with a capacitive sensing electrode, is configured to acquire a signal from a first read line indicating the charge at the capacitive sensing electrode of at least one sensor pixel connected to the first read line, and to maintain the second read line at a read reference voltage while acquiring the signal from the first read line.

Description

[Technical Field]

[0001] This disclosure relates to the field of sensors and methods for operating sensors. In particular, this disclosure may apply to the field of capacitive sensors, for example, capacitive biometric skin-contact sensors and methods for operating such sensors. [Background technology]

[0002] International Publication Nos. 2020 / 178605 and 2022 / 043699, published in the PCT, disclose different examples of capacitive biometric skin-contact sensors. These sensors are operable to acquire capacitive measurements over a large area of ​​the sensor array. Based on these capacitive values, biometric data may be acquired about a user in contact with the sensor. For example, the difference between ridges and valleys in a user's skin contours may be identified based on the difference in capacitance measured across the sensor array. The sensor may implement biometric authentication by comparing the acquired distribution of skin contours with a known distribution of skin contours. For example, the sensor may be a fingerprint sensor capable of identifying a user based on the user's fingerprint. With respect to both prior art publications, the specific sensor pixel designs disclosed herein are selected to provide a high signal-to-noise ratio for measurements acquired using the sensor pixels.

[0003] This disclosure aims to reduce noise associated with prior art sensors. In particular, the subject matter disclosed herein may further increase the signal-to-noise ratio for capacitive sensors, such as those of the type disclosed in the aforementioned PCT publication. [Overview of the project]

[0004] The aspects of this disclosure are described in the independent claims, and optional features are described in the dependent claims. The aspects of this disclosure may be provided in relation to one another, and features of one aspect may be applied to other aspects.

[0005] In one embodiment, a capacitive sensor is provided comprising a plurality of read lines and an array of a plurality of sensor pixels, each of which is connected to a read line and includes a capacitive sensing electrode. The sensor is configured to acquire a signal from a first read line indicating the charge at the capacitive sensing electrode of at least one sensor pixel connected to the first read line, and to maintain a second read line at a read reference voltage while acquiring the signal from the first read line.

[0006] In one embodiment, a capacitive sensor is provided comprising a plurality of supply lines and an array of a plurality of sensor pixels, each sensor pixel being connected to a supply line and having a capacitive sensing electrode. The sensor is configured to acquire a signal indicating the charge at the capacitive sensing electrode of at least one sensor pixel connected to a first supply line, and to maintain a second supply line at a supply reference voltage while acquiring the said signal from at least one sensor pixel connected to the first supply line.

[0007] In both of the above embodiments, the conductive lines of the sensor array (readout lines and / or supply lines) are maintained at a reference voltage while signals are acquired from the sensor pixels of the array. As a result, since the relevant conductive lines are at a reference voltage, there may be a known value of any capacitive coupling between the pixels and the signals acquired from each of the relevant conductive lines (readout and / or supply). For example, the signal from the sensor pixel may also be a readout signal carried on a readout line of the sensor array, and the readout line may be arranged to capacitively couple with the supply lines and / or readout lines adjacent to it. By maintaining the adjacent supply lines and / or readout lines at a reference voltage, the amount of capacitive coupling between the readout line and the lines adjacent to it is no longer an unknown amount. In some examples, the adjacent conductive lines may be maintained at the same voltage as the readout line from which the readout signal is acquired. In this case, there may be no capacitive coupling between the readout line and the conductive lines adjacent to it, or it may be minimal.

[0008] The two embodiments are provided in combination, and both the supply line and the read line may be maintained at their respective reference voltages while signals are acquired from the sensor pixels. For example, the sensor may have multiple supply lines, with each sensor pixel connected to a supply line, and at least one sensor pixel connected to a first read line may also be connected to a first supply line, and the sensor may be configured to maintain the second supply line at a supply reference voltage while signals are acquired from the first read line. The supply reference voltage may be the same as the read reference voltage. For example, the sensor may be configured to connect the supply line and the read line to a reference voltage source (which maintains both sets of lines at a reference voltage).

[0009] Each readout line may have a corresponding supply line connected to the same sensor pixels as the sensor pixels of the same readout line. The sensor pixels may be arranged in different aggregates of sensor pixels, where each aggregate of sensor pixels has its own supply line and / or readout line. The supply / readout lines may be connected to each of the sensor pixels in the aggregate. For example, the sensor array may include a plurality of rows of sensor pixels and a plurality of columns of sensor pixels. Each aggregate of sensor pixels (e.g., each column) may have its own supply line and readout line. The sensor may be configured to activate a part (e.g., a column) of an aggregate of the sensor array and deactivate other (e.g., the remaining) aggregates (e.g., columns) of the sensor array. The activated aggregate (e.g., column) may include at least one sensor pixel from which a signal indicating the charge in the capacitive sensing electrode of at least one sensor pixel is acquired. The supply line for each activated aggregate (e.g., column) may be connected to a supply voltage source. The readout line for each activated aggregate (e.g., column) may be connected to a processing channel of the read / write input circuit of the sensor. The supply line for each deactivated aggregate (e.g., column) may be connected to a (supply) reference voltage source. The readout line for each deactivated aggregate (e.g., column) may be connected to a (readout) reference voltage source. For example, the deactivated supply line and the deactivated readout line associated with the same deactivated supply line may be connected to a common reference voltage source. Maintaining a conductive line (e.g., a readout or supply line) at a reference voltage while a readout signal is being acquired may include connecting the conductive line to a reference voltage source, e.g., such that the conductive line is connected to the reference voltage source while the readout signal is being acquired.

[0010] In other words, the sensor may be configured to maintain any non-operating supply line and / or readout line of the sensor array at a reference voltage. The sensor may be configured to maintain the non-operating supply lines and / or readout lines of the sensor array at a reference voltage while a readout signal is being acquired from sensor pixels connected to the operating supply line and / or readout line. The sensor is configured to control its operation such that a portion of the readout / supply lines of the sensor array is activated and a portion is deactivated. As described above, since the non-operating lines are maintained at a known reference voltage (which may be the same as or close to the voltage of the sensor's readout signal processing circuit, for example), any capacitive coupling between the operating readout line and the non-operating supply / readout lines may be known (for example, any such capacitive coupling may be minimal, such as zero).

[0011] The first readout line and the second readout line may be switchably connected to a single channel of the sensor's readout circuit. Three or more readout lines may be switchably connected to a single channel of the sensor's readout circuit. The sensor may be configured to multiplex signals from two or more identical readout lines onto a single channel. The single channel may be a signal processing channel of the sensor's readout circuit. The readout circuit may be configured to obtain a digital representation of the charge stored in the capacitive sensing electrodes based on the readout signal provided to the processing channel of the readout circuit. The readout lines may be arranged in groups, and each group containing a plurality of readout lines has one associated processing channel. The sensor may be configured to connect only one of the readout lines in a group to the processing channel at a time. The sensor is configured to select, at any given time, which readout line is connected to the processing channel. The sensor may simply be configured to activate only one readout line (and the associated supply line) per group of readout lines. The sensor may connect the active readout lines in a group to the processing channel. The sensor may connect the remaining non-active readout lines in a group to a readout reference voltage source.

[0012] The sensor may be configured to selectively connect each read line to either (i) a read reference voltage source that maintains the read line at a read reference voltage, or (ii) a sensor read circuit that processes the signals received from the read line. The sensor may also be configured to selectively connect each supply line to either (i) a supply reference voltage source that maintains the supply line at a supply reference voltage, or (ii) a pixel supply voltage source that provides electrical energy to the sensor pixels connected to the supply line. The read reference voltage source and the supply reference voltage source may be the same (e.g., a common reference voltage source). The sensor may have multiple selection lines, each selection line associated with a read line and a corresponding supply line. The sensor may be configured to control the application of a selection signal to each selection line in order to control the connections between the read line and the supply line associated with that selection line. The application of a selection signal to the selection line associated with the first read line and the first supply line may be done by (i) connecting the first read line to a read circuit and (ii) connecting the first supply line to a pixel supply voltage source. The application of a selection signal to the selection line associated with the second read line and the second supply line may be done by (i) connecting the second read line to a read reference voltage source and (ii) connecting the second supply line to a supply reference voltage source.

[0013] In other words, the sensor may be configured to selectively activate and deactivate read lines and supply lines by applying a signal to the associated selection line. For example, each supply line and the read line associated with that supply line may have an associated selection line. The sensor may be configured such that the application of a selection signal (e.g., voltage) to the selection line can activate any supply line and read line associated with that selection line. The application of a selection signal to the selection line can deactivate any supply line and read line not associated with that selection line. Each selection line may be associated with one supply line and one read line for each group of read lines. The application of a selection signal to the selection line can activate one read line (and its associated supply line) for each group of read lines (and deactivate the remaining supply / read lines within each group, for example).

[0014] The first read line may be adjacent to the second read line. The first supply line may be adjacent to the second supply line. The read reference voltage may be selected to correspond to the voltage of the sensor's read circuit. The read reference voltage may be the same as, or close to, the voltage of the read circuit (for example, the read reference voltage may be within a threshold range of the read circuit voltage, e.g., 1V, 0.5V, 0.25V, or 0.1V). The read reference voltage for the second line may be the same as the voltage for the first read line. The sensor array may have multiple scan lines. Each sensor pixel may be connected to a scan line that receives a scan signal. The scan signal may be applied to activate the sensor pixel. For example, each operating sensor pixel may receive a scan signal via the scan line to which it is connected, receive a supply voltage from the supply line to which it is connected, and output a read signal to the read line to which it is connected, the read line being connected to the processing channel of the sensor's read circuit. The capacitive sensor may also include a capacitive touch sensor.

[0015] The sensor may comprise an array of sensor pixels, each of which may include one or more thin-film transistors ("TFTs") and a capacitive sensing electrode. The sensor pixels may be arranged in an active matrix array, and the sensor may be operable to process each pixel by applying a scanning signal to it. Each processed pixel may also receive a supply voltage from a supply line. Each processed pixel may output a readout signal to a readout line. For each sensor pixel, the readout signal may indicate the proximity of a conductive material to be detected to the capacitive sensing electrode of that sensor pixel. The sensor may comprise a readout circuit configured to process the readout signal.

[0016] For example, each sensor pixel may include at least one TFT that controls the readout signal from that sensor. This may include a “sensing TFT” positioned to output the readout signal to a readout line. When each pixel is processed by a scan signal (along the scan line connected to that pixel) and receives a supply voltage (from the supply line connected to that pixel), the sensing TFT may output a readout signal to the readout line to which the sensing TFT is connected. Since a capacitive sensing electrode may be coupled to the gate region of the sensing TFT, the magnitude of the readout signal from the sensing TFT to the readout line may be influenced by the effective capacitance of the capacitive sensing electrode (i.e., the magnitude may indicate the proximity of the conductive material being detected to the capacitive sensing electrode). The sensor may be configured to repeat this process for different sensor pixels so that a readout signal is acquired for each sensor pixel in the array.

[0017] For capacitive biomechanical sensors, the number of sensor pixels per unit area may be relatively high. For example, the sensor may have a spatial resolution between approximately 300 and 500 pixels per inch. In this case, as can be understood, the conductive lines of the sensor array may be arranged very close to each other. In this case, the capacitive coupling between adjacent lines may not be negligible. Therefore, the problems associated with this capacitive coupling may be eliminated by fixing adjacent lines, as disclosed herein.

[0018] In one embodiment, a method is provided for operating a capacitive sensor, the sensor comprising (i) a plurality of read lines and (ii) an array of sensor pixels, each sensor pixel being connected to a read line and comprising a capacitive sensing electrode, the method comprising: obtaining a signal from a first read line indicating the charge at the capacitive sensing electrode of at least one sensor pixel connected to the first read line, and maintaining a second read line at a read reference voltage while obtaining the signal from the first read line.

[0019] In one embodiment, a method is provided for operating a capacitive sensor, the sensor comprising (i) a plurality of supply lines and (ii) an array of a plurality of sensor pixels, each sensor pixel being connected to a supply line and comprising a capacitive sensing electrode, the method comprising: acquiring a signal indicating the charge at the capacitive sensing electrode of at least one sensor pixel connected to a first supply line, and maintaining a second supply line at a supply reference voltage while acquiring the signal from the at least one sensor pixel connected to the first supply line.

[0020] In one embodiment, a method is provided for operating a capacitive sensor, the sensor comprising (i) a plurality of read lines, (ii) a plurality of supply lines, and (iii) an array of a plurality of sensor pixels, each sensor pixel being connected to a read line and a supply line and comprising a capacitive sensing electrode, the method comprising: obtaining a signal from a first read line indicating the charge at the capacitive sensing electrode of at least one sensor pixel connected to the first read line and a first supply line; maintaining a second read line at a read reference voltage while obtaining the signal from the first read line; and maintaining a second supply line at a supply reference voltage while obtaining the signal from the first read line.

[0021] The method may include connecting a first read line to a read circuit and connecting a second read line to a read reference voltage source. The method may also include connecting a first supply line to a pixel supply voltage source and connecting a second supply line to a supply reference voltage source. (i) connecting a second read line to a read reference voltage source and (ii) connecting a second supply line to a supply reference voltage source may include connecting the second read line and the second supply line to the same reference voltage source. The method may also include controlling the application of selection signals to a plurality of selection lines in order to control the connections of the read lines and / or supply lines.

[0022] Aspects of this disclosure may provide one or more computer program products comprising computer program instructions configured to program a capacitive sensor to implement any of the methods disclosed herein. [Brief explanation of the drawing]

[0023] Some examples of this disclosure are described hereby for illustrative purposes only, with reference to the figures.

[0024] [Figure 1a] Figure 1a is a schematic diagram showing a capacitive sensor. [Figure 1b] Figure 1b is a schematic diagram showing the operation of the capacitive sensor in Figure 1a. [Figure 2a] Figure 2a is a schematic diagram showing a capacitive sensor. [Figure 2b] Figure 2b is a schematic diagram showing the operation of the capacitive sensor in Figure 2a. [Figure 3a] Figure 3a is a schematic diagram showing a capacitive sensor. [Figure 3b] Figure 3b is a schematic diagram showing the operation of the capacitive sensor in Figure 3a.

[0025] In drawings, similar reference numbers are used to indicate similar elements. [Modes for carrying out the invention]

[0026] Embodiments of the present disclosure relate to capacitive sensors designed to mitigate the effects of undesirable effects associated with parasitic capacitive coupling of different components within a sensor. The sensors of the present disclosure are formed by an array of multiple sensor pixels, each sensor pixel being connected to a plurality of different electrically conductive lines. For example, each sensor pixel may be connected to a supply line to receive a supply voltage from the same supply line (when operating) and to a read line to output a read voltage to the same read line (when operating). In the sensors of the present disclosure, supply lines and / or read lines that are currently deactivated (i.e., not connected to any operating pixel) may be fixed at a reference voltage. Thus, these fixed reference voltage lines may provide a constant and known parasitic capacitive coupling effect with the active lines. In doing so, further non-quantifiable noise sources may be removed from the read signal from the operating pixels.

[0027] Here, several different examples of capacitive sensors are described with reference to Figures 1a to 3b. For each of these examples, the disclosure primarily relates to a mechanism that connects a non-operating line to a reference voltage and an active line to the relevant circuitry required to obtain measurements from the operating pixel. It will be understood in the context of the disclosure that the specific mechanism for each individual sensor pixel should not be considered limiting. For example, any pixel design may be used, and a scanning signal is used to operate each pixel, and the operating pixel receives a supply voltage and outputs a readout signal from the operating pixel.

[0028] The first example of a capacitive sensor is described with reference to Figures 1a and 1b. Figure 1a shows the sensor configuration, and Figure 1b shows an example of the sensor in operation. The black circles indicate electrical connections.

[0029] Figure 1a shows the sensor 10. The sensor 10 is formed by an array of sensor pixels 100. The sensor 10 also includes a plurality of different conductive lines across the sensor array. The conductive lines include a plurality of supply lines 110, a plurality of read lines 120, and a plurality of scan lines 130.

[0030] Each of the supply lines 110 is ("V s-ref The supply reference voltage (indicated as "V"), or ("V") s-active Each of the active supply voltages (indicated as "V") may be connected to one of the active supply voltages. To illustrate this feature, each supply line 110 is shown with an associated supply line switch 113 (for example, switching between two supply line connections). Each read line 120 is connected to ("V" r-ref It may be connected to either a read reference voltage (indicated as "Read") or the read circuit of sensor 10 (indicated as "Read"). To illustrate this function, each read line 120 is indicated by an associated read line switch 123 (for example, switching between two read line connections).

[0031] Sensor 10 is formed by an array of sensor pixels 100. The array comprises multiple rows of sensor pixels 100 and multiple columns of sensor pixels 100. Figure 1a shows a 4x4 grid, but it will be understood that the array may be substantially larger. Conductive lines conform to the pattern of sensor pixels 100 in the sensor array.

[0032] As shown in Figure 1a, each scan line 130 extends horizontally across the array. Each scan line 130 is associated with a sensor pixel 100 in one row of the array. Each scan line 130 may be connected to all sensor pixels 100 in each row of the scan line 130 of the array. The scan lines 130 run substantially parallel to each other (for example, each scan line 130 may be parallel to the scan line 130 adjacent to each other). Each scan line 130 is connected to a source that provides the scan signal.

[0033] As shown in Figure 1a, each supply line 110 extends vertically across the array. Each supply line 110 is associated with a sensor pixel 100 in one column of the array. Each supply line 110 may be connected to all pixels 100 in each column of the supply line 110 of the array. The supply lines 110 may run substantially parallel to one another (for example, each supply line 110 may be parallel to an adjacent supply line 110). Each supply line 110 is switchably connected to either a supply reference voltage source or a supply active voltage source.

[0034] As shown in Figure 1a, each read line 120 extends vertically across the array. Each read line 120 is associated with a sensor pixel 100 in one column of the array. Each read line 120 may be connected to all pixels 100 in each column of read lines 120 of the array. The read lines 120 may run substantially parallel to each other (for example, each read line 120 may be parallel to any adjacent read line 120). Each read line 120 may run substantially parallel to the supply lines 110 (for example, each read line 120 may be parallel to any adjacent supply lines 110). The read lines 120 and supply lines 110 may run substantially orthogonal to the scan lines 130 (for example, orthogonal). Each read line 120 is switchably connected to either a read reference voltage source or the read circuit of the sensor 10.

[0035] Each sensor pixel 100 is connected to a scan line 130, a supply line 110, and a read line 120. In Figure 1a, each sensor pixel 100 is connected to one of these lines, but each sensor pixel 100 may be connected to more than one. For example, each sensor pixel 100 may be connected to two (or more) scan lines 130. Each row of sensor pixels 100 has a supply line 110 and a read line 120 for that row. Thus, each supply line 110 has a corresponding read line 120 associated with the same sensor pixel 100. Each supply line 110 and the read line 120 corresponding to each supply line 110 are either in an active state where one or more sensor pixels 100 in the row are operational (i.e., providing read signals from one or more of the same sensor pixels 100), or in an inactive state where the sensor pixels 100 in the row are not operational. At least a portion of the supply lines 110 and / or read lines 120 may be located adjacent to conductive lines associated with different rows of sensor pixels 100. For example, as shown in Figure 1a, the read lines 120 from each row are located near and parallel to the supply lines 110 for the next row.

[0036] Each sensor pixel 100 is provided with a capacitive sensing electrode. Each sensor pixel 100 may include one or more TFTs that control the output of a readout signal from the sensor pixel. For example, the capacitive sensing electrode for each pixel 100, the scanning line 130, and the supply line 110 may be connected (directly or indirectly) to the TFT of that sensor pixel. The TFT may also be connected to the readout line 120 for that pixel 100 (for example, a conductive path through the TFT may connect the supply line 110 to the readout line 120). The operation of the scanning line 130 and the amount of charge stored in the capacitive sensing electrode may control the current flowing through the TFT to the readout line 120.

[0037] Sensor 10 is configured to selectively connect each of the supply lines 110 to either a supply reference voltage source or a supply active voltage source. For example, Sensor 10 may include one or more switches (e.g., supply line switches 113) that are operable to select whether each of the supply lines 110 is connected to a supply reference voltage source or a supply active voltage source. Sensor 10 is configured to selectively connect each of the read lines 120 to either a read reference voltage source or the read circuit of Sensor 10. Each of the read lines 120 may be switchably connectable to a processing channel in the read processing circuit of Sensor 10. For example, Sensor 10 may include one or more switches (e.g., read line switches 123) that are operable to select whether each of the read lines 120 is connected to a read reference voltage source or to the read circuit of Sensor 10.

[0038] The sensor 10 is configured to control its operation such that one or more of the rows of sensor pixels 100 are activated (i.e., one or more of the same row contains activated pixels) and one or more of the rows of sensor pixels 100 are deactivated (i.e., one or more of the same row does not contain any activated pixels).

[0039] For an activated row, at least one sensor pixel 100 within that row is activated. To activate a sensor pixel 100 in a row, the sensor 10 is configured to provide an active supply voltage to the pixel 100 by providing a scan signal to a scan line 130 connected to the pixel 100 (for example, by providing a scan signal to the scan line 130 associated with the row of pixels 100 containing the activated pixel 100 in the row) (for example, by providing an active supply voltage to the supply line 110 associated with the row of pixels 100). In this regard, the sensor 10 may be configured to selectively activate the associated scan line 130 and supply line 110. For example, the sensor 10 may be configured to connect the scan line 130 to a voltage source to provide a scan signal to the scan line 130. Similarly, the sensor 10 may be configured to connect the supply line 110 to a supply active voltage source to provide an active supply voltage to the supply line 110 (and thus to the activated sensor pixels in the row of sensor pixels 100). Activating the associated scan line 130 may include applying a signal, such as a voltage signal, to the scan line that sufficiently activates the TFT of the sensor pixel 100 to output a readout signal. For example, in an NMOS mechanism, this may include applying a "high" voltage to the scan line 130 (and therefore to the sensor pixel 100). However, it will be understood that other mechanisms may be used, for example, using PMOS.

[0040] Each operating sensor pixel is configured to output a read signal to a read line 120 connected to that sensor pixel. Sensor 10 is configured such that each operating read line (i.e., the read line 120 connected to the operating pixel) is connected to the read signal processing circuit of sensor 10. Thus, each operating read line connects the operating sensor pixel to the read signal processing circuit of sensor 10. The read signal processing circuit is configured to process the read signals received from the operating pixels.

[0041] In other words, for each row containing an actuating sensor pixel (i.e., for each actuating row), the sensor 10 is configured to connect the associated supply line 110 (supply line 110 for that row) to a supply active voltage source and the associated read line 120 (read line 120 for that row) to the read circuit of the sensor 10. The sensor 10 is configured to select which sensor pixel 100 in the row will be actuated by applying a scan signal to the scan line 130 connected to that sensor pixel.

[0042] For a non-operating row, the sensor pixels 100 in that row are not operated (all sensor pixels 100 in that row are deactivated). Sensor 10 is configured to set at least one of the supply line 110 and the read line 120 for the non-operating row to a reference voltage. Sensor 10 may be configured to (i) set the supply line 110 to a supply line reference voltage and (ii) set the read line 120 to a read reference voltage. To set the supply line 110 to a supply line reference voltage, sensor 10 connects the supply line 110 to a supply reference voltage source (for example, the supply line 110 to a V s-ref The sensor 10 is configured to set the read line 120 to a read reference voltage. To set the read line 120 to a read reference voltage, the sensor 10 connects the read line 120 to a read reference voltage source (for example, setting the read line 120 to V r-ref The system is configured to be set to a reference voltage. Therefore, the supply line 110 and the read line 120 for the same row may be reference voltages, respectively, and the read line 120 is disconnected from the read circuit of the sensor 10. No read signals are obtained from the same row of pixel 100. Because the voltages of the supply line 110 and / or the read line 120 are fixed for this non-operating row, it may be precisely determined how much parasitic capacitive coupling, if any, exists between these lines and any neighboring operating lines.

[0043] In other words, for each column that does not include an active sensor pixel (i.e., for each non-active column), the sensor 10 is configured to connect the associated supply line 110 (the supply line 110 for the same column) to a supply reference voltage source and connect the associated readout line 120 (the readout line 120 for the same column) to a readout reference voltage source. Thus, the supply line 110 is held at V s-ref and the readout line 120 is at V r-ref while any readout signal is being acquired from the active pixels 100 in other columns of the sensor array. Any sensor pixel 100 in a non-active column connected to an active scan line remains non-active because it cannot output any readout signal at all.

[0044] The supply reference voltage (V s-ref ) may be the same as the readout reference voltage (V r-ref ). The supply line 110 and the readout line 120 for the non-active column may be connected to a common reference voltage source. For example, as shown in FIG. 1a, V s-ref and V r-ref may originate from a common voltage source (e.g., V s-ref and V r-ref may be the same voltage source). The reference voltage (for one or both of the supply line 110 and the readout line 120) may be selected based on the voltage of the readout circuit of the sensor 10. For example, the reference voltage may be selected to correspond to this voltage of the readout circuit, and as a result, for example, the reference voltage is the readout circuit voltage or close to the readout circuit voltage. The reference voltage may be within the threshold voltage of the readout circuit voltage. For example, the reference voltage may be within 1 volt of the readout circuit voltage, or for example, within 0.5V or 0.25V.

[0045] By using a reference voltage for the non-operating line that is the read circuit voltage or close to the read circuit voltage, the non-operating line has a voltage similar to that of the operating read line. Therefore, the capacitive coupling effect between the operating read line and the non-operating line adjacent to it is significantly reduced. As can be understood, if the operating read line has a voltage similar to that of the non-operating supply and / or read line adjacent to it, the capacitive coupling between the operating read line and the non-operating supply and / or read line is small (any capacitive coupling is minimal when the voltages are the same). Also, by maintaining the non-operating read line at a voltage that is the read circuit voltage or close to it, this may reduce the need to repeatedly charge / discharge the read line so that it is the read circuit voltage when the read line is operating. This, in turn, may reduce the overall power consumption of the sensor 10.

[0046] For the working pixels, the sensor 10 is configured to acquire a readout signal in the form of a current signal. The readout signal processing circuit may include one or more integrators. The circuit may be configured to acquire a representation (e.g., a digital representation) of the amount of charge stored in the capacitive sensing electrode for each sensor pixel 100 (e.g., a representation of the proximity of the detected conductive material to the same capacitive sensing electrode).

[0047] The reading circuit of sensor 10 may have multiple processing channels, each of which is configured to receive a read signal and obtain a relevant indication from the read signal. The sensor of this disclosure may be configured to multiplex read signals from each of several different read lines 120 into a single processing channel of the reading circuit. In other words, sensor 10 may be configured to selectively connect one of several different read lines 120 to a processing channel of the reading circuit. By doing so, the total number of processing channels required for the reading circuit is reduced (and therefore the cost and complexity required to implement the reading circuit are reduced).

[0048] For example, the sensor 10 may be arranged such that each processing channel of the read circuit may be associated with multiple different read lines 120. The sensor 10 may be configured to selectively connect each of the read lines 120 to the processing channel. The sensor 10 may simply be configured to connect one read line 120 to the processing channel at a time. Each read line 120 may simply be connectable to one processing channel. The sensor 10 may simply be configured to connect an active read line to a processing channel. For example, for each group of read lines 120 associated with one processing channel of the read circuit, the sensor 10 may be configured to sequentially connect each read line 120 to the processing channel (so that each read line 120 operates sequentially). In other words, for each group of read lines 120 associated with a single processing channel of the read circuit, the sensor 10 may simply be configured to activate one of the read lines 120 at any given time and deactivate the remaining read lines 120. For each group of read lines 120, when one read line is activated (as is the supply line 110 associated with that read line), the remaining lines in the group are deactivated.

[0049] Sensor 10 is configured to acquire a readout signal indicating the charge at the capacitive sensing electrode of one or more actuating sensor pixels. In this regard, sensor 10 is configured to apply a supply signal to an (actuating) supply line 110 connected to an actuating sensor pixel, thereby connecting the (actuating) readout line connected to the actuating sensor pixel to a processing channel of the readout circuit. All other readout lines associated with the processing channel are deacted (i.e., connected to a reference voltage) like the supply line 110 associated with the readout line. In other words, sensor 10 is configured to acquire a signal from the first readout line indicating the charge at the capacitive sensing electrode of at least one sensor pixel 100 connected to the first readout line and the first supply line, and at the same time, maintain the second supply line at a supply reference voltage and the second readout line at a readout reference voltage while acquiring the signal from at least one sensor pixel 100 connected to the first supply line and the first readout line.

[0050] Here, one exemplary step of how to operate this sensor 10 shown in Figure 1a is described with reference to Figure 1b.

[0051] Figure 1b shows the same sensor 10 as in Figure 1a. Furthermore, thick black lines are used to indicate which conductive lines and sensor pixels are activated. Here, activated and deactivated lines are shown in Figure 1b. The sensor array shown in Figure 1b has two activated supply lines 111, two deactivated supply lines 112, two activated read lines 121, two deactivated read lines 122, one activated scan line 131, and three deactivated scan lines 132. Also, activated sensor pixels 101 and deactivated sensor pixels 102 are shown in Figure 1b.

[0052] As described above, the sensor 10 may be configured to operate with only a subset of sensor pixels 100 that are active at any given time. That is, the sensor array operates with one or more active sensor pixels 101 and one or more inactive sensor pixels 102 at any given time. The sensor 10 may operate with active sensor pixels 101 in some but not all columns of the sensor array. For each group of read lines 120 associated with the same single processing channel of the read circuit, only one of the columns operates at any given time. Typically, there may be only one row of the sensor array at a time.

[0053] In the example shown in Figure 1b, the sensor 10 is configured such that all of its actuation pixels 101 are in one row, and one pixel 100 is actuated every other column. One actuation scan line 131 exists as shown in Figure 1b. This actuation scan line 131 is connected to all of the sensor pixels 100 in the same row (the second row shown in Figure 1b). Two actuation supply lines 111 exist. Each supply line is connected to all of the sensor pixels 100 in each column of sensor pixels (the first and third columns shown in Figure 1b). Two actuation readout lines 121 exist. The two actuation readout lines 121 correspond to the two actuation supply lines 111. The two actuation readout lines 121 are also connected to all of the sensor pixels in each column of sensor pixels (the first and third columns shown in Figure 1b).

[0054] Each of the active supply lines 111 is connected to a supply active voltage source, and each of the non-active supply lines 112 is connected to a supply reference voltage source. Therefore, the active supply lines 111 (the first and third columns) are V s-active Therefore, the non-operating supply line 112 (the second and fourth columns) is V s-refEach of the active read lines 121 is connected to a read circuit (for example, to the processing channel of each read circuit), and each of the non-active read lines 122 is connected to a read reference voltage source. Thus, the active read lines 121 (the first and third columns) are arranged to provide read signals to the read circuit, and the non-active read lines 122 (the second and fourth columns) are V r-ref The actuated scanning line 131 has a signal that is applied to the actuated scanning line 131 for actuation. For example, in the case of NMOS, this may include driving the actuated scanning line 131 to a higher voltage than that of the non-actuated scanning line 132 (e.g., the scanning voltage). However, it will be understood in the context of this disclosure that any suitable actuation signal (e.g., the scanning voltage) may be applied to the actuated readout line 122. This actuation signal is different from any signal applied to the non-actuated line 132 (the signal may not be applied to the non-actuated line 132).

[0055] The actuation sensor pixel 101 is connected to both the actuation scanning line 131 and the actuation supply line 111. In Figure 1b, these are the sensor pixels in the second row of the first and third columns. The non-actuation sensor pixel 102 does not output a read signal to the read circuit.

[0056] During operation, a scanning signal is applied to the operating scanning line 131. The scanning signal is provided to each sensor pixel 100 in the row associated with the scanning line (since the scanning line is connected to all sensor pixels 100 in that row). Supply voltage V s-active The supply voltage V is provided to the operating supply line 111. s-active The power is supplied to each sensor pixel 100 in the column associated with the operating supply line 111 (since the supply line is connected to all sensor pixels 100 in each column of sensor pixels 100). The operating sensor pixel 101 receives the scan signal and the supply voltage V s-active It receives both the scanning signal and the supply voltage V. s-activeThey either receive only one of the two, or neither.

[0057] For each operating sensor pixel, applying a scanning signal to the sensor pixel 100 may function to switch in one or more TFTs of the sensor pixel. For each operating sensor pixel, the supply voltage V s-active Applying the voltage to the sensor pixel 100 may allow one or more TFTs of the sensor pixel 100 to output an electrical signal (when one or more TFTs are operating). For example, each sensor pixel 100 may be arranged such that the TFT of the sensor pixel 100 is connected to a capacitive sensing electrode to receive a scanning signal. The TFT is connected to the scanning line (and therefore to the supply voltage V s-active A variable conduction path may be provided between the sensor and the readout line, and the amount of current flowing through the readout line indicates the charge stored in the capacitive sensing electrode. Therefore, the scanning signal and the supply voltage V s-active For a sensor pixel 100 that receives both signals, the sensor pixel 100 may output a readout signal indicating the charge stored in its capacitive sensing electrode. The readout line connected to the operating sensor pixel (i.e., the operating readout line 121) is also connected to the readout circuit of the sensor 10. Therefore, the readout signal from the operating sensor pixel is provided to the processing channel of the readout circuit for processing the readout signal.

[0058] This conduction sequence is shown in Figure 1b, where two actuation sensor pixels 101 are connected to both actuation scanning line 131 and actuation supply line 111, and the pixels 101 output a read signal to actuation read line 121 which is connected to a read circuit (these different actuation lines are shown in bold in Figure 1b).

[0059] For the remaining sensor pixels 102, each sensor pixel 102 is connected to a non-operating scanning line 132 and / or a non-operating supply / read line.

[0060] For non-operational sensor pixels 102 that are not connected to the operating scan line 131, the sensor pixels do not operate due to the scan signal, and therefore no read signal is provided from these sensor pixels. For non-operational sensor pixels 102 that are not connected to the operating supply line and the operating read line, the supply line and read line to which the non-operational sensor pixels 102 are connected are fixed at a reference voltage. Therefore, since the supply line and read line connected to each non-operational sensor pixel 102 have the same voltage, a read signal cannot be output.

[0061] Therefore, during operation, any non-operating supply line 112 and read line 122 are reference voltages. These lines may remain fixed and constant reference voltages while read signals are acquired from the operating sensor pixels 101. Any non-operating sensor pixels 102 in the operating array do not need to output read signals to their respective read processing channels because any non-operating sensor pixel 102 is not operated by the scan line (i.e., any non-operating sensor pixel 102 does not receive a scan signal). In other words, only sensor pixels that supply any current / voltage to the conductive lines of the sensor array are operating sensor pixels 101. Therefore, this mechanism may reduce noise associated with parasitic coupling between different conductive lines / sensor pixels in the array.

[0062] Here, another example of a capacitive sensor is described with reference to Figures 2a and 2b.

[0063] Figure 2a shows a sensor 10 similar to that described above in relation to Figures 1a and 1b. The sensor 10 shown in Figure 2a includes further circuitry that provides relevant selective connections with respect to the supply line 110 and the read line 120. Common reference voltage (V COM ) is used for Figure 2a. Compared with Figure 1a, in Figure 2a, the common reference voltage V COM This is the supply reference voltage (V in Figure 1a). s-ref ) and the read reference voltage (V in Figure 1a) r-ref It provides both the supply voltage (VDD ) is used for the operating supply line, and the operating read line is connected to the read circuit. Compared with Figure 1a, in Figure 2a the supply voltage V DD The active supply voltage V s-active To provide.

[0064] Similar to the sensor 10 in Figure 1a, the sensor 10 in Figure 2a includes a plurality of sensor pixels 100, a supply line 110, a read line 120, and a scan line 130. The sensor 10 also includes a non-operating connection circuit 160 and an operating connection circuit 170. The non-operating connection circuit 160 connects the supply line and read line of the non-operating row to a reference voltage (V COM The operating connection circuit 170 is for connecting to the supply line and read line of the operating train, and the supply voltage (V DD This is for connecting to the processing channels of the read circuit.

[0065] The non-operating connection circuit 160 is formed of a plurality of conductive lines and a plurality of associated switches. The conductive lines may include control / signal lines for the sensor array. The conductive lines are connected to associated switches such that the application of an electrical signal along the conductive line selectively opens or closes the switch. The non-operating connection circuit 160 includes a first non-operating selection line 161, a second non-operating selection line 162, and a reference voltage line 165. The non-operating connection circuit 160 also includes a non-operating supply switch 140 for each of the supply lines 110 and a non-operating read switch 150 for each of the read lines 120.

[0066] The actuation connection circuit 170 is formed of a plurality of conductive lines and a plurality of associated switches. The conductive lines are connected to the associated switches such that the application of an electrical signal along the conductive lines selectively opens or closes the switches. The actuation connection circuit 170 includes a first actuation selection line 171, a second actuation selection line 172, and a supply voltage line 175. The actuation connection circuit 170 also includes actuation supply switches 145 for each supply line 110 and actuation read switches 155 for each read line 120. The actuation connection circuit 170 includes a read connection channel 125.

[0067] The mechanism of the sensor pixels 100, scanning lines 130, supply lines 110, and read lines 120 across the sensor array is the same as the mechanism in Figure 1a. That is, each read line 120 has a corresponding supply line 110 connected to the same row of sensor pixels 100.

[0068] Each of the supply lines 110 is connected to both the non-acting connection circuit 160 and the acting connection circuit 170. Each of the supply lines 110 is connected to the reference voltage line 165 via a non-acting supply switch 140. Each of the non-acting supply switches 140 is also connected to one of the non-acting selection lines. As will be described in more detail below, the sensor 10 selectively opens / closes each of the non-acting supply switches 140 by selectively applying an electrical signal to the non-acting selection line to which the non-acting supply switch 140 is connected (therefore, the supply line 110 is V COMThe switches are configured to be selectively set to either state or state. As shown in Figure 2a, each switch may be provided by a transistor, for example, a TFT. The control terminal of each non-operating supply switch 140 (e.g., the gate region of the TFT) is connected to one of the non-operating selection lines. The conductive channel through each non-operating supply switch 140 (e.g., the source-drain channel of the TFT), when opened, electrically connects the reference voltage line 165 to the supply line 110 and all sensor pixels 100 connected to the supply line 110.

[0069] Each of the supply lines 110 is connected to the supply voltage line 175 via an actuation supply switch 145. Each actuation supply switch 145 is also connected to one of the actuation selection lines. Sensor 10 selectively opens / closes each of the actuation supply switches 145 by selectively applying an electrical signal to the actuation selection line to which the actuation supply switch 145 is connected (therefore, the supply line 110 is V DD The system is configured to be selectively set to one of the following: Each control terminal of the actuation supply switch 145 (e.g., the gate region of the TFT) is connected to one of the actuation selection lines. When the conductive channels (e.g., the source-drain channels of the TFT) passing through each actuation supply switch 145 are opened, they electrically connect the supply voltage line 175 to the supply line 110 and all the sensor pixels 100 connected to the supply line 110.

[0070] Each of the read lines 120 is connected to both the non-operating connection circuit 160 and the operating connection circuit 170. Each of the read lines 120 is connected to the reference voltage line 165 via a non-operating read switch 150. Each of the non-operating read switches 150 is also connected to one of the non-operating selection lines. Sensor 10 selectively opens / closes each of the non-operating read switches 150 by selectively applying an electrical signal to the non-operating selection line to which the non-operating read switch 150 is connected (therefore, the read line 120 is V COMThe system is configured to be selectively set to one of the non-operated readout switches 150. Each control terminal of the non-operated readout switch 150 (e.g., the gate region of the TFT) is connected to one of the non-operated selection lines. The conducted channel through each non-operated readout switch 150 (e.g., the source-drain channel of the TFT), when opened, electrically connects the reference voltage line 165 to the readout line 120 and all sensor pixels 100 connected to the readout line 120.

[0071] The read line 120 is connected to the read connection channel 125 via the actuated read switch 155. The read connection channel 125 is connected to the processing channel of the sensor 10's read circuit. Each actuated read switch 155 is also connected to one of the actuated selection lines. The sensor 10 is configured to selectively open / close each actuated read switch 155 (thereby selectively connecting the read line 120 to the read connection channel 125) by selectively applying an electrical signal to the actuated selection line to which the actuated read switch 155 is connected. The control terminal of each actuated read switch 155 (e.g., the gate region of the TFT) is connected to one of the actuated selection lines. When the conductive channel through each actuated read switch 155 (e.g., the source-drain channel of the TFT) is open, it electrically connects the read line 120 and all sensor pixels 100 connected to the read line 120 to the read connection channel 125.

[0072] Sensor 10 is configured to multiplex the read signals from sensor pixels 100 such that each of the multiple read lines 120 may be connectable to the same single read processing channel of the sensor 10's read processing circuit. Sensor 10 is configured to multiplex the connections such that only one read line 120 is connected to each of the single read processing channels of the read processing circuit at any given time. The read lines 120 may be provided in different groups, and each group of read lines 120 is associated with a single processing channel of the read processing circuit. In other words, for each group, each read line 120 in that group may be connected to the same read processing channel. For each group of read lines 120, Sensor 10 is simply configured to connect one read line 120 in that group to the associated read processing channel for that group at any given time. Other read lines 120 in the group are not connected to the same read processing channel at the same time.

[0073] Each group of read lines 120 may include two or more read lines 120 (and two or more supply lines 110 associated with each read line 120). Two read lines per group exist for the examples in Figures 2a and 2b (four read lines per group exist for Figures 3a and 3b, as described below).

[0074] Figure 2a shows two groups, each including two read lines 120 and two supply lines 110 associated with the read lines 120. Each group includes a read connection channel 125 connected to a processing channel of the read processing circuit. Each read line 120 in a group is selectively connectable to the read connection channel 125 for that group. Thus, each group is associated with two columns of sensor pixels 100. Hereinafter, the columns of sensor pixels 100 will be referred to as the "first column" for the left column and the "second column" for the right column. The sensor 10 is configured to operate with one column connected to the reference voltage line 165 and the other column connected to the supply voltage line 175 and the read connection channel 125.

[0075] For each row of sensor pixels 100, the deactivation supply switch 140 and the deactivation readout switch 150 are connected to the same conductive line. Similarly, for each row of sensor pixels 100, the activation supply switch 145 and the activation readout switch 155 are connected to the same conductive line. The first row of sensor pixels 100 has a deactivation switch for that row connected to a second deactivation selection line 162. The first row of sensor pixels 100 has an activation switch for that row connected to a first activation selection line 171. The first deactivation selection line 161 and the first activation selection line 171 may be provided by the same conductive line, or they may be provided by separate conductive lines. If provided by separate conductive lines, the two conductive lines may be connected to a common source (e.g., a common voltage source). The second row of sensor pixels 100 has a deactivation switch for the second row connected to the first deactivation selection line 161. The second row of sensor pixels 100 also has an activation switch for the second row connected to the second activation selection line 172. Here again, the second activation selection line 172 and the second deactivation selection line 162 may be provided by the same line or by separate lines.

[0076] Sensor 10 is configured to control the application of electrical signals to the conductive lines of the non-actuating connection circuit 160 and the acting connection circuit 170 in order to selectively open / close the non-actuating switch and the acting switch. For each group of rows of sensor pixels 100, Sensor 10 controls the supply voltage (V DD The sensor 10 is configured to control operation such that it has one co-row supply line 110 connected to the read connection channel 125 (and thus to the processing channel of the read processing circuit). The other rows in the same group (one row in the example of Figure 2a) are connected to a reference voltage (V COM It is configured to control the operation so that it has other read lines 120 and supply lines 110 in the same row that are connected to it.

[0077] To activate a row of sensor pixels 100, the sensor 10 is configured to apply electrical signals to the deactivation selection line and activation selection line associated with the same row of sensor pixels 100. For the first row, the associated lines are the first deactivation selection line 161 and the first activation selection line 171. By applying electrical signals to the first deactivation selection line 161 and the first activation selection line 171, the first row of sensor pixels 110 is activated and the second row of sensor pixels 110 is deactivated. For the second row, the associated lines are the second deactivation selection line 162 and the second activation selection line 172. By applying electrical signals to the second deactivation selection line 162 and the second activation selection line 172, the second row of sensor pixels 110 is activated and the first row of sensor pixels 110 is deactivated.

[0078] The deactivation switches for the supply line 110 and read for each column are connected to the deactivation selection line associated with the other columns in the group. As shown in Figure 2a, the deactivation supply switch 140 and deactivation read switch 150 for the first column of sensor pixels 100 are connected to the second deactivation selection line 162. Similarly, the deactivation supply switch 140 and deactivation read switch 150 for the second column of sensor pixels 100 are connected to the first deactivation selection line 161. The activation switches for the supply line 110 and read for each column are connected to the activation selection line associated with the same column. As shown in Figure 2a, the activation supply switch 145 and activation read switch 155 for the first column of sensor pixels 100 are connected to the first activation selection line 171. Similarly, the activation supply switch 145 and activation read switch 155 for the second column of sensor pixels 100 are connected to the second activation selection line 172.

[0079] Each of the actuating and deacting switches is configured to close (and thus allow conduction through each of the actuating and deacting switches) in response to an electrical signal being applied to the actuating / deacting selection line to which the switch is connected. Sensor 10 is configured to apply a voltage to the actuating / deacting selection line in order to close the switches connected to the actuating / deacting selection line. Sensor 10 is configured so that an electrical signal (e.g., voltage) is applied at any given time to either (i) the first deacting selection line 161 and the first actuating selection line 171, or (ii) the second deacting selection line 162 and the second actuating selection line 172.

[0080] The deactivation connection circuit 160 and activation connection circuit 170 of the sensor 10 are arranged such that the application of an electrical signal to both the first deactivation selection line 161 and the first activation selection line 171 activates the first column of sensor pixels 100 in each group. This also deactivates the remaining column in the group (i.e., the second column in Figure 2a). Similarly, the application of an electrical signal to the second activation selection line and the second deactivation selection line activates the second column of sensor pixels 100 and deactivates the first column.

[0081] For example, by applying an electrical signal to the first deactivation selection line 161, for example, by driving the first deactivation selection line 161 to a high voltage (without driving the second deactivation selection line 162), this closes the deactivation supply switch 140 and deactivation read switch 150 for the second column of sensor pixels 100, while keeping the corresponding switch for the first column of sensor pixels 100 open. In this way, the supply line 110 and read line 120 for the second column are connected to the reference voltage line 165 (and therefore the reference voltage V COM (This is maintained). The corresponding switch for the first column is open, so the supply line 110 and read line 120 for the first column are not connected to the reference voltage line 165.

[0082] By applying an electrical signal to the first actuation selection line 171, for example, by driving the first actuation selection line 171 to a high voltage (without driving the second deactuation selection line 162), this closes the actuation supply switch 145 and actuation readout switch 155 for the first row of sensor pixels 100, while keeping the corresponding switch for the second row of sensor pixels 100 open. In this way, the supply line 110 for the first row is connected to the supply voltage line 175 (and therefore the supply voltage V DDOnce charged to the specified level, the read line 120 for the first row is connected to the read connection channel 125 (and therefore to the processing channel of the sensor 10's read processing circuit). The corresponding switch for the second row is open, so the supply line 110 and the read line 120 for the second row are not connected to the supply voltage line 175 and the read connection channel 125, respectively.

[0083] The opposite occurs when applying an electrical signal to the second deactivating select line and the second operating select line, for example, by driving these lines to a high voltage (without driving the first deactivating select line and the first operating select line).

[0084] Similar to the examples in Figures 1a and 1b, the sensor 10 is configured to apply a scanning signal to the scanning line 130 of the array in order to activate the sensor pixels 100 in the row (where the activated sensor pixels 100 in the row are also present in the activated column). The activated sensor pixels 100 are activated by the scanning signal and receive the supplied voltage (V DD The read signal from the operating sensor pixel 100 is received and provided to the read connection channel 125, which in turn is provided to the read processing channel of the sensor 10's processing circuit.

[0085] Here, the exemplary operation of sensor 10 in Figure 2a is described with reference to Figure 2b. Thick black lines are used to indicate which of the sensor pixels 100 is activated and which of the selection lines an electrical signal is applied to (for example, which of the selection lines is driven to a high voltage). For each switch, the accompanying "O" or "C" is shown to indicate whether the switch is open (non-conductive) or closed (conductive). Arrows are also used to indicate the direction of the current passing through sensor 10.

[0086] Figure 2b shows the sensor 10 of Figure 2a, which has two working sensor pixels 101. The remaining sensor pixels are non-working sensor pixels 102. The working scan line 131 is in the second row of sensor pixels, and the remaining scan line is the non-working scan line 132.

[0087] As shown, electrical signals are applied to the first deactivation selection line 161 and the first activation selection line 171 (but not to the second deactivation selection line 162 and the second activation selection line 172). In this regard, each of the first lines may be driven up to a high voltage (while the second line is at a low voltage, e.g., zero or a negative voltage). Two first lines are shown as "SW1" because the two identical first lines close the first series of switches (activating the first column), and two second lines are shown as "SW2" because the two identical second lines close the second series of switches (activating the second column).

[0088] When an electrical signal is applied to the first deactivation selection line 161 (for example, when the first deactivation selection line 161 is driven to a high voltage), the second and fourth rows of sensor pixels have a closed deactivation supply switch 141 and a closed deactivation readout switch 151. Thus, these closed switches are electrically conductive and connect their respective supply / readout lines to the reference voltage line 165. Thus, the line is connected to the reference voltage V COM These are held in place. These are shown as the non-operating supply line 112 and the non-operating read line 122. Conversely, the first and third rows of sensor pixels have an open non-operating supply switch 142 and an open non-operating read switch 152. Since these switches are not electrically conductive, their respective supply / read lines are not connected to a reference voltage.

[0089] When an electrical signal is applied to the first operating selection line 171 (for example, by driving line 171 to a high voltage), the first and third rows of sensor pixels have a closed operating supply switch 146 and a closed operating readout switch 156. Therefore, these closed switches are electrically conductive. The closed operating supply switch connects each of its supply lines to the supply voltage line 175. Therefore, the line receives the supply voltage V DD These are held in place. These are shown as the operating supply lines 111. The closed operating read switches connect each of their read lines to the read connection channel 125 (and thus to the processing channel of the read processing circuit). These are shown as the operating read lines 121. Conversely, the second and fourth rows of sensor pixels have an open operating supply switch 147 and an open non-operating read switch 157. Since these switches are not electrically conductive, each of their supply / read lines is not connected to the supply voltage / read circuit.

[0090] Therefore, the sensor pixels 101 in the second row and the first and third columns are activated. The remaining sensor pixels 102 are deactivated. Current may flow from the supply voltage line 175 to the sensor pixels in the first and third columns. The activated sensor pixels 101 in the columns (those in the second row) then output a read signal to the respective read line of the activated sensor pixel 101, and the read signal is provided to the respective read processing channel of the read circuit. Thus, capacitive measurements may be obtained for the activated sensor pixels 101.

[0091] The non-operating supply line 112 and the non-operating read line 122 are connected by a reference voltage V COM It is held at the reference voltage V. COM The reference voltage V may be selected to be the same as (or close to, for example, within the threshold range of, the same voltage) the voltage of the sensor 10's read processing circuit. Therefore, the operating read line 121 is set to the reference voltage V COMThe same voltage (or reference voltage V) COM The voltage may be similar to that of the other voltage. Therefore, minimal capacitive coupling may exist between each of the actuated read lines 121 and any non-actuated line close to each actuated read line 121 (for example, between each actuated read line 121 and a non-actuated supply line 112 adjacent to each actuated read line 121). This, in turn, may reduce the amount of noise present in the read signal from the actuated sensor pixel 101.

[0092] In the example shown in Figure 2b, sensor 10 operates to acquire readout signals from sensor pixels in the first and third columns of the second row. It will be understood that all different sensor pixels in the array may be activated by changing the scan line to which the scan signal is applied, and / or by applying an electrical signal (e.g., driving a high voltage) to the second actuated / deactivated select line (instead of the first line). For example, by driving the second actuated / deactivated select line to a high voltage, the sensor pixel becomes an actuated sensor pixel in the second and fourth columns, and by changing the actuated scan line 131, the sensor pixel becomes an actuated pixel in a different row.

[0093] Here, another example of a capacitive sensor is described with reference to Figures 3a and 3b.

[0094] Figure 3a shows the capacitive sensor 10. The sensor 10 in Figure 3a is the same as that in Figure 2a, except that each processing channel of the read processing circuit is associated with a group of four read lines (associated supply lines) instead of two as shown in Figure 2a. Therefore, a portion of the sensor array shown in Figure 3a contains only one of the same group of read / supply lines.

[0095] Similar to Figure 2a, the sensor 10 in Figure 3a includes a non-operating connection circuit 160 and an operating connection circuit 170. The non-operating connection circuit 160 connects the supply line and read line of the non-operating row with a reference voltage (V COMThe operating connection circuit 170 is for connecting to the supply line and read line of the operating train, and the supply voltage (V DD ) and the processing channels of the readout processing circuit are connected to each of them. The non-operating connection circuit 160 and the operating connection circuit 170 are each formed of a plurality of conductive lines and a plurality of associated switches, and the circuits are arranged so that the application of an electrical signal to each different conductive line closes each different switch.

[0096] In Figure 3a, the sensor 10 is positioned such that while each row of sensor pixels 100 in the group is activated, the other (three) rows in the group are deactivated. In other words, the sensor 10 supplies a supply voltage (V) to the supply line for one row in the group. DD ) is connected, and at the same time, the remaining columns in the group are connected to the reference voltage (V COM The sensor 10 is configured to have supply lines for the remaining same row connected to the reference voltage (V). Similarly, the sensor 10 connects the read line for one same row in the group to the read connection channel 125, and at the same time, the remaining rows in the group are connected to the reference voltage (V). COM It is configured to have the remaining same-row read lines connected to ).

[0097] The non-actuated connection circuit 160 includes a plurality of conductive lines and a plurality of associated switches. The non-actuated circuit includes a first non-actuated selection line 161, a second non-actuated selection line 162, a third non-actuated selection line 163, a fourth non-actuated selection line 164, and (reference voltage V COMThe system includes a reference voltage line 165 (for connection to the supply line 110). Each supply line 110 has an associated non-operated supply switch assembly 1400, which is formed of a plurality of non-operated supply switches 140a, 140b, 140c. The number of non-operated supply switches corresponds to the number of columns per group (one less than the same number). In the example in Figure 3a, there are three non-operated supply switches in each non-operated supply switch assembly 1400. Each read line 120 has an associated non-operated read switch assembly 1500, which is formed of a plurality of non-operated read switches 150a, 150b, 150c. The number of non-operated read switches corresponds to the number of columns per group (one less than the same number). In the example in Figure 3a, there are three non-operated read switches in each non-operated read switch assembly 1500.

[0098] The actuation connection circuit 170 is formed by a plurality of conductive lines and a plurality of associated switches. The actuation connection circuit 170 includes a first actuation selection line 171, a second actuation selection line 172, a third actuation selection line 173, a fourth actuation selection line 174, and a supply voltage line 175. The actuation connection circuit 170 also includes an actuation supply switch 145 for each supply line 110 and an actuation read switch 155 for each read line 120. The actuation connection circuit 170 includes a read connection channel 125.

[0099] Similar to Figure 2a, each column of sensor pixels 100 has an associated deactivation selection line and an associated activation selection line. The first column (and therefore the first supply line and the first read line) is associated with the first deactivation selection line 161 and the first activation selection line 171. The second, third, and fourth columns are associated with the second selection line, the third selection line, and the fourth selection line, respectively. Similar to Figure 2a, by applying an electrical signal to the first deactivation selection line 161 and the first activation selection line 171, the first column of sensor pixels 110 is activated and the second, third, and fourth columns of sensor pixels 110 are deactivated. By applying an electrical signal to the second deactivation selection line 162, the third deactivation selection line 163, or the fourth deactivation selection line 164, the corresponding column of sensor pixels 100 is activated and the first column of sensor pixels 100 is deactivated. This association will be explained in more detail below.

[0100] Regarding the non-operating connection circuit 160, each supply line 110 is connected to a plurality of non-operating supply switches. Each non-operating supply switch is arranged to selectively connect its respective supply line 110 to a reference voltage line 165. Each non-operating supply switch is connected to its respective non-operating select line. Each non-operating supply switch is arranged to conduct selectively in response to the application of an electrical signal to the non-operating select line to which the switch is connected. For example, each non-operating supply switch may be provided by a transistor, such as a TFT, the gate region of which is connected to the non-operating select line, and the conduction path through which the transistor connects the reference voltage line 165 to the supply line 110.

[0101] As described above, each supply line 110 in the group is connected to a plurality of inactive supply switches. For each supply line 110, each inactive supply switch is connected to a different inactive selection line. Each supply line 110 is connected to an inactive supply switch that is connected to each inactive selection line for the group, except for the inactive selection line associated with that supply line 110. In other words, the supply line 110 for the first column in the group is connected to the inactive supply switches that are connected to the second, third, and fourth inactive selection lines, respectively (but not to the first inactive selection line 161).

[0102] Sensor 10 is positioned such that the application of an electrical signal to a selected non-operating selection line (associated with a selected supply line) electrically conducts through a non-operating supply switch connected to the other supply lines in the group. Each supply line in the group, excluding the selected supply line, is connected to the selected non-operating selection line (and therefore electrically conducts) by the non-operating supply switch associated with the selected supply line. The non-operating supply switch connected to the selected supply line is open (it does not conduct because it is not connected to the selected non-operating selection line). In other words, the application of an electrical signal to one of the non-operating selection lines connects all the supply lines in the group to the reference voltage line 165, except for the supply line associated with that non-operating selection line. The supply line associated with that non-operating selection line is not connected to the reference voltage line 165.

[0103] A similar mechanism is provided for each of the read lines 120 and the non-operating connection circuit 160. That is, each of the read lines 120 is connected to a plurality of non-operating read switches. Each non-operating read switch is arranged to selectively connect its respective read line 120 to a reference voltage line 165. Each non-operating read switch is connected to its respective non-operating select line. Each non-operating read switch is arranged to conduct selectively in response to the application of an electrical signal to the non-operating select line to which the switch is connected. For example, each non-operating read switch may be provided by a transistor, such as a TFT, the gate region of which is connected to the non-operating select line, and the conduction path through which the transistor connects the reference voltage line 165 to the read line 120.

[0104] As described above, each read line 120 in the group is connected to a number of inactive read switches. For each read line 120, each inactive read switch is connected to a different inactive selection line. Each read line 120 is connected to an inactive read switch that is connected to each inactive selection line for the group, except for the inactive selection line associated with that read line 120. In other words, the read line 120 for the first column in the group is connected to the inactive read switches that are connected to the second, third, and fourth inactive selection lines (but not to the first inactive selection line 161).

[0105] Sensor 10 is positioned such that the application of an electrical signal to a selected non-operating selection line (associated with a selected read line) electrically conducts to a non-operating read switch connected to the other read lines in the group. Each read line in the group, excluding the selected read line, is connected to the selected non-operating selection line (and therefore electrically conducts) by the non-operating read switch associated with the selected read line. The non-operating read switch connected to the selected read line is open (it does not conduct because it is not connected to the selected non-operating selection line). In other words, the application of an electrical signal to one of the non-operating selection lines connects all the read lines in the group to the reference voltage line 165, except for the read line associated with that non-operating selection line. The read line associated with that non-operating selection line is not connected to the reference voltage line 165.

[0106] For example, as shown in Figure 3a, the non-operating supply switch assembly for the first supply line is formed by non-operating supply switches 140a, 140b, and 140c. Non-operating supply switch 140a is connected to the second non-operating selection line 162, non-operating supply switch 140b is connected to the third non-operating selection line, and non-operating supply switch 140c is connected to the fourth non-operating selection line. The application of an electrical signal to the second, third, or fourth non-operating selection line electrically conducts the non-operating supply switches 140a, 140b, and 140c respectively, thereby connecting the first supply line to the reference voltage line 165 (and thus the first supply line to V COM (Charge until) Applying an electrical signal to the first non-operating selection line 161 does not cause any of the non-operating supply switches 140a, 140b, and 140c to close, and therefore does not connect the first supply line to the reference voltage line 165.

[0107] Similarly, as shown in Figure 3a, the deactivation read switch assembly for the first read line is formed by deactivation read switches 150a, 150b, and 150c. Deactivation read switch 150a is connected to the second deactivation selection line 162, deactivation read switch 150b is connected to the third deactivation selection line, and deactivation read switch 150c is connected to the fourth deactivation selection line. The application of an electrical signal to the second, third, or fourth deactivation selection line electrically conducts the deactivation read switches 150a, 150b, and 150c respectively, thereby connecting the first read line to the reference voltage line 165 (and thus the first read line to V COM (Charge until it reaches [value]). Applying an electrical signal to the first non-operating selection line 161 prevents any of the non-operating readout switches 150a, 150b, and 150c from closing, and therefore prevents the first readout line from being connected to the reference voltage line 165.

[0108] In the actuation connection circuit 170, each supply line is connected to an actuation supply switch. Each actuation supply switch is arranged to selectively connect its respective supply line to the supply voltage line 175. Each actuation supply switch is connected to an actuation selection line associated with the supply line to which the actuation supply switch is connected. Each actuation supply switch is arranged to conduct selectively in response to the application of an electrical signal to the actuation selection line to which the switch is connected. For example, each actuation supply switch may be provided by a transistor, such as a TFT, the gate region of which is connected to the actuation selection line, and the conduction path through which the transistor connects the supply voltage line 175 to the supply line.

[0109] In other words, the sensor 10 is positioned such that the application of an electrical signal to the selection actuation selection line (associated with the selection supply line) electrically conducts to the actuation supply switch connected to the selection supply line. The selection supply line is connected to the electrically conducting actuation supply switch and therefore to the supply voltage line 175. The other supply lines in the group are not connected to the supply voltage line 175, as each of the other supply lines is connected to an actuation supply switch that is not connected to the selection actuation selection line.

[0110] Each read line is connected to an activated read switch. Each activated read switch is configured to selectively connect its respective read line to a read connection channel 125. Each read line in a group is selectively connectable to the read connection channel 125. Each activated read switch is connected to an activated selection line associated with the read line to which the activated read switch is connected. Each activated read switch is configured to conduct selectively in response to the application of an electrical signal to the activated selection line to which the switch is connected. For example, each activated read switch may be provided by a transistor, such as a TFT, the gate region of which is connected to the activated selection line, and the conduction path through which the transistor connects the supply line to the read connection channel 125.

[0111] In other words, the sensor 10 is positioned such that the application of an electrical signal to the selection-operated selection line (associated with the selection-read line) electrically conducts to the operation-read switch connected to the selection-read line. The selection-read line is connected to the electrically conducting operation-read switch and therefore to the read-connection channel 125. Other read lines in the group are not connected to the read-connection because each of the other read lines is connected to an operation-read switch that is not connected to the selection-operated selection line.

[0112] Sensor 10 is configured to control operation such that, at any given time, one row of sensor pixels 100 in a group is activated and the remaining rows in the group are deactivated. The supply line for the activated row in the group is connected to the supply voltage line 175, and the read line for the activated row in the group is connected to the read connection channel 125. For each of the deactivated rows in the group, the supply line for that deactivated row is connected to the reference voltage line 165, and the read line for that deactivated row is connected to the reference voltage line 165.

[0113] The non-operating connection circuit 160 is configured to selectively connect all but one of the rows in the group to the reference voltage line 165. Thus, the supply line and the read line for the same row in the group are connected to the reference voltage V COM The operating connection circuit 170 is configured to selectively connect one column in a group (not connected to the reference voltage line 165) in order to acquire a read signal. In this regard, the supply line for that column is connected to the supply voltage line 175, and the read line for that column is connected to the read connection channel 125.

[0114] Sensor 10 is configured to selectively apply electrical signals to different activation and deactivation lines in order to select which of the sensor pixels 100 in the array to activate. Sensor 10 is configured such that applying electrical signals to one activation line and its corresponding deactivation line activates the column associated with the two such activation lines, deactivating all other columns in the group. In other words, applying selection signals to the first activation line 171 and the first deactivation line 161 activates the first column of the sensor pixel 100, deactivating the other columns in the group.

[0115] Here, the exemplary operation of sensor 10 in Figure 3a is described with reference to Figure 3b.

[0116] Figure 3b shows the sensor 10 of Figure 3a where a selection signal is applied to both the first deactivation selection line 161 and the first activation selection line 171 (for example, the selection lines are driven to high voltage, as shown by the thick lines in Figure 3b). As a result, all the deactivation switches in the first column are open. These are shown as an open supply switch assembly 1401 and an open readout switch assembly 1501. For each of the other columns, each switch assembly has one closed switch, which is the switch connected to the first deactivation selection line 161. These are shown as a closed supply switch assembly 1402 and a closed readout switch assembly 1502. For the activation connection circuit 170, the activation switches in the first column are closed (shown as a closed activation supply switch 146 and a closed activation readout switch 156), and the activation switches in the other columns are open (shown as an open activation supply switch 147 and an open activation readout switch 157).

[0117] In Figure 3b, the scanning signal is applied to the first scanning line, which is shown as the working scanning line 131 (the other scanning lines shown are the non-working scanning lines 132). Electrical signals are applied to the first non-working select line 161 and the first working select line 171 (for example, the lines are driven up to high voltage), so the supply line for the first column is connected to the supply voltage line 175, and the read line for the first column is connected to the read connection channel 125. Each of the other columns has its own supply line and read line for the other columns connected to the reference voltage line 165. Thus, the supply line for the first column in the group is connected to the supply voltage V DD Once charged, the supply lines for other columns in the group are V, just like the read lines for other columns in the group. COM It is charged to this extent. As shown in Figure 3b, the first row has an operating supply line 111 and an operating read line 121, and the other row has a non-operating supply line 112 and a non-operating read line 122.

[0118] The examples described herein should not be considered limiting, and it will be understood in the context of this disclosure that the underlying technology may be implemented in numerous alternative ways. For example, different switching mechanisms than those shown in the figures may be provided. For example, the switching mechanism described utilizes a thin-film transistor that becomes electrically conductive by applying a positive voltage (above the switch-on voltage for the transistor) to the gate region of the TFT. However, this switching function may be implemented in other ways, such as using different types of transistors to which different signals are applied to open / close the switch. For example, in such a case, the application of a selection signal to a selection line does not have to involve driving that line to a higher voltage (than other selection lines). Similarly, the sensor array is described as having scanning lines extending into rows, supply lines and read lines extending into columns, and provided by multiple rows of sensor pixels and multiple columns of sensor pixels. However, other spatial mechanisms may be provided for sensor pixels and conductive lines. For example, each supply / read line does not have to be associated with every sensor pixel in a column. Alternatively, each of these lines may be associated with multiple different sensor pixels distributed across the sensor array. Each sensor pixel may be connected to one supply line, a read line, and a scan line, but the mechanism relating to the sensor pixel and the conductive line should not be considered limiting.

[0119] In the examples described herein, the sensor is a capacitive sensor, such as a capacitive touch sensor. However, the disclosure may also be implemented with other forms of sensors. For example, instead of each sensor pixel having a capacitive sensing electrode, each sensor pixel may instead have another sensor element configured to provide sensing of a relevant parameter. For example, each sensor pixel may have an optical sensor element configured to provide optical sensing (e.g., X-rays, gamma rays, visible light, etc.). The sensor may also be provided by an active matrix sensor array and may still benefit from fixing a non-active supply / read line to a reference voltage. Similarly, several exemplary sensor pixel designs are described herein, but these should not be considered limiting. Each sensor pixel may be configured to output a readout signal to a readout line indicating the charge at the capacitive sensing electrode of each sensor pixel in response to the application of a scanning signal to a scanning line connected to the sensor pixel and the application of a supply voltage to a supply line connected to the sensor pixel. Any suitable pixel design may be provided for this function. For example, each sensor pixel may have one or more TFTs, and the TFTs of the sensor pixel are arranged to output a readout signal indicating the charge stored in the capacitive sensing electrode. For example, the TFT may output a current to the readout line, which is proportional to the charge in the capacitive sensing electrode, and which is output only when the sensor pixel receives a scanning signal and a supply voltage. For example, a conduction channel through the TFT may provide a selective variable connection between the supply line and the readout line, which is influenced by the capacitive sensing electrode (where the scanning signal functions to conduct through the TFT).

[0120] From the above description, it will be understood that the examples shown in the figures are merely illustrative and include features that may be generalized, omitted, or replaced as described herein and in the claims. Referring to the drawings as a whole, it will be understood that schematic functional block diagrams are used to illustrate the functions of the systems and apparatus described herein. In addition, processing functions may also be provided by devices supported by electronic devices. However, it will be understood that functions do not need to be divided in this way and should not be interpreted as suggesting any specific hardware structure other than those described and claimed below. One or more functions of the elements shown in the drawings may be further subdivided and / or distributed throughout the apparatus of this disclosure. In some examples, the functions of one or more elements shown in the figures may be integrated into a single functional unit.

[0121] As will be understood by those skilled in the art in the context of this disclosure, each of the examples described herein may be implemented in a variety of different ways. Any feature of any aspect of this disclosure may be combined with any of the other aspects of this disclosure. For example, a method aspect may be combined with an apparatus aspect, and a feature described in reference to the operation of a particular element of an apparatus may be provided in a way that does not use that particular type of apparatus. In addition, unless it is expressly stated that some other feature is essential for the operation of that feature, each feature relating to each example is intended to be separable from the feature that each of those features is described in combination with. Each of those separable features may, of course, be combined with any of the other features of the example in which each of those separable features is described, or with any of the other features or combinations of features relating to any of the other examples described herein. Furthermore, equivalents and modifications not described above may be adopted without departing from the invention.

[0122] Certain features of the methods described herein may be implemented in hardware, and one or more functions of the apparatus may be implemented in method steps. Furthermore, it will be understood in the context of this disclosure that the methods described herein do not necessarily have to be performed in the order in which they are described, nor do they necessarily have to be performed in the order in which they are depicted in the drawings. Thus, aspects of this disclosure described with reference to a product or apparatus are also intended to be implemented as methods, and vice versa. The methods described herein may be implemented as computer programs or hardware, or any combination thereof. Computer programs include software, middleware, firmware, and any combination thereof. The programs may be provided as signals or network messages, or recorded on computer-readable media such as tangible computer-readable media capable of storing computer programs in a non-temporary form. Hardware includes computers, handheld devices, programmable processors, general-purpose processors, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), and arrays of logic gates.

[0123] Other examples and modifications of this disclosure will be obvious to those skilled in the art in the context of this disclosure.

Claims

1. A capacitive sensor, Multiple read lines, An array of multiple sensor pixels, It has, Each sensor pixel is connected to a readout line, Capacitive sensing electrode, Equipped with, The aforementioned sensor is From the first readout line, a signal indicating the charge at the capacitive sensing electrode of at least one sensor pixel connected to the first readout line is acquired, While acquiring the signal from the first read line, the second read line is maintained at the read reference voltage. It is configured in such a way. A capacitive sensor characterized by the following features.

2. A capacitive sensor, Multiple supply lines, An array of multiple sensor pixels, It has, Each sensor pixel is connected to a supply line, Capacitive sensing electrode, Equipped with, The aforementioned sensor is A signal indicating the charge at the capacitive sensing electrode of at least one sensor pixel connected to the first supply line is acquired, While acquiring the signal from at least one of the sensor pixels connected to the first supply line, the second supply line is maintained at the supply reference voltage. It is configured in such a way. A capacitive sensor characterized by the following features.

3. Multiple supply lines, It has, Each sensor pixel is connected to a supply line, At least one of the sensor pixels connected to the first read line is connected to the first supply line, The sensor is configured to maintain the second supply line at a supply reference voltage while acquiring the signal from the first read line. The sensor according to claim 1.

4. The supply reference voltage is the same as the read reference voltage. The sensor according to claim 3.

5. Each of the reading lines is, A corresponding supply line connected to the same sensor pixel as the aforementioned readout line, Equipped with, The sensor according to claim 3 or 4.

6. The first read line and the second read line are switchably connected to a single channel of the sensor's read circuit, Optionally, three or more read lines are switchably connected to a single channel of the sensor's read circuit. The sensor according to claim 1 or the sensor according to any claim dependent on claim 1.

7. The sensor is configured to multiplex signals from two or more read lines into the single channel. The sensor according to claim 6.

8. The sensor is configured to selectively connect each read line to either (i) a read reference voltage source that maintains the read line at the read reference voltage, or (ii) a read circuit of the sensor that processes the signals received from the read line. The sensor according to claim 1 or the sensor according to any claim dependent on claim 1.

9. The sensor is configured to selectively connect each supply line to either (i) a supply reference voltage source that maintains the supply line at the supply reference voltage, or (ii) a pixel supply voltage source that provides electrical energy to the sensor pixels connected to the supply line. A sensor according to claim 2 or 3, or a sensor according to any claim dependent on claim 2 or 3.

10. Multiple selection lines, It has, Each selected line is associated with a read line and a corresponding supply line. The sensor is configured to control the application of a selection signal to each of the selection lines in order to control the connection between the read line and the supply line associated with the selection line. The sensor according to claim 3 or the sensor according to any claim dependent on claim 3.

11. The application of a selection signal to a selection line associated with the first read line and the first supply line is performed by (i) connecting the first read line to the read circuit, and (ii) connecting the first supply line to the pixel supply voltage source. The sensor according to claim 10, which is dependent on claims 8 and 9.

12. The application of a selection signal to a selection line associated with the second read line and the second supply line is performed by (i) connecting the second read line to the read reference voltage source, and (ii) connecting the second supply line to the supply reference voltage source. The sensor according to claim 10 or 11, which is dependent on claims 8 and 9.

13. The first read line is adjacent to the second read line, The sensor according to claim 1 or the sensor according to any claim dependent on claim 1.

14. The first supply line is adjacent to the second supply line, A sensor according to claim 2 or 3, or a sensor according to any claim dependent on claim 2 or 3.

15. The aforementioned read reference voltage is selected to correspond to the voltage of the sensor's read circuit. Optionally, the read reference voltage is the same as the voltage of the read circuit, or close to the voltage of the read circuit. The sensor according to claim 1 or the sensor according to any claim dependent on claim 1.

16. The read reference voltage for the second line is the same as the voltage for the first read line. The sensor according to claim 1 or the sensor according to any claim dependent on claim 1.

17. The aforementioned sensor array is Multiple scanning lines, Equipped with, Each sensor pixel is connected to a scan line that receives a scan signal. The sensor according to any one of claims 1 to 16.

18. A method for operating a capacitive sensor, The aforementioned sensor is (i) Multiple read lines, (ii) An array of multiple sensor pixels, Equipped with, Each sensor pixel is connected to a readout line, Capacitive sensing electrode, Equipped with, The aforementioned method, To obtain a signal from the first readout line indicating the charge at the capacitive sensing electrode of at least one sensor pixel connected to the first readout line, While acquiring the signal from the first read line, the second read line is maintained at the read reference voltage, including, A method characterized by the following:

19. A method for operating a capacitive sensor, The aforementioned sensor is (i) Multiple supply lines, (ii) An array of multiple sensor pixels, Equipped with, Each sensor pixel is connected to a supply line, Capacitive sensing electrode, Equipped with, The aforementioned method, To acquire a signal indicating the charge at the capacitive sensing electrode of at least one sensor pixel connected to the first supply line, Maintaining the second supply line at a supply reference voltage while acquiring the signal from at least one of the sensor pixels connected to the first supply line, including, A method characterized by the following:

20. A method for operating a capacitive sensor, The aforementioned sensor is (i) Multiple read lines, (ii) Multiple supply lines, (iii) An array of multiple sensor pixels, Equipped with, Each sensor pixel is connected to a read line and a supply line. Capacitive sensing electrode, Equipped with, The aforementioned method, To obtain a signal from the first read line indicating the charge at the capacitive sensing electrode of at least one sensor pixel connected to the first read line and the first supply line, While acquiring the signal from the first read line, the second read line is maintained at the read reference voltage, While acquiring the signal from the first read line, the second supply line is maintained at the supply reference voltage, including, A method characterized by the following:

21. Connecting the first read line to the read circuit, Connecting the second read line to the read reference voltage source, including, The method according to claim 18 or 20.

22. Connecting the first supply line to a pixel supply voltage source and the second supply line to a supply reference voltage source, including, The sensor according to claim 19 or 20, or the method according to any claim dependent on claim 19 or 20.

23. (i) Connecting the second read line to the read reference voltage source, and (ii) connecting the second supply line to the supply reference voltage source, The second read line and the second supply line are connected to the same reference voltage source. including, The method according to claim 22, which is dependent on claims 20 and 21.

24. Controlling the connection of the read line and / or the supply line by controlling the application of selection signals to a plurality of selection lines, including, The method according to claim 20 or the method according to any claim dependent on claim 20.

25. Computer program instructions configured to program a capacitive sensor to implement the method according to any one of claims 18 to 24, Having, A computer program product characterized by the following features.

Images