Fingerprint detection equipment and methods

Abstract

A fingerprint detection device and method thereof are disclosed. The fingerprint detection device includes: a touch panel; at least one amplifier, including: a first integrator and a second integrator, the first integrator amplifying an electrical signal received from the touch panel into a signal of a first polarity, and the second integrator amplifying the electrical signal into a second signal of a second polarity; and a processor configured to control the amplifier to perform a first integration process and a second integration process on a plurality of electrical signals received from a plurality of nodes of the touch panel.

Description

[0001] Cross-references to related applications

[0002] This application is based on and claims priority to Korean Patent Application No. 10-2020-0016626, filed on February 11, 2020, with the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] This invention relates to a fingerprint detection device and method, and more specifically, to a fingerprint detection device and method including a multi-integrator. Background Technology

[0004] Fingerprint sensors are mainly classified according to their type into optical fingerprint sensors, semiconductor capacitive sensors, semiconductor temperature sensors, semiconductor pressure sensors, ultrasonic sensors, and radio frequency (RF) sensors.

[0005] When using a semiconductor capacitive sensor, the user's finger touches a "panel" that integrates thousands of semiconductor electronic devices and forms a capacitor on the other side. Because the surface of a fingerprint is uneven, with ridges corresponding to raised areas and valleys corresponding to recessed areas, the actual distances between the raised and recessed areas and the panel are different, resulting in different capacitance values. The different capacitance values ​​collected are combined to complete the fingerprint acquisition.

[0006] Furthermore, semiconductor capacitive fingerprint sensors typically include an integrator where the fundamental capacitance of the fingerprint capacitor and the capacitance from the metal layer closest to the fingerprint to ground (i.e., parasitic capacitance) are combined into a large fundamental signal, which is then output. This fundamental signal has an amplitude much larger than the effective signal corresponding to the fingerprint capacitance. This fundamental signal has the problem of easily saturating the integrator and reducing the dynamic range of the fingerprint sensor's output. Summary of the Invention

[0007] One or more embodiments of this disclosure provide a fingerprint detection device and method thereof capable of using a multi-integrator to increase the output dynamic range.

[0008] One or more embodiments of this disclosure provide a fingerprint detection device and method for reducing parasitic capacitance and offset voltage errors by changing the integration order of multiple integrators.

[0009] One or more embodiments of this disclosure provide a fingerprint detection device and method for reducing the processing load of an amplifier by varying the integral processing in units of the drive cycle of the touch panel.

[0010] One or more embodiments of this disclosure provide a fingerprint detection device and method for increasing the number of points by adjusting a compensation value according to the points processing.

[0011] Additional aspects will be set forth in part in the description which follows, and will also be apparent in part from the description, or may be learned by practicing the embodiments presented in this disclosure.

[0012] According to one aspect of this disclosure, a fingerprint detection device is provided, comprising: a touch panel including a node array; an amplifier including: a first integrator and a second integrator, the first integrator being configured to amplify an electrical signal received from the touch panel into a first signal of a first polarity, and the second integrator being configured to amplify the electrical signal into a second signal of a second polarity, wherein the electrical signal changes according to a user's touch on the touch panel; and a processor configured to control the amplifier to perform a first integration process and a second integration process for a plurality of electrical signals received from a plurality of nodes of the touch panel, wherein, in the first integration process, the first integrator and the second integrator operate repeatedly multiple times in a first order starting from the first integrator during a first time period, and in the second integration process, the second integrator and the first integrator operate repeatedly multiple times in a second order starting from the second integrator during a second time period.

[0013] The processor can also be configured to control the amplifier to perform a second integral process after performing a first integral process on all the multiple electrical signals.

[0014] The second time period does not need to overlap with the first time period.

[0015] The second time period can be after the first time period.

[0016] The length of the first time period and the length of the second time period can be the same.

[0017] At least one of the first time period and the second time period can be the same as a single drive time period of the touch panel.

[0018] The touch panel may include: a plurality of first electrode lines arranged along a first direction; and a plurality of second electrode lines arranged along a second direction, the second direction intersecting the first direction; wherein, a plurality of nodes are areas where one of the second electrode lines intersects with a first electrode line.

[0019] The amplifier may also include a compensator configured to adjust the output value of at least one of the first integrator and the second integrator.

[0020] The compensator can also be configured to adjust the absolute value of the output value to a minimum.

[0021] The compensator may include: a charging current source configured to charge one of the first integrator and the second integrator using charge; and a discharging current source configured to release charge from the other of the first integrator and the second integrator.

[0022] The processor can also be configured to control the compensator to minimize the difference between the output value of the first integral processing and the output value of the second integral processing.

[0023] The processor can also be configured to control the compensator to adjust the output value with a first adjustment degree during the first integral processing and to adjust the output value with a second adjustment degree during the second integral processing, the second adjustment degree being different from the first adjustment degree.

[0024] The processor can also be configured to determine that the first adjustment degree is greater than the second adjustment degree based on the output value of the first integral processing being greater than the output value of the second integral processing.

[0025] Each of the first and second integrators includes an operational amplifier and a capacitor connected in parallel with the operational amplifier.

[0026] A common voltage can be applied to the inverting terminal of the operational amplifier included in the first integrator and the non-inverting terminal of the operational amplifier included in the second integrator.

[0027] The processor can also be configured to use the output values ​​of the first integral processing and the second integral processing to identify the user's fingerprint.

[0028] According to another aspect of this disclosure, a fingerprint detection method is provided, comprising: performing a first integration process, wherein a first integrator and a second integrator are sequentially and repeatedly operated multiple times starting from the first integrator during a first time period, wherein the first integrator amplifies each of a plurality of electrical signals received from a plurality of nodes of a touch panel into a first signal of a first polarity, and the second integrator amplifies each of the plurality of electrical signals into a second signal of a second polarity; performing a second integration process, wherein the second integrator and the first integrator are sequentially and repeatedly operated multiple times starting from the second integrator for each of the plurality of electrical signals during a second time period; and detecting a fingerprint of a user who has touched the touch panel based on the results of the first integration process and the second integration process.

[0029] After performing the first integration process on all the multiple electrical signals, the second integration process can be performed.

[0030] The second time period does not need to overlap with the first time period.

[0031] The second time period can be after the first time period.

[0032] The length of the first time period and the length of the second time period can be the same.

[0033] At least one of the first time period and the second time period can be the same as a single drive time period of the touch panel.

[0034] Performing at least one of the first integration processing and the second integration processing may further include: adjusting the output value of at least one of the first integrator and the second integrator.

[0035] Adjusting the output value can include minimizing the absolute value of the output value.

[0036] Adjusting the output value may include at least one of the following: charging either the first integrator or the second integrator with charge; and releasing charge from the other of the first integrator and the second integrator.

[0037] The first degree of adjustment of the output value when performing the first integral processing can be different from the second degree of adjustment of the output value when performing the second integral processing.

[0038] Adjusting the output value may include: adjusting the output value with a first adjustment degree during the first integration process, and adjusting the output value with a second adjustment degree during the second integration process, the second adjustment degree being different from the first adjustment degree.

[0039] Adjusting the output value may include: if the output value of the first integral processing is greater than the output value of the second integral processing, adjusting the first adjustment level to be greater than the second adjustment level.

[0040] According to another aspect of this disclosure, a fingerprint detection device is provided, comprising: an amplifier including: a first integrator and a second integrator, the first integrator being configured to amplify an electrical signal received from a touch panel into a first signal of a first polarity, and the second integrator being configured to amplify the electrical signal into a second signal of a second polarity, wherein the electrical signal changes according to a user's touch on the touch panel; a processor configured to control the amplifier to perform a first integration process and a second integration process on a plurality of electrical signals received from a plurality of nodes of the touch panel; and a compensator configured to adjust the output value of at least one of the first integrator and the second integrator.

[0041] According to another aspect of this disclosure, a fingerprint detection device is provided, comprising: a memory storing one or more instructions; and a processor configured to execute one or more instructions to perform the following operations: performing a first integration process by controlling a first integrator and a second integrator to operate sequentially and repeatedly multiple times from the first integrator during a first time period, wherein the first integrator amplifies each of a plurality of electrical signals received from a plurality of nodes of a touch panel into a first signal of a first polarity, and the second integrator amplifies each of the plurality of electrical signals into a second signal of a second polarity; performing a second integration process by controlling the second integrator and the first integrator to operate sequentially and repeatedly multiple times from the second integrator for each of the plurality of electrical signals during a second time period; and detecting a fingerprint of a user touching the touch panel based on the results of the first integration process and the second integration process. Attached Figure Description

[0042] The above and other aspects, features, and advantages of some embodiments of this disclosure will become clearer from the following description taken in conjunction with the accompanying drawings, in which:

[0043] Figure 1 This is a view showing a fingerprint detection device according to an example embodiment.

[0044] Figure 2 A touch panel according to an example embodiment of the present disclosure is shown.

[0045] Figure 3 This is a block diagram illustrating an example of a receiving circuit according to an exemplary embodiment.

[0046] Figure 4 This is a diagram showing an amplifier connected to a second electrode line according to an example embodiment.

[0047] Figure 5 It shows that it includes Figure 4 Each switch and specific node (e.g., C) in the multi-integrator shown ij The timing diagram of the voltage at point ().

[0048] Figure 6 This is a diagram showing an amplifier with parasitic capacitance and offset voltage difference.

[0049] Figure 7 This is a timing diagram illustrating the operational state of the multi-integrator at each time interval according to an example embodiment.

[0050] Figure 8 This is a timing diagram showing the output values ​​of the multi-integrator through the compensator according to an example embodiment.

[0051] Figure 9This is a flowchart illustrating an operation method of a fingerprint detection device according to an example embodiment.

[0052] Figure 10 This is a reference diagram illustrating integral processing according to an example embodiment. Detailed Implementation

[0053] Referring now to the embodiments, examples of which are illustrated in the accompanying drawings, wherein similar reference numerals throughout the drawings denote similar elements. In this respect, the presented embodiments may take different forms and should not be construed as limited to the description set forth herein. Therefore, the embodiments are described below only with reference to the accompanying drawings to explain various aspects. The term “and / or” as used herein includes any and all combinations of one or more of the related listed items. Expressions such as “at least one of…” modify the entire list of elements when preceding it, rather than individual elements within the list.

[0054] In the following description, exemplary embodiments will be illustrated with reference to the accompanying drawings. It should be understood that the following examples are intended to illustrate the technical content only and are not intended to limit or restrict the scope of the claims. Content that can be readily inferred by those skilled in the art from the detailed description and examples should be interpreted as falling within the scope of the claims.

[0055] As used herein, terms such as “comprising” or “including” should not be construed as including all the various elements or steps described in the specification, and it should be understood that certain components or steps may be excluded, or additional components or steps may be included. Terms such as “part” or “module” as described in the specification refer to a unit for performing at least one function or operation, and may be implemented in hardware or software, or a combination of hardware and software.

[0056] Furthermore, the terms used in this document, including ordinal numbers such as "first" and "second," may be used to describe various components, but these components should not be limited to these terms. These terms are used only for the purpose of distinguishing one component from other components.

[0057] Figure 1 This is a block diagram illustrating a fingerprint detection device 100 according to an example embodiment. (See reference...) Figure 1 The fingerprint detection device 100 includes a touch panel 110, a transmitting circuit 120, a receiving circuit 130, and a processor 140. Although in Figure 1 Only relevant components are shown in the fingerprint detection device 100, but those skilled in the art will understand that other general components may be further included. For example, the touch sensing device 100 may be a capacitive sensing device.

[0058] Figure 2A touch panel 110 according to an example embodiment is shown. (Reference) Figure 1 and Figure 2 The touch panel 110 includes a first electrode line TL and a second electrode line RL arranged in the touch area 111.

[0059] The first electrode line TL (i.e., TL1, TL2, TL3) m-1 and TL m The second electrode line RL (i.e., RL1, RL2, RL3) can be positioned in the touch area 111 and extend along the horizontal axis. n-1 and RL n The electrode line RL can be arranged to extend along the vertical axis in the touch area 111. The second electrode line RL can overlap with the first electrode line TL. The first electrode line TL and the second electrode line RL can be electrically insulated.

[0060] The first electrode line TL and the second electrode line RL are shown as lines. However, this disclosure is not limited thereto. For example, each of the second electrode lines RL may also include a predetermined pattern disposed between nodes where the first electrode lines TL and RL intersect. The aforementioned pattern may have various shapes, such as polygons, circles, etc. Similarly, each of the first electrode lines TL may also include a predetermined pattern disposed between the aforementioned nodes. The area where the first electrode lines and the second electrode lines intersect may be a node.

[0061] When a user's finger approaches the touch panel 110, the mutual capacitance between each of the first electrode line TL and the second electrode line RL of the touch panel 110 can change. For example, based on the characteristics of the fingerprint pattern of the user's finger, the mutual capacitance of each region (i.e., node) where the first electrode line TL and the second electrode line RL intersect in the touch panel 110 can change.

[0062] The first electrode line TL is connected to the drive line DL (i.e., DL1, DL2, DL3). m-1 and DL m The second electrode line RL is connected to the sensing line SL (i.e., SL1, SL2, SL3). n-1 and SL n The drive line DL and the sensing line SL can be connected to the receiving circuit 130.

[0063] Transmitting circuit 120 is connected to drive line DL. Transmitting circuit 120 is configured to apply voltage to drive line DL under the control of processor 140. For example, transmitting circuit 120 can sequentially provide pulse signals, including pulse sequences, to drive line DL.

[0064] Receiver circuit 130 is connected to sensing line SL. Receiver circuit 130 is configured to sense signals transmitted through sensing line SL under the control of processor 140. Receiver circuit 130 can convert the sensed signals into digital signals and send the digital signals to processor 140.

[0065] For example, to detect fingerprints, the transmitting circuit 120 can sequentially apply different driving signals to each of the first electrode lines TL. Furthermore, the receiving circuit 130 can receive electrical signals individually through each of the second electrode lines SL. For example, when measuring mutual capacitance C... 11 At this time, a drive signal can be applied only to the first electrode line TL1, and the electrical signal from the first electrode line RL1 can be measured. Similarly, when measuring the mutual capacitance C... mn At that time, only the m-th first electrode line TL m Apply a drive signal and measure the signal from the nth second electrode line RL. n The electrical signal.

[0066] The processor 140 can control the overall operation of the transmitting circuit 120 and the receiving circuit 130. For example, the processor 140 can control the amplitude, application time, etc. of the voltage pulses applied to each of the first electrode lines TL via the transmitting circuit 120. Moreover, the processor 140 can control the transmitting circuit 120 to apply voltage pulses to some of the first electrode lines TL.

[0067] The processor 140 can use the current or potential received by the receiving circuit 130 to generate and process image data related to a user's fingerprint. For example, the processor 140 can use the current or potential received by the receiving circuit 130 to generate and process fingerprint image data corresponding to a fingerprint region, and can generate and process feature point data by analyzing the pixel values ​​included in the image data.

[0068] Figure 3 This is a block diagram illustrating an example of a receiving circuit 130 according to an exemplary embodiment. (See reference...) Figure 1 and Figure 3 The receiving circuit 130 includes multiple detection units 131.

[0069] Each detection unit 131 may include a charge amplifier CA, a signal processor SP, an analog-to-digital converter ADC, and a filter FIR.

[0070] The charge amplifier CA can convert a signal (e.g., a current signal) received through the sensing line SL into a voltage signal.

[0071] A signal processor (SP) can process the output signal of a charge amplifier (CA). For example, the SP can demodulate the output signal of the charge amplifier (CA) and perform filtering. The SP can also convert the output signal of the charge amplifier (CA) into a direct current (DC) signal.

[0072] The analog-to-digital converter (ADC) can be configured to convert the output signal of the signal processor (SP) into a digital signal. The output signal of the ADC can be filtered in a filter (FIR). Furthermore, the filtered digital signal can be sent to the processor (140).

[0073] For example, charge amplifiers (CA) and signal processors (SP) can process analog signals, while filters (FIR) can process digital signals.

[0074] Furthermore, when the fingerprint detection device 100 is driven with a high-resolution sensing capability, the width of the first electrode line TL can be very narrow. When the width of the first electrode line TL becomes narrow, the area of ​​the node activated during mutual capacitance measurement becomes smaller. When the area of ​​the node to be activated becomes smaller, the strength of the obtained signal may decrease, and the amount of change in mutual capacitance measured at each node may be too small. Therefore, accurate measurement results may be difficult to obtain. Furthermore, when the layer (i.e., the cover layer) covering the first electrode line TL and the second electrode line SL of the touch panel 110 becomes thicker, the amount of change in mutual capacitance at the nodes may be small depending on the user's touch. In this case, accurate measurement may be difficult. Therefore, the amplifier CA of the fingerprint detection device 100 according to the embodiment may include multiple integrators.

[0075] Figure 4 This illustrates a connection to a second electrode line RL according to an embodiment. j A diagram of amplifier CA is shown. For example, the j-th amplifier CA of receiver circuit 130 can be electrically connected to the second electrode line RL. j And the first electrode lines TL (i.e., TL1, TL2, TL3) m-1 and TL m The mutual capacitance can be amplified sequentially according to the driving signal. For example, the j-th amplifier CA of the receiving circuit 130 can be amplified through the sensing line SL. j Connect to the second electrode line RL j and the first electrode lines TL (i.e., TL1, TL2, TL3) m-1 and TL m ),refer to Figure 4 The final output signal of amplifier CA can be defined as the potential difference between the first output terminal OUT1 and the second output terminal OUT2 shown in the figure.

[0076] The amplifier CA may include an integrating circuit 210 that amplifies the electrical signal received from the touch panel 110 into a signal with different polarities. According to an example embodiment, the integrating circuit 210 may have multiple integrators for amplifying the electrical signal received from the touch panel 110. For example, the integrating circuit 210 may include a first integrator 212 for amplifying the electrical signal received from the touch panel 110 into a negative signal and a second integrator 214 for amplifying the electrical signal received from the touch panel 110 into a positive signal. The first integrator 212 may be connected to a first output terminal OUT1, and the second integrator 214 may be connected to a second output terminal OUT2. According to an example embodiment, the multiple integrators may operate independently to amplify the electrical signal received from the touch panel 110.

[0077] Each of the first integrator 212 and the second integrator 214 may include operational amplifiers OA1 and OA2 and reset switches SR1 and SR2. According to an example embodiment, operational amplifiers OA1 and OA2 are connected in parallel. Additionally, amplifier CA may include a sensor line SL. j The first switch S1 connected to the first integrator 212 and the sensing line SL j The second switch S2 is connected to the second integrator 214.

[0078] Specifically, the inverting input terminal (-) of the first operational amplifier OA1 of the first integrator 212 and the sensing line SL j They can be connected to each other via the first switch S1. According to an example embodiment, the sensing lines SL... j Connect to a second electrode line RL i The second electrode line RL j The terminals are connected to the capacitors that form mutual capacitance. Furthermore, the inverting input terminal (-) and the first output terminal OUT1 of the first operational amplifier OA1 can be connected through the first capacitor C. S1 They are interconnected. Furthermore, the inverting input terminal (-) and the first output terminal OUT1 of the first operational amplifier OA1 can be connected via the first reset switch S. R1 They are connected to each other. The reference voltage Vcom can be connected to the non-inverting input terminal (+) of the first operational amplifier OA1.

[0079] The inverting input terminal (-) of the second operational amplifier OA2 and the sensing line SL j They can be connected to each other via the second switch S2. Furthermore, the inverting input terminal (-) and the second output terminal OUT2 of the second operational amplifier OA2 can be connected via the second capacitor C. s2 They are connected to each other. Then, the inverting input terminal (-) and the second output terminal OUT2 of the second operational amplifier OA2 can be connected via the second reset switch S. R2They are interconnected. The reference voltage Vcom can be connected to the non-inverting input terminal (+) of the second operational amplifier OA2.

[0080] In this case, the first capacitor C S1 Second capacitor C S2 It can be used to accumulate and store the flow through the sensing line SL j An integral capacitor with charge.

[0081] Processor 140 can control the first switch S1, the second switch S2, and the first reset switch S1. R1 Second reset switch S R2 The operating status.

[0082] Figure 5 It shows that it includes Figure 4 Each switch and specific node (e.g., C) in the shown integrator circuit 210 ij The timing diagram of the voltage at point (). Figure 5 In the diagram, the horizontal axis represents a time period.

[0083] Figure 5 The first output voltage V at the output terminal of the first operational amplifier OA1 according to the time period is shown. OUT1 and the second output voltage V at the output terminal of the second operational amplifier OA2 according to the time period OUT2 The curve (a).

[0084] also, Figure 5 The diagram shows the control of the first reset switch S. R1 Second reset switch S R2 Timing diagram (b) of the reset signal for the on / off state, and the first electrode line TL i Potential V Ti The timing diagram (c) shows the timing diagram (d) showing the signals used to control the on / off state of the first switch S1, and the timing diagram (e) shows the timing diagram (e) showing the signals used to control the on / off state of the second switch S2.

[0085] After a reset signal is applied to the first integrator 212 and the second integrator 214, an on signal is applied to the first electrode line TL. i In this state, when the first switch S1 is turned on and the second switch S2 is turned off, the first operational amplifier OA1 is driven to release the first capacitor C. S1 The charge Q in the middle. Due to the release of the charge, as the corresponding charge decreases at the first output terminal OUT1, such as Figure 5 As shown in the curve (a), an output signal with a dashed waveform is generated at the first output terminal OUT1.

[0086] Furthermore, when the turn-on signal is applied to the first electrode line TL i In the state where the first switch S1 is open and the second switch S2 is closed, the second operational amplifier OA2 is driven to control the second capacitor C. S2 Charging. Due to the accumulation of charge, as the corresponding charge increases at the second output terminal OUT2, such as... Figure 5 As shown in the curve (a), an output signal with a solid waveform is generated at the second output terminal OUT2.

[0087] like Figure 5 As shown in graph (a), when the first switch S1 and the second switch S2 are sequentially switched on / off N times (where N is an integer), the charge is repeatedly released and accumulated N times, and the magnitude of the output signal increases. As described above, since multiple integrators are driven alternately, it can be seen that the integration effect is the same as the difference OP1 between the output signals between the first output terminal OUT1 and the second output terminal OUT2, so the output dynamic range can be increased.

[0088] Specifically, if the two integrators are driven alternately, the difference in the output value of amplifier CA can be analogous to the difference in signal due to the depth difference between the ridges of the fingerprint. Therefore, as the number of integrations increases, the signal difference between the ridges of the fingerprint can be obtained, thereby mitigating the inaccuracies caused by the thickness of the thick overlay and the width of the electrode lines.

[0089] Additionally, the input electrical signal of amplifier CA may include the capacitance of nodes other than the corresponding nodes in touch panel 110, or, in addition to the "sensing capacitance C" formed between nodes corresponding to the touch of an object, the parasitic capacitance Cp formed in any region of the metallic material of fingerprint detection device 100 in receiving circuit 130. If there is no finger of an object near the second electrode line SL, the value of the "sensing capacitance" may be close to zero, but the input signal of parasitic capacitance Cp can still be applied to the input terminal of amplifier CA. Parasitic capacitance Cp can cause voltage saturation of the first integrator 212 and the second integrator 214 to limit the number of integrations of integrator circuit 210.

[0090] Furthermore, when processing the components of amplifier CA, an offset voltage difference ΔV may occur between the first operational amplifier OA1 and the second operational amplifier OA2 due to processing variations. That is, amplifier CA can operate as if different potentials were applied to the non-inverting input terminal (+) of the first operational amplifier OA1 and the non-inverting input terminal (+) of the second operational amplifier OA2.

[0091] Figure 6 This is a diagram showing an amplifier CA' with parasitic capacitance Cp and offset voltage difference ΔV.

[0092] During the operation of amplifier CA, even when the same reference voltage Vcom is applied to the non-inverting input terminals (+) of the first operational amplifier OA1 and the second operational amplifier OA2, due to the deviation between each of operational amplifiers OA1 and OA2, the non-inverting input terminals (+) of the first operational amplifier OA1 and the second operational amplifier OA2 can operate as if substantially different potentials Vcom and Vcom+ΔV were applied. Figure 7 As shown, the non-inverting input terminal (+) of the first operational amplifier OA1 operates as if Vcom were substantially applied, while the non-inverting input terminal (+) of the second operational amplifier OA2 can operate as if Vcom+ΔV were substantially applied.

[0093] Thus, due to the processing discrepancy between operational amplifiers OA1 and OA2, errors may occur in the output signal of the integrator. To eliminate these errors, amplifier CA according to the embodiment can perform integration processing to obtain the output value of amplifier CA by changing the operating sequence of the first switch S1 and the second switch S2. By using the values ​​obtained by the two processors 140, information about the touch input can be obtained.

[0094] Figure 7 This is a timing diagram showing the operating state of the integrator circuit 210 for each time period according to an embodiment.

[0095] exist Figure 7 In the first time period T 1i Second time period T 2i During this period, the first integral processing and the second integral processing are performed respectively.

[0096] The first integration process can be performed as follows: the electrical signal received from the touch panel 110 is amplified by the first integrator 212, and then the amplified electrical signal is amplified by the second integrator 214. Therefore, in the first integration process, if the first switch S1 and the second switch S2 successively undergo one transition from an off state to an on state to an off state, then one integration count is completed.

[0097] Specifically, immediately following operational amplifiers OA1 and OA2 in the first time period T 1i After being reset, for each integral count in the first integral processing, the on / off states of the first switch S1 and the second switch S2 can be switched in sequence. For example, in the first time period T 1i Central first electrode line TL i When a signal is applied, and the first switch S1 is closed while the second switch S2 is open, the first operational amplifier OA1 is driven to output power from the first capacitor C. S1Release the charge. Due to the release of the charge, as the corresponding charge decreases at the first output terminal OUT1, such as... Figure 7 As shown, an output signal with the dashed waveform is generated at the first output terminal OUT1.

[0098] Then, the turn-on signal is applied to the first electrode line TL i In the state where the first switch S1 is open and the second switch S2 is closed, the second operational amplifier OA2 is driven to control the second capacitor C. S2 Charging. Due to the accumulation of charge, as the corresponding charge increases at the second output terminal OUT2, such as... Figure 7 As shown, an output signal with a solid waveform is generated at the second output terminal OUT2.

[0099] The first integrator processor 140 can repeat its operation multiple times in the order of the first integrator 212 to the second integrator 214. Figure 7 In this system, the first integrator is composed of two integrator counters.

[0100] The second integration process can refer to the following operation: the electrical signal received from the touch panel 110 is amplified by the second integrator 214, and then the amplified electrical signal is amplified by the first integrator 212. Therefore, in the second integration process, if the second switch S2 and the first switch S1 successively undergo one transition from an off state to an on state to an off state, then one integration count is completed. The second integration processor 140 can repeat the operation multiple times in the order from the second integrator 214 to the first integrator 212.

[0101] Specifically, immediately after operational amplifiers OA1 and OA2 are reset in the second time period T2i, the on / off state can be switched in sequence with the second switch S2 and the first switch S1 for each integration count of the second integration process. For example, in the second time period T... 2i Central first electrode line TL i When a signal is applied, and the second switch S2 is closed while the first switch S1 is open, the second operational amplifier OA2 is driven to output power from the first capacitor C. s1 Release the charge. Due to the release of the charge, the corresponding charge decreases at the second output terminal OUT2, such as... Figure 7 As shown, an output signal with a solid waveform is generated at the second output terminal OUT2.

[0102] Then, in the first electrode line TL i When the on signal is applied, and the second switch S2 is open and the first switch S1 is closed, the first operational amplifier OA1 is driven to control the first capacitor C. s1Charging. Due to the accumulation of charge, as the corresponding charge increases at the first output terminal OUT1, such as... Figure 7 As shown, an output signal with the dashed waveform is generated at the first output terminal OUT1.

[0103] In the second integrator processor 140, the second integrator 214 and the first integrator 212 can be operated sequentially and repeatedly multiple times. Figure 7 In the process, the two integral counts form the second integral process.

[0104] The output values ​​OP1 and OP2 of both the first and second integral processing are affected by parasitic capacitance Cp and offset voltage difference ΔV. For example, the output value OP1 of the first integral processing increases due to parasitic capacitance Cp and offset voltage difference ΔV, while the output value OP2 of the first integral processing decreases due to parasitic capacitance Cp and offset voltage difference ΔV. Therefore, the parasitic capacitance Cp and offset voltage difference ΔV can be eliminated by using both the output values ​​OP1 and OP2 of the first and second integral processing. For example, the sum or average of the output values ​​OP1 and OP2 of the first and second integral processing can be determined as the output value of amplifier CA.

[0105] Furthermore, even using the first and second integration processes, each integration process is still affected by the parasitic capacitance Cp and the offset voltage difference ΔV, thus limiting the ability to increase the integration count. Figure 7 In this process, the integral count can be limited by the output value of the first integrator 140.

[0106] When each of the first and second integration processes is performed, the integration count can be increased by adjusting the output value. The amplifier CA according to the embodiment may also include a compensator 220 that adjusts at least one output value, i.e., an output value, of the first and second integration processes.

[0107] Refer again Figure 4 The amplifier CA may also include a compensator 220 that applies a constant current to the first integrator 212 and the second integrator 214. The compensator 220 may include: a discharge current source 222 for discharging charge to either the first integrator 212 or the second integrator 214; a charging current source 224 for charging the other of the first integrator 212 and the second integrator 214; a third switch S3 connecting the discharge current source 222 and the integrator circuit 210; and a fourth switch S4 connecting the charging current source 224 and the integrator circuit 210.

[0108] Processor 140 can control the output value of integrator 210 by accumulating or releasing charge in integrator 210 through controlling first switch S1 and second switch S2. Processor 140 can control compensator 220 such that the change in the output value of integrator 210 is small relative to the integral count. Processor 140 can perform synchronization such that the first switch S1 and second switch S2 connected to integrator 210 and the third switch S3 and fourth switch S4 connected to compensator 220 are synchronized with each other, and the directions (i.e., signs) of the current input to integrator 210 and the current input to compensator 220 become the same. Then, the rising width at the rising edge of the output value of integrator 210 can be small, and the falling width at the falling edge can be small.

[0109] Figure 8 This is a timing diagram showing the output value of the integrator circuit 210 through the compensator 220 according to an embodiment.

[0110] Figure 8 The first output voltage V at the output terminal of the first operational amplifier OA1 according to the time period is shown. OUT1 and the second output voltage V at the output terminal of the second operational amplifier OA2 according to the time period OUT2 The curve (a).

[0111] Figure 8 The diagram shows the control of the first reset switch S. R1 Second reset switch S R2 Timing diagram of the on / off state signal (b), first electrode line TL i Potential V Ti The timing diagrams shown are as follows: (g), (h), (i), (j), (k), and (j), (h), (i), (j ...

[0112] The signal of the third switch S3 can be synchronized with the signal of the first switch S1, and the signal of the fourth switch S4 can be synchronized with the signal of the second switch S2. At this time, the duration of the on state of the third switch S3 can be shorter than the duration of the on state of the first switch S1, and the duration of the on state of the fourth switch S4 can be shorter than the duration of the on state of the second switch S2.

[0113] After a reset signal is applied to the first integrator 212 and the second integrator 214, an on signal is applied to the first electrode line TL. iIn the state where the first switch S1 and the third switch S3 are closed and the second switch S2 and the fourth switch S4 are open, the signal from the sensing line SL... j The current is distributed to the integrator 210 and the compensator 220. Therefore, even when the first operational amplifier OA1 is driven, the current from the first capacitor C... S1 The amount of charge released is also relatively small, thereby reducing the degree of charge reduction in the first output terminal OUT1.

[0114] Next, the turn-on signal is applied to the first electrode line TL. i In the state where the first switch S1 and the third switch S3 are open and the second switch S2 and the fourth switch S4 are closed, the signal from the sensing line SL... j The current is distributed to the integrator 210 and the compensator 220. Therefore, even when the second operational amplifier OA2 is driven, the second capacitor C... s2 The amount of charge stored in the middle is also relatively small, thereby reducing the degree of charge increase in the second output terminal OUT2.

[0115] According to the example embodiment, since the output value of the integrator circuit 210 can be adjusted to be smaller by the compensator 220, the integration count of the integrator circuit 210 can be increased. The degree to which the output value of the integrator circuit is adjusted can be called the compensation value. The compensation value can be adjusted by the magnitude of the currents of the discharge current source 222 and the charging current source 224. For example, when the discharge or charging currents of the discharge current source 222 and the charging current source 224 are large, the compensation value can be large.

[0116] Compensator 220 can apply the same or different compensation values ​​to the first integration process and the second integration process, wherein the first integration process performs integration in the order of first integrator 212 and second integrator 214, and the second integration process performs integration in the order of second integrator 214 and first integrator 212. For example, if the change in the output value of the first integration process is greater than the change in the output value of the second integration process, the compensation value applied to the first integration process can be greater than the compensation value applied to the second integration process. Then, as an alternative to applying the same compensation value, the integration count can be increased.

[0117] Simultaneously, in order to apply different compensation values, the current values ​​of the charging current source 224 and the compensation current source of the compensator 220 must be adjusted. When the first integration process and the second integration process are performed consecutively on a node, the processing load of the receiving circuit 130 can be increased. Therefore, according to the embodiment, at least one amplifier CA included in the receiving circuit 130 performs the first integration process on multiple nodes electrically connected to each amplifier CA, and then performs the second integration process.

[0118] Figure 9This is a flowchart illustrating the operation method of the fingerprint detection device 100 according to an embodiment.

[0119] The processor 140 can control the amplifier CA to perform a first integration process (S910) on each electrical signal received from a plurality of nodes of the touch panel 110 during a first time period. Each of the plurality of amplifiers CA can be electrically connected to a corresponding second electrode line via a corresponding sensing line. Each second electrode line can intersect with a plurality of first electrode lines to form a plurality of nodes. The amplifier CA can apply an electrical signal from each node in response to a drive signal applied via a drive line.

[0120] Each amplifier CA may include a first integrator 212 for amplifying the applied electrical signal into a signal of a first polarity and a second integrator 214 for amplifying the applied electrical signal into a signal of a second polarity opposite to the first polarity. During the execution of the first integration process, the processor 140 repeatedly operates the first integrator 212 and the second integrator 214 in sequence multiple times during a first time period, thereby controlling the amplifier CA to perform the first integration process.

[0121] Processor 140 can control amplifier CA to perform a second integration process on each of the multiple electrical signals received from multiple nodes of touch panel 110 during a second time period (S920). The second integration process may refer to the first integrator 212 and the second integrator 214 operating repeatedly in the order of second integrator 214 and first integrator 212. The second time period does not overlap with the first time period, and the second time period may be the next time period after the first time period. Therefore, the second integration process can be performed after the first integration process is performed on all the multiple electrical signals received from multiple nodes.

[0122] The lengths of the first time period and the second time period can be the same. For example, the first time period and the second time period can be the same as the driving time period of the touch panel 110. The driving time period of the touch panel 110 can be the time used to apply a driving signal to all of the plurality of first electrode lines of the touch panel 110.

[0123] Simultaneously, while performing at least one of the first and second integration processes, the processor 140 can control the amplifier CA such that the output value of at least one of the first integrator 212 and the second integrator 214 is adjusted. The amplifier CA may also include a compensator 220 for adjusting the output value of at least one of the first integrator 212 and the second integrator 214, and the compensator 220 can control the absolute value of the output value of the integrating circuit 210 to be small. For example, the compensator 220 may include a charging current source 224 for charging either the first integrator 212 or the second integrator 214, and a discharging current source 222 for releasing charge from the other of the first integrator 212 and the second integrator 214.

[0124] The processor 140 can control the compensator 220 to minimize the difference between the output value of the first integral processing and the output value of the second integral processing. For example, the processor 140 can control the compensator 220 to minimize the difference between the output value of the first integral processing and the output value of the second integral processing. Specifically, the processor 140 can control the compensator 220 such that a first adjustment degree of the amplifier CA's output value during the first integral processing differs from a second adjustment degree of the amplifier CA's output value during the second integral processing. For example, when the magnitude of the output value according to the first integral processing is greater than the magnitude of the output value according to the second integral processing, the processor 140 can determine that the first adjustment degree is greater than the second adjustment degree.

[0125] Processor 140 can identify a user's fingerprint using the output value based on the first integration processing and the output value based on the second integration processing (S930). For example, amplifier CA of receiving circuit 130 can output a voltage signal, which is the output value amplified by performing the first integration processing during a first time period. Signal processor converts the amplified voltage signal into a DC signal, and analog-to-digital converter converts the DC-converted signal into a digital signal and sends the digital signal to processor 140. Similarly, during a second time period (the time period following the first time period), amplifier CA of receiving circuit 130 performs the second integration processing to output a voltage signal (i.e., the amplified output value), and this voltage signal can be converted into a digital signal by signal processor, analog-to-digital converter, etc., and sent to processor 140.

[0126] The processor 140 can identify a user's fingerprint by using the digitally converted output value of a first integral processing during a first time period and the output value of a second integral processing during a second time period. During the first time period, the output value of the first integral processing may include the output values ​​of the first integral processing for multiple nodes, and during the second time period, the output value of the second integral processing may also include the output values ​​of the first integral processing for multiple nodes. The processing can classify the output values ​​of the first and second integral processing corresponding to each node and obtain a fingerprint image after determining the pixel value of each node using the output values ​​of the first and second integral processing corresponding to each node.

[0127] Figure 10 This is a reference diagram illustrating the integral processing according to an embodiment.

[0128] like Figure 10 As shown, processor 140 controls amplifier CA to perform a first integration process on multiple nodes during a first time period T1, and controls amplifier CA to perform a second integration process on the same multiple nodes during a second time period T2. Here, the lengths of the first time period T1 and the second time period T2 can be the same as the driving time period of touch panel 110. During the first time period T1, amplifier CA can amplify the electrical signals received from the multiple nodes connected to amplifier CA. For example, when touch panel 110 consists of m×n nodes, and amplifier CA is connected to each second electrode line SL... j At that time, each amplifier CA can amplify the electrical signals received from m nodes.

[0129] If no compensation value is applied to the amplifier CA, then due to the parasitic capacitance Cp and the offset voltage difference, such as Figure 10 As shown, the difference between the value output from amplifier CA during the first time period and the value output from amplifier CA during the second time period may be large.

[0130] According to the example embodiment, the processor 140 can apply a compensation value when amplifying the electrical signal received from the node. Then, as the output value of the integral processed according to the first integral process increases, when the amplifier CA performs the first integral process, the processor 140 controls the compensator 220 to compensate with a large compensation value. When the amplifier CA performs the second integral process, the processor 140 controls the compensator 220 to compensate with a small compensation value.

[0131] Therefore, as the output value of the compensation amplifier CA decreases, the amplifier CA can perform more integration processing. Furthermore, the compensation value of the aforementioned compensator 220 is constant and can be removed by the receiving circuit 130 or the processor 140 after the amplifier during signal processing.

[0132] Those skilled in the art who are familiar with this embodiment will understand that this disclosure can be implemented in modified forms without departing from the essential characteristics of this embodiment. Therefore, the disclosed embodiments should be considered descriptive only and not for limiting purposes. The scope is specified in the claims rather than in the foregoing description, and all differences within the equivalent scope should be interpreted as included within the disclosure.

[0133] Elements of the fingerprint detection device described herein can be implemented using hardware and software components. For example, hardware components may include amplifiers, bandpass filters, analog-to-digital converters, non-transitory computer memory, and processing devices. The processing device can be implemented using one or more general-purpose or special-purpose computers (e.g., processors, controllers, and arithmetic logic units (ALUs), digital signal processors, microcomputers, field-programmable gate arrays (FPGAs), programmable logic units (PLUs), microprocessors, or any other device capable of responding to and executing instructions in a defined manner). The processing device may run an operating system (OS) and one or more software applications running on the OS. The processing device may also access, store, manipulate, process, and create data in response to the execution of the software. For simplicity, the singular is used to describe the processing device; however, those skilled in the art will understand that the processing device may include multiple processing elements and various types of processing elements. For example, the processing device may include multiple processors or a processor and a controller. Furthermore, different processing configurations are possible, such as parallel processors.

[0134] Software can include computer programs, code, instructions, or combinations thereof, to independently or uniformly instruct or configure processing equipment to operate as needed. Software and data can be permanently or temporarily embodied in any type of machine, component, physical or virtual device, computer storage medium, or device, or in propagated signal waves capable of providing instructions or data to or being interpreted by the processing equipment. Software can also be distributed across network-coupled computer systems, enabling distributed storage and execution of the software. Software and data can be stored on one or more non-transitory computer-readable recording media. Non-transitory computer-readable recording media can include any data storage device capable of storing data that can subsequently be read by the computer system or processing equipment.

[0135] The example embodiments include non-transitory computer-readable media, which include program instructions to implement various operations embodied by a computer. The media may also include data files, data structures, tables, etc., alone or in combination with program instructions. The media and program instructions may be media and program instructions specifically designed and constructed for the purposes of the example embodiments, or they may be media and program instructions publicly available and usable by those skilled in the art of computer software. Examples of non-transitory computer-readable media include magnetic media such as hard disks, floppy disks, and magnetic tapes; optical media such as CD-ROMs; magneto-optical media such as floppy disks; and hardware devices such as read-only memory (ROM) and random access memory (RAM) specifically configured to store and execute program instructions. Examples of program instructions include both machine code (e.g., machine code generated by a compiler) and files containing higher-level code that can be executed by a computer using an interpreter. The described hardware devices may be configured to function as one or more software modules to perform the operations of the example embodiments described above, or vice versa.

Claims

1. A fingerprint detection device, comprising: Touch panel, including a node array; An amplifier includes: a first integrator and a second integrator, the first integrator being configured to amplify an electrical signal received from the touch panel into a first signal of a first polarity, and the second integrator being configured to amplify the electrical signal into a second signal of a second polarity, wherein the electrical signal changes according to a user's touch on the touch panel; and The processor is configured to control the amplifier to perform a first integration process and a second integration process on multiple electrical signals received from multiple nodes of the touch panel. In the first integration process, the first integrator and the second integrator repeatedly operate multiple times in a first order starting from the first integrator during a first time period after the first reset, and in the second integration process, the second integrator and the first integrator repeatedly operate multiple times in a second order starting from the second integrator during a second time period after the second reset.

2. The fingerprint detection device according to claim 1, wherein, The processor is further configured to control the amplifier to perform the second integration process after performing the first integration process on all of the plurality of electrical signals.

3. The fingerprint detection device according to claim 1, wherein, The second time period does not overlap with the first time period.

4. The fingerprint detection device according to claim 1, wherein, The second time period is after the first time period.

5. The fingerprint detection device according to claim 1, wherein, The length of the first time period is the same as the length of the second time period.

6. The fingerprint detection device according to claim 1, wherein, At least one of the first time period and the second time period is the same as one driving time period of the touch panel.

7. The fingerprint detection device according to claim 1, wherein, The touch panel includes: Multiple first electrode lines are arranged along a first direction; and Multiple second electrode lines are arranged along a second direction, which intersects the first direction. The plurality of nodes are the regions where one of the plurality of second electrode lines intersects with the plurality of first electrode lines.

8. The fingerprint detection device according to claim 1, wherein, The amplifier further includes a compensator configured to adjust the output value of at least one of the first integrator and the second integrator.

9. The fingerprint detection device according to claim 8, wherein, The compensator is also configured to adjust the absolute value of the output value to a minimum.

10. The fingerprint detection device according to claim 8, wherein, The compensator includes: A charging current source is configured to charge one of the first integrator and the second integrator using electrical charge; and A discharge current source is configured to release charge from another of the first integrator and the second integrator.

11. The fingerprint detection device according to claim 8, wherein, The processor is also configured to control the compensator to minimize the difference between the output value of the first integral processing and the output value of the second integral processing.

12. The fingerprint detection device according to claim 8, wherein, The processor is further configured to: control the compensator to adjust the output value with a first adjustment degree during the first integral processing and to adjust the output value with a second adjustment degree during the second integral processing, the second adjustment degree being different from the first adjustment degree.

13. The fingerprint detection device according to claim 12, wherein, The processor is further configured to determine that the first adjustment degree is greater than the second adjustment degree based on the fact that the output value of the first integral processing is greater than the output value of the second integral processing.

14. The fingerprint detection device according to claim 1, wherein, Each of the first integrator and the second integrator includes an operational amplifier and a capacitor connected in parallel with the operational amplifier.

15. The fingerprint detection device according to claim 14, wherein, A common voltage is applied to the inverting terminal of the operational amplifier included in the first integrator and the non-inverting terminal of the operational amplifier included in the second integrator.

16. The fingerprint detection device according to claim 1, wherein, The processor is also configured to use the output value of the first integral processing and the output value of the second integral processing to identify the user's fingerprint.

17. A fingerprint detection method, comprising: A first integration process is performed, in which a first integrator and a second integrator operate sequentially and repeatedly multiple times during a first time period after a first reset, starting from the first integrator. In this process, the first integrator amplifies each of a plurality of electrical signals received from a plurality of nodes of the touch panel into a first signal of a first polarity, and the second integrator amplifies each of the plurality of electrical signals into a second signal of a second polarity. Perform a second integration process, in which the second integrator and the first integrator operate sequentially and repeatedly multiple times for each of the plurality of electrical signals, starting from the second integrator, during a second time period after the second reset; and Based on the results of the first integration processing and the second integration processing, the fingerprint of the user who touched the touch panel is detected.

18. The method according to claim 17, wherein, After performing the first integration process on all of the plurality of electrical signals, the second integration process is performed.

19. The method of claim 17, wherein, The second time period does not overlap with the first time period.

20. The method of claim 17, wherein, The second time period is after the first time period.

21. The method according to claim 17, wherein, The length of the first time period is the same as the length of the second time period.

22. The method according to claim 17, wherein, At least one of the first time period and the second time period is the same as one driving time period of the touch panel.

23. The method according to claim 17, wherein, Performing at least one of the first integration process and the second integration process further includes: adjusting the output value of at least one of the first integrator and the second integrator.

24. The method according to claim 23, wherein, Adjusting the output value includes: adjusting the absolute value of the output value to the minimum.

25. The method according to claim 23, wherein, Adjusting the output value includes at least one of the following: Charge either the first integrator or the second integrator using electrical charge; and Release charge from the other of the first integrator and the second integrator.

26. The method of claim 24, wherein, The first degree of adjustment of the output value when performing the first integral processing is different from the second degree of adjustment of the output value when performing the second integral processing.

27. The method according to claim 26, wherein, Adjusting the output value includes: adjusting the output value with a first adjustment degree during the first integration process, and adjusting the output value with a second adjustment degree during the second integration process, the second adjustment degree being different from the first adjustment degree.

28. The method according to claim 27, wherein, Adjusting the output value includes: adjusting the first adjustment level to be greater than the second adjustment level based on the fact that the output value of the first integral processing is greater than the output value of the second integral processing.

29. A fingerprint detection device, comprising: An amplifier includes: a first integrator and a second integrator, the first integrator being configured to amplify an electrical signal received from a touch panel into a first signal of a first polarity, and the second integrator being configured to amplify the electrical signal into a second signal of a second polarity, wherein the electrical signal changes according to a user's touch on the touch panel; and The processor is configured to control the amplifier to perform a first integral processing and a second integral processing on multiple electrical signals received from multiple nodes of the touch panel; and A compensator is configured to adjust the output value of at least one of the first integrator and the second integrator. In the first integration process, the first integrator and the second integrator repeatedly operate multiple times in a first order starting from the first integrator during a first time period after the first reset, and in the second integration process, the second integrator and the first integrator repeatedly operate multiple times in a second order starting from the second integrator during a second time period after the second reset.

30. A fingerprint detection device, comprising: Memory, which stores one or more instructions; as well as The processor is configured to execute one or more instructions to perform the following operations: The first integration process is performed by controlling the first integrator and the second integrator to operate sequentially and repeatedly multiple times during a first time period after the first reset, starting from the first integrator. The first integrator amplifies each of a plurality of electrical signals received from a plurality of nodes of the touch panel into a first signal of a first polarity, and the second integrator amplifies each of the plurality of electrical signals into a second signal of a second polarity. The second integration process is performed by controlling the second integrator and the first integrator to operate sequentially and repeatedly multiple times for each of the plurality of electrical signals, starting from the second integrator, during a second time period after the second reset; and Based on the results of the first integration processing and the second integration processing, the fingerprint of the user who touched the touch panel is detected.

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