Fingerprint module and electronic equipment

Abstract

The embodiment of the invention provides a fingerprint module and electronic equipment. The fingerprint module comprises a sensing unit and a plurality of recognition units, the plurality of identification units are electrically connected with different identification areas on the induction unit respectively, at least one filter resistor is arranged in each identification unit, the at least one filter resistor is electrically connected with the induction unit, and at least part of the filter resistors and the induction unit form a first filter circuit; the sensing unit is used for generating an electric signal when a to-be-recognized object presses a recognition area; and the identification units are used for converting the electric signals filtered by the first filter circuit into identification signals and sending the identification signals to a processing unit of the electronic equipment, so that the processing unit carries out fingerprint identification according to the identification signals sent by the plurality of identification units. The fingerprint module provided by the embodiment of the invention is less interfered by an external signal in a fingerprint identification process.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of fingerprint modules, and in particular to a fingerprint module and an electronic device. Background Art

[0002] With the development of smart devices, fingerprint recognition has become the mainstream security solution for smart devices. The side fingerprint solution is installed in a different position from the traditional front and back fingerprint solution. The traditional front and back fingerprint solution needs to occupy the structural space on the front or back of the smart device, while the side fingerprint solution is set on the side of the middle frame of the smart device, avoiding the fingerprint module occupying the structural space on the front or back, and can meet the space requirements of smart devices.

[0003] Currently, the side fingerprint module adopts a capacitive fingerprint recognition solution. After the finger is pressed on the recognition area of ​​the fingerprint module, the fingerprint module performs fingerprint recognition based on the difference in equivalent capacitance between the valleys and ridges of the finger's fingerprint.

[0004] However, when the side fingerprint module is used in electronic devices, some external signals are coupled to the fingerprint module through the finger, causing the fingerprint module to be interfered with by the external signals and affecting the fingerprint recognition function. Summary of the Invention

[0005] In view of this, embodiments of the present application provide a fingerprint module and an electronic device to at least partially solve the above problems.

[0006] According to a first aspect of an embodiment of the present application, a fingerprint module is provided for use in an electronic device, the fingerprint module comprising: a sensing unit and a plurality of identification units; the plurality of identification units are electrically connected to different identification areas on the sensing unit, respectively; the identification unit is provided with at least one filter resistor, the at least one filter resistor is electrically connected to the sensing unit, and at least some of the filter resistors and the sensing unit form a first filter circuit; the sensing unit is configured to generate an electrical signal when an object to be identified is pressed on an identification area; the identification unit is configured to convert the electrical signal filtered by the first filter circuit into an identification signal, and send the identification signal to a processing unit of the electronic device, so that the processing unit performs fingerprint identification based on the identification signals sent by the plurality of identification units.

[0007] In one possible implementation, the sensing unit includes a first electrode layer and a second electrode layer; the first electrode layer and the second electrode layer are electrically connected to the identification unit respectively, the identification area is located on the first electrode layer, and the at least one filter resistor is electrically connected to the first electrode layer; the first electrode layer is used to form a first capacitance with the object to be identified when the object to be identified is pressed on the identification area, so as to generate the electrical signal according to the first capacitance; the second electrode layer is used to prevent parasitic capacitance from being generated between the first electrode layer and the identification unit.

[0008] In one possible implementation, the identification unit includes a power supply unit, an integration subunit and the at least one filter resistor; the power supply unit is electrically connected to the sensing unit, the sensing unit is electrically connected to the integration subunit, the at least one filter resistor is electrically connected to the sensing unit, and at least part of the filter resistor is arranged between the sensing unit and the integration subunit, and the sensing unit and the filter resistor arranged between the sensing unit and the integration subunit form the first filtering circuit; the power supply unit is used to provide a power supply voltage to the sensing unit, so that when the object to be identified is pressed on the identification area, the sensing unit generates the electrical signal based on the power supply voltage; the integration subunit is used to generate the identification signal based on the electrical signal after filtering by the first filtering circuit.

[0009] In a possible implementation, the power supply subunit includes a digital-to-analog converter, a first switch, a second switch, a third switch, a fourth switch, and a fifth switch; the output end of the digital-to-analog converter is connected to the second end of the first switch, the first end of the first switch is connected to the sensing unit, the first end of the second switch, and the second end of the third switch, respectively; the first end of the second switch and the second end of the third switch are connected to the integrating subunit; the second end of the second switch is connected to a first power supply; the first ends of the three switches are connected to the first power supply; the first end of the fourth switch is connected to the sensing unit, the second end of the fourth switch is connected to the first power supply; the first end of the fifth switch is connected to the sensing unit, and the second end of the fifth switch is connected to the second power supply; the first and fifth switches have the same on-off state, the second, third, and fourth switches have the same on-off state, and the first and second switches have different on-off states; when the second switch is on, the power supply subunit provides a power supply voltage to the sensing unit via the first power supply; when the first switch is on, the power supply subunit provides a power supply voltage to the sensing unit via the second power supply and the digital-to-analog converter.

[0010] In one possible implementation, the identification unit further includes: a second capacitor; a first end of the second capacitor is respectively connected to the first end of the first switch and the first end of the second switch, and a second end of the second capacitor is respectively connected to the sensing unit and the second end of the third switch; the second capacitor is used to offset the basic capacitance in the first capacitor when the sensing unit generates an electrical signal, wherein the basic capacitance is the equivalent capacitance of the portion of the object to be identified that does not carry fingerprint information.

[0011] In one possible implementation, the at least one filter resistor includes at least one first resistor; the at least one first resistor is arranged between the sensing unit and the integrator unit, and when multiple first resistors are included between the sensing unit and the integrator unit, the multiple first resistors are arranged in series.

[0012] In one possible implementation, the identification unit includes at least two filter resistors, and the at least two filter resistors include a second resistor; a first end of the second resistor is connected to a second end of the third switch, and a second end of the second resistor is respectively connected to the integrator unit and the sensing unit.

[0013] In one possible implementation, the integrator subunit includes: an operational amplifier, a third capacitor, a sixth switch, a seventh switch, and an eighth switch; the first end of the sixth switch is respectively connected to the first end of the second switch, the second end of the third switch, and the sensing unit; the second end of the sixth switch is respectively connected to the negative input end of the operational amplifier and the first end of the third capacitor; the positive input end of the operational amplifier is connected to the second power supply; the output end of the operational amplifier is respectively connected to the first end of the seventh switch and the second end of the third capacitor; the second end of the seventh switch is electrically connected to the processing unit; the first end of the eighth switch is connected to the negative input end of the operational amplifier; and the second end of the eighth switch is connected to the output end of the operational amplifier; the sixth switch has the same on-off state as the first switch; when the sixth switch is on, the integrator subunit receives the electrical signal; when the seventh switch is on, the integrator subunit outputs the identification signal; and when the eighth switch is on, the integrator subunit is reset; wherein at least two of the sixth, seventh, and eighth switches are open.

[0014] In one possible implementation, the power supply unit further includes: a first buffer; the first buffer is arranged between the digital-to-analog converter and the second end of the first switch; the first buffer is used to reduce the internal resistance of the digital-to-analog converter and improve the driving capability of the digital-to-analog converter.

[0015] In one possible implementation, the integrator unit further includes: a second buffer; the second buffer is arranged between the second power supply and the positive input terminal of the operational amplifier; the second buffer is used to reduce the internal resistance of the second power supply and improve the driving capability of the second power supply.

[0016] In one possible implementation, the power supply unit further includes: a third resistor and a fourth capacitor; the second end of the third resistor is connected to the output end of the digital-to-analog converter, the first end of the third resistor is respectively connected to the first end of the fourth capacitor and the second end of the first switch, and the second end of the fourth capacitor is grounded; the third resistor and the fourth capacitor constitute a second filtering circuit to filter the power supply voltage output by the digital-to-analog converter.

[0017] In one possible implementation, the integrator unit further includes: a fourth resistor and a fifth capacitor; the first end of the fourth resistor is connected to the second power supply, the second end of the fourth resistor is respectively connected to the first end of the fifth capacitor and the positive input terminal of the operational amplifier, and the second end of the fifth capacitor is grounded; the fourth resistor and the fifth capacitor constitute a third filtering circuit to filter the supply voltage output by the second power supply to the operational amplifier.

[0018] According to a second aspect of an embodiment of the present application, an electronic device is provided, comprising: a processing unit and the fingerprint module as described in the first aspect, wherein the processing unit is configured to perform fingerprint recognition based on a recognition signal transmitted by the fingerprint module.

[0019] According to the fingerprint module provided in the embodiment of the present application, the fingerprint module includes a sensing unit and multiple identification units. The sensing unit can generate an electrical signal when the object to be identified is pressed on the identification area. The identification unit can convert the electrical signal into an identification signal and send it to the processing unit. The processing unit can perform fingerprint identification based on the identification signals sent by each identification unit. Since at least one filter resistor is provided in the identification unit, at least part of the filter resistor can form a first filter circuit with the sensing unit. Therefore, the electrical signal received by the identification unit is an electrical signal filtered by the first filter circuit, and the external signal interference coupled to the sensing unit by the object to be identified can be filtered out. The identification unit can generate an identification signal based on the filtered electrical signal, so that the external interference in the identification signal is less. Compared with the existing technology, the external interference in the fingerprint identification process can be reduced, the clarity of the fingerprint image can be improved, and the success rate of fingerprint identification can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0021] Figure 1 is a schematic diagram of a fingerprint module provided in an embodiment of the present application;

[0022] Figure 2 is a schematic diagram of a sensing unit provided in an embodiment of the present application;

[0023] Figure 3 is a schematic diagram of a power supply unit provided in an embodiment of the present application;

[0024] Figure 4 is a schematic diagram of an identification unit provided in an embodiment of the present application;

[0025] Figure 5 is a schematic diagram of an identification unit including a filter resistor provided in an embodiment of the present application;

[0026] Figure 6 is a schematic diagram of another identification unit including a filter resistor provided in an embodiment of the present application;

[0027] Figure 7 is a schematic diagram of an identification unit including a filter resistor provided by an embodiment of the present application;

[0028] Figure 8 is a schematic diagram of another identification unit including a filter resistor provided in an embodiment of the present application;

[0029] Figure 9 Schematic diagram of an integrator unit provided in an embodiment of the present application;

[0030] Figure 10 This is a schematic diagram of a switching timing provided by an embodiment of the present application;

[0031] Figure 11 is a schematic diagram of another switching timing provided by an embodiment of the present application;

[0032] Figure 12 is a schematic diagram of a power supply unit including a buffer provided in an embodiment of the present application;

[0033] Figure 13 is a schematic diagram of an integral subunit including a buffer provided in an embodiment of the present application;

[0034] Figure 14is a schematic diagram of a power supply subunit including a filter circuit provided in an embodiment of the present application;

[0035] Figure 15 is a schematic diagram of an integrator unit including a filter circuit provided in an embodiment of the present application;

[0036] Figure 16 This is a schematic diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field should fall within the scope of protection of the embodiments of the present application.

[0038] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. As used in this application and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0039] It should be understood that although the terms first, second, third, etc. may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0040] As mentioned above, with the development of smart devices, fingerprint recognition has become the mainstream security solution for smart devices. The side fingerprint solution has a different installation location from the traditional front and back fingerprint solution. The traditional front and back fingerprint solution needs to occupy the structural space on the front or back of the smart device, while the side fingerprint solution is set on the side of the middle frame of the smart device, avoiding the fingerprint module occupying the structural space on the front or back, and can meet the space requirements of the smart device. At present, the side fingerprint module adopts a capacitive fingerprint recognition solution. After the finger is pressed on the recognition area of ​​the fingerprint module, the fingerprint module performs fingerprint recognition based on the difference in equivalent capacitance between the valleys and ridges of the fingerprint. However, when the side fingerprint module is applied to an electronic device, some external signals are coupled to the fingerprint module through the finger. For example, when the electronic device is a mobile phone, because the fingerprint module is set close to the location of the mobile phone antenna, part of the antenna signal is coupled to the fingerprint module by the finger, which will cause the fingerprint module to be interfered with by external signals and the fingerprint recognition function is affected.

[0041] The present application provides a fingerprint module, which includes a sensing unit and multiple identification units. The sensing unit can generate an electrical signal when the object to be identified is pressed on the identification area. The identification unit can convert the electrical signal into an identification signal and send it to the processing unit. The processing unit can perform fingerprint identification based on the identification signals sent by each identification unit. Since at least one filter resistor is provided in the identification unit, at least part of the filter resistor can form a first filter circuit with the sensing unit. Therefore, the electrical signal received by the identification unit is an electrical signal filtered by the first filter circuit, and the external signal interference coupled to the sensing unit by the object to be identified can be filtered out. The identification unit can generate an identification signal based on the filtered electrical signal, so that the external signal interference in the identification signal is less. Compared with the existing technology, the external signal interference in the fingerprint identification process can be reduced, the clarity of the fingerprint image can be improved, and the success rate of fingerprint identification can be improved.

[0042] Figure 1 Schematic diagram of a fingerprint module provided in an embodiment of the present application, wherein the fingerprint module 100 is applied to electronic devices, such as Figure 1 As shown, the fingerprint module 100 includes a sensing unit 101 and multiple identification units 102, the multiple identification units 102 are electrically connected to different identification areas on the sensing unit 101, at least one filter resistor is electrically connected to the sensing unit 101, and at least some of the filter resistors and the sensing unit 101 form a first filter circuit.

[0043] The sensing unit 101 can generate an electrical signal when the object to be identified is pressed on the identification area. The identification unit 102 can convert the electrical signal filtered by the first filtering circuit into an identification signal, and send the identification signal to the processing unit of the electronic device, so that the processing unit performs fingerprint identification based on the identification signals sent by multiple identification units 102.

[0044] The sensing unit 101 includes multiple recognition areas, each of which can identify different locations on the object to be identified. Specifically, for example, taking a finger as the object to be identified, some recognition areas are located at locations corresponding to ridges in the fingerprint, while others are located at locations corresponding to valleys in the fingerprint. Due to the differences in ridges and valleys in the fingerprint, the signal strengths of the electrical signals generated by the recognition areas corresponding to ridges and valleys differ. Multiple recognition units 102 are electrically connected to different recognition areas on the sensing unit 101. Each recognition unit 102 is provided with at least one filter resistor, which is electrically connected to the sensing unit 101. At least some of the filter resistors can form a first filter circuit with the sensing unit 101. In one example, at least one filter resistor can form an RC low-pass filter with the sensing unit 101 to filter out high-frequency interference. After the sensing unit 101 generates an electrical signal, the signal is filtered by the first filter circuit. The recognition unit 102 converts the filtered signal into an identification signal and transmits the identification signal to the processing unit.

[0045] The processing unit may be a chip with processing functions in an electronic device, such as a processor of the electronic device or a fingerprint recognition chip of the electronic device, etc. The processing unit may identify the fingerprint image based on the recognition signal, and compare the identified fingerprint image with the registered fingerprint template to implement the fingerprint recognition function. Specifically, since the signal strengths of the electrical signals generated by the recognition areas corresponding to the ridges of the fingerprint and the recognition areas corresponding to the valleys of the fingerprint in the sensing unit 101 are different, each recognition unit 102 generates a recognition signal based on the signal strength of the received filtered electrical signal. Due to the different signal strengths of the electrical signals, the recognition signals generated by different recognition units 102 are different. The processing unit identifies the distribution of the ridges and valleys of the fingerprint based on the differences between the recognition signals, obtains a fingerprint image, and compares the fingerprint image with the fingerprint template to implement the fingerprint recognition function.

[0046] In an embodiment of the present application, the fingerprint module 100 includes a sensing unit 101 and multiple identification units 102. The sensing unit 101 can generate an electrical signal when the object to be identified is pressed on the identification area. The identification unit 102 can convert the electrical signal into an identification signal and send it to the processing unit. The processing unit can perform fingerprint identification based on the identification signals sent by each identification unit 102. Since at least one filter resistor is provided in the identification unit 102, at least part of the filter resistors can form a first filtering circuit with the sensing unit 101. Therefore, the electrical signal received by the identification unit 102 is an electrical signal filtered by the first filtering circuit, and the external signal interference coupled to the sensing unit 101 by the object to be identified can be filtered out. The identification unit 102 can generate an identification signal based on the filtered electrical signal, so that the external signal interference in the identification signal is less. Compared with the prior art, the external signal interference in the fingerprint recognition process can be reduced, the clarity of the fingerprint image can be improved, and the success rate of fingerprint recognition can be improved.

[0047] Figure 2 is a schematic diagram of a sensing unit provided in an embodiment of the present application, such as Figure 2 As shown, the sensing unit 101 includes a first electrode layer 1011 and a second electrode layer 1012, the first electrode layer 1011 and the second electrode layer 1012 are electrically connected to the identification unit 102 respectively, the identification area is located on the first electrode layer 1011, at least one filter resistor is electrically connected to the first electrode layer 1011, and the first electrode layer 1011 can form a first capacitance Cf with the object to be identified when the object to be identified is pressed on the identification area to generate an electrical signal according to the first capacitance Cf, and the second electrode layer 1012 can prevent parasitic capacitance from being generated between the first electrode layer 1011 and the identification unit 102.

[0048] The sensing unit 101 may include a first electrode layer 1011 and a second electrode layer 1012. The first electrode layer 1011 may include multiple identification areas. When the object to be identified is pressed on the identification area, a first capacitor Cf is formed between the first electrode layer 1011 and the object to be identified. The first capacitor Cf is an equivalent capacitor. Taking the object to be identified as a finger as an example, since there are ridges and valleys in the fingerprint of the finger, when the finger is pressed on the identification area, the distance between the ridge of the fingerprint of the finger and the first electrode layer 1011 is closer, and the distance between the valley of the fingerprint of the finger and the first electrode layer 1011 is farther. Therefore, the first capacitor Cf between the ridge of the fingerprint of the finger and the first electrode layer 1011 is greater than the first capacitor Cf between the valley of the fingerprint of the finger and the first electrode layer 1011, resulting in different signal strengths of the electrical signals generated by the identification area corresponding to the ridge of the fingerprint and the identification area corresponding to the valley of the fingerprint, and different identification areas generate electrical signals with different signal strengths.

[0049] The second electrode layer 1012 of the sensing unit 101 can form an equivalent capacitance with the first electrode layer 1011. This equivalent capacitance is a shielding capacitance Cp. This shielding capacitance Cp can prevent parasitic capacitance from being generated between the first electrode layer 1011 and the identification unit 102. For example, parasitic capacitance can be prevented between the first electrode layer 1011 and the metal traces of the identification unit 102. At least some of the at least one filter resistor can form a first filter circuit with the first capacitor Cf and the shielding capacitance Cp.

[0050] It should be noted that Figure 2 This is merely an example of a sensing unit 101 , and the specific configuration of the first electrode layer 1011 and the second electrode layer 1012 can be set as needed and is not limited here.

[0051] In the embodiment of the present application, the sensing unit 101 includes a first electrode layer 1011 and a second electrode layer 1012. The first electrode layer 1011 can generate a first capacitance Cf between the first electrode layer 1011 and the object to be identified, so as to generate an electrical signal according to the first capacitance Cf to realize the collection of fingerprint information. The second electrode layer 1012 can prevent the generation of parasitic capacitance between the first electrode layer 1011 and the identification unit 102. Since at least one filter resistor is electrically connected to the first electrode layer 1011, a first filter circuit can be formed through the filter resistor and the sensing unit 101 to filter the electrical signal generated by the first electrode layer 1011, which can reduce the signal strength of the interference signal in the electrical signal to increase the proportion of fingerprint information in the electrical signal, thereby improving the clarity of the identified fingerprint image and improving the success rate of fingerprint recognition.

[0052] In one possible implementation, the identification unit includes a power supply unit, an integration unit and at least one filter resistor. The power supply unit is electrically connected to the sensing unit, the sensing unit is electrically connected to the integration unit, and at least one filter resistor is electrically connected to the sensing unit, and at least part of the filter resistor is arranged between the sensing unit and the integration unit. The sensing unit and the filter resistor arranged between the sensing unit and the integration unit form a first filtering circuit. The power supply unit can provide a power supply voltage to the sensing unit so that when the object to be identified is pressed on the identification area, the sensing unit generates an electrical signal based on the power supply voltage, and the integration unit can generate an identification signal based on the electrical signal filtered by the first filtering circuit.

[0053] At least part of the at least one filter resistor is arranged between the sensing unit and the integral sub-unit, that is, the sensing unit and the integral sub-unit are electrically connected through the filter resistor, and the power supply unit can provide a power supply voltage to the sensing unit. When the object to be identified is pressed on the identification area, the sensing unit generates an electrical signal based on the power supply voltage and transmits the electrical signal to the integral sub-unit. A filter resistor is arranged between the integral sub-unit and the sensing unit. The equivalent capacitance between the sensing unit and the object to be identified, and the equivalent capacitance of the sensing unit and the filter resistor form a first filtering circuit. Therefore, during the transmission of the electrical signal, the electrical signal can be filtered by the first filtering circuit, and the integral sub-unit can generate an identification signal based on the electrical signal after filtering. In one example, the integral sub-unit can receive electrical signals after multiple filtering processes, integrate the multiple electrical signals separately, and obtain the identification signal based on the accumulation of the integration results.

[0054] In an embodiment of the present application, the identification unit includes a power supply sub-unit, an integral sub-unit and at least one filter resistor. The power supply sub-unit can provide a power supply voltage to the sensing unit. When the object to be identified is pressed on the identification area, the sensing unit generates an electrical signal based on the power supply voltage to realize the collection of fingerprint information. At least part of the filter resistor is arranged between the sensing unit and the integral sub-unit. Thus, a first filter circuit can be formed by the filter resistor and the sensing unit to filter the electrical signal generated by the sensing unit, which can increase the proportion of fingerprint information in the electrical signal. The integral sub-unit can generate an identification signal based on the filtered electrical signal to realize the fingerprint recognition function.

[0055] Figure 3 is a schematic diagram of a power supply unit provided in an embodiment of the present application, such as Figure 3 As shown, the power supply sub-unit 1021 includes a digital-to-analog converter DAC, a first switch K1, a second switch K2, a third switch K3, a fourth switch K4, and a fifth switch K5. The output end of the digital-to-analog converter DAC is connected to the second end of the first switch K1. The first end of the first switch K1 is respectively connected to the sensing unit 101, the first end of the second switch K2, and the second end of the third switch K3. The first end of the second switch K2 and the second end of the third switch K3 are connected to the integration sub-unit 1022. The second end of the second switch K2 is connected to the first power supply VDD. The first end of the third switch K3 is connected to the first power supply VDD. The first end of the fourth switch K4 is connected to the sensing unit 101. The second end of the fourth switch K4 is connected to the first power supply VDD. The first end of the fifth switch K5 is connected to the sensing unit 101. The second end of the fifth switch K5 is connected to the second power supply VCM.

[0056] The first switch K1 and the fifth switch K5 have the same on-off state, the second switch K2, the third switch K3, and the fourth switch K4 have the same on-off state, and the first switch K1 and the second switch K2 have different on-off states. When the second switch K2 is on, the power supply subunit 1021 provides a power supply voltage to the sensing unit 101 via the first power supply VDD. When the first switch K1 is on, the power supply subunit 1021 provides a power supply voltage to the sensing unit 101 via the second power supply VCM and the digital-to-analog converter DAC.

[0057] The following is a specific description using an example where the object to be identified is a finger.

[0058] When a finger is pressed on the recognition area, the second switch K2 is first controlled to be turned on. When the second switch K2 is turned on, the second switch K2, the third switch K3 and the fourth switch K4 are turned on at the same time. Since the finger can be equivalent to the ground line, the electronic unit 1021 charges the sensing unit 101 through the first power supply VDD, that is, the first capacitor Cf (the equivalent capacitance between the finger and the first electrode layer 1011) is charged through the first power supply VDD.

[0059] When the first switch K1 is turned on, the first switch K1 and the fifth switch K5 are turned on, and the second switch K2, the third switch K3, and the fourth switch K4 are turned off. The power supply unit provides a power supply voltage to the sensing unit 101 through the second power supply VCM and the digital-to-analog converter DAC. The sensing unit 101 generates an electrical signal based on the power supply voltage provided by the second power supply VCM and the digital-to-analog converter DAC and the charge charged into the first capacitor Cf during the charging phase, and transmits the electrical signal to the integrator unit 1022.

[0060] It should be noted that the filter resistor is not Figure 3 The specific setting position of the filter resistor is described in detail in subsequent embodiments.

[0061] In an embodiment of the present application, the power supply unit 1021 includes a digital-to-analog converter DAC, a first switch K1, a second switch K2, a third switch K3, a fourth switch K4 and a fifth switch K5. When the second switch K2, the third switch K3 and the fourth switch K4 are turned on at the same time, the power supply unit 1021 provides a power supply voltage to the sensing unit 101 through the first power supply VDD to charge the equivalent capacitance of the finger. When the first switch K1 and the fifth switch K5 are turned on, the power supply unit 1021 provides a power supply voltage to the sensing unit 101 through the second power supply VCM and the digital-to-analog converter DAC. The sensing unit 101 generates an electrical signal based on the charge charged in the first capacitor Cf, the second power supply VCM and the power supply voltage provided to the sensing unit 101 by the digital-to-analog converter DAC, thereby collecting fingerprint information of the object to be identified through the sensing unit 101.

[0062] Figure 4is a schematic diagram of an identification unit provided in an embodiment of the present application, such as Figure 4 As shown, the identification unit 102 further includes: a second capacitor Cc, wherein a first end of the second capacitor Cc is respectively connected to the first end of the first switch K1 and the first end of the second switch K2, and a second end of the second capacitor Cc is respectively connected to the sensing unit 101 and the second end of the third switch K3. The second capacitor Cc can offset the basic capacitance of the first capacitor Cf when the sensing unit 101 generates an electrical signal, wherein the basic capacitance is the equivalent capacitance of the portion of the object to be identified that does not carry fingerprint information.

[0063] The identification unit 102 also includes a second capacitor Cc, which is arranged between the first end of the second switch K2 and the sensing unit 101. When the object to be identified is pressed on the identification area, the first capacitor Cf (equivalent capacitor) between the object to be identified and the sensing unit 101 is composed of an information capacitor and a basic capacitor. The information capacitor is the equivalent capacitor corresponding to the fingerprint information on the object to be identified, and the basic capacitor is the equivalent capacitor of the non-fingerprint information part of the object to be identified. Taking a finger as an example, the equivalent capacitance of the finger fingerprint is the information capacitor, and the equivalent capacitance of the finger is the basic capacitance. The second capacitor Cc can offset the basic capacitance in the first capacitor Cf, so that the output result of the integrator unit 1022 is only the result corresponding to the information capacitor.

[0064] In the embodiment of the present application, the identification unit 102 also includes a second capacitor Cc. The second capacitor Cc can offset the equivalent capacitance of the part of the object to be identified that does not carry fingerprint information during the fingerprint identification process, so that when fingerprint identification is performed, identification is performed only based on the equivalent capacitance of the fingerprint information of the object to be identified. This can improve the dynamic range of the fingerprint information in the electrical signal and increase the proportion of fingerprint information in the electrical signal, thereby improving the clarity of the identified fingerprint image and improving the success rate of fingerprint identification.

[0065] In one possible implementation, the at least one filter resistor includes at least one first resistor, and the at least one first resistor is arranged between the sensing unit and the integrator unit. When multiple first resistors are included between the sensing unit and the integrator unit, the multiple first resistors are arranged in series.

[0066] Here are some examples to illustrate: Figure 5 is a schematic diagram of an identification unit including a filter resistor provided in an embodiment of the present application, such as Figure 5 As shown, when a first resistor R1 is included, Figure 5 (a) shows that the first resistor R1 is set between the first end of the second switch K2 and the sensing unit 101, and the first resistor R1 is located between the sensing unit 101 and the integrator unit 1022. Figure 5(b) shows that the first resistor R1 is set between the first end of the second switch K2 and the integration subunit 1022, and the first resistor R1 is located between the sensing unit 101 and the integration subunit 1022. Figure 5 (c) shows that the first resistor R1 is set between the first end of the second switch K2 and the integrator unit 1022, and the first resistor R1 is located between the second end of the third switch K3 and the integrator unit 1022, and the first resistor R1 is located between the sensing unit 101 and the integrator unit 1022.

[0067] Figure 6 is a schematic diagram of another identification unit including a filter resistor provided in an embodiment of the present application, such as Figure 6 As shown, when multiple first resistors R1 are included, the multiple first resistors R1 can be arranged in series, for example: Figure 6 (a), (b) and (c) show that two first resistors R1 are connected in series between the sensing unit 101 and the integrator unit 1022 .

[0068] Figure 7 This is a schematic diagram of an identification unit including a filter resistor provided by an embodiment of the present application, such as Figure 7 As shown, three first resistors R1 are connected in series between the sensing unit 101 and the integrator unit 1022 .

[0069] It should be understood that the number of filter resistors (first resistor R1) can be set as needed. Figure 5 、 Figure 6 and Figure 7 This should not limit the present application in any way. Specifically, Figure 5 、 Figure 6 and Figure 7 Each first resistor R1 can be formed by multiple resistors connected in series and set at a corresponding position of the first resistor R1. The specific number and position of the settings are not limited in the embodiment of the present application.

[0070] In an embodiment of the present application, at least one filter resistor includes at least one first resistor R1, and at least one first resistor R1 is arranged between the sensing unit 101 and the integrator unit 1022, so that a first filter circuit can be formed by the first resistor R1 and the sensing unit 101. The electrical signal generated by the sensing unit 101 is filtered and processed by the first filter circuit and then transmitted to the integrator unit 1022, thereby reducing external signal interference in the electrical signal and increasing the proportion of fingerprint information in the electrical signal, thereby improving the clarity of the fingerprint image and improving the success rate of fingerprint recognition.

[0071] Figure 8 This is a schematic diagram of another identification unit including a filter resistor provided in an embodiment of the present application, such as Figure 8As shown, the identification unit 102 includes at least two filter resistors, and the at least two filter resistors include a second resistor R2. The first end of the second resistor R2 is connected to the second end of the third switch K3, and the second end of the second resistor R2 is connected to the integrator unit 1022 and the sensing unit 101 respectively.

[0072] The identification unit 102 may include at least two filter resistors, the at least two filter resistors including a second resistor R2 and at least one first resistor R1 in the aforementioned embodiment, the second resistor R2 is arranged between the third switch K3 and the sensing unit 101, and the second resistor R2 is arranged between the third switch K3 and the integration subunit 1022. In one example, the second resistor R2 can form a filter circuit with the sensing unit 101, through which the supply voltage of the first power supply VDD can be filtered, and interference in the supply voltage can be filtered out. It should be noted that the at least one first resistor R1 can be arranged according to the aforementioned embodiment. Figure 5 、 Figure 6 and Figure 7 You can set it up in , which will not be described in detail here.

[0073] In an embodiment of the present application, the identification unit 102 includes at least two filter resistors, and the at least two filter resistors include a second resistor R2 and at least one first resistor R1. Thus, the second resistor R2 and the at least one first resistor R1 can form a filter circuit with the sensing unit 101, and the electrical signal output by the sensing unit 101 is filtered to reduce external signal interference in the electrical signal, and the proportion of fingerprint information in the electrical signal can be increased, thereby improving the clarity of the fingerprint image and improving the success rate of fingerprint recognition.

[0074] Figure 9 is a schematic diagram of an integral subunit provided in an embodiment of the present application, such as Figure 9As shown, the integrator subunit 1022 includes an operational amplifier D1, a third capacitor C3, a sixth switch K6, a seventh switch K7, and an eighth switch K8. The first end of the sixth switch K6 is connected to the first end of the second switch K2, the second end of the third switch K3, and the sensing unit 101, respectively. The second end of the sixth switch K6 is connected to the negative input end of the operational amplifier D1 and the first end of the third capacitor C3, respectively. The positive input end of the operational amplifier D1 is connected to the second power supply VCM. The output end of the operational amplifier D1 is connected to the first end of the seventh switch K7 and the second end of the third capacitor C3, respectively. The second end of the seventh switch K7 is electrically connected to the processing unit, the first end of the eighth switch K8 is connected to the negative input terminal of the operational amplifier D1, and the second end of the eighth switch K8 is connected to the output terminal of the operational amplifier D1. The sixth switch K6 has the same on-off state as the first switch K1. When the sixth switch K6 is turned on, the integrator subunit 1022 receives the electrical signal. When the seventh switch K7 is turned on, the integrator subunit 1022 outputs the identification signal. When the eighth switch K8 is turned on, the integrator subunit 1022 is reset. At least two of the sixth switch K6, the seventh switch K7, and the eighth switch K8 are open. For convenience of explanation, Figure 9 The setting of at least one filter resistor is not shown. The setting position of at least one filter resistor can refer to the scheme in the above embodiment. Specifically, the filter resistor can be set between the sixth switch K6 of the sensing unit 101 and the identification unit 102 with reference to the scheme in the above embodiment.

[0075] The following describes in detail the process of generating the identification signal by the integration sub-unit 1022 using an example.

[0076] Figure 10 This is a schematic diagram of a switching sequence provided by an embodiment of the present application, such as Figure 10 As shown, when a finger is pressed on the recognition area, the second switch K2 is first controlled to be turned on. When the second switch K2 is turned on, the second switch K2, the third switch K3 and the fourth switch K4 are turned on at the same time. Since the finger can be equivalent to the ground line, the electronic unit 1021 charges the sensing unit 101 through the first power supply VDD, that is, the first capacitor Cf (the equivalent capacitance between the finger and the sensing unit 101) is charged through the first power supply VDD.

[0077] When the first switch K1 is turned on, the first switch K1 and the fifth switch K5 are turned on, and the second switch K2, the third switch K3, and the fourth switch K4 are turned off. The power supply unit provides a power supply voltage to the sensing unit 101 through the second power supply VCM and the digital-to-analog converter DAC. The sensing unit 101 generates an electrical signal based on the second power supply VCM, the digital-to-analog converter DAC, and the charge charged into the first capacitor Cf during the charging phase, and transmits the electrical signal to the integrator unit 1022.

[0078] After receiving the electrical signal, the integration subunit 1022 records the charge in the electrical signal into the third capacitor C3. After N integrations, the seventh switch K7 is turned on and an identification signal is output based on the charge recorded in the third capacitor C3. It should be noted that the number of integrations can be set as needed. Each time the first switch K1 is turned on, an integration process is completed. When the number of times the first switch K1 is turned on reaches N times, the seventh switch K7 is turned on and an identification signal is output. After the identification signal is output, the eighth switch K8 is turned on. At this time, the integration subunit 1022 is reset to clear the charge stored in the third capacitor C3 to enter the next identification process. It should also be noted that if Figure 10 As shown, at least two of the sixth switch K6, the seventh switch K7 and the eighth switch K8 are disconnected. When the sixth switch K6 is turned on, the seventh switch K7 and the eighth switch K8 are disconnected. When the seventh switch K7 is turned on, the sixth switch K6 and the eighth switch K8 are disconnected. When the eighth switch K8 is turned on, the sixth switch K6 and the seventh switch K7 are disconnected.

[0079] Alternatively, as Figure 10 As shown, the distance between adjacent rising edges / falling edges of K2 is the charging period, and the distance between adjacent rising edges / falling edges of K1 is the integration period. The charging period is equal to the integration period, and the charging period / integration period is defined as T work , charging frequency / integration frequency is The charging cycle / integration period T can be adjusted work , so that the charging frequency / integral frequency f work Avoid high-frequency interference.

[0080] Optionally, the charging cycle / integration cycle can be randomized to reduce the impact of high-frequency interference peak power, for example: Figure 11 This is a schematic diagram of another switching sequence provided by an embodiment of the present application, such as Figure 11 As shown, the charging cycle / integration cycle, that is, the interval between adjacent rising edges / falling edges of K2 is the charging cycle, and the interval between adjacent rising edges / falling edges of K1 is the integration cycle. The charging cycle and the integration cycle are both random lengths.

[0081] In the embodiment of the present application, the integration sub-unit 1022 includes an operational amplifier D1, a third capacitor C3, a sixth switch K6, a seventh switch K7 and an eighth switch K8. When the sixth switch K6 is turned on, the operational amplifier D1 and the third capacitor C3 integrate the electrical signal. When the seventh switch K7 is turned on, the operational amplifier D1 outputs the charge stored in the third capacitor C3 to form an identification signal, thereby converting the electrical signal into an identification signal and realizing the signal integration process, so that the processing unit can identify the fingerprint image according to the identification signal, thereby realizing fingerprint recognition.

[0082] Figure 12is a schematic diagram of a power supply unit including a buffer provided in an embodiment of the present application, such as Figure 12 As shown, the power supply unit 1021 further includes a first buffer buffer1, which is arranged between the digital-to-analog converter DAC and the second end of the first switch K1. The first buffer buffer1 can reduce the internal resistance of the digital-to-analog converter DAC and improve the driving capability of the digital-to-analog converter DAC.

[0083] In an embodiment of the present application, the power supply unit 1021 further includes a first buffer buffer1, which is disposed between the digital-to-analog converter DAC and the second end of the first switch K1. The first buffer buffer1 can improve the driving capability of the digital-to-analog converter DAC, thereby providing a power supply voltage to the sensing unit 101 through the digital-to-analog converter DAC when the first switch K1 is turned on.

[0084] Figure 13 Schematic diagram of an integral subunit including a buffer provided in an embodiment of the present application, Figure 13 As shown, the integration subunit 1022 further includes a second buffer buffer2, which is arranged between the second power supply VCM and the positive input terminal of the operational amplifier D1. The second buffer buffer2 is used to reduce the internal resistance of the second power supply VCM and improve the driving capability of the second power supply VCM.

[0085] In the embodiment of the present application, the integrator unit 1022 further includes a second buffer buffer2, which is disposed between the second power supply VCM and the positive input terminal of the operational amplifier D1. The second buffer buffer2 can improve the driving capability of the second power supply VCM, so that the second power supply VCM can provide a power supply voltage to the integrator unit 1022 to obtain an identification signal.

[0086] Figure 14 is a schematic diagram of a power supply unit including a filter circuit provided in an embodiment of the present application, such as Figure 14 As shown, the power supply subunit 1021 further includes a third resistor R3 and a fourth capacitor C4. The second end of the third resistor R3 is connected to the output end of the digital-to-analog converter DAC, the first end of the third resistor R3 is connected to the first end of the fourth capacitor C4 and the second end of the first switch K1, respectively, and the second end of the fourth capacitor C4 is grounded. The third resistor R3 and the fourth capacitor C4 form a second filter circuit to filter the power supply voltage output by the digital-to-analog converter DAC.

[0087] It should be noted that when the power supply unit 1021 includes Figure 12In the case of the first buffer buffer1 shown, the third resistor R3 and the fourth capacitor C4 are arranged between the output terminal of the digital-to-analog converter DAC and the first buffer buffer1, that is, the second end of the third resistor R3 is connected to the output terminal of the digital-to-analog converter DAC, the first end of the third resistor R3 is connected to the first end of the fourth capacitor C4 and the input terminal of the first buffer buffer1, respectively, and the second end of the fourth capacitor C4 is grounded.

[0088] In an embodiment of the present application, the power supply unit 1021 further includes a third resistor R3 and a fourth capacitor C4. The third resistor R3 and the fourth capacitor C4 form a second filtering circuit, which can filter the power supply voltage output by the digital-to-analog converter DAC, thereby reducing external signal interference in the power supply voltage provided by the digital-to-analog converter DAC.

[0089] Figure 15 is a schematic diagram of an integrator unit including a filter circuit provided in an embodiment of the present application, such as Figure 15 As shown, the integrator sub-unit 1022 further includes a fourth resistor R4 and a fifth capacitor C5. The first end of the fourth resistor R4 is connected to the second power supply VCM, the second end of the fourth resistor R4 is connected to the first end of the fifth capacitor C5 and the positive input terminal of the operational amplifier D1, respectively, and the second end of the fifth capacitor C5 is grounded. The fourth resistor R4 and the fifth capacitor C5 form a third filtering circuit for filtering the supply voltage output from the second power supply VCM to the operational amplifier D1.

[0090] It should be noted that when the integrator unit 1022 includes Figure 13 In the second buffer buffer2 shown, the fourth resistor R4 and the fifth capacitor C5 are arranged between the second power supply VCM and the second buffer buffer2, that is, the first end of the fourth resistor R4 is connected to the second power supply VCM, the second end of the fourth resistor R4 is connected to the first end of the fifth capacitor C5 and the input end of the second buffer buffer2, respectively, and the second end of the fifth capacitor C5 is grounded.

[0091] In the embodiment of the present application, the integrator sub-unit 1022 further includes a fourth resistor R4 and a fifth capacitor C5. The fourth resistor R4 and the fifth capacitor C5 form a third filtering circuit, which can filter the supply voltage output by the second power supply VCM, thereby reducing external signal interference in the supply voltage provided by the second power supply VCM.

[0092] Figure 16 is a schematic diagram of an electronic device provided in an embodiment of the present application, such as Figure 16 As shown, the electronic device 200 includes a processing unit 201 and the fingerprint module 100 in any of the above embodiments. The processing unit 201 can perform fingerprint recognition based on the recognition signal transmitted by the fingerprint module 100.

[0093] In an embodiment of the present application, the processing unit 201 of the electronic device 200 can perform fingerprint recognition based on the recognition signal transmitted by the fingerprint module 100. Since at least one filter resistor is provided in the recognition unit in the fingerprint module 100, at least part of the filter resistor can form a first filter circuit with the sensing unit in the fingerprint module 100. Therefore, the recognition unit can generate a recognition signal based on the electrical signal after filtering, so that the fingerprint information in the recognition signal is less interfered with. The fingerprint image recognized by the processing unit 201 based on the recognition signal has less external interference, which can improve the clarity of the fingerprint image, thereby improving the accuracy of fingerprint recognition for users and improving the user's fingerprint recognition experience.

[0094] It should be pointed out that, according to the needs of implementation, the various components / steps described in the embodiments of the present application can be split into more components / steps, or two or more components / steps or partial operations of components / steps can be combined into new components / steps to achieve the purpose of the embodiments of the present application.

[0095] Those skilled in the art will appreciate that the units and method steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the embodiments of this application.

[0096] The above implementation methods are only used to illustrate the embodiments of the present application, and are not intended to limit the embodiments of the present application. Ordinary technicians in the relevant technical field can make various changes and modifications without departing from the spirit and scope of the embodiments of the present application. Therefore, all equivalent technical solutions also fall within the scope of the embodiments of the present application, and the scope of patent protection of the embodiments of the present application should be defined by the claims.

Claims

1. A fingerprint module, applied to electronic equipment, characterized in that: The fingerprint module includes: a sensing unit and a plurality of recognition units; The plurality of identification units are electrically connected to different identification areas on the sensing unit, respectively. The identification unit is provided with at least one filter resistor, the at least one filter resistor is electrically connected to the sensing unit, and at least part of the filter resistor and the sensing unit form a first filter circuit; The sensing unit is configured to generate an electrical signal when the object to be identified is pressed against the identification area; The identification unit is used to convert the electrical signal filtered by the first filtering circuit into an identification signal, and send the identification signal to the processing unit of the electronic device, so that the processing unit performs fingerprint identification based on the identification signals sent by the multiple identification units.

2. The fingerprint module according to claim 1, characterized in that: The sensing unit includes a first electrode layer and a second electrode layer; The first electrode layer and the second electrode layer are electrically connected to the identification unit respectively, the identification area is located on the first electrode layer, and the at least one filter resistor is electrically connected to the first electrode layer; The first electrode layer is configured to form a first capacitance with the object to be identified when the object to be identified is pressed against the identification area, so as to generate the electrical signal according to the first capacitance; The second electrode layer is used to prevent parasitic capacitance from being generated between the first electrode layer and the identification unit.

3. The fingerprint module according to claim 1, characterized in that: The identification unit includes a power supply subunit, an integration subunit and the at least one filter resistor; The power supply unit is electrically connected to the sensing unit, the sensing unit is electrically connected to the integrator unit, the at least one filter resistor is electrically connected to the sensing unit, and at least part of the filter resistor is arranged between the sensing unit and the integrator unit, and the sensing unit and the filter resistor arranged between the sensing unit and the integrator unit form the first filter circuit; The power supply unit is configured to provide a power supply voltage to the sensing unit, so that when the object to be identified is pressed against the identification area, the sensing unit generates the electrical signal based on the power supply voltage; The integrator unit is configured to generate the identification signal according to the electrical signal filtered by the first filtering circuit.

4. The fingerprint module according to claim 3, characterized in that: The power supply subunit includes a digital-to-analog converter, a first switch, a second switch, a third switch, a fourth switch and a fifth switch; The output end of the digital-to-analog converter is connected to the second end of the first switch, the first end of the first switch is respectively connected to the sensing unit, the first end of the second switch, and the second end of the third switch, the first end of the second switch and the second end of the third switch are connected to the integrator unit, the second end of the second switch is connected to the first power supply, the first ends of the three switches are connected to the first power supply, the first end of the fourth switch is connected to the sensing unit, the second end of the fourth switch is connected to the first power supply, the first end of the fifth switch is connected to the sensing unit, and the second end of the fifth switch is connected to the second power supply; The first switch and the fifth switch have the same on-off state, the second switch, the third switch and the fourth switch have the same on-off state, and the first switch and the second switch have different on-off states; When the second switch is turned on, the power supply unit provides a power supply voltage to the sensing unit through the first power supply; When the first switch is turned on, the power supply subunit provides a power supply voltage to the sensing unit through the second power supply and the digital-to-analog converter.

5. The fingerprint module according to claim 4, characterized in that: The identification unit further includes: a second capacitor; The first end of the second capacitor is connected to the first end of the first switch and the first end of the second switch respectively, and the second end of the second capacitor is connected to the sensing unit and the second end of the third switch respectively; The second capacitor is used to offset the basic capacitance of the first capacitor when the sensing unit generates an electrical signal, wherein the basic capacitance is the equivalent capacitance of the portion of the object to be identified that does not carry fingerprint information.

6. The fingerprint module according to claim 4, characterized in that: The at least one filter resistor includes at least one first resistor; The at least one first resistor is disposed between the sensing unit and the integrating subunit. When a plurality of first resistors are included between the sensing unit and the integrating subunit, the plurality of first resistors are connected in series.

7. The fingerprint module according to claim 6, characterized in that: The identification unit includes at least two filter resistors, and the at least two filter resistors include a second resistor; The first end of the second resistor is connected to the second end of the third switch, and the second end of the second resistor is connected to the integrator unit and the sensing unit respectively.

8. The fingerprint module according to claim 4, characterized in that: The integration subunit includes: an operational amplifier, a third capacitor, a sixth switch, a seventh switch and an eighth switch; The first end of the sixth switch is respectively connected to the first end of the second switch, the second end of the third switch, and the sensing unit; the second end of the sixth switch is respectively connected to the negative input end of the operational amplifier and the first end of the third capacitor; the positive input end of the operational amplifier is connected to the second power supply; the output end of the operational amplifier is respectively connected to the first end of the seventh switch and the second end of the third capacitor; the second end of the seventh switch is electrically connected to the processing unit; the first end of the eighth switch is connected to the negative input end of the operational amplifier, and the second end of the eighth switch is connected to the output end of the operational amplifier; The sixth switch has the same on-off state as the first switch. When the sixth switch is turned on, the integrator unit receives the electrical signal. When the seventh switch is turned on, the integrator unit outputs the identification signal. When the eighth switch is turned on, the integrator unit is reset. At least two of the sixth switch, the seventh switch, and the eighth switch are open.

9. The fingerprint module according to claim 4, characterized in that: The power supply unit further includes: a first buffer; The first buffer is provided between the digital-to-analog converter and the second end of the first switch; The first buffer is used to reduce the internal resistance of the digital-to-analog converter and improve the driving capability of the digital-to-analog converter.

10. The fingerprint module according to claim 8, characterized in that: The integration subunit further includes: a second buffer; The second buffer is arranged between the second power supply and the positive input terminal of the operational amplifier; The second buffer is used to reduce the internal resistance of the second power supply and improve the driving capability of the second power supply.

11. The fingerprint module according to claim 4, characterized in that: The power supply unit further includes: a third resistor and a fourth capacitor; The second end of the third resistor is connected to the output end of the digital-to-analog converter, the first end of the third resistor is connected to the first end of the fourth capacitor and the second end of the first switch respectively, and the second end of the fourth capacitor is grounded; The third resistor and the fourth capacitor form a second filter circuit to filter the power supply voltage output by the digital-to-analog converter.

12. The fingerprint module according to claim 8, characterized in that: The integrator unit further includes: a fourth resistor and a fifth capacitor; A first end of the fourth resistor is connected to the second power supply, a second end of the fourth resistor is connected to the first end of the fifth capacitor and the positive input terminal of the operational amplifier respectively, and a second end of the fifth capacitor is grounded; The fourth resistor and the fifth capacitor form a third filtering circuit for filtering the supply voltage output by the second power supply to the operational amplifier.

13. An electronic device, characterized in that: include: A processing unit and a fingerprint module according to any one of claims 1 to 12; The processing unit is used to perform fingerprint recognition according to the recognition signal transmitted by the fingerprint module.

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