Signal acquisition circuit, signal acquisition method, and electronic equipment

Abstract

The present disclosure provides a signal acquisition circuit, a signal acquisition method, and an electronic device. The signal acquisition circuit includes: a bias voltage line, a plurality of fingerprint pixel circuits, and a photocurrent acquisition module. Each fingerprint pixel circuit includes a photoelectric conversion unit, the photoelectric conversion unit is connected to the bias voltage line, and the photoelectric conversion unit outputs a photocurrent signal to the bias voltage line when illuminated. The photocurrent acquisition module is connected to the bias voltage line and is used to collect the photocurrent signal output by the bias voltage line of at least part of the photoelectric conversion unit. By multiplexing the fingerprint pixel circuit to detect the light intensity, the utilization rate of the fingerprint pixel circuit is improved, so that the electronic device including the signal acquisition circuit has a light intensity detection function and a fingerprint detection function, which is conducive to improving the market competitiveness of the electronic device.

Description

Technical Field

[0001] The present disclosure relates to the technical field of electronic equipment, and in particular to a signal acquisition circuit and a signal acquisition method, and electronic equipment. Background Art

[0002] With the rapid development of display technology, full-screen devices are becoming more and more popular among users. In order to meet the needs of users, major manufacturers have proposed a variety of solutions to increase the screen-to-body ratio. For example, the optical fingerprint detection module can be placed under the screen to realize the under-screen fingerprint detection technology. In addition, in order to meet the needs of large-area fingerprint recognition, the area of ​​the optical fingerprint detection module can be increased. However, at present, the optical fingerprint detection module is only used to detect fingerprints, and its utilization rate is low, which is not conducive to improving the market competitiveness of electronic equipment. Summary of the invention

[0003] The present disclosure provides an improved signal acquisition circuit and signal acquisition method, and electronic equipment.

[0004] One aspect of the present disclosure provides a signal acquisition circuit, the signal acquisition circuit comprising:

[0005] Bias voltage line;

[0006] a plurality of fingerprint pixel circuits, each of which comprises a photoelectric conversion unit, the photoelectric conversion unit is connected to the bias voltage line, and the photoelectric conversion unit outputs a photocurrent signal to the bias voltage line when illuminated; and

[0007] A photocurrent collection module is connected to the bias voltage line and is used to collect the photocurrent signal output by at least part of the photoelectric conversion unit via the bias voltage line.

[0008] Optionally, the photocurrent collection module includes: a power supply end, a feedback circuit, a voltage divider circuit and a voltage regulator;

[0009] The voltage regulator comprises a control terminal, a first connection terminal and a second connection terminal, the control terminal is connected to the feedback circuit, the first connection terminal is connected to the power supply terminal, the second connection terminal is connected to the voltage divider circuit, the voltage divider circuit is connected to the ground terminal and the feedback circuit, and a bias voltage point between the second connection terminal and the voltage divider circuit is connected to the bias voltage line;

[0010] The voltage divider circuit is used to divide the voltage at the bias voltage point to obtain a feedback voltage, and the feedback circuit is used to output a voltage adjustment signal to the voltage regulator based on the feedback voltage, so that the voltage regulator adjusts the voltage of the second connection terminal.

[0011] Optionally, the voltage-dividing circuit comprises a first voltage-dividing resistor and a second voltage-dividing resistor connected in series, the first voltage-dividing resistor is connected to the second connection end, and the second voltage-dividing resistor is connected to the ground end;

[0012] One end of the feedback circuit is connected between the first voltage-dividing resistor and the second voltage-dividing resistor.

[0013] Optionally, the photocurrent collection module also includes a first reference voltage terminal, the feedback circuit includes a first operational amplifier, the first operational amplifier includes a first input terminal, a second input terminal and a first output terminal, the first input terminal is connected to the first reference voltage terminal, the second input terminal is connected between the first voltage divider resistor and the second voltage divider resistor, and the first output terminal is connected to the control terminal.

[0014] Optionally, the photocurrent collection module further includes: a voltage detector, configured to detect the voltage of the second voltage-dividing resistor.

[0015] Optionally, the voltage regulator includes a transistor, the transistor includes a gate, the first connection terminal and the second connection terminal, and the gate is connected to the feedback circuit.

[0016] Optionally, the photocurrent collection module includes: a second operational amplifier, a feedback capacitor and a second reference voltage terminal;

[0017] The second operational amplifier includes a third input terminal, a fourth input terminal and a second output terminal, the third input terminal is connected to the second reference voltage terminal, the fourth input terminal is connected to the output terminal of the bias voltage line, one end of the feedback capacitor is connected to the fourth input terminal, and the other end is connected to the second output terminal.

[0018] Optionally, the bias voltage line includes a plurality of bias voltage branch lines and a bias voltage bus, the output end of each bias voltage branch line is connected to the input end of the bias voltage bus, the output end of the bias voltage bus is connected to the photocurrent collection module, and the plurality of fingerprint pixel circuits are arranged in a plurality of rows and columns;

[0019] The photoelectric conversion units of the fingerprint pixel circuits in each row are connected to the input end of one of the bias voltage branch lines, or the photoelectric conversion units of the fingerprint pixel circuits in each column are connected to the input end of one of the bias voltage branch lines.

[0020] Optionally, the bias voltage line includes a plurality of first bias voltage lines and a plurality of second bias voltage lines, at least part of the first bias voltage lines and at least part of the second bias voltage lines are arranged crosswise, the output end of the first bias voltage line is connected to the photocurrent collection module, and the plurality of fingerprint pixel circuits are arranged in a plurality of rows and columns;

[0021] The photoelectric conversion unit of each row of fingerprint pixel circuits in some rows is connected to one of the first bias voltage lines, and the photoelectric conversion unit of each row of fingerprint pixel circuits in other rows is connected to one of the second bias voltage lines, or the photoelectric conversion unit of each column of fingerprint pixel circuits in some columns is connected to one of the first bias voltage lines, and the photoelectric conversion unit of each column of fingerprint pixel circuits in other columns is connected to one of the second bias voltage lines.

[0022] Optionally, each of the fingerprint pixel circuits further includes a switch element connected to the photoelectric conversion unit;

[0023] The signal acquisition circuit also includes: a driving module connected to the switch element and a fingerprint signal reading module connected to the switch element. When detecting a fingerprint, the driving module is used to drive the switch element to conduct, so that the fingerprint signal reading module reads the fingerprint signal collected by the photoelectric conversion unit.

[0024] Another aspect of the present disclosure provides a signal acquisition method, which is used in a signal acquisition circuit, wherein the signal acquisition circuit includes: a bias voltage line, a plurality of fingerprint pixel circuits and a photocurrent acquisition module, each of the fingerprint pixel circuits includes a photoelectric conversion unit, and the photoelectric conversion unit and the photocurrent acquisition module are both connected to the bias voltage line. The signal acquisition method includes:

[0025] outputting a photocurrent signal to the bias voltage line through the photoelectric conversion unit when illuminated;

[0026] The photocurrent collection module collects at least part of the photocurrent signal output by the photoelectric conversion unit from the bias voltage line.

[0027] Optionally, the photocurrent collection module includes: a power supply end, a feedback circuit, a voltage divider circuit and a voltage regulator, the voltage regulator includes a control end, a first connection end and a second connection end, the control end is connected to the feedback circuit, the first connection end is connected to the power supply end, the second connection end is connected to the voltage divider circuit, the voltage divider circuit is connected to the ground end and the feedback circuit, and a bias voltage point between the second connection end and the voltage divider circuit is connected to the bias voltage line; the method further includes:

[0028] Dividing the voltage at the bias voltage point by the voltage divider circuit to obtain a feedback voltage;

[0029] The feedback circuit outputs a voltage regulating signal to the voltage regulating component based on the feedback voltage, so that the voltage regulating component regulates the voltage of the second connection terminal.

[0030] Optionally, the voltage divider circuit includes a first voltage divider resistor and a second voltage divider resistor connected in series, the first voltage divider resistor is connected to the second connection end, and the second voltage divider resistor is connected to the ground end; one end of the feedback circuit is connected between the first voltage divider resistor and the second voltage divider resistor; the photocurrent collection module further includes: a voltage detector; the method further includes:

[0031] The voltage of the second voltage dividing resistor is detected by the voltage detector.

[0032] Optionally, each of the fingerprint pixel circuits further includes a switch connected to the photoelectric conversion unit; the signal acquisition circuit further includes: a driving module connected to the switch and a fingerprint signal reading module connected to the switch; the method further includes:

[0033] When detecting a fingerprint, the driving module drives the switch element to conduct the fingerprint signal reading module and the photoelectric conversion unit, so that the fingerprint signal reading module reads the fingerprint signal collected by the photoelectric conversion unit.

[0034] Another aspect of the present disclosure provides an electronic device, which includes any one of the signal acquisition circuits mentioned above.

[0035] Optionally, the electronic device includes a display screen, and the signal acquisition circuit is arranged on the back side of the display screen.

[0036] The technical solution provided by the embodiments of the present disclosure has at least the following beneficial effects:

[0037] Based on the fact that both the photoelectric conversion unit and the photocurrent collection module are connected to the bias voltage line, the photoelectric conversion unit outputs a photocurrent signal to the bias voltage line when illuminated, and the photocurrent collection module collects the photocurrent signal output by the bias voltage line, and the light intensity can be determined according to the photocurrent signal. In this way, by multiplexing the fingerprint pixel circuit to detect the light intensity, the utilization rate of the fingerprint pixel circuit is improved, so that the electronic device including the signal collection circuit has the light intensity detection function and the fingerprint detection function, which is conducive to improving the market competitiveness of the electronic device. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 FIG. 1 is a schematic diagram of a partial structure of an electronic device according to an exemplary embodiment of the present disclosure;

[0039] Figure 2 Shown is a partial circuit diagram of a signal acquisition circuit according to an exemplary embodiment of the present disclosure;

[0040] Figure 3 FIG. 1 is a circuit diagram of a signal acquisition circuit according to an exemplary embodiment of the present disclosure;

[0041] Figure 4 FIG. 1 is an equivalent circuit diagram of a photodiode according to an exemplary embodiment of the present disclosure;

[0042] Figure 5 Shown is a circuit diagram of a photocurrent collection module connected to a photoelectric conversion unit according to an exemplary embodiment of the present disclosure;

[0043] Figure 6 Shown is a circuit diagram of a photocurrent collection module connected to a photoelectric conversion unit according to an exemplary embodiment of the present disclosure;

[0044] Figure 7 FIG. 1 is a schematic diagram of a local layout of a signal acquisition circuit according to an exemplary embodiment of the present disclosure;

[0045] Figure 8 FIG. 1 is a schematic diagram of a local layout of a signal acquisition circuit according to an exemplary embodiment of the present disclosure;

[0046] Fig. 9 FIG. 1 is a working timing diagram of a passive fingerprint pixel circuit according to an exemplary embodiment of the present disclosure;

[0047] Fig.10 FIG. 1 is a circuit diagram of an active fingerprint pixel circuit according to an exemplary embodiment of the present disclosure;

[0048] Fig.11 FIG. 1 is a working timing diagram of an active fingerprint pixel circuit according to an exemplary embodiment of the present disclosure;

[0049] Fig.12 Shown is a flow chart of a signal acquisition method according to an exemplary embodiment of the present disclosure;

[0050] Fig.13 Shown is a block diagram of an electronic device according to an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0051] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0052] The terms used in the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. Unless otherwise defined, the technical terms or scientific terms used in the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The words "first", "second" and similar words used in the present disclosure specification and claims do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, similar words such as "one" or "one" do not indicate a quantitative limit, but indicate that there is at least one. Unless otherwise specified, similar words such as "include" or "comprise" mean that the elements or objects appearing in front of "include" or "comprise" include the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects. Similar words such as "connect" or "connected" are not limited to physical or mechanical connections, and can include electrical connections, whether direct or indirect.

[0053] As used in this disclosure and the appended claims, the singular forms "a", "an", "said", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any or all possible combinations of one or more of the associated listed items.

[0054] In some embodiments, the optical fingerprint detection module can be placed under the screen to implement the under-screen fingerprint detection technology. By increasing the area of ​​the optical fingerprint detection module, the area of ​​fingerprint recognition can be increased to improve the user experience. However, this increases the cost of the optical fingerprint detection module, and thus increases the cost of the electronic device, and the optical fingerprint detection module is only used to detect fingerprints, and the utilization rate is low.

[0055] In order to improve the utilization rate of the optical fingerprint detection module and the market competitiveness of electronic devices, the present disclosure provides a signal acquisition circuit and a signal acquisition method, and an electronic device, which are described below in conjunction with the accompanying drawings:

[0056] Some embodiments of the present disclosure provide electronic devices with signal acquisition circuits, which can be used to acquire photocurrent signals, which are used to determine light intensity. The signal acquisition circuit can also be used to read fingerprint signals, which are used to detect fingerprints.

[0057] Figure 1 FIG. 1 is a partial structural diagram of an electronic device according to an exemplary embodiment of the present disclosure. Figure 1The electronic device includes a display screen 100, the display screen 100 includes a front side and a back side, the front side is used to be touched by a finger 101, and the signal acquisition circuit 200 is arranged on the back side of the display screen 100. In this way, the fingerprint detection technology under the screen can be realized, and the light intensity of the display screen 100 can be determined by using the photocurrent signal collected by the signal acquisition circuit 200.

[0058] Figure 2 FIG. 2 is a partial circuit diagram of a signal acquisition circuit 200 according to an exemplary embodiment of the present disclosure. Figure 3 FIG. 2 is a circuit diagram of a signal acquisition circuit 200 according to an exemplary embodiment of the present disclosure. Figure 2 and reference Figure 3 The signal acquisition circuit 200 includes: a bias voltage line 210, a plurality of fingerprint pixel circuits 220 and a photocurrent acquisition module 230.

[0059] Each fingerprint pixel circuit 220 includes a photoelectric conversion unit 221, which is connected to the bias voltage line 210. The photoelectric conversion unit 221 outputs a photocurrent signal to the bias voltage line 210 when illuminated. The photoelectric conversion unit 221 is used to convert the light signal into a photocurrent signal, and the light intensity can be determined according to the photocurrent signal. Exemplarily, the photoelectric conversion unit 221 includes a photosensitive diode or a phototransistor. The bias voltage line 210 is used to provide a bias voltage to the photoelectric conversion unit 221 to enable the photoelectric conversion unit 221 to work.

[0060] Figure 4 FIG. 1 is an equivalent circuit diagram of a photosensitive diode according to an exemplary embodiment of the present disclosure. Figure 4 , the photodiode PD can be equivalent to a parallel conductive element and capacitor C PD The bias voltage line 210 is connected to the cathode of the photodiode PD, and the anode voltage V N The voltage of the bias voltage line 210 is smaller than the negative electrode voltage (the voltage of the bias connection point Bias) supplied to the photodiode PD. The bias voltage line 210 is a fixed DC voltage, so that the photodiode PD works in the reverse bias region. Usually, when there is no light, the reverse resistance of the photodiode PD is large. When there is light, the reverse resistance of the photodiode PD decreases, and the photocurrent signal I generated by the photodiode PD is PD The photocurrent will flow from the positive electrode to the negative electrode of the photosensitive diode PD, that is, the photosensitive diode PD outputs a photocurrent signal I to the bias voltage line 210. PD The phototransistor also works in the reverse bias region. The working principle of the phototransistor is similar to that of the photodiode. When there is light, the photocurrent signal of the phototransistor is output to the bias voltage line, which will not be described in detail here.

[0061] The photocurrent collection module 230 is connected to the bias voltage line 210 and is used to collect the photocurrent signal output by at least part of the photoelectric conversion unit 221 via the bias voltage line 210 .

[0062] The signal acquisition circuit 200 provided in the embodiment of the present disclosure is based on that the photoelectric conversion unit 221 and the photocurrent acquisition module 230 are both connected to the bias voltage line 210. The photoelectric conversion unit 221 outputs a photocurrent signal to the bias voltage line 210 when illuminated, and the photocurrent acquisition module 230 acquires the photocurrent signal output by the bias voltage line 210, and the light intensity can be determined according to the photocurrent signal. In this way, by multiplexing the fingerprint pixel circuit 220 to detect the light intensity, the utilization rate of the fingerprint pixel circuit 220 is improved, so that the electronic device including the signal acquisition circuit 200 has a light intensity detection function and a fingerprint detection function, which is conducive to improving the market competitiveness of the electronic device. In addition, the original hardware for detecting the light intensity in the electronic device can be omitted, and the light intensity can be detected by multiplexing the fingerprint pixel circuit 220, which is conducive to reducing the cost of the electronic device.

[0063] Since the bias voltage line 210 needs to stably supply power to the photoelectric conversion unit 221 and the photocurrent signal needs to be detected through the bias voltage line 210, it is necessary to stabilize the voltage of the bias voltage line 210. Thus, the present disclosure provides the following two types of embodiments regarding the circuit structure of the photocurrent collection module 230:

[0064] Figure 5 FIG. 2 is a circuit diagram showing the connection between the photocurrent collection module 230 and the photoelectric conversion unit 221 according to an exemplary embodiment of the present disclosure. Figure 5 , the photocurrent collection module 230 includes: a power supply terminal VDD, a feedback circuit 231, a voltage divider circuit 232 and a voltage regulator 233; the voltage regulator 233 includes a control terminal, a first connection terminal and a second connection terminal, the control terminal is connected to the feedback circuit 231, the first connection terminal is connected to the power supply terminal VDD, the second connection terminal is connected to the voltage divider circuit 232, the voltage divider circuit 232 is connected to the ground terminal GND and the feedback circuit 231, and the bias voltage point a between the second connection terminal and the voltage divider circuit 232 is connected to the bias voltage line 210. The voltage divider circuit 232 is used to divide the voltage of the bias voltage point a to obtain a feedback voltage, and the feedback circuit 231 is used to output a voltage regulation signal to the voltage regulator 233 based on the feedback voltage, so that the voltage regulator 233 adjusts the voltage of the second connection terminal to stabilize the voltage of the bias voltage point a, which is conducive to the bias voltage line 210 to provide a stable bias voltage to the photoelectric conversion unit 221, and stably collect the photocurrent signal through the bias voltage line 210. The photocurrent collection module 230 has a good voltage stabilization effect and can collect photocurrent signals output by a large number of photoelectric conversion units 221 .

[0065] In some embodiments, continue to refer to Figure 5 , the voltage divider circuit 232 includes a first voltage divider resistor R1 and a second voltage divider resistor R2 connected in series, the first voltage divider resistor R1 is connected to the second connection end, and the second voltage divider resistor R2 is connected to the ground end GND; one end of the feedback circuit 231 is connected between the first voltage divider resistor R1 and the second voltage divider resistor R2. In this way, the feedback voltage obtained by dividing the voltage at the bias voltage point a by the voltage divider circuit 232 is Va*R1 / (R1+R2).

[0066] In some embodiments, continue to refer to Figure 5 The photocurrent collection module 230 also includes a first reference voltage terminal V REF The feedback circuit 231 includes a first operational amplifier A1, which includes a first input terminal, a second input terminal and a first output terminal. The first input terminal is connected to a first reference voltage terminal V REF The first operational amplifier A1 is connected to the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2, and the first output terminal is connected to the control terminal of the voltage regulator 233. The second input terminal of the first operational amplifier A1 receives the feedback voltage obtained by the voltage-dividing circuit 232 dividing the voltage of the bias voltage point a, and the first input terminal receives the first reference voltage. The first operational amplifier A1 outputs a voltage adjustment signal to the control terminal of the voltage regulator 233 based on the feedback voltage and the first reference voltage to control the voltage regulator 233 to adjust the voltage of the bias voltage point a. Exemplarily, the first input terminal is a negative input terminal, and the second input terminal is a positive input terminal.

[0067] In some embodiments, the voltage regulator 233 includes a transistor, the transistor includes a gate, a first connection terminal and a second connection terminal, and the gate is connected to the feedback circuit 231. Exemplarily, the transistor is a P-type transistor, the control terminal is the gate, the first connection terminal is the source, the source is connected to the power supply terminal VDD, the second terminal is the drain, and the drain is connected to the voltage divider circuit 232. The transistor adjusts the voltage drop based on the voltage adjustment signal fed back by the feedback circuit 231 to stabilize the voltage of the bias voltage point a.

[0068] Exemplarily, the first input terminal of the first operational amplifier A1 is a negative input terminal, the second input terminal is a positive input terminal, the voltage adjustment component 233 is a P-type transistor, and the voltage divider circuit 232 includes a first voltage divider resistor R1 and a second voltage divider resistor R2. When the voltage at the bias voltage point a increases, the voltage divided by the first voltage divider resistor R1 at the bias voltage point a increases, the first operational amplifier A1 obtains an increased feedback voltage, and the first operational amplifier A1 outputs a voltage adjustment signal to the transistor, so that the voltage of the gate increases and the voltage of the drain decreases, thereby stabilizing the voltage at the bias voltage point a. Correspondingly, when the voltage at the bias voltage point a decreases, the voltage divided by the first voltage divider resistor R1 at the bias voltage point a decreases, the first operational amplifier A1 obtains a decreased feedback voltage, and the first operational amplifier A1 outputs a voltage adjustment signal to the transistor, so that the voltage of the gate decreases and the voltage of the drain increases, thereby stabilizing the voltage at the bias voltage point a.

[0069] In some embodiments, continue to refer to Figure 5 , the photocurrent collection module 230 also includes: a voltage detector 234, which is used to detect the voltage of the second voltage-dividing resistor R2. Exemplarily, the voltage of the second voltage-dividing resistor R2 is detected twice by the voltage detector 234, and then the voltage difference can be obtained by other processing modules, and the change amount of the photocurrent signal is determined according to the voltage difference, and then the light intensity is determined according to the change amount of the photocurrent signal. Exemplarily, the voltage detector 234 can detect the voltage of the upper part of the second voltage-dividing resistor R2.

[0070] Figure 6 FIG. 2 is a circuit diagram showing the connection between the photocurrent collection module 230 and the photoelectric conversion unit 221 according to an exemplary embodiment of the present disclosure. Figure 6 The photocurrent collection module 230 includes: a second operational amplifier A2, a feedback capacitor C F The second operational amplifier A2 includes a third input terminal, a fourth input terminal and a second output terminal, the third input terminal is connected to the second reference voltage terminal V2, the fourth input terminal is connected to the output terminal of the bias voltage line 210, and the feedback capacitor C F One end of is connected to the fourth input terminal, and the other end is connected to the second output terminal. F The voltage signal output by the second operational amplifier A2 can be fed back to the bias voltage line 210, and can also stabilize the voltage of the bias voltage line 210. The photocurrent collection module 230 has a simple structure and can be used to collect photocurrent signals output by a relatively small number of photoelectric conversion units 221.

[0071] Figure 7 FIG. 2 is a schematic diagram of a local layout of a signal acquisition circuit 200 according to an exemplary embodiment of the present disclosure. Figure 7, the bias voltage line 210 includes a plurality of bias voltage branches 211 and a bias voltage bus 212, the output end of each bias voltage branch 211 is connected to the input end of the bias voltage bus 212, the output end of the bias voltage bus 212 is connected to the photocurrent acquisition module 230, and the plurality of fingerprint pixel circuits 220 are arranged in a plurality of rows and columns; the photoelectric conversion unit 221 of each row of fingerprint pixel circuits 220 is connected to the input end of a bias voltage branch 211, or the photoelectric conversion unit 221 of each column of fingerprint pixel circuits 220 is connected to the input end of a bias voltage branch 211. It can be understood that the photoelectric conversion units 221 corresponding to all fingerprint pixel circuits 220 are connected to the bias voltage bus 212, so that the photocurrent signal obtained through the bias voltage bus 212 is the sum of the photocurrent signals output by all the photocurrent conversion units 221, so that, without separately setting up other additional photocurrent signal summing circuits, the photocurrent signal obtained by the photocurrent acquisition module 230 can determine the light intensity of the display screen 100. By detecting the light intensity of the entire display screen, compared with specially setting up a light intensity detection module to detect the local light intensity of the display screen, it is beneficial to improve the accuracy of detecting the light intensity.

[0072] Figure 8 FIG. 2 is a schematic diagram of a local layout of a signal acquisition circuit 200 according to an exemplary embodiment of the present disclosure. Figure 8The bias voltage line 210 includes a plurality of first bias voltage lines 213 and a plurality of second bias voltage lines 214, at least part of the first bias voltage lines 213 and at least part of the second bias voltage lines 214 are arranged crosswise, the output end of the first bias voltage line 213 is connected to the photocurrent collection module 230, and the plurality of fingerprint pixel circuits 220 are arranged in a plurality of rows and columns. The photoelectric conversion unit 221 of each row of fingerprint pixel circuits 220 in some rows is connected to a first bias voltage line 213, and the photoelectric conversion unit 221 of each row of fingerprint pixel circuits 220 in other rows is connected to a second bias voltage line 214, or the photoelectric conversion unit 221 of each column of fingerprint pixel circuits 220 in some columns is connected to a first bias voltage line 213, and the photoelectric conversion unit 221 of each column of fingerprint pixel circuits 220 in other columns is connected to a second bias voltage line 214. It can be understood that the first bias voltage line 213 and the second bias voltage line 214 are alternately arranged, or some row areas are provided with multiple first bias voltage lines 213, and some row areas are provided with multiple second bias voltage lines 214. The arrangement of the columns is similar to that of the rows, and will not be repeated here. In this way, the photocurrent acquisition module 230 collects the photocurrent signals output by the photoelectric conversion units 221 of some rows or columns of the fingerprint pixel circuits 220 through the first bias voltage line 213, rather than collecting the photocurrent signals output by all the photoelectric conversion units 221, which reduces the requirements on the driving capability of the signal acquisition circuit 200, and because the first bias voltage line 213 and the second bias voltage line 214 intersect, this can also determine the overall brightness of the display screen.

[0073] In some embodiments, continue to refer to Figure 3 , each fingerprint pixel circuit 220 further includes a switch 222 connected to the photoelectric conversion unit 221; the signal acquisition circuit 200 further includes: a driving module 240 connected to the switch 222 and a fingerprint signal reading module 250 connected to the switch 222. When detecting a fingerprint, the driving module 240 is used to drive the switch 222 to conduct, so that the fingerprint signal reading module 250 reads the fingerprint signal collected by the photoelectric conversion unit 221. Usually, a plurality of fingerprint pixel circuits 220 are arranged in multiple rows and columns, and the driving module 240 drives the switch 222 of each row to conduct in sequence, so that the fingerprint signal reading module 250 reads the fingerprint signal collected by each row of fingerprint pixel circuits 220 in sequence.

[0074] Exemplarily, the fingerprint signal reading module 250 can be integrated with the photocurrent collection module 230. Exemplarily, the switch element 222 can be a TFT (Thin Film Transistor), and the fingerprint pixel circuit 220 can include an active fingerprint pixel circuit or a passive fingerprint pixel circuit. The working principles of the two fingerprint pixel circuits 220 are described below in conjunction with the accompanying drawings:

[0075] Fig. 9 FIG. 2 is a working timing diagram of a passive fingerprint pixel circuit 220 according to an exemplary embodiment of the present disclosure. The fingerprint pixel circuit 220 is a passive fingerprint pixel circuit 220. Figure 2 and Figure 3 Each fingerprint pixel circuit 220 includes: a first photosensitive diode PD1 and a first selection transistor SEL1 connected to the first photosensitive diode PD1, and the first selection transistor SEL1 is a switch element 222. When the first selection transistor SEL1 is driven to turn on by the driving module 240, the fingerprint signal reading module 250 can read the first voltage signal of the first photosensitive diode PD1. Fig. 9 , before time t1, the reset unit RST1 is reset, the first selection transistor SEL1 is driven to turn on by the driving module 240, and the fingerprint signal reading module 250 reads the voltage signal of the first photodiode PD1 at time t1. Then the driving module 240 drives the first selection transistor SEL1 to turn off, and the first photodiode PD1 accumulates the light signal under the exposure condition and converts it into a photocurrent signal, and the photocurrent signal can flow to the bias voltage line 210. Before time t2, the first selection transistor SEL1 is driven to turn on by the driving module 240, and the fingerprint signal reading module 250 reads the second voltage signal of the first photodiode PD1 at time t2, and determines the fingerprint signal based on the difference between the first voltage signal and the second voltage signal.

[0076] Fig.10 FIG. 2 is a circuit diagram of an active fingerprint pixel circuit 220 according to an exemplary embodiment of the present disclosure. Fig.11 FIG. 2 is a timing diagram of an active fingerprint pixel circuit 220 according to an exemplary embodiment of the present disclosure. The fingerprint pixel circuit 220 is an active fingerprint pixel circuit. Fig.10 Each fingerprint pixel circuit 220 includes: a second photosensitive diode PD2, a reset transistor RST2, a source follower transistor SF, and a second selection transistor SEL2. The second photosensitive diode PD2 is connected to the reset transistor RST2, one end of the source follower transistor SF is connected between the reset transistor RST2 and the second photosensitive diode PD2, and the other end is connected to the second selection transistor SEL2. Fig.10 and Fig.11Before time t3, the driving module 240 controls the reset transistor RST2 to reset, and controls the second selection transistor SEL2 to turn on, so that IBias at the output end of the fingerprint pixel circuit establishes a voltage through the second selection transistor SEL2, so that the OUT point reflects the voltage of the P point. At time t3, the third voltage signal collected by the fingerprint pixel circuit 220 is read by the fingerprint signal reading module 250. Then the driving module 240 controls the second selection transistor SEL2 to turn off, so that the second photosensitive diode PD2 is exposed. Before time t4, the second selection transistor SEL2 is driven to turn on by the driving module 240, so that IBias at the output end of the fingerprint pixel circuit is established again through the second selection transistor SEL2, so that the OUT point reflects the voltage of the P point. At time t4, the fourth voltage signal collected by the fingerprint pixel circuit 220 is read by the fingerprint signal reading module 250, and the difference between the third voltage signal and the fourth voltage signal is the fingerprint signal. The working principles of other row fingerprint pixel circuits are similar and will not be described in detail here.

[0077] Fig.12 The flowchart of the signal acquisition method according to an exemplary embodiment of the present disclosure is shown. The signal acquisition method provided by some embodiments of the present disclosure is used in a signal acquisition circuit, which includes: a bias voltage line, multiple fingerprint pixel circuits and a photocurrent acquisition module, each fingerprint pixel circuit includes a photoelectric conversion unit, and the photoelectric conversion unit and the photocurrent acquisition module are both connected to the bias voltage line. Fig.12 , the signal acquisition method includes:

[0078] Step 121: Outputting a photocurrent signal to the bias voltage line through the photoelectric conversion unit when illuminated. The photoelectric conversion unit generates a photocurrent signal when illuminated, and since the voltage of the bias voltage line is relatively small, the photocurrent signal can be outputted from the photoelectric conversion unit to the bias voltage line.

[0079] Step 122: Collect photocurrent signals outputted from at least some of the photoelectric conversion units by the bias voltage line through a photocurrent collection module. Exemplarily, the photocurrent collection module can collect photocurrent signals outputted from all photoelectric conversion units or from some photoelectric conversion units.

[0080] In some embodiments, the photocurrent collection module includes: a power supply end, a feedback circuit, a voltage divider circuit and a voltage regulator, the voltage regulator includes a control end, a first connection end and a second connection end, the control end is connected to the feedback circuit, the first connection end is connected to the power supply end, the second connection end is connected to the voltage divider circuit, the voltage divider circuit is connected to the ground end and the feedback circuit, and the bias voltage point between the second connection end and the voltage divider circuit is connected to the bias voltage line. The signal collection method provided in some embodiments of the present disclosure also includes: dividing the voltage of the bias voltage point by the voltage divider circuit to obtain a feedback voltage; outputting a voltage regulation signal to the voltage regulator based on the feedback voltage by the feedback circuit, so that the voltage regulator adjusts the voltage of the second connection end.

[0081] In some embodiments, the voltage divider circuit includes a first voltage divider resistor and a second voltage divider resistor connected in series, the first voltage divider resistor is connected to the second connection terminal, and the second voltage divider resistor is connected to the ground terminal; one end of the feedback circuit is connected between the first voltage divider resistor and the second voltage divider resistor; the photocurrent acquisition module also includes: a voltage detector; the signal acquisition method provided in some embodiments of the present disclosure also includes: detecting the voltage of the second voltage divider resistor by the voltage detector. Exemplarily, the voltage of the second voltage divider resistor is detected twice by the voltage detector, and then the voltage difference is obtained according to the voltages detected twice by other processing modules, and the change amount of the photocurrent signal is determined according to the voltage difference, and then the light intensity is determined according to the change amount of the photocurrent signal.

[0082] In some embodiments, each fingerprint pixel circuit also includes a switch element connected to the photoelectric conversion unit; the signal acquisition circuit also includes: a driving module connected to the switch element and a fingerprint signal reading module connected to the switch element; the signal acquisition method provided in some embodiments of the present disclosure also includes: when detecting a fingerprint, the switch element is driven by the driving module to turn on the fingerprint signal reading module and the photoelectric conversion unit, so that the fingerprint signal reading module reads the fingerprint signal collected by the photoelectric conversion unit.

[0083] For the signal acquisition method provided in the embodiment of the present disclosure, reference may be made to the relevant description of the signal acquisition circuit, which will not be repeated here.

[0084] The signal acquisition method provided by the embodiment of the present disclosure outputs a photocurrent signal to the bias voltage line when illuminated by light through the photoelectric conversion unit, and collects the photocurrent signal output by the bias voltage line of at least part of the photoelectric conversion unit through the photocurrent acquisition module, and the light intensity can be determined according to the photocurrent signal. In this way, by multiplexing the photoelectric conversion unit of the fingerprint pixel circuit to detect the light intensity, the utilization rate of the fingerprint pixel circuit is improved, and the electronic device including the signal acquisition circuit is endowed with the light intensity detection function and the fingerprint detection function, which is conducive to improving the market competitiveness of the electronic device. In addition, the original hardware for detecting the light intensity in the electronic device can be omitted, and the fingerprint pixel circuit is multiplexed to detect the light intensity, which is also conducive to reducing the cost of the electronic device.

[0085] Fig.13 The block diagram of an electronic device according to an exemplary embodiment of the present disclosure is shown. For example, the electronic device 1300 may be a smart phone, a computer, a digital broadcast terminal, a tablet device, a medical device, a fitness device, a personal digital assistant, etc., which includes a transmitting coil, a first magnetic sensor, and a second magnetic sensor in a device for adjusting earphone audio parameters.

[0086] refer to Fig.13 , the electronic device 1300 may include one or more of the following components: a processing component 1302 , a memory 1304 , a power component 1306 , a multimedia component 1308 , an audio component 1313 , an input / output (I / O) interface 1312 , a sensor component 1314 , and a communication component 1316 .

[0087] The processing component 1302 generally controls the overall operation of the electronic device 1300, such as operations associated with display, phone calls, data communications, camera operations, and recording operations. The processing component 1302 may include one or more processors 1320 to execute instructions. In addition, the processing component 1302 may include one or more modules to facilitate interaction between the processing component 1302 and other components. For example, the processing component 1302 may include a multimedia module to facilitate interaction between the multimedia component 1308 and the processing component 1302.

[0088] The memory 1304 is configured to store various types of data to support operations on the electronic device 1300. Examples of such data include instructions for any application or method operating on the electronic device 1300, contact data, phone book data, messages, pictures, videos, etc. The memory 1304 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk.

[0089] The power supply component 1306 provides power to the various components of the electronic device 1300. The power supply component 1306 may include a power management system, one or more power supplies, and other components associated with generating, managing, and distributing power to the electronic device 1300.

[0090] The multimedia component 1308 includes a screen that provides an output interface between the electronic device 1300 and the target object. In some embodiments, the screen may include a liquid crystal display (LCD) and a touch panel (TP). If the screen includes a touch panel, the screen may be implemented as a touch screen to receive input signals from the target object. The touch panel includes one or more touch sensors to sense touch, slide, and gestures on the touch panel. The touch sensor may not only sense the boundaries of a touch or slide action, but also detect the duration and pressure associated with the touch or slide operation.

[0091] The audio component 1313 is configured to output and / or input audio signals. For example, the audio component 1313 includes a microphone (MIC), and when the electronic device 1300 is in an operation mode, such as a call mode, a recording mode, and a voice recognition mode, the microphone is configured to receive an external audio signal. The received audio signal can be further stored in the memory 1304 or sent via the communication component 1316. In some embodiments, the audio component 1310 also includes a speaker for outputting audio signals.

[0092] The I / O interface 1312 provides an interface between the processing component 1302 and a peripheral interface module, which may be a keyboard, a click wheel, a button, etc.

[0093] The sensor assembly 1314 includes one or more sensors for providing various aspects of status assessment for the electronic device 1300. For example, the sensor assembly 1314 can detect the open / closed state of the electronic device 1300, the relative positioning of components, such as the display screen and keypad of the electronic device 1300, and the sensor assembly 1314 can also detect the position change of the electronic device 1300 or a component, the presence or absence of contact between the target object and the electronic device 1300, the orientation or acceleration / deceleration of the electronic device 1300, and the temperature change of the electronic device 1300.

[0094] The communication component 1316 is configured to facilitate wired or wireless communication between the electronic device 1300 and other devices. The electronic device 1300 can access a wireless network based on a communication standard, such as WiFi, 2G or 3G, or a combination thereof. In an exemplary embodiment, the communication component 1316 receives a broadcast signal or broadcast-related information from an external broadcast management system via a broadcast channel. In an exemplary embodiment, the communication component 1316 also includes a near field communication (NFC) module to facilitate short-range communication. For example, the NFC module can be implemented based on radio frequency identification (RFID) technology, infrared data association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology and other technologies.

[0095] In an exemplary embodiment, the electronic device 1300 may be implemented by one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components.

[0096] In an exemplary embodiment, a computer-readable storage medium is also provided, on which a program is stored, and when the program is executed by the processor 1320, any of the signal acquisition methods mentioned above is implemented. The readable storage medium may be a ROM, a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc.

[0097] As for the method embodiment, since it basically corresponds to the device embodiment, the relevant parts can be referred to the partial description of the device embodiment. The method embodiment and the device embodiment complement each other.

[0098] The above-mentioned various embodiments of the present disclosure may complement each other if no conflict occurs.

[0099] The above description is only a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the scope of protection of the present disclosure.

Claims

1. A signal acquisition circuit, characterized in that: The signal acquisition circuit comprises: Bias voltage line; a plurality of fingerprint pixel circuits, each of which comprises a photoelectric conversion unit, the photoelectric conversion unit is connected to the bias voltage line, and the photoelectric conversion unit outputs a photocurrent signal to the bias voltage line when illuminated; and a photocurrent collection module, connected to the bias voltage line, for collecting the photocurrent signal output by at least part of the photoelectric conversion unit from the bias voltage line, and determining the light intensity according to the photocurrent signal; The bias voltage line is used to provide a bias voltage for the photoelectric conversion unit to enable the photoelectric conversion unit to work; Each of the fingerprint pixel circuits further includes a switch element connected to the photoelectric conversion unit; The signal acquisition circuit also includes: a driving module connected to the switch element and a fingerprint signal reading module connected to the switch element. When detecting a fingerprint, the driving module is used to drive the switch element to conduct, so that the fingerprint signal reading module reads the fingerprint signal collected by the photoelectric conversion unit.

2. The signal acquisition circuit according to claim 1, characterized in that: The photocurrent collection module includes: a power supply end, a feedback circuit, a voltage divider circuit and a voltage regulator; The voltage regulator comprises a control terminal, a first connection terminal and a second connection terminal, the control terminal is connected to the feedback circuit, the first connection terminal is connected to the power supply terminal, the second connection terminal is connected to the voltage divider circuit, the voltage divider circuit is connected to the ground terminal and the feedback circuit, and the bias voltage point between the second connection terminal and the voltage divider circuit is connected to the bias voltage line; The voltage divider circuit is used to divide the voltage at the bias voltage point to obtain a feedback voltage, and the feedback circuit is used to output a voltage adjustment signal to the voltage regulator based on the feedback voltage, so that the voltage regulator adjusts the voltage of the second connection terminal.

3. The signal acquisition circuit according to claim 2, characterized in that: The voltage-dividing circuit comprises a first voltage-dividing resistor and a second voltage-dividing resistor connected in series, the first voltage-dividing resistor is connected to the second connection end, and the second voltage-dividing resistor is connected to the ground end; One end of the feedback circuit is connected between the first voltage-dividing resistor and the second voltage-dividing resistor.

4. The signal acquisition circuit according to claim 3, characterized in that: The photocurrent collection module also includes a first reference voltage terminal, the feedback circuit includes a first operational amplifier, the first operational amplifier includes a first input terminal, a second input terminal and a first output terminal, the first input terminal is connected to the first reference voltage terminal, the second input terminal is connected between the first voltage dividing resistor and the second voltage dividing resistor, and the first output terminal is connected to the control terminal.

5. The signal acquisition circuit according to claim 3, characterized in that: The photocurrent collection module further includes: a voltage detector, which is used to detect the voltage of the second voltage-dividing resistor.

6. The signal acquisition circuit according to claim 2, characterized in that: The voltage regulator includes a transistor, the transistor includes a gate, the first connection terminal and the second connection terminal, and the gate is connected to the feedback circuit.

7. The signal acquisition circuit according to claim 1, characterized in that: The photocurrent collection module includes: a second operational amplifier, a feedback capacitor and a second reference voltage terminal; The second operational amplifier includes a third input terminal, a fourth input terminal and a second output terminal, the third input terminal is connected to the second reference voltage terminal, the fourth input terminal is connected to the output terminal of the bias voltage line, one end of the feedback capacitor is connected to the fourth input terminal, and the other end is connected to the second output terminal.

8. The signal acquisition circuit according to claim 1, characterized in that: The bias voltage line includes a plurality of bias voltage branch lines and a bias voltage bus, the output end of each bias voltage branch line is connected to the input end of the bias voltage bus, the output end of the bias voltage bus is connected to the photocurrent collection module, and the plurality of fingerprint pixel circuits are arranged in a plurality of rows and columns; The photoelectric conversion units of the fingerprint pixel circuits in each row are connected to the input end of one of the bias voltage branch lines, or the photoelectric conversion units of the fingerprint pixel circuits in each column are connected to the input end of one of the bias voltage branch lines.

9. The signal acquisition circuit according to claim 1, characterized in that: The bias voltage line includes a plurality of first bias voltage lines and a plurality of second bias voltage lines, at least part of the first bias voltage lines and at least part of the second bias voltage lines are arranged crosswise, the output end of the first bias voltage line is connected to the photocurrent collection module, and the plurality of fingerprint pixel circuits are arranged in a plurality of rows and columns; The photoelectric conversion unit of each row of fingerprint pixel circuits in some rows is connected to one of the first bias voltage lines, and the photoelectric conversion unit of each row of fingerprint pixel circuits in other rows is connected to one of the second bias voltage lines, or the photoelectric conversion unit of each column of fingerprint pixel circuits in some columns is connected to one of the first bias voltage lines, and the photoelectric conversion unit of each column of fingerprint pixel circuits in other columns is connected to one of the second bias voltage lines.

10. A signal acquisition method, characterized in that: The method is used for a signal acquisition circuit, the signal acquisition circuit comprises: a bias voltage line, a plurality of fingerprint pixel circuits and a photocurrent acquisition module, each of the fingerprint pixel circuits comprises a photoelectric conversion unit, the photoelectric conversion unit and the photocurrent acquisition module are both connected to the bias voltage line, and the signal acquisition method comprises: outputting a photocurrent signal to the bias voltage line through the photoelectric conversion unit when illuminated; Collecting at least part of the photocurrent signal output by the bias voltage line of the photoelectric conversion unit through the photocurrent collection module, and determining the light intensity according to the photocurrent signal; The bias voltage line is used to provide a bias voltage for the photoelectric conversion unit to enable the photoelectric conversion unit to work; Each of the fingerprint pixel circuits further includes a switch connected to the photoelectric conversion unit; the signal acquisition circuit further includes: a driving module connected to the switch and a fingerprint signal reading module connected to the switch; the method further includes: When detecting a fingerprint, the driving module drives the switch element to conduct the fingerprint signal reading module and the photoelectric conversion unit, so that the fingerprint signal reading module reads the fingerprint signal collected by the photoelectric conversion unit.

11. The method according to claim 10, characterized in that The photocurrent collection module includes: a power supply end, a feedback circuit, a voltage divider circuit and a voltage regulator, the voltage regulator includes a control end, a first connection end and a second connection end, the control end is connected to the feedback circuit, the first connection end is connected to the power supply end, the second connection end is connected to the voltage divider circuit, the voltage divider circuit is connected to a ground end and the feedback circuit, and a bias voltage point between the second connection end and the voltage divider circuit is connected to the bias voltage line; the method further includes: Dividing the voltage at the bias voltage point by the voltage divider circuit to obtain a feedback voltage; The feedback circuit outputs a voltage regulating signal to the voltage regulating component based on the feedback voltage, so that the voltage regulating component regulates the voltage of the second connection terminal.

12. The method according to claim 11, characterized in that The voltage-dividing circuit comprises a first voltage-dividing resistor and a second voltage-dividing resistor connected in series, the first voltage-dividing resistor is connected to the second connection end, and the second voltage-dividing resistor is connected to the ground end; One end of the feedback circuit is connected between the first voltage-dividing resistor and the second voltage-dividing resistor; The photocurrent collection module further includes: a voltage detector; the method further includes: The voltage of the second voltage dividing resistor is detected by the voltage detector.

13. An electronic device, characterized in that: The electronic device comprises the signal acquisition circuit according to any one of claims 1 to 9.

14. The electronic device according to claim 13, characterized in that: The electronic device comprises a display screen, and the signal acquisition circuit is arranged on the back side of the display screen.

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