WO2020199748A1 - 超声传感器像素电路及其驱动方法以及显示面板 - Google Patents

超声传感器像素电路及其驱动方法以及显示面板 Download PDF

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Publication number
WO2020199748A1
WO2020199748A1 PCT/CN2020/074356 CN2020074356W WO2020199748A1 WO 2020199748 A1 WO2020199748 A1 WO 2020199748A1 CN 2020074356 W CN2020074356 W CN 2020074356W WO 2020199748 A1 WO2020199748 A1 WO 2020199748A1
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Prior art keywords
ultrasonic sensor
signal
terminal
ultrasonic
potential
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PCT/CN2020/074356
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English (en)
French (fr)
Inventor
丁小梁
王海生
刘英明
陈博
王鹏鹏
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京东方科技集团股份有限公司
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Priority to US16/964,192 priority Critical patent/US11398106B2/en
Publication of WO2020199748A1 publication Critical patent/WO2020199748A1/zh

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
    • G01S15/88—Sonar systems specially adapted for specific applications
    • G01S15/89—Sonar systems specially adapted for specific applications for mapping or imaging
    • G01S15/8906—Short-range imaging systems; Acoustic microscope systems using pulse-echo techniques
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
    • B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
    • B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
    • B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
    • B06B1/0207—Driving circuits
    • B06B1/0215—Driving circuits for generating pulses, e.g. bursts of oscillations, envelopes
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/52—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S15/00
    • G01S7/52017—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S15/00 particularly adapted to short-range imaging
    • G01S7/52079—Constructional features
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
    • G06V40/00—Recognition of biometric, human-related or animal-related patterns in image or video data
    • G06V40/10—Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands
    • G06V40/12—Fingerprints or palmprints
    • G06V40/13—Sensors therefor
    • G06V40/1306—Sensors therefor non-optical, e.g. ultrasonic or capacitive sensing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
    • B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
    • B06B2201/00—Indexing scheme associated with B06B1/0207 for details covered by B06B1/0207 but not provided for in any of its subgroups
    • B06B2201/50—Application to a particular transducer type
    • B06B2201/55—Piezoelectric transducer
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
    • B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
    • B06B2201/00—Indexing scheme associated with B06B1/0207 for details covered by B06B1/0207 but not provided for in any of its subgroups
    • B06B2201/70—Specific application
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
    • G06V40/00—Recognition of biometric, human-related or animal-related patterns in image or video data
    • G06V40/10—Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands
    • G06V40/12—Fingerprints or palmprints
    • G06V40/1347—Preprocessing; Feature extraction
    • G06V40/1359—Extracting features related to ridge properties; Determining the fingerprint type, e.g. whorl or loop

Definitions

  • the present application relates to the field of display technology, and in particular to an ultrasonic sensor pixel circuit and a driving method thereof, and a display panel.
  • part of fingerprint recognition is based on ultrasonic technology.
  • the main principle is: when the transmitted wave touches an object, such as a finger, because the finger has valleys and ridges, the vibration intensity of the reflected wave will be different. Therefore, by detecting the reflected wave The vibration intensity can determine the position of the valley ridge, and then realize fingerprint recognition.
  • fingerprint identification is usually realized by detecting the half wave of the reflected wave.
  • the related art has a problem in that the accuracy of fingerprint identification is low.
  • This application aims to solve one of the technical problems in the related technology at least to a certain extent.
  • the first purpose of this application is to propose an ultrasonic sensor pixel circuit to realize the detection of the complete amplitude of the ultrasonic echo signal.
  • the second purpose of this application is to provide a display panel.
  • the third purpose of the application is to provide a driving method for the pixel circuit of an ultrasonic sensor.
  • an embodiment of the first aspect of the present application proposes an ultrasonic sensor pixel circuit, including a detection module, a first end of the detection module is connected to an ultrasonic sensing unit, and a second end of the detection module is connected to the ultrasonic sensor unit.
  • the first signal terminal is connected, and the detection module is used to generate a detection voltage according to the electric signal output by the ultrasonic sensor unit under the control of the first signal terminal, wherein the electric signal is received according to the ultrasonic sensor unit Ultrasonic signal generated by finger feedback; output module, the first end of the output module is connected to the third end of the detection module, the second end of the output module is connected to the reading line, the output module It is used to generate an output signal according to the detection voltage and provide the output signal to the read line.
  • the detection module generates a detection voltage according to the electrical signal output by the ultrasonic sensor unit under the control of the first signal terminal, and then the output module generates an output signal according to the detection voltage, and provides the output signal to Read the line. Therefore, the ultrasonic sensor pixel circuit of the embodiment of the present application can detect the peak-to-peak value of the echo signal of the ultrasonic wave fed back by the finger, so as to detect the complete amplitude of the ultrasonic echo signal, thereby improving the accuracy of fingerprint recognition.
  • the detection module includes: a pull-up unit connected to the ultrasonic sensing unit and the first signal terminal, and the pull-up unit is configured to Under the control of a signal terminal, the electrical signal output by the ultrasonic sensing unit is superimposed on the second potential, so that the trough potential of the electrical signal is at the second potential; a potential preservation unit, the potential preservation unit and The pull-up unit is connected, and the potential storage unit is configured to generate the detection voltage according to the electrical signal superimposed on the second potential, wherein the detection voltage is the difference between the second potential and the peak-to-peak value of the electrical signal with.
  • the pull-up unit includes a first diode, the anode of the first diode is connected to the first signal terminal, and the cathode of the first diode is connected to the The ultrasonic sensing unit is connected.
  • the potential preservation unit includes a second diode, the anode of the second diode is connected to the cathode of the first diode, and the cathode of the second diode is As the third end of the detection module.
  • the ultrasonic sensor pixel circuit further includes: an ultrasonic emission control module, the ultrasonic emission control module is connected to the ultrasonic sensing unit and the emission control terminal, and the ultrasonic emission control module is located in the The first potential is applied to the ultrasonic sensor unit under the control of the emission control terminal.
  • the ultrasonic sensor pixel circuit further includes a reset module connected to the third terminal and the reset terminal of the detection module, and the reset module is under the control of the reset terminal.
  • the third end of the detection module is set to the second potential.
  • the ultrasonic emission control module includes: a first transistor, a first electrode of the first transistor is connected to the ultrasonic sensor unit, and a second electrode of the first transistor is connected to the ultrasonic sensor unit.
  • the first signal terminal is connected, and the control electrode of the first transistor is connected to the emission control terminal.
  • the output module includes a driving unit that generates the output signal according to the detection voltage, wherein the driving unit includes a second transistor, and the first transistor of the second transistor The electrode is connected to the first power source, the second electrode of the second transistor is connected to the read line, and the control electrode of the second transistor is connected to the third end of the detection module.
  • the output module further includes a reading unit connected between the driving unit and the reading line, the reading unit is also connected to a reading terminal, and the reading unit For providing the output signal to the read line under the control of the read terminal, wherein the read unit includes a third transistor, the first electrode of the third transistor and the second transistor The second electrode of the third transistor is connected to the read line, and the control electrode of the third transistor is connected to the read terminal.
  • the reset module includes: a fourth transistor, a first electrode of the fourth transistor is connected to a second signal terminal, and a second electrode of the fourth transistor is connected to the second signal terminal of the detection module. The three terminals are connected, and the control electrode of the fourth transistor is connected to the reset terminal.
  • an embodiment of the second aspect of the present application proposes a display panel, which includes a plurality of ultrasonic sensor pixel circuits as described in the embodiment of the first aspect of the present application.
  • the ultrasonic sensor pixel circuit is provided to detect the peak-to-peak value of the echo signal of the ultrasonic wave fed back by the finger, so as to detect the complete amplitude of the ultrasonic echo signal, thereby improving the fingerprint Accuracy of recognition.
  • the plurality of ultrasonic sensor pixel circuits are integrated and arranged in the pixel circuit layer of the display panel, or the plurality of ultrasonic sensor pixel circuits are arranged under the pixel circuit layer of the display panel .
  • an embodiment of the third aspect of the present application proposes a driving method for an ultrasonic sensor pixel circuit, which includes the following steps: in the first detection stage, a detection voltage is generated according to the electrical signal output by the ultrasonic sensor unit, wherein The electrical signal is generated according to the ultrasonic signal fed back by the finger received by the ultrasonic sensor unit; in the second detection stage, an output signal is generated according to the detection voltage, and the output signal is provided to the reading line.
  • the detection voltage is first generated according to the electrical signal output by the ultrasonic sensor unit, and then the output signal is generated according to the detection voltage, and the output signal is provided to the read line. Therefore, the driving method of the ultrasonic sensor pixel circuit of the embodiment of the present application can detect the peak-to-peak value of the echo signal of the ultrasonic wave fed back by the finger, so as to detect the complete amplitude of the ultrasonic echo signal, thereby improving the accuracy of fingerprint recognition .
  • the method before the first detection stage, further includes: in the third detection stage, setting the third terminal of the detection module to a second potential, wherein the third terminal of the detection module is used To provide the detection voltage.
  • the first detection stage before the first detection stage, it further includes: in the ultrasonic emission stage, applying a first potential to the ultrasonic sensing unit; after the second detection stage, it further includes: In the reset phase, the third terminal of the detection module is set to the second potential, wherein the third terminal of the detection module is used to provide the detection voltage.
  • Fig. 1 is a schematic block diagram of an ultrasonic sensor pixel circuit according to an embodiment of the present application
  • FIG. 2 is a schematic diagram of the position of the ultrasonic sensing unit in the ultrasonic sensor pixel circuit according to an embodiment of the present application
  • FIG. 3 is a schematic diagram of the position of the ultrasonic sensor unit in the ultrasonic sensor pixel circuit according to another embodiment of the present application;
  • FIG. 4 is a schematic diagram of the working principle of the ultrasonic sensor unit in the ultrasonic sensor pixel circuit according to an embodiment of the present application;
  • FIG. 5 is a schematic block diagram of an ultrasonic sensor pixel circuit according to an embodiment of the present application.
  • FIG. 6 is a schematic block diagram of a pixel circuit of an ultrasonic sensor according to another embodiment of the present application.
  • Fig. 7 is a circuit schematic diagram of a pixel circuit of an ultrasonic sensor according to an embodiment of the present application.
  • FIG. 8 is a control sequence diagram of a pixel circuit of an ultrasonic sensor according to an embodiment of the present application.
  • FIG. 9 is a circuit schematic diagram of a pixel circuit of an ultrasonic sensor according to another embodiment of the present application.
  • FIG. 10 is a control timing diagram of a pixel circuit of an ultrasonic sensor according to another embodiment of the present application.
  • FIG. 11 is a schematic flowchart of a driving method of an ultrasonic sensor pixel circuit according to an embodiment of the present application.
  • FIG. 12 is a schematic flowchart of a driving method of an ultrasonic sensor pixel circuit according to a specific embodiment of the present application.
  • FIG. 13 is a schematic flowchart of a driving method of an ultrasonic sensor pixel circuit according to another specific embodiment of the present application.
  • Fig. 1 is a schematic block diagram of an ultrasonic sensor pixel circuit according to an embodiment of the present application.
  • the ultrasonic sensor pixel circuit of the embodiment of the present application includes a detection module 10 and an output module 20.
  • the first end of the detection module 10 is connected to the ultrasonic sensor unit 30, the second end of the detection module 10 is connected to the first signal terminal Vbias1, and the detection module 10 is used to control the ultrasonic sensor under the control of the first signal terminal Vbias1.
  • the electrical signal output by the unit 30 generates a detection voltage, where the electrical signal is generated according to the ultrasonic signal received by the ultrasonic sensor unit 30 and fed back by the finger.
  • the ultrasonic sensing unit 30 may adopt a piezoelectric sandwich structure.
  • the ultrasonic sensing unit 30 may include a piezoelectric component PVDF, a first electrode (or cathode) TX, and a second electrode. (Or anode) RX, the piezoelectric component PVDF is arranged between the first electrode TX and the second electrode RX.
  • a sine wave signal such as a high-voltage sine wave signal, can be applied to the first electrode TX, and a fixed voltage is applied to the second electrode RX.
  • the piezoelectric component PVDF is excited by the voltage to produce an inverse piezoelectric effect, outward When transmitting ultrasonic waves, it reflects when it touches an object such as a finger. Because the fingerprint of the finger is divided into valleys and ridges, the vibration intensity of the echo is different. At this time, stop applying the high-voltage sine wave signal to the first electrode TX. In order to apply a fixed voltage, the piezoelectric component PVDF is affected by the echo feedback from the finger. Due to the positive piezoelectric effect, an AC electrical signal is generated on the second electrode RX. The finger can be determined by measuring the amplitude of the electrical signal The position of the valley ridge, and then realize the ultrasonic fingerprint recognition.
  • the ultrasonic sensing structure can be constructed by P ⁇ Q ultrasonic sensing units 30, that is, the ultrasonic sensing structure has P rows and Q columns of ultrasonic sensing units 30, as shown in FIGS.
  • the piezoelectric component PVDF in the unit 30 can form the piezoelectric layer 301 of the ultrasonic sensing structure
  • the first electrode TX can form the TX layer 302 of the ultrasonic sensing structure
  • the second electrode RX can form the RX layer 303 of the ultrasonic sensing structure.
  • the piezoelectric layer 301 is located between the TX layer 302 and the RX layer 303, that is, the TX layer 302 and the RX layer 303 are respectively arranged on both sides of the piezoelectric layer 301.
  • the ultrasonic sensing structure can be combined with a display panel such as an OLED (Organic Light Emitting Display) display panel.
  • a display panel such as an OLED (Organic Light Emitting Display) display panel.
  • OLED Organic Light Emitting Display
  • a highly integrated layered structure as shown in FIG. 2 can be used.
  • the ultrasonic The sensing structure and the ultrasonic sensor pixel circuit are added to the display module, that is, the ultrasonic sensor pixel circuit and the RX layer 303 of the ultrasonic sensing structure can be integrated in the pixel circuit layer (ie, the pixel array layer) of the display module That is, the Pixel array layer in Figure 2 can serve as both a pixel circuit layer for display and an ultrasonic sensor pixel circuit for ultrasonic fingerprint recognition.
  • the piezoelectric layer 301 and TX layer 302 of the ultrasonic sensing structure can be set on the Pixel array. Below the layer.
  • a structure with reduced integration as shown in FIG. 3 can also be used.
  • the ultrasonic sensor structure and the ultrasonic sensor pixel circuit are placed under the display module, for example, the ultrasonic sensor structure and the ultrasonic sensor
  • the sensor pixel circuit is externally arranged under the display module, that is, the display pixel circuit is arranged on the Pixel array layer, that is, the Pixel array layer in Figure 3 serves as the pixel circuit layer for display, and the ultrasonic sensor pixel circuit and
  • the RX layer 303 of the ultrasonic sensing structure is independently arranged on the Pixel array1 layer, that is, the Pixel array1 layer in Figure 3 serves as the ultrasonic fingerprint recognition pixel circuit layer, and the piezoelectric layer 301 and TX layer 302 of the ultrasonic sensing structure can be arranged on the Pixel array1 Above the layer.
  • the electrical signal output by the ultrasonic sensor unit 30 may be a sine wave electrical signal.
  • the first end of the output module 20 is connected to the third end of the detection module 10, and the second end of the output module 20 is connected to the read line RL.
  • the output module 20 is used to generate an output signal according to the detection voltage, and The output signal is supplied to the read line RL.
  • the reading line RL is also connected to an external detection circuit, and the output signal can be sent to the external detection circuit through the reading line RL, and the external detection circuit can determine the valley or ridge of the finger fingerprint according to the received output signal.
  • the output signal may indicate the intensity and magnitude of the ultrasonic wave incident on the ultrasonic sensor unit 30 after being reflected by the finger.
  • the detection module 10 under the control of the first signal terminal Vbias1, the detection module 10 generates a detection voltage according to the electrical signal output by the ultrasonic sensing unit 30, such as a sine wave electrical signal, and then the output module 20 generates an output signal according to the detection voltage, and outputs the signal It is provided to the reading line RL to read the output signal. Therefore, by detecting the peak-to-peak value of the ultrasonic signal fed back by the finger, high-precision ultrasonic fingerprint recognition can be realized.
  • the detection of the output signal of the aforementioned ultrasonic sensor pixel circuit mainly includes two detection stages:
  • the detection voltage is generated according to the electrical signal output by the ultrasonic sensor unit 30, wherein the electrical signal is generated according to the ultrasonic signal received by the ultrasonic sensor unit 30 and fed back by the finger.
  • an output signal is generated according to the detection voltage, and the output signal is provided to the read line RL.
  • the detection module 10 in the first detection stage, under the control of the first signal terminal Vbias1, the detection module 10 generates a detection voltage according to the electrical signal output by the ultrasonic sensor unit 30, such as a sine wave signal, and then, in the second detection stage, outputs The module 20 generates an output signal according to the detection voltage generated by the detection module 10, and provides the output signal to the reading line RL, thereby achieving high-precision ultrasonic fingerprint recognition.
  • the detection module 10 includes: a pull-up unit 101 and a potential storage unit 102, a pull-up unit 101 and an ultrasonic sensing unit 30, and a first signal terminal Vbias1 Connected, the pull-up unit 101 is used to superimpose the electrical signal output by the ultrasonic sensing unit 30 onto the second potential under the control of the first signal terminal Vbias1, so that the valley potential of the electrical signal is at the second potential; the potential saving unit 102 is connected to the pull-up unit 101, and the potential storage unit 102 is used to generate a detection voltage according to the electrical signal superimposed on the second potential, where the detection voltage is the sum of the second potential and the peak-to-peak value of the electrical signal, and the second potential is high In the first potential.
  • the peak-to-peak value of the electrical signal may be the difference obtained by subtracting the peak value of the electrical signal from the trough value of the electrical signal.
  • the electrical signal output by the ultrasonic sensor unit 30 may be a sine wave electrical signal.
  • the pull-up unit 101 superimposes the electrical signal output by the ultrasonic sensor unit 30, that is, the sine wave signal, on the second potential under the control of the first signal terminal Vbias1, and further, the potential storage unit 102
  • the detection voltage is generated according to the electric signal superimposed on the second potential, and then, in the second detection stage, the output module 20 generates an output signal according to the detection voltage generated by the potential holding unit 102 and provides the output signal to the read line RL.
  • the sine wave signal when the sine wave signal is superimposed on the second potential, the sine wave signal is translated as a whole and the trough of the sine wave signal is located at the second potential.
  • the ultrasonic sensor pixel circuit further includes an ultrasonic emission control module 40.
  • the ultrasonic emission control module 40 is connected to the ultrasonic sensing unit 30 and the emission control terminal IN.
  • the emission control module 40 applies the first potential to the ultrasonic sensing unit 30 under the control of the emission control terminal IN.
  • the first potential is a low-level potential.
  • the ultrasonic emission control module 40 can be connected to the second electrode RX in the ultrasonic sensing unit 30, and the ultrasonic emission control module 40 is under the control of the emission control terminal IN.
  • the first potential that is, the low-level potential, is applied to the second electrode RX in the ultrasonic sensor unit 30.
  • the ultrasonic emission control module 40 applies the first potential, that is, the low-level potential, to the ultrasonic sensor unit 30 under the control of the emission control terminal IN. Specifically, it is applied to the second electrode RX in the ultrasonic sensing unit 30 so that the second electrode RX in the ultrasonic sensing unit 30 is maintained at a fixed potential.
  • the ultrasonic sensor pixel circuit further includes a reset module 50, which is connected to the third terminal of the detection module 10 and the reset terminal RESET, and the reset module 50 Under the control of the reset terminal RESET, the third terminal of the detection module 10 is set to the second potential.
  • the reset module 50 sets the third terminal of the detection module 10 to the second potential under the control of the reset terminal RESET to control the third terminal of the detection module 10.
  • the third terminal of the detection module 10 is used to provide a detection voltage.
  • the pull-up unit 101 includes a first diode D1, the anode of the first diode D1 is connected to the first signal terminal Vbias1, and the cathode of the first diode D1 Connected to the ultrasonic sensor unit 30.
  • the potential preservation unit 102 includes a second diode D2, the anode of the second diode D2 is connected to the cathode of the first diode D1, and the second diode The cathode of D2 serves as the third end of the detection module 10.
  • the ultrasonic emission control module 40 includes: a first transistor T1, a first electrode of the first transistor T1 is connected to the ultrasonic sensor unit 30, and a second electrode of the first transistor T1 It is connected to the first signal terminal Vbias1, and the control electrode of the first transistor T1 is connected to the emission control terminal IN.
  • the first transistor T1 may be a reset transistor.
  • the output module 20 includes a driving unit 201 that generates an output signal according to the detection voltage.
  • the driving unit 201 includes a second transistor T2, and the first transistor T2 The electrode is connected to the first power source ELVSS, the second electrode of the second transistor T2 is connected to the read line RL, and the control electrode of the second transistor T2 is connected to the third end of the detection module 10.
  • the driving unit 201 can directly provide the generated output signal to the reading line RL to realize ultrasonic fingerprint recognition.
  • the second transistor T2 may be a gate voltage control device, and the specific type is determined by the type of the external detection circuit connected to the read line RL. If the external detection circuit is a current-type detection circuit, the second transistor T2 is The gate voltage controls the current type device. If the external detection circuit is a voltage type detection circuit, the second transistor T2 is a source follower device. Wherein, taking the second transistor T2 as a gate voltage control current type device as an example, the output signal generated by the output module 20 according to the detected voltage may be a current signal, which can reflect the complete magnitude of the amplitude of the echo signal fed back by the finger , To achieve the detection of the complete amplitude of the ultrasonic echo signal, thereby improving the accuracy of ultrasonic fingerprint recognition.
  • the reset module 50 includes: a fourth transistor T4, a first pole of the fourth transistor T4 is connected to the second signal terminal Vbias2, and a second pole of the fourth transistor T4 is connected to the detection
  • the third terminal of the module 10 is connected, and the control electrode of the fourth transistor T4 is connected to the reset terminal RESET.
  • the fourth transistor T4 may be a reset transistor.
  • the fourth transistor T4 is turned on, so that the voltage signal input from the second signal terminal Vbias2, such as the second potential, is written into the third terminal of the detection module 10, and the detection module The third terminal of 10 is set to the second potential to reset the third terminal of the detection module 10.
  • the first transistor T1, the second transistor T2, and the fourth transistor T4 can be either NPN transistors or PNP transistors.
  • the NPN transistors are N-type transistors.
  • the PNP transistor is a P-type transistor, and it turns on when it is low.
  • the ultrasonic sensor pixel circuit of the embodiment of the present application is described by taking the first transistor T1, the second transistor T2, and the fourth transistor T4 as NPN transistors as an example.
  • a third detection phase is included before the first detection phase.
  • the fourth transistor T4 under the control of the reset terminal RESET, the fourth transistor T4 is turned on, thereby inputting the second signal terminal Vbias2
  • the voltage signal such as the second potential is written into the third terminal of the detection module 10, and the third terminal of the detection module 10 is set to the second potential.
  • S1 can be the driving signal applied to the first electrode (cathode) in the ultrasonic sensor unit 30
  • IN1 can be the input signal of the emission control terminal IN
  • RESET1 can be the input signal of the reset terminal RESET
  • Vbias11 can be the first
  • the input signal of the signal terminal Vbias1, Vbias21 may be the input signal of the second signal terminal Vbias2.
  • the driving signal S1 applied to the first electrode TX in the ultrasonic sensing unit 30 is a sine wave signal, and the transmitting control terminal IN inputs a high level signal, the first transistor T1 is turned on, and the first signal
  • the first potential input from the terminal Vbias1, that is, the low-level potential is applied to the ultrasonic sensing unit 30, specifically, to the second electrode RX in the ultrasonic sensing unit 30, so that the second electrode RX is maintained at a fixed potential.
  • the piezoelectric component in the ultrasonic sensor unit 30 generates an inverse piezoelectric effect due to the excitation of the voltage, and emits ultrasonic waves outward.
  • the ultrasonic transmission phase t0 After the ultrasonic transmission phase t0 is over, stop applying a sine wave signal to the first electrode TX in the ultrasonic sensor unit 30, that is, the driving signal S1 becomes a fixed level. At this time, the transmitted wave is reflected when it touches an object such as a finger. , And then the piezoelectric component in the ultrasonic sensor unit 30 is affected by the echo fed back by the finger. Due to the positive piezoelectric effect, an alternating current signal is generated on the second electrode RX, that is, an alternating current signal is generated at point A. At the same time, the emission control terminal IN inputs a low-level signal, the first transistor T1 is turned off, and the valley potential of the AC signal generated at point A is determined by the potential of the first signal terminal Vbias1.
  • the potential of the second signal terminal Vbias2 becomes the second potential.
  • the second signal terminal IN becomes the low level signal after the first preset time is reached
  • the second The potential of the signal terminal Vbias2 becomes the second potential.
  • the second potential can be the static operating point of the second transistor T2
  • the reset terminal RESET inputs a high level signal
  • the fourth transistor T4 is turned on
  • the input signal of the second signal terminal Vbias2, that is, the second potential is written into the detection module
  • the third terminal of 10 is the cathode of the second diode D2, so that point B is at the static operating point of the second transistor T2. After that, the reset terminal RESET is pulled low, and the fourth transistor T4 is turned off.
  • the potential of the first signal terminal Vbias1 is pulled up. It should be noted that the first signal terminal Vbias1 may be pulled up after the reset terminal RESET becomes a low-level signal for the second preset time.
  • the potential of the first signal terminal Vbias1 is at the second potential.
  • the sine wave electrical signal at point A is superimposed on the second potential, making the sine wave electrical
  • the valley potential of the signal is at the second potential, that is, the potential at point A is raised above the static operating point of the second transistor T2, and then the potential of the first signal terminal Vbias1 is pulled down to prevent leakage.
  • the function of the pole tube D2, point B can store the peak-to-peak value of the sine wave electrical signal.
  • the diode when the anode potential of the diode is higher than the cathode potential, the diode is turned on, so that the cathode potential of the diode is basically the same as the anode potential, and when the anode potential of the diode is lower than the cathode potential, the diode is turned off.
  • the cathode potential of D2 can remain unchanged and will not decrease with the decrease of anode potential.
  • the second diode D2 when the peak of the sine wave electrical signal at point A is provided to the anode of the second diode D2, the second diode D2 The cathode potential is raised to the sum of the second potential and the peak-to-peak value of the sine wave electrical signal at point A, that is, the potential at point B can be raised to the sum of the second potential and the peak-to-peak value of the sine wave electrical signal at point A, Then the potential at point B remains unchanged at this potential, which is the detection voltage.
  • the second transistor T2 In the second detection phase t2, the second transistor T2 generates an output signal, that is, a current signal, according to the detection voltage at point B, and provides the output signal, that is, a current signal to the reading line RL, and the external detection circuit can determine the sine wave according to the output signal The peak-to-peak value of the signal can then determine the valley or ridge of the finger fingerprint, thereby realizing high-precision ultrasonic fingerprint recognition.
  • the input signal of the second signal terminal Vbias2 changes to the second potential
  • the reset terminal RESET inputs a high level signal
  • the fourth transistor T4 is turned on
  • the input signal of the second signal terminal Vbias2 is written into the second potential
  • the third terminal of the detection module 10 is the cathode of the second diode D2 to reset point B.
  • the structure of the ultrasonic sensor pixel circuit of the embodiment of FIG. 9 is different from the embodiment of FIG. 7 in that, in addition to the driving unit 201, the output module 20 also includes a reading unit 202. As shown in FIG. 9, the output module 20 also includes a connection In the reading unit 202 between the driving unit 201 and the reading line RL, the reading unit 202 is also connected to the reading terminal RD, and the reading unit 202 is used to provide an output signal to the reading under the control of the reading terminal RD.
  • Line RL where the reading unit 202 includes a third transistor T3, the first pole of the third transistor T3 is connected to the second pole of the second transistor T2, and the second stage of the third transistor T3 is connected to the reading line RL.
  • the control electrode of the three transistor T3 is connected to the read terminal RD.
  • the reading unit 202 can provide an output signal to the reading line RL under the control of the reading terminal RD to realize ultrasonic fingerprint recognition.
  • the third transistor T3 can be a strobe transistor for reading in a strobe row.
  • the row and column reading mode is adopted, that is, when the row strobe is turned on, the reading line RL corresponding to each column reads the signal. After the reading of the current row is completed, the next row is turned on. Three transistor T3, and so on.
  • S1 can be the driving signal applied by the first electrode (cathode) in the ultrasonic sensor unit 30
  • IN1 can be the input signal of the emission control terminal IN
  • RD1 can be the input signal of the reading terminal RD
  • RESET1 can be the reset terminal
  • Vbias11 may be the input signal of the first signal terminal Vbias1
  • Vbias21 may be the input signal of the second signal terminal Vbias2.
  • the driving signal S1 applied to the first electrode TX in the ultrasonic sensing unit 30 is a sine wave signal, and the transmitting control terminal IN inputs a high level signal, the first transistor T1 is turned on, and the first signal
  • the first potential input from the terminal Vbias1, that is, the low-level potential is applied to the ultrasonic sensing unit 30, specifically, to the second electrode RX in the ultrasonic sensing unit 30, so that the second electrode RX is maintained at a fixed potential.
  • the piezoelectric component in the ultrasonic sensor unit 30 generates an inverse piezoelectric effect due to the excitation of the voltage, and emits ultrasonic waves outward.
  • the ultrasonic transmission phase t0 After the ultrasonic transmission phase t0 is over, stop applying a sine wave signal to the first electrode TX in the ultrasonic sensor unit 30, that is, the driving signal S1 becomes a fixed level. At this time, the transmitted wave is reflected when it touches an object such as a finger. Then, the piezoelectric component in the ultrasonic sensor unit 30 is affected by the echo fed back by the finger. Due to the positive piezoelectric effect, an alternating current signal is generated on the second electrode RX, that is, an alternating current signal is generated at point A. At the same time, the emission control terminal IN inputs a low-level signal, the first transistor T1 is turned off, and the valley potential of the AC signal generated at point A is determined by the potential of the first signal terminal Vbias1.
  • the potential of the first signal terminal Vbias1 is pulled up so that the potential of the first signal terminal Vbias1 is at the second potential.
  • a The sine wave electrical signal at point is superimposed on the second potential, so that the valley potential of the sine wave electrical signal is at the second potential, that is, the potential at point A is raised to above the static operating point of the second transistor T2, where, The second potential can be the static operating point of the second transistor T2, and then lower the potential of the first signal terminal Vbias1 to prevent leakage.
  • point B can store sine wave electricity The peak-to-peak value of the signal.
  • the diode when the anode potential of the diode is higher than the cathode potential, the diode is turned on, so that the cathode potential of the diode is basically the same as the anode potential, and when the anode potential of the diode is lower than the cathode potential, the diode is turned off.
  • the cathode potential of D2 can remain unchanged and will not decrease with the decrease of anode potential.
  • the second diode D2 when the peak of the sine wave electrical signal at point A is provided to the anode of the second diode D2, the second diode D2 The cathode potential is raised to the sum of the second potential and the peak-to-peak value of the sine wave electrical signal at point A, that is, the potential at point B can be raised to the sum of the second potential and the peak-to-peak value of the sine wave electrical signal at point A, Then the potential at point B remains unchanged at this potential, which is the detection voltage.
  • the ultrasonic sensor unit 30 since the ultrasonic sensor unit 30 is arranged inside the display panel, the emitted wave will also touch other objects such as the display screen before touching the finger, and the piezoelectric components in the ultrasonic sensor unit 30 are subjected to stress. Before the influence of the finger feedback echo, it will also be affected by the echo feedback through the display screen, and due to the positive piezoelectric effect, an alternating current signal is generated on the second electrode RX, that is, an alternating current signal is generated at point A, so It is necessary to delay the preset time and pull up the potential of the first signal terminal Vbias1 to ensure that the AC signal at point A at this time is generated based on the echo signal fed back by the finger, thereby making the ultrasonic fingerprint recognition more accurate.
  • the preset time may be determined according to the time of the echo signal fed back by the finger received by the ultrasonic sensor unit 30.
  • the second transistor T2 In the second detection stage t2, the second transistor T2 generates an output signal, that is, a current signal, according to the detection voltage at point B, the read terminal RD inputs a high-level signal, the third transistor T3 is turned on, and the output signal, that is, a current signal is provided to
  • the read line RL and the external detection circuit can determine the peak-to-peak value of the sine wave signal according to the output signal, and then determine the valley or ridge of the finger fingerprint, so as to realize high-precision ultrasonic fingerprint recognition.
  • the input signal of the second signal terminal Vbias2 becomes the second potential
  • the reset terminal RESET inputs a high level signal
  • the fourth transistor T4 is turned on
  • the input signal of the second signal terminal Vbias2 is written into the second potential
  • the third terminal of the detection module 10 is the cathode of the second diode D2 to reset point B.
  • the detection module generates a detection voltage according to the electrical signal output by the ultrasonic sensing unit under the control of the first signal terminal, and then the output module generates an output signal according to the detection voltage, and outputs The signal is provided to the read line. Therefore, the ultrasonic sensor pixel circuit of the embodiment of the present application can detect the peak-to-peak value of the echo signal of the ultrasonic wave fed back by the finger, so as to detect the complete amplitude of the ultrasonic echo signal, thereby improving the accuracy of fingerprint recognition.
  • an embodiment of the present application also proposes a display panel including the foregoing ultrasonic sensor pixel circuit.
  • a plurality of ultrasonic sensor pixel circuits are integrated and arranged in the pixel circuit layer of the display panel, or a plurality of ultrasonic sensor pixel circuits are arranged under the pixel circuit layer of the display panel.
  • the ultrasonic sensor pixel circuit is provided to detect the peak-to-peak value of the echo signal of the ultrasonic wave fed back by the finger, so as to detect the complete amplitude of the ultrasonic echo signal, thereby improving the fingerprint Accuracy of recognition.
  • an embodiment of the present application also proposes a driving method of the ultrasonic sensor pixel circuit.
  • FIG. 11 is a schematic flowchart of a driving method of an ultrasonic sensor pixel circuit according to an embodiment of the present application. As shown in FIG. 11, the driving method of an ultrasonic sensor pixel circuit of an embodiment of the present application includes the following steps:
  • a detection voltage is generated according to the electrical signal output by the ultrasonic sensor unit, where the electrical signal is generated according to the ultrasonic signal received by the ultrasonic sensor unit and fed back by the finger.
  • the first detection stage before the first detection stage, it further includes: in the ultrasonic emission stage, applying the first potential to the ultrasonic sensor unit; after the second detection stage, it further includes: in the reset stage, detecting The third terminal of the module is set to the second potential, and the third terminal of the detection module is used to provide a detection voltage.
  • the first detection stage before the first detection stage, it further includes: in the third detection stage, setting the third terminal of the detection module to the second potential, wherein the third terminal of the detection module is used to provide a detection voltage .
  • the driving method of the ultrasonic sensor pixel circuit of the embodiment of the present application may also be two.
  • the driving method of the ultrasonic sensor pixel circuit corresponding to the embodiment in FIG. 7 includes the following steps:
  • the third terminal of the detection module is set to a second potential, where the third terminal of the detection module is used to provide a detection voltage.
  • a detection voltage is generated according to the electrical signal output by the ultrasonic sensor unit, where the electrical signal is generated according to the ultrasonic signal received by the ultrasonic sensor unit and fed back by the finger.
  • the third terminal of the detection module is set to the second potential, where the third terminal of the detection module is used to provide a detection voltage.
  • the driving method of the ultrasonic sensor pixel circuit corresponding to the embodiment in FIG. 9 includes the following steps:
  • a detection voltage is generated according to the electrical signal output by the ultrasonic sensing unit, where the electrical signal is generated based on the ultrasonic signal fed back by the finger received by the ultrasonic sensing unit.
  • the third terminal of the detection module is set to a second potential, where the third terminal of the detection module is used to provide a detection voltage.
  • the driving method of the ultrasonic sensor pixel circuit proposed in the embodiments of the present application, a detection voltage is first generated according to the electrical signal output by the ultrasonic sensor unit, and then an output signal is generated according to the detection voltage, and the output signal is provided to the read line. Therefore, the driving method of the ultrasonic sensor pixel circuit of the embodiment of the present application can detect the peak-to-peak value of the echo signal of the ultrasonic wave fed back by the finger, so as to detect the complete amplitude of the ultrasonic echo signal, thereby improving the accuracy of fingerprint recognition .
  • first and second are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with “first” and “second” may explicitly or implicitly include at least one of the features. In the description of the present application, "a plurality of” means at least two, such as two, three, etc., unless specifically defined otherwise.
  • a "computer-readable medium” can be any device that can contain, store, communicate, propagate, or transmit a program for use by an instruction execution system, device, or device or in combination with these instruction execution systems, devices, or devices.
  • computer readable media include the following: electrical connections (electronic devices) with one or more wiring, portable computer disk cases (magnetic devices), random access memory (RAM), Read only memory (ROM), erasable and editable read only memory (EPROM or flash memory), fiber optic devices, and portable compact disk read only memory (CDROM).
  • the computer-readable medium may even be paper or other suitable media on which the program can be printed, because it can be used, for example, by optically scanning the paper or other media, and then editing, interpreting, or other suitable media if necessary. The program is processed in a manner to obtain the program electronically and then stored in the computer memory.
  • each part of this application can be implemented by hardware, software, firmware, or a combination thereof.
  • multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system.
  • Discrete logic gate circuits for implementing logic functions on data signals Logic circuit, application specific integrated circuit with suitable combinational logic gate, programmable gate array (PGA), field programmable gate array (FPGA), etc.
  • the functional units in the various embodiments of the present application may be integrated into one processing module, or each unit may exist alone physically, or two or more units may be integrated into one module.
  • the above-mentioned integrated modules can be implemented in the form of hardware or software functional modules. If the integrated module is implemented in the form of a software function module and sold or used as an independent product, it may also be stored in a computer readable storage medium.
  • the aforementioned storage medium may be a read-only memory, a magnetic disk or an optical disk, etc.

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Abstract

一种超声传感器像素电路及其驱动方法以及显示面板，其中，电路包括：检测模块（10），检测模块（10）的第一端与超声波传感单元（30）相连，检测模块（10）的第二端与第一信号端（Vbias1）相连，检测模块（10）用于在第一信号端（Vbias1）的控制下根据超声波传感单元（30）输出的电信号生成检测电压；输出模块（20），输出模块（20）的第一端与检测模块（10）的第三端相连，输出模块（20）的第二端与读取线（RL）相连，输出模块（20）用于根据检测电压生成输出信号，并将输出信号提供至读取线（RL），由此，能够对超声波经手指反馈的回波信号的峰峰值进行检测，实现对超声回波信号的完整幅值进行检测，进而提高指纹识别的精度。

Description

超声传感器像素电路及其驱动方法以及显示面板
相关申请的交叉引用
本申请基于申请号为201910261333.2，申请日为2019年04月02日的中国专利申请提出，并要求上述中国专利申请的优先权，上述中国专利申请的全部内容在此引入本申请作为参考。
技术领域
本申请涉及显示技术领域，特别涉及一种超声传感器像素电路及其驱动方法以及显示面板。
背景技术
目前，部分指纹识别基于超声波技术实现，其主要原理为：发射波接触到物体例如手指时，由于手指有谷脊之分，所以反射波的震动强度就会有差异，由此，通过检测反射波的震动强度就可以确定谷脊的位置，进而实现指纹识别。
相关技术中，通常通过检测反射波的半波实现指纹识别，但是，相关技术存在的问题在于，指纹识别的精度较低。
发明内容
本申请旨在至少在一定程度上解决相关技术中的技术问题之一。
为此，本申请的第一个目的在于提出一种超声传感器像素电路，以实现对超声回波信号的完整幅值进行检测。
本申请的第二个目的在于提出一种显示面板。
本申请的第三个目的在于提出一种超声传感器像素电路的驱动方法。
为达上述目的，本申请第一方面实施例提出了一种超声传感器像素电路，包括：检测模块，所述检测模块的第一端与超声波传感单元相连，所述检测模块的第二端与第一信号端相连，所述检测模块用于在所述第一信号端的控制下根据所述超声波传感单元输出的电信号生成检测电压，其中，所述电信号根据所述超声波传感单元接收到的经手指反馈的超声波信号生成；输出模块，所述输出模块的第一端与所述检测模块的第三端相连，所述输出模块的第二端与读取线相连，所述输出模块用于根据所述检测电压生成输出信号，并将所述输出信号提供至所述读取线。
根据本申请实施例提出的超声传感器像素电路，检测模块在第一信号端的控制下根据 超声波传感单元输出的电信号生成检测电压，然后输出模块根据检测电压生成输出信号，并将输出信号提供至读取线。由此，本申请实施例的超声传感器像素电路能够对超声波经手指反馈的回波信号的峰峰值进行检测，实现对超声回波信号的完整幅值进行检测，进而提高指纹识别的精度。
根据本申请的一个实施例，所述检测模块包括：上拉单元，所述上拉单元与所述超声波传感单元和所述第一信号端相连，所述上拉单元用于在所述第一信号端的控制下将所述超声波传感单元输出的电信号叠加到第二电位之上，以使所述电信号的波谷电位处于所述第二电位；电位保存单元，所述电位保存单元与所述上拉单元相连，所述电位保存单元用于根据叠加到第二电位之上的电信号生成所述检测电压，其中，所述检测电压为所述第二电位与电信号的峰峰值之和。
根据本申请的一个实施例，所述上拉单元包括第一二极管，所述第一二极管的阳极与所述第一信号端相连，所述第一二极管的阴极与所述超声波传感单元相连。
根据本申请的一个实施例，所述电位保存单元包括第二二极管，所述第二二极管的阳极与所述第一二极管的阴极相连，所述第二二极管的阴极作为所述检测模块的第三端。
根据本申请的一个实施例，所述的超声传感器像素电路还包括：超声波发射控制模块，所述超声波发射控制模块与所述超声波传感单元和发射控制端相连，所述超声波发射控制模块在所述发射控制端的控制下将第一电位施加到所述超声波传感单元。
根据本申请的一个实施例，所述的超声传感器像素电路还包括：复位模块，所述复位模块与所述检测模块的第三端和复位端相连，所述复位模块在所述复位端的控制下将所述检测模块的第三端置为第二电位。
根据本申请的一个实施例，所述超声波发射控制模块包括：第一晶体管，所述第一晶体管的第一极与所述超声波传感单元相连，所述第一晶体管的第二极与所述第一信号端相连，所述第一晶体管的控制极与所述发射控制端相连。
根据本申请的一个实施例，所述输出模块包括驱动单元，所述驱动单元根据所述检测电压生成所述输出信号，其中，所述驱动单元包括第二晶体管，所述第二晶体管的第一极与第一电源相连，所述第二晶体管的第二极与所述读取线相连，所述第二晶体管的控制极与所述检测模块的第三端相连。
根据本申请的一个实施例，所述输出模块还包括连接在所述驱动单元与所述读取线之间的读取单元，所述读取单元还与读取端相连，所述读取单元用于在所述读取端的控制下将所述输出信号提供至所述读取线，其中，所述读取单元包括第三晶体管，所述第三晶体管的第一极与所述第二晶体管的第二极相连，所述第三晶体管的第二级与所述读取线相连，所述第三晶体管的控制极与读取端相连。
根据本申请的一个实施例，所述复位模块包括：第四晶体管，所述第四晶体管的第一极与第二信号端相连，所述第四晶体管的第二极与所述检测模块的第三端相连，所述第四晶体管的控制极与所述复位端相连。
为达上述目的，本申请第二方面实施例提出了一种显示面板，包括：多个如本申请第一方面实施例所述的超声传感器像素电路。
根据本申请实施例提出的显示面板，通过设置的超声传感器像素电路，能够对超声波经手指反馈的回波信号的峰峰值进行检测，实现对超声回波信号的完整幅值进行检测，进而提高指纹识别的精度。
根据本申请的一个实施例，所述多个超声传感器像素电路集成设置于所述显示面板的像素电路层中，或者，所述多个超声传感器像素电路设置于所述显示面板的像素电路层下方。
为达上述目的，本申请第三方面实施例提出了一种超声传感器像素电路的驱动方法，包括以下步骤：在第一检测阶段，根据超声波传感单元输出的电信号生成检测电压，其中，所述电信号根据所述超声波传感单元接收到的经手指反馈的超声波信号生成；在第二检测阶段，根据所述检测电压生成输出信号，并将所述输出信号提供至读取线。
根据本申请实施例提出的超声传感器像素电路的驱动方法，首先根据超声波传感单元输出的电信号生成检测电压，然后根据检测电压生成输出信号，并将输出信号提供至读取线。由此，本申请实施例的超声传感器像素电路的驱动方法能够对超声波经手指反馈的回波信号的峰峰值进行检测，实现对超声回波信号的完整幅值进行检测，进而提高指纹识别的精度。
根据本申请的一个实施例，在所述第一检测阶段之前，还包括：在第三检测阶段，将检测模块的第三端置为第二电位，其中，所述检测模块的第三端用于提供所述检测电压。
根据本申请的一个实施例，在所述第一检测阶段之前，还包括：在超声波发射阶段，将第一电位施加到所述超声波传感单元；在所述第二检测阶段之后，还包括：在复位阶段，将检测模块的第三端置为第二电位，其中，所述检测模块的第三端用于提供所述检测电压。
本申请附加的方面和优点将在下面的描述中部分给出，部分将从下面的描述中变得明显，或通过本申请的实践了解到。
附图说明
本申请上述的和/或附加的方面和优点从下面结合附图对实施例的描述中将变得明显和容易理解，其中：
图1为根据本申请实施例的超声传感器像素电路的方框示意图；
图2为根据本申请一个实施例的超声传感器像素电路中超声波传感单元的位置示意图；
图3为根据本申请另一个实施例的超声传感器像素电路中超声波传感单元的位置示意图；
图4为根据本申请一个实施例的超声传感器像素电路中的超声波传感单元的工作原理示意图；
图5为根据本申请一个实施例的超声传感器像素电路的方框示意图；
图6为根据本申请另一个实施例的超声传感器像素电路的方框示意图；
图7为根据本申请一个实施例的超声传感器像素电路的电路原理图；
图8为根据本申请一个实施例的超声传感器像素电路的控制时序图；
图9为根据本申请另一个实施例的超声传感器像素电路的电路原理图；
图10为根据本申请另一个实施例的超声传感器像素电路的控制时序图；
图11为根据本申请实施例的超声传感器像素电路的驱动方法的流程示意图；
图12为根据本申请一个具体实施例的超声传感器像素电路的驱动方法的流程示意图；
图13为根据本申请另一个具体实施例的超声传感器像素电路的驱动方法的流程示意图。
具体实施方式
下面详细描述本申请的实施例，所述实施例的示例在附图中示出，其中自始至终相同或类似的标号表示相同或类似的元件或具有相同或类似功能的元件。下面通过参考附图描述的实施例是示例性的，旨在用于解释本申请，而不能理解为对本申请的限制。
下面参考附图描述本申请实施例的超声传感器像素电路及其驱动方法以及显示面板。
图1为根据本申请实施例的超声传感器像素电路的方框示意图。如图1所示，本申请实施例的超声传感器像素电路包括检测模块10和输出模块20。
其中，检测模块10的第一端与超声波传感单元30相连，检测模块10的第二端与第一信号端Vbias1相连，检测模块10用于在第一信号端Vbias1的控制下根据超声波传感单元30输出的电信号生成检测电压，其中，电信号根据超声波传感单元30接收到的经手指反馈的超声波信号生成。
需说明的是，如图4所示，超声波传感单元30可采用压电三明治结构，例如，超声波传感单元30可包括压电组件PVDF、第一电极(或称阴极)TX和第二电极(或称阳极)RX，压电组件PVDF设置在第一电极TX与第二电极RX之间。在进行超声波指纹识别时，可给第一电极TX施加正弦波信号例如高压正弦波信号，同时给第二电极RX施加固定电压，则压电组件PVDF由于受到电压激发产生逆压电效应，向外发射超声波，在发射波接 触到物体例如手指时发生反射，由于手指指纹有谷脊之分，所以回波的震动强度有差异，此时，停止给第一电极TX施加高压正弦波信号，而变为施加固定电压，压电组件PVDF受到经手指反馈的回波的影响，因正压电效应，在第二电极RX上产生交流电信号，通过对该电信号的幅值进行测量即可确定手指的谷脊位置，进而实现超声波指纹识别。
应理解，可由P×Q个超声波传感单元30构造超声波传感结构，即超声波传感结构具有P行Q列超声波传感单元30，如图2-4所示，P行Q列超声波传感单元30中的压电组件PVDF可形成超声波传感结构的压电层301、第一电极TX可形成超声波传感结构的TX层302、且第二电极RX可形成超声波传感结构的RX层303，其中，压电层301位于TX层302和RX层303之间，即TX层302和RX层303分别设置在压电层301的两侧。
超声波传感结构可与显示面板例如OLED(Organic Light Emitting Display，有机发光显示器)显示面板相结合，作为一个示例，可采用如图2所示的集成度较高的层叠结构，具体为，将超声波传感结构以及超声传感器像素电路添加到显示模组中，也就是说，超声传感器像素电路以及超声波传感结构的RX层303可集成设置在显示模组的像素电路层(即Pixel array层)中，即图2中的Pixel array层既可充当显示所用的像素电路层，也具有超声波指纹识别所用的超声传感器像素电路，而超声波传感结构的压电层301和TX层302可设置在Pixel array层的下方。作为另一个示例，也可采用如图3所示的集成度降低的结构，具体为，将超声波传感结构以及超声传感器像素电路置于显示模组的下方，例如，将超声波传感结构以及超声传感器像素电路以外挂的方式设置在显示模组的下方，也就是说，显示像素电路设置在Pixel array层，即图3中的Pixel array层充当显示所用的像素电路层，而超声传感器像素电路以及超声波传感结构的RX层303独立地设置在Pixel array1层，即图3中的Pixel array1层充当超声波指纹识别像素电路层，超声波传感结构的压电层301和TX层302可设置在Pixel array1层的上方。
还需说明的是，超声波传感单元30输出的电信号可为正弦波电信号。
如图1所示，输出模块20的第一端与检测模块10的第三端相连，输出模块20的第二端与读取线RL相连，输出模块20用于根据检测电压生成输出信号，并将输出信号提供至读取线RL。
读取线RL还与外部检测电路相连，输出信号可通过读取线RL发送到外部检测电路，外部检测电路可根据接收到的输出信号来确定手指指纹的谷部或脊部。
需要说明的是，输出信号可指示经手指反射后入射到超声波传感单元30的超声波的强度和量值。
可理解，在第一信号端Vbias1的控制下，检测模块10根据超声波传感单元30输出的电信号例如正弦波电信号生成检测电压，然后输出模块20根据检测电压生成输出信号，并 将输出信号提供至读取线RL，以读取输出信号，由此，通过对经手指反馈的超声波信号的峰峰值进行检测，可实现高精度的超声波指纹识别。
具体而言，对前述超声传感器像素电路的输出信号的检测主要包括两个检测阶段：
在第一检测阶段，根据超声波传感单元30输出的电信号生成检测电压，其中，电信号根据超声波传感单元30接收到的经手指反馈的超声波信号生成。
在第二检测阶段，根据检测电压生成输出信号，并将输出信号提供至读取线RL。
也就是说，在第一检测阶段，在第一信号端Vbias1的控制下，检测模块10根据超声波传感单元30输出的电信号例如正弦波信号生成检测电压，然后，在第二检测阶段，输出模块20根据检测模块10生成的检测电压生成输出信号，并将输出信号提供至读取线RL，由此，可实现高精度的超声波指纹识别。
具体地，根据本申请的一个实施例，如图5-6所示，检测模块10包括：上拉单元101和电位保存单元102，上拉单元101与超声波传感单元30和第一信号端Vbias1相连，上拉单元101用于在第一信号端Vbias1的控制下将超声波传感单元30输出的电信号叠加到第二电位之上，以使电信号的波谷电位处于第二电位；电位保存单元102与上拉单元101相连，电位保存单元102用于根据叠加到第二电位之上的电信号生成检测电压，其中，检测电压为第二电位与电信号的峰峰值之和，第二电位高于第一电位。
需要说明的是，电信号的峰峰值可为电信号的波峰值减去电信号的波谷值所得到的差值，例如，超声波传感单元30输出的电信号可为正弦波电信号。
可理解，在第一检测阶段，上拉单元101在第一信号端Vbias1的控制下将超声波传感单元30输出的电信号即正弦波信号叠加到第二电位之上，进而，电位保存单元102根据叠加到第二电位之上的电信号生成检测电压，然后，在第二检测阶段，输出模块20根据电位保存单元102生成的检测电压生成输出信号，并将输出信号提供至读取线RL。
还需说明的是，在本实施例中，在将正弦波信号叠加到第二电位之上时，是将正弦波信号整体平移并使正弦波信号的波谷位于第二电位。
进一步地，根据本申请的一个实施例，如图5-6所示，超声传感器像素电路还包括超声波发射控制模块40，超声波发射控制模块40与超声波传感单元30和发射控制端IN相连，超声波发射控制模块40在发射控制端IN的控制下将第一电位施加到超声波传感单元30。
需要说明的是，第一电位为低电平电位，具体地，超声波发射控制模块40可与超声波传感单元30中的第二电极RX相连，超声波发射控制模块40在发射控制端IN的控制下将第一电位即低电平电位施加到超声波传感单元30中的第二电极RX。
可理解，在第一检测阶段之前，还包括超声波发射阶段，在超声波发射阶段，超声波 发射控制模块40在发射控制端IN的控制下将第一电位即低电平电位施加到超声波传感单元30，具体地，施加到超声波传感单元30中的第二电极RX，从而使得超声波传感单元30中的第二电极RX保持在固定电位。
更进一步地，根据本申请的一个实施例，如图5-6所示，超声传感器像素电路还包括复位模块50，复位模块50与检测模块10的第三端和复位端RESET相连，复位模块50在复位端RESET的控制下将检测模块10的第三端置为第二电位。
可理解，在第二检测阶段之后，还包括复位阶段，在复位阶段，复位模块50在复位端RESET的控制下将检测模块10的第三端置为第二电位以对检测模块10的第三端进行复位，其中，检测模块10的第三端用于提供检测电压。
下面结合图7和图8对本申请一个实施例的超声传感器像素电路的结构及原理进行说明。
根据本申请的一个实施例，如图7所示，上拉单元101包括第一二极管D1，第一二极管D1的阳极与第一信号端Vbias1相连，第一二极管D1的阴极与超声波传感单元30相连。
根据本申请的一个实施例，如图7所示，电位保存单元102包括第二二极管D2，第二二极管D2的阳极与第一二极管D1的阴极相连，第二二极管D2的阴极作为检测模块10的第三端。
根据本申请的一个实施例，如图7所示，超声波发射控制模块40包括：第一晶体管T1，第一晶体管T1的第一极与超声波传感单元30相连，第一晶体管T1的第二极与第一信号端Vbias1相连，第一晶体管T1的控制极与发射控制端IN相连。
需要说明的是，第一晶体管T1可为重置晶体管。
根据本申请的一个实施例，如图7所示，输出模块20包括驱动单元201，驱动单元201根据检测电压生成输出信号，其中，驱动单元201包括第二晶体管T2，第二晶体管T2的第一极与第一电源ELVSS相连，第二晶体管T2的第二极与读取线RL相连，第二晶体管T2的控制极与检测模块10的第三端相连。
可理解，驱动单元201可将生成的输出信号直接提供至读取线RL，实现超声波指纹识别。
需要说明的是，第二晶体管T2可为栅压控制型器件，具体类型以与读取线RL相连的外部检测电路的类型确定，如果外部检测电路为电流型检测电路，则第二晶体管T2为栅压控制电流型器件，如果外部检测电路为电压型检测电路，则第二晶体管T2为源极跟随器件。其中，以第二晶体管T2为栅压控制电流型器件为例，输出模块20根据检测电压生成的输出信号可为电流信号，该电流信号能够反映经手指反馈的回波信号的幅值的完整大小，实现对超声回波信号的完整幅值进行检测，进而能够提高超声波指纹识别的精度。
根据本申请的一个实施例，如图7所示，复位模块50包括：第四晶体管T4，第四晶体管T4的第一极与第二信号端Vbias2相连，第四晶体管T4的第二极与检测模块10的第三端相连，第四晶体管T4的控制极与复位端RESET相连。
需要说明的是，第四晶体管T4可为重置晶体管。
可理解，在复位阶段，在复位端RESET的控制下，第四晶体管T4开启，从而将第二信号端Vbias2输入的电压信号例如第二电位写入检测模块10的第三端，进而将检测模块10的第三端置为第二电位，以对检测模块10的第三端进行复位。
还需说明的是，第一晶体管T1、第二晶体管T2和第四晶体管T4可为NPN型晶体管，也可为PNP型晶体管，其中，NPN型晶体管即为N型晶体管，在高电平情况下导通，PNP型晶体管即为P型晶体管，在低电平情况下导通。本申请实施例的超声传感器像素电路以第一晶体管T1、第二晶体管T2和第四晶体管T4为NPN型晶体管为例进行说明。
另外，在本申请实施例中，在第一检测阶段之前还包括第三检测阶段，在第三检测阶段，在复位端RESET的控制下，第四晶体管T4开启，从而将第二信号端Vbias2输入的电压信号例如第二电位写入检测模块10的第三端，进而将检测模块10的第三端置为第二电位。
结合图8的时序图，图7实施例的工作原理如下：
其中，S1可为向超声波传感单元30中的第一电极(阴极)施加的驱动信号，IN1可为发射控制端IN的输入信号，RESET1可为复位端RESET的输入信号，Vbias11可为第一信号端Vbias1的输入信号，Vbias21可为第二信号端Vbias2的输入信号。
在超声波发射阶段t0，向超声波传感单元30中的第一电极TX施加的驱动信号S1为正弦波信号，同时发射控制端IN输入高电平信号，第一晶体管T1开启，并将第一信号端Vbias1输入的第一电位即低电平电位施加到超声波传感单元30，具体地，施加到超声波传感单元30中的第二电极RX，使得第二电极RX保持在固定电位，此时，超声波传感单元30中的压电组件由于受到电压激发产生逆压电效应，向外发射超声波。
在超声波发射阶段t0结束之后，停止向超声波传感单元30中的第一电极TX施加正弦波信号，即驱动信号S1变为固定电平，此时，在发射波接触到物体例如手指时发生反射，然后超声波传感单元30中的压电组件受到经手指反馈的回波的影响，因正压电效应，在第二电极RX上产生交流电信号，即在A点产生交流电信号。同时，发射控制端IN输入低电平信号，第一晶体管T1关闭，A点产生的交流电信号的波谷电位由第一信号端Vbias1的电位决定。
在第三检测阶段t3，第二信号端Vbias2的电位变为第二电位，需要说明的是，可在发射控制端IN变为低电平信号的时间达到第一预设时间后，将第二信号端Vbias2的电位变 为第二电位。其中，第二电位可为第二晶体管T2工作的静态工作点，复位端RESET输入高电平信号，第四晶体管T4开启，并将第二信号端Vbias2的输入信号即第二电位写入检测模块10的第三端即第二二极管D2的阴极，使得B点处于第二晶体管T2的静态工作点。之后将复位端RESET拉低，第四晶体管T4关闭。
在第一检测阶段t1，上拉第一信号端Vbias1的电位，需要说明的是，可在复位端RESET变为低电平信号的时间达到第二预设时间后，上拉第一信号端Vbias1的电位，使得第一信号端Vbias1的电位处于第二电位，此时，由于第一二极管D1的作用，A点处的正弦波电信号被叠加到第二电位之上，使得正弦波电信号的波谷电位处于第二电位，即A点处的电位被抬升至第二晶体管T2的静态工作点以上，之后再拉低第一信号端Vbias1的电位，以防止漏电，此时由于第二二极管D2的作用，B点可储存正弦波电信号的峰峰值。
应理解，基于二极管的特征，当二极管的阳极电位高于阴极电位时，二极管导通，使得二极管的阴极电位与阳极电位基本一致，而当二极管的阳极电位低于阴极电位时，二极管截止，二极管的阴极电位可保持不变，不会随阳极电位的降低而降低，由此，当A点处的正弦波电信号的波峰提供到第二二极管D2的阳极时，第二二极管D2的阴极电位被抬升到第二电位与A点处的正弦波电信号的峰峰值之和，即B点电位可被抬升到第二电位与A点处的正弦波电信号的峰峰值之和，随后B点电位保持在该电位不变，即为检测电压。
在第二检测阶段t2，第二晶体管T2根据B点处的检测电压生成输出信号即电流信号，并将输出信号即电流信号提供至读取线RL，进而外部检测电路可根据输出信号确定正弦波信号的峰峰值，进而确定手指指纹的谷部或脊部，从而实现高精度的超声波指纹识别。
在复位阶段t4，第二信号端Vbias2的输入信号变为第二电位，复位端RESET输入高电平信号，第四晶体管T4开启，并将第二信号端Vbias2的输入信号即第二电位写入检测模块10的第三端即第二二极管D2的阴极，以对B点进行复位。
下面结合图9和图10对本申请另一个实施例的超声传感器像素电路的结构及原理进行说明。
图9实施例的超声传感器像素电路的结构与图7实施例的区别在于，输出模块20除了包括驱动单元201之外，还包括读取单元202，如图9所示，输出模块20还包括连接在驱动单元201与读取线RL之间的读取单元202，读取单元202还与读取端RD相连，读取单元202用于在读取端RD的控制下将输出信号提供至读取线RL，其中，读取单元202包括第三晶体管T3，第三晶体管T3的第一极与第二晶体管T2的第二极相连，第三晶体管T3的第二级与读取线RL相连，第三晶体管T3的控制极与读取端RD相连。
可理解，读取单元202可在读取端RD的控制下将输出信号提供至读取线RL，实现超声波指纹识别。
需要说明的是，第三晶体管T3可为选通晶体管，以选通行读取。在本申请实施例中，采用行列读取模式，也就是说，当行选通打开时，每一列对应的读取线RL进行信号的读取，本行读取结束后，再开启下一行的第三晶体管T3，依次类推。
结合图10的时序图，图9实施例的工作原理如下：
其中，S1可为超声波传感单元30中的第一电极(阴极)施加的驱动信号，IN1可为发射控制端IN的输入信号，RD1可为读取端RD的输入信号，RESET1可为复位端RESET的输入信号，Vbias11可为第一信号端Vbias1的输入信号，Vbias21可为第二信号端Vbias2的输入信号。
在超声波发射阶段t0，向超声波传感单元30中的第一电极TX施加的驱动信号S1为正弦波信号，同时发射控制端IN输入高电平信号，第一晶体管T1开启，并将第一信号端Vbias1输入的第一电位即低电平电位施加到超声波传感单元30，具体地，施加到超声波传感单元30中的第二电极RX，使得第二电极RX保持在固定电位，此时，超声波传感单元30中的压电组件由于受到电压激发产生逆压电效应，向外发射超声波。
在超声波发射阶段t0结束之后，停止向超声波传感单元30中的第一电极TX施加正弦波信号，即驱动信号S1变为固定电平，此时，在发射波接触到物体例如手指时发生反射，然后超声波传感单元30中的压电组件受到经手指反馈的回波的影响，因正压电效应，在第二电极RX上产生交流电信号即在A点产生交流电信号。同时，发射控制端IN输入低电平信号，第一晶体管T1关闭，A点产生的交流电信号的波谷电位由第一信号端Vbias1的电位决定。
在第一检测阶段t1，延时预设时间后上拉第一信号端Vbias1的电位，使得第一信号端Vbias1的电位处于第二电位，此时，由于第一二极管D1的作用，A点处的正弦波电信号被叠加到第二电位之上，使得正弦波电信号的波谷电位处于第二电位，即A点处的电位被抬升至第二晶体管T2的静态工作点以上，其中，第二电位可为第二晶体管T2工作的静态工作点，之后再拉低第一信号端Vbias1的电位，以防止漏电，此时由于第二二极管D2的作用，B点可储存正弦波电信号的峰峰值。
应理解，基于二极管的特征，当二极管的阳极电位高于阴极电位时，二极管导通，使得二极管的阴极电位与阳极电位基本一致，而当二极管的阳极电位低于阴极电位时，二极管截止，二极管的阴极电位可保持不变，不会随阳极电位的降低而降低，由此，当A点处的正弦波电信号的波峰提供到第二二极管D2的阳极时，第二二极管D2的阴极电位被抬升到第二电位与A点处的正弦波电信号的峰峰值之和，即B点电位可被抬升到第二电位与A点处的正弦波电信号的峰峰值之和，随后B点电位保持在该电位不变，即为检测电压。
需要说明的是，由于超声波传感单元30设置在显示面板的内部，发射波在接触到手指 之前还会接触到其他物体例如显示屏幕等，进而超声波传感单元30中的压电组件在受到经手指反馈的回波的影响之前，还会受到经显示屏幕反馈的回波的影响，并因正压电效应，在第二电极RX上产生交流电信号，即在A点产生交流电信号，因此需要延时预设时间后上拉第一信号端Vbias1的电位，以确保此时A点处的交流电信号是根据经手指反馈的回波信号生成的，进而使得超声波指纹识别更加准确。
其中，预设时间可根据超声波传感单元30接收到的经手指反馈的回波信号的时间确定。
在第二检测阶段t2，第二晶体管T2根据B点处的检测电压生成输出信号即电流信号，读取端RD输入高电平信号，第三晶体管T3开启，并将输出信号即电流信号提供至读取线RL，进而外部检测电路可根据输出信号确定正弦波信号的峰峰值，进而确定手指指纹的谷部或脊部，从而实现高精度的超声波指纹识别。
在复位阶段t3，第二信号端Vbias2的输入信号变为第二电位，复位端RESET输入高电平信号，第四晶体管T4开启，并将第二信号端Vbias2的输入信号即第二电位写入检测模块10的第三端即第二二极管D2的阴极，以对B点进行复位。
综上，根据本申请实施例提出的超声传感器像素电路，检测模块在第一信号端的控制下根据超声波传感单元输出的电信号生成检测电压，然后输出模块根据检测电压生成输出信号，并将输出信号提供至读取线。由此，本申请实施例的超声传感器像素电路能够对超声波经手指反馈的回波信号的峰峰值进行检测，实现对超声回波信号的完整幅值进行检测，进而提高指纹识别的精度。
基于上述实施例的超声传感器像素电路，本申请实施例还提出了一种显示面板，包括前述的超声传感器像素电路。
根据本申请的一个实施例，多个超声传感器像素电路集成设置于显示面板的像素电路层中，或者，多个超声传感器像素电路设置于显示面板的像素电路层下方。
根据本申请实施例提出的显示面板，通过设置的超声传感器像素电路，能够对超声波经手指反馈的回波信号的峰峰值进行检测，实现对超声回波信号的完整幅值进行检测，进而提高指纹识别的精度。
基于上述实施例的超声传感器像素电路，本申请实施例还提出了一种超声传感器像素电路的驱动方法。
图11为根据本申请实施例的超声传感器像素电路的驱动方法的流程示意图，如图11所示，本申请实施例的超声传感器像素电路的驱动方法包括以下步骤：
S1，在第一检测阶段，根据超声波传感单元输出的电信号生成检测电压，其中，电信号根据超声波传感单元接收到的经手指反馈的超声波信号生成。
S2，在第二检测阶段，根据检测电压生成输出信号，并将输出信号提供至读取线。
根据本申请的一个实施例，在第一检测阶段之前，还包括：在超声波发射阶段，将第一电位施加到超声波传感单元；在第二检测阶段之后，还包括：在复位阶段，将检测模块的第三端置为第二电位，其中，检测模块的第三端用于提供检测电压。
根据本申请的一个实施例，在第一检测阶段之前，还包括：在第三检测阶段，将检测模块的第三端置为第二电位，其中，检测模块的第三端用于提供检测电压。
如上所述，与上述实施例的超声传感器像素电路相对应，本申请实施例的超声传感器像素电路的驱动方法也可为两种。
其中，如图12所示，与图7实施例相对应的超声传感器像素电路的驱动方法包括以下步骤：
S101，在超声波发射阶段，将第一电位施加到超声波传感单元。
S102，在第三检测阶段，将检测模块的第三端置为第二电位，其中，检测模块的第三端用于提供检测电压。
S103，在第一检测阶段，根据超声波传感单元输出的电信号生成检测电压，其中，电信号根据超声波传感单元接收到的经手指反馈的超声波信号生成。
S104，在第二检测阶段，根据检测电压生成输出信号，并将输出信号提供至读取线。
S105，在复位阶段，将检测模块的第三端置为第二电位，其中，检测模块的第三端用于提供检测电压。
如图13所示，与图9实施例相对应的超声传感器像素电路的驱动方法包括以下步骤：
S201，在超声波发射阶段，将第一电位施加到超声波传感单元。
S202，在第一检测阶段，根据超声波传感单元输出的电信号生成检测电压，其中，电信号根据超声波传感单元接收到的经手指反馈的超声波信号生成。
S203，在第二检测阶段，根据检测电压生成输出信号，并将输出信号提供至读取线。
S204，在复位阶段，将检测模块的第三端置为第二电位，其中，检测模块的第三端用于提供检测电压。
综上，根据本申请实施例提出的超声传感器像素电路的驱动方法，首先根据超声波传感单元输出的电信号生成检测电压，然后根据检测电压生成输出信号，并将输出信号提供至读取线。由此，本申请实施例的超声传感器像素电路的驱动方法能够对超声波经手指反馈的回波信号的峰峰值进行检测，实现对超声回波信号的完整幅值进行检测，进而提高指纹识别的精度。
在本说明书的描述中，参考术语“一个实施例”、“一些实施例”、“示例”、“具体示例”、或“一些示例”等的描述意指结合该实施例或示例描述的具体特征、结构、材料或者特点包含于本申请的至少一个实施例或示例中。在本说明书中，对上述术语的示意性表述不必须 针对的是相同的实施例或示例。而且，描述的具体特征、结构、材料或者特点可以在任一个或多个实施例或示例中以合适的方式结合。此外，在不相互矛盾的情况下，本领域的技术人员可以将本说明书中描述的不同实施例或示例以及不同实施例或示例的特征进行结合和组合。
此外，术语“第一”、“第二”仅用于描述目的，而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量。由此，限定有“第一”、“第二”的特征可以明示或者隐含地包括至少一个该特征。在本申请的描述中，“多个”的含义是至少两个，例如两个，三个等，除非另有明确具体的限定。
流程图中或在此以其他方式描述的任何过程或方法描述可以被理解为，表示包括一个或更多个用于实现定制逻辑功能或过程的步骤的可执行指令的代码的模块、片段或部分，并且本申请的优选实施方式的范围包括另外的实现，其中可以不按所示出或讨论的顺序，包括根据所涉及的功能按基本同时的方式或按相反的顺序，来执行功能，这应被本申请的实施例所属技术领域的技术人员所理解。
在流程图中表示或在此以其他方式描述的逻辑和/或步骤，例如，可以被认为是用于实现逻辑功能的可执行指令的定序列表，可以具体实现在任何计算机可读介质中，以供指令执行系统、装置或设备(如基于计算机的系统、包括处理器的系统或其他可以从指令执行系统、装置或设备取指令并执行指令的系统)使用，或结合这些指令执行系统、装置或设备而使用。就本说明书而言，"计算机可读介质"可以是任何可以包含、存储、通信、传播或传输程序以供指令执行系统、装置或设备或结合这些指令执行系统、装置或设备而使用的装置。计算机可读介质的更具体的示例(非穷尽性列表)包括以下：具有一个或多个布线的电连接部(电子装置)，便携式计算机盘盒(磁装置)，随机存取存储器(RAM)，只读存储器(ROM)，可擦除可编辑只读存储器(EPROM或闪速存储器)，光纤装置，以及便携式光盘只读存储器(CDROM)。另外，计算机可读介质甚至可以是可在其上打印所述程序的纸或其他合适的介质，因为可以例如通过对纸或其他介质进行光学扫描，接着进行编辑、解译或必要时以其他合适方式进行处理来以电子方式获得所述程序，然后将其存储在计算机存储器中。
应当理解，本申请的各部分可以用硬件、软件、固件或它们的组合来实现。在上述实施方式中，多个步骤或方法可以用存储在存储器中且由合适的指令执行系统执行的软件或固件来实现。如，如果用硬件来实现和在另一实施方式中一样，可用本领域公知的下列技术中的任一项或他们的组合来实现：具有用于对数据信号实现逻辑功能的逻辑门电路的离散逻辑电路，具有合适的组合逻辑门电路的专用集成电路，可编程门阵列(PGA)，现场可编程门阵列(FPGA)等。
本技术领域的普通技术人员可以理解实现上述实施例方法携带的全部或部分步骤是可以通过程序来指令相关的硬件完成，所述的程序可以存储于一种计算机可读存储介质中，该程序在执行时，包括方法实施例的步骤之一或其组合。
此外，在本申请各个实施例中的各功能单元可以集成在一个处理模块中，也可以是各个单元单独物理存在，也可以两个或两个以上单元集成在一个模块中。上述集成的模块既可以采用硬件的形式实现，也可以采用软件功能模块的形式实现。所述集成的模块如果以软件功能模块的形式实现并作为独立的产品销售或使用时，也可以存储在一个计算机可读取存储介质中。
上述提到的存储介质可以是只读存储器，磁盘或光盘等。尽管上面已经示出和描述了本申请的实施例，可以理解的是，上述实施例是示例性的，不能理解为对本申请的限制，本领域的普通技术人员在本申请的范围内可以对上述实施例进行变化、修改、替换和变型。

Claims (15)

  1. 一种超声传感器像素电路，其特征在于，包括：
    检测模块，所述检测模块的第一端与超声波传感单元相连，所述检测模块的第二端与第一信号端相连，所述检测模块用于在所述第一信号端的控制下根据所述超声波传感单元输出的电信号生成检测电压；
    输出模块，所述输出模块的第一端与所述检测模块的第三端相连，所述输出模块的第二端与读取线相连，所述输出模块用于根据所述检测电压生成输出信号，并将所述输出信号提供至所述读取线。
  2. 根据权利要求1所述的超声传感器像素电路，其特征在于，所述检测模块包括：
    上拉单元，所述上拉单元与所述超声波传感单元和所述第一信号端相连，所述上拉单元用于在所述第一信号端的控制下将所述超声波传感单元输出的电信号叠加到第二电位之上，以使所述电信号的波谷电位处于所述第二电位；
    电位保存单元，所述电位保存单元与所述上拉单元相连，所述电位保存单元用于根据叠加到第二电位之上的电信号生成所述检测电压，其中，所述检测电压为所述第二电位与电信号的峰峰值之和。
  3. 根据权利要求2所述的超声传感器像素电路，其特征在于，所述上拉单元包括第一二极管，所述第一二极管的阳极与所述第一信号端相连，所述第一二极管的阴极与所述超声波传感单元相连。
  4. 根据权利要求3所述的超声传感器像素电路，其特征在于，所述电位保存单元包括第二二极管，所述第二二极管的阳极与所述第一二极管的阴极相连，所述第二二极管的阴极作为所述检测模块的第三端。
  5. 根据权利要求1所述的超声传感器像素电路，其特征在于，还包括：
    超声波发射控制模块，所述超声波发射控制模块与所述超声波传感单元和发射控制端相连，所述超声波发射控制模块在所述发射控制端的控制下将第一电位施加到所述超声波传感单元。
  6. 根据权利要求1所述的超声传感器像素电路，其特征在于，还包括：
    复位模块，所述复位模块与所述检测模块的第三端和复位端相连，所述复位模块在所述复位端的控制下将所述检测模块的第三端置为第二电位。
  7. 根据权利要求5所述的超声传感器像素电路，其特征在于，所述超声波发射控制模块包括：
    第一晶体管，所述第一晶体管的第一极与所述超声波传感单元相连，所述第一晶体管 的第二极与所述第一信号端相连，所述第一晶体管的控制极与所述发射控制端相连。
  8. 根据权利要求1所述的超声传感器像素电路，其特征在于，所述输出模块包括驱动单元，所述驱动单元根据所述检测电压生成所述输出信号，其中，
    所述驱动单元包括第二晶体管，所述第二晶体管的第一极与第一电源相连，所述第二晶体管的第二极与所述读取线相连，所述第二晶体管的控制极与所述检测模块的第三端相连。
  9. 根据权利要求8所述的超声传感器像素电路，其特征在于，所述输出模块还包括连接在所述驱动单元与所述读取线之间的读取单元，所述读取单元还与读取端相连，所述读取单元用于在所述读取端的控制下将所述输出信号提供至所述读取线，其中，
    所述读取单元包括第三晶体管，所述第三晶体管的第一极与所述第二晶体管的第二极相连，所述第三晶体管的第二级与所述读取线相连，所述第三晶体管的控制极与读取端相连。
  10. 根据权利要求6所述的超声传感器像素电路，其特征在于，所述复位模块包括：
    第四晶体管，所述第四晶体管的第一极与第二信号端相连，所述第四晶体管的第二极与所述检测模块的第三端相连，所述第四晶体管的控制极与所述复位端相连。
  11. 一种显示面板，其特征在于，包括多个如权要求1-10中任一项所述的超声传感器像素电路。
  12. 根据权利要求11所述的显示面板，其特征在于，所述多个超声传感器像素电路集成设置于所述显示面板的像素电路层中，或者，所述多个超声传感器像素电路设置于所述显示面板的像素电路层下方。
  13. 一种超声传感器像素电路的驱动方法，其特征在于，包括以下步骤：
    在第一检测阶段，根据超声波传感单元输出的电信号生成检测电压；
    在第二检测阶段，根据所述检测电压生成输出信号，并将所述输出信号提供至读取线。
  14. 根据权利要求13所述的超声传感器像素电路的驱动方法，其特征在于，在所述第一检测阶段之前，还包括：
    在第三检测阶段，将检测模块的第三端置为第二电位，其中，所述检测模块的第三端用于提供所述检测电压。
  15. 根据权利要求13或14所述的超声传感器像素电路的驱动方法，其特征在于，
    在所述第一检测阶段之前，还包括：
    在超声波发射阶段，将第一电位施加到所述超声波传感单元；
    在所述第二检测阶段之后，还包括：
    在复位阶段，将检测模块的第三端置为第二电位，其中，所述检测模块的第三端用于提供所述检测电压。
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