CN110135348B

CN110135348B - Fingerprint detection circuit, driving method thereof, array substrate and display device

Info

Publication number: CN110135348B
Application number: CN201910408037.0A
Authority: CN
Inventors: 曹学友; 丁小梁; 刘飞腾; 王鹏鹏; 邓立凯; 王海生; 李亚鹏; 张平; 王文娟
Original assignee: BOE Technology Group Co Ltd
Current assignee: BOE Technology Group Co Ltd
Priority date: 2019-05-15
Filing date: 2019-05-15
Publication date: 2021-02-09
Anticipated expiration: 2039-05-15
Also published as: CN110135348A

Abstract

The application discloses a fingerprint detection circuit, a driving method thereof, an array substrate and a display device, and relates to the technical field of fingerprint detection. The fingerprint detection circuit may include a switch sub-circuit, a reset sub-circuit, an output sub-circuit, a photosensor, and an ultrasonic sensor. The sub-circuits can work in a matched mode under the control of the signal ends, so that the output sub-circuit can output fingerprint detection signals from the photoelectric sensor and can also output fingerprint detection signals from the ultrasonic sensor. Therefore, when the light intensity of the external environment light is large, the output sub-circuit can be controlled to output the fingerprint detection signal from the ultrasonic sensor, so that the detection accuracy of fingerprint detection is ensured. When the light intensity of the external environment light is small, the output sub-circuit can be controlled to output the fingerprint detection signal from the photoelectric sensor so as to reduce the power consumption of fingerprint detection.

Description

Fingerprint detection circuit, driving method thereof, array substrate and display device

Technical Field

The present disclosure relates to the field of fingerprint detection technologies, and in particular, to a fingerprint detection circuit, a driving method thereof, an array substrate, and a display device.

Background

In order to increase the screen ratio of the display device, the display device having a fingerprint detection function generally performs fingerprint detection using an optical fingerprint detection circuit, which may be disposed in a display area of the display device.

In the related art, the optical fingerprint detection circuit may include a photosensor. When a user touches a finger with a display screen of the display device, light emitted by a light-emitting element of the display device can be reflected by the finger of the user, the photoelectric sensor can detect the reflected light and generate an electric signal, and the electric signal is output to the fingerprint identification circuit through a reading line, so that the fingerprint identification circuit carries out fingerprint identification according to the received electric signal.

However, when the intensity of the external ambient light is large, the external ambient light may interfere with the light reflected by the finger of the user, and the detection accuracy of the optical fingerprint detection circuit is affected.

Disclosure of Invention

The application provides a fingerprint detection circuit, a driving method thereof, an array substrate and a display device, and can solve the problem that an optical fingerprint detection circuit in the related art is poor in detection accuracy. In one aspect, a fingerprint detection circuit is provided, the fingerprint detection circuit comprising: the device comprises an ultrasonic sensor, a photoelectric sensor, a switch sub-circuit, a reset sub-circuit and an output sub-circuit;

one end of the ultrasonic sensor is connected with a first power supply end, and the other end of the ultrasonic sensor is connected with the switch sub-circuit;

one end of the photoelectric sensor is connected with the first node, and the other end of the photoelectric sensor is connected with the second power supply end;

the switch sub-circuit is respectively connected with the first node and the first scanning signal end, and is used for responding to a first scanning signal from the first scanning signal end and controlling the connection and disconnection between the other end of the ultrasonic sensor and the first node;

the reset sub-circuit is respectively connected with the first node, the second scanning signal end and the reset signal end, and is used for responding to a second scanning signal from the second scanning signal end and controlling the connection and disconnection of the first node and the reset signal end;

the output sub-circuit is respectively connected with the first node, a third scanning signal end and an output end, and the output sub-circuit is used for responding to a third scanning signal from the third scanning signal end and the potential of the first node and outputting a fingerprint detection signal from the photoelectric sensor or a fingerprint detection signal from the ultrasonic sensor to the output end.

Optionally, the switch sub-circuit includes: a first transistor;

a gate of the first transistor is connected to the first scanning signal terminal, a first pole of the first transistor is connected to the other end of the ultrasonic sensor, and a second pole of the first transistor is connected to the first node;

wherein the first pole and the second pole are one of a source and a drain, respectively.

Optionally, the reset sub-circuit includes: a second transistor;

a gate of the second transistor is connected to the second scan signal terminal, a first pole of the second transistor is connected to the first node, and a second pole of the second transistor is connected to a reset signal terminal;

Optionally, the output sub-circuit includes: a third transistor, a fourth transistor, and a first amplifier;

a gate of the third transistor is connected to the third scan signal terminal, a first pole of the third transistor is connected to a second pole of the fourth transistor, and a second pole of the third transistor is connected to the first terminal of the first amplifier;

a gate of the fourth transistor is connected to the first node, and a first electrode of the fourth transistor is connected to a third power supply terminal;

the second end of the first amplifier is connected with a reference power supply end, and the third end of the first amplifier is connected with the output end.

Optionally, the output end includes: the first output end is used for connecting the ultrasonic fingerprint identification circuit, and the second output end is used for connecting the optical fingerprint identification circuit; the output sub-circuit is also respectively connected with the reset signal end and the reset end of the reset sub-circuit;

the output sub-circuit is used for outputting a fingerprint detection signal from the ultrasonic sensor to the first output end and outputting a fingerprint detection signal from the photoelectric sensor to the second output end;

the output sub-circuit is further configured to output the reset signal from the reset signal terminal to the reset terminal.

Optionally, the output sub-circuit includes: the transistor comprises a third transistor, a fourth transistor, a fifth transistor, a first amplifier, a second amplifier and a capacitor;

a gate of the fourth transistor is connected to a second pole of the fifth transistor, and a first pole of the fourth transistor is connected to a third power supply terminal;

a grid electrode of the fifth transistor is connected with a fourth scanning signal end, and a first electrode of the fifth transistor is connected with the first node;

the second end of the first amplifier is connected with a reference power supply end, and the third end of the first amplifier is connected with the first output end;

a first end of the second amplifier is connected with the reset end, a second end of the second amplifier is connected with the reset signal end, and a third end of the second amplifier is connected with the second output end;

one end of the capacitor is connected with the reset end, and the other end of the capacitor is connected with the third end of the second amplifier.

In another aspect, there is provided a driving method of a fingerprint detection circuit for driving the fingerprint detection circuit as described in the above aspect, the method comprising:

a first reset stage of supplying a driving signal to a first power supply terminal, supplying a first scanning signal of a first potential to a first scanning signal terminal, supplying a second scanning signal of the first potential to a second scanning signal terminal, and supplying a pulse signal to a second power supply terminal, the ultrasonic sensor generating an ultrasonic wave in response to the driving signal, the reset sub-circuit outputting a reset signal from the reset signal terminal to a first node in response to the second scanning signal, the photoelectric sensor being in a reverse bias state in response to the pulse signal;

a first output stage, providing a first scanning signal position of a first potential to the first scanning signal terminal, providing a third scanning signal of the first potential to a third scanning signal terminal, providing a second scanning signal of a second potential to the second scanning signal terminal, wherein the ultrasonic sensor responds to the received reflected ultrasonic wave, outputs a fingerprint detection signal to the first node through a switch sub-circuit, and the output sub-circuit responds to the third scanning signal, and outputs the fingerprint detection signal from the ultrasonic sensor to an output terminal;

a second reset phase, in which a power signal of a second potential is provided to the second power source terminal, a first scanning signal of the second potential is provided to the first scanning signal terminal, and a second scanning signal of the first potential is provided to the second scanning signal terminal, the switch sub-circuit controls the turn-off of the path between the ultrasonic sensor and the first node in response to the first scanning signal, the reset sub-circuit outputs a reset signal from the reset signal terminal to the first node in response to the second scanning signal, and the photoelectric sensor is in a reverse bias state in response to the power signal;

and in a second output stage, a power supply signal of a second potential is provided to the second power supply end, a first scanning signal of the second potential is provided to the first scanning signal end, the switch sub-circuit responds to the first scanning signal and controls the passage between the ultrasonic sensor and the first node to be closed, the photoelectric sensor responds to the received reflected light signal and outputs a fingerprint detection signal to the first node, and the output sub-circuit outputs the fingerprint detection signal from the photoelectric sensor to the output end.

in the first output stage, the output sub-circuit outputs a fingerprint detection signal from the ultrasonic sensor to the first output terminal in response to the third scan signal;

in the second output stage, a second scanning signal of the first potential is provided to the second scanning signal terminal, the reset sub-circuit is in a conducting state in response to the second scanning signal, and the output sub-circuit outputs the fingerprint detection signal from the photosensor to the second output terminal.

Optionally, before the first reset phase, the method further includes:

detecting the light intensity of the external environment light;

if the light intensity is greater than or equal to a light intensity threshold value, the first reset stage and the first output stage are sequentially executed;

and if the light intensity is smaller than the light intensity threshold value, the second reset stage and the second output stage are sequentially executed.

In still another aspect, an array substrate is provided, including: a substrate base plate, and a fingerprint detection circuit as described in the above aspect disposed on the substrate base plate.

In still another aspect, there is provided a display device including: the array substrate comprises an array substrate and a fingerprint identification circuit connected with a fingerprint detection circuit in the array substrate.

The beneficial effect that technical scheme that this application provided brought includes at least:

the application provides a fingerprint detection circuit, a driving method thereof, an array substrate and a display device. The fingerprint detection circuit may include a switch sub-circuit, a reset sub-circuit, an output sub-circuit, a photosensor, and an ultrasonic sensor. The sub-circuits can work in a matched mode under the control of the signal ends, so that the output sub-circuit can output fingerprint detection signals from the photoelectric sensor and can also output fingerprint detection signals from the ultrasonic sensor. Therefore, when the light intensity of the external environment light is large, the output sub-circuit can be controlled to output the fingerprint detection signal from the ultrasonic sensor, so that the detection accuracy of fingerprint detection is ensured. When the light intensity of the external environment light is small, the output sub-circuit can be controlled to output the fingerprint detection signal from the photoelectric sensor so as to reduce the power consumption of fingerprint detection.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a fingerprint detection circuit according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of another fingerprint detection circuit according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a fingerprint detection circuit according to another embodiment of the present invention;

fig. 4 is a flowchart of a driving method of a fingerprint detection circuit according to an embodiment of the present invention;

FIG. 5 is a flowchart of another driving method of a fingerprint detection circuit according to an embodiment of the present invention;

FIG. 6 is a timing diagram of signal terminals in a first reset phase and a first output phase according to an embodiment of the present invention;

FIG. 7 is a timing diagram of signal terminals in a second reset phase and a second output phase according to an embodiment of the present invention;

FIG. 8 is a timing diagram of signal terminals in a first reset phase and a first output phase according to another embodiment of the present invention;

FIG. 9 is a timing diagram of signal terminals in a second reset phase and a second output phase according to another embodiment of the present invention;

fig. 10 is a schematic structural diagram of an array substrate according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The transistors used in the embodiments of the present invention may be thin film transistors or field effect transistors or other devices having the same characteristics, and the transistors used in the embodiments of the present invention are mainly switching transistors according to the role in the circuit. Since the source and drain of the switching transistor used herein are symmetrical, the source and drain may be interchanged. In the embodiments of the present invention, the source is referred to as a first pole and the drain is referred to as a second pole, or the drain is referred to as a first pole and the source is referred to as a second pole. The form of the figure provides that the middle end of the transistor is a grid, the signal input end is a source, and the signal output end is a drain. In addition, the switching transistor used in the embodiment of the present invention may include any one of a P-type switching transistor that is turned on when the gate is at a low level and turned off when the gate is at a high level and an N-type switching transistor that is turned on when the gate is at a high level and turned off when the gate is at a low level. In addition, the plurality of signals in the embodiments of the present invention correspond to the first potential and the second potential. The first potential and the second potential represent only 2 state quantities of the potential of the signal, and do not represent that the first potential or the second potential has a specific value throughout the text.

In the related art, when the distance between the capacitive fingerprint detection circuit and the finger of the user is more than 300 μm (micrometers), the fingerprint of the user cannot be identified, and therefore, the capacitive fingerprint detection circuit needs to be arranged in a non-display area of the display device (for example, in an area where a home key of a mobile phone is located), which affects the screen occupation ratio. And the ultrasonic fingerprint detection circuit has higher driving voltage and larger power consumption. Therefore, the display device usually adopts the optical fingerprint detection circuit to perform fingerprint detection, and the optical fingerprint detection circuit can be arranged in the display area of the display screen, does not influence the screen occupation ratio, and has smaller power consumption. However, when the light intensity of the external environment light is large, the optical fingerprint detection circuit has a poor fingerprint detection effect.

Fig. 1 is a schematic structural diagram of a fingerprint detection circuit according to an embodiment of the present invention. The fingerprint detection circuit can solve the problem of poor fingerprint detection effect in the related technology. As can be seen with reference to fig. 1, the fingerprint detection circuit may comprise: an ultrasonic sensor D1, a photosensor D2, a switch sub-circuit 10, a reset sub-circuit 20, and an output sub-circuit 30.

As can be seen with reference to fig. 1, one end of the ultrasonic sensor D1 may be connected to the first power source terminal V1, and the other end of the ultrasonic sensor D1 may be connected to the switch sub-circuit 10. The first power source terminal V1 may provide a driving signal to the ultrasonic sensor D1, thereby driving the ultrasonic sensor D1 to operate.

One end of the photosensor D2 may be connected to the first node P1, and the other end of the photosensor D2 may be connected to the second power source terminal V2. The second power source terminal V2 can provide a power signal to the photo sensor D2, thereby controlling the operation state of the photo sensor D2.

For example, one end of the photosensor D2 connected to the first node P1 may be a cathode, and the other end connected to the second power source terminal V2 may be an anode. One end of the ultrasonic sensor D1 connected to the first power source terminal V1 may be a cathode, and the other end connected to the first node P1 may be an anode.

The switch sub-circuit 10 can be connected to the first node P1 and the first scan signal terminal S1, respectively, and the switch sub-circuit 10 can be used for controlling the connection and disconnection between the other end of the ultrasonic sensor D1 and the first node P1 in response to the first scan signal from the first scan signal terminal S1.

For example, the switch sub-circuit 10 can control the other end of the ultrasonic sensor D1 to be conducted with the first node P1 when the potential of the first scan signal provided by the first scan signal terminal S1 is an effective potential. The switch sub-circuit 10 can control the other end of the ultrasonic sensor D1 and the first node P1 to be turned off when the potential of the first scan signal provided by the first scan signal terminal S1 is the inactive potential.

The reset sub-circuit 20 can be respectively connected to the first node P1, the second scan signal terminal S2 and the reset signal terminal Vrst, and the reset sub-circuit 20 can be used for controlling the on/off of the first node P1 and the reset signal terminal Vrst in response to the second scan signal from the second scan signal terminal S2.

For example, the reset sub-circuit 20 can control the first node P1 and the reset signal terminal Vrst to be conducted when the potential of the second scan signal provided by the second scan signal terminal S2 is an effective potential. The reset sub-circuit 20 can control the path between the first node P1 and the reset signal terminal Vrst to be turned off when the potential of the second scan signal provided by the second scan signal terminal S2 is an inactive potential.

The output sub-circuit 30 may be connected to the first node P1, the third scan signal terminal S3, and the output terminal OUT, respectively, and the output sub-circuit 30 may be configured to output a fingerprint detection signal from the photosensor D2 or a fingerprint detection signal from the ultrasonic sensor D1 to the output terminal OUT in response to the third scan signal from the third scan signal terminal S3 and the potential of the first node P1.

Wherein, the output of output sub-circuit 30 can be connected with ultrasonic fingerprint identification circuit and optics fingerprint identification circuit respectively to can export the fingerprint detection signal from ultrasonic sensor to ultrasonic fingerprint identification circuit, export the fingerprint detection signal from photoelectric sensor to optics fingerprint identification circuit. So that each fingerprint recognition circuit can perform fingerprint recognition according to the received fingerprint detection signal.

For example, the output sub-circuit 30 may output the fingerprint detection signal from the photosensor D2 or the fingerprint detection signal from the ultrasonic sensor D1 to the output terminal OUT according to the potential of the third scan signal and the potential of the first node P1 when the potential of the third scan signal supplied from the third scan signal terminal S3 is the active potential.

In summary, the present invention provides a fingerprint detection circuit, which may include a switch sub-circuit, a reset sub-circuit, an output sub-circuit, a photo sensor, and an ultrasonic sensor. The sub-circuits can work in a matched mode under the control of the signal ends, so that the output sub-circuit can output fingerprint detection signals from the photoelectric sensor and can also output fingerprint detection signals from the ultrasonic sensor. Therefore, when the light intensity of the external environment light is large, the output sub-circuit can be controlled to output the fingerprint detection signal from the ultrasonic sensor, so that the detection accuracy of fingerprint detection is ensured. When the light intensity of the external environment light is small, the output sub-circuit can be controlled to output the fingerprint detection signal from the photoelectric sensor so as to reduce the power consumption of fingerprint detection.

Alternatively, the ultrasonic sensor D1 may include an anode, a piezoelectric film layer, and a cathode, which are sequentially stacked. Wherein the material from which the piezoelectric film layer is made may comprise a piezoelectric material. For example, the piezoelectric film layer may be made of polyvinylidene fluoride (PVDF).

The photosensor D2 may include an anode, a semiconductor film layer, and a cathode, which are sequentially stacked. The photo sensor D2 may be a Photodiode (PIN).

During the ultrasonic fingerprint recognition, the first power source terminal V1 may provide a driving signal, and the ultrasonic sensor D1 may generate an ultrasonic wave under the driving of the driving signal. After the user brings the finger into contact with the display screen of the display device, the ultrasonic sensor D1 may receive the reflected ultrasonic waves reflected by the user's finger. Since the intensities of the reflected ultrasonic waves reflected by the ridges and the valleys in the fingerprint of the finger are different, the ultrasonic sensor D1 may generate fingerprint detection signals (which may be electrical signals) of different intensities based on the detected ultrasonic waves of different intensities, and output the fingerprint detection signals to the ultrasonic fingerprint identification circuit through the output terminal OUT of the output sub-circuit 30. The ultrasonic fingerprint identification circuit can identify fingerprint lines according to the intensity of the fingerprint detection signal. The driving signal may be a square wave signal, a sine wave signal, a triangular wave signal, or the like.

During the optical fingerprint recognition, the second power supply terminal V2 may provide a power supply signal of a second potential, and the photosensor D2 may be in a reverse bias state by being driven by the power supply signal. After the user brings the finger into contact with the display screen of the display device, the photosensor D2 in the reverse bias state may receive the reflected light reflected by the user's finger and convert the optical signal into an electrical signal. Since the intensities of the reflected light reflected by the ridges and the valleys in the fingerprint of the user's finger are different, the photo sensor D2 may detect light signals of different intensities, thereby generating fingerprint detection signals (which may be electrical signals) of different intensities and outputting the fingerprint detection signals to the optical fingerprint recognition circuit through the output terminal OUT of the output sub circuit 30. The optical fingerprint identification circuit can identify fingerprint lines according to the intensity of the fingerprint detection signal.

Fig. 2 is a schematic structural diagram of another fingerprint detection circuit according to an embodiment of the present invention. As can be seen with reference to fig. 2, the switch sub-circuit 10 may comprise: the first transistor M1.

The gate of the first transistor M1 may be connected to the first scan signal terminal S1, the first pole of the first transistor M1 may be connected to the other terminal (e.g., anode) of the ultrasonic sensor D1, and the second pole of the first transistor M1 may be connected to the first node P1.

Alternatively, referring to fig. 2, the reset sub-circuit 20 may include: and a second transistor M2.

The gate of the second transistor M2 may be connected to the second scan signal terminal S2, the first pole of the second transistor M2 may be connected to the first node P1, and the second pole of the second transistor M2 may be connected to a reset signal terminal Vrst.

As an alternative implementation, the output sub-circuit 30 may be connected to only one output terminal OUT. Referring to fig. 2, the output sub-circuit 30 may include: a third transistor M3, a fourth transistor M4, and a first amplifier F1.

A gate of the third transistor M3 may be connected to the third scan signal terminal S3, a first pole of the third transistor M3 may be connected to a second pole of the fourth transistor M4, and a second pole of the third transistor M3 may be connected to a first terminal of the first amplifier F1.

The gate of the fourth transistor M4 may be connected to the first node P1, and the first pole of the first transistor M4 may be connected to the third power source terminal V3.

A second terminal of the first amplifier F1 may be connected to a reference power source terminal Vref, and a third terminal of the first amplifier F1 may be connected to an output terminal OUT. The first amplifier F1 can amplify the fingerprint detection signal transmitted from the first node P1 and transmit the amplified fingerprint detection signal to the fingerprint identification circuit, so as to ensure that the fingerprint identification circuit can effectively identify the fingerprint detection signal.

Fig. 3 is a schematic structural diagram of another fingerprint detection circuit according to an embodiment of the present invention. As can be seen with reference to fig. 3, as another alternative implementation, the output terminal to which the output sub-circuit 30 is connected may include: a first output OUT1 for connection to an ultrasonic fingerprinting circuit and a second output OUT2 for connection to an optical fingerprinting circuit. The output sub-circuit 30 may also be connected to the reset signal terminal Vrst and the reset terminal Va of the reset sub-circuit 20, respectively. That is, the reset sub-circuit 20 may be connected to the reset signal terminal Vrst through the output sub-circuit 30.

The output sub-circuit 30 may be used to output the fingerprint detection signal from the ultrasonic sensor D1 to the first output terminal OUT1 and the fingerprint detection signal from the photosensor D2 to the second output terminal OUT 2.

The output sub-circuit 30 may be further configured to output a reset signal from the reset signal terminal Vrst to the reset terminal Va.

Referring to fig. 3, in this implementation, the output sub-circuit 30 may include: a third transistor M3, a fourth transistor M4, a fifth transistor M5, a first amplifier F1, a second amplifier F2 and a capacitor C.

A gate of the fourth transistor M4 may be connected to the second pole of the fifth transistor M5, and a first pole of the fourth transistor M4 may be connected to the third power source terminal V3.

The gate of the fifth transistor M5 may be connected to the fourth scan signal terminal S4, and the first pole of the fifth transistor M5 may be connected to the first node P1.

A second terminal of the first amplifier F2 may be connected to a reference power source terminal Vref, and a third terminal of the first amplifier F1 may be connected to the first output terminal OUT 1. The first amplifier F1 can amplify the fingerprint detection signal transmitted from the first node P1 and transmit the amplified fingerprint detection signal to the ultrasonic fingerprint identification circuit through the first output terminal OUT1, so as to ensure that the ultrasonic fingerprint identification circuit can effectively identify the fingerprint detection signal.

A first terminal of the second amplifier F2 may be connected to the reset terminal Va, a second terminal of the second amplifier F2 may be connected to the reset signal terminal Vrst, and a third terminal of the second amplifier F2 may be connected to the second output terminal OUT 2. The second amplifier F2 can amplify the fingerprint detection signal transmitted from the first node P1 and transmit the amplified fingerprint detection signal to the optical fingerprint identification circuit through the second output terminal OUT2, so as to ensure that the optical fingerprint identification circuit can effectively identify the fingerprint detection signal.

One end of the capacitor C may be connected to the reset terminal Va, and the other end of the capacitor C may be connected to the third terminal of the second amplifier F2.

When the reset terminal Va of the reset sub-circuit 20 has no signal written therein, the potential of the first terminal of the second operational amplifier F2 may be equal to the potential of the second terminal of the second operational amplifier F2 according to the virtual short break principle of the second amplifier F2. That is, the potential of the reset terminal Va may be equal to the potential of the reset signal terminal Vrst. So that the reset sub-circuit 20 can output the reset signal of the reset signal terminal Vrst to the first node P1 in response to the second scan signal when the second scan signal terminal S2 outputs the second scan signal of the first potential, thereby implementing the reset of the first node P1.

For example, in the implementation shown in fig. 2, since the fifth transistor M5 may not be required to be provided, the gate of the fourth transistor M4 may be directly connected to the first node P1. In the implementation shown in fig. 3, the gate of the fourth transistor M4 may be connected to the first node P1 through the fifth transistor M5. That is, the gate of the fourth transistor M4 may be connected to the second pole of the fifth transistor M5.

In the embodiment of the invention, the gate of the fourth transistor M4 may have a potential equal to the potential of the first node P1, the fourth transistor M4 may be turned on when the potential of the first node P1 is an active potential, and the fourth transistor M4 may be turned off when the potential of the first node P1 is an inactive potential.

In summary, the present invention provides a fingerprint detection circuit, which may include a switch sub-circuit, a reset sub-circuit, an output sub-circuit, a photo sensor, and an ultrasonic sensor. The sub-circuits can work in a matched mode under the control of the signal ends, so that the output sub-circuit can output fingerprint detection signals from the photoelectric sensor and can also output fingerprint detection signals from the ultrasonic sensor. Therefore, when the light intensity of the external environment light is large, the output sub-circuit can be controlled to output the fingerprint detection signal from the ultrasonic sensor, so that the detection precision of fingerprint detection is ensured. When the light intensity of the external environment light is small, the output sub-circuit can be controlled to output the fingerprint detection signal from the photoelectric sensor so as to reduce the power consumption of fingerprint detection.

Fig. 4 is a flowchart of a driving method of a fingerprint detection circuit according to an embodiment of the present invention, which can be used to drive the fingerprint detection circuit according to the above-mentioned embodiment, and can be applied to a driving device of the fingerprint detection circuit. As shown in fig. 4, the method may include:

step 101, a first reset phase, providing a driving signal to a first power end, providing a first scanning signal of a first potential to a first scanning signal end, providing a second scanning signal of the first potential to a second scanning signal end, and providing a pulse signal to a second power end, wherein the ultrasonic sensor generates ultrasonic waves in response to the driving signal, the reset sub-circuit outputs a reset signal from the reset signal end to a first node in response to the second scanning signal, and the photoelectric sensor is in a reverse bias state in response to the pulse signal.

102, in a first output stage, providing a first scanning signal of a first potential to a first scanning signal terminal, providing a third scanning signal of the first potential to a third scanning signal terminal, providing a second scanning signal of a second potential to a second scanning signal terminal, outputting a fingerprint detection signal to the first node through a switch sub-circuit by the ultrasonic sensor in response to the received reflected ultrasonic wave, and outputting a fingerprint detection signal from the ultrasonic sensor to an output terminal by an output sub-circuit in response to the third scanning signal.

Step 103, a second reset phase, in which a power signal of a second potential is provided to a second power source terminal, a first scan signal of the second potential is provided to the first scan signal terminal, a second scan signal of the first potential is provided to the second scan signal terminal, the switch sub-circuit controls the turn-off of the path between the ultrasonic sensor and the first node in response to the first scan signal, the reset sub-circuit outputs a reset signal from the reset signal terminal to the first node in response to the second scan signal, and the photoelectric sensor is in a reverse bias state in response to the power signal.

And 104, in a second output stage, providing a power supply signal of a second potential to the second power supply end, providing a first scanning signal of the second potential to the first scanning signal end, controlling a path between the ultrasonic sensor and the first node to be closed by the switch sub-circuit in response to the first scanning signal, outputting a fingerprint detection signal to the first node by the photoelectric sensor in response to the received reflected light signal, and outputting the fingerprint detection signal from the photoelectric sensor to the output end by the output sub-circuit.

In summary, the present invention provides a driving method of a fingerprint detection circuit. Each sub-circuit in the fingerprint detection circuit can work in a matched mode under the control of the signal end, so that the output sub-circuit can output fingerprint detection signals from the ultrasonic sensor and can also output fingerprint detection signals from the photoelectric sensor. Therefore, when the light intensity of the external environment light is large, the output sub-circuit can be controlled to output the fingerprint detection signal from the ultrasonic sensor, so that the detection accuracy of fingerprint detection is ensured. When the light intensity of the external environment light is small, the output sub-circuit can be controlled to output the fingerprint detection signal from the photoelectric sensor so as to reduce the power consumption of fingerprint detection.

Alternatively, as can be seen with reference to fig. 3, the output terminal OUT to which the output sub-circuit 30 is connected may include: a first output OUT1 for connection to an ultrasonic fingerprinting circuit and a second output OUT2 for connection to an optical fingerprinting circuit. The output sub-circuit 30 may also be connected to a reset signal terminal Vrst and a reset terminal Va of the reset sub-circuit 20, respectively.

Accordingly, in the first output stage shown in the above step 102, the output sub-circuit may output the fingerprint detection signal from the ultrasonic sensor to the first output terminal OUT1 in response to the third scan signal.

In the second output phase shown in the above step 102, the second scan signal of the first potential is provided to the second scan signal terminal, the reset sub-circuit may be in a conducting state in response to the second scan signal, and the output sub-circuit may further output the signal from the first node P1, i.e., the fingerprint detection signal from the photosensor, to the second output terminal OUT 2.

Fig. 5 is a flowchart of another driving method for a fingerprint detection circuit according to an embodiment of the present invention, which can be used to drive the fingerprint detection circuit according to the above-mentioned embodiment, and can be applied to a driving device for a fingerprint detection circuit. As can be seen with reference to fig. 5, in this embodiment, before the first reset phase, the method may further include:

step 105, detecting whether the light intensity of the external environment light is larger than or equal to a light intensity threshold value.

In an embodiment of the present invention, the driving device of the fingerprint detection circuit may include a light intensity sensor, and the light intensity sensor may be configured to detect the light intensity of the external environment light. Further, the driving device may be stored with a light intensity threshold value in advance. After the driving device detects the light intensity of the external environment light through the light intensity sensor, the light intensity can be compared with a pre-stored light intensity threshold value. If the detected light intensity of the external environment light is greater than or equal to the light intensity threshold, it can be determined that the external environment light has a large influence on the detection accuracy of the photoelectric sensor, and therefore, the

steps

101 and 102 can be sequentially executed, that is, the fingerprint detection circuit can be instructed to detect the fingerprint signal through the ultrasonic sensor, so as to ensure the detection accuracy of the fingerprint detection. If the detected light intensity of the external environment light is smaller than the light intensity threshold, it can be determined that the influence of the external environment light on the detection precision of the photoelectric sensor is small, and then step 103 and step 104 can be sequentially executed, that is, the fingerprint detection circuit can be instructed to detect the fingerprint signal through the photoelectric sensor, so as to reduce the power consumption of fingerprint detection.

Taking the fingerprint detection circuit shown in fig. 2 as an example, and taking the transistors in the fingerprint detection circuit as N-type transistors, the first potential as an active potential, the second potential as an inactive potential, and the active potential being a high potential relative to the inactive potential as an example, the driving principle of the fingerprint detection circuit provided by the embodiment of the present invention is described.

Fig. 6 is a timing diagram of signal terminals in a first reset phase and a first output phase according to an embodiment of the present invention. As shown in fig. 6, the first reset phase T1 may include a first reset sub-phase T11 and a second reset sub-phase T12.

In the first reset sub-phase T11, the driving device provides the first scanning signal terminal S1 with the first potential and the second scanning signal terminal S2 with the second potential, provides the third scanning signal terminal S3 with the second potential, and provides the driving signal to the first power terminal V1. The first transistor M1 is turned on by the first scan signal, the second transistor M2 is turned on by the second scan signal, and the third transistor M3 is turned off by the third scan signal. The reset signal terminal Vrst may output a reset signal to the first node P1 through the second transistor M2, thereby resetting the first node P1. Meanwhile, the ultrasonic sensor D1 may generate ultrasonic waves in response to the driving signal.

In the second reset sub-phase T12, the driving device maintains the first potential for the first scan signal supplied to the first scan signal terminal S1, maintains the second potential for the third scan signal supplied to the third scan signal terminal S3, jumps to the second potential for the second scan signal supplied to the second scan signal terminal S2, and supplies the pulse signal to the second power source terminal V2. The first transistor M1 is maintained in an on state by being driven by the first scan signal, the second transistor M2 is turned off by being controlled by the second scan signal, and the third transistor M3 is maintained in an off state by being controlled by the third scan signal. The photo sensor D2 is turned on when the pulse signal is at a high level, so that the potential of the first node P1 is raised to the high level of the pulse signal. After the pulse signal jumps from a high potential to a low potential, the photosensor D2 is in a reverse bias state. Since the first transistor M1 is in an on state in this second reset sub-phase T12, the potential of the other end (i.e., the anode) of the ultrasonic sensor D1 is also raised to the same potential as the potential of the first node P1.

Optionally, in the embodiment of the present invention, the potential of the reset signal may be 1 volt (V), the range of the first potential of each scan signal may be 5V to 20V, and the range of the second potential may be-20V to-5V. The driving signal provided by the first power source terminal V1 may be a square wave signal, the low potential of the square wave signal may be 0V, and the high potential of the square wave signal may range from 5V to 20V. The first power source terminal V1 may supply a power source signal having a potential of 0V. The potential of the power supply signal supplied from the second power supply terminal V2 may be 1V. The high potential of the pulse signal provided by the second power source terminal V2 may range from 10V to 40V, and the low potential may be 1V.

In the first output phase T2, the driving device provides the first scan signal to the first scan signal terminal S1 and the third scan signal to the third scan signal terminal S3 at the first potential, and the second scan signal to the second scan signal terminal S2 at the second potential. The first transistor M1 is kept in an on state by being driven by the first scan signal, the second transistor M2 is kept in an off state by being controlled by the second scan signal, and the third transistor M3 is turned on by being driven by the third scan signal. At this time, the ultrasonic sensor D1 may start oscillating in response to the received reflected ultrasonic waves and output a fingerprint detection signal to the first node P1 through the first transistor M1, i.e., the ultrasonic sensor D1 may output a fingerprint detection signal to the first node P1. Then, the third transistor M3 may further transmit the fingerprint detection signal to the first amplifier F1, and the first amplifier F1 amplifies the fingerprint detection signal and transmits the amplified fingerprint detection signal to the ultrasonic fingerprint identification circuit through the output terminal OUT.

For example, in the structure shown in fig. 2, the fourth transistor M4 is turned on by the driving of the first node P1, and may transmit the fingerprint detection signal to the third transistor M3 by the driving of the third power source terminal V3, and the third transistor M3 may further transmit the fingerprint detection signal to the first amplifier F1, and the first amplifier F1 amplifies the fingerprint detection signal and outputs the fingerprint detection signal from the ultrasonic sensor D1 to the output terminal OUT. The intensity of the fingerprint detection signal received by the first pole of the third transistor M3 can be positively correlated to the intensity of the fingerprint detection signal received by the gate of the fourth transistor M4.

Since the potential of the other end of the ultrasonic sensor D1 connected to the first node P1 is raised to a potential equal to the high potential of the pulse signal in the first reset period T1, the ultrasonic sensor D1 can oscillate on the basis of the high potential of the pulse signal and output a fingerprint detection signal to the first node P1 on the basis of the high potential of the pulse signal in the first output period T2.

It should be noted that, referring to fig. 6, between the first reset phase T1 and the first output phase T2, there may be further included: a first integration phase T3. In this first integration phase T3, the driving means supplies the same potential to the respective signal terminals as at the end of the first reset phase T1. That is, the potential of the first scan signal supplied to the first scan signal terminal S1 is the first potential, the potential of the second scan signal supplied to the second scan signal terminal, and the potential of the third scan signal supplied to the third scan signal terminal S3 are the second potentials. The first transistor M1 maintains an on state under the driving of the first scan signal, the second transistor M2 maintains an off state under the control of the second scan signal, and the third transistor M3 maintains an off state under the control of the third scan signal. The ultrasonic sensor D1 generates a fingerprint detection signal in response to the received reflected ultrasonic waves. In the first integration period T3, the charges of the fingerprint detection signal are accumulated at the first node P1, thereby adjusting the potential of the first node P1.

Fig. 7 is a timing diagram of signal terminals in a second reset phase and a second output phase according to an embodiment of the present invention. Referring to fig. 7, in the second reset period T4, the potential of the first scan signal provided by the driving device to the first scan signal terminal S1 is the second potential. The potential of the second scan signal supplied to the second scan signal terminal S2 and the potential of the third scan signal supplied to the third scan signal terminal S3 may both be the first potential. The potential of the power supply signal supplied to the first power source terminal V1 and the potential of the power supply signal supplied to the second power source terminal V2 are both the second potential.

The second transistor M2 is turned on by the driving of the second scan signal, the third transistor M3 is turned on by the driving of the third scan signal, and the first transistor M1 is turned off by the control of the first scan signal. The reset signal terminal Vrst may output a reset signal to the first node P1 through the second transistor M2, thereby resetting the first node P1. The potential of the reset signal is higher than the potential of the power signal provided from the second power source terminal V2, so that the photosensor D2 can be in a reverse bias state.

Also, in the second reset phase T4, since the third transistor M3 is turned on, the potential of the first node P1 may be output to the output terminal OUT. That is, the optical fingerprinting circuit may pick up the potential after the first node P1 is reset.

In the second output phase T5, the driving device provides the first scanning signal to the first scanning signal terminal S1 and the second scanning signal to the second scanning signal terminal S2 at the second voltage level. The potential of the third scan signal supplied to the third scan signal terminal S3 is the first potential. The third transistor M3 is turned on by the driving of the third scan signal, the first transistor M1 maintains an off state under the control of the first scan signal, and the second transistor M2 maintains an off state under the control of the second scan signal. The photo sensor D2 can convert the received reflected light signal into a fingerprint detection signal in a reverse bias state, and output it to the first node P1. Since the third transistor M3 is in an on state, the fingerprint detection signal from the photosensor D2 can be output to the output terminal OUT. The optical fingerprint identification circuit may compare the fingerprint detection signal with the collected potential of the first node P1 after reset in the second reset period T4 to identify fingerprint lines.

Alternatively, the potential of the power supply signal supplied from the second power supply terminal V2 may range from-10V to-2V in the second reset period T4 and the second output period T5.

In the second reset phase T4 and the second output phase T5, since the power supply signal supplied from the first power supply terminal V1 is at the second potential, the operation of the ultrasonic sensor D1 is stopped, so that the interference of the ultrasonic sensor D1 on the fingerprint detection signal generated by the photoelectric sensor D2 can be avoided.

It should be further noted that, referring to fig. 7, between the second reset phase T4 and the second output phase T5, there may be further included: a second integration phase T6. In the second integration period T6, the potential of the first scan signal supplied to the first scan signal terminal S1, the potential of the second scan signal supplied to the second scan signal terminal S3, and the potential of the third scan signal supplied to the third scan signal terminal S3 may all be the second potential. The first transistor M1, the second transistor M2, and the third transistor M3 are all turned off. The photosensor D2 generates a fingerprint detection signal in response to the received reflected light signal. In the second integration period T6, the charge of the fingerprint detection signal is accumulated at the first node P1, thereby adjusting the potential of the first node P1.

It should be noted that, in the first reset phase T1, the first output phase T2, the first integration phase T3, the second reset phase T4, the second output phase T5 and the second integration phase T6, the third power supply terminal V3 may provide a bias power supply signal to the first electrode of the fourth transistor M4, and the potential of the bias power supply signal may range from 5V to 10V.

Taking the fingerprint detection circuit shown in fig. 3 as an example, and taking the transistor in the fingerprint detection circuit as an N-type transistor, the first potential as an active potential, the second potential as an inactive potential, and the active potential and the inactive potential as high potentials as an example, the driving principle of the fingerprint detection circuit provided by the embodiment of the present invention is described.

Fig. 8 is a timing diagram of signal terminals in the first reset phase and the first output phase according to another embodiment of the present invention. As shown in fig. 8, the first reset phase T1 may include a first reset sub-phase T11 and a second reset sub-phase T12.

In the first reset sub-phase T11, the driving device provides the first scan signal terminal S1 with the first scan signal, the second scan signal terminal S2 with the second scan signal, and the fourth scan signal terminal S4 with the fourth scan signal, and the third scan signal terminal S3 with the third scan signal is at the second potential. The first transistor M1 is turned on by the driving of the first scan signal, the second transistor M2 is turned on by the driving of the second scan signal, the fifth transistor M5 is turned on by the driving of the fourth scan signal, and the third transistor M3 is turned off by the control of the third scan signal. Since no signal is written to the reset terminal Va in the first reset sub-phase T11, the potential of the reset terminal Va may be equal to the potential of the reset signal terminal Vrst according to the virtual short break principle of the second amplifier F2. Since the second transistor M2 is turned on, the reset terminal Va can output a reset signal to the first node P1 through the second transistor M2, thereby resetting the first node P1. Meanwhile, the ultrasonic sensor D1 may generate ultrasonic waves in response to the driving signal.

In the second reset sub-phase T12, the driving device maintains the first potential of the first scan signal supplied to the first scan signal terminal S1 and the potential of the fourth scan signal supplied to the fourth scan signal terminal S4, jumps to the second potential of the second scan signal supplied to the second scan signal terminal S2, sets the potential of the third scan signal supplied to the third scan signal terminal S3 to the second potential, and supplies the pulse signal to the second power supply terminal V2. The first transistor M1 maintains an on state by being driven by the first scan signal, the fifth transistor M5 maintains an on state by being driven by the fourth scan signal, the second transistor M2 is turned off by being controlled by the second scan signal, and the third transistor M3 maintains an off state by being controlled by the third scan signal. The photo sensor D2 is turned on when the pulse signal is at a high level, so that the potential of the first node P1 is raised to the high level of the pulse signal. After the pulse signal jumps from a high potential to a low potential, the photosensor D2 is in a reverse bias state. Since the first transistor M1 and the fifth transistor M5 are both in the on state in the second reset sub-phase T12, the potential of the other end (i.e., the anode) of the ultrasonic sensor D1 and the potential of the gate of the fourth transistor M4 are both raised, for example, both can be raised to the same potential as the potential of the first node P1.

Optionally, in the embodiment of the present invention, the potential of the reset signal may be 1V, the range of the first potential of each scan signal may be 5V to 20V, and the range of the second potential may be-20V to-5V. The driving signal supplied from the first power source terminal V1 may be a square wave signal, the low potential of the square wave signal may be 0V, the high potential of the square wave signal may range from 5V to 20V, and the potential of the power source signal supplied from the first power source terminal V1 may be 0V. The potential of the power supply signal supplied from the second power supply terminal V2 may be 1V. The second power source terminal V2 may provide a pulse signal with a potential ranging from 10V to 40V, and a low potential of 1V.

In the first output stage T2, the driving device provides the first scan signal to the first scan signal terminal S1, the third scan signal to the third scan signal terminal S3, and the fourth scan signal to the fourth scan signal terminal S4 at the first potential, and the second scan signal to the second scan signal terminal S2 at the second potential. The first transistor M1 is maintained in an on state by the driving of the first scan signal, the third transistor M3 is turned on by the driving of the third scan signal, the fifth transistor M5 is maintained in an on state by the driving of the fourth scan signal, and the second transistor M2 is maintained in an off state by the control of the second scan signal. At this time, the ultrasonic sensor D1 may start oscillating in response to the received reflected ultrasonic waves and output a fingerprint detection signal to the first node P1 through the first transistor M1, i.e., the ultrasonic sensor D1 may output a fingerprint detection signal to the first node P1. The fifth transistor M5 in an on state may transmit a fingerprint detection signal to the gate of the fourth transistor M4, the fourth transistor M4 is in an on state, and may transmit a fingerprint detection signal to the third transistor M3 under the driving of the third power source terminal V3, the third transistor M3 transmits the fingerprint detection signal to the first amplifier F1, and the first amplifier F1 amplifies the fingerprint detection signal and outputs the fingerprint detection signal from the ultrasonic sensor D1 to the first output terminal OUT 1.

It should be noted that, referring to fig. 8, between the first reset phase T1 and the first output phase T2, there may be further included: a first integration phase T3. In this first integration phase T3, the driving means supplies the same potential to the respective signal terminals as at the end of the first reset phase T1. In the first integration period T3, the charges of the fingerprint detection signal are accumulated at the first node P1, thereby adjusting the potential of the first node P1.

Fig. 9 is a timing diagram of signal terminals in a second reset phase and a second output phase according to another embodiment of the present invention. Referring to fig. 9, in the second reset phase T4, the potential of the first scan signal supplied to the first scan signal terminal S1, the potential of the third scan signal supplied to the third scan signal terminal S3, and the potential of the fourth scan signal supplied to the fourth scan signal terminal S4 by the driving device are all the second potentials. The potential of the second scan signal supplied to the second scan signal terminal S2 is the first potential. The potential of the power supply signal supplied to the first power source terminal V1 and the potential of the power supply signal supplied to the second power source terminal V2 are both the second potential. At this time, the second transistor M2 is turned on by the driving of the second scan signal, the first transistor M1 is turned off by the control of the first scan signal, the third transistor M3 is turned off by the control of the third scan signal, and the fifth transistor M5 is turned off by the control of the fourth scan signal. Since the reset terminal Va has no signal written thereto in the second reset phase T4, the potential of the reset terminal Va may be equal to the potential of the reset signal terminal Vrst according to the virtual short break principle of the second amplifier F2. Since the second transistor M2 is turned on, the reset terminal Va can output a reset signal to the first node P1 through the second transistor M2, thereby resetting the first node P1. The potential of the reset signal is higher than the potential of the power signal provided from the second power source terminal V2, so that the photosensor D2 can be in a reverse bias state.

In the second output stage T5, the driving device supplies the potential of the first scan signal to the first scan signal terminal S1, the potential of the third scan signal to the third scan signal terminal S3, and the potential of the fourth scan signal to the fourth scan signal terminal S4 to the second potential. The potential of the second scan signal supplied to the second scan signal terminal S2 is the first potential. The second transistor M2 is turned on by the driving of the second scan signal, the first transistor M1 maintains an off state under the control of the first scan signal, the third transistor M3 maintains an off state under the control of the third scan signal, and the fifth transistor M5 maintains an off state under the control of the fourth scan signal. The photo sensor D2 can convert the received reflected light signal into a fingerprint detection signal in a reverse bias state, and output it to the first node P1. Since the second transistor M2 is in an on state, the second transistor M2 may transmit a fingerprint detection signal to the second amplifier F2, and the second amplifier F2 may amplify the fingerprint detection signal after receiving the fingerprint detection signal and output the fingerprint detection signal from the photosensor D2 to the second output terminal OUT 2.

Alternatively, the potential of the power supply signal supplied from the second power source terminal V2 may range from-10V to-2V in the second reset period T4 and the second output period T5.

In the second reset phase T4 and the second output phase T5, since the power signal supplied from the first power source terminal V1 is at the second potential, the operation of the ultrasonic sensor D1 is stopped to avoid the interference of the ultrasonic sensor D1 on the fingerprint detection signal generated by the photosensor D2.

It should be further noted that, referring to fig. 9, between the second reset phase T4 and the second output phase T5, there may be further included: a second integration phase T6. In the second integration period T6, the potential of the first scan signal supplied to the first scan signal terminal S1, the potential of the second scan signal supplied to the second scan signal terminal, the potential of the third scan signal supplied to the third scan signal terminal S3, and the potential of the fourth scan signal supplied to the fourth scan signal terminal S4 by the driving device may all be the second potential. The first transistor M1, the second transistor M2, the third transistor M3, and the fifth transistor M5 are all turned off. The photosensor D2 generates a fingerprint detection signal in response to the received reflected light signal. In the second integration period T6, the charge of the fingerprint detection signal is accumulated at the first node P1, thereby adjusting the potential of the first node P1.

In summary, the present invention provides a driving method of a fingerprint detection circuit. Each sub-circuit in the fingerprint detection circuit can work in a matched mode under the control of the signal end, so that the output sub-circuit can output fingerprint detection signals from the ultrasonic sensor and can also output fingerprint detection signals from the photoelectric sensor. Therefore, when the light intensity of the external environment light is larger, the output sub-circuit can be controlled to output the fingerprint detection signal from the ultrasonic sensor, so as to ensure the fingerprint detection effect. When the light intensity of the external environment light is small, the output sub-circuit can be controlled to output the fingerprint detection signal from the photoelectric sensor so as to reduce the power consumption of fingerprint detection.

The embodiment of the invention also provides a driving device of the fingerprint detection circuit, and the driving device can be used for realizing the driving method of the fingerprint detection circuit.

By way of example, the drive means may comprise: the light intensity detection circuit comprises a drive integrated circuit, a grid drive circuit, a light intensity sensor and a processor, wherein the drive integrated circuit is used for providing signals for a power supply signal end and providing reset signals for a reset signal end, the grid drive circuit is used for providing scanning signals for a scanning signal end, the light intensity sensor is used for detecting the light intensity of external environment light, and the processor is used for judging the size relation between the light intensity of the external environment light and a light intensity threshold value. That is, the processor may be configured to implement the method of step 105 in the embodiment shown in fig. 6.

Fig. 10 is a schematic structural diagram of an array substrate according to an embodiment of the present invention, and referring to fig. 10, the array substrate may include: a substrate 001, and a fingerprint detection circuit provided as the above embodiment provided on the substrate 001.

Referring to fig. 10, the fingerprint detection circuit is sequentially provided with a first electrode layer 002, a sensing material layer 003, a second electrode layer 004, and a transistor device layer 005 in a direction away from a substrate 001. Wherein the transistors in the fingerprint detection circuit may all be arranged in the transistor device layer 005. The sensing material layer 003 may include a piezoelectric film layer of the ultrasonic sensor D1 and a semiconductor film layer of the photoelectric sensor D2. The first electrode layer 001 may include therein a cathode of the ultrasonic sensor D1 and an anode of the photosensor D2. The second electrode layer 004 may include an anode of the ultrasonic sensor D1, and a cathode of the photosensor D2. By providing the cathode (also referred to as a lower electrode) of the ultrasonic sensor D1 and the anode of the photosensor D2 in the same layer and providing the anode (also referred to as an upper electrode) of the ultrasonic sensor D1 and the cathode of the photosensor D2 in the same layer, the manufacturing process of the array substrate can be simplified, which facilitates mass production of the array substrate.

As can also be seen with reference to fig. 10, the array substrate may include light emitting elements 008 of different colors, for example, a red light emitting element, a green light emitting element, and a blue light emitting element. The array substrate may further include a collimating film layer 006. The alignment film layer 006 may be located between the transistor layer 005 and the layer on which the light emitting element 007 is located. The alignment film 006 may include transparent regions 006a and opaque regions 006b arranged in a staggered manner.

This collimation rete 006 can be so that in the reverberation of being reflected by the user's finger, only the light of the regional 006a portion of printing opacity can see through, avoids the reverberation of the ridge and the valley reflection of finger to appear mixing the light phenomenon, influences the accuracy that the fingerprint detected.

As shown in fig. 10, the array substrate may further include a polarizer 008, a touch layer 009, and a cover plate 010. The polarizer 008 may be located on the side of the light emitting element 007 away from the substrate 001, the touch layer 009 may be located on the side of the polarizer 010 away from the substrate 001, and the cover plate 010 may be located on the side of the touch layer 009 away from the substrate 009.

The embodiment of the invention also provides a display device, which can comprise the array substrate provided by the embodiment. The display device may be: any product or component with a display function, such as a liquid crystal panel, electronic paper, an organic light-emitting diode (OLED) panel, an active-matrix organic light-emitting diode (AMOLED) panel, a mobile phone, a tablet computer, a television, a display, a notebook computer, and a digital photo frame.

It can be clearly understood by those skilled in the art that, for convenience and brevity of description, the specific working processes of the fingerprint detection circuit, the array substrate and the display device described above may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

The above description is only exemplary of the present application and should not be taken as limiting, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A fingerprint detection circuit, the fingerprint detection circuit comprising: the device comprises an ultrasonic sensor, a photoelectric sensor, a switch sub-circuit, a reset sub-circuit and an output sub-circuit;

the output sub-circuit is respectively connected with the first node, a third scanning signal terminal and an output terminal, and the output sub-circuit is used for responding to a third scanning signal from the third scanning signal terminal and the potential of the first node and outputting a fingerprint detection signal from the photoelectric sensor or a fingerprint detection signal from the ultrasonic sensor to the output terminal;

the fingerprint detection circuit further includes: a light intensity sensor for detecting a light intensity of external environment light;

if the light intensity of the external environment light detected by the light intensity sensor is greater than or equal to a light intensity threshold value, the output sub-circuit outputs a fingerprint detection signal from the ultrasonic sensor to the output end;

if the light intensity of the external environment light detected by the light intensity sensor is smaller than the light intensity threshold value, the output sub-circuit outputs the fingerprint detection signal from the photoelectric sensor to the output end.

2. The fingerprint detection circuit of claim 1, wherein the switch sub-circuit comprises: a first transistor;

3. The fingerprint detection circuit of claim 1, wherein the reset sub-circuit comprises: a second transistor;

4. The fingerprint detection circuit of any one of claims 1 to 3, wherein the output sub-circuit comprises: a third transistor, a fourth transistor, and a first amplifier;

5. The fingerprint detection circuit of any one of claims 1 to 3, wherein the output comprises: the first output end is used for connecting the ultrasonic fingerprint identification circuit, and the second output end is used for connecting the optical fingerprint identification circuit; the output sub-circuit is also respectively connected with the reset signal end and the reset end of the reset sub-circuit;

6. The fingerprint detection circuit of claim 5, wherein the output sub-circuit comprises: the transistor comprises a third transistor, a fourth transistor, a fifth transistor, a first amplifier, a second amplifier and a capacitor;

7. A method of driving a fingerprint detection circuit, the method being used to drive a fingerprint detection circuit according to any one of claims 1 to 6, the method comprising:

a second output stage for supplying a power supply signal of a second potential to the second power supply terminal and supplying a first scanning signal of the second potential to the first scanning signal terminal, the switch sub-circuit controlling the turn-off of the path between the ultrasonic sensor and the first node in response to the first scanning signal, the photoelectric sensor outputting a fingerprint detection signal to the first node in response to the received reflected light signal, and the output sub-circuit outputting a fingerprint detection signal from the photoelectric sensor to the output terminal;

prior to the first reset phase, the method further comprises:

detecting the light intensity of the external environment light;

8. The driving method of a fingerprint detection circuit according to claim 7, wherein the output terminal comprises: the first output end is used for connecting the ultrasonic fingerprint identification circuit, and the second output end is used for connecting the optical fingerprint identification circuit; the output sub-circuit is also respectively connected with the reset signal end and the reset end of the reset sub-circuit;

9. An array substrate, comprising: a substrate, and a fingerprint detection circuit as claimed in any one of claims 1 to 6 disposed on the substrate.

10. A display device, characterized in that the display device comprises: the array substrate of claim 9, and a fingerprint identification circuit connected to the fingerprint detection circuit in the array substrate.