CN108280432B - Fingerprint identification detection circuit, driving method thereof and display device - Google Patents
Fingerprint identification detection circuit, driving method thereof and display device Download PDFInfo
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- CN108280432B CN108280432B CN201810072280.5A CN201810072280A CN108280432B CN 108280432 B CN108280432 B CN 108280432B CN 201810072280 A CN201810072280 A CN 201810072280A CN 108280432 B CN108280432 B CN 108280432B
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- 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
- G06V40/1318—Sensors therefor using electro-optical elements or layers, e.g. electroluminescent sensing
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- 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
Abstract
The invention provides a fingerprint identification detection circuit, a driving method thereof and a display device, and belongs to the technical field of display. The fingerprint identification detection circuit of the invention comprises: the device comprises a reset unit, a photosensitive unit, a current generation unit, a switch unit and a reset voltage supply unit; the reset voltage supply unit is used for providing a first reset voltage for the reset unit in a reset stage and providing a second reset voltage for the reset unit in an integration stage so as to enable the reset unit to generate stable leakage current; the reset unit is used for resetting the potential of the G node through a first reset voltage under the control of a reset signal; the photosensitive unit is used for generating corresponding electric signals according to the optical signals sensed by the photosensitive unit; the current generation unit is used for generating corresponding leakage current according to the received electric signal; the switch unit is used for outputting the leakage current output by the current generation unit under the control of the scanning signal so as to identify the fingerprint information.
Description
Technical Field
The invention belongs to the technical field of display, and particularly relates to a fingerprint identification detection circuit, a driving method thereof and a display device.
Background
The prior fingerprint identification devices have the advantages and the disadvantages of capacitance, ultrasonic wave and optical, but have the common defect that the induction distance of the fingerprint identification device is short, the structure and the performance of the fingerprint identification device are seriously limited, and the wide application of the fingerprint identification device in mobile terminal products is influenced.
The optical fingerprint identification naturally has the advantage of long-distance induction due to the use of an optical mode, but the optical fingerprint identification device can only be made very small due to the requirement of high resolution, and the signal quantity of the optical fingerprint identification device is quite weak because the signal quantity is generally in direct proportion to the area of the optical fingerprint identification device; therefore, when detecting fingerprint signals, active detection circuits are usually used to improve the signal-to-noise ratio.
When an active pixel circuit is used to detect a fingerprint optical signal with ground light intensity, since an optical fingerprint identification device, such as a PIN, generates a very weak photocurrent under a weak light intensity, if an off-state leakage current of a reset transistor is large (usually, when the off-state leakage current is larger than the photocurrent), a signal-to-noise ratio of the fingerprint signal is reduced, and even a fingerprint cannot be detected directly.
Disclosure of Invention
The present invention is directed to at least one of the technical problems in the prior art, and provides a fingerprint identification detection circuit, a driving method thereof, and a display device, which improve the fingerprint detection accuracy.
The technical scheme adopted for solving the technical problem of the invention is a fingerprint identification detection circuit, which comprises: the device comprises a reset unit, a photosensitive unit, a current generation unit, a switch unit and a reset voltage supply unit; wherein the content of the first and second substances,
the reset voltage supply unit is used for providing a first reset voltage for the reset unit in a reset phase and providing a second reset voltage for the reset unit in an integration phase so as to enable the reset unit to generate stable leakage current;
the reset unit is used for resetting the potential of the G node through the first reset voltage under the control of a reset signal; the G node is a connecting node among the reset unit, the photosensitive unit and the current generation unit;
the photosensitive unit is used for generating corresponding electric signals according to the optical signals sensed by the photosensitive unit;
the current generation unit is used for generating corresponding leakage current according to the received electric signal;
and the switch unit is used for outputting the leakage current output by the current generation unit under the control of the scanning signal so as to identify the fingerprint information.
Preferably, the fingerprint identification detection circuit further includes: and the voltage adjusting unit is used for leading out the leakage current generated by the resetting unit through the control of the non-working level in the integrating stage.
Further preferably, the voltage adjusting unit includes a voltage adjusting transistor; wherein the content of the first and second substances,
and a first pole of the voltage adjusting transistor is connected with a G node, a second pole of the voltage adjusting transistor is connected with a low power supply voltage end, and a control pole of the voltage adjusting transistor is connected with a non-working level end.
Preferably, the reset unit includes: a reset transistor; wherein the content of the first and second substances,
the first pole of the reset transistor is connected with the reset voltage supply unit, the second pole of the reset transistor is connected with the G node, and the control pole of the reset transistor is connected with the reset signal line.
Preferably, the current generation unit includes: a follower transistor; wherein the content of the first and second substances,
the first pole of the following transistor is connected with a power supply end voltage end, the second pole of the following transistor is connected with the switch unit, and the control pole of the following transistor is connected with the G node.
Preferably, the photosensitive unit includes: a photodiode; wherein the content of the first and second substances,
the first pole of the photodiode is connected with a G node, and the second pole of the photodiode is connected with a bias voltage end.
Preferably, the switching unit includes: a switching transistor; wherein the content of the first and second substances,
the first pole of the switch transistor is connected with the current generation unit, the second pole of the switch transistor is connected with the signal output end, and the control pole of the switch transistor is connected with the scanning line.
The technical scheme adopted for solving the technical problem of the invention is a driving method of the fingerprint identification detection circuit, which comprises the following steps:
a reset stage: the reset signal is a working level signal, the reset unit is turned on, and the reset voltage generation unit outputs a first reset voltage to the reset unit so that the reset unit resets the potential of the G node through the first reset voltage;
an integration stage: the reset voltage supply unit outputs a second reset voltage to the reset unit so that the reset unit generates stable leakage current, and meanwhile, the photosensitive unit converts the optical signal sensed by the photosensitive unit into an electric signal;
a data reading stage: and a working level signal is input to the scanning line, the switch unit is opened, and the current generation unit generates a corresponding current signal according to the received electric signal generated by the photosensitive unit and outputs the corresponding current signal through the switch unit so as to be used for the control unit to identify the fingerprint information.
Preferably, the reset phase further comprises:
and a working level signal is input to the scanning line, and the switch unit is opened to detect the current signal output by the reset unit so that the control unit can detect the noise generated by the reset unit under the driving of the first reset voltage.
The technical scheme adopted for solving the technical problem of the invention is a display device which comprises the fingerprint identification detection circuit.
The invention has the following beneficial effects:
in the fingerprint identification detection circuit, the reset voltage supply module provides the second reset voltage for the reset unit in the integration stage so that the reset unit generates stable leakage current, that is, although the potential of the G node begins to drop after the light reflected by the valleys and the ridges in the fingerprint information irradiates the photosensitive unit in the integration stage, the voltage loaded at two ends of the reset unit is always enabled by selecting the proper second reset voltage, and the leakage current noise generated by the reset unit can be enabled to be stable in the stage, so that the noise is stable although the interference of the leakage current noise of the reset unit exists, and the leakage current noise is easily obtained at the moment, so that the acquired fingerprint information is more accurate in the subsequent data reading stage.
Drawings
Fig. 1 is a schematic structural diagram of a fingerprint identification detection circuit according to embodiment 1 of the present invention;
FIG. 2 is a schematic diagram of a fingerprint identification detection circuit according to embodiment 1 of the present invention;
FIG. 3 is a graph of the source-drain electrode voltage difference of a transistor versus the leakage current generated by the transistor;
FIG. 4 is a timing diagram illustrating the operation of the fingerprint identification detection circuit according to embodiments 1 and 2 of the present invention;
FIG. 5 is a circuit diagram of a reset phase of the fingerprint identification detection circuit according to embodiment 1 of the present invention;
FIG. 6 is a circuit diagram of the integration phase of the fingerprint identification detection circuit according to embodiment 1 of the present invention;
FIG. 7 is a circuit diagram of a data reading stage of the fingerprint identification detection circuit according to embodiment 1 of the present invention;
FIG. 8 is a schematic structural diagram of a fingerprint identification detection circuit according to embodiment 2 of the present invention;
FIG. 9 is a schematic diagram of a fingerprint identification detection circuit according to embodiment 2 of the present invention;
FIG. 10 is a circuit diagram of the reset phase of the fingerprint identification detection circuit according to embodiment 2 of the present invention;
FIG. 11 is a circuit diagram of the integration phase of the fingerprint identification detection circuit according to embodiment 2 of the present invention;
FIG. 12 is a circuit diagram of the data reading stage of the fingerprint identification detection circuit according to embodiment 2 of the present invention.
Detailed Description
In order to make the technical solutions of the present invention better understood, the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
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 since the source and the drain of the transistors used may be interchanged under certain conditions, the source and the drain are not different from the description of the connection relationship. In the embodiment of the present invention, to distinguish the source and the drain of the transistor, one of the poles is referred to as a first pole, the other pole is referred to as a second pole, and the gate is referred to as a control pole. Further, the transistors can be classified into N-type and P-type according to their characteristics, and the following embodiments will be described with reference to the transistors as N-type transistors. When an N-type transistor is adopted, the first pole is the source electrode of the N-type transistor, the second pole is the drain electrode of the N-type transistor, when the grid electrode inputs a high level, the source electrode and the drain electrode are conducted, and the P type is opposite. It is contemplated that implementing a transistor as a P-type transistor will be readily apparent to one skilled in the art without inventive effort and is therefore within the scope of the embodiments of the present invention.
In this embodiment, the non-operating level end refers to a low level end, the operating level refers to a high level, and the non-operating level refers to a low level.
Example 1:
as shown in fig. 1, the present embodiment provides a fingerprint identification detection circuit, including: the device comprises a reset unit, a photosensitive unit, a current generation unit, a switch unit and a reset voltage supply unit; the reset voltage supply unit is used for providing a first reset voltage Vrst1 for the reset unit in a reset phase and providing a second reset voltage Vrst2 for the reset unit in an integration phase so as to enable the reset unit to generate stable leakage current; the reset unit is used for resetting the potential of the G node through a first reset voltage Vrst1 under the control of a reset signal; the G node is a connecting node among the reset unit, the photosensitive unit and the current generation unit; the photosensitive unit is used for generating corresponding electric signals according to the optical signals sensed by the photosensitive unit; the current generation unit is used for generating corresponding leakage current according to the received electric signal; the switch unit is used for outputting the leakage current output by the current generation unit under the control of the scanning signal so as to identify the fingerprint information.
In the fingerprint identification detection circuit, the reset voltage supply module provides the second reset voltage Vrst2 for the reset unit in the integration stage so that the reset unit generates stable leakage current, that is, although the potential of the G node begins to drop after the light reflected by the valleys and ridges in the fingerprint information irradiates the photosensitive unit in the integration stage, the voltage loaded at the two ends of the reset unit is always enabled by selecting the proper second reset voltage Vrst2, and the leakage current noise generated by the reset unit can be stabilized in the stage, so that although the interference of the leakage current noise of the reset unit exists, the noise is stable, and the leakage current noise is easily obtained at the moment, and the acquired fingerprint information is more accurate in the subsequent data reading stage. It should be noted that, because the light quantity reflected by the valley and the ridge are different, the electrical signals generated by the light sensing unit are different, so that the current signals generated by the current generating unit are different, and thus the signals of the valley and the ridge can be judged according to the magnitude of the signal output by the switch unit, so as to realize the fingerprint identification.
As shown in fig. 2, the reset unit includes: a reset transistor Mrst; the Reset transistor Mrst has a first electrode connected to a Reset voltage supply unit, a second electrode connected to a G node, and a control electrode connected to a Reset signal line Reset.
Specifically, in the Reset phase, when a high-level signal is input to the Reset signal line Reset, the Reset transistor Mrst is turned on, and the first Reset voltage Vrst1 is input to the Reset voltage supply unit, so that the Reset of the G node, that is, the Reset of the light sensing unit can be realized.
In the integration stage, when a low-level signal is input to the Reset signal line Reset, the Reset transistor Mrst is turned off, and the second Reset voltage Vrst2 is input to the Reset voltage supply unit, at this time, although the light sensing unit starts integrating in this stage, the potential of the G node gradually decreases, and in accordance with the relationship between the transistor source-drain voltage difference and the generated leakage current of this transistor, specifically, as shown in fig. 3, when the source-drain voltage difference is about less than 200mv, Id exhibits a drastic change, and cannot be fitted with a simple linear fit. If the source and drain voltages of the transistor are set to a suitable level much greater than 200mv, the leakage current Id can be kept substantially constant over a wide range. From the coordinate points (1.9964,1.344), (2.9937,1.3462) in the graph, it can be seen that the current changed by only 0.0022pA when Vd changed by 1V. If the photocurrent is 0.2pA at low light intensity, Id can be approximated as a constant current source. After constant current is integrated for a fixed time, a fixed potential change is generated, and a base value is formed, and the base value can be easily removed through a plurality of methods. The second reset voltage Vrst2 can be set to a magnitude that allows the source-drain voltage (i.e., the voltages of the first and second electrodes) applied to the reset transistor Mrst to make the leakage current generated by the reset transistor Mrst constant according to the above principle. Therefore, the subsequent control unit can acquire the noise generated by the reset transistor Mrst in the integration stage, and the accuracy of fingerprint identification information is ensured.
Wherein, the photosensitive unit includes: a photodiode PIN 1; the photodiode PIN1 has a first pole connected to the G node and a second pole connected to a bias voltage terminal VB.
Specifically, the photodiode PIN1 may generate different electrical signals according to the amount of light received.
Wherein the current generation unit includes: a following transistor Msf; the following transistor Msf has a first electrode connected to the power supply voltage terminal VDD, a second electrode connected to the switching unit, and a control electrode connected to the G node.
Specifically, in the data reading stage, the electrical signal generated by the photosensitive cell is applied to the control electrode of the following transistor Msf, and the following transistor Msf outputs different current signals according to the magnitude of the applied electrical signal, so as to identify the fingerprint information.
Wherein the switching unit includes a switching transistor Mg; the first pole of the switching transistor Mg is connected with the current generation unit, the second pole is connected with the signal output end, and the control pole is connected with the scanning line Gate.
Specifically, when the fingerprint identification detection circuit in this embodiment is applied to a display panel, a plurality of fingerprint identification detection circuits may be disposed in the display panel, and particularly may be disposed in one-to-one correspondence with pixel units, so as to implement full-screen fingerprint identification. At this time, the signal output end of the fingerprint identification detection circuit located in the same column can be connected with the same reading line, and the control electrode of the switching transistor Mg of the fingerprint identification detection circuit located in the same row is connected with the same scanning line Gate, so that the wiring of the display panel is facilitated.
This completes the description of each part of the fingerprint identification detection circuit in the present embodiment. The following provides a driving method of the fingerprint identification detection circuit. The method specifically comprises the following steps:
a reset stage: the reset signal is an operating level signal, the reset unit is turned on, and the reset voltage generation unit outputs a first reset voltage Vrst1 to the reset unit, so that the reset unit resets the potential of the G node by the first reset voltage Vrst 1.
Preferably, after the reset of the potential of the G node is completed, an operation level signal is input to the scan line Gate, and the switching unit is turned on to detect a current signal output from the reset unit, so that the control unit detects noise generated by the reset unit under the driving of the first reset voltage Vrst 1.
An integration stage: the reset voltage supply unit outputs a second reset voltage Vrst2 to the reset unit, so that the reset unit generates a stable leakage current, and at the same time, the light sensing unit converts the light signal sensed by the light sensing unit into an electrical signal.
A data reading stage: and a working level signal is input to the scanning line Gate, the switch unit is opened, and the current generation unit generates a corresponding current signal according to the received electric signal generated by the photosensitive unit and outputs the corresponding current signal through the switch unit so as to be used for the control unit to identify the fingerprint information.
In order to make the operation of the fingerprint identification detection circuit more clear, the operation of the fingerprint identification detection circuit in this embodiment will be described in detail with reference to fig. 4 and fig. 5-7.
As shown in fig. 2, there is provided a preferred fingerprint recognition detection circuit, which includes: the device comprises a reset unit, a current generation unit, a switch unit, a photosensitive unit and a reset voltage supply unit; wherein, the reset unit includes: a reset transistor Mrst; the current generation unit includes: a following transistor Msf; the photosensitive unit includes: a photodiode PIN 1; the switch unit includes: a switching transistor Mg; the first pole of the Reset transistor Mrst is connected with the Reset voltage supply unit, the second pole of the Reset transistor Mrst is connected with the G node, and the control pole of the Reset transistor Mrst is connected with the Reset signal line Reset; a first pole of the following transistor Msf is connected with a power supply voltage end VDD, a second pole of the following transistor Msf is connected with a first pole of the switching transistor Mg, and a control pole of the following transistor Msf is connected with a G node; a first pole of the photodiode PIN1 is connected to the G node, and a second pole is connected to a bias voltage terminal VB; the first pole of the switching transistor Mg is connected with the current generation unit, the second pole of the switching transistor Mg is connected with the signal output end, and the control pole of the switching transistor Mg is connected with the scanning line Gate.
The driving method of the fingerprint identification detection circuit will be specifically described with reference to the timing chart shown in fig. 4. The method specifically comprises the following steps:
reset phase (T1): as shown in fig. 5, when a high-level signal is input to the Reset signal line Reset, the Reset transistor Mrst is turned on, and the Reset voltage supply unit supplies the first Reset voltage Vrst1, the Reset of the G node, that is, the Reset of the light sensing unit may be performed.
Preferably, at this stage, after the reset of the potential of the G node by the first reset voltage Vrst1 is completed, a high level signal is input to the scan line Gate, and the switching transistor Mg is turned on to detect a current signal output by the reset transistor Mrst for the control unit to detect noise generated by the reset transistor Mrst driven by the first reset voltage Vrst 1.
Integration phase (T2): as shown in fig. 6, the Reset signal line Reset inputs a low level signal, and the Reset voltage supply unit inputs a second Reset voltage Vrst2, and the second Reset voltage Vrst2 can ensure that the output leakage current noise of the Reset transistor Mrst is stable when the potential of the G node drops due to the integration point of the photodiode PIN1 at this stage; at the same time, photodiode PIN1 converts the optical signal it senses into an electrical signal.
Data read phase (T3): as shown in fig. 7, a high level signal is input to the scan line Gate, the switching transistor Mg is turned on, and the follower transistor Msf generates a corresponding current according to an electrical signal output from the photodiode PIN1 and outputs the current via the switching transistor Mg for fingerprint information recognition.
Example 2:
as shown in fig. 8, the present embodiment provides a fingerprint identification detection circuit including not only the reset unit, the light sensing unit, the current generation unit, the switch unit, the reset voltage supply unit in embodiment 1; in particular, the device also comprises a voltage adjusting unit which is used for leading out the leakage current generated by the reset unit through the control of a non-working level in an integration stage. The reset unit, the photosensitive unit, the current generating unit, the switching unit, and the reset voltage supplying unit are not described in detail in this embodiment, and are fully consistent with the functions of embodiment 1.
The fingerprint identification detection circuit of the embodiment can provide the second reset voltage Vrst2 for the reset unit in the integration stage through the reset voltage supply module, so that the reset unit generates stable leakage current, that is, although the potential of the G node starts to drop after light reflected by valleys and ridges in fingerprint information is irradiated to the photosensitive unit in the integration stage, the voltage loaded at two ends of the reset unit is always enabled to be stable in the stage by selecting the proper second reset voltage Vrst2, and the leakage current noise generated by the reset unit can be led out through the control of the non-working level in the integration stage due to the addition of the voltage adjusting unit, so that the influence of the leakage current noise on the accuracy of fingerprint information detection in low brightness can be eliminated.
As shown in fig. 9, the voltage adjustment unit includes a voltage adjustment transistor Mt; the voltage-adjusting transistor Mt has a first electrode connected to the G node, a second electrode connected to the low power supply voltage terminal VSS, and a control electrode connected to the non-operating level terminal.
Specifically, in the integration phase, when a low-level signal is input to the Reset signal line Reset, the Reset transistor Mrst is turned off, and the Reset voltage supply unit inputs the second Reset voltage Vrst2, at this time, although the photosensitive cell starts integrating at this stage, the potential of the G node gradually decreases, and according to the relationship between the source-drain voltage difference of the transistor and the generated leakage current of the transistor, by setting the second reset voltage Vrst2 to a level that makes the source-drain voltages (i.e., the voltages of the first and second electrodes) applied to the reset transistor Mrst constant, the drain current generated by the reset transistor Mrst is controlled by the low-level signal inputted from the low-level terminal to control the voltage-adjusting transistor Mt, so that the leakage current generated by the reset transistor Mrst is introduced to the low-level voltage terminal through the voltage adjustment transistor Mt, the influence of leakage current noise on the accuracy of fingerprint information detection can be eliminated when the brightness is low.
Specifically, when the fingerprint identification detection circuit in this embodiment is applied to a display panel, a plurality of fingerprint identification detection circuits may be disposed in the display panel, and particularly may be disposed in one-to-one correspondence with pixel units, so as to implement full-screen fingerprint identification. At this time, the signal output end of the fingerprint identification detection circuit located in the same column can be connected with the same reading line, and the control electrode of the switching transistor Mg of the fingerprint identification detection circuit located in the same row is connected with the same scanning line Gate, so that the wiring of the display panel is facilitated.
In order to make the operation of the fingerprint identification detection circuit in the present embodiment more clear, the operation will be specifically described with reference to fig. 2 and fig. 10 to 12.
As shown in fig. 9, there is provided a preferred fingerprint recognition detection circuit, which includes: the device comprises a reset unit, a current generation unit, a switch unit, a photosensitive unit, a reset voltage supply unit and a voltage adjustment unit; wherein, the reset unit includes: a reset transistor Mrst; the current generation unit includes: a following transistor Msf; the photosensitive unit includes: a photodiode PIN 1; the switch unit includes: the switching transistor Mg voltage adjusting unit includes: a voltage adjustment transistor Mt; the first pole of the Reset transistor Mrst is connected with the Reset voltage supply unit, the second pole of the Reset transistor Mrst is connected with the G node, and the control pole of the Reset transistor Mrst is connected with the Reset signal line Reset; a first pole of the following transistor Msf is connected with a power supply voltage end VDD, a second pole of the following transistor Msf is connected with a first pole of the switching transistor Mg, and a control pole of the following transistor Msf is connected with a G node; a first pole of the photodiode PIN1 is connected to the G node, and a second pole is connected to a bias voltage terminal VB; the first pole of the switching transistor Mg is connected with the current generation unit, the second pole of the switching transistor Mg is connected with the signal output end, and the control pole of the switching transistor Mg is connected with the scanning line Gate.
The driving method of the fingerprint identification detection circuit will be specifically described with reference to the timing chart shown in fig. 2. The method specifically comprises the following steps:
reset phase (T1): as shown in fig. 10, when a high-level signal is input to the Reset signal line Reset, the Reset transistor Mrst is turned on, and the first Reset voltage Vrst1 is input to the Reset voltage supply unit, the Reset of the G node, that is, the Reset of the light sensing unit can be realized.
Preferably, at this stage, after the reset of the potential of the G node by the first reset voltage Vrst1 is completed, a high level signal is input to the scan line Gate, and the switching transistor Mg is turned on to detect a current signal output by the reset transistor Mrst for the control unit to detect noise generated by the reset transistor Mrst driven by the first reset voltage Vrst 1.
Integration phase (T2): as shown in fig. 11, the Reset signal line Reset inputs a low level signal, and the Reset voltage supply unit inputs a second Reset voltage Vrst2, and the second Reset voltage Vrst2 can ensure that the output leakage current noise of the Reset transistor Mrst is stable when the potential of the G node drops due to the integration point of the photodiode PIN1 at this stage; and the low level signal input by the low level end controls the voltage adjusting transistor Mt, so that the leakage current generated by the reset transistor Mrst is introduced into the low level voltage end through the voltage adjusting transistor Mt, and the influence of the leakage current noise on the accuracy of fingerprint information detection can be eliminated when the brightness is low. At the same time, photodiode PIN1 converts the optical signal it senses into an electrical signal.
Data read phase (T3): as shown in fig. 12, a high level signal is input to the scan line Gate, the switching transistor Mg is turned on, and the follower transistor Msf generates a corresponding current according to an electrical signal output from the photodiode PIN1 and outputs the current via the switching transistor Mg for fingerprint information recognition.
Example 3:
the present embodiment provides a display device including the fingerprint identification detection circuit in embodiment 1 or 2, and therefore, the display device can realize accurate fingerprint identification on a full screen.
Of course, the display device in this embodiment may include: the OLED display panel comprises any product or component with a display function, such as an OLED panel, a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, a navigator and the like.
It will be understood that the above embodiments are merely exemplary embodiments taken to illustrate the principles of the present invention, which is not limited thereto. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit and substance of the invention, and these modifications and improvements are also considered to be within the scope of the invention.
Claims (10)
1. A fingerprint identification detection circuit, comprising: the device comprises a reset unit, a photosensitive unit, a current generation unit, a switch unit and a reset voltage supply unit; wherein the content of the first and second substances,
the reset voltage supply unit is used for providing a first reset voltage for the reset unit in a reset phase and providing a second reset voltage for the reset unit in an integration phase so as to enable the reset unit to generate stable leakage current;
the reset unit is used for resetting the potential of the G node through the first reset voltage under the control of a reset signal; the G node is a connecting node among the reset unit, the photosensitive unit and the current generation unit;
the photosensitive unit is used for generating corresponding electric signals according to the optical signals sensed by the photosensitive unit;
the current generation unit is used for generating corresponding leakage current according to the received electric signal;
and the switch unit is used for outputting the leakage current output by the current generation unit under the control of the scanning signal so as to identify the fingerprint information.
2. The fingerprint identification detection circuit of claim 1, further comprising: and the voltage adjusting unit is used for leading out the leakage current generated by the resetting unit through the control of the non-working level in the integrating stage.
3. The fingerprint identification detection circuit of claim 2, wherein the voltage adjustment unit comprises a voltage adjustment transistor; wherein the content of the first and second substances,
and a first pole of the voltage adjusting transistor is connected with a G node, a second pole of the voltage adjusting transistor is connected with a low power supply voltage end, and a control pole of the voltage adjusting transistor is connected with a non-working level end.
4. The fingerprint identification detection circuit of claim 1, wherein the reset unit comprises: a reset transistor; wherein the content of the first and second substances,
the first pole of the reset transistor is connected with the reset voltage supply unit, the second pole of the reset transistor is connected with the G node, and the control pole of the reset transistor is connected with the reset signal line.
5. The fingerprint identification detection circuit of claim 1, wherein the current generation unit comprises: a follower transistor; wherein the content of the first and second substances,
the first pole of the following transistor is connected with a power supply end voltage end, the second pole of the following transistor is connected with the switch unit, and the control pole of the following transistor is connected with the G node.
6. The fingerprint identification detection circuit of claim 1, wherein the light sensing unit comprises: a photodiode; wherein the content of the first and second substances,
the first pole of the photodiode is connected with a G node, and the second pole of the photodiode is connected with a bias voltage end.
7. The fingerprint recognition detection circuit of claim 1, wherein the switching unit comprises: a switching transistor; wherein the content of the first and second substances,
the first pole of the switch transistor is connected with the current generation unit, the second pole of the switch transistor is connected with the signal output end, and the control pole of the switch transistor is connected with the scanning line.
8. A method of driving the fingerprint recognition detection circuit according to any one of claims 1 to 7, comprising:
a reset stage: the reset signal is a working level signal, the reset unit is turned on, and the reset voltage generation unit outputs a first reset voltage to the reset unit so that the reset unit resets the potential of the G node through the first reset voltage;
an integration stage: the reset voltage supply unit outputs a second reset voltage to the reset unit so that the reset unit generates stable leakage current, and meanwhile, the photosensitive unit converts the optical signal sensed by the photosensitive unit into an electric signal;
a data reading stage: and a working level signal is input to the scanning line, the switch unit is opened, and the current generation unit generates a corresponding current signal according to the received electric signal generated by the photosensitive unit and outputs the corresponding current signal through the switch unit so as to be used for the control unit to identify the fingerprint information.
9. The method of claim 8, wherein the reset phase further comprises:
and a working level signal is input to the scanning line, and the switch unit is opened to detect the current signal output by the reset unit so that the control unit can detect the noise generated by the reset unit under the driving of the first reset voltage.
10. A display device comprising the fingerprint identification detection circuit of any one of claims 1-7.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201810072280.5A CN108280432B (en) | 2018-01-25 | 2018-01-25 | Fingerprint identification detection circuit, driving method thereof and display device |
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| CN201810072280.5A CN108280432B (en) | 2018-01-25 | 2018-01-25 | Fingerprint identification detection circuit, driving method thereof and display device |
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| CN110763336B (en) * | 2018-07-26 | 2021-03-09 | 京东方科技集团股份有限公司 | Photodetection circuit, electronic device, and driving method |
| CN109147593A (en) * | 2018-08-31 | 2019-01-04 | Oppo广东移动通信有限公司 | Display component and electronic equipment |
| CN109298804B (en) * | 2018-10-23 | 2022-10-28 | 京东方科技集团股份有限公司 | Touch circuit and driving method thereof, touch substrate and display device |
| CN110008860B (en) * | 2019-03-21 | 2021-09-24 | 武汉华星光电技术有限公司 | Fingerprint identification framework and touch panel |
| CN109872683B (en) * | 2019-03-28 | 2020-08-25 | 京东方科技集团股份有限公司 | Pixel circuit, display panel and driving method |
| CN110010046B (en) * | 2019-04-22 | 2022-07-19 | 京东方科技集团股份有限公司 | Display panel, detection method thereof and display device |
| CN110214350B (en) * | 2019-04-25 | 2022-12-06 | 京东方科技集团股份有限公司 | Drive circuit, array substrate, display device and drive method |
| CN112148143B (en) * | 2019-06-27 | 2024-01-23 | 京东方科技集团股份有限公司 | Detection circuit, driving method and substrate |
| CN110245649B (en) * | 2019-07-31 | 2021-12-28 | 上海天马微电子有限公司 | Display panel, driving method and display device |
| CN110796983B (en) * | 2019-11-13 | 2021-06-11 | 厦门天马微电子有限公司 | Display device and driving method thereof |
| CN113544695B (en) * | 2020-02-19 | 2024-04-12 | 京东方科技集团股份有限公司 | Photosensitive detection circuit, optical signal detection method, device and system and display device |
| EP4163818A1 (en) | 2020-06-09 | 2023-04-12 | Wuhan China Star Optoelectronics Technology Co., Ltd. | Optical fingerprint recognition circuit and display panel |
| CN111639622B (en) * | 2020-06-09 | 2021-07-06 | 武汉华星光电技术有限公司 | Optical fingerprint identification circuit and display panel |
| CN114616601A (en) | 2020-09-11 | 2022-06-10 | 京东方科技集团股份有限公司 | Fingerprint identification circuit, driving method thereof, display panel and display device |
| CN114187870B (en) * | 2020-09-14 | 2023-05-09 | 京东方科技集团股份有限公司 | Photoelectric detection circuit, driving method thereof, display device and manufacturing method thereof |
| JP2023078838A (en) * | 2021-11-26 | 2023-06-07 | 株式会社ジャパンディスプレイ | detector |
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