CN110956162B - Fingerprint identification circuit, working method thereof, display panel and display device - Google Patents
Fingerprint identification circuit, working method thereof, display panel and display device Download PDFInfo
- Publication number
- CN110956162B CN110956162B CN201911307055.6A CN201911307055A CN110956162B CN 110956162 B CN110956162 B CN 110956162B CN 201911307055 A CN201911307055 A CN 201911307055A CN 110956162 B CN110956162 B CN 110956162B
- Authority
- CN
- China
- Prior art keywords
- signal
- fingerprint
- transistor
- fingerprint identification
- input
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- 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
Abstract
The invention discloses a fingerprint identification circuit and a working method thereof, a display panel and a display device, belonging to the technical field of display, wherein the fingerprint identification circuit comprises a fingerprint identification unit, a comparison unit and a selection unit, wherein the selection unit provides a fingerprint current signal to a fingerprint current output end and also provides a reference current signal to a reference current output end; and reading the fingerprint identification signal according to the difference value of the fingerprint current signal and the reference current signal. The working method of the fingerprint identification circuit comprises the following steps: signal reset stage, signal detection stage, signal reading stage. The display panel comprises the fingerprint identification circuit. The display device comprises the display panel. The invention simultaneously outputs the interference signal and the fingerprint signal at the same time, and then deducts the interference signal and the fingerprint signal, thereby avoiding the situation that other variables are possibly introduced when the fingerprint signal is read at different time points, further improving the signal-to-noise ratio of the fingerprint identification signal, enhancing the anti-interference capability and being beneficial to improving the fingerprint identification effect.
Description
Technical Field
The invention relates to the technical field of display, in particular to a fingerprint identification circuit, a working method of the fingerprint identification circuit, a display panel and a display device.
Background
A fingerprint is an unchanging feature that is unique to the human body and distinguishable from others, and consists of a series of ridges and valleys on the surface of the skin at the finger tip, the composition details of which typically include the branches of the ridges, the ends of the ridges, the arches, the tent-like arches, the left-handed, right-handed, spiral, or double-handed details, which determine the uniqueness of the fingerprint pattern. With the rapid development of display technologies, display panels with fingerprint identification functions have gradually spread throughout the lives of people, and fingerprint identification is widely applied to display screens of electronic devices such as mobile phones, personal digital assistants, computers and the like, so that the functions of the display screens are enriched, and meanwhile, the safety performance of the display screens is improved.
Among the display device that prior art provided, need additionally to increase the fingerprint identification module in order to realize the fingerprint identification function, after making respectively and accomplish display panel and fingerprint identification module, assemble the two in order to realize the electricity and connect, consequently increased display device's technology processing procedure to the fingerprint identification module probably occupies certain region in display device, is unfavorable for realizing the full face screen.
With the rise of the full screen technology, fingerprint identification is gradually developed from the design outside the display screen to the design inside the display screen, namely, the fingerprint identification technology under the screen is pursued to obtain higher screen occupation ratio. Specifically, integrate a plurality of fingerprint identification components and parts in display panel's display area, form fingerprint identification components and parts array, then set up drive circuit through the frame district at display panel, realize the drive of fingerprint identification components and parts array, accomplish fingerprint identification. Although the display device for fingerprint identification in the integrated screen has a simple structure, because the fingerprint identification mode adopts signal difference comparison in different time periods, noise or other interference factors caused by time difference can be introduced, so that the signal-to-noise ratio is reduced, the anti-noise interference capability is poor, and the fingerprint identification effect is easily influenced.
Therefore, it is an urgent technical problem to be solved by those skilled in the art to provide a fingerprint identification circuit, a working method thereof, a display panel and a display device, which can improve the anti-interference capability and the signal-to-noise ratio and improve the fingerprint identification effect.
Disclosure of Invention
In view of the above, the present invention provides a fingerprint identification circuit, a working method thereof, a display panel and a display device, so as to solve the problems of difficulty in fingerprint identification and poor identification effect caused by low signal-to-noise ratio and poor anti-noise interference capability of the fingerprint identification circuit in the prior art.
The invention provides a fingerprint identification circuit, which comprises a fingerprint identification unit, wherein the fingerprint identification unit comprises a reset signal input end, a reference voltage input end and a grounding voltage input end, the fingerprint identification unit is connected with a fingerprint voltage signal node, and the fingerprint identification unit provides a fingerprint voltage signal to the fingerprint voltage signal node; the comparison unit comprises a reset signal input end, a reference voltage input end and a grounding voltage input end, is connected with the reference voltage signal node and provides a reference voltage signal to the reference voltage signal node; the fingerprint current detection device comprises a selection unit, a fingerprint current detection unit and a fingerprint detection unit, wherein the selection unit comprises a current signal input end, an input control signal end, a fingerprint current output end and a reference current output end, is connected with a fingerprint voltage signal node and a reference voltage signal node, and provides a fingerprint current signal to the fingerprint current output end and also provides a reference current signal to the reference current output end; and reading the fingerprint identification signal according to the difference value of the fingerprint current signal and the reference current signal.
Based on the same invention concept, the invention also provides a working method of the fingerprint identification circuit, which is used for the fingerprint identification circuit to carry out fingerprint identification work; the working method at least comprises the following steps: a signal resetting stage, a signal detecting stage and a signal reading stage; in a signal resetting phase, a high level is provided for a resetting signal input end and a reference voltage is provided for a reference voltage input end, and the fingerprint identification unit and the comparison unit respond to the high level of the resetting signal input end, provide the reference voltage to a fingerprint voltage signal node and provide the reference voltage to a reference voltage signal node; and, provide the low level to the reset signal input end, the electric potential of the signal node of fingerprint voltage and electric potential of the reference voltage signal node drop to the first voltage value at the same time; in the signal detection stage, the fingerprint identification unit performs light-sensitive fingerprint identification work, and the potential of a fingerprint voltage signal node is continuously reduced to a second voltage value; in the signal reading stage, a high level is provided for an input control signal end, a selection unit responds to the high level of the input control signal end, a current signal input end provides input current, and the selection unit provides a fingerprint current signal to a fingerprint current output end according to the input current and a second voltage value; meanwhile, the selection unit provides a reference current signal to a reference current output end according to the input current and the first voltage value; and reading the difference value of the fingerprint current signal and the reference current signal, and obtaining a fingerprint identification signal according to the difference value to finish fingerprint identification work.
Based on the same inventive concept, the invention also provides a display panel, which comprises the fingerprint identification circuit.
Based on the same inventive concept, the invention also provides a display device comprising the display panel.
Compared with the prior art, the fingerprint identification circuit, the working method thereof, the display panel and the display device provided by the invention at least realize the following beneficial effects:
in the fingerprint identification circuit, the comparison unit plays a comparison role, which is equivalent to background or bottom noise, and the identification signal-to-noise ratio of the fingerprint identification circuit can be improved by deducting the background or bottom noise signal of the comparison unit through the fingerprint signal. The selection unit is a switch for controlling the output of the fingerprint identification signal, and can control the whole fingerprint identification circuit to be opened line by line and read the fingerprint identification signal line by line. The input current signal input by the current signal input end connected with the selection unit passes through the selection unit and then generates two signals of a fingerprint current signal and a reference current signal at the same time, and then the difference of the two signals is compared to judge whether the fingerprint is a valley or a ridge. The fingerprint current signal and the reference current signal are output simultaneously, namely the read interference signal and the fingerprint signal are output at the same time and are deducted, so that the situation that other variables are possibly introduced when the fingerprint signal is read at different time points is avoided, the interference in time can be eliminated, the signal-to-noise ratio of the output fingerprint identification signal is improved, the anti-interference capability of a circuit is enhanced, and the fingerprint identification effect is favorably improved.
Of course, it is not necessary for any product in which the present invention is practiced to specifically achieve all of the above-described technical effects simultaneously.
Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments of the invention, which proceeds with reference to the accompanying drawings.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.
FIG. 1 is a diagram of a fingerprint recognition circuit of the related art;
FIG. 2 is a timing diagram of signals in the ideal operation of FIG. 1;
FIG. 3 is a timing diagram of signals in actual operation of FIG. 1;
FIG. 4 is a schematic diagram of a frame structure of a fingerprint identification circuit according to an embodiment of the present invention;
FIG. 5 is a timing diagram of signals in operation of the fingerprint recognition circuit of FIG. 4;
FIG. 6 is a block diagram of another exemplary embodiment of a fingerprint identification circuit;
FIG. 7 is a schematic diagram of a connection structure of a fingerprint identification circuit according to an embodiment of the present invention;
fig. 8 is a schematic plan view illustrating a display panel according to an embodiment of the present invention;
FIG. 9 is a schematic diagram of a planar structure of the fingerprint recognition circuit of FIG. 8 in a display panel;
FIG. 10 is a schematic diagram of another planar structure of the fingerprint recognition circuit of FIG. 8 within a display panel;
FIG. 11 is a schematic diagram of another planar structure of the fingerprint identification circuit of FIG. 8 within a display panel;
FIG. 12 is a schematic diagram of another planar configuration of the fingerprint sensing circuit of FIG. 8 within a display panel;
fig. 13 is a schematic structural diagram of a display device according to an embodiment of the present invention;
fig. 14 is a schematic plan view of another display device according to an embodiment of the present invention.
Detailed Description
Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.
The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.
Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.
In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be discussed further in subsequent figures.
As shown in fig. 1 to 3, fig. 1 is a related art fingerprinting circuit, fig. 2 is a signal timing diagram of fig. 1 during ideal operation, fig. 3 is a signal timing diagram of fig. 1 during actual operation, and a voltage-mode fingerprinting circuit disclosed in the related art for in-screen fingerprinting includes four switching transistor devices (respectively, a transistor Trst ', a transistor Tsf ', a transistor Tsel ', a transistor Tcol '), 1 photo diode D ', and 1 storage capacitor Cst ', which require five traces of a reset scan line Rst ', a first voltage signal line VDD ', a second voltage signal line VSS ', a selection scan line Sel ', and a voltage signal output line Vout ', wherein the transistor rsel ' and the transistor Trst ' need to be driven line by line through a shift register of a scan driving circuit. The operating principle of the fingerprint identification circuit is shown in fig. 2, and when fingerprint identification is performed, the fingerprint identification circuit comprises a reset stage, an exposure stage and an electric signal output stage:
in the reset stage, the transistor Trst 'is conducted in response to the control signal of the reset scanning line Rst' to reset the fingerprint identification circuit; the reset voltage signal of the first voltage signal line VDD 'is transmitted to the gate of the transistor Tsf', and the voltage signal Vpixel 'at the gate of the transistor Tsf' rises to the input voltage value of the first voltage signal line VDD ', at which time the transistor Tsf' is turned on.
In the exposure stage, a finger contacts the screen, a light source is reflected when irradiating valley lines and ridge lines of a finger fingerprint, and because the reflection angles of the valley lines and the ridge lines and the reflected illumination intensity are different, light is projected onto the photosensitive diode D ', so that the resistance value of the photosensitive diode D' is changed, electric charges are generated, and a photocurrent is formed; due to the leakage current, the voltage signal Vpixel 'at the gate of the transistor Tsf' starts to fall.
An electric signal output stage: because the reflection angles of the fingerprint valley lines and the fingerprint ridge lines and the reflected illumination intensity are different in the exposure stage, the generated photocurrents are different, the change values of the voltage signals Vpixel ' are different, the fingerprint signals detected by the voltage signal output lines Vout ' are also different, and the fingerprint identification function is realized by detecting the voltage signals of the voltage signal output lines Vout '.
Although the voltage signal Vpixel 'at the gate of the transistor Tsf' is decreased by the influence of the photocurrent, the transistor Tsel 'is turned on in response to the control signal of the selection scan line Sel', the transistor Tcol 'is turned on in response to the control signal of the selection scan line col', the second voltage signal VSS 'is written to the source of the transistor Tsf' (the other end of the transistor Tsf 'opposite to the first voltage signal line VDD'), and the decreased voltage signal Vpixel 'can still turn on the transistor Tsf'; the input voltage of the first voltage signal line VDD 'is connected to the drain of the transistor Tsf', and the transistor Tsf 'can divide the output of the fingerprint voltage signal of the voltage signal output line Vout' to realize the fingerprint identification and detection function.
After the reset phase is finished, the voltage signal Vpixel 'is restored to the voltage of the voltage signal line VDD', at this time, the transistor Tsel 'is turned on to perform voltage signal acquisition once, and the fingerprint output signal of the acquired voltage signal output line Vout' is an initial signal. After a period of fingerprint identification time, the voltage change value a 'of the voltage signal Vpixel' is different (as shown in fig. 2) because of different light intensities reflected by the valleys and ridges of the fingerprint, when the transistor Tsel 'is turned on to perform secondary voltage signal acquisition, the voltage signal output line Vout' can output different signals, and finally, a fingerprint image can be obtained through signal processing.
However, in the actual operation of the fingerprint identification circuit, because of the existence of the capacitive coupling effect (which refers to the phenomenon that if there is a coupling capacitance between the gate and the source/drain of the transistor, the source/drain potential is pulled up or down under the influence of the gate voltage change when the gate voltage of the transistor is turned off), the voltage signal Vpixel 'is connected to the source/drain of the transistor Trst', and when the gate signal of the transistor Trst 'changes from high to low (the transistor Trst' changes from on to off), the voltage signal Vpixel 'is also pulled down, as shown by a reference F' in fig. 3. At this time, for the valleys and ridges of the fingerprint, there should be a difference amount of the voltage signals Vpixel ' marked with a ' value in fig. 2, and now the difference amount becomes a difference amount of a ' -F ' = B ' due to the capacitive coupling effect, which in turn causes a difference between the valley recognition signal and the ridge recognition signal of the fingerprint to become small, so that the difficulty of fingerprint recognition increases, and the definition decreases. In addition, because the fingerprint identification mode adopts signal difference comparison in different time periods, noise or other interference factors caused by time differences are introduced, so that the signal-to-noise ratio is reduced, and the fingerprint identification effect is poor.
In view of the above, the present invention provides a fingerprint identification circuit, a working method thereof, a display panel and a display device, so as to solve the problems of difficulty in fingerprint identification and poor identification effect caused by low signal-to-noise ratio and poor anti-noise interference capability of the fingerprint identification circuit in the prior art.
Referring to fig. 4 and 5, fig. 4 is a schematic diagram of a frame structure of a fingerprint identification circuit according to an embodiment of the present invention, fig. 5 is a signal timing diagram of the fingerprint identification circuit of fig. 4 in operation, and a fingerprint identification circuit according to an embodiment of the present invention includes:
the fingerprint identification unit 10 comprises a reset signal input end Rst, a reference voltage input end Ref and a grounding voltage input end GND, the fingerprint identification unit 10 is connected with a fingerprint voltage signal node Q1, and the fingerprint identification unit 10 provides a fingerprint voltage signal Vfp to the fingerprint voltage signal node Q1; optionally, the reset signal input terminal Rst provides a reset signal, the reference voltage input terminal Ref provides a reference voltage Vref, and the ground voltage input terminal GND provides a ground signal;
the comparison unit 20, the comparison unit 20 includes a reset signal input terminal Rst, a reference voltage input terminal Ref and a ground voltage input terminal GND, the comparison unit 20 is connected to a reference voltage signal node Q2, and the comparison unit 20 provides a reference voltage signal Vcom to the reference voltage signal node Q2;
the fingerprint identification device comprises a selection unit 30, wherein the selection unit 30 comprises a current signal input end sig, an input control signal end Sel, a fingerprint current output end I1 and a reference current output end I2, the selection unit 30 is connected with a fingerprint voltage signal node Q1 and a reference voltage signal node Q2, the selection unit 30 provides a fingerprint current signal Ifp to the fingerprint current output end I1 and also provides a reference current signal Icom to the reference current output end I2; and reading a fingerprint identification signal according to the difference value of the fingerprint current signal Ifp and the reference current signal Icom, and obtaining identification signals of fingerprint valleys and fingerprint ridges.
Specifically, in the fingerprint identification circuit provided in this embodiment, the fingerprint identification unit 10 is configured to provide the reference voltage Vref at the reference voltage input terminal Ref to the fingerprint voltage signal node Q1 according to the signal at the reset signal input terminal Rst; the comparing unit 20 is configured to provide a reference voltage Vref at a reference voltage input terminal Ref to a reference voltage signal node Q2 according to a signal at a reset signal input terminal Rst; the selection unit 30 is configured to provide a fingerprint current signal Ifp to the fingerprint current output terminal I1 according to signals of the input control signal end Sel, the current signal input end sig, and the fingerprint voltage signal node Q1, and also to provide a reference current signal Icom to the reference current output terminal I2 according to signals of the input control signal end Sel, the current signal input end sig, and the reference voltage signal node Q2.
Optionally, referring to fig. 4 and fig. 5 in combination, when the fingerprint identification circuit of this embodiment performs fingerprint detection, the fingerprint identification circuit at least includes: a signal reset phase T1, a signal detection phase T2, and a signal read phase T3 (shown in fig. 5).
In the signal reset stage T1, a high level is supplied to the reset signal input terminal Rst and a reference voltage Vref is supplied to the reference voltage input terminal Ref, and the fingerprint identification unit 10 and the comparison unit 20 supply the reference voltage Vref to the fingerprint voltage signal node Q1 and the reference voltage Vref to the reference voltage signal node Q2 in response to the high level of the reset signal input terminal Rst; that is, the fingerprint identification unit 10 and the comparison unit 20 are both reset to the potential of the reference voltage Vref in response to the high level of the reset signal input terminal Rst, the fingerprint voltage signal node Q1 and the reference voltage signal node Q2. Then, a low level is provided to the reset signal input terminal Ref, and due to a capacitive coupling effect, the potential of the fingerprint voltage signal node Q1 and the potential of the reference voltage signal node Q2 simultaneously drop to the first voltage value M; wherein, the difference value between the reference voltage Vref and the first voltage value M is F;
in the signal detection stage T2, the reference voltage signal node Q2 is in a floating state, the fingerprint identification unit 10 performs light-sensing fingerprint identification, and the potential of the fingerprint voltage signal node Q1 continuously decreases to the second voltage value N; the second voltage value N is smaller than the first voltage value M;
in the signal reading stage T3, a high level is provided to the input control signal terminal Sel, the selection unit 30 responds to the high level of the input control signal terminal Sel, the current signal input terminal sig provides the input current Isig, and the selection unit 30 provides the fingerprint current signal Ifp to the fingerprint current output terminal I1 according to the input current Isig and the second voltage value N; meanwhile, the selection unit 30 provides a reference current signal Icom to the reference current output terminal I2 according to the input current Isig and the first voltage value M; and reading a difference value between the fingerprint current signal Ifp and the reference current signal Icom, and obtaining a fingerprint identification signal according to the difference value to finish fingerprint identification work.
The comparison unit 20 of the present embodiment plays a comparison role, which is equivalent to a background or a background noise, and the fingerprint signal subtracts the background or the background noise signal of the comparison unit 30, so as to improve the recognition signal-to-noise ratio of the fingerprint recognition circuit. The selection unit 30 is a switch for controlling the output of the fingerprint identification signal, and the selection unit 30 can control the whole fingerprint identification circuit to be opened line by line and read the fingerprint identification signal line by line. The input current Isig signal inputted from the current signal input end sig connected to the selection unit 30 will generate two signals of the fingerprint current signal Ifp and the reference current signal Icom at the same time after passing through the selection unit 30, and then the difference between the two signals is compared to determine whether the fingerprint is a valley or a ridge. The fingerprint current signal Ifp and the reference current signal Icom of the present embodiment are output simultaneously through the fingerprint identification circuit of the present embodiment, and in the prior art, in order to remove the fingerprint identification noise or other interference signals, the fingerprint signals are generally read once before and after the reset operation phase, and then the detected values of the front and rear signals are subtracted. In the embodiment, the read interference signal and the fingerprint signal are simultaneously output at the same time and then subtracted, and because other variables may be introduced when the fingerprint signal is read at different time points, the embodiment simultaneously outputs the fingerprint current signal Ifp and the reference current signal Icom to eliminate the interference in time, so that the signal-to-noise ratio of the output fingerprint identification signal can be improved, the anti-interference capability of the circuit is enhanced, and the fingerprint identification effect is favorably improved.
It should be noted that the sum of the fingerprint current signal Ifp and the reference current signal Icom of the present embodiment is equal to the input current Isig inputted from the current signal input terminal sig, and since the second voltage value N of the fingerprint voltage signal node Q1 is smaller than the first voltage value M during the signal reading period T3, the reference current signal Icom is closer to the input current Isig but smaller than the input current Isig.
In some optional embodiments, please refer to fig. 6, fig. 6 is a schematic diagram of a frame structure of another fingerprint identification circuit according to an embodiment of the present invention, in this embodiment, the fingerprint identification circuit further includes a differential amplifying unit 40, and the differential amplifying unit 40 reads the fingerprint identification signal FRS according to a difference between the fingerprint current signal Ifp and the reference current signal Icom, so as to complete the fingerprint identification operation.
The fingerprint identification circuit of the embodiment further includes a differential amplifying unit 40, and in the signal reading stage T3, the differential amplifying unit 40 obtains the fingerprint identification signal FRS after the interference is removed according to the difference between the fingerprint current signal Ifp and the reference current signal Icom, so as to further improve the fingerprint identification effect.
It should be noted that, in practical implementation, the fingerprint detection signal of the fingerprint identification circuit can be read through a driving chip (not shown) in the display device, and the differential amplifying unit 40 can also be integrated in the driving chip, thereby being beneficial to realizing a narrow frame of the display device.
In some optional embodiments, please refer to fig. 4 and 7, fig. 7 is a schematic diagram of a connection structure of a fingerprint identification circuit according to an embodiment of the present invention, in which the fingerprint identification unit 10 includes a first transistor T1, a photodiode D, and a first capacitor C1; the control end of the first transistor T1 is connected with a reset signal input end Rst, the first end of the first transistor T1 is connected with a reference voltage input end Ref, and the second end of the first transistor T1 is connected with a fingerprint voltage signal node Q1; a first pole of the photosensitive diode D is connected with a fingerprint voltage signal node Q1, and a second pole of the photosensitive diode D is connected with a grounding voltage input end GND; the first end of the first capacitor C1 is connected with the fingerprint voltage signal node Q1, and the second end of the first capacitor C1 is connected with the grounding voltage input end GND.
With continued reference to fig. 4 and 7, the comparison unit 20 includes a second transistor T2 and a second capacitor C2; the control end of the second transistor T2 is connected to the reset signal input end Rst, the first end of the second transistor T2 is connected to the reference voltage input end Ref, and the second end of the second transistor T2 is connected to the reference voltage signal node Q2; a first end of the second capacitor C2 is connected to the reference voltage signal node Q2, and a second end of the second capacitor C2 is connected to the ground voltage input terminal GND.
With continued reference to fig. 4 and 7, the selection unit 30 includes a third transistor T3, a fourth transistor T4, and a fifth transistor T5; a control end of the third transistor T3 is connected to the fingerprint voltage signal node Q1, a first end of the third transistor T3 is connected to a first end of the fifth transistor T5, and a second end of the third transistor T3 is connected to the fingerprint current output end I1; a control end of the fourth transistor T4 is connected to the reference voltage signal node Q2, a first end of the fourth transistor T4 is connected to a first end of the fifth transistor T5, and a second end of the fourth transistor T4 is connected to the reference current output end I2; the control end of the fifth transistor T5 is connected to the input control signal end Sel, and the second end of the fifth transistor T5 is connected to the current signal input end sig.
Specifically, the fingerprint identification circuit of this embodiment at least includes, when performing fingerprint identification detection operation: optionally, in this embodiment, the first transistor T1, the second transistor T2, the third transistor T3, the fourth transistor T4, and the fifth transistor T5 are all N-type transistors, for example, to explain the working principle of the fingerprint identification circuit of this embodiment, and in specific implementation, the signal resetting stage T1, the signal detecting stage T2, and the signal reading stage T3 (as shown in fig. 5) may be selected according to actual requirements.
Referring to fig. 5 and 7 in combination, during the signal reset period T1, a high level is supplied to the reset signal input terminal Rst and a reference voltage Vref is supplied to the reference voltage input terminal Ref, the first transistor T1 and the second transistor T2 are in a turned-on state in response to the high level of the reset signal input terminal Rst, the reference voltage Vref is transmitted to the fingerprint voltage signal node Q1 through the first transistor T1, and the reference voltage Vref is transmitted to the reference voltage signal node Q2 through the second transistor T2; that is, the first transistor T1 and the second transistor T2 are both reset to the potential of the reference voltage Vref in response to the high level of the reset signal input terminal Rst, the fingerprint voltage signal node Q1 and the reference voltage signal node Q2; because the fingerprint identification circuit has a capacitive coupling effect, when a low level is provided to the reset signal input terminal Rst, the first transistor T1 and the second transistor T2 are in a cut-off state in response to the low level of the reset signal input terminal Rst, so that the potential of the fingerprint voltage signal node Q1 and the potential of the reference voltage signal node Q2 simultaneously drop to a first voltage value M; wherein, the difference value between the reference voltage Vref and the first voltage value M is F;
in the signal detection stage T2, since the first transistor T1 and the second transistor T2 are both in an off state, the fingerprint voltage signal node Q1 and the reference voltage signal node Q2 are in a floating state, but since the photodiode D of the fingerprint identification unit 10 performs a light sensing fingerprint identification operation, when light is irradiated to the photodiode D, the potential of the fingerprint voltage signal node Q1 continuously decreases to the second voltage value N due to a leakage effect; the second voltage value N is smaller than the first voltage value M;
in the signal reading stage T3, a high level is provided to the input control signal terminal Sel, the fifth transistor T5 is in a conducting state in response to the high level of the input control signal terminal Sel, the input current Isig provided by the current signal input terminal sig is respectively transmitted to the first end of the third transistor T3 and the first end of the fourth transistor T4 through the fifth transistor T5, the third transistor T3 is in a conducting state in response to the second voltage value N, and the third transistor T3 provides the fingerprint current signal Ifp to the fingerprint current output terminal I1 according to the input current Isig and the second voltage value N; the fourth transistor T4 is in a conductive state in response to the first voltage value M, and the fourth transistor T4 provides the reference current signal Icom to the reference current output terminal I2 according to the input current Isig and the first voltage value M; the difference between the fingerprint identification unit 10 and the comparison unit 20 is that the fingerprint identification unit 10 has a photodiode D, so that when the signal detection stage T2 performs the light sensing fingerprint detection operation, i.e. under the condition of illumination, the voltages of the fingerprint voltage signal node Q1 and the reference voltage signal node Q2 are different, the output signals are different, the current corresponding to the fingerprint voltage signal node Q1 is the fingerprint current signal Ifp, and the current corresponding to the reference voltage signal node Q2 is the reference current signal Icom. Because fingerprint voltage signal node Q1 and reference voltage signal node Q2 all have the capacitive coupling effect because first electric capacity C1 and second electric capacity C2, consequently fingerprint voltage signal node Q1 and reference voltage signal node Q2 correspond the electric current of output respectively and do and deduct, the capacitive coupling effect just can be eliminated to can promote the SNR of output fingerprint identification signal, the interference killing feature of reinforcing circuit is favorable to promoting the detection effect of fingerprint identification circuit.
It is optional, first electric capacity C1 equals with second electric capacity C2's electric capacity, fingerprint identification unit 10 passes through the capacitive coupling effect of first electric capacity C1 and second electric capacity C2 that electric capacity equals with contrast unit 20, the electric potential of assurance fingerprint voltage signal node Q1 that can be more accurate and reference voltage signal node Q2's electric potential simultaneously drop to first magnitude of voltage M, further guaranteed equality of difference F, capacitive coupling effect just can be eliminated, thereby can promote the SNR of output fingerprint identification signal, the interference killing feature of reinforcing circuit, be favorable to promoting fingerprint identification circuit's detection effect.
Optionally, the fingerprint identification circuit further includes a differential amplification unit (not shown in fig. 7), the differential amplification unit may also be integrated in the driving chip, and the differential amplification unit reads the fingerprint identification signal according to a difference between the fingerprint current signal and the reference current signal, thereby completing the fingerprint identification operation.
The embodiment simultaneously outputs the reading interference signal and the fingerprint signal at the same time, and then deducts the fingerprint signal, because other variables may be introduced when the fingerprint signal is read at different time points, the embodiment simultaneously outputs the fingerprint current signal Ifp and the reference current signal Icom to eliminate the interference in time, so that the signal-to-noise ratio of the output fingerprint identification signal can be improved, the anti-interference capability of the circuit is enhanced, and the fingerprint identification effect is favorably improved. In the signal reading stage T3, the differential amplifying unit 40 obtains the fingerprint identification signal FRS after interference is removed according to the difference between the fingerprint current signal Ifp and the reference current signal Icom, so as to further improve the fingerprint identification effect.
In some optional embodiments, please refer to fig. 8, where fig. 8 is a schematic plane structure diagram of a display panel according to an embodiment of the present invention, and the display panel 111 according to the embodiment includes the fingerprint identification circuit 000 according to the embodiment of the present invention (for clearly and schematically understanding the technical solution of the embodiment, fig. 8 schematically illustrates the fingerprint identification circuit 000 as a frame structure with transparency filling disposed in the display panel 111, it can be understood that, in actual implementation, the fingerprint identification circuit 000 is a circuit connection structure). The display panel 111 provided in the embodiment of the present invention has the beneficial effect of the fingerprint identification circuit 000 provided in the embodiment of the present invention, and specific descriptions of the fingerprint identification circuit in the above embodiments may be specifically referred to, and this embodiment is not described herein again.
It should be noted that fig. 8 of the present embodiment only schematically illustrates a structure of the display panel 111 related to the technical solution of the present embodiment, and it can be understood that the display panel 111 not only includes the structure illustrated in fig. 8, but also includes other structures for implementing display and fingerprint identification functions, such as scan lines, data lines, pixel units, and other signal traces, which can be understood according to the description of the display panel in the prior art, and no repeated description is provided in the present embodiment.
In some alternative embodiments, please refer to fig. 8-12 continuously, fig. 9 is a schematic diagram of a planar structure of the fingerprint identification circuit in fig. 8 in the display panel, fig. 10 is a schematic diagram of another planar structure of the fingerprint identification circuit in fig. 8 in the display panel, fig. 11 is a schematic diagram of another planar structure of the fingerprint identification circuit in fig. 8 in the display panel, and fig. 12 is a schematic diagram of another planar structure of the fingerprint identification circuit in fig. 8 in the display panel (for clarity, fig. 9-12 only illustrate structures related to the fingerprint identification circuit, and other structures of the display panel can refer to fig. 8).
Referring to fig. 8 and 9, in an embodiment of the present invention, the display panel 111 further includes: a display area AA and a non-display area NA disposed around the display area AA; the display panel comprises a plurality of scanning lines G arranged along a second direction Y and extending along a first direction X, a plurality of data lines S arranged along the first direction X and extending along the second direction Y, and a plurality of pixel units 50 arranged in an array, wherein each pixel unit 50 comprises a plurality of sub-pixels 501, and the scanning lines G and the data lines S are crossed and insulated to define a region where the sub-pixels 501 are located; along the second direction Y, the plurality of pixel units 50 form a plurality of pixel rows 50H; the reset circuit comprises a plurality of reset signal lines Lrst, a plurality of reference voltage signal lines Lref and a plurality of input control signal lines Lsel, wherein the reset signal lines Lrst are electrically connected to a reset signal end Rst, the reference voltage signal lines Lref are electrically connected to a reference voltage input end Ref, and the input control signal lines Lsel are electrically connected to an input control signal end Sel; the fingerprint current detection circuit comprises a plurality of reference current output signal lines Lcom, a plurality of fingerprint current output signal lines Lfp and a plurality of current signal input signal lines Lsig, wherein the reference current output signal lines Lcom are electrically connected to a reference current output end I2, the fingerprint current output signal lines Lfp are electrically connected to a fingerprint current output end I1, and the current signal input signal lines Lsig are electrically connected to a current signal input end sig; at least a part of the fingerprint identification circuit 000 is located in the display area AA, and the rest of the fingerprint identification circuit 000 is located in the non-display area NA.
The embodiment further explains a structure that the display panel 111 can realize the display function and the fingerprint identification function, and by disposing part of the fingerprint identification circuit 000 in the display area AA and the rest of the fingerprint identification circuit 000 in the non-display area NA, the circuit layout of the display area AA can be simplified, and the aperture ratio of the display panel can be improved. It should be noted that, in this embodiment, only a portion of the fingerprint identification circuit 000 is disposed in the display area AA, and the remaining portion of the fingerprint identification circuit 000 is disposed in the non-display area NA, and in the specific implementation, which unit of the fingerprint identification unit 10, the comparison unit 20, and the selection unit 30 of the fingerprint identification circuit 000 is disposed in the display area AA, and which unit is disposed in the non-display area NA may be set according to actual requirements.
Optionally, as shown in fig. 9, each pixel unit 50 is correspondingly provided with one fingerprint identification unit 10 and one selection unit 30, each pixel row 50H is correspondingly provided with one comparison unit 20, the fingerprint identification unit 10 and the selection unit 30 are located in the display area AA, the comparison unit 20 is located in the non-display area NA, and the same pixel row 50H is electrically connected to the same comparison unit 20.
The reset signal line Lrst, the reference voltage signal line Lref, and the input control signal line Lsel are arranged along the second direction Y and extend along the first direction X, and the reference current output signal line Lcom, the fingerprint current output signal line Lfp, and the current signal input signal line Lsig are arranged along the first direction X and extend along the second direction Y.
Each pixel unit 50 of the present embodiment includes a fingerprint identification unit 10 and a selection unit 30, and each pixel row 50H shares a comparison unit 20, so that the circuit layout of the display area AA can be simplified, and the aperture ratio of the display panel can be improved.
Optionally, as shown in fig. 10, each pixel unit 50 is correspondingly provided with one fingerprint identification unit 10, each pixel row 50H is correspondingly provided with one comparison unit 20 and one selection unit 30, the fingerprint identification unit 10 is located in the display area AA, the comparison unit 20 and the selection unit 30 are located in the non-display area NA, and the same pixel row 50H is electrically connected to the same comparison unit 20 and the same selection unit 30.
The reset signal line Lrst and the reference voltage signal line Lref are arranged along the second direction Y and extend along the first direction X, and the input control signal line Lsel, the reference current output signal line Lcom, the fingerprint current output signal line Lfp, and the current signal input signal line Lsig are arranged along the first direction X and extend along the second direction Y.
Each pixel unit 50 of this embodiment only includes one fingerprint identification unit 10, the selection unit 30 and the comparison unit 20 are both disposed in the non-display area NA (the same position of the scanning drive circuit of the pixel unit) for sharing, and the same pixel row 50H shares the same comparison unit 20 and the same selection unit 30, so that the circuit layout of the display area AA can be further simplified, and the aperture ratio of the display panel is improved.
Optionally, as shown in fig. 11, each pixel unit 50 is correspondingly provided with one fingerprint identification unit 10 and one selection unit 30, all the pixel units 50 of the display panel 111 share one comparison unit 20, the fingerprint identification unit 10 and the selection unit 30 are located in the display area AA, the comparison unit 20 is located in the non-display area NA, and each pixel row 50H is electrically connected to the same comparison unit 20.
The input control signal lines Lsel are arranged along the second direction Y and extend along the first direction X, and the reference current output signal lines Lcom, the fingerprint current output signal lines Lfp, and the current signal input signal lines Lsig are arranged along the first direction X and extend along the second direction Y. At this time, the reset signal line Lrst and the reference voltage signal line Lref are partially arranged in the second direction Y and extend in the first direction X, and the other part is arranged in the first direction X and extend in the second direction Y.
Each pixel unit 50 of the present embodiment includes a fingerprint identification unit 10 and a selection unit 30, and all the pixel units 50 of the display panel 111 share one comparison unit 20, so that the circuit layout of the display area AA can be further simplified, the aperture ratio of the display panel is improved, the frame of the display panel is reduced, and the realization of a narrow frame is facilitated.
Optionally, as shown in fig. 12, each pixel unit 50 is correspondingly provided with one fingerprint identification unit 10, all the pixel units 50 of the display panel 111 share one comparison unit 20 and one selection unit 30, the fingerprint identification unit 10 is located in the display area AA, the comparison unit 20 and the selection unit 30 are located in the non-display area NA, and each pixel row 50H is electrically connected to the same comparison unit 20 and the same selection unit 30.
Each pixel unit 50 of this embodiment only includes one fingerprint identification unit 10, and all pixel units 50 of the display panel 111 share one comparison unit 20 and one selection unit 30, so that the circuit layout of the display area AA can be further simplified, the aperture ratio of the display panel is improved, the frame of the display panel is reduced, and the implementation of a narrow frame is facilitated.
In some optional embodiments, please refer to fig. 13, fig. 13 is a schematic structural diagram of a display device 1111 provided in the embodiment of the present invention, and the display device 1111 provided in the embodiment of the present invention includes the display panel 000 provided in the above embodiment of the present invention. The embodiment in fig. 13 only takes a mobile phone as an example to describe the display device 1111, it should be understood that the display device 1111 provided in the embodiment of the present invention may be other display devices 1111 with a display function, such as a computer, a television, and a vehicle-mounted display device, and the present invention is not limited thereto. The display device 1111 provided in the embodiment of the present invention has the beneficial effects of the display panel and the fingerprint identification circuit provided in the embodiment of the present invention, and specific descriptions of the display panel and the fingerprint identification circuit in the above embodiments may be specifically referred to, and are not repeated herein.
In some optional embodiments, referring to fig. 14, fig. 14 is a schematic plane structure diagram of another display device provided in the embodiments of the present invention (for clarity, fig. 14 only illustrates structures related to a fingerprint identification circuit and a differential amplifying unit, and other structures of the display device are not illustrated), in which the display device 1111 further includes a differential amplifying unit 40, and both the fingerprint current output signal line Lfp and the reference current output signal line Lcom are electrically connected to the differential amplifying unit 40.
The present embodiment further explains that the display device 1111 further includes a differential amplifying unit 40, and in the signal reading phase T3, the differential amplifying unit 40 obtains the fingerprint identification signal after interference is removed according to the difference between the fingerprint current signal Ifp output by the fingerprint current output signal line Lfp and the reference current signal Icom output by the reference current output signal line Lcom, so as to further improve the fingerprint identification effect. Optionally, in practical implementation, the differential amplifying unit 40 may be integrated in the driving chip 60 (as shown in fig. 13), so as to be beneficial to implementing a narrow frame of the display device, and the driving chip 60 may also be used to read the fingerprint detection signal of the fingerprint identification circuit.
According to the embodiment, the fingerprint identification circuit, the working method thereof, the display panel and the display device provided by the invention at least realize the following beneficial effects:
in the fingerprint identification circuit, the comparison unit plays a comparison role, which is equivalent to background or bottom noise, and the identification signal-to-noise ratio of the fingerprint identification circuit can be improved by deducting the background or bottom noise signal of the comparison unit through the fingerprint signal. The selection unit is a switch for controlling the output of the fingerprint identification signal, and can control the whole fingerprint identification circuit to be opened line by line and read the fingerprint identification signal line by line. The input current signal input by the current signal input end connected with the selection unit passes through the selection unit and then generates two signals of a fingerprint current signal and a reference current signal at the same time, and then the difference of the two signals is compared to judge whether the fingerprint is a valley or a ridge. The fingerprint current signal and the reference current signal are output simultaneously, namely the read interference signal and the fingerprint signal are output at the same time and are deducted, so that the situation that other variables are possibly introduced when the fingerprint signal is read at different time points is avoided, the interference in time can be eliminated, the signal-to-noise ratio of the output fingerprint identification signal is improved, the anti-interference capability of a circuit is enhanced, and the fingerprint identification effect is favorably improved.
Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustrative purposes only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.
Claims (16)
1. A fingerprint identification circuit, comprising:
the fingerprint identification unit comprises a reset signal input end, a reference voltage input end and a grounding voltage input end, the fingerprint identification unit is connected with a fingerprint voltage signal node, and the fingerprint identification unit provides a fingerprint voltage signal to the fingerprint voltage signal node;
the comparison unit comprises the reset signal input end, the reference voltage input end and the grounding voltage input end, is connected with a reference voltage signal node, and provides a reference voltage signal to the reference voltage signal node;
the fingerprint current detection device comprises a selection unit, a fingerprint current detection unit and a fingerprint detection unit, wherein the selection unit comprises a current signal input end, an input control signal end, a fingerprint current output end and a reference current output end, the selection unit is connected with a fingerprint voltage signal node and a reference voltage signal node, and the selection unit provides a fingerprint current signal to the fingerprint current output end and also provides a reference current signal to the reference current output end; and reading a fingerprint identification signal according to the difference value of the fingerprint current signal and the reference current signal.
2. The fingerprint identification circuit of claim 1, wherein the reset signal input provides a reset signal, the reference voltage input provides a reference voltage, and the ground voltage input provides a ground signal.
3. The circuit of claim 1, further comprising a differential amplifier unit, wherein the differential amplifier unit reads the fingerprint identification signal according to a difference between the fingerprint current signal and the reference current signal.
4. The fingerprint identification circuit of claim 1, wherein the fingerprint identification unit comprises a first transistor, a photodiode, a first capacitor;
the control end of the first transistor is connected with the reset signal input end, the first end of the first transistor is connected with the reference voltage input end, and the second end of the first transistor is connected with the fingerprint voltage signal node;
a first pole of the photosensitive diode is connected with the fingerprint voltage signal node, and a second pole of the photosensitive diode is connected with the grounding voltage input end;
the first end of the first capacitor is connected with the fingerprint voltage signal node, and the second end of the first capacitor is connected with the grounding voltage input end.
5. The fingerprint identification circuit of claim 1, wherein the comparison unit comprises a second transistor and a second capacitor;
the control end of the second transistor is connected with the reset signal input end, the first end of the second transistor is connected with the reference voltage input end, and the second end of the second transistor is connected with the reference voltage signal node;
the first end of the second capacitor is connected with the reference voltage signal node, and the second end of the second capacitor is connected with the grounding voltage input end.
6. The fingerprint identification circuit of claim 1, wherein the selection unit comprises a third transistor, a fourth transistor, a fifth transistor;
a control end of the third transistor is connected with the fingerprint voltage signal node, a first end of the third transistor is connected with a first end of the fifth transistor, and a second end of the third transistor is connected with the fingerprint current output end;
a control end of the fourth transistor is connected with the reference voltage signal node, a first end of the fourth transistor is connected with a first end of the fifth transistor, and a second end of the fourth transistor is connected with the reference current output end;
and the control end of the fifth transistor is connected with the input control signal end, and the second end of the fifth transistor is connected with the current signal input end.
7. An operating method of a fingerprint recognition circuit, wherein the operating method is used for the fingerprint recognition circuit of claim 1 to perform fingerprint recognition operation;
the working method at least comprises the following steps: a signal resetting stage, a signal detecting stage and a signal reading stage;
in the signal resetting phase, a high level is provided to the reset signal input end and a reference voltage is provided to the reference voltage input end, and the fingerprint identification unit and the comparison unit respond to the high level of the reset signal input end to provide the reference voltage to the fingerprint voltage signal node and provide the reference voltage to the reference voltage signal node; and providing a low level to the reset signal input end, wherein the potential of the fingerprint voltage signal node and the potential of the reference voltage signal node simultaneously drop to a first voltage value;
in the signal detection stage, the fingerprint identification unit performs light sensing fingerprint identification work, and the potential of the fingerprint voltage signal node continuously drops to a second voltage value;
in the signal reading stage, a high level is provided for the input control signal terminal, the selection unit responds to the high level of the input control signal terminal, the current signal input terminal provides input current, and the selection unit provides the fingerprint current signal to the fingerprint current output terminal according to the input current and the second voltage value; meanwhile, the selection unit provides the reference current signal to the reference current output end according to the input current and the first voltage value; and reading the difference value between the fingerprint current signal and the reference current signal, and obtaining the fingerprint identification signal according to the difference value to finish the fingerprint identification work.
8. The method of claim 7,
the fingerprint identification unit comprises a first transistor, a photosensitive diode and a first capacitor; the control end of the first transistor is connected with the reset signal input end, the first end of the first transistor is connected with the reference voltage input end, and the second end of the first transistor is connected with the fingerprint voltage signal node; the first pole of the photosensitive diode is connected with the fingerprint voltage signal node, and the second pole of the photosensitive diode is connected with the grounding voltage input end; the first end of the first capacitor is connected with the fingerprint voltage signal node, and the second end of the first capacitor is connected with the grounding voltage input end;
the comparison unit comprises a second transistor and a second capacitor; a control end of the second transistor is connected with the reset signal input end, a first end of the second transistor is connected with the reference voltage input end, and a second end of the second transistor is connected with the reference voltage signal node; the first end of the second capacitor is connected with the reference voltage signal node, and the second end of the second capacitor is connected with the grounding voltage input end;
the selection unit comprises a third transistor, a fourth transistor and a fifth transistor; a control end of the third transistor is connected with the fingerprint voltage signal node, a first end of the third transistor is connected with a first end of the fifth transistor, and a second end of the third transistor is connected with the fingerprint current output end; a control end of the fourth transistor is connected with the reference voltage signal node, a first end of the fourth transistor is connected with a first end of the fifth transistor, and a second end of the fourth transistor is connected with the reference current output end; the control end of the fifth transistor is connected with the input control signal end, and the second end of the fifth transistor is connected with the current signal input end;
during the signal reset phase, providing a high level to the reset signal input and providing the reference voltage to the reference voltage input, the first transistor and the second transistor being in a conducting state in response to the high level of the reset signal input, the reference voltage being transmitted to the fingerprint voltage signal node through the first transistor, the reference voltage being transmitted to the reference voltage signal node through the second transistor; and, providing a low level to the reset signal input terminal, the first transistor and the second transistor being in an off state in response to the low level of the reset signal input terminal, the potential of the fingerprint voltage signal node and the potential of the reference voltage signal node simultaneously dropping to the first voltage value;
in the signal detection stage, the photosensitive diode performs photosensitive fingerprint identification, and the potential of the fingerprint voltage signal node continuously drops to a second voltage value;
in the signal reading phase, a high level is provided to the input control signal terminal, the fifth transistor is in a conducting state in response to the high level of the input control signal terminal, the input current provided by the current signal input terminal is transmitted to the first terminal of the third transistor and the first terminal of the fourth transistor through the fifth transistor respectively, the third transistor is in a conducting state in response to the second voltage value, and the third transistor provides the fingerprint current signal to the fingerprint current output terminal according to the input current and the second voltage value; the fourth transistor responds to the first voltage value and is in a conducting state, and the fourth transistor provides the reference current signal to the reference current output end according to the input current and the first voltage value;
the fingerprint identification circuit further comprises a differential amplification unit, and the differential amplification unit reads the fingerprint identification signal according to the difference value of the fingerprint current signal and the reference current signal to finish fingerprint identification work.
9. A display panel characterized in that it comprises a fingerprint recognition circuit according to claim 1.
10. The display panel according to claim 9, characterized in that the display panel further comprises:
a display area and a non-display area disposed around the display area;
the pixel array comprises a plurality of scanning lines arranged along a second direction and extending along a first direction, a plurality of data lines arranged along the first direction and extending along the second direction, and a plurality of pixel units arranged in an array, wherein each pixel unit comprises a plurality of sub-pixels, and the scanning lines and the data lines are crossed and insulated to define an area where the sub-pixels are located; along the second direction, a plurality of pixel units form a plurality of pixel rows;
the circuit comprises a plurality of reset signal lines, a plurality of reference voltage signal lines and a plurality of input control signal lines, wherein the reset signal lines are electrically connected with a reset signal end, the reference voltage signal lines are electrically connected with a reference voltage input end, and the input control signal lines are electrically connected with an input control signal end;
a plurality of reference current output signal lines, a plurality of fingerprint current output signal lines, a plurality of current signal input signal lines, the reference current output signal lines electrically connected to the reference current output terminals, the fingerprint current output signal line is electrically connected with the fingerprint current output end, and the current signal input signal line is electrically connected with the current signal input end;
at least part of the fingerprint identification circuit is positioned in the display area, and the rest part of the fingerprint identification circuit is positioned in the non-display area.
11. The display panel according to claim 10,
each pixel unit is correspondingly provided with one fingerprint identification unit and one selection unit, each pixel row is correspondingly provided with one comparison unit, the fingerprint identification unit and the selection unit are positioned in the display area, the comparison units are positioned in the non-display area, and the same pixel row is electrically connected with the same comparison unit;
the reset signal line, the reference voltage signal line and the input control signal line are arranged along the second direction and extend along the first direction, and the reference current output signal line, the fingerprint current output signal line and the current signal input signal line are arranged along the first direction and extend along the second direction.
12. The display panel according to claim 10,
each pixel unit is correspondingly provided with one fingerprint identification unit, each pixel row is correspondingly provided with one comparison unit and one selection unit, the fingerprint identification unit is positioned in the display area, the comparison unit and the selection unit are positioned in the non-display area, and the same pixel row is electrically connected with the same comparison unit and the same selection unit;
the reset signal line and the reference voltage signal line are arranged along the second direction and extend along the first direction, and the input control signal line, the reference current output signal line, the fingerprint current output signal line and the current signal input signal line are arranged along the first direction and extend along the second direction.
13. The display panel according to claim 10,
each pixel unit is correspondingly provided with one fingerprint identification unit and one selection unit, all the pixel units of the display panel share one comparison unit, the fingerprint identification units and the selection units are positioned in the display area, the comparison units are positioned in the non-display area, and each pixel row is electrically connected with the same comparison unit.
14. The display panel according to claim 10,
each pixel unit is correspondingly provided with one fingerprint identification unit, all the pixel units of the display panel share one comparison unit and one selection unit, the fingerprint identification unit is positioned in the display area, the comparison unit and the selection unit are positioned in the non-display area, and each pixel row is electrically connected with the same comparison unit and the same selection unit.
15. A display device characterized by comprising the display panel according to any one of claims 9 to 14.
16. The display device according to claim 15, further comprising a differential amplification unit, wherein the fingerprint current output signal line and the reference current output signal line are each electrically connected to the differential amplification unit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911307055.6A CN110956162B (en) | 2019-12-18 | 2019-12-18 | Fingerprint identification circuit, working method thereof, display panel and display device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911307055.6A CN110956162B (en) | 2019-12-18 | 2019-12-18 | Fingerprint identification circuit, working method thereof, display panel and display device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110956162A CN110956162A (en) | 2020-04-03 |
| CN110956162B true CN110956162B (en) | 2022-10-14 |
Family
ID=69982493
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911307055.6A Active CN110956162B (en) | 2019-12-18 | 2019-12-18 | Fingerprint identification circuit, working method thereof, display panel and display device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110956162B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111738121B (en) * | 2020-06-15 | 2024-03-29 | 武汉华星光电技术有限公司 | Fingerprint reading circuit and display panel thereof |
| CN112599064B (en) * | 2020-12-03 | 2022-09-09 | 深圳市华星光电半导体显示技术有限公司 | Display device and denoising method thereof |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3082141B1 (en) * | 1999-06-04 | 2000-08-28 | 日本電信電話株式会社 | Sensor circuit for surface shape recognition |
| CN101051258B (en) * | 2007-05-22 | 2013-03-13 | 中电通信科技有限责任公司 | Finger print navigation method and finger print navigation system |
| KR102002081B1 (en) * | 2015-06-19 | 2019-07-22 | 크루셜텍 (주) | Fingerprint detecting apparatus and driving method thereof |
| WO2016204416A1 (en) * | 2015-06-19 | 2016-12-22 | 크루셜텍(주) | Fingerprint detection device and driving method therefor |
| CN105512650B (en) * | 2016-01-26 | 2019-10-25 | 湖南融创微电子有限公司 | A kind of capacitance type fingerprint detection circuit, sensor and equipment |
| CN107039002B (en) * | 2017-06-05 | 2019-09-06 | 京东方科技集团股份有限公司 | A kind of pixel circuit and display panel |
-
2019
- 2019-12-18 CN CN201911307055.6A patent/CN110956162B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN110956162A (en) | 2020-04-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108280432B (en) | Fingerprint identification detection circuit, driving method thereof and display device | |
| CN107958243B (en) | Active fingerprint identification pixel circuit, driving method and display panel | |
| JP6707624B2 (en) | Texture recognition display device and driving method | |
| CN110763336B (en) | Photodetection circuit, electronic device, and driving method | |
| CN110956162B (en) | Fingerprint identification circuit, working method thereof, display panel and display device | |
| US11308727B2 (en) | Fingerprint detection device and fingerprint detection method | |
| US11620848B2 (en) | Detection circuit, skin print recognition device and driving method | |
| CN110008860B (en) | Fingerprint identification framework and touch panel | |
| CN109298804B (en) | Touch circuit and driving method thereof, touch substrate and display device | |
| CN111428697B (en) | Optical sensor circuit, detector, imaging system, sensor, and display panel | |
| CN110796983A (en) | Display device and driving method thereof | |
| CN108024075A (en) | Global shutter high dynamic range pixel and image sensor | |
| WO2003049017A1 (en) | Method, sensing device and optical pointing device including a sensing device for comparing light intensity between pixels | |
| TWI764161B (en) | light detection device | |
| US6891143B2 (en) | Photo-sensor array with pixel-level signal comparison | |
| CN111027384B (en) | Fingerprint identification detection circuit, detection method and display device | |
| JPS5858716B2 (en) | Self-scanning light sensing circuit | |
| TWI360644B (en) | Photo sensor for a display device | |
| US11200399B1 (en) | Display panel and driving method of display panel | |
| CN112597805B (en) | Display panel, display device and working method thereof | |
| CN112287845B (en) | Display panel and display device | |
| CN205900069U (en) | Line discernment display device | |
| WO2022163710A1 (en) | Detection device | |
| CN112699853B (en) | Fingerprint identification circuit, driving method thereof and fingerprint identification equipment | |
| US20230100833A1 (en) | Fingerprint readout circuit and display panel thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |