Fingerprint sensing device, fingerprint readout circuit and touch display panel

Abstract

A fingerprint sensing device includes a plurality of fingerprint sensors and a fingerprint readout circuit. The fingerprint sensors can be configured to operate in a fingerprint sensing cycle. The fingerprint readout circuit can be coupled to the plurality of fingerprint sensors via a plurality of sense lines. The fingerprint readout circuit can be configured to control the fingerprint sensors to operate in the fingerprint sensing cycle. The fingerprint sensing cycle includes an initialization period, an exposure period, and a readout period. A voltage of a reset node in each of the fingerprint sensors is reset to a first voltage in a reset period before the fingerprint sensing cycle begins. The voltage of the reset node in each of the fingerprint sensors is initialized to an initial voltage in the initialization period. The initial voltage is different from the first voltage.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to fingerprint sensing; in particular, the present disclosure relates to a fingerprint sensing device, a fingerprint readout circuit, and a touch display panel. BACKGROUND

[0002] Fingerprint recognition is a commonly used security protection technique. To reduce the size of electronic products and increase convenience, optical fingerprint sensor arrays are often integrated in touch display panels. However, the quality of captured fingerprint image data can be unstable due to in-display fingerprint sensor structures, which can increase the false rejection rate (FRR) and / or the false acceptance rate (FAR) of fingerprint recognition. SUMMARY

[0003] The present disclosure relates to a fingerprint sensing device, a fingerprint readout circuit, and a touch display panel, in particular, a fingerprint sensing device, a fingerprint readout circuit, and a touch display panel embedded with in-display fingerprint sensor structures to improve the stability of fingerprint image quality.

[0004] In the present disclosure, the fingerprint sensing device includes a plurality of fingerprint sensors and a fingerprint readout circuit. The fingerprint sensors can be configured to operate in a fingerprint sensing cycle. The fingerprint readout circuit can be coupled to the plurality of fingerprint sensors via a plurality of sensing lines. The fingerprint readout circuit can be configured to control the fingerprint sensors to operate in the fingerprint sensing cycle. The fingerprint sensing cycle includes an initialization period, an exposure period, and a readout period. A voltage of a reset node in each of the fingerprint sensors is reset to a first voltage in a reset period before the fingerprint sensing cycle starts. The voltage of the reset node in each fingerprint sensor is initialized to an initial voltage in the initialization period. The initial voltage is different from the first voltage.

[0005] In the present disclosure, the fingerprint readout circuit can be configured to be coupled to a touch display panel. The touch display panel can include a plurality of fingerprint sensors arranged in a sensor array and an array gate circuit. The fingerprint readout circuit can be coupled to the plurality of fingerprint sensors via a plurality of sense lines. The fingerprint readout circuit can be coupled to the array gate circuit. The fingerprint readout circuit can be configured to output at least one start pulse signal and at least one clock signal to control the array gate circuit to output a reset signal and a select signal. The reset signal and the select signal can be configured to control at least one fingerprint sensing region of the fingerprint sensors arranged in the sensor array to operate in a fingerprint sensing cycle. The fingerprint sensing cycle can include an initialization period, an exposure period, and a readout period. According to the reset signal, a voltage of a reset node in each of the fingerprint sensors can be reset to a first voltage in a reset period before the fingerprint sensing cycle starts. The voltage of the reset node in each fingerprint sensor can be initialized to an initial voltage in the initialization period. The initial voltage is different from the first voltage.

[0006] In the present disclosure, the touch display panel can include a plurality of sense lines, a plurality of fingerprint sensors. The plurality of fingerprint sensors can be configured to operate in a fingerprint sensing cycle. The plurality of fingerprint sensors can be coupled to a fingerprint readout circuit via the sense lines. The fingerprint sensing cycle includes an initialization period, an exposure period, and a readout period. A voltage of a reset node in each of the fingerprint sensors can be reset to a first voltage in a reset period before the fingerprint sensing cycle starts. The voltage of the reset node in each fingerprint sensor can be initialized to an initial voltage in the initialization period. The initial voltage is different from the first voltage.

[0007] Based on the above, the fingerprint sensing device, the fingerprint readout circuit, and the touch display panel according to the present disclosure, a reset period is arranged before a fingerprint sensing cycle to reset the voltage of a reset node of a fingerprint sensor. Therefore, the quality of a fingerprint image becomes more stable. As a result, the false rejection rate (FRR) and / or the false acceptance rate (FAR) of fingerprint recognition can be reduced and the accuracy of fingerprint recognition can be improved.

[0008] In order to make the above more comprehensible, several embodiments accompanied by drawings will be described in detail below. BRIEF DESCRIPTION OF DRAWINGS

[0009] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain principles of the present disclosure.

[0010] Figure 1is a schematic diagram of a fingerprint sensing device according to one embodiment of the present disclosure.

[0011] Figure 2 is a schematic diagram of a fingerprint sensor according to one embodiment of the present disclosure.

[0012] Figure 3 is a schematic timing diagram of a fingerprint sensor according to one embodiment of the present disclosure.

[0013] Figure 4 is a schematic timing diagram of a fingerprint sensor according to one embodiment of the present disclosure.

[0014] Figure 5 is a schematic diagram of a fingerprint sensor array according to one embodiment of the present disclosure.

[0015] Figure 6 is a schematic timing diagram of a fingerprint sensor array according to one embodiment of the present disclosure.

[0016] Figure 7 is a schematic timing diagram of a fingerprint sensor array according to one embodiment of the present disclosure.

[0017] Figure 8 is a schematic diagram of a touch display panel including a fingerprint sensor array according to one embodiment of the present disclosure.

[0018] Figure 9 is a schematic timing diagram of a touch display panel including a fingerprint sensor array according to a first embodiment of the present disclosure.

[0019] Figure 10 is a schematic timing diagram of a touch display panel including a fingerprint sensor array according to a second embodiment of the present disclosure.

[0020] Figure 11 is a schematic timing diagram of a touch display panel including a fingerprint sensor array according to a third embodiment of the present disclosure.

[0021] Figure 12 is a schematic timing diagram of a touch display panel including a fingerprint sensor array according to a fourth embodiment of the present disclosure.

[0022] Figure 13 is a schematic timing diagram of a touch display panel including a fingerprint sensor array according to a fifth embodiment of the present disclosure.

[0023] Figure 14 is a schematic timing diagram of a touch display panel including a fingerprint sensor array according to a sixth embodiment of the present disclosure.

[0024] Figure 15 is a schematic diagram of a fingerprint readout circuit according to one embodiment of the present disclosure.

[0025] Figure 16 is a schematic view of a touch display panel according to one embodiment of the present disclosure.

[0026] [Explanation of symbols]

[0027] 100: Fingerprint sensing device

[0028] 110, 200, 510, 810, 1521, 1610: Fingerprint sensor

[0029] 120, 1500, 1630: Fingerprint readout circuit

[0030] 130, 1540, 1620, SO1, SO2, SOn: Sensing line

[0031] 300, 400, 600, 700, 900, 1000, 1100, 1200, 1300, 1400: Timing chart

[0032] 500: Fingerprint sensor array

[0033] 800, 1510, 1600: Touch display panel

[0034] 820: Pixel

[0035] 1520: Sensor array

[0036] 1530: On-array gate circuit

[0037] C1: First capacitor

[0038] C2: Second capacitor

[0039] C3: Third capacitor

[0040] CLK: Clock signal

[0041] Cycle1: First fingerprint sensing cycle

[0042] Cycle2: Second fingerprint sensing cycle

[0043] CycleN: Nth fingerprint sensing cycle

[0044] DP+TP: Touch display frame period (frame period)

[0045] F601, F602, F603, F701, F702, F901, F902, F903, F904, F905, F906, F907, F1001, F1002, F1003, F1004, F1005, F1006, F1007, F1008, F1009, F1010, F1011, F1101, F1102, F1103, F1104, F1105, F1106, F1107, F1108, F1109, F1110, F1111, F1112, F1113, F1201, F1202, F1203, F1204, F1205, F1206, F1207, F1208, F1301, F1302, F1303, F1304, F1305, F1401, F1402, F1403, F1404, F1405, F1406, F1407: frame period

[0046] FPR: fingerprint frame period

[0047] FZ1, FZ2, FZ3, FZ4: fingerprint sensing zone

[0048] GD1, GD2, GDn: display scan line

[0049] GS1, GS2, GSn: reset line

[0050] M1: reset switch

[0051] M2: source follower

[0052] M3: selection switch

[0053] M4: pixel switch

[0054] Output, T1, Tn, TP1, TPn: output terminal

[0055] P: reset node

[0056] P_EXP: exposure period

[0057] P_INIT: initialization period

[0058] P_READ: readout period

[0059] P_RST: reset period

[0060] Row1_M1, Row1_M3, Row2_M1, Row2_M3, RowN_M1, RowN_M3, VM1, VM3, Vsig: voltage signal

[0061] RST: reset signal

[0062] S1: light sensor

[0063] SD1, SD2, SDn: display data line

[0064] SEL: selection signal

[0065] SF1, SF2, SFn: fingerprint scan line

[0066] SIM: control signal

[0067] STV, STV1, STV2, STV3, STV4: start pulse signal

[0068] Sync: mode signal

[0069] t301, t302, t303, t304, t305, t306, t401, t401a, t401b, t402, t403, t404, t405, t406, t601, t602, t603, t604, t701, t702, t703, t901, t902, t903, t904, t905, t906, t907, t908, t1001, t1002, t1003, t1004, t1005, t1006, t1007, t1008, t1009, t1010, t1011, t1012, t1101, t1102, t1103, t1104, t1105, t1106, t1107, t1108, t1109, t1110, t1111, t1112, t1113, t1114, t1201, t1202, t1203, t1204, t1205, t1206, t1207, t1208, t1209, t1301, t1302, t1303, t1304, t1305, t1306, t1401, t1402, t1403, t1404, t1405, t1406, t1407, t1408: time

[0070] Vbias: bias voltage

[0071] VDD: operating voltage

[0072] VP: voltage

[0073] VR: residual voltage

[0074] ΔV: voltage change DETAILED DESCRIPTION

[0075] Reference will now be made in detail embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings and the specification to refer to the same or like components.

[0076] Throughout the specification and the annexed claims of this disclosure, certain terms are used to refer to particular components. Those of ordinary skill in the art will understand that electronic device manufacturers can use different names to refer to the same component. No distinction is intended between terms used to refer to the same component having different names. In the following description and in the claims, words like "comprise" and "include" are open-ended terms and should be interpreted as "including but not limited to...".

[0077] The term "coupling (or connection)" used throughout the specification of this application (including the annexed claims) can refer to any direct or indirect connection. For example, if the text states that a first device is coupled (or connected) to a second device, it should be interpreted that the first device can be directly connected to the second device, or the first device can be indirectly connected to the second device through other devices or certain connection means. The terms "first", "second", and similar terms mentioned throughout the specification of this application (including the annexed claims) are only used to name discrete elements or to distinguish different embodiments or ranges. Therefore, the terms should not be considered as limiting the upper or lower limit of the number of elements and should not be used to limit the arrangement order of the elements. In addition, as far as possible, the same reference numbers of elements / components / steps are used to represent the same or similar parts in the drawings and embodiments. The related descriptions of the elements / components / steps can be referred to each other using the same reference numbers or using the same terms.

[0078] It should be noted that in the following embodiments, the technical features of several different embodiments can be replaced, recombined, and mixed to complete other embodiments without departing from the spirit of the disclosure. As long as the features of each embodiment do not violate the spirit of the disclosure or conflict with each other, the embodiments can be arbitrarily mixed and used together.

[0079] Figure 1 is a schematic diagram of a fingerprint sensing device according to one embodiment of the disclosure. Referring to Figure 1The fingerprint sensing device 100 can comprise a plurality of fingerprint sensors 110 and a fingerprint readout circuit 120. The fingerprint sensors 110 can be configured to operate in a fingerprint sensing cycle. The fingerprint readout circuit 120 can be coupled to the plurality of fingerprint sensors 110 via a plurality of sensing lines 130. The fingerprint readout circuit 120 can be configured to control the fingerprint sensors 110 to operate in a fingerprint sensing cycle. The fingerprint sensing cycle comprises an initialization period, an exposure period, and a readout period. A voltage VP of a reset node P in each of the fingerprint sensors 110 is reset to a first voltage in a reset period before the start of the fingerprint sensing cycle. The voltage VP of the reset node P in each of the fingerprint sensors 110 is initialized to an initial voltage in the initialization period. The initial voltage is different from the first voltage.

[0080] In one embodiment, the reset node P is a node of a photosensor electrically coupled to the fingerprint sensor 110. The voltage VP of the reset node P is reset to the first voltage before the fingerprint sensing cycle, and thus, the fingerprint image quality becomes more stable, and thereby reduces the false rejection rate (FRR) and / or the false acceptance rate (FAR) of the fingerprint recognition.

[0081] Figure 2 is a schematic diagram of a fingerprint sensor according to one embodiment of the present disclosure. Referring to Figure 1 and Figure 2 , Figure 2 The fingerprint sensor 200 in Figure 1One embodiment of the fingerprint sensor 110 in FIG. 1, but the present disclosure is not limited thereto. The fingerprint sensor 200 can include a photosensor S1, a first capacitor C1, a reset switch M1, a source follower M2 (as a transistor), and a selection switch M3. The photosensor S1 can be configured to sense light in an exposure period. The photosensor S1 can include a first terminal and a second terminal. The first capacitor C1 can include a first terminal and a second terminal. The first terminal of the photosensor S1 and the first terminal of the first capacitor C1 can be electrically coupled to a reset node P. The second terminal of the photosensor S1 and the second terminal of the first capacitor C1 can be electrically coupled to a bias node to receive a bias voltage Vbias. The reset switch M1 can include a first terminal, a second terminal, and a control terminal. The source follower M2 can include a first terminal, a second terminal, and a control terminal. The selection switch M3 can include a first terminal, a second terminal, and a control terminal. The first terminal of the reset switch M1 and the gate (i.e., the control terminal) of the source follower M2 can be electrically coupled to the reset node P. The second terminal of the reset switch M1 and the first terminal of the source follower M2 can be electrically coupled to a power supply node to receive a voltage signal Vsig. The second terminal of the source follower M2 can be electrically coupled to the first terminal of the selection switch M3. The second terminal of the selection switch M3 can be configured to provide a sensed voltage at an output terminal Output as an output signal. When the source follower M2 is turned on, the voltage on the first terminal of the selection switch M3 follows the voltage of the reset node P.

[0082] In one embodiment, when the reset switch M1 is turned on, the reset node P is electrically coupled to the power supply node that is supplied with the voltage signal Vsig. The voltage signal Vsig remains at a first voltage in a reset period. The voltage signal Vsig remains at an initial voltage in an initialization period. In one embodiment, the first voltage can be 0 V, and the initial voltage can be an operating voltage VDD, but the present disclosure is not limited thereto. In this way, during the reset period, the voltage VP of the reset node P is reset to the first voltage, and during the initialization period, the voltage VP of the reset node P is initialized to the initial voltage. The voltage VP of the reset node P is reset to the first voltage before a fingerprint sensing cycle, and thus, when a plurality of fingerprint sensing cycles are performed, the quality of a fingerprint image becomes more stable, and thus, the false rejection rate (FRR) and / or the false acceptance rate (FAR) of fingerprint recognition is reduced.

[0083] In one embodiment, the fingerprint readout circuit 120 is configured to output the voltage signal Vsig to a touch display panel. That is, the fingerprint sensor can be integrated into the touch display panel. The degree of integration of the fingerprint sensing device and the touch display panel is thus improved.

[0084] Figure 3is a schematic timing diagram of a fingerprint sensor according to one embodiment of the present disclosure. Referring to Figures 1 to 3 In timing diagram 300, the voltage signal that controls the gate (i.e., control terminal) of reset switch Ml is denoted by VM1. The voltage signal that controls the gate (i.e., control terminal) of select switch M3 is denoted by VM3. The voltage VP of reset node P is denoted by VP. The initialization period of a fingerprint sensing cycle is denoted by P_INIT. The exposure period of a fingerprint sensing cycle is denoted by P_EXP. The readout period of a fingerprint sensing cycle is denoted by P_READ.

[0085] In one embodiment, fingerprint readout circuit 120 can read out the sensing voltage of each fingerprint sensor 110 via the corresponding sense line 130 in the readout period. The sensing voltage follows the voltage VP of reset node P. Fingerprint readout circuit 120 can generate the sensing result of each fingerprint sensor 110 based on the voltage change between the initial voltage and the sensing voltage.

[0086] Specifically, the initialization period P_INIT of a fingerprint sensing cycle is from time t301 to time t302. The exposure period P_EXP of a fingerprint sensing cycle is from time t302 to time t304. The readout period P_READ of a fingerprint sensing cycle is from t304 to time t305. As Figure 3 As illustrated in timing diagram 300, the exposure period P_EXP of a fingerprint sensing cycle is considered from the falling edge of voltage signal VM1 to the falling edge of voltage signal VM3; and on the other hand, the exposure period P_EXP of a fingerprint sensing cycle can be considered from the rising edge of voltage signal VM1 to the rising edge of voltage signal VM3. More accurately, with respect to each fingerprint sensor 110, the exposure period P_EXP of a fingerprint sensing cycle is considered from the time when the switch is turned on to the time when the switch is turned off. Figure 3The initialization operation and the readout operation illustrated in FIG. 10. An initialization period P_INIT of another fingerprint sensing cycle is from time t305 to time t306. At time t301, the voltage signal VM1 is configured to switch from low to high to turn on the reset switch M1. After M1 is turned on, the reset node P is electrically coupled to the power supply node to receive the voltage signal Vsig, and the voltage VP gradually increases toward the voltage signal Vsig by charging the first capacitor C1 during the initialization period P_INIT. In one embodiment, the voltage signal Vsig remains at an initial voltage in the initialization period P_INIT, and the initial voltage can be the operating voltage VDD, but the present disclosure is not limited thereto. At time t302, the voltage signal VM1 is configured to switch from high to low to turn off the reset switch M1. The voltage VP is initialized to the initial voltage (the operating voltage VDD), and the photosensor S1 is configured to sense light in an exposure period P_EXP. During the exposure period P_EXP, the voltage VP gradually decreases. At time t303, the voltage signal VM3 is configured to switch from low to high to turn on the select switch M3. After the select switch M3 is turned on, the sensing voltage follows the voltage VP of the reset node P. That is, the voltage VP is provided to the output terminal Output as the sensing voltage. The output terminal Output of the column of the fingerprint sensor 110 is coupled to the sensing line 130. The fingerprint readout circuit 120 reads out the sensing voltage of the fingerprint sensor 110 (in a column) via the sensing line 130. At time t304, the fingerprint readout circuit 120 generates a sensing result of the fingerprint sensor 110 based on a voltage variation AV between the initial voltage (the operating voltage VDD) and the sensing voltage. In other words, the voltage variation AV is a voltage difference between the initial voltage (the voltage VP of the reset node P can reach the initial voltage during the initialization period when M1 is turned on) and the voltage VP of the reset node P when M3 is turned off. In this way, the fingerprint sensing device 100 can implement the function of fingerprint recognition based on the sensing result.

[0087] Figure 4 is a schematic timing diagram of a fingerprint sensor according to one embodiment of the present disclosure. Referring to Figures 1 to 4In an ideal case, during the initialization period P INIT, the voltage VP of the reset node P is charged from 0V to the operating voltage VDD due to the reset switch being turned on for initialization of the fingerprint recognition. In one embodiment, there can be a residual voltage VR due to the residual charge in the first capacitor C1, and thus the stability of the read out fingerprint image is reduced, which can increase the false rejection rate (FRR) and / or the false acceptance rate (FAR) of the fingerprint recognition. To enhance the stability of the fingerprint image and reduce the false rejection rate (FRR) and / or the false acceptance rate (FAR) of the fingerprint recognition, a reset period P_RST can be set before the initialization period P INIT to clear the residual charge at the reset node P.

[0088] In one embodiment, in the timing diagram 400, the reset period P_RST is before the initialization period P INIT from time t401a to time t401b. At time t401a, the voltage signal VM1 is configured to switch from low to high to turn on the reset switch M1. After M1 is turned on, the reset node P is electrically coupled to the power supply node to receive the voltage signal Vsig, and the voltage VP gradually increases towards the voltage signal Vsig by charging the first capacitor C1 during the initialization period P INIT. In one embodiment, the voltage signal Vsig remains at the first voltage in the reset period P_RST, and the initial voltage can be 0V, but the present disclosure is not limited to this. At time t401b, the voltage signal VM1 is configured to switch from high to low to turn off the reset switch M1, and the voltage VP is reset to the reset voltage (0V) before the initialization period P INIT. The initialization period P INIT (time t401 to time t402), the exposure period P EXP (time t402 to time t404), and the read out period P READ (time t404 to time t405) can refer to the description of Figure 3 As the voltage VP is reset to the reset voltage (0V) before the initialization period P INIT, the effect of the residual voltage at the reset node P on the stability of the fingerprint image is reduced, and thus the quality of the fingerprint image becomes more stable. The false rejection rate (FRR) and / or the false acceptance rate (FAR) of the fingerprint recognition is reduced and the accuracy of the fingerprint recognition is improved.

[0089] Figure 5 is a schematic diagram of a fingerprint sensor array according to one embodiment of the present disclosure. Referring to Figure 1 and Figure 5 The fingerprint sensor array 500 can include a plurality of fingerprint sensors 510. The fingerprint sensor 510 can refer to the description of Figure 1The description of the fingerprint sensor 110 is shown and will not be repeated herein. In one embodiment, the fingerprint sensor array 500 can include n rows and n columns, but the present disclosure is not limited thereto. The fingerprint sensors 510 can be arranged at the intersection of each row and each column. The fingerprint sensors 510 can be coupled to a plurality of sense lines SO1 to SOn, a plurality of reset lines GS1 to GSn, and a plurality of fingerprint scan lines SF1 to SFn. The sense lines SO1 to SOn can be coupled to the fingerprint readout circuit 120. In one embodiment, the sense lines SO1 to SOn can be coupled to the fingerprint readout circuit 120 through a plurality of output terminals T1 to Tn, but the present disclosure is not limited thereto. The reset lines GS1 to GSn can be configured to provide a voltage signal to the gate of the reset switch M1 of the fingerprint sensor 510. The fingerprint scan lines SF1 to SFn can be configured to provide a voltage signal to the gate of the select switch M3 of the fingerprint sensor 510. In this way, the fingerprint sensor array 500 can integrate the plurality of fingerprint sensors 510 to achieve fingerprint recognition.

[0090] Figure 6 is a schematic timing diagram of a fingerprint sensor array according to one embodiment of the present disclosure. Referring to Figure 3 , Figure 5 and Figure 6 In the timing diagram 600, the operating voltage VDD of the voltage signal Vsig can be represented as VDD. Row1_M1 can represent the voltage signal of the gate of the reset switch M1 of the first row in the fingerprint sensor array 500. Row2_M1 can represent the voltage signal of the gate of the reset switch M1 of the second row in the fingerprint sensor array 500. RowN_M1 can represent the voltage signal of the gate of the reset switch M1 of the Nth row in the fingerprint sensor array 500. Row1_M3 can represent the voltage signal of the gate of the select switch M3 of the first row in the fingerprint sensor array 500. Row2_M3 can represent the voltage signal of the gate of the select switch M3 of the second row in the fingerprint sensor array 500. RowN_M3 can represent the voltage signal of the gate of the select switch M3 of the Nth row in the fingerprint sensor array 500.

[0091] In this embodiment, the timing diagram 600 can include a plurality of fingerprint frame periods FPR. The fingerprint frame period FPR can include a frame period F601, a frame period F602, and a frame period F603. In this embodiment, a reset period P_RST can be arranged in the frame period F601. In the reset period P_RST, the voltage signal Vsig can be held at the first voltage. The voltage VP of the fingerprint sensor 510 of each row can be sequentially reset row by row. In other words, the fingerprint sensor 510 can be reset row by row in the reset period P_RST.

[0092] In this embodiment, the initialization period P_INIT can be arranged in the frame period F602. In the fingerprint sensing cycle, the voltage signal Vsig can be kept at the initial voltage. The voltage signal VM1 of the gate of the reset switch M1 of each row can be switched from low to high for initialization of the fingerprint sensor 510. In addition, the voltage signal VM1 of the gate of the reset switch M1 of each row can be switched from high to low for exposure of the fingerprint sensor 510.

[0093] In this embodiment, the readout period P_READ can be arranged in the frame period F603. The voltage signal of the gate of the selection switch M3 of each row can be switched from low to high for readout of the fingerprint sensor 510.

[0094] In this way, the reset period P_RST can be arranged in one period before the fingerprint sensing cycle to reset the voltage VP of the reset node P of the fingerprint sensor 510 row by row, and thus the fingerprint image quality becomes more stable. The false rejection rate (FRR) and / or the false acceptance rate (FAR) of the fingerprint recognition can be reduced and the accuracy of the fingerprint recognition can be improved.

[0095] Figure 7 is a schematic timing diagram of a fingerprint sensor array according to one embodiment of the present disclosure. Reference is made to Figures 3 to 7 In the timing diagram 700, instead of arranging the reset period P_RST in a single frame period F601 separately, the reset period P_RST can belong to the same frame period F701 as the initialization period P_INIT. Specifically, the reset period P_RST can be arranged at the beginning of the frame period F701, and the initialization period P_INIT can be arranged after the reset period in the frame period F701. In the reset period P_RST, the voltage signal Vsig can be kept at the first voltage. The voltage VP of the fingerprint sensor 510 of each row can be reset simultaneously. In other words, the fingerprint sensor 510 can be reset simultaneously in the reset period P_RST. That is, all the gates of the fingerprint sensor 510 can be turned on simultaneously in the reset period P_RST. The initialization period P_INIT and the readout period P_READ can refer to the description of Figure 6 and will not be repeated herein.

[0096] In this way, the reset period P_RST can be arranged in one period before the fingerprint sensing cycle to reset the voltage VP of the reset node P of the fingerprint sensor 510 simultaneously, and thus the fingerprint image quality becomes more stable. The false rejection rate (FRR) and / or the false acceptance rate (FAR) of the fingerprint recognition can be reduced and the accuracy of the fingerprint recognition can be improved.

[0097] Figure 8is a schematic diagram of a touch display panel including a fingerprint sensor array according to one embodiment of the present disclosure. Referring to Figure 5 and Figure 8 A touch display panel 800 can be formed by integrating the fingerprint sensor array 500 with a plurality of pixels 820. That is, the touch display panel 800 can include a plurality of fingerprint sensors 810. The fingerprint sensors 810 can be described with reference to the description of the fingerprint sensor 510 shown in Figure 5 and will not be described herein again.

[0098] In this embodiment, each of the pixels 820 can include a pixel switch M4, a second capacitor C2, and a third capacitor C3. The pixel switch M4 can include a first terminal, a second terminal, and a control terminal. The second capacitor C2 can include a first terminal and a second terminal. The third capacitor C3 can include a first terminal and a second terminal. The second terminal of the pixel switch M4 can be electrically coupled to the first terminal of the second capacitor C2 and the first terminal of the third capacitor C3.

[0099] The touch display panel 800 can also include a plurality of display scan lines GD1 to GDn and a plurality of display data lines SD1 to SDn. The display scan lines GD1 to GDn can be configured to provide a gate drive voltage to the gate (i.e., the control terminal) of the pixel switch M4 of each pixel 820. The display data lines SD1 to SDn can be configured to provide a data voltage to the first terminal of the pixel switch M4 of each pixel 820. In one embodiment, the display data lines SD1 to SDn can be coupled to the touch display readout circuitry through a plurality of output terminals TP1 to TPn, although the present disclosure is not limited thereto. In this way, the touch display panel 800 integrates the plurality of fingerprint sensors 810 with the plurality of pixels.

[0100] It should be noted that the touch display panel 800 can be configured to operate in a fingerprint sensing mode and a touch display mode. In the fingerprint sensing mode, the touch display panel 800 can be configured to operate as a fingerprint sensor array. In the touch display mode, the touch display panel 800 can be configured to operate as a touch display panel. Figure 1 , Figure 2 and Figure 8The plurality of fingerprint sensors 810 arranged in an array can be located in the touch display panel 800. The touch display panel 800 can include a gate on array (GOA) circuit for fingerprint sensing control. The fingerprint readout circuit 120 can output at least one start pulse signal STV and a clock signal CLK to the gate on array circuit for fingerprint sensing control. For example, if the fingerprint sensor array is divided into four fingerprint sensing zones FZ1-FZ4 along a vertical direction (i.e., a fingerprint scanning direction), the fingerprint readout circuit 120 can provide start pulse signals STV1-STV4. Further, the GOA circuit for fingerprint sensing control can include four corresponding shift register circuits, where each shift register circuit can generate a reset signal RST based on one of the start pulse signals STV1-STV4 and the clock signal CLK, which is provided to the plurality of reset lines GSl-GSn connected to one of the fingerprint sensing zones FZ1-FZ4, respectively. In other words, the gate on array circuit can output the reset signal RST according to the at least one start pulse signal STV and the clock signal CLK. The reset signal RST can be configured to reset at least one fingerprint sensing zone of the fingerprint sensors 810 arranged in an array row by row in a reset period P_RST. For example, the sensor rows of the fingerprint sensing zone FZ1 can be reset row by row by the reset signal RST generated based on the start pulse signal STV1 and the clock signal CLK transmitted to the fingerprint sensing zone FZ1. The sensor rows of the fingerprint sensing zone FZ2 can be reset row by row by the reset signal RST generated based on the start pulse signal STV2 and the clock signal CLK transmitted to the fingerprint sensing zone FZ2. The sensor rows of the fingerprint sensing zone FZ3 can be reset row by row by the reset signal RST generated based on the start pulse signal STV3 and the clock signal CLK transmitted to the fingerprint sensing zone FZ3. The sensor rows of the fingerprint sensing zone FZ4 can be reset row by row by the reset signal RST generated based on the start pulse signal STV4 and the clock signal CLK transmitted to the fingerprint sensing zone FZ4. That is, the voltage VP of the reset node P of the fingerprint sensor 810 can be reset row by row according to the start pulse signal STV and the clock signal CLK output from the fingerprint readout circuit 120. It should be noted that both the initial signal for initializing the sensor rows of each fingerprint sensing zone and the reset signal RST are output to the reset lines GSl-GSn.

[0101] In one embodiment, the fingerprint readout circuit 120 can output at least one start pulse signal STV, a clock signal CLK, and a control signal SIM to the gate-on-array circuit for fingerprint sensing control. For example, if the fingerprint sensor array is divided into four fingerprint sensing zones FZ1-FZ4 along the vertical direction (i.e., the fingerprint scanning direction), the fingerprint readout circuit 120 can provide start pulse signals STV1-STV4 and a control signal SIM. Further, the GOA circuit for fingerprint sensing control can include four corresponding shift register circuits, where each shift register circuit can generate a reset signal RST based on one of the start pulse signals STV1-STV4 and the clock signal CLK, which is provided to the plurality of reset lines GSI-GSn connected to the fingerprint sensing zones FZ1-FZ4, respectively. Further, the shift register circuits can be configured to provide a reset signal RST to one or more of the fingerprint sensing zones FZ1-FZ4, which can reset all sensor rows of the one or more fingerprint sensing zones FZ1-FZ4 simultaneously, the reset signal RST being generated according to the control signal SIM. In other words, the gate-on-array circuit for fingerprint sensing control can output a reset signal RST according to the at least one start pulse signal STV, the clock signal CLK, and the control signal SIM. The reset signal RST can be configured to reset at least one fingerprint sensing zone of the fingerprint sensors 810 arranged in an array simultaneously in a reset period P_RST. For example, the reset signal RST can be configured to reset the sensor rows of the fingerprint sensing zones FZ1-FZ4 simultaneously based on the start pulse signals STV1-STV4, the clock signal CLK, and the control signal SIM. That is, the voltage VP of the reset node P of the fingerprint sensor 810 can be reset simultaneously according to the start pulse signal STV, the clock signal CLK, and the control signal SIM of the fingerprint readout circuit 120.

[0102] In one embodiment, the fingerprint readout circuit 120 can output at least one start pulse signal STV and a clock signal CLK to the on-array gate circuit for fingerprint sensing control. For example, if the fingerprint sensor array is divided into four fingerprint sensing zones FZ1 to FZ4 along the vertical direction (i.e., the fingerprint scanning direction), the fingerprint readout circuit 120 can provide start pulse signals STV1 to STV4. In addition, the GOA circuit for fingerprint sensing control can include four corresponding shift register circuits, where each shift register circuit can generate a selection signal SEL based on one of the start pulse signals STV1 to STV4 and the clock signal CLK, which is provided to the plurality of fingerprint scan lines SF1 to SFn connected to one of the fingerprint sensing zones FZ1 to FZ4, respectively. In other words, the on-array gate circuit for fingerprint sensing control can output selection signals SEL according to the at least one start pulse signal STV and the clock signal CLK. The selection signals SEL can be configured to read out the sensing voltages (outputs of the fingerprint sensor 200) of at least one fingerprint sensing zone of the fingerprint sensors 810 arranged in an array row by row in a readout period P_READ. For example, the sensing voltages of the sensor rows of the fingerprint sensing zone FZ1 can be read out row by row by the selection signals SEL generated based on the start pulse signal STV1 and the clock signal CLK to the fingerprint sensing zone FZ1. The sensing voltages of the sensor rows of the fingerprint sensing zone FZ2 can be read out row by row by the selection signals SEL generated based on the start pulse signal STV2 and the clock signal CLK to the fingerprint sensing zone FZ2. The sensing voltages of the sensor rows of the fingerprint sensing zone FZ3 can be read out row by row by the selection signals SEL generated based on the start pulse signal STV3 and the clock signal CLK to the fingerprint sensing zone FZ3. The sensing voltages of the sensor rows of the fingerprint sensing zone FZ4 can be read out row by row by the selection signals SEL generated based on the start pulse signal STV4 and the clock signal CLK to the fingerprint sensing zone FZ4. That is, the sensing voltages of the sensor rows of the fingerprint sensors 810 can be read out row by row according to the start pulse signals STV and the clock signal CLK of the fingerprint readout circuit 120.

[0103] Figure 9 is a schematic timing diagram of a touch display panel including a fingerprint sensor array according to a first embodiment of the present disclosure. Referring to Figures 6 to 9The timing diagram 900 can include a plurality of frame periods F901 to F907. In addition, the timing diagram 900 can include a plurality of fingerprint frame periods denoted by FPR and a plurality of touch display frame periods denoted by DP+TP. Furthermore, in the timing diagram 900, a mode signal Sync can represent a mode of the touch display panel 800. When the mode signal Sync is at a high level, the fingerprint sensing function of the touch display panel 800 can be enabled and the display function and the touch sensing function of the touch display panel 800 can be disabled. When the mode signal Sync is at a low level, the fingerprint sensing function of the touch display panel 800 can be disabled and the display function and the touch sensing function of the touch display panel 800 can be enabled.

[0104] In this embodiment, the frame period F901, the frame period F903, the frame period F905, and F907 can be touch display frame periods DP+TP, and the frame period F902, the frame period F904, and the frame period F906 can be fingerprint frame periods FPR. In the fingerprint frame periods FPR, the reset period P_RST can belong to the frame period F902, the initialization period P_INIT can belong to the frame period F904, and the readout period P_READ can belong to the frame period F906. That is, one frame between two successive touch display frame periods DP+TP can be arranged for a fingerprint frame period FPR. In other words, the touch display frame periods DP+TP and the fingerprint frame periods FPR can be arranged alternately in the timing diagram 900. The operation mode of the touch display panel 800 with such an arrangement can be referred to as a "frame skip mode".

[0105] It should be noted that one cycle of a fingerprint sensing cycle can be defined from the initialization period P_INIT to the readout period P_READ. The initialization period P_INIT of the fingerprint sensing cycle can be in a first frame period. The readout period P_READ of the fingerprint sensing cycle can be in a second frame period different from the first frame period. That is, one fingerprint sensing cycle can be defined from the frame period F904 to the frame period F906. In this embodiment, one touch display frame period DP+TP (the frame period F905) is arranged between the frame period F904 to which the initialization period P_INIT of the same fingerprint cycle belongs and the frame period F906 to which the readout period P_READ belongs. However, the number of touch display frame periods between the fingerprint sensing frame period to which the initialization period P_INIT of the same fingerprint cycle belongs and the other fingerprint sensing frame period to which the readout period P_READ belongs is not limited to this. In other words, the length of time between the initialization period P_INIT and the readout period P_READ can include one or more frame periods. In the one or more frame periods between the initialization period P_INIT and the readout period P_READ, at least one of the display function and the touch sensing function is enabled and the fingerprint sensing function is disabled.

[0106] In this embodiment, the reset period P_RST can be arranged in the frame period F902. The voltage VP of the reset node P of each of the fingerprint sensors 810 of the touch display panel 800 can be reset row by row in the reset period P_RST. In this embodiment, after the frame period F902 in which the reset period P_RST is arranged, there is one fingerprint sensing cycle arranged from the frame period F904 to the frame period F906, but the number of fingerprint sensing cycles arranged after the reset period P_RST is not limited to this.

[0107] In addition, in this embodiment, one touch display frame period DP+TP (the frame period F903) is arranged between the reset period P_RST (the frame period F902) and the initialization period P_INIT (the frame period F904). However, the number of touch display frame periods DP+TP between the fingerprint sensing frame period to which the reset period P_RST belongs and another fingerprint sensing frame period to which the initialization period P_INIT belongs in the same cycle is not limited to this. That is, the length of time between the reset period P_RST and the fingerprint sensing cycle can include one or more frame periods. In the one or more frame periods between the reset period P_RST and the fingerprint sensing cycle, at least one of a display function and a touch sensing function is enabled and a fingerprint sensing function is disabled. In addition, the fingerprint sensors 810 are reset row by row in the reset period P_RST.

[0108] Figure 10 is a schematic timing diagram of a touch display panel including a fingerprint sensor array according to a second embodiment of the present disclosure. Referring to Figures 8 to 10 , the timing diagram 1000 can include a plurality of frame periods F1001 to F1011.

[0109] In this embodiment, the frame periods F1001, F1003, F1005, F1007, F1009, and F1011 can be touch display frame periods DP+TP, and the frame periods F1002, F1004, F1006, F1008, and F1010 can be fingerprint frame periods FPR.

[0110] In the fingerprint frame period FPR, the reset period P_RST can belong to the frame period F1002. The initialization period P_INIT of the first fingerprint sensing cycle Cycle1 can belong to the frame period F1004, and the readout period P_READ of the first fingerprint sensing cycle Cycle1 can belong to the frame period F1006. The initialization period P_INIT of the second fingerprint sensing cycle Cycle2 can belong to the frame period F1006, and the readout period P_READ of the second fingerprint sensing cycle Cycle2 can belong to the frame period F1008. The initialization period P_INIT of the Nth fingerprint sensing cycle CycleN can belong to the frame period F1008, and the readout period P_READ of the Nth fingerprint sensing cycle CycleN can belong to the frame period F1010.

[0111] That is, one reset period P_RST can be arranged before N fingerprint sensing cycles. In other words, the voltage VP of the reset node P of each fingerprint sensor 810 of the touch display panel 800 can be reset row by row in the reset period P_RST before the N fingerprint sensing cycles, and thus, the quality of the fingerprint image becomes more stable. Therefore, the false rejection rate (FRR) and / or the false acceptance rate (FAR) of the fingerprint recognition can be reduced and the accuracy of the fingerprint recognition can be improved.

[0112] In addition, the readout period P_READ of the first fingerprint sensing cycle Cycle1 and the initialization period P_INIT of the second fingerprint sensing cycle Cycle2 can belong to the same frame period F1006. The readout period P_READ of the second fingerprint sensing cycle Cycle2 and the initialization period P_INIT of the Nth fingerprint sensing cycle CycleN can belong to the same frame period F1008. That is, the readout period P_READ of one cycle and the initialization period P_INIT of the next fingerprint sensing cycle can belong to the same frame period. Therefore, the frame periods required by the N fingerprint sensing cycles can be reduced.

[0113] Figure 11 is a schematic timing diagram of a touch display panel including a fingerprint sensor array according to a third embodiment of the present disclosure. Referring to Figures 8 to 11 , the timing diagram 1100 can include a plurality of frame periods F1101 to F1113.

[0114] In this embodiment, the frame periods F1101, F1103, F1105, F1107, F1109, F1111, and F1113 can be touch display frame periods DP+TP, and the frame periods F1102, F1104, F1106, F1108, F1110, and F1112 can be fingerprint frame periods FPR.

[0115] In the fingerprint frame period FPR, the reset period P_RST of the first fingerprint sensing cycle Cycle1 can belong to the frame period F1102, and the reset period P_RST of the Nth fingerprint sensing cycle CycleN can belong to the frame period F1108. The initialization period P_INIT of the first fingerprint sensing cycle Cycle1 can belong to the frame period F1104, and the readout period P_READ of the first fingerprint sensing cycle Cycle1 can belong to the frame period F1106. The initialization period P_INIT of the Nth fingerprint sensing cycle CycleN can belong to the frame period F1110, and the readout period P_READ of the Nth fingerprint sensing cycle CycleN can belong to the frame period F1112.

[0116] That is, a reset period P_RST can be arranged before each fingerprint sensing cycle. In other words, the voltage VP of the reset node P of each fingerprint sensor 810 of the touch display panel 800 can be reset row by row in the reset period P_RST before each fingerprint sensing cycle, and thus the fingerprint image quality becomes more stable. Therefore, the false rejection rate (FRR) and / or the false acceptance rate (FAR) of the fingerprint recognition can be reduced and the accuracy of the fingerprint recognition can be improved.

[0117] Figure 12 is a schematic timing diagram of a touch display panel including a fingerprint sensor array according to a fourth embodiment of the present disclosure. Referring to Figures 8 to 12 , the timing diagram 1200 can include a plurality of frame periods F1201 to F1208.

[0118] In this embodiment, the frame periods F1201, F1203, F1205, F1206, and F1207 can be touch display frame periods DP+TP, and the frame periods F1202, F1204, and F1208 can be fingerprint frame periods FPR. In the fingerprint frame period FPR, the reset period P_RST can belong to the frame period F1202, the initialization period P_INIT can belong to the frame period F1204, and the readout period P_READ can belong to the frame period F1208.

[0119] In this embodiment, the touch display frame periods DP+TP (frame periods F1205 to F1207) can be arranged between two successive fingerprint frame periods FPR (frame period F1204 and frame period F1208) of the same fingerprint sensing cycle. That is, a plurality of touch display frame periods DP+TP can be arranged between the initialization period P_INIT and the readout period P_READ of the same fingerprint sensing cycle. In other words, the length of time between the initialization period P_INIT and the readout period P_READ can include one or more frame periods. In the one or more frame periods between the initialization period P_INIT and the readout period P_READ, at least one of the display function and the touch sensing function is enabled and the fingerprint sensing function is disabled.

[0120] Figure 13 is a schematic timing diagram of a touch display panel including a fingerprint sensor array according to a fifth embodiment of the present disclosure. Referring to Figures 8 to 13 , the timing diagram 1300 can include a plurality of frame periods F1301 to F1305.

[0121] In this embodiment, the frame periods F1301, F1303, and F1305 can be touch display frame periods DP+TP, and the frame periods F1302 and F1304 can be fingerprint frame periods FPR. In the fingerprint frame periods FPR, the reset period P_RST and the initialization period P_INIT of the fingerprint sensing cycle can belong to the same frame period F1302. Furthermore, the fingerprint sensors 810 can be reset at the same time, instead of being reset row by row. Therefore, the time for resetting all of the fingerprint sensors 810 of the touch display panel 800 can be reduced.

[0122] In this embodiment, one touch display frame period DP+TP (frame period F1303) is arranged between the reset period P_RST (frame period F1302) and the initialization period P_INIT (frame period F1304) of the same fingerprint sensing cycle. However, the number of touch display frame periods DP+TP between the reset period P_RST and the initialization period P_INIT of the same fingerprint sensing cycle is not limited thereto.

[0123] Figure 14 is a schematic timing diagram of a touch display panel including a fingerprint sensor array according to a sixth embodiment of the present disclosure. Referring to Figures 8 to 14 , the timing diagram 1400 can include a plurality of frame periods F1401 to F1407.

[0124] In this embodiment, the frame periods F1401, F1403, F1404, F1405, and F1407 can be touch display frame periods DP+TP, and the frame periods F1402 and F1406 can be fingerprint frame periods FPR. In the fingerprint frame periods FPR, the reset period P_RST and the initialization period P_INIT of the fingerprint sensing cycle can belong to the same frame period F1402. Furthermore, the fingerprint sensor 810 can be reset at the same time, instead of being reset row by row. Therefore, the time for resetting all the fingerprint sensors 810 of the touch display panel 800 can be reduced.

[0125] In this embodiment, the touch display frame periods DP+TP (frame periods F1403 to F1405) can be arranged between two successive fingerprint frame periods FPR (frame period F1402 and frame period F1406) of the same fingerprint sensing cycle. That is, a plurality of touch display frame periods DP+TP can be arranged between the initialization period P_INIT and the readout period P_READ of the same fingerprint sensing cycle. In other words, the length of time between the initialization period P_INIT and the readout period P_READ can include one or more frame periods. In the one or more frame periods between the initialization period P_INIT and the readout period P_READ, at least one of the display function and the touch sensing function is enabled and the fingerprint sensing function is disabled.

[0126] Unlike the aforementioned skip frame mode, a “porch mode” is also an operation mode for fingerprint sensing of the touch display panel 800. In the porch mode, the fingerprint sensing operations (e.g., initialization, readout, and reset before the fingerprint sensing cycle) are performed in a porch interval. It should be noted that the porch interval can be defined as the length of time between the end of outputting a display frame of the touch display panel 800 and the start of outputting the next display frame of the touch display panel 800. That is, the entire porch interval can be between two adjacent frames. A portion of the porch interval is in the current frame period, and another portion of the porch interval is in the next frame period. The length of the porch interval can be predetermined based on the display refresh rate of the touch display panel 800. When the display refresh rate is variable (which is referred to as variable refresh rate (VRR)), the length of the porch interval can also be variable.

[0127] In one embodiment, the reset period P_RST and the fingerprint sensing cycle can be performed in a porch interval. The porch interval can be located in two adjacent frame periods. That is, the reset period P_RST and the fingerprint sensing cycle can be arranged in the porch interval between two successive touch display frame periods DP+TP.

[0128] In the edge interval, the plurality of fingerprint sensors 810 can be reset row by row in a reset period P_RST. In another embodiment, all rows of the plurality of fingerprint sensors 810 can be reset simultaneously in the reset period P_RST, and the present disclosure is not limited thereto.

[0129] In one embodiment, the reset period P_RST can be in a first edge interval. The fingerprint sensing cycle can be performed completely by a plurality of second edge intervals after the first edge interval. Furthermore, any one of the first edge interval and the second edge intervals can be located in two adjacent frame periods. That is, the reset period P_RST and the fingerprint sensing cycle can be arranged in different edge intervals. The initialization period P_INIT, the exposure period P_EXP, and the readout period P_READ of the same fingerprint sensing cycle can be arranged in different edge intervals.

[0130] Figure 15 is a schematic diagram of a fingerprint readout circuit according to one embodiment of the present disclosure. Referring to Figure 2 , Figure 8 and Figure 15 , the fingerprint readout circuit 1500 can be configured to be coupled to a touch display panel 1510. The touch display panel can include a plurality of fingerprint sensors 1521 arranged in a sensor array 1520 and an on-array gate circuit 1530 for fingerprint sensing control. The fingerprint readout circuit 1500 can be coupled to the plurality of fingerprint sensors 1521 via a plurality of sensing lines 1540. The fingerprint readout circuit 1500 can be coupled to the on-array gate circuit 1530. The fingerprint readout circuit 1500 can be configured to output at least one start pulse signal STV and at least one clock signal CLK to control the on-array gate circuit 1530 to output a reset signal RST and a selection signal SEL. The reset signal RST and the selection signal SEL can be configured to control at least one fingerprint sensing region of the fingerprint sensors 1521 arranged in the sensor array 1520 to operate in a fingerprint sensing cycle. The fingerprint sensing cycle can include an initialization period P_INIT, an exposure period P_EXP, and a readout period P_READ. According to the reset signal RST, a voltage VP of a reset node P in each of the fingerprint sensors 1521 can be reset to a first voltage in a reset period P_RST before the fingerprint sensing cycle starts. The voltage VP of the reset node P in each of the fingerprint sensors 1521 can be initialized to an initial voltage in the initialization period P_INIT. The initial voltage is different from the first voltage.

[0131] In one embodiment, the fingerprint readout circuit 1500 can be configured to output a voltage signal Vsig to the touch display panel 1510. The voltage signal Vsig can be held at a first voltage in a reset period P_RST. The voltage signal Vsig can be held at an initial voltage in an initialization period P_INIT. The first voltage is different from the initial voltage. For example, the first voltage is 0 V, and the initial voltage is an operating voltage (e.g., 4 V).

[0132] In one embodiment, the reset node P can be electrically coupled to a power supply node that is supplied with the voltage signal Vsig.

[0133] In one embodiment, the fingerprint readout circuit 1500 can output at least one start pulse signal STV and a clock signal CLK to the on-array gate circuit 1530. The on-array gate circuit 1530 can output a reset signal RST according to the at least one start pulse signal STV and the clock signal CLK. The reset signal RST can be configured to reset at least one fingerprint sensing zone of the fingerprint sensors 1521 arranged into the sensor array 1520 row by row in a reset period P_RST.

[0134] In one embodiment, the fingerprint readout circuit 1500 can output at least one start pulse signal STV, a clock signal CLK, and a control signal SIM to the on-array gate circuit 1530. For example, if the fingerprint sensor array is divided into four fingerprint sensing zones FZ1-FZ4 along a vertical direction (i.e., a fingerprint scanning direction), the fingerprint readout circuit 120 can provide start pulse signals STV1-STV4 and the control signal SIM. Further, the on-array gate circuit 1530 can include four corresponding shift register circuits, where each shift register circuit can generate a reset signal RST based on one of the start pulse signals STV1-STV4 and the clock signal CLK, which is provided to a plurality of reset lines GSl-GSn connected to the fingerprint sensing zones FZ1-FZ4, respectively. Further, the shift register circuits can be configured to provide the reset signal RST to the fingerprint sensing zones FZ1-FZ4 simultaneously according to the control signal SIM. In other words, the on-array gate circuit 1530 can output a reset signal RST according to the at least one start pulse signal STV, the clock signal CLK, and the control signal SIM. The reset signal RST can be configured to reset at least one fingerprint sensing zone of the fingerprint sensors 1521 arranged into the sensor array 1520 simultaneously in a reset period P_RST.

[0135] In one embodiment, the fingerprint readout circuit 1500 can output at least one start pulse signal STV and a clock signal CLK to the on-array gate circuit 1530. The on-array gate circuit 1530 can output a selection signal SEL according to the at least one start pulse signal STV and the clock signal CLK. The selection signal SEL can be configured to read out a sensing voltage of at least one fingerprint sensing area of the fingerprint sensor 1521 arranged into the sensor array 1520 row by row in a readout period P READ.

[0136] In this way, the reset period P_RST can be arranged before the fingerprint sensing cycle to reset the voltage VP of the reset node P of the fingerprint sensor 1521, and thus the fingerprint image quality becomes more stable. The false rejection rate (FRR) and / or the false acceptance rate (FAR) of the fingerprint recognition can be reduced and the accuracy of the fingerprint recognition can be improved.

[0137] Figure 16 is a schematic diagram of a touch display panel according to one embodiment of the disclosure. Referring to Figure 2 , Figure 8 and Figure 16 , the touch display panel 1600 can include a plurality of sensing lines 1620, a plurality of fingerprint sensors 1610. The plurality of fingerprint sensors 1610 can be configured to operate in a fingerprint sensing cycle. The plurality of fingerprint sensors 1610 can be coupled to a fingerprint readout circuit 1630 via the sensing lines 1620. The fingerprint sensing cycle includes an initialization period P INIT, an exposure period P EXP, and a readout period P READ. The voltage VP of a reset node P in each of the plurality of fingerprint sensors 1610 can be reset to a first voltage in a reset period P_RST before the start of the fingerprint sensing cycle. The voltage VP of the reset node P in each of the plurality of fingerprint sensors 1610 can be initialized to an initial voltage in the initialization period P INIT. The initial voltage is different from the first voltage.

[0138] In one embodiment, the sensing voltage (output of the fingerprint sensor 200) of each of the plurality of fingerprint sensors 1610 can be read out by the fingerprint readout circuit 1630 via the corresponding sensing line 1620. The sensing voltage of each of the plurality of fingerprint sensors 1610 follows the voltage VP of the reset node P. The sensing result of each of the plurality of fingerprint sensors 1610 can be generated by the fingerprint readout circuit 1630 based on a voltage change between the initial voltage and the sensing voltage for the fingerprint sensing cycle.

[0139] In one embodiment, referring to Figure 15 and Figure 16The touch display panel 1600 can further include an on-array gate circuit 1530 for fingerprint sensing control. The on-array gate circuit 1530 can receive at least one start pulse signal STV and a clock signal CLK from the fingerprint readout circuit 1630. The on-array gate circuit 1530 can output a reset signal RST according to the at least one start pulse signal STV and the clock signal CLK. The reset signal RST can be configured to reset at least one fingerprint sensing area of the fingerprint sensors 1610 arranged into the sensor array 1520 row by row in a reset period P_RST.

[0140] In one embodiment, referring to Figure 15 and Figure 16 The touch display panel 1600 can further include an on-array gate circuit 1530 for fingerprint sensing control. The on-array gate circuit 1530 can receive at least one start pulse signal STV, a clock signal CLK, and a control signal SIM from the fingerprint readout circuit 1630. The on-array gate circuit 1530 can output a reset signal RST according to the at least one start pulse signal STV, the clock signal CLK, and the control signal SIM. The reset signal RST is configured to reset at least one fingerprint sensing area of the fingerprint sensors 1610 arranged into the sensor array 1520 simultaneously in a reset period P_RST.

[0141] In one embodiment, referring to Figure 15 and Figure 16 The touch display panel 1600 can further include an on-array gate circuit 1530 for fingerprint sensing control. The on-array gate circuit 1530 can receive at least one start pulse signal STV and a clock signal CLK from the fingerprint readout circuit 1630. The on-array gate circuit 1530 can output a selection signal SEL according to the at least one start pulse signal STV and the clock signal CLK. The selection signal SEL can be configured to read out a sensing voltage of at least one fingerprint sensing area of the fingerprint sensors 1610 arranged into the sensor array 1520 row by row in a readout period P_READ.

[0142] In this way, the reset period P_RST can be arranged before the fingerprint sensing cycle to reset the voltage VP of the reset node P of the fingerprint sensors 1610, and thus the quality of the fingerprint image becomes more stable. The false rejection rate (FRR) and / or the false acceptance rate (FAR) of the fingerprint recognition can be reduced and the accuracy of the fingerprint recognition can be improved.

[0143] In summary, according to the fingerprint sensing device, the fingerprint readout circuit and the touch display panel of the present disclosure, the reset period is arranged before the fingerprint sensing cycle to reset the voltage of the reset node of the fingerprint sensor. Therefore, the fingerprint image quality becomes more stable, and the false rejection rate (FRR) and / or the false acceptance rate (FAR) of the fingerprint recognition is reduced and the accuracy of the fingerprint recognition is improved.

[0144] Various modifications and changes can be made to the disclosed embodiments without departing from the scope or spirit of the disclosure. It is intended that the disclosure cover such modifications and changes.

Claims

1. A fingerprint sensing device, comprising: a plurality of fingerprint sensors configured to operate in a fingerprint sensing cycle; as well as a fingerprint reading circuit coupled to the plurality of fingerprint sensors via a plurality of sensing lines and configured to control the plurality of fingerprint sensors to operate in the fingerprint sensing cycle, The fingerprint sensing cycle includes an initialization period, an exposure period and a readout period. The voltage of the reset node in each of the plurality of fingerprint sensors is reset to a first voltage in a reset period before the fingerprint sensing cycle starts. The voltage of the reset node in each fingerprint sensor is initialized to an initial voltage during the initialization period, and The initial voltage is different from the first voltage, wherein the reset node is electrically coupled to a power supply node supplied with a voltage signal, and in the fingerprint sensing cycle, the voltage signal remains at the initial voltage.

2. The fingerprint sensing device according to claim 1, wherein The fingerprint reading circuit reads out a sensing voltage of each fingerprint sensor via a corresponding sensing line among the plurality of sensing lines during the reading period. wherein the sense voltage follows the voltage of the reset node, and The fingerprint reading circuit generates a sensing result of each fingerprint sensor based on a voltage change between the initial voltage and the sensing voltage.

3. The fingerprint sensing device according to claim 1, wherein The voltage signal remains at the first voltage during the reset period, and The voltage signal is maintained at the initial voltage during the initialization period. 4 . The fingerprint sensing device according to claim 3 , wherein the fingerprint reading circuit is configured to output the voltage signal to a touch display panel.

5. The fingerprint sensing device according to claim 1, wherein The initialization period of the fingerprint sensing cycle is in the first frame period, The readout period of the fingerprint sensing cycle is in a second frame period different from the first frame period, and The time length between the initialization period and the readout period includes one or more frame periods, In the one or more frame periods between the initialization period and the readout period, at least one of a display function and a touch sensing function is enabled and a fingerprint sensing function is disabled.

6. The fingerprint sensing device according to claim 1, wherein The time length between the reset period and the fingerprint sensing cycle includes one or more frame periods. wherein in the one or more frame periods between the reset period and the fingerprint sensing cycle, at least one of a display function and a touch sensing function is enabled and a fingerprint sensing function is disabled, and The plurality of fingerprint sensors are reset row by row during the reset period.

7. The fingerprint sensing device according to claim 1, wherein The reset period and the initialization period of the fingerprint sensing cycle belong to the same frame period, and The multiple fingerprint sensors are reset simultaneously.

8. The fingerprint sensing device according to claim 1, wherein The reset period and the fingerprint sensing cycle are performed at edge intervals, and The edge interval is located in two adjacent frame periods. 9 . The fingerprint sensing device according to claim 8 , wherein the plurality of fingerprint sensors are reset row by row in the reset period. 10 . The fingerprint sensing device according to claim 8 , wherein the plurality of fingerprint sensors are reset simultaneously.

11. The fingerprint sensing device according to claim 1, wherein The reset period is in the first edge interval, and The fingerprint sensing cycle is completely executed by a plurality of second edge intervals following the first edge interval, The first edge interval and any one of the plurality of second edge intervals are located in two adjacent frame periods.

12. The fingerprint sensing device according to claim 1, wherein The plurality of fingerprint sensors arranged in an array are located in the touch display panel, and The touch display panel includes an array upper gate circuit, The fingerprint reading circuit outputs at least one starting pulse signal and a clock signal to the array gate circuit, and The array upper gate circuit outputs a reset signal according to the at least one start pulse signal and the clock signal, The reset signal is configured to reset at least one fingerprint sensing area of ​​the plurality of fingerprint sensors arranged in the array row by row during the reset period.

13. The fingerprint sensing device according to claim 1, wherein The plurality of fingerprint sensors arranged in an array are located in the touch display panel, and The touch display panel includes an array upper gate circuit, The fingerprint reading circuit outputs at least one starting pulse signal, a clock signal and a control signal to the array gate circuit, and The array upper gate circuit outputs a reset signal according to the at least one start pulse signal, the clock signal and the control signal, The reset signal is configured to simultaneously reset at least one fingerprint sensing area of ​​the plurality of fingerprint sensors arranged in the array during the reset period.

14. The fingerprint sensing device according to claim 1, wherein The plurality of fingerprint sensors arranged in an array are located in the touch display panel, and The touch display panel includes an array upper gate circuit, The fingerprint reading circuit outputs at least one starting pulse signal and a clock signal to the array gate circuit, and The array upper gate circuit outputs a selection signal according to the at least one start pulse signal and the clock signal, The selection signal is configured to read out the sensing voltage of at least one fingerprint sensing region of the plurality of fingerprint sensors arranged in the array row by row during the readout period.

15. A fingerprint reading circuit capable of being configured to be coupled to a touch display panel, wherein the touch display panel comprises a plurality of fingerprint sensors arranged in an array and an array gate circuit, and The fingerprint readout circuit is coupled to the plurality of fingerprint sensors via a plurality of sensing lines and is coupled to the array gate circuit; and The fingerprint reading circuit is configured to output at least one start pulse signal and at least one clock signal to control the array gate circuit to output a reset signal and a selection signal. wherein the reset signal and the selection signal are configured to control at least one fingerprint sensing area of ​​the plurality of fingerprint sensors arranged in the array to operate in a fingerprint sensing cycle, The fingerprint sensing cycle includes an initialization period, an exposure period, and a readout period, and wherein according to the reset signal, the voltage of the reset node in each of the plurality of fingerprint sensors is reset to a first voltage in a reset period before the fingerprint sensing cycle starts, The voltage of the reset node in each fingerprint sensor is initialized to an initial voltage during the initialization period, and The initial voltage is different from the first voltage, wherein the reset node is electrically coupled to a power supply node supplied with a voltage signal, and in the fingerprint sensing cycle, the voltage signal remains at the initial voltage.

16. The fingerprint reading circuit according to claim 15, wherein The fingerprint reading circuit reads out a sensing voltage of each fingerprint sensor via a corresponding sensing line among the plurality of sensing lines during the reading period. wherein the sense voltage follows the voltage of the reset node, and The fingerprint reading circuit generates a sensing result of each fingerprint sensor based on a voltage change between the initial voltage and the sensing voltage.

17. The fingerprint reading circuit according to claim 15, wherein The fingerprint reading circuit is configured to output a voltage signal to the touch display panel, wherein the voltage signal remains at the first voltage during the reset period, and The voltage signal is maintained at the initial voltage during the initialization period.

18. The fingerprint reading circuit according to claim 15, wherein The initialization period of the fingerprint sensing cycle is in the first frame period, The readout period of the fingerprint sensing cycle is in a second frame period different from the first frame period, and The time length between the initialization period and the readout period includes one or more frame periods, In the one or more frame periods between the initialization period and the readout period, at least one of a display function and a touch sensing function is enabled and a fingerprint sensing function is disabled.

19. The fingerprint reading circuit according to claim 15, wherein The time length between the reset period and the fingerprint sensing cycle includes one or more frame periods. wherein in the one or more frame periods between the reset period and the fingerprint sensing cycle, at least one of a display function and a touch sensing function is enabled and a fingerprint sensing function is disabled, and The plurality of fingerprint sensors are reset row by row during the reset period.

20. The fingerprint reading circuit according to claim 15, wherein The reset period and the initialization period of the fingerprint sensing cycle belong to the same frame period, and The multiple fingerprint sensors are reset simultaneously.

21. The fingerprint reading circuit according to claim 15, wherein The reset period and the fingerprint sensing cycle are performed at edge intervals, and The edge interval is located in two adjacent frame periods.

22. The fingerprint sensing circuit according to claim 21, wherein the plurality of fingerprint sensors are reset row by row in the reset period.

23. The fingerprint sensing circuit according to claim 21, wherein the plurality of fingerprint sensors are reset simultaneously.

24. The fingerprint reading circuit according to claim 15, wherein The reset period is in the first edge interval, and The fingerprint sensing cycle is completely executed by a plurality of second edge intervals following the first edge interval, The first edge interval and any one of the plurality of second edge intervals are located in two adjacent frame periods.

25. The fingerprint sensing circuit according to claim 15, wherein The fingerprint reading circuit outputs at least one start pulse signal and a clock signal to the array gate circuit, and The array upper gate circuit outputs a reset signal according to the at least one start pulse signal and the clock signal, The reset signal is configured to reset at least one fingerprint sensing area of ​​the plurality of fingerprint sensors arranged in the array row by row during the reset period.

26. The fingerprint reading circuit according to claim 15, wherein The fingerprint reading circuit outputs at least one start pulse signal, a clock signal and a control signal to the array gate circuit, and The array upper gate circuit outputs a reset signal according to the at least one start pulse signal, the clock signal and the control signal, The reset signal is configured to simultaneously reset at least one fingerprint sensing area of ​​the plurality of fingerprint sensors arranged in the array during the reset period.

27. The fingerprint reading circuit according to claim 15, wherein The fingerprint reading circuit outputs at least one start pulse signal and a clock signal to the array gate circuit, and The array upper gate circuit outputs a selection signal according to the at least one start pulse signal and the clock signal, The selection signal is configured to read out the sensing voltage of at least one fingerprint sensing region of the plurality of fingerprint sensors arranged in the array row by row during the readout period.

28. A touch display panel, comprising: Multiple sensing lines; as well as a plurality of fingerprint sensors configured to operate in a fingerprint sensing cycle and coupled to a fingerprint readout circuit via the plurality of sensing lines, The fingerprint sensing cycle includes an initialization period, an exposure period and a readout period. The voltage of the reset node in each of the plurality of fingerprint sensors is reset to a first voltage in a reset period before the fingerprint sensing cycle starts. The voltage of the reset node in each fingerprint sensor is initialized to an initial voltage during the initialization period, and The initial voltage is different from the first voltage, wherein the reset node is electrically coupled to a power supply node supplied with a voltage signal, and in the fingerprint sensing cycle, the voltage signal remains at the initial voltage.

29. The touch display panel according to claim 28, wherein The sensing voltage of each fingerprint sensor is read out by the fingerprint reading circuit via the corresponding sensing line among the plurality of sensing lines. wherein the sensing voltage of each fingerprint sensor follows the voltage of the reset node, and The fingerprint reading circuit generates a sensing result of each fingerprint sensor for the fingerprint sensing cycle based on a voltage change between the initial voltage and the sensing voltage.

30. The touch display panel according to claim 28, wherein The voltage signal remains at the first voltage during the reset period, and The voltage signal is maintained at the initial voltage during the initialization period. 31 . The touch display panel according to claim 30 , wherein the fingerprint sensing circuit is configured to output the voltage signal to the touch display panel.

32. The touch display panel according to claim 28, wherein The initialization period of the fingerprint sensing cycle is in the first frame period, The readout period of the fingerprint sensing cycle is in a second frame period different from the first frame period, and The time length between the initialization period and the readout period includes one or more frame periods, In the one or more frame periods between the initialization period and the readout period, at least one of a display function and a touch sensing function is enabled and a fingerprint sensing function is disabled.

33. The touch display panel according to claim 28, wherein The time length between the reset period and the fingerprint sensing cycle includes one or more frame periods. wherein in the one or more frame periods between the reset period and the fingerprint sensing cycle, at least one of a display function and a touch sensing function is enabled and a fingerprint sensing function is disabled, and The plurality of fingerprint sensors are reset row by row during the reset period.

34. The touch display panel according to claim 28, wherein The reset period and the initialization period of the fingerprint sensing cycle belong to the same frame period, and The multiple fingerprint sensors are reset simultaneously.

35. The touch display panel according to claim 28, wherein The reset period and the fingerprint sensing cycle are performed at edge intervals, and The edge interval is located in two adjacent frame periods. 36 . The touch display panel according to claim 35 , wherein the plurality of fingerprint sensors are reset row by row in the reset period. The touch display panel according to claim 35 , wherein the plurality of fingerprint sensors are reset simultaneously.

38. The touch display panel according to claim 28, wherein The reset period is in the first edge interval, and The fingerprint sensing cycle is completely executed by a plurality of second edge intervals following the first edge interval, The first edge interval and any one of the plurality of second edge intervals are located in two adjacent frame periods.

39. The touch display panel according to claim 28, further comprising an array upper gate circuit, wherein The array gate circuit receives at least one start pulse signal and a clock signal from the fingerprint reading circuit, and The array upper gate circuit outputs a reset signal according to the at least one start pulse signal and the clock signal, The reset signal is configured to reset at least one fingerprint sensing area of ​​the plurality of fingerprint sensors arranged in an array row by row during the reset period.

40. The touch display panel according to claim 28, further comprising an array upper gate circuit, wherein The array gate circuit receives at least one start pulse signal, a clock signal and a control signal from the fingerprint reading circuit, and The array upper gate circuit outputs a reset signal according to the at least one start pulse signal, the clock signal and the control signal, The reset signal is configured to simultaneously reset at least one fingerprint sensing area of ​​the plurality of fingerprint sensors arranged in an array during the reset period.

41. The touch display panel according to claim 28, further comprising an array upper gate circuit, wherein The array gate circuit receives at least one start pulse signal and a clock signal from the fingerprint reading circuit, and The array upper gate circuit outputs a selection signal according to the at least one start pulse signal and the clock signal, The selection signal is configured to read out the sensing voltage of at least one fingerprint sensing region of the plurality of fingerprint sensors arranged in an array row by row during the readout period.

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