Fingerprint driving circuit, fingerprint sensing device, electronic device and operation method

Abstract

The present invention provides a fingerprint driving circuit, a fingerprint sensing device, an electronic device, and an operating method, which can prevent the display panel from flickering by keeping the fingerprint sensing line in the non-fingerprint sensing area in an electrically non-floating state.

Description

Technical Field

[0001] This invention relates to an electronic device, and more particularly to a fingerprint driving circuit, a fingerprint sensing device, and a method of operating the fingerprint sensing device. Background Technology

[0002] In recent years, the demand for fingerprint sensing has been gradually increasing. To reduce the size of electronic devices, the fingerprint sensing area can overlap with the display area. For example, under-display fingerprint recognition technology embeds the fingerprint sensor in the display panel, allowing the sensor to sense or capture fingerprint images through the display panel. When a touch event occurs (i.e., a finger touches the display panel), the touch sensing circuit reports back to the application processor of the electronic device. The application processor then further controls the display driving circuit to drive the display panel to display the image used for fingerprint sensing. Conversely, the application processor further controls the fingerprint sensing circuit to perform the fingerprint sensing operation. Summary of the Invention

[0003] The present invention provides a fingerprint driving circuit, a fingerprint sensing device, an electronic device, and a method for operating the fingerprint sensing device, so as to avoid display abnormalities in non-fingerprint sensing areas as much as possible.

[0004] In an embodiment of the present invention, the fingerprint driving circuit includes a first switch, a second switch, a current source, an analog front-end circuit, and a current or voltage source. A first terminal of the first switch is coupled to a corresponding fingerprint sensing line among multiple fingerprint sensing lines on the display panel. The current source is coupled to a second terminal of the first switch. The analog front-end circuit is coupled to a second terminal of the first switch. A first terminal of the second switch is coupled to a corresponding fingerprint sensing line. The current or voltage source is coupled to a second terminal of the second switch.

[0005] In an embodiment of the present invention, the fingerprint sensing device described above senses a fingerprint on a display panel. The fingerprint sensing device includes a selection circuit and a fingerprint driving circuit. The selection circuit selects a fingerprint sensing area of ​​the display panel. Non-fingerprint sensing areas belong to at least a portion of the display panel but are not part of the fingerprint sensing area. The fingerprint driving circuit is coupled to multiple fingerprint sensing lines of the display panel. When the fingerprint driving circuit performs a fingerprint sensing operation, it keeps these fingerprint sensing lines in the non-fingerprint sensing areas in an electrically non-floating state.

[0006] In one embodiment of the present invention, the electronic device includes a display panel and a fingerprint sensing device. The display panel includes multiple fingerprint sensing lines. The fingerprint sensing device senses fingerprints on the display panel. The fingerprint sensing device includes a selection circuit and a fingerprint driving circuit. The selection circuit obtains the fingerprint sensing area corresponding to the touch area of ​​the display panel. Non-fingerprint sensing areas belong to at least a portion of the display panel but are not part of the fingerprint sensing areas. The fingerprint driving circuit is coupled to the fingerprint sensing lines of the display panel. When the fingerprint driving circuit performs a fingerprint sensing operation, the fingerprint driving circuit keeps the fingerprint sensing lines in the non-fingerprint sensing areas in an electrically non-floating state.

[0007] In one embodiment of the present invention, the operation method of the fingerprint sensing device includes: selecting a fingerprint sensing area corresponding to a touch area of ​​a display panel, wherein a non-fingerprint sensing area belongs to at least a portion of the display panel but does not belong to the fingerprint sensing area; performing fingerprint sensing operation on multiple fingerprint sensing lines in the fingerprint sensing area; and keeping the fingerprint sensing lines in the non-fingerprint sensing area in an electrically non-floating state when the fingerprint driving circuit performs fingerprint sensing operation on these fingerprint sensing lines in the fingerprint sensing area.

[0008] Based on the above, the fingerprint sensing device, fingerprint driving circuit, electronic device and fingerprint sensing device operation method described in the embodiments of the present invention can minimize display abnormalities in the non-fingerprint sensing area of ​​the display panel by keeping these fingerprint sensing lines in the non-fingerprint sensing area in an electrically non-floating state. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of a display panel and a driving circuit according to one embodiment.

[0010] Figure 2 This is a circuit block diagram of an electronic device according to an embodiment of the present invention.

[0011] Figure 3 This is a schematic flowchart illustrating the operation method of a fingerprint sensing device according to an embodiment of the present invention.

[0012] Figure 4 This is a circuit block diagram illustrating a fingerprint driving circuit according to an embodiment of the present invention.

[0013] Figure 5 This is a circuit block diagram illustrating a fingerprint sensing device according to another embodiment of the present invention.

[0014] Figure 6 This is a circuit block diagram illustrating a fingerprint sensing device according to another embodiment of the present invention.

[0015] Figure 7 This is a functional block diagram of an electronic device according to another embodiment of the present invention.

[0016] Explanation of reference numerals in the attached figures

[0017] 100, 200, 700: Electronic equipment

[0018] 110, 705: Fingerprint sensing area

[0019] 112: Display driver circuit

[0020] 119: Anti-floating circuit

[0021] 120, 704, 706: Non-fingerprint sensing areas

[0022] 130: Drive circuit

[0023] 140: Display panel

[0024] 200: Electronic equipment

[0025] 210, 211, 212, 703: Display Panel

[0026] 220, 500, 600: Fingerprint sensing devices

[0027] 221: Selection Circuit

[0028] 222, 400: Fingerprint driver circuit

[0029] 230: Fingerprint sensing unit pixels

[0030] 240, FSL: Fingerprint sensor cable

[0031] 410, 563, 663: Analog front-end circuits

[0032] 420: Current or voltage source

[0033] 510: Sensing Circuit

[0034] 518, 618, MUX1, MUX3: Switching circuits

[0035] 530: Transmission line

[0036] 701: Integrated Circuit FTDI

[0037] 702: Fingerprint Selection Switch

[0038] 707: Fingerprint Scanning Circuit

[0039] 708: N-channel analog front-end circuit and analog-to-digital converter

[0040] 709: Fingerprint Digital Circuit

[0041] 710: Serial Peripheral Interface

[0042] 711: System Application Processor

[0043] 712: Touch selector switch

[0044] 713: Touch Analog Front-End Circuit

[0045] 714: Sample and Hold Circuit

[0046] 715: Analog-to-Digital Converter

[0047] 716: Serial Peripheral Interface

[0048] FPR1: Fingerprint driver circuit

[0049] FS1, FS2, FS3, FS4, FSn: Sensing groups

[0050] IB: Current Source

[0051] IBIas: Bias Current

[0052] N1D, N1F: Selection Terminal

[0053] N2, N4: Shared solder pads

[0054] Rest: Reset signal

[0055] S310, S320, S330: Steps

[0056] SDL: Display data cable

[0057] Sel: Selection signal

[0058] SW, ZSW: Switches

[0059] SW1, SW3: Switching Units

[0060] TDDI: Display Driver Integrated Circuit

[0061] TR: Touch Area

[0062] VB: Voltage Source

[0063] VCOM: Common Voltage

[0064] VDD: Power supply voltage

[0065] Vout: Fingerprint sensing voltage Detailed Implementation

[0066] Reference will now be made in detail to exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same element symbols are used in the drawings and description to denote the same or similar parts.

[0067] The term "coupled (or connected)" as used throughout this application (including the claims) may refer to any direct or indirect connection means. For example, if the text describes a first device coupled (or connected) to a second device, it should be interpreted as the first device being directly connected to the second device, or the first device being indirectly connected to the second device through other devices or some connection means. The terms "first," "second," etc., used throughout this application (including the claims) are used to name components or distinguish different embodiments or scopes, and are not intended to limit the upper or lower limit of the number of components, nor to limit the order of components. Furthermore, wherever possible, components / components / steps using the same reference numerals in the drawings and embodiments represent the same or similar parts. Components / components / steps using the same reference numerals or the same terms in different embodiments can be referred to mutually in the relevant descriptions.

[0068] Figure 1 This is a schematic diagram of a display panel and a driving circuit according to one embodiment. Figure 1 The illustrated electronic device 100 can be any electronic device with display functionality, touch sensing functionality, and fingerprint sensing functionality. In one embodiment, the electronic device 100 can be (but is not limited to) a smartphone, a non-smartphone, a wearable electronic device, a tablet computer, a personal digital assistant, a laptop computer, or other independently operable electronic devices with display functionality, touch sensing functionality, and fingerprint sensing functionality. In another embodiment, the electronic device 100 can be (but is not limited to) a portable or non-portable electronic device in a vehicle intelligent system. In yet another embodiment, the electronic device 100 can be (but is not limited to) a smart home appliance, such as a television, computer, refrigerator, washing machine, telephone, induction cooker, table lamp, etc.

[0069] Figure 1 The illustrated electronic device 100 includes a driving circuit 130 and a display panel 140. The display panel 140 includes a touch sensor (not shown) and a fingerprint sensor. The driving circuit 130 can be coupled to the display panel 140. The driving circuit 130 is adapted to drive the display panel 140. The resolution of the illustrated display panel is, for example, 864*1920. The display panel has an array of display pixels (not shown), an array of touch sensors (not shown), and an array of fingerprint sensors. Figure 1The driving circuit 130 shown includes a touch with display driver integration (TDDI) circuit 132 and a fingerprint driver circuit FPR1. The TDDI circuit 132 can drive the display pixel array of the display panel 140 to display image frames. The TDDI circuit 132 can also drive the touch sensor array of the display panel to obtain touch frames. The fingerprint driver circuit FPR1 can drive the fingerprint sensor array of the display panel to obtain fingerprint frames.

[0070] When a finger touches the display panel, the TDDI circuit 132 detects the touch area TR and provides relevant information about the touch area TR to the fingerprint driving circuit FPR1. The fingerprint driving circuit FPR1 can temporarily divide the fingerprint sensing area of ​​the display panel 140 into at least a fingerprint sensing area 110 and a non-fingerprint sensing area 120 based on the touch area TR. The fingerprint sensing area 110 includes the touch area TR. The fingerprint driving circuit FPR1 can perform fingerprint sensing operations on the fingerprint sensing area 110 containing the touch area TR, but not on the non-fingerprint sensing area 120. In the non-fingerprint sensing area 120 where no fingerprint sensing operation is performed, the fingerprint sensing lines of the display panel 140 are electrically floating. Most lines are connected to a voltage source. When a line is not electrically connected to a voltage source, it is considered to be floating (electrically floating). Without such a connection, the voltage and current of this line are caused by an electromagnetic field or charge accumulation within the conductor, rather than by a voltage source. The fingerprint sensing line in the non-fingerprint sensing area 120 is easily affected by noise, which may cause the display panel 140 to malfunction in the non-fingerprint sensing area 120.

[0071] Figure 2 This is a circuit block diagram of an electronic device 200 according to an embodiment of the present invention. Figure 2 The illustrated electronic device 200 includes a display panel 210 and a fingerprint sensing device 220. The display panel 210 can be any display panel with fingerprint sensing functionality. This embodiment does not limit the structure of the display panel 210. Based on practical design, the display panel 210 can be a display panel with in-display fingerprint recognition functionality. For example, in some embodiments, the display panel 210 can be configured with a fingerprint sensor (not shown) containing multiple fingerprint sensing pixels. Based on practical design, the fingerprint sensor can be an optical fingerprint sensor or other fingerprint sensors, such as a capacitive fingerprint sensor. In some embodiments, Figure 2 The display panel 210 shown can be referenced. Figure 1 Description of the display panel 140 shown.

[0072] Touch circuitry (not shown) can perform touch sensing on display panel 210 to obtain a touch area TR corresponding to a finger on display panel 210. In some embodiments, the touch circuitry may refer to... Figure 1 The TDDI circuit 132 shown is described below. When a touch event occurs (i.e., a finger touches the display panel 210), the touch circuit can provide information about the touch area TR to the fingerprint sensing device 220.

[0073] The display panel 210 includes multiple fingerprint sensing lines, which can be divided into multiple sensing groups, such as... Figure 2 The sensor groups shown are FS1, FS2, FS3, FS4, ..., FSn. In Figure 2 In the illustrated embodiment, all fingerprint sensing pixels in the fingerprint sensing area of ​​the display panel 210 can be divided into multiple fingerprint sensing blocks. A fingerprint sensing device 220 is coupled to these fingerprint sensing lines of the display panel 210 to sense fingerprints on the display panel 210. Based on the touch area TR, the fingerprint sensing device 220 can temporarily divide the fingerprint sensing area of ​​the display panel 210 into at least a fingerprint sensing region (e.g., ...). Figure 2 The sensor groups FS3 and FS4 shown are different from the non-fingerprint sensing areas (e.g., fingerprint sensing areas). Figure 2 The sensor groups FS1, FS2, and FSn are shown. The non-fingerprint sensing area belongs to at least a portion of the display panel 210 but does not belong to the fingerprint sensing area.

[0074] Figure 3 This is a schematic flowchart illustrating the operation method of a fingerprint sensing device according to an embodiment of the present invention. Please refer to... Figure 2 and Figure 3 The fingerprint sensing device 220 includes a selection circuit 221 and a fingerprint driving circuit 222. In step S310, the selection circuit 221 can select the fingerprint sensing area (the sensing area corresponding to the touch area TR) of the display panel 210, for example... Figure 2 (Sensing groups FS3 and FS4 are shown). Selection circuit 221 can selectively couple the fingerprint sensing lines (i.e., sensing groups FS3 and FS4) in the fingerprint sensing area to fingerprint driving circuit 222.

[0075] The fingerprint driving circuit 222 can be coupled to multiple fingerprint sensing lines of the display panel 210. The fingerprint driving circuit 222 can perform fingerprint sensing operations using these fingerprint sensing lines in the fingerprint sensing area (step S320). Specifically, when the fingerprint driving circuit 222 performs fingerprint sensing operations using these fingerprint sensing lines in the fingerprint sensing area, the fingerprint driving circuit 222 can also perform fingerprint sensing operations in non-fingerprint sensing areas (e.g., ...). Figure 2The fingerprint sensing lines in the sensing groups FS1, FS2, and FSn shown are kept in an electrically non-floating state (step S330). When a line is electrically connected to a voltage source, the line is considered non-floating (electrically non-floating state). That is, the fingerprint driving circuit 222 can receive multiple sensing signals from multiple fingerprint sensing lines in the fingerprint sensing area to obtain fingerprint image data, but does not receive multiple sensing signals from fingerprint sensing lines in non-fingerprint sensing areas to obtain any fingerprint image data.

[0076] Figure 4 This is a circuit block diagram illustrating a fingerprint driving circuit 400 according to an embodiment of the present invention. Figure 2 The display panel 210 and fingerprint driver circuit 222 shown can be referenced. Figure 4 The description of the display panel 211 and the fingerprint driving circuit 400 shown, and / or Figure 4 The display panel 211 and fingerprint driver circuit 400 shown can be referenced. Figure 2 Description of the display panel 210 and the fingerprint driving circuit 222 shown. Figure 4 The display panel 211 shown has a fingerprint sensor array, which has multiple fingerprint sensing lines (e.g., fingerprint sensing lines 240) and multiple fingerprint sensing unit pixels (e.g., fingerprint sensing unit pixels 230). In each fingerprint sensing unit pixel 230, VDD represents the power supply voltage, Res represents the reset signal, VCOM represents the common voltage, and Sel represents the selection signal. The implementation of the fingerprint sensing unit pixel 230 should not be limited to... Figure 4 The circuit shown. According to actual design, in other embodiments, the fingerprint sensing unit pixel 230 may include known fingerprint sensing circuitry or other unit pixels.

[0077] Figure 4 The fingerprint driving circuit 400 shown includes a switch ZSW, a current source IBIas, an analog frontend (AFE) circuit 410, a switch SW, and a current or voltage source 420. A first terminal of the switch ZSW is adapted to be coupled to a corresponding fingerprint sensing line (e.g., fingerprint sensing line 240) among multiple fingerprint sensing lines on the display panel 211. The current source IBIas is coupled to a second terminal of the switch ZSW. The AFE circuit 410 corresponds to the fingerprint sensing line 240. The AFE circuit 410 is coupled to the second terminal of the switch ZSW. When the fingerprint sensing line 240 is within the fingerprint sensing area, the AFE circuit 410 can receive a sensing signal from the fingerprint sensing line 240 via the switch ZSW. When the fingerprint sensing line 240 is within a non-fingerprint sensing area, the AFE circuit 410 is not coupled to the fingerprint sensing line 240 and does not receive any sensing signal from the fingerprint sensing line 240.

[0078] The first terminal of switch SW is adapted to be coupled to the corresponding fingerprint sensing line (e.g., fingerprint sensing line 240). A current or voltage source 420 is coupled to the second terminal of switch SW. When fingerprint sensing unit pixel 230 and fingerprint sensing line 240 are within the fingerprint sensing area, switch ZSW is turned on, and switch SW is turned off. When fingerprint sensing line 240 is within the fingerprint sensing area, current or voltage source 420 is not coupled to fingerprint sensing line 240, and current source IBIas can bias fingerprint sensing line 240 so that fingerprint sensing unit pixel 230 can provide a sensing signal to AFE circuit 410. Therefore, AFE circuit 410 can read the sensing result (fingerprint sensing voltage Vout) of fingerprint sensing unit pixel 230.

[0079] When the fingerprint sensing unit pixel 230 and the fingerprint sensing line 240 are in a non-fingerprint sensing area, switch ZSW is off and switch SW is on. Therefore, when the fingerprint sensing line 240 is in a non-fingerprint sensing area, a current or voltage source 420 can be coupled to the fingerprint sensing line 240, so that the fingerprint sensing line 240 in the non-fingerprint sensing area remains electrically non-floating. Depending on the actual design, the current or voltage source 420 may include a current source, a voltage source, and / or other bias circuitry. When the current or voltage source 420 includes a current source, when the fingerprint sensing line 240 is in a non-fingerprint sensing area, the current or voltage source 420 can draw bias current from the fingerprint sensing line 240 (or provide bias current to the fingerprint sensing line 240) to keep the fingerprint sensing line 240 in an electrically non-floating state. In the case where the current or voltage source 420 includes a voltage source, when the fingerprint sensing line 240 is in a non-fingerprint sensing area, the current or voltage source 420 can provide a bias voltage (any fixed reference voltage, such as ground voltage) to the fingerprint sensing line 240 to keep the fingerprint sensing line 240 in an electrically non-floating state.

[0080] Figure 5 This is a circuit block diagram illustrating a fingerprint sensing device 500 according to another embodiment of the present invention. (See reference) Figure 5 The display panel 212 includes a switching unit SW3 and a shared pad N4. The switching unit SW3 includes multiple switching circuits, such as a switching circuit MUX3. Other switching circuits of the switching unit SW3 can be deduced by referring to the relevant description of the switching circuit MUX3, and will not be described in detail here. One selection terminal of the switching circuit MUX3 is coupled to a corresponding fingerprint sensing line (e.g., fingerprint sensing line FSL). Figure 5 The fingerprint sensor line FSL shown can be referenced. Figure 4 The relevant descriptions of the fingerprint sensing line 240 shown are analogous, so they will not be repeated here. Figure 5The other selection terminals of the switching circuit MUX3 shown are coupled to different display data lines SDL, such as... Figure 5 As shown. The common terminal of the switching circuit MUX3 is coupled to the shared pad N4.

[0081] Figure 2 The fingerprint sensing device 220 shown can be referred to Figure 5 The description of the fingerprint sensing device 500 shown, and / or Figure 5 The fingerprint sensing device 500 shown can be referenced. Figure 2 Description of the fingerprint sensing device 220 shown. Figure 5 The fingerprint sensing device 500 shown includes a shared pad N2, a switching unit SW1, a sensing circuit 510, and an anti-float circuit 119. The shared pad N2 is adapted to be coupled to a shared pad N4 via a transmission line 530. The switching unit SW1 includes multiple switching circuits, such as a switching circuit MUX1. Other switching circuits of the switching unit SW1 can be deduced by referring to the relevant description of the switching circuit MUX1, and therefore will not be described in detail. The common terminal of the switching circuit MUX1 is coupled to the shared pad N2. The sensing circuit 510 and the anti-float circuit 119 are coupled to one selection terminal N1F of the switching circuit MUX1, while the display driving circuit 112 is coupled to another selection terminal N1D of the switching circuit MUX1. When the corresponding fingerprint sensing line (e.g., fingerprint sensing line FSL) belongs to the fingerprint sensing area, the sensing circuit 510 can perform fingerprint sensing operation on the fingerprint sensing line FSL through the switching circuit MUX1, the shared pad N2, the shared pad N4, and the switching circuit MUX3.

[0082] Figure 5 The sensing circuit 510 shown includes a switching circuit 518 and an AFE circuit 563. Multiple selection terminals of the switching circuit 518 are respectively coupled to a selection terminal of a different switching circuit MUX1 of the switching unit SW1, while the common terminal of the switching circuit 518 is coupled to the AFE circuit 563. Figure 5 The switching circuit 518 and AFE circuit 563 shown can be referred to Figure 4 The related descriptions of switch ZSW and AFE circuit 410 shown are analogous and will not be repeated here. Switching unit SW1 and switching circuit 518 can be used as... Figure 2 The components of the selection circuit 221 are shown, while the anti-float circuit 119 and the AFE circuit 563 can be used as... Figure 2 The components of the fingerprint driving circuit 222 shown.

[0083] The anti-floating circuit 119 is coupled to the selection terminal of the second switching circuit. When the corresponding fingerprint sensing line (e.g., fingerprint sensing line FSL) is in a non-fingerprint sensing area, the anti-floating circuit 119 keeps the corresponding fingerprint sensing line FSL in an electrically non-floating state. For example, when the fingerprint sensing line FSL is in the fingerprint sensing area, the anti-floating circuit 119 is disabled; when the fingerprint sensing line FSL is in a non-fingerprint sensing area, the anti-floating circuit 119 is enabled, so that the fingerprint sensing line FSL is kept in an electrically non-floating state.

[0084] In some embodiments, the anti-float circuit 119 may include a switch (not shown). Figure 5 ) and current or voltage sources (not shown in Figure 5 The first terminal of the switch is coupled to the selection terminal of the switching circuit MUX1. The current or voltage source is coupled to the second terminal of the switch. The current or voltage source can provide a reference current to the corresponding fingerprint sensing line FSL through the switch, switching circuit MUX1, shared pad N2, shared pad N4 and switching circuit MUX3, so that the fingerprint sensing line FSL is kept in an electrically non-floating state. Figure 5 The switch and the current or voltage source of the anti-floating circuit 119 shown can be referenced. Figure 4 The relevant descriptions of the switch SW and the current or voltage source 420 shown are analogous, so they will not be repeated here.

[0085] Figure 6 This is a circuit block diagram illustrating a fingerprint sensing device 600 according to another embodiment of the present invention. Figure 2 The fingerprint sensing device 220 shown can be referred to Figure 6 The description of the fingerprint sensing device 600 shown, and / or Figure 6 The fingerprint sensing device 600 shown can be referenced. Figure 2 Description of the fingerprint sensing device 220 shown. Figure 6 The fingerprint sensing device 600 shown includes a shared solder pad N2, an anti-float circuit 119, a switching unit SW2, a display driving circuit 112, a switching circuit 618, and an AFE circuit 663. Figure 6 The fingerprint sensing device 220, shared solder pad N2, anti-float circuit 119, switching unit SW2, display driver circuit 112, switching circuit 618, and AFE circuit 663 shown can be referenced. Figure 5 The descriptions of the fingerprint sensing device 500, shared solder pad N2, anti-float circuit 119, switching unit SW1, display driver circuit 112, switching circuit 518, and AFE circuit 563 shown are omitted here. Figure 6 In the illustrated embodiment, the anti-float circuit 119 is coupled to the shared solder pad N2. When the corresponding fingerprint sensing line (e.g.) Figure 5When the fingerprint sensing line (FSL) shown belongs to a non-fingerprint sensing area, the anti-floating circuit 119 can keep the corresponding fingerprint sensing line in an electrically non-floating state.

[0086] Figure 7 This is a functional block diagram of an electronic device 700 according to another embodiment of the present invention. Figure 7 The electronic device 700 shown includes an integrated circuit FTDI 701, a display panel 703 and a system application processor 711. The display panel 703 can be any display panel with fingerprint sensing function. Figure 7 The display panel 703 shown includes a fingerprint scanning circuit 707 and 1080 fingerprint sensing lines. These 1080 fingerprint sensing lines comprise a fingerprint sensing area 705 and non-fingerprint sensing areas 704 and 706. Fingerprint sensing lines 1-200 belong to non-fingerprint sensing area 704, lines 301-1080 belong to non-fingerprint sensing area 706, and lines 201-300 belong to fingerprint sensing area 705. Any of these 1080 fingerprint sensing lines of the display panel 703 can be referenced... Figure 4 The related descriptions of the fingerprint sensing line 240 shown are analogous and will not be repeated here. The integrated circuit FTDI 701 includes a touch selection switch 712, a touch analog front-end circuit 713, a sample-and-hold circuit 714, an analog-to-digital converter 715, a serial peripheral interface 716, a fingerprint driver circuit FPR1, a fingerprint selection switch 702, an N-channel analog front-end circuit and analog-to-digital converter 708, a fingerprint digital circuit 709, and a serial peripheral interface 710. Depending on the actual design, the touch sensing circuit including the selection switch 712, the touch analog front-end circuit 713, the sample-and-hold circuit 714, the analog-to-digital converter 715, and the serial peripheral interface 716 can be a general touch sensing circuit or other touch sensing circuits, which will not be elaborated here.

[0087] The integrated circuit FTDI 701 can perform fingerprint frame capture operations on the fingerprint sensing lines of the fingerprint sensing area 705 selected by the fingerprint selection switch 702. The fingerprint digital circuit 709 can read the fingerprint frame capture result (fingerprint frame) via the N-channel analog front-end circuit and analog-to-digital converter 708, and then transmit the fingerprint frame capture result to the external system application processor 711 via the serial peripheral interface 710. The integrated circuit FTDI 701 can prevent floating connections (not shown) from occurring on any of the 1080 fingerprint sensing lines that belong to non-fingerprint sensing areas 704 and 706 (i.e., fingerprint sensing lines not selected by the fingerprint selection switch 702). Figure 7 You can refer to Figure 4 The relevant instructions for the current or voltage source 420 shown can be used as a reference, or you can refer to... Figure 5(The relevant description of the anti-floating circuit 119 shown in Figure 6 can be used as a deduction) to draw current or apply voltage.

[0088] In summary, the fingerprint sensing device, fingerprint driving circuit, electronic device, and operation method of the fingerprint sensing device described in the embodiments of the present invention can minimize display abnormalities in the non-fingerprint sensing area of ​​the display panel by keeping the fingerprint sensing lines in the non-fingerprint sensing area in an electrically non-floating state.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fingerprint sensing device for sensing fingerprints on a display panel, characterized in that, The fingerprint sensing device includes: The selection circuit selects the fingerprint sensing area of ​​the display panel, wherein the non-fingerprint sensing area belongs to at least a portion of the display panel but does not belong to the fingerprint sensing area; and A fingerprint driving circuit is coupled to multiple fingerprint sensing lines of the display panel, wherein when the fingerprint driving circuit performs a fingerprint sensing operation, the fingerprint driving circuit keeps the multiple fingerprint sensing lines in the non-fingerprint sensing area in an electrically non-floating state.

2. The fingerprint sensing device according to claim 1, characterized in that, The fingerprint sensing area corresponds to the touch area of ​​the display panel.

3. The fingerprint sensing device according to claim 1, characterized in that, The fingerprint driving circuit receives multiple sensing signals from the multiple fingerprint sensing lines in the fingerprint sensing area to obtain fingerprint image data, but does not receive multiple sensing signals from the multiple fingerprint sensing lines in the non-fingerprint sensing area to obtain any fingerprint image data.

4. The fingerprint sensing device according to claim 1, characterized in that, The fingerprint driving circuit further includes an analog front-end circuit, wherein the analog front-end circuit is coupled to a first fingerprint sensing line belonging to the fingerprint sensing area.

5. The fingerprint sensing device according to claim 1, characterized in that, The fingerprint driving circuit includes an analog front-end circuit and a switch coupled between at least one corresponding fingerprint sensing line and the analog front-end circuit, wherein the switch is turned on and off when the at least one corresponding fingerprint sensing line is located in the fingerprint sensing area and the non-fingerprint sensing area, respectively.

6. The fingerprint sensing device according to claim 1, characterized in that, The fingerprint driving circuit further includes a current or voltage source corresponding to at least one first fingerprint sensing line, and when the at least one first fingerprint sensing line is located in the non-fingerprint sensing area, the current or voltage source is coupled to the at least one first fingerprint sensing line, and the at least one first fingerprint sensing line in the non-fingerprint sensing area remains in the electrically non-floating state.

7. The fingerprint sensing device according to claim 6, characterized in that, When the at least one first fingerprint sensing line is in the non-fingerprint sensing area, the at least one first fingerprint sensing line is coupled to the current source of the fingerprint driving circuit.

8. The fingerprint sensing device according to claim 6, characterized in that, When the at least one first fingerprint sensing line is in the non-fingerprint sensing area, the at least one first fingerprint sensing line is coupled to the voltage source of the fingerprint driving circuit.

9. The fingerprint sensing device according to claim 1, characterized in that, The fingerprint driving circuit includes: A first switch has a first end coupled to a corresponding fingerprint sensing line among the plurality of fingerprint sensing lines on the display panel; A current source is coupled to the second terminal of the first switch; The analog front-end circuit is coupled to the second terminal of the first switch; The second switch has a first end coupled to the corresponding fingerprint sensing line; and A current or voltage source is coupled to the second terminal of the second switch.

10. The fingerprint sensing device according to claim 9, characterized in that, When the corresponding fingerprint sensing line belongs to the non-fingerprint sensing area, the current or voltage source keeps the corresponding fingerprint sensing line in the electrically non-floating state.

11. The fingerprint sensing device according to claim 9, characterized in that, When the corresponding fingerprint sensing line belongs to the fingerprint sensing area, the first switch is turned on; and when the corresponding fingerprint sensing line belongs to the non-fingerprint sensing area, the first switch is turned off.

12. The fingerprint sensing device according to claim 9, characterized in that, When the corresponding fingerprint sensing line belongs to the fingerprint sensing area, the second switch is off; and when the corresponding fingerprint sensing line belongs to the non-fingerprint sensing area, the second switch is on.

13. The fingerprint sensing device according to claim 1, characterized in that, The display panel includes a first switching circuit and a first shared solder pad. The selection terminal of the first switching circuit is coupled to a corresponding fingerprint sensing line among the plurality of fingerprint sensing lines, and the common terminal of the first switching circuit is coupled to the first shared solder pad. The fingerprint driving circuit includes: The second shared pad is coupled to the first shared pad; The second switching circuit has a common terminal coupled to the second shared pad; A sensing circuit, coupled to the selection terminal of the second switching circuit, performs fingerprint sensing operation on the corresponding fingerprint sensing line when the corresponding fingerprint sensing line belongs to the fingerprint sensing area through the second switching circuit, the second shared pad, the first shared pad, and the first switching circuit; and An anti-floating circuit is coupled to the selection terminal of the second switching circuit. When the corresponding fingerprint sensing line belongs to the non-fingerprint sensing area, the corresponding fingerprint sensing line is kept in the electrically non-floating state.

14. The fingerprint sensing device according to claim 13, characterized in that, When the corresponding fingerprint sensing line belongs to the fingerprint sensing area, the anti-floating circuit is disabled, and when the corresponding fingerprint sensing line belongs to the non-fingerprint sensing area, the anti-floating circuit is enabled to keep the corresponding fingerprint sensing line in the electrically non-floating state.

15. The fingerprint sensing device according to claim 13, characterized in that, The anti-floating connection circuit includes: A switch having a first terminal coupled to the selection terminal of the second switching circuit; and A current or voltage source is coupled to the second terminal of the switch, and provides a reference current to the corresponding fingerprint sensing line through the switch, the second switching circuit, the second shared pad, the first shared pad, and the first switching circuit, so that the corresponding fingerprint sensing line is kept in the electrically non-floating state.

16. The fingerprint sensing device according to claim 15, characterized in that, When the corresponding fingerprint sensing line belongs to the fingerprint sensing area, the switch is off; when the corresponding fingerprint sensing line belongs to the non-fingerprint sensing area, the switch is on.

17. The fingerprint sensing device according to claim 1, characterized in that, The display panel includes a first switching circuit and a first shared solder pad. The selection terminal of the first switching circuit is coupled to a corresponding fingerprint sensing line among the plurality of fingerprint sensing lines, and the common terminal of the first switching circuit is coupled to the first shared solder pad. The fingerprint driving circuit includes: The second shared pad is coupled to the first shared pad; The second switching circuit has a common terminal coupled to the second shared pad; A sensing circuit, coupled to the selection terminal of the second switching circuit, performs the fingerprint sensing operation on the corresponding fingerprint sensing line through the second switching circuit, the second shared pad, the first shared pad, and the first switching circuit when the corresponding fingerprint sensing line belongs to the fingerprint sensing area; and An anti-floating circuit, coupled to the second shared pad, keeps the corresponding fingerprint sensing line in the electrically non-floating state when the corresponding fingerprint sensing line belongs to the non-fingerprint sensing area.

18. The fingerprint sensing device according to claim 17, characterized in that, When the corresponding fingerprint sensing line belongs to the fingerprint sensing area, the anti-floating circuit is disabled, and when the corresponding fingerprint sensing line belongs to the non-fingerprint sensing area, the anti-floating circuit is enabled to keep the corresponding fingerprint sensing line in the electrically non-floating state.

19. A fingerprint driving circuit, characterized in that, The fingerprint driving circuit includes: A first switch has a first end coupled to a corresponding fingerprint sensing line among a plurality of fingerprint sensing lines on a display panel; A current source is coupled to the second terminal of the first switch; The analog front-end circuit is coupled to the second terminal of the first switch; The second switch has a first end coupled to the corresponding fingerprint sensing line; and A current or voltage source is coupled to the second terminal of the second switch, wherein... When the corresponding fingerprint sensing line belongs to a non-fingerprint sensing area, the current or voltage source keeps the corresponding fingerprint sensing line in an electrically non-floating state.

20. A fingerprint driving circuit, characterized in that, The fingerprint driving circuit includes: A first switch has a first end coupled to a corresponding fingerprint sensing line among a plurality of fingerprint sensing lines on a display panel; A current source is coupled to the second terminal of the first switch; The analog front-end circuit is coupled to the second terminal of the first switch; The second switch has a first end coupled to the corresponding fingerprint sensing line; and A current or voltage source is coupled to the second terminal of the second switch, wherein... When the corresponding fingerprint sensing line belongs to the fingerprint sensing area, the current source biases the corresponding fingerprint sensing line.

21. A fingerprint driving circuit, characterized in that, The fingerprint driving circuit includes: A first switch has a first end coupled to a corresponding fingerprint sensing line among a plurality of fingerprint sensing lines on a display panel; A current source is coupled to the second terminal of the first switch; The analog front-end circuit is coupled to the second terminal of the first switch; The second switch has a first end coupled to the corresponding fingerprint sensing line; and A current or voltage source is coupled to the second terminal of the second switch, wherein... When the corresponding fingerprint sensing line belongs to the fingerprint sensing area, the first switch is turned on; and When the corresponding fingerprint sensing line belongs to a non-fingerprint sensing area, the first switch is turned off.

22. A fingerprint driving circuit, characterized in that, The fingerprint driving circuit includes: A first switch has a first end coupled to a corresponding fingerprint sensing line among a plurality of fingerprint sensing lines on a display panel; A current source is coupled to the second terminal of the first switch; The analog front-end circuit is coupled to the second terminal of the first switch; The second switch has a first end coupled to the corresponding fingerprint sensing line; and A current or voltage source is coupled to the second terminal of the second switch, wherein... When the corresponding fingerprint sensing line belongs to the fingerprint sensing area, the second switch is off; and When the corresponding fingerprint sensing line belongs to a non-fingerprint sensing area, the second switch is turned on.

23. An electronic device, characterized in that, The electronic device includes: The display panel includes multiple fingerprint sensing lines; and A fingerprint sensing device for sensing fingerprints on the display panel, wherein the fingerprint sensing device includes: The selection circuit obtains the fingerprint sensing area corresponding to the touch area of ​​the display panel, wherein the non-fingerprint sensing area belongs to at least a portion of the display panel but does not belong to the fingerprint sensing area; and A fingerprint driving circuit is coupled to the plurality of fingerprint sensing lines of the display panel, wherein when the fingerprint driving circuit performs a fingerprint sensing operation, the fingerprint driving circuit keeps the plurality of fingerprint sensing lines in the non-fingerprint sensing area in an electrically non-floating state.

24. A method for operating a fingerprint sensing device, characterized in that, The operation method includes: Select the fingerprint sensing area corresponding to the touch area of ​​the display panel, wherein the non-fingerprint sensing area belongs to at least a part of the display panel but does not belong to the fingerprint sensing area; Fingerprint sensing operations are performed on multiple fingerprint sensing lines in the fingerprint sensing area; and When performing the fingerprint sensing operation on the plurality of fingerprint sensing lines in the fingerprint sensing area, the plurality of fingerprint sensing lines in the non-fingerprint sensing area are kept in an electrically non-floating state.

25. The operating method according to claim 24, characterized in that, The operation method further includes: When performing the fingerprint sensing operation on the corresponding fingerprint sensing line, a first current is provided to the corresponding fingerprint sensing line through a first switch, and the fingerprint sensing operation is performed on the corresponding fingerprint sensing line by the analog front-end circuit through the first switch. When the corresponding fingerprint sensing line belongs to the non-fingerprint sensing area, the first switch is turned off; When the corresponding fingerprint sensing line belongs to the non-fingerprint sensing area, a current or voltage source provides a second current to the corresponding fingerprint sensing line through a second switch, so that the corresponding fingerprint sensing line remains in the electrically non-floating state; and When performing the fingerprint sensing operation on the corresponding fingerprint sensing line, the second switch is turned off.

26. The operating method according to claim 24, characterized in that, The operation method further includes: When performing the fingerprint sensing operation on the corresponding fingerprint sensing line, a current source provides a reference current to the corresponding fingerprint sensing line among the multiple fingerprint sensing lines through a first switch, and an analog front-end circuit performs the fingerprint sensing operation on the corresponding fingerprint sensing line through the first switch. When the corresponding fingerprint sensing line belongs to the non-fingerprint sensing area, the first switch is turned off; When the corresponding fingerprint sensing line belongs to the non-fingerprint sensing area, a reference voltage is provided to the corresponding fingerprint sensing line by a current or voltage source through a second switch, so that the corresponding fingerprint sensing line remains in the electrically non-floating state; and When performing the fingerprint sensing operation on the corresponding fingerprint sensing line, the second switch is turned off.

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