Full-screen fingerprint sensing panel and display device

Abstract

The invention relates to the technical field of display, and provides a full-screen fingerprint sensing panel and a display device. The full-screen fingerprint sensing panel comprises pixel units distributed all over a display area, wherein each pixel unit comprises a sensing sub-pixel; the fingerprint sensing chip is connected with each column of sensing sub-pixels through sensing data lines; and the adder is connected between the sensing sub-pixels and the fingerprint sensing chip, and the adder carries out grouping operation on output signals of each column of sensing sub-pixels and then transmits the output signals to the fingerprint sensing chip. According to the full-screen fingerprint sensing panel, grouping operation is carried out on the output signals of the full-screen sensing sub-pixels according to columns through the summator, the difference between the output signals of the sensing sub-pixels caused by the factor that the electrical property of a device is unstable can be overcome, the misjudgment rate of a fingerprint sensing chip on the fingerprint sensing signals is reduced, and the fingerprint recognition accuracy of the full-screen fingerprint sensing panel is improved.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a full-screen fingerprint sensing panel and a display device. Background Art

[0002] With the development of display technology, full-screen fingerprint sensing panels have gradually developed. A full-screen fingerprint sensing panel is a display panel with a full-screen fingerprint sensing function, which allows users to unlock their fingerprints within the full screen range, which can improve the convenience of fingerprint unlocking operations and enhance user experience.

[0003] To achieve full-screen fingerprint sensing, fingerprint sensing pixels are usually set up in the full screen range, and each fingerprint sensing pixel is driven by a sensing circuit. The sensing circuit includes a driving transistor and a photosensitive element. Due to the instability of the threshold voltage of the driving transistor, the current passing through the photosensitive element is unstable, resulting in large differences in the output current of different fingerprint sensing pixels; this difference can easily cause misjudgment of the touch panel signal.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0005] In view of this, the present invention provides a full-screen fingerprint sensing panel and a display device, which group the output signals of the full-screen sensing sub-pixels by column through an adder, thereby overcoming the differences between the output signals of the sensing sub-pixels caused by the electrical instability of the device, reducing the misjudgment rate of the fingerprint sensing signal by the fingerprint sensing chip, and improving the fingerprint recognition accuracy of the full-screen fingerprint sensing panel.

[0006] According to one aspect of the present invention, there is provided a full-screen fingerprint sensing panel, comprising: pixel units distributed throughout a display area, each of the pixel units comprising a sensing sub-pixel; a fingerprint sensing chip, connecting each column of sensing sub-pixels via a sensing data line; an adder, connected between the sensing sub-pixels and the fingerprint sensing chip, the adder performing group operations on output signals of the sensing sub-pixels in each column and transmitting the signals to the fingerprint sensing chip.

[0007] In some embodiments, the adder performs group operations on the output signals of each column of the sensing sub-pixels, so that the number of columns of each group of sensing sub-pixels is continuous, the number of columns of each group of sensing sub-pixels is the same, and the output signals of each group of sensing sub-pixels are operated in the same manner.

[0008] In some embodiments, the operation method includes one or more of addition, subtraction, multiplication and division.

[0009] In some embodiments, the sensing circuit of each of the sensing sub-pixels includes: a first switching transistor and a storage capacitor connected in series between a first voltage signal and a second voltage signal; a driving transistor and a second switching transistor connected in series between the first voltage signal and an output terminal; a photodiode, wherein a first electrode of the photodiode receives a voltage signal, and a second electrode is connected to a gate of the driving transistor via a series node between the first switching transistor and the storage capacitor; wherein the gate of the first switching transistor receives a reset signal, and the gate of the second switching transistor receives a row selection signal.

[0010] In some embodiments, the photodiode is reverse biased, an anode of the photodiode receives the second voltage signal, and a cathode of the photodiode is connected to the series node.

[0011] In some embodiments, the reset signal and the row selection signal come from a sensing pixel scanning circuit, the sensing pixel scanning circuit connects each row of sensing sub-pixels through a sensing scanning line, and the sensing pixel scanning circuit is arranged on both sides of the display area.

[0012] In some embodiments, each of the pixel units further includes a light-emitting sub-pixel; the full-screen fingerprint sensing panel further includes a panel driver chip, and the panel driver chip is connected to each column of light-emitting sub-pixels through pixel data lines.

[0013] In some embodiments, the full-screen fingerprint sensing panel further includes: a multiplexing circuit, wherein the sensing data line derived from the sensing sub-pixel is connected to the fingerprint sensing chip via the adder, and the pixel data line derived from the light-emitting sub-pixel is connected to the panel driving chip via the multiplexing circuit.

[0014] In some embodiments, the full-screen fingerprint sensing panel further includes: a luminous pixel scanning circuit, which connects each row of luminous sub-pixels through a pixel scanning line, and the luminous pixel scanning circuit is arranged on both sides of the display area.

[0015] According to yet another aspect of the present invention, a display device is provided, wherein the display device is configured with the full-screen fingerprint sensing panel as described in any of the above embodiments.

[0016] The beneficial effects of the present invention compared with the prior art include at least:

[0017] The full-screen fingerprint sensing panel and display device of the present invention perform group operations on the output signals of the full-screen sensing sub-pixels by columns through an adder, thereby eliminating the difference between the output signals of the sensing sub-pixels caused by the uneven threshold voltages of the driving transistors of the sensing sub-pixels, so that the fingerprint sensing chip performs fingerprint recognition based on the current signal after the group operation of the adder, which can reduce the misjudgment rate of the fingerprint sensing chip for the fingerprint sensing signal and improve the fingerprint recognition accuracy of the full-screen fingerprint sensing panel.

[0018] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings herein are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present invention, and together with the specification are used to explain the principles of the present invention. Obviously, the accompanying drawings described below are only some embodiments of the present invention, and for those of ordinary skill in the art, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0020] Figure 1 A schematic diagram showing the structural principle of a full-screen fingerprint sensing panel in an embodiment of the present invention is shown;

[0021] Figure 2 A schematic diagram showing the structural principle of a conventional general sensing circuit is shown;

[0022] Figure 3 A schematic diagram of the driving architecture of a full-screen fingerprint sensing panel in an embodiment of the present invention is shown;

[0023] Figure 4 A schematic diagram of a driving architecture of a full-screen fingerprint sensing panel in yet another embodiment of the present invention is shown. DETAILED DESCRIPTION

[0024] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein. Instead, these embodiments are provided to make the present invention comprehensive and complete and to fully convey the concepts of the example embodiments to those skilled in the art.

[0025] The accompanying drawings are only schematic illustrations of the present invention and are not necessarily drawn to scale. The same reference numerals in the figures represent the same or similar parts, and their repeated description will be omitted. Some of the block diagrams shown in the accompanying drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0026] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "up", "down", "left", "right", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0027] It should be noted that, in the absence of conflict, the embodiments of the present invention and features in different embodiments may be combined with each other.

[0028] Figure 1 The structural principle of the full-screen fingerprint sensing panel in the embodiment of the present invention is shown; Figure 1 As shown, the full-screen fingerprint sensing panel provided by the embodiment of the present invention includes:

[0029] Pixel units distributed throughout the display area 10, each pixel unit including a sensing sub-pixel 22;

[0030] The fingerprint sensing chip 40 is connected to each column of sensing sub-pixels 22 via sensing data lines 22a;

[0031] The adder 30 is connected between the sensing sub-pixels 22 and the fingerprint sensing chip 40 . The adder 30 performs grouping operations on the output signals of the sensing sub-pixels 22 in each column and transmits the signals to the fingerprint sensing chip 40 .

[0032] The full-screen fingerprint sensing panel of the present invention is an In-display fingerprint sensing panel, and its sensing sub-pixel 22 is built into the display screen. Each sensing sub-pixel 22 is driven by a corresponding driving transistor. Due to the electrical instability of the device, that is, the instability of the threshold voltage of the driving transistor of the sensing sub-pixel 22, the output signals of each sensing sub-pixel 22 are greatly different from each other, which can easily cause misjudgment of the fingerprint sensing chip 40. For a touch sensing panel, its photosensitive component must be able to distinguish sufficient current difference between light and dark illumination, and convert it into sufficient potential difference through the next-level converter to distinguish the signal of the touch panel.

[0033] The full-screen fingerprint sensing panel of the present invention uses an adder 30 to perform group operations on the output signals of the full-screen sensing sub-pixels 22 by column, that is, before entering the fingerprint sensing chip 40 for interpretation, the adder 30 is first used to perform group operations on the output signals of the full-screen sensing sub-pixels 22, which can overcome the increase in the amount of current variation outputted by the sensing sub-pixels 22 due to the electrical instability of the device (mainly referring to the instability of the threshold voltage of the driving transistor of the sensing sub-pixel 22), eliminate the difference caused by the uneven threshold voltage of the driving transistor of each sensing sub-pixel 22, and reduce the misjudgment rate of the fingerprint sensing chip 40 for the fingerprint sensing signal, thereby improving the fingerprint recognition accuracy of the full-screen fingerprint sensing panel.

[0034] The output signal of the sensing sub-pixel 22 specifically refers to the output current value. The technology of fingerprint sensing chip 40 performing fingerprint recognition based on the output signal of the sensing sub-pixel 22 is already available, and the present invention does not limit this. In the present invention, when a fingerprint matching request is issued, the touch control locates the finger position, and its coordinates are fed back to the fingerprint recognition module. The fingerprint recognition module scans the fingerprint position, and the fingerprint sensing chip 40 performs fingerprint recognition based on the output signal after the grouping operation of the adder 30. The scanned fingerprint is matched with the original fingerprint, and a decision is made based on this whether to unlock the full-screen fingerprint sensing panel.

[0035] In some embodiments, the adder 30 performs group operations on the output signals of each column of sensing sub-pixels 22, so that the number of columns of each group of sensing sub-pixels 22 is continuous, the number of columns of each group of sensing sub-pixels 22 is the same, and the output signals of each group of sensing sub-pixels 22 are operated in the same manner.

[0036] By operating the output signals of n consecutive columns (n ​​is a positive integer greater than or equal to 2) of sensing sub-pixels 22 using the adder 30 (the sensing sub-pixels 22 are scanned row by row, so the adder 30 actually operates the output signals of n consecutive columns of sensing sub-pixels 22 in the same row), the output signal difference caused by the uneven threshold voltage of the driving transistor of the sensing sub-pixel 22 can be eliminated, and the output signals of each group of sensing sub-pixels 22 are operated in the same way, so that the fingerprint sensing chip 40 can perform correct fingerprint recognition based on the current signal after the grouping operation of the adder 30.

[0037] In some embodiments, the operation mode of the adder 30 on the output signals of the plurality of sensing sub-pixels 22 can be set to include any one or more of addition, subtraction, multiplication and division as required.

[0038] Figure 2 Shows the structural principle of a general active sensing circuit; combined Figure 1 and Figure 2 As shown, the sensing circuit of each sensing sub-pixel 22 includes:

[0039] A first switch transistor M1 and a storage capacitor Cst are connected in series between a first voltage signal VDD and a second voltage signal (the second voltage signal is grounded in this embodiment);

[0040] A driving transistor M2 and a second switch transistor M3 connected in series between the first voltage signal VDD and the output terminal;

[0041] A photodiode PD, wherein a first electrode of the photodiode PD receives a voltage signal, and a second electrode of the photodiode PD is connected to a gate of a driving transistor M2 via a series node Vc of a first switching transistor M1 and a storage capacitor Cst;

[0042] The gate of the first switch transistor M1 receives a reset signal reset, and the gate of the second switch transistor M3 receives a row selection signal Row-Select.

[0043] In some embodiments, the photodiode PD is reverse biased, its anode receives the second voltage signal, and its cathode is connected to the series node Vc. When the photodiode PD is reverse biased, its built-in voltage can be enhanced, so that when light shines on the photodiode PD, the photogenerated carriers drift more easily, thereby improving the frequency characteristics of the device.

[0044] The reset signal reset is used to initialize the series node Vc. When the reset signal reset is a high level signal, the first switch transistor M1 is turned on and the storage capacitor Cst is charged. When a touch occurs at some sensing sub-pixels 22, the corresponding photodiode PD receives reflected light (the light emitted by the light-emitting sub-pixel of the pixel unit is reflected to the photodiode PD by the finger), and the light sensing generates a photocurrent to discharge the storage capacitor Cst; at this time, if the second switch transistor M3 is turned on under the row selection signal Row-Select, the driving transistor M2 works in the saturation region, and the output voltage Vout is related to the threshold voltage of the driving transistor M2.

[0045] Figure 2 Specifically shown is a 3T1C driving circuit. In other embodiments, the sensing circuit of the sensing sub-pixel 22 may also adopt other suitable driving circuit structures; regardless of how the driving circuit structure changes, when a touch occurs at the corresponding sensing sub-pixel 22, its sensing circuit will output an output signal related to the threshold voltage of the driving transistor. The present invention operates the output signals of the sensing sub-pixels 22 of n consecutive columns through the adder 30, which can reduce the influence of the output signal difference of different sensing sub-pixels 22 caused by the uneven threshold voltage of the driving transistor on fingerprint recognition, so that the fingerprint sensing chip 40 can perform effective fingerprint recognition based on the output signal after the grouping operation of the adder 30.

[0046] Figure 3The driving architecture of the full-screen fingerprint sensing panel in the embodiment of the present invention is shown; Figures 1 to 3 As shown, in some embodiments, the row selection signal Row-Select of the second switching transistor M3 for controlling the sensing sub-pixel 22 and the reset signal reset of the first switching transistor M1 come from the sensing pixel scanning circuit 52. The sensing pixel scanning circuit 52 is connected to each row of sensing sub-pixels 22 through a sensing scanning line (not specifically shown in the figure), and the sensing pixel scanning circuit 52 is arranged on both sides of the display area 10.

[0047] The sensing pixel scanning circuit 52 may specifically be a sensing GOA circuit (Gate on Array), which is disposed on the left and right sides of the display area 10 and is respectively connected to each row of sensing sub-pixels 22 to scan the sensing sub-pixels 22 row by row.

[0048] Continue to combine Figures 1 to 3 As shown, in some embodiments, each pixel unit also includes a light-emitting sub-pixel; the full-screen fingerprint sensing panel also includes a panel driver chip 62, and the panel driver chip 62 is connected to each column of light-emitting sub-pixels through a pixel data line 621.

[0049] The light-emitting sub-pixels are used to realize the light-emitting display of the full-screen fingerprint sensing panel. The light-emitting sub-pixels specifically include red light-emitting sub-pixels 20a, green light-emitting sub-pixels 20b, and blue light-emitting sub-pixels 20c. The panel driver chip 62 can use an existing driver IC, and its structure and principle will not be described in detail.

[0050] In some embodiments, the full-screen fingerprint sensing panel also includes: a multiplexing circuit 70, and the pixel data lines 621 derived from the light-emitting sub-pixels (including the red sub-pixel data line 621a corresponding to the red light-emitting sub-pixel 20a and the green sub-pixel data line 621b corresponding to the green light-emitting sub-pixel 20b) are connected to the panel driving chip 62 via the multiplexing circuit 70.

[0051] The multiplexing circuit 70 can simplify the circuit design below the display area 10 . The structure and principle of the multiplexing circuit 70 are already known and will not be described in detail.

[0052] In addition, it should be noted that the sensing data lines 22 a derived from the sensing sub-pixels 22 are connected to the fingerprint sensing chip 40 through the data lines 401 after being grouped and calculated by the adder 30 .

[0053] In some embodiments, the full-screen fingerprint sensing panel also includes: a luminous pixel scanning circuit 55, which connects each row of luminous sub-pixels through a pixel scanning line (not specifically shown in the figure), and the luminous pixel scanning circuit 55 is arranged on both sides of the display area 10.

[0054] The luminous pixel scanning circuit 55 may specifically be a luminous pixel GEOA circuit, which is disposed on the left and right sides of the display area 10 and is respectively connected to each row of luminous sub-pixels to implement row-by-row scanning of luminous sub-pixels.

[0055] Figure 4 FIG. 1 shows a driving architecture of a full-screen fingerprint sensing panel in another embodiment of the present invention. Figure 3 It is shown that the sensing sub-pixel 22 and the light-emitting sub-pixel are driven by two different ICs, namely a fingerprint sensing chip 40 (Fingerprint Sensor IC) and a panel driver chip 62 (Display Driver IC). Figure 4 In the illustrated embodiment, the sensing sub-pixel 22 and the emitting sub-pixel (ie, RGB sub-pixel) can be driven by the same IC 50 (FDI, fingerprint sensor IC+DisplayDriver IC), so that the same IC pin can be used to provide the fingerprint recognition output voltage and the display input voltage. Figure 4 and Figure 3 The same reference numerals denote the same components and their description will not be repeated here.

[0056] Furthermore, an embodiment of the present invention also provides a display device, wherein the display device is configured as follows Figures 1 to 4 Full-screen fingerprint sensing panel described in any embodiment. The features and principles of the full-screen fingerprint sensing panel described in any of the above embodiments can be applied to the display device embodiment, and the features and principles of the full-screen fingerprint sensing panel that have been explained will not be repeated.

[0057] The display device of this embodiment performs grouping operations on the output signals of the full-screen sensing sub-pixels 22 by columns through the adder 30, thereby reducing the difference between the output signals of the sensing sub-pixels 22 caused by the electrical instability of the device, reducing the misjudgment rate of the fingerprint sensing signal by the fingerprint sensing chip 40, and improving the fingerprint recognition accuracy of the full-screen fingerprint sensing panel.

[0058] In summary, the full-screen fingerprint sensing panel and display device of the present invention, by performing group operations on the output signals of the full-screen sensing sub-pixels 22 through the adder 30, can overcome the increase in the change in the current output between the sensing sub-pixels 22 caused by the electrical instability of the device (mainly referring to the instability of the threshold voltage of the driving transistor of the sensing sub-pixel 22), eliminate the difference between the output signals of each sensing sub-pixel 22 caused by the uneven threshold voltage of the driving transistor of each sensing sub-pixel 22, and enable the fingerprint sensing chip 40 to perform fingerprint recognition based on the output signal after the group operation of the adder 30, which can reduce the misjudgment rate of the fingerprint sensing signal by the fingerprint sensing chip 40 and improve the fingerprint recognition accuracy of the full-screen fingerprint sensing panel.

[0059] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A full-screen fingerprint sensing panel, characterized in that: include: Pixel units distributed throughout the display area, each of the pixel units comprising a sensing sub-pixel; The fingerprint sensing chip connects each column of sensing sub-pixels through sensing data lines; An adder is connected between the sensing sub-pixels and the fingerprint sensing chip, and the adder performs group operations on the output signals of the sensing sub-pixels in each column and transmits the output signals to the fingerprint sensing chip.

2. The full-screen fingerprint sensing panel according to claim 1, characterized in that: The adder performs group operations on the output signals of the sensing sub-pixels in each column, so that the number of columns of each group of sensing sub-pixels is continuous, the number of columns of each group of sensing sub-pixels is the same, and the operation method of the output signals of each group of sensing sub-pixels is the same.

3. The full-screen fingerprint sensing panel as claimed in claim 2, characterized in that: The operation mode includes one or more of addition, subtraction, multiplication and division.

4. The full-screen fingerprint sensing panel according to claim 1, wherein: The sensing circuit of each sensing sub-pixel comprises: A first switch transistor and a storage capacitor connected in series between the first voltage signal and the second voltage signal; A driving transistor and a second switching transistor connected in series between the first voltage signal and the output terminal; A photodiode, wherein a first electrode of the photodiode receives a voltage signal, and a second electrode of the photodiode is connected to a gate of the driving transistor via a series node of the first switching transistor and the storage capacitor; The gate of the first switch transistor receives a reset signal, and the gate of the second switch transistor receives a row selection signal.

5. The full-screen fingerprint sensing panel as claimed in claim 4, characterized in that: The photodiode is reverse biased, an anode of the photodiode receives the second voltage signal, and a cathode of the photodiode is connected to the series node.

6. The full-screen fingerprint sensing panel as claimed in claim 4, characterized in that: The reset signal and the row selection signal come from a sensing pixel scanning circuit. The sensing pixel scanning circuit is connected to sensing sub-pixels in each row through sensing scanning lines. The sensing pixel scanning circuit is arranged at both sides of the display area.

7. The full-screen fingerprint sensing panel according to claim 1, wherein: Each of the pixel units also includes a light-emitting sub-pixel; The full-screen fingerprint sensing panel also includes a panel driving chip, and the panel driving chip is connected to each column of light-emitting sub-pixels through pixel data lines.

8. The full-screen fingerprint sensing panel according to claim 7, wherein: Also includes: A multiplexing circuit, wherein the sensing data line derived from the sensing sub-pixel is connected to the fingerprint sensing chip via the adder, and the pixel data line derived from the light-emitting sub-pixel is connected to the panel driving chip via the multiplexing circuit.

9. The full-screen fingerprint sensing panel according to claim 7, wherein: Also includes: The light-emitting pixel scanning circuit is connected to each row of light-emitting sub-pixels through pixel scanning lines, and the light-emitting pixel scanning circuit is arranged on both sides of the display area.

10. A display device, characterized in that: The display device is configured with a full-screen fingerprint sensing panel as described in any one of claims 1-9.

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