Fingerprint sensor and display device including the fingerprint sensor

Abstract

A fingerprint sensor and a display device including the fingerprint sensor are provided. The fingerprint sensor includes: a light-receiving element; a first transistor connected to a second node and a third node based on a voltage of a first node serving as a first electrode of the light-receiving element; a second transistor connected to the second node and a lead based on a scan signal; a third transistor supplying a reset voltage to the first node based on a first reset signal; and a fourth transistor connected to the first node and the second node based on a second reset signal.

Description

Technical Field

[0001] The present invention relates to a fingerprint sensor and a display device including the fingerprint sensor. Background Technology

[0002] With the development of the information society, the requirements for display devices used to display images are increasing in various forms. For example, display devices are suitable for a variety of electronic devices such as smartphones, digital cameras, laptops, navigation devices, and smart TVs. Display devices can be flat panel display devices such as liquid crystal display devices, field emission display devices, and organic light-emitting display devices.

[0003] Display devices may include display panels for displaying images, light sensors for sensing light, fingerprint sensors for sensing human fingerprints, and so on. As display devices are adapted for various electronic devices, there is a need for display devices with diverse designs. For example, removing sensor devices such as separate light sensors or fingerprint sensors from the display device can expand the display area for displaying images. Summary of the Invention

[0004] The problem to be solved by the present invention is to provide a fingerprint sensor that compensates for the threshold voltage characteristics of the transistors of each of a plurality of fingerprint sensors, thereby improving sensitivity, and a display device including the fingerprint sensor.

[0005] The subject matter of this invention is not limited to the subject matter mentioned above, and other technical subject matter not mentioned can be clearly understood by those skilled in the art through the following.

[0006] A fingerprint sensor according to an embodiment for solving the above-mentioned problems includes: a light-receiving element; a first transistor connected to a second node and a third node based on a voltage of a first node serving as a first electrode of the light-receiving element; a second transistor connected to the second node and a lead based on a scan signal; a third transistor supplying a reset voltage to the first node based on a first reset signal; and a fourth transistor connected to the first node and the second node based on a second reset signal.

[0007] The first electrode of the light-receiving element can be connected to the gate electrode of the first transistor, and the second electrode of the light-receiving element can receive a bias voltage.

[0008] The fingerprint sensor may further include: a fifth transistor that supplies a common voltage to the third node based on the scan signal; and a sixth transistor that supplies a sampling voltage to the third node based on the second reset signal.

[0009] The third transistor can be turned on during a first time period to supply the reset voltage to the first node.

[0010] The fourth transistor can be turned on in a second time period after the first time period to connect the first node and the second node.

[0011] The sixth transistor can be turned on in a second time period after the first time period to supply the sampling voltage to the third node.

[0012] The light-receiving element can receive reflected light during a third time period after the second time period, causing the current to flow out of the first node.

[0013] The fifth transistor can supply the common voltage to the third node during a fourth time period following the third time period.

[0014] The first transistor can supply output current to the second node based on the voltage of the first node during a fourth time period following the third time period.

[0015] The second transistor can connect the second node to the lead during a fourth time period following the third time period.

[0016] A display device according to an embodiment for solving the above-mentioned problems includes: a display layer for displaying an image; a fingerprint sensor layer disposed on one side of the display layer and equipped with a plurality of fingerprint sensors that receive reflected light to generate a sensing signal; and a sensor driving unit that receives the sensing signal through a lead connected to each of the plurality of fingerprint sensors, wherein each of the plurality of fingerprint sensors includes: a light-receiving element; a first transistor that connects a second node and a third node based on a voltage of a first node serving as a first electrode of the light-receiving element; a second transistor that connects the second node and the lead based on a scan signal; a third transistor that supplies a reset voltage to the first node based on a first reset signal; and a fourth transistor that connects the first node and the second node based on a second reset signal.

[0017] Each of the plurality of fingerprint sensors may further include: a fifth transistor that supplies a common voltage to the third node based on the scan signal; and a sixth transistor that supplies a sampling voltage to the third node based on the second reset signal.

[0018] The third transistor can be turned on during a first time period to supply the reset voltage to the first node.

[0019] The fourth transistor can be turned on in a second time period after the first time period to connect the first node and the second node, and the sixth transistor can be turned on in the second time period to supply the sampling voltage to the third node.

[0020] The first electrode of the light-receiving element can be connected to the gate electrode of the first transistor, the second electrode of the light-receiving element can receive a bias voltage, and the light-receiving element can receive the reflected light during a third time period after the second time period, so that current flows from the first electrode to the second electrode.

[0021] The fifth transistor can supply the common voltage to the third node during a fourth time period after the third time period, the first transistor can supply the output current to the second node based on the voltage of the first node during the fourth time period, and the second transistor can connect the second node to the lead during the fourth time period.

[0022] The display device may further include an optical system disposed between the display layer and the fingerprint sensor layer, and equipped with a plurality of holes.

[0023] The first electrode of the light-receiving element can be arranged on the base component of the fingerprint sensor layer and connected to the first electrode of the third transistor or the first electrode of the fourth transistor.

[0024] The light-receiving element may include: a light-receiving layer disposed on one side of the first electrode of the light-receiving element; and a second electrode disposed on one side of the light-receiving layer to receive a bias voltage.

[0025] The second electrode may include a transparent conductive material.

[0026] Specific details of other embodiments are provided in the detailed description and accompanying drawings.

[0027] The fingerprint sensor and display device including the fingerprint sensor according to the embodiment include a first transistor to a sixth transistor and a light-receiving element, thereby compensating for the threshold voltage characteristics of the first transistor in each of the plurality of fingerprint sensors. Therefore, the display device can maintain a constant voltage at the gate electrode of the first transistor connected to the light-receiving element, thereby compensating for the dispersion of the first transistors in each of the plurality of fingerprint sensors and improving the sensitivity of the fingerprint sensor.

[0028] The effects of the embodiments are not limited to those illustrated above, and more diverse effects are included in this specification. Attached Figure Description

[0029] Figure 1 This is a perspective view of a display device according to one embodiment.

[0030] Figure 2 This is an exploded perspective view of a display device according to one embodiment.

[0031] Figure 3 This is a plan view of the display panel of a display device according to one embodiment.

[0032] Figure 4 This is a cross-sectional view of a display device according to an embodiment.

[0033] Figure 5 This is a diagram illustrating the connection relationship between pixels and lines in a display device according to one embodiment.

[0034] Figure 6 This is a diagram illustrating the connection relationship between the fingerprint sensor and the wire in a display device according to an embodiment.

[0035] Figure 7 This is a circuit diagram showing a fingerprint sensor of a display device according to an embodiment.

[0036] Figure 8 It is the supply to Figure 7 The waveform of the fingerprint sensor signal.

[0037] Figure 9 This is a diagram illustrating the driving of a fingerprint sensor during a first time period in a display device according to an embodiment.

[0038] Figure 10 This is a diagram illustrating the driving of a fingerprint sensor during a second time period in a display device according to an embodiment.

[0039] Figure 11 This is a diagram illustrating the driving of a fingerprint sensor during a third time period in a display device according to an embodiment.

[0040] Figure 12 This is a diagram illustrating the driving of a fingerprint sensor during a fourth time period in a display device according to an embodiment.

[0041] Figure 13 This is a perspective view showing the path of reflected light in a display device according to an embodiment.

[0042] Figure 14 This is a diagram illustrating the fingerprint pixels and sensor pixels of a display device according to an embodiment.

[0043] Figure 15 This is a plan view illustrating the optical system of a display device according to an embodiment.

[0044] Figure 16 This is a cross-sectional view showing the path of reflected light in a display device according to one embodiment.

[0045] Explanation of reference numerals in the attached figures:

[0046] 10: Display device 100: Cover window

[0047] 300: Display panel; DPL: Display layer

[0048] TFTL: Thin Film Transistor Layer; EML: Light Emitting Element Layer

[0049] TFEL1: First thin-film encapsulation layer; TSL: Touch sensor layer

[0050] SUB1: First substrate PHL: Optical system

[0051] SUB2: Second substrate FPSL: Fingerprint sensor layer

[0052] SUB3: Third substrate BF: Buffer layer

[0053] PDL: Photoreceiving element layer; TFEL2: Second thin-film encapsulation layer

[0054] 410: Display driver unit; 420: Circuit board

[0055] 430: Sensor driver unit; 440: Touch driver unit

[0056] 450: Gate driving section; 460: Scan driving section

[0057] 310: Thin-film transistor; 330: Light-emitting element

[0058] 340: Pixel definition film; 350: Switching transistor

[0059] PD: Light-receiving element; ST1: First transistor

[0060] ST2: Second transistor; ST3: Third transistor

[0061] ST4: Fourth transistor; ST5: Fifth transistor

[0062] ST6: Sixth Transistor Detailed Implementation

[0063] References and Appendix Figure 1The advantages and features of the invention, as well as the methods for achieving them, will become clear from the detailed embodiments described below. However, the invention can take many different forms and is not limited to the embodiments disclosed below. These embodiments are provided only to complete the disclosure of the invention and to fully inform those skilled in the art of the invention of its scope, which is defined only by the scope of the claims.

[0064] The reference to elements or layers being "on" other elements or layers includes situations where they are immediately above or adjacent to other elements, or where other layers or elements are sandwiched in between. Throughout this specification, the same reference numerals refer to the same constituent elements. The shapes, dimensions, ratios, angles, quantities, etc., disclosed in the drawings used to illustrate embodiments are exemplary, and therefore the invention is not limited to the matters illustrated.

[0065] Although terms such as "first" and "second" are used to describe multiple constituent elements, these constituent elements are clearly not limited to these terms. These terms are only used to distinguish one constituent element from another. Therefore, the "first constituent element" mentioned below can obviously also be a "second constituent element" within the technical concept of this invention.

[0066] The various features of the multiple embodiments of the present invention can be partially or wholly combined or integrated with each other, and can be linked and driven in various ways in terms of technology. Each embodiment can be implemented independently of each other, or can be implemented together in a related relationship.

[0067] The specific embodiments will now be described with reference to the accompanying drawings.

[0068] Figure 1 This is a perspective view of a display device according to one embodiment. Figure 2 This is an exploded perspective view of a display device according to one embodiment.

[0069] Reference Figure 1 and Figure 2 The display device 10 includes a cover window 100, a display panel 300, a bracket 600, a main circuit board 700, and a lower cover 900.

[0070] In this specification, "upper," "top," and "above" refer to the upper direction relative to the display device 10, i.e., the Z-axis direction. "Lower," "bottom," and "below" refer to the lower direction relative to the display device 10, i.e., the opposite direction of the Z-axis direction. Furthermore, "left," "right," "up," and "down" refer to the direction when the display device 10 is viewed from a flat surface. For example, "left" refers to the opposite direction of the X-axis direction, "right" refers to the X-axis direction, "up" refers to the Y-axis direction, and "down" refers to the opposite direction of the Y-axis direction.

[0071] As a device for displaying video or still images, the display device 10 can be used not only for the display screens of portable electronic devices such as mobile phones, smartphones, tablet personal computers (PCs), smartwatches, watch phones, mobile communication terminals, electronic notebooks, e-books, portable multimedia players (PMPs), navigators, and ultra-mobile PCs (UMPCs), but also for the display screens of various products such as televisions, laptops, monitors, billboards, and the Internet of Things (IoT).

[0072] The display device 10 can be configured in a rectangular shape on a plane. For example, the display device 10 is as follows: Figure 1 and Figure 2 The planar shape shown can be a rectangle with a short side in a first direction (X-axis direction) and a long side in a second direction (Y-axis direction). The corner where the short side in the first direction (X-axis direction) meets the long side in the second direction (Y-axis direction) can be smoothly formed with a predetermined curvature, or it can be formed as a right angle. The planar shape of the display device 10 is not limited to a rectangle, and can be formed as other polygons, circles, or ellipses.

[0073] Cover window 100 can be arranged on the upper part of display panel 300 to cover the upper surface of display panel 300. Cover window 100 can protect the upper surface of display panel 300.

[0074] The cover window 100 may include a transmissive area TA corresponding to the display area DA of the display panel 300 and a non-transmissive area NTA corresponding to the non-display area NDA of the display panel 300. For example, the non-transmissive area NTA may be formed to be opaque. As another example, when the non-transmissive area NTA does not display an image, it may be formed with a decorative layer having a pattern that allows the user to see it.

[0075] The display panel 300 can be arranged below the cover window 100. Therefore, the image displayed by the display panel 300 can be recognized on the upper surface of the display device 10 through the cover window 100.

[0076] Display panel 300 can be a light-emitting display panel that includes a light-emitting element. For example, display panel 300 can be an organic light-emitting display panel that uses an organic light-emitting diode (OLED) including an organic light-emitting layer, an ultra-small light-emitting diode (Micro LED) display panel that uses a micro LED, a quantum dot light-emitting display panel that uses a quantum dot light-emitting diode (Quantumdot LED) including a quantum dot light-emitting layer, or an inorganic light-emitting display panel that uses an inorganic light-emitting element that includes an inorganic semiconductor. Hereinafter, the case where display panel 300 is an organic light-emitting display panel will be described in detail.

[0077] The display panel 300 may include a display area DA and a non-display area NDA.

[0078] The display area DA can be arranged to overlap with the transmissive area TA of the overlay window 100. The display area DA may include multiple pixels displaying an image, and the non-display area NDA, as the peripheral area of ​​the display area DA, may not display an image. For example, the non-display area NDA may surround the display area DA, but is not limited to this. The display area DA may occupy a large portion of the display panel 300.

[0079] For example, the display panel 300 may include a touch electrode layer capable of sensing objects such as a human finger or a pen. The touch electrode layer may include multiple touch electrodes and may be arranged on a display layer on which multiple pixels are arranged.

[0080] The display panel 300 may include a display driver unit 410, a circuit board 420, a sensor driver unit 430, and a touch driver unit 440.

[0081] The display driver unit 410 can output signals and voltages for driving the display panel 300. For example, the display driver unit 410 can supply data voltage to the data lines. The display driver unit 410 can supply driving voltage or power supply voltage to the driving voltage lines, and can supply gate control signals to the gate driver unit.

[0082] The circuit board 420 can be attached to the pad using an anisotropic conductive film (ACF). The leads of the circuit board 420 can be electrically connected to the pad of the display panel 300. For example, the circuit board 420 can be a flexible printed circuit board (FPCB), a rigid printed circuit board (RPCB), or a flexible film such as a chip-on-film (COF).

[0083] The sensor driver unit 430 can be disposed on the circuit board 420 and electrically connected to the fingerprint sensor built into the display panel 300 or a separate fingerprint sensor attached to the display panel 300. The sensor driver unit 430 can convert the voltage sensed by the light-receiving element on the display panel 300 or the light-receiving element attached to the display panel 300 into sensing data as digital data and transmit it to the main processor 710.

[0084] The touch driver unit 440 can be disposed on the circuit board 420 to measure the capacitance of the touch electrodes. For example, the touch driver unit 440 can determine whether a user has touched the device and the location of the touch based on changes in the capacitance of the touch electrodes. Here, a user touch means that an object such as a user's finger or a pen directly contacts a surface of the display device 10 disposed on the touch electrode layer. The touch driver unit 440 can distinguish between the portions of the multiple touch electrodes where a user touch has occurred and the portions where no user touch has occurred to determine the location of the user touch.

[0085] The bracket 600 can be disposed at the lower part of the display panel 300. The bracket 600 can be constructed using plastic, metal, or a combination thereof. For example, the bracket 600 may include: a first camera hole CMH1 for inserting a first camera sensor 720; a battery hole BH for accommodating a battery; and a cable hole CAH for passing through a cable 415 connected to the display driver unit 410 or the circuit board 420.

[0086] The main circuit board 700 and the battery 790 can be arranged at the lower part of the bracket 600. The main circuit board 700 can be a rigid printed circuit board or a flexible printed circuit board.

[0087] The main circuit board 700 may include a main processor 710, a first camera sensor 720, and a main connector 730. The first camera sensor 720 may be disposed on the upper and lower surfaces of the main circuit board 700, the main processor 710 may be disposed on the upper surface of the main circuit board 700, and the main connector 730 may be disposed on the lower surface of the main circuit board 700.

[0088] The main processor 710 can control all functions of the display device 10. For example, the main processor 710 can supply digital video data to the display driver 410 to display images on the display panel 300. The main processor 710 can receive sensing data from the sensor driver 430 to generate a fingerprint image and can recognize the pattern of the user's fingerprint. The main processor 710 can perform authentication or applications based on the user's fingerprint. After receiving touch data from the touch driver 440 and determining the user's touch coordinates, the main processor 710 can execute the application indicated by the icon displayed at the user's touch coordinates.

[0089] The main processor 710 can convert the first image data input from the first camera sensor 720 into digital video data and output it to the display driver unit 410 through the circuit board 420, so that the image captured by the first camera sensor 720 can be displayed on the display panel 300.

[0090] The first camera sensor 720 can process image frames such as still images or videos obtained by the image sensor and output them to the main processor 710. For example, the first camera sensor 720 can be a CMOS image sensor or a CCD sensor, but is not limited to these. The first camera sensor 720 can be exposed on the lower surface of the lower cover 900 through the second camera hole CMH2, and can capture images of objects or backgrounds arranged at the bottom of the display device 10.

[0091] The main connector 730 can be connected to the cable 415 passing through the cable hole CAH of the bracket 600. Accordingly, the main circuit board 700 can be electrically connected to the display driver unit 410 or the circuit board 420.

[0092] The battery 790 can be arranged so that it does not overlap with the main circuit board 700 in the third direction (Z-axis direction). The battery 790 can overlap with the battery hole BH of the bracket 600.

[0093] The main circuit board 700 may also include a mobile communication module capable of transmitting / receiving wireless signals to at least one of a base station, external terminal, or server on a mobile communication network. The wireless signals may include data in various forms, such as voice signals, video call signals, or text / multimedia messages, for transmission / reception.

[0094] The lower cover 900 can be disposed below the main circuit board 700 and the battery 790. The lower cover 900 can be fixed to the bracket 600. The lower cover 900 can form the appearance of the lower surface of the display device 10. The lower cover 900 can be constructed using plastic, metal, or a combination thereof.

[0095] The lower cover 900 may include a second camera aperture CMH2 that exposes the lower surface of the first camera sensor 720. The location of the first camera sensor 720 and the locations of the first camera aperture CMH1 and the second camera aperture CMH2 corresponding to the first camera sensor 720 are not limited to... Figure 2 The illustrated embodiment.

[0096] Figure 3 This is a plan view of the display panel of a display device according to one embodiment.

[0097] Reference Figure 3 The display panel 300 may include a display area DA and a non-display area NDA.

[0098] The display area DA, as the area for displaying an image, may include multiple pixels SP. Furthermore, the display area DA can be used as a detection component for detecting the external environment. For example, the display area DA can be equivalent to a fingerprint recognition area for a user's fingerprint. The display layer of the display panel 300 may include multiple pixels SP, and the fingerprint sensor layer of the display panel 300 may include multiple fingerprint sensors FPS, and the multiple pixels SP and the multiple fingerprint sensors FPS can overlap in the display area DA along a third direction (Z-axis). Therefore, while displaying an image, the display area DA can also be used as an area for recognizing a user's fingerprint. For example, the display layer of the display panel 300 with multiple pixels SP and the fingerprint sensor layer of the display panel 300 with multiple fingerprint sensors FPS can overlap in a third direction (Z-axis).

[0099] The non-display area NDA can be defined as the remaining area in the display panel 300 other than the display area DA. For example, the non-display area NDA may include: a gate driving section for applying gate signals to gate lines; a fan-out line connecting data lines and the display driving section; and a pad for connection to the circuit board. For example, the non-display area NDA may be formed as an opaque area. The non-display area NDA may be formed as a decorative layer with a pattern visible to the user.

[0100] The display panel 300 may also include a sub-region SBA that protrudes from one side of the non-display area NDA.

[0101] The sub-region SBA can protrude from one side of the non-display area NDA in the opposite direction of the second direction (Y-axis direction). For example, the length of the sub-region SBA in the first direction (X-axis direction) can be less than the length of the display area DA in the first direction (X-axis direction), and the length of the sub-region SBA in the second direction (Y-axis direction) can be less than the length of the display area DA in the second direction (Y-axis direction), but it is not limited thereto. The sub-region SBA can be curved and can be arranged at the lower part of the display panel 300. In this case, the sub-region SBA can overlap with the display area DA in the third direction (Z-axis direction).

[0102] The display driver unit 410 and the circuit board 420 can be arranged on the sub-region SBA of the display panel 300. The circuit board 420 can be attached to the pad of the sub-region SBA of the display panel 300 using a low-resistance, high-reliability material such as anisotropic conductive film or self-assembly anisotropic conductive paste (SAP).

[0103] Figure 4 This is a cross-sectional view of a display device according to an embodiment.

[0104] Reference Figure 4 The display panel 300 may include a first substrate SUB1, an optical system PHL, a display layer DPL, and a fingerprint sensor layer FPSL.

[0105] The first substrate SUB1 can be a base substrate or base component of the display layer DPL, and can be constructed using an insulating material such as a polymer resin. For example, the first substrate SUB1 can be constructed using polyethersulfone (PES), polyacrylate (PAC), polyarylate (PAR), polyetherimide (PEI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyimide (PI), polycarbonate (PC), cellulose triacetate (CTA), cellulose acetate propionate (CAP), or a combination thereof.

[0106] For example, the first substrate SUB1 can be a rigid substrate. As another example, the first substrate SUB1 can be a flexible substrate capable of bending, folding, rolling, etc. When the first substrate SUB1 is a flexible substrate, it can be formed using polyimide (PI), but it is not limited to this.

[0107] As another example, the first substrate SUB1 can be omitted, and the upper surface of the fingerprint sensor layer FPSL can be directly attached to the lower surface of the optical system PHL by means of the adhesive component OCA.

[0108] The optical system PHL can be disposed on the lower surface of the display layer DPL. The optical system PHL can be disposed between the first substrate SUB1 and the thin film transistor layer TFTL to block light incident on the thin film transistor layer TFTL and the light-emitting element layer EML.

[0109] For example, the optical system PHL can be formed as a single layer or multiple layers made of any one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or alloys thereof. As another example, the optical system PHL can be configured as a black matrix, and can also be constructed using various materials with light-blocking properties.

[0110] The optical system PHL may include multiple apertures H. These apertures H can serve as optical channels for a first light L1 emitted from the light-emitting element layer EML, which is reflected by the user's body and travels towards the fingerprint sensor layer FPSL. For example, each of the multiple apertures H can correspond to the space surrounded by the first substrate SUB1, the inner wall of the aperture H of the optical system PHL, and the second substrate SUB2. Alternatively, the multiple apertures H can be filled by the material constituting the second substrate SUB2 during its formation on the optical system PHL. In this case, the multiple apertures H can also serve as optical channels for the second light L2 emitted from the light-emitting element layer EML, which is reflected by the user's body and travels towards the fingerprint sensor layer FPSL.

[0111] The multiple apertures H may not overlap with the multiple thin-film transistors of the thin-film transistor layer (TFTL), while the optical system PHL may overlap with the multiple thin-film transistors of the TFTL. For example, the multiple apertures H may be arranged along a first direction (X-axis direction) and a second direction (Y-axis direction). The size of each of the multiple apertures H may be determined based on the path of the second light L2.

[0112] The display layer DPL may include a second substrate SUB2, a thin film transistor layer TFTL, a light-emitting element layer EML, a first thin film encapsulation layer TFEL1, and a touch sensor layer TSL.

[0113] The second substrate SUB2 can be disposed on top of the optical system PHL to support the thin-film transistor layer (TFTL). For example, the second substrate SUB2 can be made of an insulating material such as a polymer resin.

[0114] For example, the second substrate SUB2 can be a rigid substrate. As another example, the second substrate SUB2 can be a flexible substrate capable of bending, folding, rolling, etc. When the second substrate SUB2 is a flexible substrate, it can be formed using polyimide (PI), but it is not limited to this.

[0115] In another example, the second substrate SUB2 can be omitted, and the thin-film transistor layer TFTL can be directly disposed on the optical system PHL.

[0116] A thin-film transistor layer (TFTL) may be disposed on the upper part of the second substrate SUB2. The TFTL may include at least one thin-film transistor driving each of a plurality of pixels SP. The at least one thin-film transistor of the pixel SP may include a semiconductor layer, a gate electrode, a drain electrode, and a source electrode. For example, the TFTL may also include a gate line, a data line, a power line, a gate control line, and a routing line connecting the pad to the data line, all connected to at least one thin-film transistor of the pixel SP.

[0117] The light-emitting element layer (EML) can be disposed on top of the thin-film transistor layer (TFTL). The EML can include a light-emitting element connected to at least one thin-film transistor of the TFTL. The light-emitting element can include a first electrode, a light-emitting layer, and a second electrode. For example, the light-emitting layer can be an organic light-emitting layer formed using organic materials, but it is not limited thereto. When the light-emitting layer is equivalent to an organic light-emitting layer, if the thin-film transistor of the TFTL applies a predetermined voltage to the first electrode of the light-emitting element, and the second electrode of the light-emitting element receives a common voltage or a cathode voltage, then holes and electrons can move to the organic light-emitting layer through the hole transport layer and the electron transport layer, respectively, and the holes and electrons can combine with each other in the organic light-emitting layer to emit light.

[0118] The light-emitting element layer (EML) may include a pixel definition film that defines multiple pixels (SPs). The first electrode of the light-emitting element and the light-emitting layer may be separated from each other and insulated by the pixel definition film.

[0119] The first thin-film encapsulation layer TFEL1 can be disposed on top of the light-emitting element layer EML, covering both the thin-film transistor layer TFTL and the light-emitting element layer EML. The first thin-film encapsulation layer TFEL1 can prevent oxygen or moisture from penetrating into the light-emitting element layer EML. For example, the first thin-film encapsulation layer TFEL1 may include at least one inorganic film. The first thin-film encapsulation layer TFEL1 may include, but is not limited to, inorganic films such as silicon nitride, silicon oxynitride, silicon oxide, titanium oxide, or aluminum oxide.

[0120] The first thin-film encapsulation layer TFEL1 can protect the light-emitting element layer EML from foreign matter such as dust. For example, the first thin-film encapsulation layer TFEL1 may include at least one organic film. The first thin-film encapsulation layer TFEL1 may include, but is not limited to, organic films such as acrylic resin, epoxy resin, phenolic resin, polyamide resin, or polyimide resin.

[0121] The touch sensor layer TSL can be disposed on the top of the first thin film encapsulation layer TFEL1. The touch sensor layer TSL can be disposed directly on the top of the first thin film encapsulation layer TFEL1, thereby reducing the thickness of the display device 10 compared to the case where a separate touch panel including the touch sensor layer TSL is attached to the first thin film encapsulation layer TFEL1.

[0122] The touch sensor layer (TSL) may include touch electrodes for sensing user touches and touch electrode lines connecting the pad and the touch electrodes. The touch electrodes of the touch sensor layer (TSL) may be arranged in a touch sensing area that overlaps with the display area (DA) of the display panel 300.

[0123] Cover window 100 can be arranged on the upper part of display panel 300. Cover window 100 can be arranged on the upper part of touch sensor layer TSL of display panel 300. For example, cover window 100 can be attached to touch sensor layer TSL by means of transparent adhesive component. Cover window 100 can directly contact user's finger F.

[0124] The fingerprint sensor layer FPSL can be disposed on the lower part of the first substrate SUB1. For example, the fingerprint sensor layer FPSL can be attached to the lower part of the first substrate SUB1 by means of an adhesive component OCA. For example, the adhesive component OCA can be an optical clear adhesive component, but is not limited to this. The upper surface of the first substrate SUB1 can face the optical system PHL, and the lower surface of the first substrate SUB1 can face the fingerprint sensor layer FPSL.

[0125] The fingerprint sensor layer FPSL can include Figure 3 The diagram shows multiple fingerprint sensor FPSs, which can be connected to the sensor driver unit 430. The multiple fingerprint sensor FPSs can be optical fingerprint sensors. For example, the multiple fingerprint sensor FPSs can be constructed using a photodiode, a CMOS image sensor, a CCD camera, a phototransistor, etc., but are not limited to these. The multiple fingerprint sensor FPSs can identify fingerprints by sensing light reflected from the ridges FR and valleys FV between the ridges FR of the finger F.

[0126] For example, if a user's finger F touches the cover window 100, the first light L1 emitted from the light-emitting element layer EML can be reflected by the ridge FR or valley FV of the finger F, and the reflected second light L2 can pass through the aperture H of the optical system PHL to reach the fingerprint sensor layer FPSL disposed on the lower part of the first substrate SUB1. The sensor driving unit 430 can distinguish between the second light L2 reflected from the ridge FR of the finger F and the second light L2 reflected from the valley FV of the finger F, which are received by the fingerprint sensor FPS, to generate sensing data, and can transmit the sensing data to the main processor 710. The main processor 710 can generate a fingerprint image based on the sensing data, thereby recognizing the pattern of the user's fingerprint. Therefore, the multiple apertures H of the optical system PHL can become channels for the second light L2 reflected by the user's finger F.

[0127] For the display device 10, the process can be simplified by placing the fingerprint sensor layer FPSL at the bottom of the display panel 300, and since the fingerprint sensor FPS is not placed on the path of the first light L1 output (e.g., above the light-emitting element layer EML), resolution reduction can be prevented.

[0128] The fingerprint sensor layer FPSL may include a third substrate SUB3, a buffer layer BF, a light-receiving element layer PDL, and a second thin-film encapsulation layer TFEL2.

[0129] The third substrate SUB3 can be the base substrate or basic component of the fingerprint sensor layer FPSL, and can be constructed using an insulating material such as a polymer resin. For example, the third substrate SUB3 can be a rigid substrate. As another example, the third substrate SUB3 can be a flexible substrate capable of bending, folding, rolling, etc. In the case that the third substrate SUB3 is a flexible substrate, it can be formed using polyimide (PI), but it is not limited to this.

[0130] The buffer layer BF can be disposed on the third substrate SUB3. The buffer layer BF can be formed using an inorganic film capable of preventing the penetration of air or moisture. For example, the buffer layer BF may include multiple inorganic films stacked alternately. The buffer layer BF can be constructed using a multilayer film consisting of at least one inorganic film selected from silicon nitride, silicon oxynitride, silicon oxide, titanium oxide, or aluminum oxide layers stacked alternately, but is not limited thereto.

[0131] The photodetector layer (PDL) can be disposed on the buffer layer (BF). The PDL may include at least one thin-film transistor driving each of a plurality of fingerprint sensor (FPS) and a photodetector connected to the at least one thin-film transistor. The at least one thin-film transistor of the fingerprint sensor (FPS) may include a semiconductor layer, a gate electrode, a source electrode, and a drain electrode. For example, the PDL may also include scan lines, lead lines, and voltage lines connected to at least one thin-film transistor of the fingerprint sensor (FPS).

[0132] The light-receiving element may include a first electrode, a light-receiving layer, and a second electrode. For example, the light-receiving layer may include amorphous silicon (a-Si), but is not limited to this. The light-receiving layer can receive a second light L2 and can convert the energy of the second light L2 into an electrical signal (current or voltage) formed between the first electrode and the second electrode.

[0133] The second thin-film encapsulation layer TFEL2 can be disposed on the photoreceiving element layer PDL. The second thin-film encapsulation layer TFEL2 can cover the upper surface of the photoreceiving element layer PDL and can prevent oxygen or moisture from penetrating into the photoreceiving element layer PDL. For example, the second thin-film encapsulation layer TFEL2 may include at least one inorganic film. The second thin-film encapsulation layer TFEL2 may include, but is not limited to, inorganic films such as silicon nitride, silicon oxynitride, silicon oxide, titanium oxide, or aluminum oxide layers.

[0134] The second thin-film encapsulation layer TFEL2 can protect the photodetector layer PDL from foreign matter such as dust. For example, the second thin-film encapsulation layer TFEL2 may include at least one organic film. The second thin-film encapsulation layer TFEL2 may include, but is not limited to, organic films such as acrylic resin, epoxy resin, phenolic resin, polyamide resin, or polyimide resin.

[0135] Optionally, the fingerprint sensor layer FPSL may also include an encapsulation substrate (not shown) disposed on the second thin-film encapsulation layer TFEL2. The encapsulation substrate may cover the second thin-film encapsulation layer TFEL2 to prevent air or moisture from penetrating into the fingerprint sensor layer FPSL. For example, the encapsulation substrate, as a light-transmitting substrate, may be a glass substrate. The encapsulation substrate may be disposed on the lower surface of the first substrate SUB1 by means of an adhesive component OCA, but is not limited thereto.

[0136] Figure 5 This is a diagram illustrating the connection relationship between pixels and lines in a display device according to one embodiment.

[0137] Reference Figure 5 The display panel 300 may include a display area DA and a non-display area NDA.

[0138] The display area DA may include multiple pixels SP, voltage supply lines VL connected to the pixels SP, gate lines GL, emitter lines EL, and data lines DL.

[0139] Each pixel SP can be connected to at least one gate line GL, at least one data line DL, at least one emitter line EL, and at least one voltage supply line VL. For example, each pixel SP can be connected to two gate lines GL, one data line DL, one emitter line EL, and one voltage supply line VL, but is not limited to this. For example, each pixel SP can also be connected to more than three gate lines GL.

[0140] Each pixel SP may include a driving transistor, at least one switching transistor, a light-emitting element, and a capacitor. The driving transistor can supply a driving current to the light-emitting element according to the data voltage applied to its gate electrode, thereby causing the light-emitting element to emit light. For example, the driving transistor and at least one switching transistor may be a thin-film transistor (TFT). The light-emitting element can emit light with a predetermined brightness according to the magnitude of the driving current of the driving transistor. For example, the light-emitting element may be an organic light-emitting diode (OLED) including a first electrode, an organic light-emitting layer, and a second electrode. The capacitor can maintain a constant data voltage applied to the gate electrode of the driving transistor.

[0141] Pixel SP can receive a driving voltage via the voltage supply line VL. Here, the driving voltage can be a high-potential voltage used to drive the light-emitting element of pixel SP.

[0142] Multiple voltage supply lines VL can be spaced apart from each other along a first direction (X-axis direction) and can extend along a second direction (Y-axis direction). For example, each of the multiple voltage supply lines VL can be arranged along a column of pixels SP arranged in the display area DA. Each of the multiple voltage supply lines VL can be connected to a pixel SP arranged in the same column and can supply a driving voltage to the pixel SP.

[0143] The gate line GL and the emitter line EL can extend along a first direction (X-axis direction) and can be spaced apart from each other along a second direction (Y-axis direction) that intersects the first direction (X-axis direction). The gate line GL and the emitter line EL can be formed side by side.

[0144] The data lines DL can be spaced apart from each other along a first direction (X-axis direction) and can extend along a second direction (Y-axis direction). The data lines DL can be arranged side by side with the voltage supply lines VL.

[0145] The non-display area NDA can be defined as the remaining area in the display panel 300 excluding the display area DA. The non-display area NDA may include: a gate driving section 450 for applying a gate signal to the gate line GL; a fan-out line FOL connecting the data line DL and the display driving section 410; and a pad DP connected to the circuit board 420. The pad DP may be arranged closer to one edge of the display panel 300 than the display driving section 410.

[0146] The display driver unit 410 can be connected to the pad DP to receive digital video data and timing signals. The display driver unit 410 can convert the digital video data into analog data voltage and supply it to the data line DL via the fan-out line FOL. For example, the display driver unit 410 can be formed as an integrated circuit (IC) and can be attached to the upper part of the first substrate SUB1 using a chip-on-glass (COG) method, a chip-on-plastic (COP) method, or an ultrasonic bonding method, but it is not limited to these methods. The display driver unit 410 can generate a gate control signal and supply it to the gate driver unit 450 via the gate control line GCL.

[0147] The gate driving unit 450 can be disposed on one side of the non-display area NDA. The gate driving unit 450 may include a plurality of thin-film transistors for generating a gate signal based on a gate control signal. The gate driving unit 450 can supply the gate signal to the pixel SP through the gate line GL, and can select the pixel SP to be supplied with data voltage.

[0148] Figure 6 This is a diagram illustrating the connection relationship between the fingerprint sensor and the wires of a display device according to one embodiment.

[0149] Reference Figure 6 The fingerprint sensor layer FPSL can include a fingerprint recognition area (FPA) and a non-fingerprint recognition area (NFPA).

[0150] The fingerprint recognition area (FPA) may include multiple fingerprint sensors (FPS), multiple scan lines (SL) connected to the fingerprint sensors (FPS), multiple lead lines (ROL), and multiple voltage lines (SVL). For example, the spacing between each of the multiple fingerprint sensors (FPS) may be 5 μm to 50 μm, and one fingerprint pixel on the overlay window 100 may correspond to 20 to 30 fingerprint sensors (FPS) of the fingerprint sensor layer (FPSL), but is not limited to this.

[0151] Each of the multiple fingerprint sensor FPSs can be connected to the scan drive unit 460 via a scan line SL and can receive a scan signal from the scan drive unit 460. The scan lines SL can extend along a first direction (X-axis direction) and can be spaced apart from each other along a second direction (Y-axis direction). The scan drive unit 460 can supply scan signals to each of the multiple fingerprint sensor FPSs to select the fingerprint sensor FPS from which changes in the sensing signal are to be detected.

[0152] Each of the multiple fingerprint sensors FPS can be connected to the fingerprint pad FP via a lead wire ROL, and the fingerprint pad FP can be connected to the sensor driver unit 430. The multiple fingerprint sensors FPS can supply sensing signals to the sensor driver unit 430 via the lead wire ROL. The lead wire ROL can be spaced apart from each other along a first direction (X-axis direction) and can extend along a second direction (Y-axis direction).

[0153] The non-fingerprint recognition area (NFPA) can be arranged outside the fingerprint recognition area (FPA). The non-fingerprint recognition area (NFPA) can be defined as the remaining area excluding the fingerprint recognition area (FPA). For example, the scan drive unit 460 can be arranged on one side of the non-fingerprint recognition area (NFPA) and can be connected to the scan line SL extending to the fingerprint recognition area (FPA).

[0154] For example, when a user's finger F touches the overlay window 100, the sensing signal of the fingerprint sensor FPS that receives the scanning signal can change. The sensing signal of the fingerprint sensor FPS that receives light reflected by the ridge FR of finger F can be different from the sensing signal of the fingerprint sensor FPS that receives light reflected by the valley FV of finger F. The sensor driving unit 430 can distinguish such differences in sensing signals to generate sensing data, and the main processor 710 can determine, based on the sensing data, whether the fingerprint pixel in the overlay window 100 corresponding to the fingerprint sensor FPS is in contact with the ridge FR of finger F or the valley FV. Therefore, the main processor 710 can recognize the pattern of the user's fingerprint based on the sensing data.

[0155] The non-fingerprint recognition area NFPA may also include a fingerprint pad FP disposed on one edge of the fingerprint sensor layer FPSL. The fingerprint pad FP may be connected to the sensor driving unit 430 to supply signals applied from an external integrated circuit to the sensor driving unit 430. For example, the display layer DPL and the fingerprint sensor layer FPSL may have the same size in a plane, but are not limited to this. As another example, the size of the fingerprint sensor layer FPSL may correspond to the size of a portion of the display layer DPL.

[0156] Figure 7 This is a circuit diagram showing a fingerprint sensor of a display device according to an embodiment.

[0157] Reference Figure 7 The fingerprint sensor FPS may include the first to sixth transistors ST1, ST2, ST3, ST4, ST5, ST6, a light-receiving element PD, and a capacitor C1.

[0158] The first transistor ST1 may include a gate electrode, a source electrode, and a drain electrode. The gate electrode of the first transistor ST1 may be connected to a first node N1, the source electrode may be connected to a third node N3, and the drain electrode may be connected to a second node N2. The first transistor ST1 can control the current between the source and drain (hereinafter referred to as the "sensing current") (Isd) based on the voltage of the first node N1, which serves as the first electrode of the photodetector PD. The sensing current (Isd) flowing through the channel of the first transistor ST1 is proportional to the square of the difference between the voltage (Vsg) between the source and gate electrodes of the first transistor ST1 and the threshold voltage Vth (Isd = k' × (Vsg - Vth)). 2 Here, k' represents a scaling factor determined based on the structure and physical characteristics of the first transistor ST1, Vsg represents the source-gate voltage of the first transistor ST1, and Vth represents the threshold voltage of the first transistor ST1.

[0159] The second transistor ST2 can be turned on by the scan signal of the scan line SL(n) to connect the second node N2, which serves as the drain electrode of the first transistor ST1, to the lead-out line ROL. The gate electrode of the second transistor ST2 can be connected to the scan line SL(n), the source electrode can be connected to the second node N2, and the drain electrode can be connected to the lead-out line ROL. The source electrode of the second transistor ST2 can be connected to the drain electrode of the first transistor ST1 and the source electrode of the fourth transistor ST4 through the second node N2.

[0160] The third transistor ST3 can be turned on by the first reset signal of the first reset line RSL(n) to supply the reset voltage VR to the first node N1. The gate electrode of the third transistor ST3 can be connected to the first reset line RSL(n), the source electrode can be connected to the reset voltage line, and the drain electrode can be connected to the first node N1. The drain electrode of the third transistor ST3 can be connected to the first electrode of the photodetector PD, the gate electrode of the first transistor ST1, and the drain electrode of the fourth transistor ST4 through the first node N1.

[0161] The fourth transistor ST4 can be turned on by the second reset signal of the second reset line RSL(n+1) to connect to the first node N1 and the second node N2. The gate electrode of the fourth transistor ST4 can be connected to the second reset line RSL(n+1), the source electrode can be connected to the second node N2, and the drain electrode can be connected to the first node N1. The source electrode of the fourth transistor ST4 can be connected to the drain electrode of the first transistor ST1 and the source electrode of the second transistor ST2 through the second node N2. The drain electrode of the fourth transistor ST4 can be connected to the first electrode of the photodetector PD, the gate electrode of the first transistor ST1, and the drain electrode of the third transistor ST3 through the first node N1.

[0162] The fifth transistor ST5 can be turned on by the scan signal of the scan line SL(n) to supply a common voltage VC to the third node N3, which is the source electrode of the first transistor ST1. For example, the common voltage VC can be equivalent to a high potential voltage. The gate electrode of the fifth transistor ST5 can be connected to the scan line SL(n), the source electrode can be connected to the common voltage line, and the drain electrode can be connected to the third node N3. The drain electrode of the fifth transistor ST5 can be connected to the source electrode of the first transistor ST1 and the drain electrode of the sixth transistor ST6 through the third node N3.

[0163] The sixth transistor ST6 can be turned on by the second reset signal of the second reset line RSL(n+1) to supply the sampling voltage VS to the third node N3, which is the source electrode of the first transistor ST1. The gate electrode of the sixth transistor ST6 can be connected to the second reset line RSL(n+1), the source electrode can be connected to the sampling voltage line, and the drain electrode can be connected to the third node N3. The drain electrode of the sixth transistor ST6 can be connected to the source electrode of the first transistor ST1 and the drain electrode of the fifth transistor ST5 through the third node N3.

[0164] The light-receiving element PD can identify the user's fingerprint pattern based on the second light L2 reflected by the user's finger F. The first electrode of the light-receiving element PD can be connected to the first node N1, which serves as the gate electrode of the first transistor ST1, and the second electrode can be connected to a bias voltage line. The second electrode of the light-receiving element PD can receive a bias voltage VB from the bias voltage line. For example, the bias voltage VB can be equivalent to a low potential voltage. A capacitor C1 can be arranged between the first and second electrodes of the light-receiving element PD to prevent excessive current from flowing within the light-receiving element PD.

[0165] For example, if there is no user contact on the cover window 100, the light-receiving element PD may not receive light. The fingerprint sensor FPS can form a reverse bias between the first and second electrodes of the light-receiving element PD. Here, reverse bias means that the voltage at the first node N1, which is the first electrode of the light-receiving element PD, is greater than the bias voltage VB applied to the second electrode of the light-receiving element PD. If the light-receiving element PD does not receive light, it can have a reverse voltage between the first and second electrodes, and it can block current between the first node N1 and the bias voltage line.

[0166] If a user's finger F touches the cover window 100, the light-receiving element PD can receive the second light L2 reflected by the ridge FR or valley FV of the finger F. The first light L1 output from the light-emitting element layer EML can be reflected by the ridge FR or valley FV of the finger F, and the reflected second light L2 can reach the light-receiving element PD of the fingerprint sensor layer FPSL. The light-receiving element PD can convert the energy of the second light L2 into an electrical signal (current or voltage) formed between the first electrode and the second electrode, and the converted electrical signal can flow from the first node N1 to the bias voltage line. For example, in the case where a reverse bias is formed between the first electrode and the second electrode of the light-receiving element PD, the reverse current can flow to the light-receiving element PD in proportion to the amount of the second light L2, and the voltage of the first node N1 can be reduced. Therefore, if the light-receiving element PD receives the second light L2, the voltage of the first node N1 can be reduced, and the magnitude of the sensing current (or, the source-drain current) of the first transistor ST1 can be reduced. The sensing current of the first transistor ST1 can be applied to the sensor drive unit 430 as a sensing signal through the second transistor ST2.

[0167] The sensor driver unit 430 can generate sensing data based on the sensing signal received from the fingerprint sensor FPS, and the main processor 710 can distinguish whether the sensing data corresponds to the ridge FR of finger F or the valley FV of finger F to identify the pattern of the user's fingerprint.

[0168] For example, the light-receiving element PD can be implemented by a phototransistor or a photodiode, but is not limited to these. The light-receiving element PD can be equivalent to a light sensor that converts light energy into electrical energy, and can utilize the photovoltaic effect where the flowing current varies with the intensity of light.

[0169] Figure 8 It is the supply to Figure 7 The waveform of the fingerprint sensor signal. Figure 9 This is a diagram illustrating the driving of a fingerprint sensor during a first time period in a display device according to an embodiment. Figure 10 This is a diagram illustrating the driving of a fingerprint sensor during a second time period in a display device according to an embodiment. Figure 11 This diagram illustrates the driving of a fingerprint sensor during a third time period in a display device according to an embodiment. Figure 12 This is a diagram illustrating the driving of a fingerprint sensor during a fourth time period in a display device according to an embodiment.

[0170] Reference Figures 8 to 12 The fingerprint sensor FPS can be connected to the first reset line RSL(n), the second reset line RSL(n+1), and the scan line SL(n). When multiple fingerprint sensor FPS are driven at a predetermined frequency, the time period of a frame can include the first time period to the fourth time period t1, t2, t3, t4.

[0171] Combination Figure 9 and Figure 8 The first reset line RSL(n) can supply a first reset signal RST(n) with a gate on level during the first time period t1. The third transistor ST3 can be turned on based on the first reset signal RST(n) during the first time period t1, and can supply a reset voltage VR to the first node N1. Therefore, the first node N1, which is the gate electrode of the first transistor ST1, can be reset using the reset voltage VR.

[0172] Combination Figure 10 and Figure 8The second reset line RSL(n+1) can supply a second reset signal RST(n+1) with a gate on level during a second time period t2 following the first time period t1. The sixth transistor ST6 can be turned on during the second time period t2 based on the second reset signal RST(n+1), and can supply a sampled voltage VS to the third node N3. Immediately after the sixth transistor ST6 is turned on, the third node N3, which is the source electrode of the first transistor ST1, can have a sampled voltage VS, and the first node N1, which is the gate electrode of the first transistor ST1, can have a reset voltage VR. For example, the sampled voltage VS can be greater than the reset voltage VR. In this case, the voltage (Vsg) between the source and gate electrodes of the first transistor ST1 (or, the voltage difference between the third node N3 and the first node N1) can become greater than the threshold voltage Vth of the first transistor ST1, and the first transistor ST1 can be turned on. Furthermore, the fourth transistor ST4 can be turned on during the second time period t2 based on the second reset signal RST(n+1), and can connect the second node N2 to the first node N1. Therefore, the first transistor ST1 can be turned on until the gate electrode of the first transistor ST1 reaches the voltage difference (VS-Vth) between the sampling voltage VS and the threshold voltage Vth. Finally, the first node N1, which is the gate electrode of the first transistor ST1, can be sampled by the sampling voltage VS.

[0173] Combination Figure 11 and Figure 8 The light-receiving element PD can receive light during the third time period t3 after the second time period t2.

[0174] For example, if there is no user contact on the cover window 100, the light-receiving element PD may not receive light. The fingerprint sensor FPS can form a reverse bias between the first and second electrodes of the light-receiving element PD. Here, reverse bias means that the voltage at the first node N1, which is the first electrode of the light-receiving element PD, is greater than the bias voltage VB applied to the second electrode of the light-receiving element PD. If the light-receiving element PD does not receive light, it can have a reverse voltage between the first and second electrodes, and it can block current between the first node N1 and the bias voltage line.

[0175] If a user's finger F touches the cover window 100, the light-receiving element PD can receive the second light L2 reflected by the ridge FR or valley FV of the finger F. The first light L1 output from the light-emitting element layer EML can be reflected by the ridge FR or valley FV of the finger F, and the reflected second light L2 can reach the light-receiving element PD of the fingerprint sensor layer FPSL. The light-receiving element PD can convert the energy of the second light L2 into an electrical signal (current or voltage) formed between the first electrode and the second electrode, and the converted electrical signal can flow from the first node N1 to the bias voltage line. For example, if a reverse bias is formed between the first electrode and the second electrode of the light-receiving element PD, the reverse current can flow to the light-receiving element PD in proportion to the amount of the second light L2, and the voltage of the first node N1 can be reduced. Therefore, if the light-receiving element PD receives the second light L2, the voltage of the first node N1 can be reduced, and the magnitude of the sensing current (or, the source-drain current) flowing in the first transistor ST1 during the fourth time period t4 can be reduced. The sensing current of the first transistor ST1 can be applied to the sensor drive unit 430 as a sensing signal through the second transistor ST2 during the fourth time period t4.

[0176] Combination Figure 12 and Figure 8 The scan line SL(n) can supply a scan signal SC(n) with a gate on level during the fourth time period t4 after the third time period t3. The fifth transistor ST5 can be turned on based on the scan signal SC(n) during the fourth time period t4, and can supply a common voltage VC to the third node N3. The first transistor ST1 can output a sensing current (or, source-drain current) based on the voltage of the first node N1. For example, when the magnitude of the reflected light incident on the light-receiving element PD is relatively small, the magnitude of the sensing current can be relatively large. When the magnitude of the reflected light incident on the light-receiving element PD is relatively large, the magnitude of the sensing current can be relatively small. The second transistor ST2 can be turned on based on the scan signal SC(n) during the fourth time period t4, and can connect the second node N2 to the lead-out line ROL. Therefore, the second transistor ST2 can supply the sensing current output from the first transistor ST1 to the lead-out line ROL. The fingerprint sensor FPS can supply the sensing signal Rx generated by the sensing current to the sensor driver 430 through the lead-out line ROL.

[0177] The sensor driver unit 430 can generate sensing data based on the sensing signal Rx received from the fingerprint sensor FPS. The main processor 710 can distinguish whether the sensing data corresponds to the ridge FR of finger F or the valley FV of finger F to identify the pattern of the user's fingerprint.

[0178] The display device includes a fingerprint sensor FPS equipped with first to sixth transistors ST1, ST2, ST3, ST4, ST5, ST6 and a light-receiving element PD, thereby compensating for the threshold voltage Vth characteristics of the first transistor ST1 in each of the multiple fingerprint sensor FPS. For example, when the magnitude of the current flowing into the first transistor ST1 is less than 1 μA during the fourth time period t4, the magnitude of the sensing current corresponding to the ridge FR of the finger F and the magnitude of the sensing current corresponding to the valley FV of the finger F can be clearly distinguished. Here, the magnitude of the current flowing into the first transistor ST1 is not limited to the above example. Therefore, the display device can maintain the voltage of the gate electrode of the first transistor ST1 connected to the light-receiving element PD at a constant level, thereby compensating for the dispersion of the first transistor ST1 in each of the multiple fingerprint sensor FPS and improving the sensitivity of the fingerprint sensor FPS.

[0179] Figure 13 This is a perspective view showing the path of reflected light in a display device according to one embodiment. Figure 14 This is a diagram illustrating the fingerprint pixels and sensor pixels of a display device according to an embodiment.

[0180] Reference Figure 13 and Figure 14 The display device 10 may include a cover window 100, a display layer DPL, an optical system PHL, and a fingerprint sensor layer FPSL.

[0181] The overlay window 100 may include a plurality of fingerprint pixels (FPPs) and a sampling region (SPR) surrounding each of the plurality of fingerprint pixels (FPPs). The fingerprint sensor layer (FPSL) may include a plurality of fingerprint sensors (FPSs) and a sensing region (SSR) formed by the plurality of fingerprint sensors and corresponding to a fingerprint pixel (FPP) and a hole (H).

[0182] One fingerprint pixel (FPP) on the overlay window 100 can correspond to at least one fingerprint sensor (FPS) of the fingerprint sensor layer (FPSL). For example, one fingerprint pixel (FPP) can correspond to 20 to 30 fingerprint sensor (FPS), but is not limited to this. The sampling region (SPR) on the overlay window 100 can correspond to the sensing region (SSR) of the fingerprint sensor layer (FPSL).

[0183] Each of the multiple fingerprint pixels (FPPs) can correspond to an aperture H of the optical system (PHL). Similarly, each of the multiple sensing regions (SSRs) can correspond to an aperture H of the optical system (PHL). For example, if a user's finger F touches the cover window 100, each of the multiple sampling regions (SPRs) can reflect a first light L1 emitted from the display panel 300, and a second light L2 reflected from each of the multiple sampling regions (SPRs) can reach the sensing region SSR of the fingerprint sensor layer (FPSL) through the aperture H of the optical system (PHL). The multiple apertures H of the optical system (PHL) can serve as channels for the second light L2 reflected by the user's finger F. Therefore, the multiple fingerprint sensors (FPS) can sense the second light L2 reflected by the ridges FR and valleys FV between the ridges FR of the finger F touching the sampling regions (SPRs) of the cover window 100.

[0184] Multiple fingerprint sensors (FPS) can sense the second light L2 reflected by the ridges (FR) or valleys (FV) of the finger F to generate sensing signals, and can supply the sensing signals to the sensor driving unit 430. The sensor driving unit 430 can distinguish the sensing signal corresponding to the ridge (FR) of the finger F and the sensing signal corresponding to the valley (FV) of the finger F. Therefore, the sensor driving unit 430 can combine the sensing signals of each of the multiple fingerprint sensors (FPS) to identify the fingerprint pattern of the finger F that has come into contact with the sampling area (SPR).

[0185] Each of the multiple sensing regions SSR may include a central region CA and a peripheral region SA. The central region CA may include at least one fingerprint sensor FPS disposed in the center of the sensing region SSR. The second light L2 reflected by the user's finger F can be concentrated to the central region CA. Therefore, the user's fingerprint information can be concentrated on at least one fingerprint sensor FPS in the central region CA.

[0186] The peripheral region SA may surround the central region CA. The peripheral region SA may include at least one fingerprint sensor FPS surrounding the central region CA. For example, a portion of the fingerprint sensor FPS in the peripheral region SA may receive reflected second light L2, while another portion of the fingerprint sensor FPS in the peripheral region SA may not receive reflected second light L2. As another example, the average magnitude of the second light L2 reaching the fingerprint sensor FPS in the peripheral region SA may be less than the average magnitude of the second light L2 reaching the fingerprint sensor FPS in the central region CA. Therefore, relatively less reflected second light L2 may reach the peripheral region SA. Although the fingerprint sensor FPS in the peripheral region SA may include the user's fingerprint information, it may include relatively less information compared to the fingerprint sensor FPS in the central region CA.

[0187] The display device 10 can adjust the ratio of fingerprint distance OD to sensor distance ID to sense light reflected by the user's finger F through the fingerprint sensor FPS. Here, fingerprint distance OD can be equivalent to the distance between the surface of the cover window 100 directly contacted by the user's finger F and the center point of the aperture H of the optical system PHL. Sensor distance ID can be equivalent to the distance between the center point of the aperture H of the optical system PHL and the fingerprint sensor FPS of the fingerprint sensor layer FPSL. For example, light reflected from one end of the fingerprint pixel FPP on the cover window 100 can reach the other end of the fingerprint sensor FPS through the center point of the aperture H. And light reflected from the other end of the fingerprint pixel FPP on the cover window 100 can reach one end of the fingerprint sensor FPS through the center point of the aperture H. Therefore, the shape of the fingerprint directly contacting the fingerprint pixel FPP and the image formed on the fingerprint sensor FPS can have a 180-degree difference. The sensor driving unit 430 can invert the image formed on the fingerprint sensor FPS to generate a fingerprint image. The display device 10 can adjust the ratio of fingerprint distance OD to sensor distance ID and adjust the arrangement and shape of the aperture H of the optical system PHL to improve the sensitivity of the fingerprint sensor FPS.

[0188] Figure 15 This is a plan view showing the light-blocking layer of a display device according to an embodiment.

[0189] Reference Figure 15 An optical system PHL may include multiple apertures H. For example, the planar shape of the multiple apertures H may be equivalent to a circle. The diameter r of each of the multiple apertures H may be from 3 μm to 20 μm, but is not limited to this.

[0190] Multiple apertures H can be arranged with a first spacing P1 along a first direction (X-axis direction). For example, the first spacing P1 can be 1.3 to 1.5 times the sensor distance ID, preferably 1.3 times the sensor distance ID. Here, the sensor distance ID can be equivalent to the distance between the center point of the aperture H of the optical system PHL and the fingerprint sensor FPS of the fingerprint sensor layer FPSL.

[0191] Multiple holes H can be arranged with a second spacing P2 along a second direction (Y-axis direction). For example, the second spacing P2 can be the same as the first spacing P1. As another example, the second spacing P2 can be different from the first spacing P1.

[0192] For example, multiple holes H can be arranged side by side along a first direction (X-axis direction) and a second direction (Y-axis direction). As another example, multiple holes H can also be arranged at a first spacing P1 and a second spacing P2, while being neatly arranged in directions other than the first direction (X-axis direction) and the second direction (Y-axis direction).

[0193] For example, the first spacing P1 or the second spacing P2 can be proportional to the thickness of the first thin-film encapsulation layer TFEL1. If the thickness of the first thin-film encapsulation layer TFEL1 increases, the fingerprint distance OD can increase, and the area of ​​the fingerprint pixel FPP and the sampling area SPR can also increase. Therefore, the first spacing P1 or the second spacing P2 of the multiple holes H can be proportional to the thickness of the first thin-film encapsulation layer TFEL1 in order to adjust the ratio of the fingerprint distance OD to the sensor distance ID.

[0194] For example, the first spacing P1 or the second spacing P2 can be proportional to the distance between the light-emitting elements in the light-emitting element layer EML or the distance between pixels SP. If the distance between the light-emitting elements increases, the distance between the second light L2 reflected by the finger F can also increase. Therefore, the first spacing P1 or the second spacing P2 is proportional to the distance between the light-emitting elements or the distance between pixels SP so that the multiple holes H can act as channels for the second light L2.

[0195] The optical system PHL may include first to fourth apertures H1, H2, H3, and H4 that are adjacent to each other. For example, each of the first to fourth apertures H1, H2, H3, and H4 of the optical system PHL can be arranged adjacent to each other, and the sensing region SSR corresponding to each of the first to fourth apertures H1, H2, H3, and H4 of the optical system PHL can also be arranged adjacent to each other. Therefore, the second light L2 reflected by the user's finger F can be concentrated through the first to fourth apertures H1, H2, H3, and H4 to reach the adjacent sensing regions SSR.

[0196] The shape of multiple holes H is not limited to Figure 15 The circular shape is shown. For example, multiple apertures H can be configured into various shapes such as ellipses and polygons. As another example, multiple apertures H can have different shapes within an optical system PHL.

[0197] Figure 16 This is a cross-sectional view showing the path of reflected light in a display device according to one embodiment.

[0198] Reference Figure 16 The display device 10 may include a first substrate SUB1, an optical system PHL, a second substrate SUB2, a thin film transistor layer TFTL, a light-emitting element layer EML, a first thin film encapsulation layer TFEL1, a touch sensor layer TSL, a cover window 100, a third substrate SUB3, a buffer layer BF, a light-receiving element layer PDL, and a second thin film encapsulation layer TFEL2.

[0199] The first substrate SUB1 can be a base substrate or basic component of the display layer DPL, and can be made of an insulating material such as a polymer resin. For example, the first substrate SUB1 can be a rigid substrate. As another example, the first substrate SUB1 can be a flexible substrate capable of bending, folding, rolling, etc. When the first substrate SUB1 is a flexible substrate, it can be formed using polyimide (PI), but it is not limited to this.

[0200] The optical system PHL can cover the lower surface of the thin-film transistor layer (TFTL). The optical system PHL can be positioned between the first substrate SUB1 and the TFTL to block light incident on the TFTL and the light-emitting element layer (EML). The optical system PHL can include multiple apertures H. These apertures H can serve as optical channels for a second light L2, which is reflected from the user's body and travels towards the fingerprint sensor layer (FPSL), after a first light L1 emitted from the EML.

[0201] The second substrate SUB2 can be disposed on top of the optical system PHL to support the thin-film transistor layer (TFTL). For example, the second substrate SUB2 can be made of an insulating material such as a polymer resin.

[0202] A thin-film transistor layer (TFTL) may be disposed on the upper part of the second substrate SUB2. The TFTL may include at least one thin-film transistor 310 driving each of a plurality of pixels SP. The TFTL may also include a gate insulating film 321, an interlayer insulating film 323, a protective layer 325, and a planarization layer 327. At least one thin-film transistor 310 may include a semiconductor layer 311, a gate electrode 312, a source electrode 313, and a drain electrode 314.

[0203] The semiconductor layer 311 may be disposed on the upper part of the second substrate SUB2. The semiconductor layer 311 may be arranged to overlap with the gate electrode 312, the source electrode 313 and the drain electrode 314. The semiconductor layer 311 may be in direct contact with the source electrode 313 and the drain electrode 314, and the gate insulating film 321 may be placed in the middle facing the gate electrode 312.

[0204] The gate electrode 312 can be disposed on the upper part of the gate insulating film 321. The gate electrode 312 can be disposed in the middle of the gate insulating film 321 and overlap with the semiconductor layer 311.

[0205] The source electrode 313 and drain electrode 314 can be arranged to be spaced apart from each other on the interlayer insulating film 323. The source electrode 313 can contact one end of the semiconductor layer 311 through contact holes provided in the gate insulating film 321 and the interlayer insulating film 323. The drain electrode 314 can contact the other end of the semiconductor layer 311 through contact holes provided in the gate insulating film 321 and the interlayer insulating film 323. The drain electrode 314 can directly contact the first electrode 331 of the light-emitting element 330 through contact holes in the protective layer 325.

[0206] The gate insulating film 321 may be disposed on the upper part of the semiconductor layer 311. For example, the gate insulating film 321 may be disposed on the upper part of the semiconductor layer 311 and the second substrate SUB2, and may insulate the semiconductor layer 311 from the gate electrode 312. The gate insulating film 321 may include a contact hole through which the source electrode 313 passes and a contact hole through which the drain electrode 314 passes.

[0207] The interlayer insulating film 323 can be disposed on the upper part of the gate electrode 312. For example, the interlayer insulating film 323 may include contact holes through which the source electrode 313 passes and contact holes through which the drain electrode 314 passes. Here, the contact holes of the interlayer insulating film 323 can be connected to the contact holes of the gate insulating film 321.

[0208] The protective layer 325 may be disposed on the upper part of the thin-film transistor 310 to protect the thin-film transistor 310. For example, the protective layer 325 may include a contact hole through which the first electrode 331 of the light-emitting element 330 passes.

[0209] The planarization layer 327 can be disposed on the upper part of the protective layer 325 to planarize the upper end of the thin-film transistor 310. For example, the planarization layer 327 may include a contact hole through which the first electrode 331 of the light-emitting element 330 passes. Here, the contact hole of the protective layer 325 and the contact hole of the planarization layer 327 can be connected to each other to allow the first electrode 331 of the light-emitting element 330 to pass through.

[0210] The light-emitting element layer (EML) can be disposed on top of the thin-film transistor layer (TFTL). The EML may include light-emitting elements (330) connected to the thin-film transistors (310) of the TFTL.

[0211] The light-emitting element 330 may include a first electrode 331, a light-emitting layer 332, and a second electrode 333.

[0212] The first electrode 331 may be disposed on the upper part of the planarization layer 327. For example, the first electrode 331 may be arranged to overlap with the opening region of the light-emitting element layer EML defined by the pixel defining film 340. Furthermore, the first electrode 331 may contact the drain electrode 314 of the thin-film transistor 310 through contact holes disposed in the planarization layer 327 and the protective layer 325. For example, the first electrode 331 may serve as the anode of the light-emitting element 330.

[0213] The light-emitting layer 332 may be disposed on the upper part of the first electrode 331. The light-emitting layer 332 may include a hole injection layer, a hole transport layer, a light-receiving layer, an electron blocking layer, an electron transport layer, an electron injection layer, etc. For example, the light-emitting layer 332 may be an organic light-emitting layer made of organic materials, but it is not limited to this. When the light-emitting layer 332 is equivalent to an organic light-emitting layer, if the thin-film transistor 310 of the thin-film transistor layer TFTL applies a predetermined voltage to the first electrode 331 of the light-emitting element 330, and the second electrode 333 of the light-emitting element 330 receives a common voltage or a cathode voltage, then holes and electrons can move to the light-emitting layer 332 through the hole transport layer and the electron transport layer, respectively, and the holes and electrons can combine with each other in the light-emitting layer 332 to emit light.

[0214] The second electrode 333 can be arranged on the upper part of the light-emitting layer 332. For example, the second electrode 333 can be implemented as an electrode shape that is common to the entire pixel SP, rather than being divided by pixel SP.

[0215] The light-emitting element layer (EML) may include a pixel definition film 340 that defines multiple pixels (SP). The first electrode 331 and light-emitting layer 332 of the light-emitting element 330 and the first electrode 331 and light-emitting layer 332 of another light-emitting element 330 may be separated from and insulated from each other by the pixel definition film 340.

[0216] The first thin-film encapsulation layer TFEL1 can be disposed on top of the light-emitting element layer EML, covering the thin-film transistor layer TFTL and the light-emitting element layer EML. The first thin-film encapsulation layer TFEL1 can prevent oxygen or moisture from penetrating into the light-emitting element layer EML.

[0217] The touch sensor layer (TSL) can be disposed on top of the first thin-film encapsulation layer (TFEL1). The touch sensor layer (TSL) may include touch electrodes for sensing user touches and touch electrode lines connecting the pad and the touch electrodes. The touch electrodes of the touch sensor layer (TSL) may be disposed in a touch sensing area that overlaps with the display area (DA) of the display panel 300.

[0218] Cover window 100 can be arranged on the upper part of display panel 300. Cover window 100 can be arranged on the upper part of touch sensor layer TSL of display panel 300. For example, cover window 100 can be attached to touch sensor layer TSL by means of transparent adhesive component. Cover window 100 can directly contact user's finger F.

[0219] The fingerprint sensor layer FPSL can be disposed on the lower part of the first substrate SUB1. The upper end of the first substrate SUB1 can face the optical system PHL, and the lower end of the first substrate SUB1 can face the fingerprint sensor layer FPSL. For example, the upper surface of the fingerprint sensor layer FPSL can be attached to the lower surface of the first substrate SUB1 by means of an adhesive component OCA.

[0220] As another example, the first substrate SUB1 can be omitted, and the upper surface of the fingerprint sensor layer FPSL can be directly attached to the lower surface of the optical system PHL by means of the adhesive component OCA.

[0221] For example, if a user's finger F touches the cover window 100, the first light L1 emitted from the light-emitting element layer EML can be reflected by the ridge FR or valley FV of the finger F, and the reflected second light L2 can reach the fingerprint sensor layer FPSL arranged on the lower part of the first substrate SUB1 through the aperture H of the optical system PHL.

[0222] The fingerprint sensor layer FPSL may include a third substrate SUB3, a buffer layer BF, a light-receiving element layer PDL, and a second thin-film encapsulation layer TFEL2.

[0223] The third substrate SUB3 can be the base substrate or basic component of the fingerprint sensor layer FPSL, and can be constructed using an insulating material such as a polymer resin. For example, the third substrate SUB3 can be a rigid substrate. As another example, the third substrate SUB3 can be a flexible substrate capable of bending, folding, rolling, etc. In the case that the third substrate SUB3 is a flexible substrate, it can be formed using polyimide (PI), but it is not limited to this.

[0224] The buffer layer BF can be disposed on the third substrate SUB3. The buffer layer BF can be constructed using an inorganic film capable of preventing the penetration of air or moisture. For example, the buffer layer BF may include multiple inorganic films stacked alternately. The buffer layer BF can be constructed using a multilayer film of at least one inorganic film selected from silicon nitride layer, silicon oxynitride layer, silicon oxide layer, titanium oxide layer and aluminum oxide layer stacked alternately, but is not limited thereto.

[0225] The light-receiving element layer PDL can be disposed on the buffer layer BF. The light-receiving element layer PDL may include at least one switching transistor 350 driving each of a plurality of fingerprint sensor FPS and a light-receiving element PD connected to the at least one switching transistor 350. The at least one switching transistor 350 may include a semiconductor layer 351, a gate electrode 352, a source electrode 353, and a drain electrode 354.

[0226] The semiconductor layer 351 can be disposed on the buffer layer BF. The semiconductor layer 351 can be disposed to overlap with the gate electrode 352, the source electrode 353 and the drain electrode 354.

[0227] The gate electrode 352 can be disposed on the first insulating film 361. The gate electrode 352 can be disposed in the middle of the first insulating film 361 and overlap with the semiconductor layer 351.

[0228] The source electrode 353 and the drain electrode 354 can be arranged to be spaced apart from each other on the third insulating film 365. The drain electrode 354 can directly contact the first electrode 371 of the photosensitive element PD through the contact holes of the first insulating film to the third insulating film 361, 363, 365.

[0229] The light-receiving element PD may include a first electrode 371, a light-receiving layer PSC, and a second electrode 375.

[0230] The first electrode 371 of the light-receiving element PD can be disposed on the second insulating film 363. The first electrode 371 can be connected to the drain electrode 354 of the switching transistor 350 through a contact hole penetrating the third insulating film 365. For example, the first electrode 371 can be formed as a single layer of molybdenum (Mo), titanium (Ti), copper (Cu), or aluminum (Al), or it can be formed using a laminated structure of aluminum and titanium (Ti / Al / Ti), a laminated structure of aluminum and ITO (ITO / Al / ITO), an APC alloy, or a laminated structure of APC alloy and ITO (ITO / APC / ITO).

[0231] A light-receiving layer PSC can be disposed on the first electrode 371. For example, the light-receiving layer PSC may include an N-type semiconductor layer 372, an I-type semiconductor layer 373, and a P-type semiconductor layer 374 stacked sequentially. When the light-receiving layer PSC is formed as a PIN structure including the N-type semiconductor layer 372, the I-type semiconductor layer 373, and the P-type semiconductor layer 374, the I-type semiconductor layer 373 can be depleted by the P-type semiconductor layer 374 and the N-type semiconductor layer 372, and an electric field can be generated inside the I-type semiconductor layer 373. Furthermore, holes and electrons generated by sunlight can drift by the electric field. Therefore, holes can be collected to the second electrode 375 through the P-type semiconductor layer 374, and electrons can be collected to the first electrode 371 through the N-type semiconductor layer 372.

[0232] The P-type semiconductor layer 374 can be disposed relatively close to the incident surface of the reflected light, and the N-type semiconductor layer 372 can be disposed relatively far from the incident surface of the reflected light. Since the drift mobility of holes is lower than that of electrons, the P-type semiconductor layer 374 is disposed close to the incident surface of the reflected light, thereby maximizing the collection efficiency of the reflected light.

[0233] The second electrode 375 of the light-receiving element PD can be disposed on the P-type semiconductor layer 374. The second electrode 375 can be connected to the first connecting electrode 381 through a contact hole penetrating the third insulating film 365. The second electrode 375 may include a transparent conductive material capable of transmitting light. For example, the second electrode 375 may include at least one of indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin-zinc oxide (ITZO), but is not limited thereto.

[0234] The first connecting electrode 381 can be disposed on the third insulating film 365. For example, the first connecting electrode 381 can be disposed on the third insulating film 365, separated from the source electrode 353 and the drain electrode 354. One end of the first connecting electrode 381 can be connected to the second electrode 375 of the photoreceiving element PD through a contact hole penetrating the third insulating film 365. The other end of the first connecting electrode 381 can be connected to the second connecting electrode 383 through a contact hole penetrating the second insulating film 363 and the third insulating film 365.

[0235] The second connection electrode 383 can be arranged to overlap with the photoreceiving element PD on the first insulating film 361. For example, the second connection electrode 383 can be arranged on the same layer as the gate electrode 352 of the switching transistor 350. The second connection electrode 383 can be insulated from the first electrode 371 of the photoreceiving element PD by placing the second insulating film 363 in between. The second connection electrode 383 can be connected to the first connection electrode 381 through a contact hole that passes through the second insulating film 363 and the third insulating film 365.

[0236] The light-receiving element layer PDL may also include a first insulating film to a third insulating film 361, 363, 365.

[0237] The first insulating film 361 can be disposed on the semiconductor layer 351. The first insulating film 361 can cover the semiconductor layer 351 and the buffer layer BF of the switching transistor 350, and can insulate the semiconductor layer 351 from the gate electrode 352.

[0238] The second insulating film 363 can be disposed on the gate electrode 352 and the second connection electrode 383 of the switching transistor 350. The second insulating film 363 can cover the gate electrode 352, the second connection electrode 383, and the first insulating film 361. The second insulating film 363 can insulate each of the source electrode 353 and the drain electrode 354 from the gate electrode 352, and can insulate the first electrode 371 of the light-receiving element PD from the second connection electrode 383.

[0239] The third insulating film 365 can be disposed on the light-receiving element PD. The third insulating film 365 can cover the light-receiving element PD and the second insulating film 363.

[0240] The second thin-film encapsulation layer TFEL2 can be disposed on the light-receiving element layer PDL. The second thin-film encapsulation layer TFEL2 can cover the source electrode 353 and drain electrode 354 of the switching transistor 350, the first connection electrode 381, and the third insulating film 365. The second thin-film encapsulation layer TFEL2 can prevent oxygen or moisture from penetrating into the light-receiving element layer PDL. The upper surface of the second thin-film encapsulation layer TFEL2 can be attached to the lower surface of the first substrate SUB1 by means of the adhesive component OCA.

[0241] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, it will be understood by those skilled in the art that the invention can be implemented in other specific forms without altering its technical concept or essential features. Therefore, the embodiments described above should be understood as exemplary in all respects, and not limiting.

Claims

1. A fingerprint sensor, comprising: Light-receiving element; The first transistor connects the second node and the third node based on the voltage of the first node, which serves as the first electrode of the light-receiving element; The second transistor connects the second node to the lead based on the scan signal; The third transistor supplies a reset voltage to the first node based on the first reset signal; The fourth transistor connects the first node and the second node based on the second reset signal; and The sixth transistor supplies the sampled voltage to the third node based on the second reset signal. During the first time period, the third transistor is turned on to supply the reset voltage to the first node, while the fourth and sixth transistors are turned off. The fourth transistor is turned on in a second time period after the first time period to connect the first node and the second node. The sixth transistor is turned on in a second time period after the first time period to supply the sampling voltage to the third node. The gate electrode of the third transistor is connected to the first reset line that supplies the first reset signal, and the source electrode of the third transistor is connected to the reset voltage line that supplies the reset voltage. The gate electrodes of the fourth transistor and the sixth transistor are connected together to the second reset line that transmits the second reset signal.

2. The fingerprint sensor as described in claim 1, wherein, The first electrode of the light-receiving element is connected to the gate electrode of the first transistor, and the second electrode of the light-receiving element receives a bias voltage.

3. The fingerprint sensor as described in claim 1, further comprising: The fifth transistor supplies a common voltage to the third node based on the scan signal.

4. The fingerprint sensor as described in claim 3, wherein, The light-receiving element receives reflected light during a third time period following the second time period, causing current to flow out of the first node.

5. The fingerprint sensor as described in claim 4, wherein, The fifth transistor supplies the common voltage to the third node during a fourth time period following the third time period.

6. The fingerprint sensor as described in claim 4, wherein, During a fourth time period following the third time period, the first transistor supplies output current to the second node based on the voltage of the first node.

7. The fingerprint sensor as described in claim 4, wherein, The second transistor connects the second node to the lead during a fourth time period following the third time period.

8. A display device, comprising: The display layer displays images; A fingerprint sensor layer, disposed on one side of the display layer, is equipped with multiple fingerprint sensors that receive reflected light to generate sensing signals; and The sensor driver receives sensing signals via leads connected to each of the plurality of fingerprint sensors. Each of the plurality of fingerprint sensors includes: Light-receiving element; The first transistor connects the second node and the third node based on the voltage of the first node, which serves as the first electrode of the light-receiving element; The second transistor connects the second node to the lead based on the scan signal; The third transistor supplies a reset voltage to the first node based on the first reset signal; A fourth transistor, connected to the first node and the second node based on a second reset signal; and The sixth transistor supplies the sampled voltage to the third node based on the second reset signal. During the first time period, the third transistor is turned on to supply the reset voltage to the first node, while the fourth and sixth transistors are turned off. The fourth transistor is turned on in a second time period after the first time period to connect the first node and the second node. The sixth transistor is turned on in a second time period after the first time period to supply the sampling voltage to the third node. The gate electrode of the third transistor is connected to the first reset line that supplies the first reset signal, and the source electrode of the third transistor is connected to the reset voltage line that supplies the reset voltage. The gate electrodes of the fourth transistor and the sixth transistor are connected together to the second reset line that transmits the second reset signal.

9. The display device as claimed in claim 8, wherein, Each of the plurality of fingerprint sensors also includes: The fifth transistor supplies a common voltage to the third node based on the scan signal.

10. The display device as claimed in claim 9, wherein, The first electrode of the light-receiving element is connected to the gate electrode of the first transistor, and the second electrode of the light-receiving element receives a bias voltage. The light-receiving element receives the reflected light during a third time period following the second time period, so that current flows from the first electrode to the second electrode.

11. The display device as claimed in claim 10, wherein, The fifth transistor supplies the common voltage to the third node during a fourth time period following the third time period. During the fourth time period, the first transistor supplies output current to the second node based on the voltage of the first node. The second transistor connects the second node to the lead during the fourth time period.

12. The display device of claim 8, further comprising: An optical system is arranged between the display layer and the fingerprint sensor layer and is equipped with multiple holes.

13. The display device as claimed in claim 8, wherein, The first electrode of the light-receiving element is disposed on the base component of the fingerprint sensor layer and connected to the first electrode of the third transistor or the first electrode of the fourth transistor.

14. The display device as claimed in claim 13, wherein, The light-receiving element includes: A light-receiving layer is disposed on one side of the first electrode of the light-receiving element; and The second electrode is disposed on one side of the light-receiving layer to receive the bias voltage.

15. The display device as claimed in claim 14, wherein, The second electrode comprises a transparent conductive material.

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