Display device, fingerprint authentication method, and fingerprint detector

Abstract

Exemplary embodiments of the present invention relate to a display apparatus, a method of authenticating a fingerprint, and a fingerprint detector. A display apparatus includes a fingerprint sensor including a first layer having at least one light sensor to generate a fingerprint image corresponding to reflected light from a fingerprint contact surface, a light emitting element to transmit light reflected by a fingerprint, and a second layer including a pinhole to allow the reflected light to be incident on the at least one light sensor, and a fingerprint detector to receive the fingerprint image from the fingerprint sensor, extract a first image corresponding to a first area of a fingerprint and a second image corresponding to a second area of the fingerprint, compare the first image with the second image to determine a similarity, and perform a fingerprint authentication based on the similarity determination, wherein the first area of the fingerprint is in contact with the fingerprint contact surface and the second area of the fingerprint is not in contact with the fingerprint contact surface.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2019-0102536, filed on August 21, 2019, which is hereby incorporated by reference for all purposes as if fully set forth herein. Technical Field

[0003] Exemplary embodiments of the present invention generally relate to display devices, and more particularly, to a display device including a fingerprint sensor, a method of authenticating a fingerprint (ie, a fingerprint authentication method), and a fingerprint detector. Background Art

[0004] Electronic devices, including portable or mobile computing devices, such as laptops, tablets, smartphones, and gaming systems, may employ user authentication mechanisms to protect personal data and prevent unauthorized access. User authentication on electronic devices can be performed using one or more forms of biometric identifiers, which can be used alone or in conjunction with existing password authentication methods. A popular form of biometric identifier is a person's fingerprint pattern. A fingerprint sensor can be built into the electronic device to read the user's fingerprint pattern so that the electronic device can be unlocked only by authorized users by authenticating the user's fingerprint pattern.

[0005] The above information disclosed in this Background section is only for understanding the background of the present inventive concept and therefore it may contain information that does not constitute prior art. Summary of the Invention

[0006] A display device constructed according to the principles and exemplary embodiments of the present invention includes a fingerprint sensor that can easily identify forged fingerprints (fingerprints that are modified or imitated, etc.) by simultaneously acquiring an image of a fingerprint in contact with a fingerprint contact surface and a peripheral image of the fingerprint for user authentication purposes and determining the similarity between the fingerprint image and the peripheral image of the fingerprint.

[0007] A fingerprint authentication method according to the principles and exemplary embodiments of the present invention may be performed by a fingerprint sensor of a display device.

[0008] A display device constructed in accordance with the principles and exemplary embodiments of the present invention can easily determine at least one of the following: whether a fingerprint is a forged fingerprint without requiring a separate biometric sensor for determining whether the fingerprint is a biometric fingerprint; and whether a fingerprint is a forged fingerprint without requiring a sensor (e.g., a color sensor) for determining whether the fingerprint is a forged fingerprint by using color characteristics of light reflected from the fingerprint. Furthermore, a display device constructed in accordance with the principles and exemplary embodiments of the present invention can reduce the resulting manufacturing costs compared to when a separate biometric sensor and / or a separate color sensor are required.

[0009] Additional features of the inventive concept will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the inventive concept.

[0010] According to one aspect of the present invention, a display device includes: a fingerprint sensor including a first layer having at least one light sensor to generate a fingerprint image corresponding to reflected light from a fingerprint contact surface, a light-emitting element that transmits light reflected from the fingerprint, and a second layer including a pinhole to allow the reflected light to be incident on the at least one light sensor; and a fingerprint detector that receives the fingerprint image from the fingerprint sensor, extracts a first image corresponding to a first area of ​​the fingerprint and a second image corresponding to a second area of ​​the fingerprint, compares the first image and the second image to determine similarity, and performs fingerprint authentication based on the similarity determination, wherein the first area of ​​the fingerprint is in contact with the fingerprint contact surface and the second area of ​​the fingerprint is not in contact with the fingerprint contact surface.

[0011] The fingerprint detector may include: a fingerprint image extractor that receives the fingerprint image from the first layer to extract a first image and a second image; an image processor that performs preprocessing on the extracted first image and the second image; a comparator that determines similarity by comparing the preprocessed first image and the preprocessed second image; and an authentication unit that authenticates the fingerprint based on the determination of the comparator.

[0012] The comparator may be configured to determine whether the fingerprint is a biometric fingerprint and whether the preprocessed first image and the preprocessed second image have similar patterns by comparing the brightness of the preprocessed first image with the brightness of the preprocessed second image.

[0013] The comparator may be configured to determine similarity of patterns of the preprocessed first image and the preprocessed second image by analyzing continuity of at least one of valleys and ridges of the preprocessed second image with at least one of valleys and ridges of the preprocessed first image.

[0014] When brightness of the preprocessed first image and brightness of the preprocessed second image are different from each other and the preprocessed first image and the preprocessed second image have similar patterns, the comparator may be configured to determine that the fingerprint can be a biometric fingerprint.

[0015] When the brightness of the preprocessed first image and the brightness of the preprocessed second image are different and the preprocessed first image and the preprocessed second image do not have similar patterns, the comparator may be configured to determine that the fingerprint is likely to be forged.

[0016] The fingerprint image extractor may be configured to extract the first image and the second image by differentiating an amount of light reflected in a first area of ​​the fingerprint from an amount of light reflected in a second area of ​​the fingerprint.

[0017] The first layer may include a light sensing array layer and the second layer may include a selective light transmitting layer having a light blocking pattern located between pinholes, and wherein the pinholes may be configured to focus light emitted from corresponding light emitting elements and subsequently reflected from the fingerprint.

[0018] The pinholes may comprise an array.

[0019] The fingerprint detector may include: a fingerprint image extractor that receives a fingerprint image from a light sensing array layer to extract a first image and a second image; an image processor that preprocesses the extracted first image and second image and synthesizes the first image and the second image; a comparator that determines whether the second image in the synthesized image from the image processor includes the array; and an authentication unit that authenticates the fingerprint based on the determination of the comparator.

[0020] When the second image includes the array, the comparator may be configured to determine that the fingerprint image is forged.

[0021] When the second image does not include the array, the comparator may be configured to determine that the fingerprint image may be a biometric fingerprint.

[0022] The second region may be located at a periphery of the first region.

[0023] The array may comprise a grid arrangement.

[0024] The comparator may include a similarity determiner configured to determine the similar pattern by analyzing continuity of valleys and ridges of the pre-processed second image with valleys and ridges of the pre-processed first image.

[0025] According to another aspect of the present invention, a method for authenticating a fingerprint is provided for a display device having a fingerprint sensor, the method comprising the following steps: receiving a fingerprint image corresponding to a fingerprint of a user in contact with a fingerprint contact surface by sensing light reflected by the fingerprint; extracting from the fingerprint image a first image corresponding to a first area of ​​the fingerprint in contact with the fingerprint contact surface and a second image corresponding to a second area of ​​the fingerprint located at the periphery of the first area of ​​the fingerprint; comparing the extracted first image and the second image; and authenticating the fingerprint based on the comparison of the extracted first image and the second image.

[0026] An image pre-processing step may be performed on the extracted first image and the second image.

[0027] The step of determining that the fingerprint is a biometric fingerprint may be performed by using the brightness of the preprocessed first image and the brightness of the preprocessed second image to determine that the preprocessed first image and the preprocessed second image have similar patterns.

[0028] When the preprocessed first image and the preprocessed second image have valleys and ridges that are continuous with each other, the first image and the second image may have similar patterns.

[0029] It may be determined that the fingerprint is a biometric fingerprint when the brightness of the first image and the second image are different from each other and the first image and the second image have similar patterns.

[0030] It can be determined that the fingerprint is forged when the brightness of the first image and the second image are different from each other and the first image and the second image do not have similar patterns.

[0031] The fingerprint sensor may have: a first layer including at least one light sensor to sense light reflected by the fingerprint; a second layer including pinholes arranged in an array to transmit incident light onto the light sensor, and the method may further include the step of: when the second image includes the array, determining that the fingerprint is a forged fingerprint.

[0032] When the pre-processed second image does not include the array, it can be determined that the fingerprint is a biometric fingerprint.

[0033] According to another aspect of the present invention, a fingerprint detector in a display device is used to distinguish a biometric fingerprint from a forged fingerprint. The fingerprint detector may include: a fingerprint image extractor that receives a fingerprint image from a light sensing array layer to extract a first image corresponding to a first area of ​​the fingerprint image of the fingerprint in contact with a fingerprint contact surface, and a second image corresponding to a second area of ​​the fingerprint image not in contact with the fingerprint contact surface; an image processor that performs preprocessing on the extracted first and second images; a comparator that compares the preprocessed first image and the preprocessed second image; and an authentication unit that authenticates the fingerprint based on a determination of the comparator.

[0034] The second area of ​​the fingerprint image may be located at the periphery of the fingerprint.

[0035] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and together with the description serve to explain the inventive concept.

[0037] Figure 1A and Figure 1B It is a block diagram schematically illustrating an exemplary embodiment of a display device constructed according to the principles of the present invention.

[0038] Figure 2 Yes Figure 1A and Figure 1B sectional view schematically illustrating the display device shown in FIG.

[0039] Figure 3 Yes Figure 2 Schematic diagram of an exemplary embodiment of a selective light-transmitting layer is shown in FIG.

[0040] Figure 4 is a perspective view schematically illustrating an exemplary embodiment of a sensing area of ​​a display device including a fingerprint sensor constructed according to the principles of the present invention.

[0041] 5A to 5D is a plan view illustrating an exemplary embodiment of the arrangement of fingerprint pixels, pinholes, and light sensors constructed according to the principles of the present invention.

[0042] Figure 6 yes Figure 2 An enlarged cross-sectional view of the area EA is shown in FIG.

[0043] Figure 7 is a schematic cross-sectional view of an exemplary embodiment of a display device.

[0044] Figure 8 It is from Figure 7 An exemplary embodiment of a user fingerprint image captured by the light sensing array layer shown in FIG. 1 is illustrated in FIG.

[0045] Figure 9 An image of a user's fingerprint in contact with a fingerprint contact surface of an exemplary embodiment of a display device is illustrated, including magnified images of a first region and a second region of the fingerprint.

[0046] Figure 10An image of a forged fingerprint in contact with a fingerprint contact surface of an exemplary embodiment of a display device is illustrated, including magnified images of a first region and a second region of the forged fingerprint.

[0047] Figure 11 Yes Figure 1A and Figure 1B A block diagram schematically illustrates an exemplary embodiment of a fingerprint detector shown in FIG.

[0048] Figure 12A Yes Figure 11 An image illustrating an exemplary biometric fingerprint image used in the similarity determination method performed in the similarity determiner shown in FIG.

[0049] Figure 12B Yes Figure 11 An image illustrating another exemplary biometric fingerprint image used in the similarity determination method performed in the similarity determiner shown in FIG.

[0050] Figure 13 According to the principle of the present invention Figure 11 Flowchart illustrating an exemplary fingerprint authentication method of the fingerprint sensor shown in FIG.

[0051] Figure 14 According to the principle of the present invention Figure 11 Flowchart illustrating another exemplary fingerprint authentication method of the fingerprint sensor shown in FIG. DETAILED DESCRIPTION

[0052] In the following description, for the purpose of illustration, many specific details are set forth in order to provide a thorough understanding of various exemplary embodiments or implementations of the present invention. As used herein, "embodiment" and "implementation" are interchangeable terms that are non-limiting examples of devices or methods employing one or more inventive concepts disclosed herein. However, it will be apparent that various exemplary embodiments may be implemented without these specific details or utilizing one or more equivalent arrangements. In other cases, well-known structures and devices are shown in the form of block diagrams to avoid unnecessarily blurring various exemplary embodiments. In addition, various exemplary embodiments may be different, but need not be exclusive. For example, without departing from the present invention, the specific shape, configuration, and characteristics of an exemplary embodiment may be used or implemented in another exemplary embodiment.

[0053] Unless otherwise indicated, the exemplary embodiments shown are to be understood as providing exemplary features of different details of some ways in which the inventive concept can be implemented in practice. Therefore, unless otherwise indicated, the features, components, modules, layers, films, panels, regions and / or aspects of the various embodiments (hereinafter individually or collectively referred to as "elements") may be combined, separated, interchanged and / or rearranged in other ways without departing from the inventive concept.

[0054] Cross hatching and / or shading are generally provided in the drawings to illustrate the boundaries between adjacent elements. As such, unless otherwise specified, the presence or absence of cross hatching or shading does not convey or indicate any preference or requirement for a particular material, material properties, size, ratio, commonality between the elements shown, and / or any other characteristics, attributes, properties, etc. of the elements. In addition, in the drawings, the size and relative size of the elements may be exaggerated for clarity and / or descriptive purposes. When the exemplary embodiments can be implemented differently, the specific processing sequence can be performed differently from the described sequence. For example, two consecutively described processes can be performed substantially simultaneously or in an order opposite to the described sequence. In addition, the same reference numerals represent the same elements.

[0055] When an element or layer is referred to as being "on," "connected to," or "coupled to" another element or layer, it can be directly on, directly connected to, or directly coupled to the other element or layer, or there may be intervening elements or layers. However, when an element or layer is referred to as being "directly on," "directly connected to," or "directly coupled to" another element or layer, there are no intervening elements or layers. For this purpose, the term "connected" may refer to a physical connection, an electrical connection, and / or a fluid connection, with or without intervening elements. In addition, the DR1 axis, the DR2 axis, and the DR3 axis are not limited to the three axes of a rectangular coordinate system such as the x-axis, the y-axis, and the z-axis, and may be interpreted in a broader sense. For example, the DR1 axis, the DR2 axis, and the DR3 axis may be perpendicular to each other, or may represent different directions that are not perpendicular to each other. For the purposes of this disclosure, “at least one of X, Y, and Z” and “at least one selected from the group consisting of X, Y, and Z” may be interpreted as only X, only Y, only Z, or any combination of two or more of X, Y, and Z, such as, for example, XYZ, XYY, YZ, and ZZ. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items.

[0056] Although the terms "first," "second," etc. may be used herein to describe various types of elements, these elements should not be limited by these terms. These terms are used to distinguish one element from another. Thus, the first element discussed below may be referred to as the second element without departing from the teachings of the present disclosure.

[0057] For descriptive purposes, spatially relative terms such as "under," "beneath," "beneath," "down," "over," "upper," "above," "higher," and "side" (e.g., in a "sidewall") may be used herein and thereby to describe the relationship of one element(s) to another element(s) as shown in the accompanying drawings. Spatially relative terms are intended to encompass different orientations of the device in use, operation, and / or manufacture in addition to the orientations depicted in the accompanying drawings. For example, if the device in the drawings is turned over, an element described as "under" or "beneath" other elements or features would subsequently be oriented "over" the other elements or features. Thus, the exemplary term "under" can encompass both above and below orientations. Furthermore, the device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations), and thus, the spatially relative descriptors used herein should be interpreted accordingly.

[0058] The terms used herein are for the purpose of describing specific embodiments and are not intended to be limiting. As used herein, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" are also intended to include the plural forms. In addition, the terms "comprise", "include", "contain", and / or "have" when used in this specification illustrate the presence of stated features, integral bodies, steps, operations, elements, components, and / or their groups, but do not exclude the presence or addition of one or more other features, integral bodies, steps, operations, elements, components, and / or their groups. It is also noted that, as used herein, the terms "substantially", "approximately", and other similar terms are used as approximate terms rather than terms of degree, and thus, are used to explain the inherent deviations of measured values, calculated values, and / or provided values ​​that will be recognized by those of ordinary skill in the art.

[0059] Various exemplary embodiments are described herein with reference to the following cross-sectional illustrations and / or exploded illustrations, which are schematic diagrams of idealized exemplary embodiments and / or intermediate structures. Thus, variations in the shapes of the illustrations due to, for example, manufacturing techniques and / or margins are to be expected. Thus, the exemplary embodiments disclosed herein should not be construed as limited to the specific illustrated shapes of regions, but rather include shape deviations resulting from, for example, manufacturing. In this manner, the regions illustrated in the accompanying drawings may be schematic in nature and the shapes of these regions may not reflect the actual shapes of regions of the device, and thus, are not necessarily intended to be limiting.

[0060] As used herein, the term "light" refers to electromagnetic radiation of any wavelength that propagates at a speed of approximately 300,000,000 meters per second in a vacuum, and specifically refers to at least one of visible light, ultraviolet light, and infrared light.

[0061] Exemplary embodiments of the apparatus and methods disclosed herein (including Figure 11 、 Figure 13 and Figure 14 Those depicted in the and / or one or more components thereof) can be implemented by one or more general and / or special-purpose components such as one or more discrete circuits, digital signal processing chips, integrated circuits, application-specific integrated circuits, microprocessors, processors, programmable arrays, field programmable arrays and / or instruction set processors.

[0062] According to one or more exemplary embodiments, the features, functions, processes, etc. described herein may be implemented by software, hardware (e.g., a general-purpose processor, a digital signal processing (DSP) chip, an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), etc.), firmware, or a combination thereof. In this manner, Figure 13 and Figure 14 The method and / or one or more components thereof may include or be associated with one or more memories including code (e.g., instructions) configured to cause Figure 13 and Figure 14 methods and / or one or more components thereof to perform one or more of the features, functions, processes, etc. described herein.

[0063] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure is a part. Unless expressly defined as such herein, terms such as those defined in general dictionaries should be interpreted as having a meaning consistent with the meaning of the terms in the context of the relevant art and should not be interpreted in an idealized or overly formal sense.

[0064] Figure 1A and Figure 1B 1 is a block diagram schematically illustrating an exemplary embodiment of a display device constructed according to the principles of the present invention. More specifically, Figure 1A and Figure 1B 1 is a plan view schematically illustrating a display panel and a driving circuit for driving the display panel provided in a display device according to an exemplary embodiment of the present invention. Figure 1A and Figure 1B 1 and 2. The display panel and the driving circuit are shown separately in FIG. 3 , but the exemplary embodiments of the present invention are not limited thereto. In some exemplary embodiments, all or part of the driving circuit may be implemented integrally with the display panel on the display panel.

[0065] refer to Figure 1A and Figure 1B According to an exemplary embodiment of the present invention, the display device DD may be provided in various shapes. For example, the display device DD may be provided in the shape of a substantially rectangular plate having two pairs of substantially parallel sides. The display device DD may display visual information such as text, video, pictures, or two-dimensional or three-dimensional images in the direction in which the image is displayed.

[0066] The entire display device DD or at least a portion thereof may be flexible. For example, the display device DD may be flexible throughout its entire area, or in an area corresponding to the flexible area. When the entire display device DD is flexible, the display device DD may be a rollable display device. When a portion of the display device DD is flexible, the display device DD may be a foldable display device.

[0067] The display device DD may include a display panel PN and a driving circuit DCP for driving the display panel PN.

[0068] The display panel PN may include a display area DA and a non-display area NDA. The display area DA may be provided with pixels PXL for displaying an image, and the non-display area NDA may be located at least on one side of the display area DA. For example, the non-display area NDA may be provided in a shape surrounding the display area DA.

[0069] A plurality of pixels PXL may be provided in the display area DA. In some exemplary embodiments, each pixel PXL may include at least one light-emitting element. In some exemplary embodiments, the light-emitting element may be a light-emitting unit including an organic light-emitting diode or an ultra-small inorganic light-emitting diode having a size in the micrometer or nanometer range, but exemplary embodiments of the present invention are not limited thereto. The display device DD may drive the pixels PXL corresponding to input image data to display an image in the display area DA.

[0070] The non-display area NDA is a region surrounding at least one side of the display area DA and may be a region other than the display area DA. In some exemplary embodiments, the non-display area NDA may include a wiring region, a pad region, and / or various dummy regions.

[0071] In an exemplary embodiment of the present invention, an area of ​​the display device DD may be a sensing area SA capable of sensing a user's fingerprint, etc. That is, at least a portion of the display area DA may be the sensing area SA. The sensing area SA may include at least some of the pixels PXL provided in the display area DA.

[0072] In some exemplary embodiments, Figure 1A As shown in , only a portion of the display area DA may be set as the sensing area SA. In other embodiments, as Figure 1B As shown in , the entire display area DA can be set as the sensing area SA. When the entire display area DA is set as the sensing area SA, the non-display area NDA surrounding the display area DA can be set as the non-sensing area NSA. A plurality of light sensors PSR can be arranged in the sensing area SA together with a plurality of pixels PXL.

[0073] The light sensor PSR may be provided on a surface of the display device DD that faces a surface on which an image is displayed (e.g., an image display surface). That is, the light sensor PSR may be provided on a surface that does not display an image. The light sensor PSR may use a light-emitting element as a light source for fingerprint sensing, etc., which is provided in at least one representative pixel PXL provided in the sensing area SA or at the periphery of the sensing area SA. To this end, the light sensor PSR may overlap with at least some of the pixels PXL provided in the sensing area SA or at the periphery of the sensing area SA.

[0074] The light sensor PSR, together with the pixels PXL of the sensing area SA (particularly the light-emitting elements provided in the pixels PXL), can constitute a fingerprint sensor. That is, the light sensor PSR can sense light emitted from the light-emitting elements and then reflected by the user, and can sense the user's fingerprint by detecting the reflected light. Although the above embodiment describes the light sensor PSR as being used for fingerprint sensing, the exemplary embodiments of the present invention are not limited to this. In some embodiments, in addition to fingerprint sensing, the light sensor PSR can also be used to perform various functions such as a touch sensor and a scanner.

[0075] The display device DD according to an exemplary embodiment of the present invention can sense the shape or pattern of an object located on the display device DD by using a light sensor PSR arranged in a sensing area SA included in the display area DA. As an example, the display device DD can sense a user's fingerprint. In addition, the display device DD according to an exemplary embodiment of the present invention can sense a user's fingerprint by using light emitted from pixels PXL. As described above, when a display device with a built-in fingerprint sensor is implemented by using pixels PXL as a light source without having a separate external light source, the thickness of the display device DD can be reduced, and the manufacturing cost of the display device DD can be reduced. However, the exemplary embodiments of the present invention are not limited to this, and a separate external light source for fingerprint sensing can be adopted.

[0076] The driver circuit DCP can drive the display panel PN. For example, the driver circuit DCP can output a data signal corresponding to image data to the display panel PN, or output a drive signal for the light sensor PSR and receive an electrical signal (e.g., a sensing signal) from the light sensor PSR. The driver circuit DCP can detect the shape of a user's fingerprint using the electrical signal.

[0077] In some exemplary embodiments, the driving circuit DCP may include a panel driver PNDP and a fingerprint sensor FPDP. Figure 1A and Figure 1B , the panel driver PNDP and the fingerprint sensor FPDP are separated from each other, but the exemplary embodiments of the present invention are not limited thereto. For example, at least a portion of the fingerprint sensor FPDP may be integrated with the panel driver PNDP or operate in conjunction with the panel driver PNDP.

[0078] The panel driver PNDP may supply data signals corresponding to image data to the pixels PXL of the display area DA by sequentially scanning the pixels PXL. Thus, the display panel PN may display an image corresponding to the image data.

[0079] In some exemplary embodiments, the panel driver PNDP may supply a driving signal for fingerprint sensing to the pixels PXL. The driving signal may be provided to allow the pixels PXL to operate as a light source for the light sensor PSR by emitting light. The driving signal for fingerprint sensing may be transmitted to the pixels PXL provided in a specific area of ​​the display panel PN (e.g., the pixels PXL provided in the sensing area SA). In various exemplary embodiments, the driving signal for fingerprint sensing may be transmitted to the pixels PXL in the sensing area SA by the fingerprint detector FPDP.

[0080] The fingerprint detector FPDP may transmit a driving signal (eg, a driving voltage) for driving the light sensor PSR to the light sensor PSR and detect a fingerprint of the user based on an electrical signal received from the light sensor PSR.

[0081] Figure 2 Yes Figure 1A and Figure 1B sectional view schematically illustrating the display device shown in FIG. Figure 3 Yes Figure 2 Schematic diagram of a selective light transmission layer shown in FIG.

[0082] refer to Figure 1A 、 Figure 1B 、 Figure 2 and Figure 3 The display device DD according to the illustrated exemplary embodiment may include a display panel PN, a touch sensor TS, and a window WD. In addition, the display device DD may further include a light sensing array layer LSL disposed on any one surface of the display panel PN.

[0083] The display device DD may include a first surface SF1 on which an image is displayed and a second surface SF2 facing the first surface SF1, and the light sensing array layer LSL may be closer to the second surface SF2 than the first surface SF1. In an exemplary embodiment, the first surface SF1 of the display device DD may be a display surface on which an image is displayed. A region of the first surface SF1 of the display device DD may be a fingerprint contact surface that comes into contact with a user's fingerprint.

[0084] The display panel PN can display an image. The type of the display panel PN that displays the image is not particularly limited. The display panel PN may be a self-luminous display panel such as an organic light-emitting display (OLED) panel. Alternatively, the display panel PN may be a non-self-luminous display panel such as a liquid crystal display (LCD) panel, an electrophoretic display (EPD) panel, or an electrowetting display (EWD) panel. When a non-self-luminous display panel is used as the display panel PN of the display device DD according to an exemplary embodiment of the present invention, the display device DD may further include a backlight unit for supplying light to the display panel PN.

[0085] The display panel PN may include a substrate SUB, a selective light transmission layer LBL, a display module DM, and a thin film encapsulation TFE. In an exemplary embodiment of the present invention, the display module DM may include a display element layer DPL including a light emitting element LD and a pixel circuit layer PCL including circuit elements for driving the light emitting element LD.

[0086] The substrate SUB is a base substrate of the display panel PN and may be a substantially transparent transmissive substrate. In some exemplary embodiments, the substrate SUB may be a rigid substrate including glass or tempered glass, or a flexible substrate made of plastic. In exemplary embodiments of the present invention, the substrate SUB may be a flexible substrate.

[0087] The pixel circuit layer PCL may be provided on a surface (e.g., an upper surface) of the substrate SUB and include at least one conductive layer. In an example, the pixel circuit layer PCL may include a plurality of circuit elements formed in each pixel area PXA to constitute a pixel circuit corresponding to a representative pixel PXL, and wiring for supplying various power supplies and signals for driving the pixel PXL. Therefore, the pixel circuit layer PCL may include various circuit elements such as at least one transistor and at least one capacitor, and a plurality of conductive layers for constituting wiring connected to the circuit elements. In addition, the pixel circuit layer PCL may include at least one insulating layer provided between the plurality of conductive layers. In addition, the pixel circuit layer PCL may include a fan-out line provided in the non-display area NDA of the display panel PN to supply power and signals, which corresponds to the wiring connected to the pixel PXL.

[0088] The display element layer DPL may be disposed on one surface of a substrate SUB including a pixel circuit layer PCL. In some exemplary embodiments, the display element layer DPL may include a plurality of light-emitting elements LD connected to circuit elements and / or wiring of the pixel circuit layer PCL via contact holes or the like. In some examples, the display element layer DPL may include at least one light-emitting element LD disposed in each pixel area PXA. In exemplary embodiments of the present invention, the light-emitting element LD may be an organic light-emitting diode or an ultra-small light-emitting element using a structure obtained by growing an inorganic crystal structure.

[0089] A thin film encapsulation TFE may be disposed on top of the display element layer DPL to cover at least the display area DA.

[0090] The selective light transmission layer LBL may be located between the substrate SUB and the pixel circuit layer PCL at least in the sensing area SA. In an example, the selective light transmission layer LBL may be disposed on one surface of the substrate SUB. The selective light transmission layer LBL may include a plurality of pinholes PIH and a light blocking pattern LBP.

[0091] The light blocking pattern LBP may be made of a light blocking material and / or a light absorbing material. In an example, the light blocking pattern LBP may be an opaque metal layer disposed between adjacent pinholes PIH. The pinhole PIH may be a through hole penetrating at least one region of the light blocking pattern LBP.

[0092] The selective light-transmitting layer LBL may include a plurality of pinholes PIH uniformly provided in the light-blocking pattern LBP to have a certain size and a certain distance. However, the exemplary embodiments of the present invention are not limited thereto, and the size, shape, number, resolution, and / or arrangement structure of the pinholes PIH may be variously modified. For example, the pinholes PIH may be irregularly provided in the light-blocking pattern LBP.

[0093] The pinholes PIH may be formed to have a size and distance sufficient to sense a clearer fingerprint shape while preventing diffraction of the incident light. For example, the width of each pinhole PIH may be set to be about ten times or more the wavelength of the incident light to prevent diffraction of the light. The pinholes PIH may be spaced apart from each other at a constant distance. The pinholes PIH may be formed as follows: Figure 3 The grid arrangement shown in . The distance between the pinholes PIH can be determined based on the distance between the selective light transmission layer LBL and the light sensing array layer LSL, the wavelength of the incident light, and the field of view (FOV) required by the pinhole PIH. For example, three or fifteen pixels PXL can be located between two adjacent (or adjacent) pinholes PIH to sense a relatively clear fingerprint shape, but exemplary embodiments of the present invention are not limited thereto. In some exemplary embodiments, fifteen or more pixels PXL or three or fewer pixels PXL can be located between two adjacent (or adjacent) pinholes PIH.

[0094] Each pinhole PIH may be provided in a substantially circular shape when viewed in a plan view, but exemplary embodiments of the present invention are not limited thereto. In some exemplary embodiments, the pinhole PIH may be provided in various shapes including a substantially regular triangle, a substantially regular square, and a substantially regular hexagon. The pinholes PIH may have a substantially uniform density (resolution) throughout the sensing area SA, but exemplary embodiments of the present invention are not limited thereto. In some exemplary embodiments, the density of the pinholes PIH may be higher in one area of ​​the sensing area SA and lower in another area of ​​the sensing area SA. Each pinhole PIH may be an effective hole having a focal point F, and the reflected light RL incident on the light sensing array layer LSL converges on the focal point F.

[0095] Some light incident on the selective light-transmitting layer LBL may be blocked by the light-blocking pattern LBP, while some other light may reach the light sensing array layer LSL by passing through the pinholes PIH. The selective light-transmitting layer LBL may selectively transmit reflected light RL from an object (e.g., a user's fingerprint) located on the first surface SF1 of the display device DD. The pinholes PIH may refer to optical holes. Each pinhole PIH may be a through hole or a light-transmitting hole.

[0096] In the above display device DD, the selective light transmission layer LBL is provided between the display element layer DPL and the light sensing array layer LSL to allow only some light (eg, reflected light RL) to selectively transmit therethrough, thereby constituting an optical system for controlling a light path and the like.

[0097] The selective light-transmitting layer LBL may correspond to the display area DA of the display panel PN and have a size (or area) greater than or equal to the size (or area) of the display area DA. In an example, when the sensing area SA is the entire display area DA, the selective light-transmitting layer LBL may have a size (or area) greater than or equal to the size (or area) of the display area DA. In another example, when the sensing area SA is a portion of the display area DA, the selective light-transmitting layer LBL may have a size (or area) greater than the size (or area) of the sensing area SA and smaller than the size (or area) of the display area DA, or may have a size (or area) equal to the size (or area) of the sensing area SA. In yet another example, when the sensing area SA is a portion of the display area DA, the selective light-transmitting layer LBL may have a size (or area) equal to the size (or area) of the display area DA.

[0098] The light sensing array layer LSL may be attached to the other surface (or lower surface) of the substrate SUB to overlap at least one region of the display panel PN. In some examples, the light sensing array layer LSL may be disposed to overlap the display panel PN in the sensing area SA. The light sensing array layer LSL may include a plurality of light sensors PSR dispersed at a predetermined density (or resolution) and / or a predetermined distance (pitch).

[0099] The light sensor PSR may be implemented using a semiconductor layer or a semiconductor chip on which a plurality of photoelectric conversion elements (e.g., photodiodes, phototransistors, photogates, pinned photodiodes, etc.) are formed. In some exemplary embodiments, the light sensor PSR may be implemented using a semiconductor layer on which an image sensor such as a CMOS image sensor (CIS) or a charge coupled device (CCD) is formed.

[0100] The light sensors PSR of the light sensing array layer LSL can output electrical signals corresponding to the reflected light RL received by passing through the pinholes PIH as sensing signals. The reflected light RL received by the corresponding light sensors PSR can have different optical characteristics (e.g., different frequencies, different wavelengths, different amplitudes, etc.) depending on whether the reflected light RL is caused by valleys or ridges of the fingerprint formed on the user's finger. Therefore, the light sensors PSR can output sensing signals (or electrical signals) having different electrical characteristics corresponding to the optical characteristics of the reflected light RL. The sensing signals output by the light sensors PSR can be converted into image data for use in identifying the user's fingerprint.

[0101] In an exemplary embodiment of the present invention, the light sensing array layer LSL including the light sensors PSR and the selective light transmission layer LBL including the pinholes PIH may constitute an optical system of a fingerprint sensor in the sensing area SA of the display device DD.

[0102] In an exemplary embodiment of the present invention, when the pixels PXL, pinholes PIH, and photosensors PSR of the sensing area SA are aligned, the diameter d and thickness T of each pinhole PIH may correspond to the following parameters for determining a viewing angle θ relative to the upper and lower surfaces based on each pinhole PIH. The size, distance, and / or resolution of the light sensing array layer LSL including the photosensors PSR and the selective light transmission layer LBL including the pinholes PIH may be controlled to determine the above parameters.

[0103] The touch sensor TS may be provided on a surface of the display panel PN on which an image is displayed to receive a user's touch input and / or hover input. The touch sensor TS may sense touch capacitance by contact and / or proximity of a separate input device, such as a user's hand or a similar conductor, to identify a touch input and / or hover input of the display device DD. A touch input may refer to a user's hand or a separate input device directly touching (or contacting) the touch sensor TS, and a hover input may refer to a user's hand or a separate input device being near the display device DD including the touch sensor TS but not touching the touch sensor TS.

[0104] Furthermore, the touch sensor TS can sense a user's touch operation and move an object displayed on the display device DD from a location where the object was originally displayed to another location. A touch operation may include at least one of a single-point touch, a multi-point touch, and a touch gesture. In an example, various touch operations may include specific gestures, such as an operation to zoom in or out text or an image by moving the user's finger a certain distance while the user's finger is touching the touch surface of the touch sensor TS.

[0105] The window WD is a member disposed at the uppermost end of the display device DD including the display panel PN and can be a substantially transparent, light-transmitting substrate. The window WD allows images from the display panel PN to pass therethrough and reduces external impact, thereby preventing the display panel PN from cracking or malfunctioning due to external impact. External impact can refer to external forces, such as pressure or stress, that can cause defects in the display panel PN. The window WD can include a rigid or flexible substrate, and the material constituting the window WD is not particularly limited.

[0106] The following briefly describes the fingerprint sensing method of the display device DD according to the above-described embodiment. During the fingerprint sensing period in which the light sensor PSR is activated, when the user's finger (e.g., fingerprint area) is in contact with or close to the sensing area SA, the light-emitting element LD provided in the pixel PXL of the sensing area SA may emit light EL. In an example, the light-emitting elements LD provided in all pixels PXL of the sensing area SA may emit light EL simultaneously or sequentially during the fingerprint sensing period. Alternatively, the light-emitting elements LD included only in some of the pixels PXL of the sensing area SA may emit light EL at a predetermined distance, or the light-emitting elements LD emitting light EL of a specific color (e.g., light of a short wavelength band such as blue light) included only in some of the pixels PXL of the sensing area SA may selectively emit light EL.

[0107] Some of the light EL emitted from the pixel PXL may be reflected from the user's finger and incident on the light sensor PSR by passing through a pinhole PIH formed in the selective light-transmitting layer LBL of the display device DD. The shape (fingerprint pattern) of the user's fingerprint can be detected based on the difference in the amount and / or wavelength of the reflected light RL reflected from the ridges and valleys of the fingerprint.

[0108] Figure 4 is a schematic perspective view schematically illustrating an exemplary embodiment of a sensing area of ​​a display device including a fingerprint sensor constructed according to the principles of the present invention.

[0109] refer to Figures 1A to 4 The display device DD may include a display panel PN, a window WD, and a fingerprint sensor FPS. The touch sensor TS may be located between the display panel PN and the window WD.

[0110] The fingerprint sensor FPS may be an optical fingerprint sensor that senses light (or radiation) EL reflected from the ridges and valleys between the ridges of a user's fingerprint, thereby identifying the user's fingerprint. In embodiments, the fingerprint sensor FPS may include: a selective light-transmitting layer LBL formed to allow reflected light RL reflected from the fingerprint to pass therethrough; and a light sensing array layer LSL formed to generate an electrical signal by sensing the reflected light RL that passes through the selective light-transmitting layer LBL.

[0111] exist Figure 4 , the selective light transmission layer LBL is illustrated as a component independent of the display panel PN in order to conveniently describe the selective light transmission layer LBL and the light sensing array layer LSL constituting the fingerprint sensor FPS, but exemplary embodiments of the present invention are not limited thereto.

[0112] In some exemplary embodiments, in the packaging process of the light sensing array layer LSL when implementing the fingerprint sensor FPS, the selective light transmission layer LBL may be stacked on the light sensing array layer LSL. Alternatively, in the process for implementing the light sensing array layer LSL, the selective light transmission layer LBL may be stacked in the form of a layer on at least one layer constituting the light sensing array layer LSL. That is, the fingerprint sensor FPS may be implemented in the form of the selective light transmission layer LBL being embedded in the light sensing array layer LSL, and the packaging process may be performed on the light sensing array layer LSL having the selective light transmission layer LBL embedded therein. That is, in some exemplary embodiments, the selective light transmission layer LBL and the light sensing array layer LSL may be formed integrally. However, exemplary embodiments of the present invention are not limited thereto. In some exemplary embodiments, as Figure 2 As shown in , the selective light transmission layer LBL may be disposed between the substrate SUB and the pixel circuit layer PCL of the display panel PN. The selective light transmission layer LBL and the light sensing array layer LSL together may constitute a fingerprint sensor FPS with the substrate SUB interposed therebetween.

[0113] The selective light-transmitting layer LBL may be implemented in various ways by using a material having low light transmittance and low reflectivity. In an example, the selective light-transmitting layer LBL may have low reflectivity (or high absorptivity) while blocking light (or rays), and may be implemented by using a material that maintains its hardness regardless of changes in temperature or humidity.

[0114] In an exemplary embodiment of the present invention, the display module DM and the selective light-transmitting layer LBL of the display panel PN may be arranged substantially parallel to each other. Therefore, light (or rays) EL from the plurality of light-emitting elements LD in the display module DM may be transmitted in the direction of the fingerprint located at the window WD, and reflected light RL reflected by the fingerprint may be transmitted to the selective light-transmitting layer LBL within a viewing angle θ formed by the pinhole PIH of the selective light-transmitting layer LBL.

[0115] The fingerprint sensor FPS can sense a fingerprint that is in contact with or in proximity to the display device DD. When a user's fingerprint is placed on the first surface SF1 of the display device DD, light EL emitted from the light-emitting element LD in the display module DM can become the light source to be transmitted to and reflected from the user's fingerprint. The reflected light RL can be transmitted through (or pass through) the display module DM and the substrate SUB, and can be transmitted through the pinholes PIH of the selective light-transmitting layer LBL to the light sensing array layer LSL.

[0116] The light sensing array layer LSL may include a plurality of light sensors PSR. Each light sensor PSR senses reflected light RL reflected by a different area of ​​the fingerprint and generates an electrical signal corresponding to the sensed reflected light RL. Each light sensor PSR may generate an electrical signal corresponding to the light reflected from the ridges of the fingerprint, or may generate an electrical signal corresponding to the light reflected from the valleys between the ridges. The amount of light (or intensity) sensed by the corresponding light sensor PSR may vary depending on the shape of the fingerprint from which the light is reflected, and may generate electrical signals with different levels depending on the amount of light sensed. That is, each electrical signal from the plurality of light sensors PSR may include brightness information (or image information). Whether the area corresponding to each light sensor PSR is a ridge or a valley can be determined by processing the electrical signal, and the entire image of the fingerprint can be arranged by combining the determined information.

[0117] The fingerprint area optically sampled in the display device DD can be defined. In an example, a plurality of fingerprint pixels FPXL can be defined corresponding to the plurality of light sensors PSR of the light sensing array layer LSL, and each fingerprint pixel FPXL can correspond to a subject region indicated by a pinhole PIH and a light sensor PSR. In an exemplary embodiment of the present invention, each fingerprint pixel FPXL can refer to a representative pixel PXL included in an area of ​​the sensing area SA, and the fingerprint of the user in the area is sensed when the user is in contact with or close to the sensing area SA. However, exemplary embodiments of the present invention are not limited thereto. In some exemplary embodiments, a plurality of pixels PXL included in an area of ​​the sensing area SA can form a group to constitute a corresponding fingerprint pixel FPXL.

[0118] The shape and size of the fingerprint pixel FPXL can be determined according to the distance O between the display panel PN and the selective light transmission layer LBL, the distance f between the selective light transmission layer LBL and the light sensing array layer LSL, the thickness T of the selective light transmission layer LBL, the diameter d and shape of each pinhole PIH, etc.

[0119] Each fingerprint pixel FPXL may include an area reflecting light that may have passed through a pinhole PIH, and the corresponding area may be defined as an optical sampling area OSA. Based on the optical sampling area OSA, a light sensing area LSA corresponding to the optical sampling area OSA may be defined in the light sensing array layer LSL. The light sensing area LSA corresponds to the optical sampling area OSA and may be an area in which reflected light RL from the optical sampling area OSA, after passing through a pinhole PIH, is incident on the light sensor PSR of the light sensing array layer LSL.

[0120] As described above, the optical fingerprint sensor FPS is easily implemented using some components included in the display device DD (e.g., the selective light transmission layer LBL and the light sensing array layer LSL), so that a large-area fingerprint sensor FPS capable of sensing the entire finger of a user can be implemented. In other words, a large-area fingerprint sensor FPS having a size (or area) larger than the size (or area) of the user's finger can be implemented.

[0121] 5A to 5D 1 is a plan view illustrating an exemplary embodiment of the arrangement of fingerprint pixels, pinholes, and light sensors constructed according to the principles of the present invention. Specifically, 5A to 5D is a plan view illustrating relative sizes, densities (or resolutions), and / or relative positions of fingerprint pixels FPXL, pinholes PIH, and light sensors PSR located in the sensing area SA according to various exemplary embodiments.

[0122] First, refer to Figure 5A , the sensing area SA may include pinholes PIH and light sensors PSR, each of which is smaller in number than the number of fingerprint pixels FPXL (PXL). For example, the pinholes PIH and light sensors PSR have a size smaller than that of the fingerprint pixels FPXL (PXL) and may be dispersed in the sensing area SA at a density lower than that of the fingerprint pixels FPXL (PXL).

[0123] Although FIG5 illustrates an embodiment in which the pinholes PIH and the light sensors PSR have a density lower than that of the fingerprint pixels FPXL (PXL), exemplary embodiments of the present invention are not limited thereto. In some exemplary embodiments, the pinholes PIH and the light sensors PSR may be dispersed in the sensing area SA to have substantially equal numbers and distances from each other, so as to correspond substantially one-to-one (1:1) with each other. In some examples, the pinholes PIH and the light sensors PSR may be arranged to overlap each other, forming a one-to-one (1:1) pair. In some exemplary embodiments, the pinholes PIH and the light sensors PSR forming a pair may be arranged to overlap any one of the fingerprint pixels FPXL (PXL) arranged in the sensing area SA, but exemplary embodiments of the present invention are not limited thereto. In some examples, the pinholes PIH and the light sensors PSR may be alternately arranged so as not to overlap each other, or may be arranged so as not to overlap the fingerprint pixels FPXL (PXL).

[0124] The pinhole PIH and the light sensor PSR may have sizes equal to or different from each other. That is, the relative sizes and densities of the pinhole PIH and the light sensor PSR are not particularly limited.

[0125] refer to Figure 5BThe sensing area SA may include a smaller number of pinholes PIH than the number of fingerprint pixels FPXL (FPXL) and a larger number of light sensors PSR than the number of fingerprint pixels FPXL (PXL). In this example, the pinholes PIH and the light sensors PSR may have a size smaller than that of the fingerprint pixels FPXL (PXL). The pinholes PIH may be dispersed in the sensing area SA at a density lower than that of the fingerprint pixels FPXL (PXL), and the light sensors PSR may be densely dispersed in the sensing area SA at a density higher than that of the fingerprint pixels FPXL (PXL).

[0126] At least some of the light sensors PSR may overlap with at least one pinhole PIH and / or at least one fingerprint pixel FPXL (PXL), but exemplary embodiments of the present invention are not limited thereto. In some exemplary embodiments, some light sensors PSR may be arranged to overlap with the pinhole PIH and / or the fingerprint pixel FPXL (PXL), while other light sensors PSR may be arranged in gaps between the fingerprint pixels FPXL (PXL).

[0127] refer to Figure 5C and Figure 5D , the light sensors PSR can be dispersed in the sensing area SA to have a ratio Figure 5B The size of the light sensor PSR in the embodiment shown in FIG is smaller than that of the light sensor PSR. Figure 5B The density of the light sensors PSR in the embodiment shown in FIG is high. In an example, the light sensors PSR may be dispersed in the sensing area SA at a distance of about 1 / 10 to about 1 / 100 of the distance between the pinholes PIH. Thus, the light sensors PSR are arranged densely enough in the sensing area SA so that there is no need for a one-to-one (1:1) alignment between the fingerprint pixels FPXL (PXL) and / or the pinholes PIH and the light sensors PSR, and therefore, the occurrence of moiré can be prevented or minimized regardless of how the fingerprint pixels FPXL (PXL) and / or the pinholes PIH are aligned with the light sensors PSR.

[0128] In some exemplary embodiments, the pinholes PIH may be dispersed in the sensing area SA at densities equal to or different from each other. Figure 5C As shown in , the pinholes PIH can be dispersed in the sensing area SA with a density equal to that of the fingerprint pixels FPXL (PXL), or as Figure 5D As shown in , the pinholes PIH may be dispersed in the sensing area SA at a density lower than that of the fingerprint pixels FPXL (PXL).

[0129] Despite 5A to 5D, the pinholes PIH and the light sensors PSR are arranged in a regular array in the sensing area SA, but the exemplary embodiments of the present invention are not limited thereto. In some exemplary embodiments, the pinholes PIH and / or the light sensors PSR may be irregularly dispersed in the sensing area SA, or may be dispersed with different densities or different arrangement structures for each area or interval of the sensing area SA.

[0130] The arrangement of the fingerprint pixels FPXL (PXL), pinholes PIH, and light sensors PSR is not limited to the above exemplary embodiments. For example, the shape, arrangement, relative size, number, density, and / or relative position of the fingerprint pixels FPXL (PXL), pinholes PIH, and / or light sensors PSR may be modified in various ways.

[0131] Figure 6 yes Figure 2 An enlarged cross-sectional view of the area EA is shown in FIG.

[0132] exist Figure 6 In the following, the components included in a representative pixel PXL will be described in more detail. Figure 2 The area EA shown in FIG (eg, the pixel circuit layer PCL and the display element layer DPL) will be described. In particular, at least one transistor TR provided in the pixel circuit layer PCL and the light emitting element LD (OLED) provided in the display element layer DPL will be described.

[0133] refer to Figures 1A to 6 , one representative pixel PXL (hereinafter referred to as “pixel”) may include a substrate SUB, a pixel circuit layer PCL provided on the substrate SUB, and a display element layer DPL provided on the pixel circuit layer PCL.

[0134] The pixel circuit layer PCL may include a buffer layer BFL, at least one transistor TR, and a protective layer PSV. The display element layer DPL may include a light-emitting element LD (OLED) that emits light. For ease of description, the pixel circuit layer PCL will be described first, followed by the display element layer DPL.

[0135] A buffer layer BFL may be provided on the substrate SUB. The buffer layer BFL may prevent impurities from diffusing into the transistor TR. The buffer layer BFL may be provided as a single layer, or may be provided as a multilayer layer including at least two layers. When the buffer layer BFL is provided as a multilayer layer, the layers may be formed of the same material or different materials. Depending on the material of the substrate SUB and / or process conditions, the buffer layer BFL may be omitted. The buffer layer BFL may be an inorganic insulating layer including an inorganic material or an organic insulating layer including an organic material.

[0136] The transistor TR may include a driving transistor electrically connected to the light emitting element LD (OLED) of the display element layer DPL to drive the light emitting element LD (OLED). The transistor TR may include a switching transistor for switching the driving transistor.

[0137] The transistor TR may include a semiconductor layer SCL, a gate electrode GE, a first terminal SE, and a second terminal DE. The first terminal SE may be any one of a source electrode and a drain electrode, and the second terminal DE may be another electrode. For example, when the first terminal SE is a source electrode, the second terminal DE may be a drain electrode.

[0138] The semiconductor layer SCL may be disposed on the buffer layer BFL. The semiconductor layer SCL may include a first region in contact with the first terminal SE and a second region in contact with the second terminal DE. The region between the first region and the second region may be a channel region. The semiconductor layer SCL may be a semiconductor pattern made of polycrystalline silicon, amorphous silicon, an oxide semiconductor, or the like. The channel region is a semiconductor pattern that is not doped with impurities and may be an intrinsic semiconductor. Each of the first region and the second region may be a semiconductor pattern doped with impurities.

[0139] The gate electrode GE may be provided on the semiconductor layer SCL with the gate insulating layer GI interposed therebetween. The gate insulating layer GI may be an inorganic insulating layer including an inorganic material.

[0140] The first terminal SE and the second terminal DE can be respectively in contact with the first region and the second region of the semiconductor layer SCL through a through hole penetrating the interlayer insulating layer ILD and the gate insulating layer GI. The interlayer insulating layer ILD can be an inorganic insulating layer including an inorganic material, but the exemplary embodiments of the present invention are not limited thereto. In some exemplary embodiments, the interlayer insulating layer ILD can be an organic insulating layer including an organic material.

[0141] Although the above embodiment describes a case where each of the first terminal SE and the second terminal DE of the transistor TR is electrically connected to a separate electrode of the semiconductor layer SCL, exemplary embodiments of the present invention are not limited thereto. In some exemplary embodiments, the first terminal SE of the transistor TR may be one of the first region and the second region adjacent to the channel region of the semiconductor layer SCL, and the second terminal DE of the transistor TR may be the other of the first region and the second region adjacent to the channel region of the semiconductor layer SCL. Therefore, the second terminal DE of the transistor TR may be electrically connected to the light-emitting element LD (OLED) of the display element layer DPL via a connection device including a bridge electrode or a contact electrode.

[0142] In an exemplary embodiment of the present invention, the transistor TR included in the pixel circuit layer PCL may be formed as an LTPS transistor, but the exemplary embodiments of the present invention are not limited thereto. In some exemplary embodiments, the transistor TR may be formed as an oxide semiconductor thin film transistor. In addition, in some exemplary embodiments, the pixel circuit layer PCL may include at least one transistor TR implemented by an LTPS thin film transistor and at least one transistor TR implemented by an oxide semiconductor thin film transistor. In addition, in the exemplary embodiment of the present invention, the case where the transistor TR is a thin film transistor with a top gate structure is described as an example, but the exemplary embodiments of the present invention are not limited thereto. In some exemplary embodiments, the transistor TR may be a thin film transistor with a bottom gate structure.

[0143] A protective layer PSV may be provided above the transistor TR. The protective layer PSV may be provided and / or formed above the transistor TR to cover the transistor TR. The protective layer PSV may be provided in the form of an organic insulating layer, an inorganic insulating layer, or an organic insulating layer disposed on an inorganic insulating layer. The inorganic insulating layer may include silicon oxide (SiO x ) and silicon nitride (SiN x ). The organic insulating layer may include an insulating material that allows light to transmit therethrough. For example, the organic insulating layer may include at least one of a photoresist, a polyacrylate resin, an epoxy resin, a phenolic resin, a polyamide resin, a polyimide resin, an unsaturated polyester resin, a polyphenylene ether resin, a polyphenylene sulfide resin, and a benzocyclobutene resin.

[0144] Next, the display element layer DPL will be described.

[0145] The display element layer DPL may include a light emitting element LD (OLED) provided on the protection layer PSV. The light emitting element LD (OLED) may include a first electrode AE, an emission layer EML, and a second electrode CE.

[0146] One of the first electrode AE ​​and the second electrode CE may be an anode electrode, and the other of the first electrode AE ​​and the second electrode CE may be a cathode electrode. For example, the first electrode AE ​​may be an anode electrode, and the second electrode CE may be a cathode electrode. When the light-emitting element LD (OLED) is a top-emission organic light-emitting element, the first electrode AE ​​may be a reflective electrode, and the second electrode CE may be a transmissive electrode. In the exemplary embodiment of the present invention, the case where the light-emitting element LD (OLED) is a top-emission organic light-emitting element and the first electrode AE ​​is an anode electrode is used as an example for description.

[0147] The first electrode AE ​​can be electrically connected to the transistor TR of the pixel circuit layer PCL via a contact hole CH penetrating the protective layer PSV. In an example, the first electrode AE ​​can be electrically connected to the second terminal DE of the transistor TR of the pixel circuit layer PCL via the contact hole CH of the protective layer PSV. The first electrode AE ​​may include a reflective layer capable of reflecting light and a transparent conductive layer disposed on top or bottom of the reflective layer. At least one of the transparent conductive layer and the reflective layer may be electrically connected to the transistor TR.

[0148] A pixel defining layer (PDL) may be further provided on the protective layer PSV, the pixel defining layer (PDL) having an opening (OPN) exposing a portion of the first electrode AE ​​(e.g., the upper surface of the first electrode AE). The pixel defining layer (PDL) may include an organic insulating layer. For example, the pixel defining layer (PDL) may include at least one of polystyrene, polymethyl methacrylate (PMMA), polyacrylonitrile (PAN), polyamide (PA), polyimide (PI), polyarylene ether (PAE), a heterocyclic polymer, parylene, epoxy resin, benzocyclobutene (BCB), a siloxane-based resin, and a silane-based resin.

[0149] The representative pixel PXL may be disposed in the pixel area PXA of the display area DA. In an exemplary embodiment of the present invention, the pixel area PXA may include an emission area EMA in which light is emitted from the light-emitting element LD (OLED) and a peripheral area adjacent to the emission area EMA. The peripheral area may be an area from which no light is emitted, and the emission area EMA may be an area having overlapping first electrodes AE, emission layers EML, and second electrodes CE. The emission area EMA may be defined as a portion of the first electrode AE ​​exposed through an opening OPN of the pixel defining layer PDL.

[0150] The emission layer (EML) may be disposed on the upper surface of the first electrode (AE) exposed through the opening (OPN) of the pixel defining layer (PDL). The emission layer (EML) may have a multilayer thin film structure including at least a light-generating layer. For example, the emission layer (EML) may include: a hole injection layer for injecting holes; a hole transport layer having excellent hole transport properties, which increases the chance of recombination between holes and electrons by suppressing the movement of electrons that fail to combine in the light-generating layer; a light-generating layer for emitting light through the recombination of injected electrons and holes; a hole blocking layer for suppressing the movement of holes that fail to combine in the light-generating layer; an electron transport layer for smoothly transporting electrons to the light-generating layer; and an electron injection layer for injecting electrons.

[0151] The color of the light generated in the light generating layer may be one of red, green, blue, and white, but exemplary embodiments of the present invention are not limited thereto. For example, the color of the light generated in the light generating layer may also be one of magenta, cyan, and yellow. The hole injection layer, hole transport layer, hole blocking layer, electron transport layer, and electron injection layer may be common layers connected in adjacent light emitting regions.

[0152] A thin film encapsulation TFE covering the second electrode CE may be provided over the second electrode CE.

[0153] The thin film encapsulation TFE encapsulates the display element layer DPL. The thin film encapsulation TFE may be provided as a single layer, but exemplary embodiments of the present invention are not limited thereto. In some exemplary embodiments, the thin film encapsulation TFE may be provided as a multilayer. The thin film encapsulation TFE may include a plurality of insulating layers covering the display element layer DPL including the light emitting element LD (OLED). The thin film encapsulation TFE may include at least one inorganic layer and at least one organic layer. For example, the thin film encapsulation TFE may have a structure in which inorganic layers and organic layers are alternately stacked. In some exemplary embodiments, the thin film encapsulation TFE may be an encapsulation substrate disposed on the display element layer DPL and bonded to the substrate SUB via a sealant.

[0154] A selective light transmission layer LBL may be provided between the substrate SUB and the pixel circuit layer PCL. The selective light transmission layer LBL may include a light blocking pattern LBP and at least one pinhole PIH. The pinhole PIH of the selective light transmission layer LBL may be located in the selective light transmission layer LBL to overlap with the emission area EMA of the representative pixel PXL, but exemplary embodiments of the present invention are not limited thereto.

[0155] Figure 7 is a schematic cross-sectional view of an exemplary embodiment of a display device. Figure 8 It is from Figure 7 An exemplary embodiment of a user fingerprint image captured by the light sensing array layer shown in FIG. 1 is illustrated in FIG. Figure 9 An image of a user's fingerprint in contact with a fingerprint contact surface of an exemplary embodiment of a display device is illustrated, including magnified images of a first region and a second region of the fingerprint. Figure 10 An image of a forged fingerprint in contact with a fingerprint contact surface of an exemplary embodiment of a display device is illustrated, including magnified images of a first region and a second region of the forged fingerprint.

[0156] refer to Figures 1A to 10When a user's fingerprint contacts the first surface SF1 of the sensing area SA of the display device DD, the light-emitting element LD (OLED) of each fingerprint pixel FPXL (PXL) corresponding to the contact area may be driven to emit light EL toward the first surface SF1. Hereinafter, for ease of description, the area of ​​the first surface SF1 of the sensing area SA that directly contacts the user's fingerprint is referred to as the fingerprint contact surface SF1.

[0157] The light-emitting elements LD (OLED) of the fingerprint pixels FPXL corresponding to the fingerprint contact surface SF1 can emit light EL simultaneously or sequentially. The light EL emitted toward the user's fingerprint can be reflected by the user's fingerprint, passing through (or transmitting through) the display module DM and the selective light-transmitting layer LBL, and then incident on the light sensing array layer LSL. The light sensors PSR of the light sensing array layer LSL acquire the user's fingerprint image by receiving the reflected light RL and provide the acquired fingerprint image to the fingerprint detector FPDP at a predetermined frame rate.

[0158] The light sensing array layer LSL can acquire a peripheral image of the user's fingerprint by receiving reflected light RL reflected from the peripheral portion of the user's fingerprint, and provide the acquired peripheral image to the fingerprint detector FPDP. In an exemplary embodiment of the present invention, the peripheral portion of the user's fingerprint may refer to an area B where the user's fingerprint is not in contact with the first surface SF1 but is spaced apart from (or adjacent to) the first surface SF1, as a region around the portion A (or fingerprint authentication portion) where the user's fingerprint contacts the fingerprint contact surface SF1 of the sensing area SA. Hereinafter, for ease of description, the portion A (or fingerprint authentication portion) where the user's fingerprint contacts the fingerprint contact surface SF1 is referred to as the "first area A," and the peripheral portion of the first area A is referred to as the "second area B."

[0159] The first region A of the user's fingerprint and the second region B of the user's fingerprint may include valleys located and continuously arranged between adjacent ridges, and each region may have a brightness difference (or grayscale difference) due to a difference between the reflected light RL incident on the light sensing array layer LSL. By using such a difference, the first region A of the user's fingerprint and the second region B of the user's fingerprint can be distinguished from each other in a fingerprint image acquired from the light sensing array layer LSL.

[0160] like Figure 7As shown in , when the selective light transmission layer LBL in the sensing area SA for sensing the user's fingerprint includes the first to fifth pinholes PIH1 to PIH5, the light sensing array layer LSL can obtain a fingerprint image of each unit pinhole PIH by receiving light that passes through the first to fifth pinholes PIH1 to PIH5, respectively, and then proceeds toward the light sensing array layer LSL. For example, when the first area A that is in direct contact with the user's finger and the second area B located at the peripheral portion of the first area A correspond to the first to fourth pinholes PIH1 to PIH4 of the selective light transmission layer LBL in the sensing area SA for fingerprint authentication, the light sensing array layer LSL can obtain a fingerprint image of each unit pinhole PIH by receiving light that passes through the first to fourth pinholes PIH1 to PIH4, respectively, and then proceeds toward the light sensing array layer LSL. Figure 8 Fingerprint image of each unit pinhole PIH shown in .

[0161] The light reflected from the first area A may pass through the first to fourth pinholes PIH1 to PIH4 and then proceed toward the light sensing array layer LSL corresponding to each of the first to fourth pinholes PIH1 to PIH4. Meanwhile, the light reflected from the second area B may pass through the first to fourth pinholes PIH1 to PIH4 and then proceed toward the light sensing array layer LSL corresponding to each of the first to fourth pinholes PIH1 to PIH4.

[0162] like Figure 8 As shown in , the amount (or intensity) of light reflected from the first area A and the amount (or intensity) of light reflected from the second area B can be different from each other. In this example, the amount (or intensity) of light reflected from the first area A can be greater than the amount (or intensity) of light reflected from the second area B. Because the first area A is the area where the user's fingerprint is in direct contact with the fingerprint contact surface SF1 and the second area B is the area where the user's fingerprint is not in contact with the fingerprint contact surface SF1, a difference in reflectivity between the ridges and valleys of the user's fingerprint will appear in each area. Due to these differences in reflectivity in the fingerprint image acquired from the light sensing array layer LSL, the first area A and the second area B of the user's fingerprint can be distinguished from each other.

[0163] The user's actual fingerprint or forged fingerprint can be brought into contact with the fingerprint contact surface SF1 of the display device DD. Forged fingerprints may include those printed on a transparent film or paper, those made by pouring a specific material into a fingerprint frame, and the like.

[0164] exist Figure 92 shows an example of a fingerprint image processed in the fingerprint detector FPDP when the fingerprint of the user's finger (hereinafter referred to as "biometric fingerprint") contacts the fingerprint contact surface SF1. As illustrated in the fingerprint image, it can be seen that ridges and valleys formed in the biometric fingerprint are observed in the first region A, and that ridges and valleys that are relatively darker than those in the first region A are observed in the second region B, but both have continuity with the ridges and valleys in the first region A.

[0165] exist Figure 10 , an example of a fingerprint image processed in the fingerprint detector FPDP when a forged fingerprint printed on paper contacts the fingerprint contact surface SF1 is shown in FIG. Figure 10 As illustrated in the fingerprint image shown in , it can be seen that a pattern having a shape similar to that of ridges and valleys formed in a biometric fingerprint is observed in the first region A, but an arrangement of pinholes PIH included in the selective light-transmitting layer LBL is observed in the second region B. In this example, the pinholes PIH forming a grid arrangement can be observed in the second region B.

[0166] As described above, while the ridges and valleys of the fingerprint can be observed in the first region A of each of the biometric fingerprint and the forged fingerprint, different images may be observed in the second region B of each of the biometric fingerprint and the forged fingerprint. That is, while the ridges and valleys of the fingerprint can be observed in the second region B of the biometric fingerprint even if they are dark, a grid arrangement of pinholes (PIH) may be observed in the second region B of the forged fingerprint. In an exemplary embodiment of the present invention, it is possible to determine whether the fingerprint in contact with the fingerprint contact surface SF1 is a biometric fingerprint or a forged fingerprint based on the image observed in the second region B of each of the biometric fingerprint and the forged fingerprint.

[0167] The fingerprint detector FPDP extracts an image corresponding to the first area A and an image corresponding to the second area B from the fingerprint image acquired from the light sensing array layer LSL, performs preprocessing or synthesis on the extracted images, and then determines the similarity of the images or determines whether the images correspond to the grid arrangement of the pinholes PIH, so as to determine whether the fingerprint in contact with the fingerprint contact surface SF1 of the display device DD is a biometric fingerprint or a forged fingerprint.

[0168] Figure 11 Yes Figure 1A and Figure 1B A block diagram schematically illustrates an exemplary embodiment of a fingerprint detector shown in FIG. Figure 12A Yes Figure 11 An image illustrating an exemplary biometric fingerprint image used in the similarity determination method performed in the similarity determiner shown in FIG. Figure 12B Yes Figure 11An image illustrating another exemplary biometric fingerprint image used in the similarity determination method performed in the similarity determiner shown in FIG.

[0169] refer to Figures 1A to 12B , the fingerprint detector FPDP may include an image receiver IRP, a database DBP, an image extractor IEP, an image processor IPP, a similarity determiner SDP and a fingerprint authentication execution unit FPAP.

[0170] The fingerprint detector FPDP can be formed integrally with the light sensing array layer LSL as a module, but can also be a separate device connected to the light sensing array layer LSL via a specific communication interface. For example, the fingerprint detector FPDP can be a processor or other computing device (or a partial configuration thereof) connected to the light sensing array layer LSL provided in module form via a universal serial bus (USB). Therefore, the light sensing array layer LSL can have a USB interface connected to the fingerprint detector FPDP.

[0171] The image receiver IRP can receive all images received from the light sensing array layer LSL at a predetermined frame rate and transmit the images to the image extractor IEP. In addition, the image receiver IRP can identify a fingerprint image obtained from the light sensing array layer LSL when the fingerprint contacts the fingerprint contact surface SF1 of the display device DD among the received images, store the fingerprint image in a buffer, and then transmit the fingerprint image to the image extractor IEP. The image receiver IRP can check whether an image among the received images is a fingerprint image by sensing changes in specific element values ​​(such as grayscale, brightness level, number of pixels, etc. whose values ​​have changed), store the image in a buffer when the image is determined to be a fingerprint image, and then transmit the image to the image extractor IEP.

[0172] The database DBP stores registered fingerprint images. The database DBP can store feature point information analyzed from registered fingerprint images. Because feature points vary from person to person, the database DBP can obtain registered fingerprint images from users, analyze the locations and number of feature points, compile the analyzed information into a database, and then store the database. Feature points can include endpoints where ridges in the registered fingerprint image pass through, and bifurcation points where two or more ridges meet.

[0173] The image extractor IEP can extract an image of a selected area from the fingerprint image transmitted by the image receiver IRP. The image extractor IEP can extract an image of a first area A used for fingerprint authentication and an image of a second area B which is a peripheral area of ​​the fingerprint by using a brightness difference (or grayscale difference) for each area caused by a difference between reflected lights in the fingerprint image transmitted from the image receiver IRP.

[0174] In the example, the image extractor IEP may choose to Figure 8 The first area A corresponding to the relatively bright area in the fingerprint image shown in FIG is used as a region of interest (ROI) to extract only the image of the corresponding area. Alternatively, the image extractor IEP may select Figure 8 The second area B corresponding to the relatively dark area in the fingerprint image shown in FIG is used as a region of interest (ROI) to extract only the image of the corresponding area. In some exemplary embodiments, the image extractor IEP may extract the image of the first area A and the image of the second area B by using an edge tracking algorithm, an edge detection algorithm, a boundary flow algorithm, etc. known in the art. The image extractor IEP may extract the image of the first area A for fingerprint authentication and the image of the second area B corresponding to the peripheral portion of the first area A from the fingerprint image transmitted from the image receiver IRP by using various methods known in the art.

[0175] The image of the first area A and the image of the second area B extracted from the image extractor IEP may be transmitted to the image processor IPP.

[0176] The image processor IPP may perform image preprocessing on the image of the first region A and the image of the second region B transmitted from the image extractor IEP. The image preprocessing may process the image of the first region A and the image of the second region B in a manner that allows for easy extraction of desired information by removing noise contained in the image of the first region A and the image of the second region B and reducing the amount of data. The image preprocessing may include smoothing, binarization, and thinning.

[0177] The image processor IPP may perform a smoothing process that increases brightness differentiation and removes noise so as to minimize the influence of noise on each of the image of the first region A and the image of the second region B. In an example, the smoothing process may be performed using a histogram and then using a median filter to perform smoothing to further remove fine noise. In addition, the image processor IPP may perform a binarization process for converting the image of the first region A and the image of the second region B to 0 (black) or 1 (white) (from which noise has been removed by the smoothing process) and then perform a thinning process. The image processor IPP may synthesize the image of the first region A and the image of the second region B on which the image preprocessing has been performed, and then transmit the synthesized image to the similarity determiner SDP.

[0178] The similarity determiner SDP may be in the form of one or more comparators that determine the degree of similarity between the first region A and the second region B using the image transmitted from the image processor IPP.

[0179] like Figure 12A As shown in , when there is a difference in brightness (or luminance) between the image of the first region A and the image of the second region B with respect to the boundary between the first region A and the second region B and the image of the first region A and the image of the second region B have patterns similar to or substantially the same as each other, the similarity determiner SDP can determine that the image of the first region A and the image of the second region B are images similar to each other. In an exemplary embodiment of the present invention, when the image of the first region A and the image of the second region B have patterns similar to or substantially the same as each other, this may refer to a case where the image of the first region A and the image of the second region B include ridges and valleys of a fingerprint having continuity. In addition, when there is a difference in brightness (or luminance) between the image of the first region A and the image of the second region B and the image of the first region A and the image of the second region B do not have patterns similar to or substantially the same as each other, the similarity determiner SDP can determine that the image of the first region A and the image of the second region B are images that are not similar to each other.

[0180] When it is determined that the image of the first area A and the image of the second area B are similar to each other (i.e., there is a light brightness (or brightness) difference between the image of the first area A and the image of the second area B and the image of the first area A and the image of the second area B include ridges and valleys of the fingerprint having continuity), the similarity determiner SDP can identify the fingerprint in contact with the fingerprint contact surface SF1 as a biometric fingerprint and transmit the result to the fingerprint authentication execution unit FPAP. The fingerprint authentication execution unit FPAP can perform fingerprint authentication by matching the image of the first area A with the registered fingerprint image transmitted from the database DBP.

[0181] In addition, when it is determined that the image of the first area A and the image of the second area B are not similar to each other (that is, there is a light brightness (or brightness) difference between the image of the first area A and the image of the second area B, but the image of the first area A and the image of the second area B do not include the ridges and valleys of the fingerprint having continuity), the similarity determiner SDP can identify the fingerprint in contact with the fingerprint contact surface SF1 as a forged fingerprint and transmit the result to the fingerprint authentication execution unit FPAP. The fingerprint authentication execution unit FPAP may not perform fingerprint authentication based on the result of the similarity determiner SDP.

[0182] In another embodiment, the similarity determiner SDP may determine the degree of similarity of the images by comparing the image transmitted from the image processor IPP with a registered reference image. The registered reference image may be Figure 12B, an image of a grid arrangement of pinholes PIH observed in the second area B of the forged fingerprint is shown in FIG. That is, in another embodiment, the similarity determiner SDP may determine whether the image transmitted from the image processor IPP corresponds to a reference image including a grid arrangement of pinholes PIH, and transmit the result to the fingerprint authentication execution unit FPAP.

[0183] When the image transmitted from the image processor IPP does not correspond to the reference image of the grid arrangement including the pinholes PIH, the similarity determiner SDP may identify the fingerprint in contact with the fingerprint contact surface SF1 as a biometric fingerprint and transmit the result to the fingerprint authentication execution unit FPAP. The fingerprint authentication execution unit FPAP may perform fingerprint authentication by matching the image of the first area A with the registered reference image transmitted from the database DBP. In addition, when the image transmitted from the image processor IPP corresponds to the reference image of the grid arrangement including the pinholes PIH, the similarity determiner SDP may identify the fingerprint in contact with the fingerprint contact surface SF1 as a forged fingerprint and transmit the result to the fingerprint authentication execution unit FPAP. The fingerprint authentication execution unit FPAP may not perform fingerprint authentication based on the result of the similarity determiner SDP.

[0184] As described above, according to exemplary embodiments of the present invention, the light sensing array layer LSL including the light sensors PSR and the selective light transmission layer LBL including the pinholes PIH constitute a fingerprint sensor FPS, allowing the fingerprint sensor FPS to be implemented over a large area. When using a large-area fingerprint sensor FPS, the fingerprint sensor FPS can acquire an image of the user's entire fingerprint. Thus, the fingerprint sensor FPS can acquire an image of not only the first area A of the fingerprint in contact with the fingerprint contact surface SF1, but also the second area B, which is the peripheral portion of the first area A. The fingerprint sensor FPS determines the degree of similarity by analyzing only the images of the first area A and the second area B to determine whether the fingerprint in contact with the fingerprint contact surface SF1 is a biometric fingerprint or a forged fingerprint.

[0185] Therefore, the display device according to an exemplary embodiment of the present invention can easily determine whether the fingerprint in contact with the fingerprint contact surface SF1 is a forged fingerprint without having to include a separate biometric sensor for determining whether the fingerprint is a biometric fingerprint. In addition, the display device according to an exemplary embodiment of the present invention can easily determine whether the fingerprint in contact with the fingerprint contact surface SF1 is a forged fingerprint without having to include a sensor (e.g., a color sensor) for determining whether the fingerprint is a forged fingerprint by using the color characteristics of light reflected from the fingerprint. In addition, the display device according to an exemplary embodiment of the present invention can reduce the manufacturing costs incurred compared to when a separate biometric sensor and / or a separate color sensor is required.

[0186] In the following, reference will be made to Figure 13 and Figure 14 ,based on Figure 11 The fingerprint authentication method of the present invention is described based on the operation of the fingerprint detector FPDP shown in FIG.

[0187] Figure 13 According to the principle of the present invention Figure 11 Flowchart illustrating an exemplary fingerprint authentication method of the fingerprint sensor shown in FIG.

[0188] refer to Figures 1A to 13 , the first step is to determine whether the fingerprint has come into contact with the fingerprint contact surface SF1 (step S10).

[0189] When the contact is recognized as a fingerprint identification contact, the fingerprint pixel FPXL (PXL) is driven to turn on the light-emitting element LD (OLED) included in the fingerprint pixel FPXL (PXL) corresponding to the fingerprint contact surface SF1, thereby emitting light toward the fingerprint contact surface SF1. Light reflected from the fingerprint contacting the fingerprint contact surface SF1 then passes through the pinhole PIH and is received by the light sensor PSR of the light sensing array layer LSL. The light sensor PSR converts the received light into an electrical signal to acquire a fingerprint image (step S20).

[0190] The acquired fingerprint image is transmitted to the image extractor IEP through the image receiver IRP. The image extractor IEP extracts an image of an area (first area A) of the fingerprint in contact with the fingerprint contact surface SF1 and an image of the peripheral portion (second area B) of an area of ​​the fingerprint (step S30).

[0191] The image extracted from the image extractor IEP is transmitted to the image processor IPP. The image processor IPP performs image preprocessing on the extracted image and synthesizes the image (step S40).

[0192] The image, on which image pre-processing has been performed, is transmitted to the similarity determiner SDP, and the similarity determiner SDP determines the similarity of the images (step S50). When the similarity determiner SDP determines that the image of the first region A and the image of the second region B are similar to each other relative to the composite image, the fingerprint in contact with the fingerprint contact surface SF1 is determined to be a biometric fingerprint (step S60). Therefore, the fingerprint authentication execution unit FPAP performs fingerprint authentication processing (step S70). On the other hand, when the similarity determiner SDP determines that the image of the first region A and the image of the second region B are not similar to each other relative to the composite image, the fingerprint in contact with the fingerprint contact surface SF1 is determined to be a forged fingerprint, and therefore the fingerprint authentication processing is not performed (step S80).

[0193] Figure 14 According to the principle of the present invention Figure 11 Flowchart illustrating another exemplary fingerprint authentication method of the fingerprint sensor shown in FIG. Figure 14 Steps S10 to S40 shown in FIG. Figure 13 Steps S10 to S40 shown in FIG. 5 are the same, and thus description thereof will be omitted to avoid redundancy.

[0194] refer to Figures 1A to 11 、 Figure 12B and Figure 14 The image on which image pre-processing has been performed is transmitted to the similarity determiner SDP, and it is determined whether the image corresponds to the reference image (step S150). When the similarity determiner SDP determines that the image corresponding to the second area B among the images corresponds to the reference image, the fingerprint in contact with the fingerprint contact surface SF1 is determined to be a forged fingerprint (step S160). In an exemplary embodiment of the present invention, the reference image may be an image including a grid arrangement of pinholes PIH.

[0195] In addition, when the similarity determiner SDP determines that the image corresponding to the second area B among the images does not correspond to the reference image, the fingerprint in contact with the fingerprint contact surface SF1 is determined to be a biometric fingerprint (step S170). Therefore, the fingerprint authentication execution unit FPAP performs fingerprint authentication processing (step S180).

[0196] An exemplary embodiment of the present invention provides a display device including a fingerprint sensor and a fingerprint authentication method to simultaneously acquire a first image for fingerprint authentication and a peripheral portion of a fingerprint in contact with a fingerprint contact surface (e.g., an area where the fingerprint is not in contact with the fingerprint contact surface) by sensing light reflected by the fingerprint and determine the similarity between the first image and the second image, thereby easily determining whether the fingerprint is a forged fingerprint.

[0197] Although certain exemplary embodiments and implementations have been described herein, other embodiments and modifications will be apparent from the description. Therefore, the inventive concept is not limited to these embodiments, but rather to the broader scope of the appended claims and various obvious modifications and equivalent arrangements as will be apparent to those skilled in the art.

Claims

1. A display device, wherein: The display device includes: A fingerprint sensor comprising a first layer having at least one light sensor to generate a fingerprint image corresponding to light reflected from a fingerprint contact surface, a light emitting element to transmit light reflected from the fingerprint, and a second layer including a pinhole to allow the reflected light to be incident on the at least one light sensor; a fingerprint detector that receives the fingerprint image from the fingerprint sensor, extracts a first image corresponding to a first area of ​​the fingerprint and a second image corresponding to a second area of ​​the fingerprint, compares the first image and the second image to determine similarity, and performs fingerprint authentication based on the similarity determination, wherein The first area of ​​the fingerprint is in contact with the fingerprint contact surface, and the second area of ​​the fingerprint is not in contact with the fingerprint contact surface, Wherein, the fingerprint detector comprises: a fingerprint image extractor, receiving the fingerprint image from the first layer to extract the first image and the second image; an image processor, performing preprocessing on the extracted first image and second image; a comparator that determines similarity by comparing the preprocessed first image and the preprocessed second image; and an authentication unit that authenticates the fingerprint based on the determination of the comparator, and wherein the comparator is configured to determine the similarity of the patterns of the preprocessed first image and the preprocessed second image by analyzing continuity of at least one of valleys and ridges of the preprocessed second image with at least one of valleys and ridges of the preprocessed first image, The comparator is configured to determine whether the fingerprint is a biometric fingerprint and whether the preprocessed first image and the preprocessed second image have similar patterns by comparing the brightness of the preprocessed first image with the brightness of the preprocessed second image.

2. The display device according to claim 1, wherein When the brightness of the preprocessed first image and the brightness of the preprocessed second image are different from each other and the preprocessed first image and the preprocessed second image have the similar patterns, the comparator is configured to determine that the fingerprint is a biometric fingerprint.

3. The display device according to claim 1, wherein When the brightness of the preprocessed first image and the brightness of the preprocessed second image are different and the preprocessed first image and the preprocessed second image do not have the similar pattern, the comparator is configured to determine that the fingerprint is forged.

4. The display device according to claim 3, wherein The fingerprint image extractor is configured to extract the first image and the second image by differentiating an amount of light reflected in the first area of ​​the fingerprint from an amount of light reflected in the second area of ​​the fingerprint.

5. The display device according to claim 1, wherein The first layer includes a light sensing array layer, and the second layer includes a selective light transmitting layer having a light blocking pattern located between the pinholes, and wherein the pinholes are configured to focus light emitted from corresponding light emitting elements and subsequently reflected from the fingerprint. The display device according to claim 5 , wherein: The pinholes comprise an array.

7. The display device according to claim 6, wherein: The fingerprint detector comprises: a fingerprint image extractor, receiving the fingerprint image from the light sensing array layer to extract the first image and the second image; an image processor, configured to preprocess the extracted first image and second image and synthesize the first image and the second image; a comparator that determines whether the second image in the composite image from the image processor includes the array; and An authentication unit authenticates the fingerprint based on the determination of the comparator.

8. The display device according to claim 7, wherein: When the second image includes the array, the comparator is configured to determine that the fingerprint image is forged.

9. The display device according to claim 8, wherein When the second image does not include the array, the comparator is configured to determine that the fingerprint image is a biometric fingerprint.

10. The display device according to claim 1, wherein The second region is located at the periphery of the first region.

11. The display device according to claim 9, wherein The array comprises a grid arrangement.

12. The display device according to claim 1, wherein The comparator includes a similarity determiner configured to determine similar patterns by analyzing continuity of valleys and ridges of the pre-processed second image with valleys and ridges of the pre-processed first image.

13. A method for authenticating a fingerprint, for use in a display device having a fingerprint sensor, wherein: The method comprises the steps of: receiving a fingerprint image corresponding to a fingerprint of a user in contact with the fingerprint contact surface by sensing light reflected from the fingerprint; extracting, from the fingerprint image, a first image corresponding to a first area of ​​the fingerprint in contact with the fingerprint contact surface, and a second image corresponding to a second area of ​​the fingerprint located at a periphery of the first area of ​​the fingerprint; performing image preprocessing on the extracted first image and the second image; comparing the pre-processed first image and the pre-processed second image to determine similarity; and authenticating the fingerprint based on a similarity determined from a comparison of the pre-processed first image and the pre-processed second image, Wherein, when the preprocessed first image and the preprocessed second image have valleys and ridges that are continuous with each other, the first image and the second image have similar patterns.

14. The method according to claim 13, wherein The method further includes the step of determining that the fingerprint is a biometric fingerprint by using the brightness of the preprocessed first image and the brightness of the preprocessed second image to determine that the preprocessed first image and the preprocessed second image have similar patterns.

15. The method according to claim 14, wherein The method further includes the step of determining that the fingerprint is a biometric fingerprint when the brightness of the first image and the second image are different from each other and the first image and the second image have similar patterns.

16. The method according to claim 15, wherein The method further includes the step of determining that the fingerprint is forged when the brightness of the first image and the second image are different from each other and the first image and the second image do not have similar patterns.

17. The method according to claim 13, wherein: The fingerprint sensor includes: a first layer including at least one light sensor to sense light reflected by the fingerprint; and a second layer including pinholes arranged in an array to transmit incident light to the light sensor. And, the method further comprises the step of: when the second image includes the array, determining that the fingerprint is a forged fingerprint.

18. The method according to claim 17, wherein: The method further comprises the step of determining that the fingerprint is a biometric fingerprint when the pre-processed second image does not include the array.

19. A fingerprint detector in a display device, which distinguishes biological fingerprints from forged fingerprints, wherein: The fingerprint detector comprises: a fingerprint image extractor receiving the fingerprint image from the light sensing array layer to extract a first image corresponding to a first area of ​​the fingerprint image of the fingerprint in contact with the fingerprint contact surface and a second image corresponding to a second area of ​​the fingerprint image not in contact with the fingerprint contact surface; an image processor, performing preprocessing on the extracted first image and second image; a comparator, for comparing the preprocessed first image and the preprocessed second image; an authentication unit that authenticates the fingerprint based on the determination of the comparator; and The comparator is configured to determine the similarity of the patterns of the preprocessed first image and the preprocessed second image by analyzing the continuity of at least one of the valleys and ridges of the preprocessed second image with at least one of the valleys and ridges of the preprocessed first image.

20. The fingerprint detector according to claim 19, wherein The second area of ​​the fingerprint image is located at the periphery of the fingerprint.

Images