Display device

Abstract

A display device includes a window on which a fingerprint detection area is defined in which fingerprint information is detected, an optical layer disposed below the window and in which at least one transmission hole overlapping the fingerprint detection area is defined, a protective layer disposed below the optical layer, and a sensor. A refractive index of the protective layer is greater than a refractive index of the window. A distance from the optical layer to the window is less than a distance from the optical layer to the sensor.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2020-0107996, filed with the Korean Intellectual Property Office on August 26, 2020, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] Embodiments of the present invention relate to a flexible display device that performs folding and unfolding operations about a folding axis, and includes a sensor for detecting fingerprint information of a user that can be used for fingerprint authentication. Background Technology

[0004] Electronic products such as smartphones, digital cameras, laptops, navigation systems, and smart TVs include display devices for displaying images to users. The display device generates images and provides them to the user as displayed on the screen.

[0005] With advancements in display technology, various types of display devices have been developed in recent years. A typical example of such devices is flexible display devices that are bendable, foldable, or rollable. The ability to deform into various shapes allows for increased portability and user convenience.

[0006] A foldable display device is a type of flexible display device that can be folded about a folding axis extending in one direction. A foldable display device may include a flexible display panel and a flexible window arranged on the flexible display panel.

[0007] Display devices offer a variety of functions that enable users to interact with them. For example, a display device can display images to provide information to the user, and / or can detect user input. Some display devices may also have the ability to detect fingerprint information of a user that can be used for fingerprint authentication. Optical fingerprint sensors can detect incident light to detect fingerprint information. Summary of the Invention

[0008] Embodiments of the present invention provide a foldable display device that has increased reliability and efficiency in detecting fingerprint authentication information.

[0009] According to an embodiment of the present invention, a display device includes: a window defining a fingerprint detection area thereon for detecting fingerprint information in the fingerprint detection area; an optical layer disposed below the window and defining at least one transmission hole overlapping the fingerprint detection area in the optical layer; a protective layer disposed below the optical layer; and a sensor. The refractive index of the protective layer is greater than the refractive index of the window. The distance from the optical layer to the window is less than the distance from the optical layer to the sensor.

[0010] In an embodiment, multiple transmission holes may be provided. When viewed in a plan view, the multiple transmission holes may be spaced apart from each other in a first direction or in a second direction intersecting the first direction.

[0011] According to an embodiment of the present invention, a display device includes: an upper layer having a fingerprint detection area disposed on a top surface of the upper layer. The fingerprint detection area receives light indicating fingerprint information. The display device further includes: an optical layer disposed below the upper layer and having a plurality of transmission holes, through which light penetrating the upper layer passes; a lower layer disposed below the optical layer, on which light passing through the plurality of transmission holes is received and passes; and a sensor. The refractive index of the lower layer is greater than that of the upper layer. The sensor is disposed below the lower layer and overlaps with the fingerprint detection area. The sensor receives light passing through the lower layer. The thickness of the lower layer is greater than that of the upper layer.

[0012] According to an embodiment of the present invention, a display device includes: a display module including a first non-folding area, a second non-folding area including a fingerprint detection area, and a folding area disposed between the first non-folding area and the second non-folding area, wherein fingerprint information is detected in the fingerprint detection area. The folding area is foldable about a folding axis. The display device further includes: a support plate disposed below the display module and defining an opening in the support plate overlapping the fingerprint detection area; a sensor disposed below the support plate and overlapping the opening; and a protective layer disposed between the display module and the support plate. The refractive index of the protective layer is greater than that of the display module. Attached Figure Description

[0013] The above and other features of the present invention will become more apparent from the detailed description of embodiments thereof with reference to the accompanying drawings.

[0014] Figure 1 The figure shows a perspective view of a display device according to an embodiment of the present invention.

[0015] Figure 2 The diagram shows... Figure 1 The image depicts a perspective view of the display device in its folded state.

[0016] Figure 3 The diagram shows along Figure 1 The cross-sectional view taken from line I-I'.

[0017] Figure 4 The diagram shows... Figure 3 A cross-sectional view of the display panel.

[0018] Figure 5 The diagram shows further details. Figure 4 A cross-sectional view of the display panel.

[0019] Figure 6 The diagram shows the relationship between Figure 3 A perspective view of the overlapping window, optical layer, and sensor of the fingerprint detection area.

[0020] Figure 7 The diagram shows along Figure 6 The cross-sectional view taken from line II-II'.

[0021] Figure 8 The diagram shows the incident light. Figure 6 A cross-sectional view of the path of light from the first zone to the second zone.

[0022] Figure 9 and Figure 10 The figure shows a cross-sectional view of a display device according to an embodiment of the present invention.

[0023] Figure 11 The figure shows a cross-sectional view of a display device according to an embodiment of the present invention. Detailed Implementation

[0024] Embodiments of the invention will be described more fully below with reference to the accompanying drawings. Throughout the drawings, the same reference numerals may refer to the same elements.

[0025] It will be understood that when a component, such as a membrane, region, layer, or element, is referred to as being "on," "connected to," "coupled to," or "adjacent to" another component, it can be directly on, connected to, coupled to, or adjacent to the other component, or there may be intermediary components. It will also be understood that when a component is referred to as being "between" two components, it can be the only component between the two components, or there may be one or more intermediary components. It will also be understood that when a component is referred to as "covering" another component, it can be the only component covering the other component, or one or more intermediary components may also cover the other component. Other terms used to describe relationships between components should be interpreted in a similar manner.

[0026] The term "and / or" includes one or more combinations defined by the associated components.

[0027] It will be understood that the terms “first,” “second,” “third,” etc., are used herein to distinguish one element from another, and these elements are not limited by these terms. Thus, a “first” element in one embodiment may be described as a “second” element in another embodiment.

[0028] Unless the context clearly indicates otherwise, the singular form is intended to include the plural form as well.

[0029] For ease of description, spatial relative terms such as “below,” “under,” “lower,” “down,” “above,” and “upper” are used herein to describe the relationship between one element or feature and another element or feature as illustrated in the accompanying drawings. It will be understood that, in addition to the orientation depicted in the drawings, the spatial relative terms are also intended to cover different orientations of the device in use or operation. For example, if the device in the drawings is flipped, an element described as “below,” “under,” or “down” of other elements or features will consequently be oriented “above” of those elements or features. Thus, the exemplary terms “below” and “down” can encompass both the above and below orientations.

[0030] It should be understood that the terms “comprising,” “including,” and “having,” etc., are used to specify the presence of the stated features, wholes, steps, operations, components, elements, or combinations thereof, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, components, elements, or combinations thereof.

[0031] It should be understood that the description of features or aspects within each embodiment should generally be considered as other similar features or aspects that may be used in other embodiments, unless the context clearly indicates otherwise.

[0032] In this document, when two or more elements or values ​​are described as substantially the same or approximately equal to each other, it should be understood that the elements or values ​​are the same, the elements or values ​​are equal to each other within measurement error, or, if measurably unequal, the elements or values ​​are sufficiently close in value to be functionally equal to each other, as will be understood by one of ordinary skill in the art. For example, taking into account the errors and problematic measurements associated with the measurement of a particular quantity (i.e., the limitations of the measurement system), the term “about” as used herein includes stated values ​​and averages within an acceptable range of deviation for a particular value as determined by one of ordinary skill in the art. For example, “about” can mean within one or more standard deviations as understood by one of ordinary skill in the art. Furthermore, it should be understood that while a parameter may be described herein as having “about” a certain value, according to embodiments, as will be understood by one of ordinary skill in the art, the parameter may be an exact value or an approximate value within measurement error. Other uses of these terms and similar terms to describe relationships between components should be interpreted in a similar manner.

[0033] Figure 1 The figure shows a perspective view of a display device according to an embodiment of the present invention. Figure 2 The diagram shows... Figure 1 The image depicts a perspective view of the display device in its folded state.

[0034] Reference Figure 1According to an embodiment of the present invention, the display device DD may have sides extending in a first direction DR1 and a second direction DR2 intersecting the first direction DR1. Compared to the first direction DR1 or the second direction DR2, the display device DD may have a smaller thickness in the third direction DR3.

[0035] The third direction DR3 is defined herein as the direction that intersects substantially perpendicularly with the plane formed by the first direction DR1 and the second direction DR2. In this specification, the phrase "when viewed in a plan view" can mean "when viewed in the third direction DR3".

[0036] When viewed in a plan view, the display device DD may have a rectangular shape. However, the invention is not limited thereto. For example, according to an embodiment, the display device DD may have a circular shape, a polygonal shape, or any other various shapes.

[0037] The display device DD may have a top surface defined as a display surface DS, and may have a plane defined by a first direction DR1 and a second direction DR2. The display surface DS may provide a user with at least one image IM generated by the display device DD.

[0038] The display surface DS may include a display area DA and a non-display area NDA surrounding the display area DA. The display area DA may display at least one image IM, and at least one image IM may not be displayed in the non-display area NDA. The non-display area NDA may surround the display area DA and may provide the display device DD with an edge printed with a specific color. For example, the non-display area NDA may provide the display device DD with a border of a specific color that surrounds the display area DA.

[0039] According to an embodiment of the present invention, the display device DD may be a foldable display device. For example, the display device DD may include a first non-foldable region NFA1, a second non-foldable region NFA2, and a foldable region FA disposed between the first non-foldable region NFA1 and the second non-foldable region NFA2. The first non-foldable region NFA1, the foldable region FA, and the second non-foldable region NFA2 may be disposed on a first direction DR1.

[0040] Reference Figure 2 The display device DD can be folded around a folding axis FX extending in the second direction DR2. When the display device DD is folded around the folding axis FX, the top surfaces of the first non-folding region NFA1 and the second non-folding region NFA2 can face each other. That is, the display device DD can be folded inward to avoid exposing the display surface DS to the outside, thereby protecting the display surface DS when the display device DD is folded. This folding scheme can be referred to as inward folding.

[0041] In the embodiments, as described above, the display device DD is foldable about a folding axis FX extending in the second direction DR2. However, embodiments of the invention are not limited thereto. For example, according to embodiments, the display device DD can be foldable in different ways. For example, the display device DD can be folded about a folding axis extending in the first direction DR1. Alternatively, the display device DD can be folded outward about the folding axis FX such that the top surfaces of the first non-folding region NFA1 and the second non-folding region NFA2 do not face each other. This folding scheme can be referred to as outward folding.

[0042] Return to reference Figure 1 The display device DD may include a fingerprint detection area FDA. For example, when a user places their finger on the fingerprint detection area FDA, the display device DD can detect the user's fingerprint and use the detected fingerprint information for authentication.

[0043] According to embodiments of the present invention, the fingerprint detection area FDA can be defined within the second non-folded area NFA2. However, there are no restrictions on the location of the fingerprint detection area FDA. For example, according to an embodiment, the fingerprint detection area FDA can be defined within any area of ​​the display surface DS.

[0044] Figure 3 The diagram shows along Figure 1 The cross-sectional view taken from line I-I'. Figure 4 The diagram shows... Figure 3 A cross-sectional view of the display panel. Figure 5 The diagram shows further details. Figure 4 A cross-sectional view of the display panel.

[0045] Reference Figure 3 The display device DD may include a display module DM, a protective layer PF disposed below the display module DM, a support plate SP disposed below the protective layer PF, and a sensor SS disposed below the support plate SP. The protective layer PF may include a first protective layer PF1 and a second protective layer PF2, which will be described in further detail below. The support plate SP may include an opening OP and a filling member RS, which will be described in further detail below.

[0046] The display module DM can generate images, such as at least one image IM, and can provide the generated images to the user. The display module DM may include, for example, a window WIN, an anti-reflective layer RPL, an input sensing part ISP, and a display panel DP.

[0047] The window (WIN) protects the display panel (DP) from external impacts such as scratches. Images generated by the display panel (DP) (e.g., at least one image IM) can pass through the window WIN and then be provided to the user. Therefore, the window WIN can be optically transparent. For example, the window WIN can comprise glass. However, there are no limitations on the material of the window WIN. For example, according to an embodiment, the window WIN can comprise transparent plastic. The window WIN can have a small thickness and therefore can be easily folded.

[0048] According to an embodiment of the present invention, Figure 1 The fingerprint detection area FDA can be substantially confined to the top surface of the window WIN. For example, in an embodiment, the fingerprint detection area FDA, which can detect the user's fingerprint information, can be confined to the window WIN.

[0049] An anti-reflective layer RPL can be disposed below the window WIN. In an embodiment, the anti-reflective layer RPL can be a film that prevents the reflection of external light. The anti-reflective layer RPL can reduce the reflectivity of external light incident on the display panel DP from outside the display device DD. The anti-reflective layer RPL may include one or more of, for example, a retarder and a polarizer.

[0050] However, the anti-reflective layer RPL is not limited to the configuration described above. For example, according to an embodiment, the anti-reflective layer RPL can be implemented using multiple color filters and a black matrix.

[0051] The input sensing section (ISP) can be positioned beneath the anti-reflective layer (RPL). The ISP may include multiple sensors for detecting external inputs. These sensors may use capacitive methods to detect external inputs. External inputs may include, for example, a user's body part such as a finger, light, heat, a pen, pressure, or various other types of external inputs. The display panel (DP) can be positioned beneath the ISP. The display panel (DP) may include light-emitting elements. (Refer to the following...) Figure 4 The structure of the display panel DP according to an embodiment of the present invention will be described in further detail.

[0052] Reference Figure 4 The display panel DP may include a substrate SUB, an optical layer OPL disposed on the substrate SUB, a circuit element layer CL disposed on the optical layer OPL, a display element layer OL disposed on the circuit element layer CL, and a thin film encapsulation layer TFE disposed on the display element layer OL. The circuit element layer CL and the display element layer OL may form a pixel layer PXL.

[0053] The substrate SUB may include a display area DA and a non-display area NDA surrounding the display area DA. The substrate SUB may include a flexible plastic material.

[0054] The optical layer OPL can be disposed on the substrate SUB. However, there are no restrictions on the location of the optical layer OPL. For example, according to embodiments of the present invention, the optical layer OPL can be disposed at different locations in the display panel DP.

[0055] The optical layer (OPL) can reflect or absorb external light incident on the display panel (DP). For example, the OPL may include a metallic material that reflects external light. Alternatively, the OPL may have a light-absorbing color (e.g., black) that absorbs external light.

[0056] The optical layer OPL can prevent the identification of components disposed beneath the substrate SUB. For example, when a user is viewing an image (e.g., at least one image IM) on a display device DD, the optical layer OPL can prevent the user from visually identifying components disposed beneath the substrate SUB. The optical layer OPL can control external light to allow external light to pass through only specific areas of the substrate SUB. This will be described further below.

[0057] The pixel layer PXL, which includes the circuit element layer CL and the display element layer OL arranged on the circuit element layer CL, can be arranged on the optical layer OPL.

[0058] Reference Figure 4 and Figure 5 The circuit element layer CL may include a buffer layer BFL, a first transistor T1, a second transistor T2, and first to sixth dielectric layers 10, 20, 30, 40, 50 and 60.

[0059] The buffer layer BFL can be disposed on the optical layer OPL. The buffer layer BFL can increase the adhesion between the substrate SUB and the semiconductor pattern.

[0060] A first transistor T1 and a second transistor T2 can be disposed on a buffer layer BFL. The first transistor T1 may include a source S1, an active A1, and a drain D1 formed by a semiconductor pattern, and the second transistor T2 may include a source S2, an active A2, and a drain D2 formed by a semiconductor pattern. That is, each of the first transistor T1 and the second transistor T2 may include a source region, an active region, and a drain region. When viewed in cross-section, the source S1 and drain D1 may extend from the active A1 in opposite directions, and the source S2 and drain D2 may extend from the active A2 in opposite directions. When viewed in plan view, a connection signal line SCL formed by the semiconductor pattern can be connected to the drain D2 of the second transistor T2.

[0061] The first dielectric layer 10 can be disposed on the buffer layer BFL, and gates G1 and G2 can be disposed on the first dielectric layer 10. Gates G1 and G2 can each be part of a metal pattern. Gates G1 and G2 can overlap with actives A1 and A2, respectively.

[0062] A first dielectric layer 10 and a second dielectric layer 20 may be disposed on the source S1, drain D1, and active A1 of the first transistor T1, and on the source S2, drain D2, and active A2 of the second transistor T2. The second dielectric layer 20 may cover the gates G1 and G2. Referring to the second transistor T2, an upper electrode UE may be disposed on the second dielectric layer 20. The upper electrode UE may overlap with the gate G2 of the second transistor T2. The upper electrode UE may be part of a metal pattern. A portion of the gate G2 and the upper electrode UE covering it may define a capacitor. In embodiments of the present invention, the upper electrode UE may be omitted.

[0063] A second dielectric layer 20 and a third dielectric layer 30 covering the top electrode UE can be provided on gates G1 and G2. A first connection electrode CNE1 can be disposed on the third dielectric layer 30. The first connection electrode CNE1 can be coupled to the connection signal line SCL through a contact hole CNT-1 that penetrates from the first dielectric layer 10 to the third dielectric layer 30.

[0064] A fourth dielectric layer 40 can be disposed on the third dielectric layer 30. A fifth dielectric layer 50 can be disposed on the fourth dielectric layer 40. The fifth dielectric layer 50 can be an organic layer. A second connection electrode CNE2 can be disposed on the fifth dielectric layer 50. The second connection electrode CNE2 can be coupled to the first connection electrode CNE1 through a contact hole CNT-2 penetrating the fourth dielectric layer 40 and the fifth dielectric layer 50. The fifth dielectric layer 50 and a sixth dielectric layer 60 covering the second connection electrode CNE2 can be disposed on the fourth dielectric layer 40. The sixth dielectric layer 60 can be an organic layer.

[0065] The display element layer OL can be disposed on the circuit element layer CL. For example, the display element layer OL can be connected to the circuit element layer CL. The display element layer OL may include a pixel defining layer PDL and a light-emitting element OLED.

[0066] The pixel defining layer (PDL) can be disposed on the circuit element layer (CL). For example, the pixel defining layer (PDL) can be disposed on the sixth dielectric layer (60). The pixel aperture (PX-OP) can be defined in the pixel defining layer (PDL). The light-emitting element (OLED) can be disposed in the pixel aperture (PX-OP) defined in the pixel defining layer (PDL).

[0067] An OLED light-emitting element may include a first electrode AE, a hole control layer HCL, an emitter layer EML, an electron control layer ECL, and a second electrode CE.

[0068] A first electrode AE ​​can be disposed on a sixth dielectric layer 60. The first electrode AE ​​can be connected to a second connection electrode CNE2 through a contact hole CNT-3 penetrating the sixth dielectric layer 60. At least a portion of the first electrode AE ​​can be exposed to the pixel opening PX-OP of the pixel defining layer PDL. The first electrode AE ​​can reflect light. For example, the first electrode AE ​​may include a reflective electrode.

[0069] A hole control layer (HCL) can be disposed on the first electrode (AE). The hole control layer (HCL) may include a hole transport layer and further include a hole injection layer. An emitter layer (EML) can be disposed on the hole control layer (HCL). The emitter layer (EML) can be disposed in a region corresponding to the pixel aperture (PX-OP).

[0070] An electronic control layer (ECL) can be disposed on an emitter layer (EML). The ECL may include an electron transport layer and an electron injection layer. A second electrode (CE) can be disposed on the ECL. The second electrode (CE) may also be disposed on a pixel definition layer (PDL). The second electrode (CE) may include a transparent electrode.

[0071] A thin-film encapsulation layer (TFE) can be disposed on the second electrode (CE). The TFE can cover the display element layer (OL). The TFE can include, for example, sequentially stacked inorganic, organic, and inorganic layers. The inorganic layer can include inorganic materials and can protect the pixel from, for example, moisture and / or oxygen. The organic layer can include organic materials and can protect the pixel from foreign matter such as dust particles.

[0072] Figure 4 and Figure 5 The structure of the display panel DP shown is merely an example, and embodiments of the present invention are not limited thereto. For example, according to an embodiment, the display panel DP may include a glass encapsulation substrate instead of a thin-film encapsulation layer TFE, and may also include a sealing layer connecting the substrate SUB and the encapsulation substrate on the edge of the substrate SUB. The thin-film encapsulation layer TFE and the encapsulation substrate may each be defined as a cover layer covering the pixels.

[0073] The display module DM may further include a functional layer. For example, the display module DM may further include an impact-absorbing layer disposed between the window WIN and the anti-reflective layer RPL. The impact-absorbing layer can absorb external impacts applied to the display panel DP from outside the display device DD. Alternatively, the display module DM may further include a window protection layer disposed on the window WIN. The window protection layer may include, for example, a flexible plastic material.

[0074] According to embodiments of the present invention, the display module DM can be configured such that the layers other than the optical layer OPL can have a refractive index substantially the same as that of the window WIN. For example, when the window WIN comprises glass, the refractive index of the layers other than the optical layer OPL in the display module DM can have a value of about 1.5.

[0075] The display module DM may include multiple conductive patterns formed of metal, and may also include multiple dielectric layers comprising dielectric materials. The multiple conductive patterns and multiple dielectric layers may be arranged on the optical layer OPL. The dielectric layers may include organic dielectric layers and inorganic dielectric layers. The remaining layers of the display module DM may be defined as organic and inorganic dielectric layers (e.g., optically transparent layers) that allow light to pass through, and the organic and inorganic dielectric layers may have a refractive index of about 1.5. In an embodiment, the refractive index of the optically transparent organic dielectric layer and the optically transparent inorganic dielectric layer arranged on the optical layer OPL may be approximately the same as the refractive index of the window WIN.

[0076] Conductive patterns may include Figure 5 The light-emitting element OLED shown has electrodes AE and CE, and may also include... Figure 5 The diagram shows gates G1 and G2, sources S1 and S2, and drains D1 and D2. Organic and inorganic dielectric layers may include... Figure 5 The first dielectric layer 10 to the sixth dielectric layer 60 and the thin-film encapsulation layer TFE are shown. Organic and inorganic dielectric layers may include those that can be arranged on... Figure 3 The input sensing section ISP and the multiple dielectric layers in the anti-reflective layer RPL shown are illustrated.

[0077] Return to reference Figure 3 The protective layer PF can be placed below the display module DM and protect the display module DM. The protective layer PF may include a flexible material. The protective layer PF can be folded together with the display module DM.

[0078] According to embodiments of the present invention, the protective layer PF may include a material with a refractive index greater than that of the display module DM. For example, the protective layer PF may include a material with a refractive index greater than that of glass. For example, in an embodiment, the refractive index of the protective layer PF may be greater than that of the window WIN of the display module DM.

[0079] The protective layer PF can have a multi-layered structure. In an embodiment, such as... Figure 3 As shown, the protective layer PF may include a first protective layer PF1 and a second protective layer PF2. The second protective layer PF2 may be disposed below the first protective layer PF1.

[0080] The first protective layer PF1 may have a first refractive index. The first refractive index may be greater than the refractive index of the glass. For example, the first refractive index may be greater than about 1.5. The second protective layer PF2 may have a second refractive index. The second refractive index may be greater than the first refractive index.

[0081] However, there are no restrictions on the structure of the protective layer PF. For example, according to embodiments of the present invention, the protective layer PF can have a single-layer structure. For example, the protective layer PF can be formed by a single layer including one of the first protective layer PF1 and the second protective layer PF2, or the protective layer PF can be a multi-layer structure including the first protective layer PF1 and the second protective layer PF2.

[0082] According to an embodiment of the present invention, the support plate SP can be arranged below the protective layer PF. The support plate SP can be folded together with the display module DM and can increase the mechanical rigidity of the display device DD. The support plate SP can include, for example, stainless steel. However, there are no limitations on the material of the support plate SP.

[0083] The support plate SP may have an opening OP defined therein. The opening OP may overlap with the fingerprint detection area FDA. The opening OP may penetrate the support plate SP in the thickness direction (or third-party direction DR3). In this document, the third-party direction DR3 may also be referred to as the thickness direction of the display device DD.

[0084] The support plate SP may include a filler member RS ​​disposed in the opening OP. The filler member RS ​​may be optically transparent. For example, the filler member RS ​​may include a transparent polymer resin.

[0085] In an embodiment, the refractive index of the filler element RS can be approximately the same as the second refractive index of the second protective layer PF2. When the protective layer PF has a monolayer structure formed by one of the first protective layer PF1 and the second protective layer PF2, the refractive index of the filler element RS can be approximately the same as the refractive index of the monolayer protective layer PF.

[0086] However, embodiments of the present invention are not limited thereto. For example, according to an embodiment, the filling member RS ​​may comprise a material with a refractive index greater than or less than the second refractive index of the second protective layer PF2. Additionally, when the protective layer PF has a monolayer structure formed by one of the first protective layer PF1 and the second protective layer PF2, the refractive index of the filling member RS ​​may be greater than or less than the refractive index of the monolayer protective layer PF.

[0087] The filler element RS arranged in the opening OP can increase the mechanical stiffness of the support plate SP. The filler element RS can be optically transparent, and thus allow incident light to pass through.

[0088] According to an embodiment of the present invention, the sensor SS can be arranged below the filling member RS ​​of the support plate SP. The sensor SS can overlap with the fingerprint detection area FDA. The sensor SS can detect the user's fingerprint information, which can be used for authentication purposes. Such fingerprint information may also be referred to herein as fingerprint authentication information. When the user places his or her finger on or near the fingerprint detection area FDA, the fingerprint authentication information can be indicated by light received by the fingerprint detection area FDA.

[0089] The sensor SS can be, for example, an optical fingerprint sensor. The sensor SS can provide the user's fingerprint information via light incident on the fingerprint detection area FDA. The sensor SS may additionally include an optical system. For example, the sensor SS may include a collimator layer.

[0090] A sensor SS can block light of a specific wavelength. For example, a sensor SS may include an infrared cutoff filter. An infrared cutoff filter blocks infrared light emitted from external light. It also blocks infrared light propagating from outside the sensor SS toward the sensor SS. When the sensor SS is exposed to infrared light emitted from external light, fingerprint detection may fail. An infrared cutoff filter prevents the fingerprint sensor from receiving infrared light emitted from external light.

[0091] In this embodiment, the infrared cutoff filter is not disposed inside the sensor SS, but rather outside the sensor SS. In this case, the infrared cutoff filter can be placed between the sensor SS and the filling member RS.

[0092] In this embodiment, the sensor SS does not directly contact the filling member RS. For example, in this embodiment, an adhesive and a barrier layer may be further disposed between the sensor SS and the filling member RS. The adhesive may be disposed between the sensor SS and the filling member RS, and the sensor SS may be attached to the filling member RS ​​by the adhesive. The barrier layer may be disposed between the sensor SS and the filling member RS. The barrier layer may protect the sensor SS and may be implemented as a membrane attached to the sensor SS.

[0093] Various layers can be arranged between the protective layer PF and the support plate SP. For example, a cushion layer and a barrier layer can be arranged between the protective layer PF and the support plate SP.

[0094] A barrier layer can be disposed beneath the protective layer PF and can increase the resistance of the display module DM to compressive forces caused by external pressure. The barrier layer may comprise a flexible plastic material such as, for example, polyimide or polyethylene terephthalate.

[0095] A cushioning layer can be disposed below the barrier layer. The cushioning layer absorbs external impacts applied to the underside of the display module (DM), thereby protecting the display panel (DP). The cushioning layer may include an elastic foam sheet. The cushioning layer may include, for example, foam, sponge, polyurethane, or thermoplastic polyurethane.

[0096] Figure 6 The diagram shows the relationship between Figure 3 A perspective view of the overlapping window, optical layer, and sensor of the fingerprint detection area. For ease of description, Figure 6 The illustrations of layers other than the window WIN, the optical layer OPL of the display panel DP, and the sensor SS are omitted.

[0097] Reference Figure 6 At least one transmission aperture PH can be defined in the optical layer OPL between the window WIN and the sensor SS. For example, as Figure 6 As shown, the optical layer OPL can have multiple transmission holes PH. The transmission holes PH can be disposed in a first direction DR1 and a second direction DR2 and spaced apart from each other. The transmission holes PH can penetrate the optical layer OPL in its thickness direction (e.g., a third direction DR3). The transmission holes PH can define an optical system.

[0098] Figure 6 The example depicts nine transmissive apertures (PH) overlapping the fingerprint detection area (FDA). However, embodiments of the invention are not limited thereto. For example, according to embodiments of the invention, the number of transmissive apertures (PH) overlapping the fingerprint detection area (FDA) may be greater than nine or less than nine.

[0099] When viewed in a plan view, each of the transmission apertures PH can have a square shape. However, there is no limitation on the shape of the transmission apertures PH. For example, according to an embodiment, the transmission apertures PH can have a polygonal shape, a circular shape, or any other suitable shape.

[0100] According to an embodiment of the present invention, the fingerprint detection area FDA can be divided into a plurality of first areas A1 to A9. The first areas A1 to A9 can be positioned on a first direction DR1 and a second direction DR2. When viewed in a plan view, each of the first areas A1 to A9 can have a square shape.

[0101] The sum of the areas of the first regions A1 to A9 can be the same as the area of ​​the fingerprint detection region FDA. That is, the fingerprint detection region FDA can correspond to the first regions A1 to A9. In an embodiment, when viewed in a plan view, the first regions A1 to A9 can partially overlap each other. The first regions A1 to A9 can partially overlap each other in the first direction DR1 and the second direction DR2. The first regions A1 to A9 can overlap each other at portions adjacent to their edges.

[0102] According to an embodiment of the present invention, the sensor SS may have a light incident surface ISU divided into a plurality of second regions B1 to B9. The second regions B1 to B9 may be disposed in a first direction DR1 and a second direction DR2. When viewed in a plan view, each of the second regions B1 to B9 may have a square shape.

[0103] The sum of the areas of the second regions B1 to B9 can be approximately equal to the area of ​​the light-incident surface ISU of the sensor SS. That is, the light-incident surface ISU can correspond to the second regions B1 to B9. In an embodiment, when viewed in a planar view, the second regions B1 to B9 do not overlap with each other. The second regions B1 to B9 can be spaced apart from each other in the first direction DR1 and the second direction DR2. Each of the second regions B1 to B9 can include multiple sensor pixels.

[0104] According to embodiments of the present invention, the first regions A1 to A9 can correspond one-to-one with the transmission apertures PH of the optical layer OPL, and can also correspond one-to-one with the second regions B1 to B9. For example, in an embodiment, the corresponding first region A1, transmission aperture PH, and second region B1 can overlap each other, and this arrangement can be repeated among the corresponding first regions A2-A9, transmission apertures PH, and second regions B2-B9. According to embodiments of the present invention, the first regions A1 to A9, transmission aperture PH, and second regions B1 to B9 can correspond one-to-one with each other.

[0105] According to an embodiment of the present invention, the first light transmission path PEA1 can be defined between the corresponding first region A1 and the transmission aperture PH. The first light transmission path PEA1 can be defined above the transmission aperture PH.

[0106] When external light is incident on the first region A1, the external light can propagate along the first light transmission path PEA1, which serves as the path allowing the external light to reach the transmission aperture PH. The first light transmission path PEA1 can also be defined between each of the other first regions A2 to A9 and its corresponding transmission aperture PH. However, for ease of illustration, Figure 6 These additional first light transmission paths, PEA1, are omitted in the text.

[0107] According to an embodiment of the present invention, the second light transmission path PEA2 can be defined between the corresponding second region B1 and the transmission aperture PH. The second light transmission path PEA2 can be defined below the transmission aperture PH.

[0108] The second light transmission path PEA2 can be continuous with the first light transmission path PEA1. When light passes through the transmission aperture PH, it can propagate along the second light transmission path PEA2, which serves as the path allowing light to reach the second region B1 of the light incident surface ISU. The second light transmission path PEA2 can also be defined between each of the other second regions B2 to B9 and its corresponding transmission aperture PH. However, for ease of illustration, Figure 6 These additional second light transmission paths, PEA2, are omitted in the text.

[0109] According to an embodiment of the present invention, the first length L1 from the optical layer OPL to the window WIN can be less than the second length L2 from the optical layer OPL to the sensor SS. For example, when viewed on a third-direction DR3, the length from the transmission aperture PH to their corresponding first regions A1 to A9 can be less than the length from the transmission aperture PH to their corresponding second regions B1 to B9.

[0110] Figure 7 The diagram shows along Figure 6 The cross-sectional view taken from line II-II'. For ease of description, in Figure 7 In this structure, the upper UL layer can indicate the group comprising the pixel layer PXL, the thin-film encapsulation layer TFE, the input sensing portion ISP, the anti-reflective layer RPL, and the window WIN, all disposed on the optical layer OPL. The lower BL layer can indicate the group comprising the substrate SUB, the protective layer PF, and the filler RS ​​of the support plate SP, disposed between the optical layer OPL and the sensor SS. The refractive index of the lower BL layer can be greater than that of the upper UL layer. The refractive index of the lower BL layer can be greater than that of glass.

[0111] Figure 6 The first length L1 shown in the figure can roughly correspond to the thickness of the upper UL layer, and Figure 6 The second length L2 illustrated in the figure can substantially correspond to the thickness of the lower layer BL. Therefore, in the embodiment, the thickness of the lower layer BL can be greater than the thickness of the upper layer UL.

[0112] Reference Figure 6 and Figure 7 Regions A1, A2, and A3 can partially overlap each other. Regions A1, A2, and A3 can overlap each other at portions adjacent to their edges. For example, as... Figure 7 As shown, the portion of the first region A1 adjacent to the edge of the first region A1 can overlap with the portion of the first region A2 adjacent to the edge of the first region A2. Similarly, the portion of the first region A2 adjacent to another edge of the first region A2 can overlap with the portion of the first region A3 adjacent to the edge of the first region A3.

[0113] The first light transmission path PEA1 can be defined in the upper UL layer. The first light transmission path PEA1 can have a region that decreases in the downward direction. That is, the region of the first light transmission path PEA1 can decrease in the direction away from the window WIN and towards the optical layer OPL. For example, the region of the first light transmission path PEA1 can be the largest at the upper portion of the window WIN and the smallest at the lower portion of the circuit element layer CL.

[0114] In an embodiment, the first light transmission path PEA1 may be defined within the pixel definition layer PDL of the display element layer OL, and not within the light-emitting element OLED of the display element layer OL. For example, in an embodiment, as... Figure 7 As shown, the transmission aperture PH can overlap with the pixel-defining layer PDL, but does not overlap with the light-emitting element OLED.

[0115] According to an embodiment of the present invention, the upper UL may have optically transparent properties at a portion of the upper UL that defines the first light transmission path PEA1. Therefore, external light incident on the fingerprint detection area FDA can propagate through the first light transmission path PEA1 to reach the transmission aperture PH of the optical layer OPL.

[0116] The second light transmission path PEA2 can be defined in the lower layer BL. The second light transmission path PEA2 can have a region that increases in the downward direction. That is, the region of the second light transmission path PEA2 can increase in the direction away from the optical layer OPL and towards the sensor SS. For example, the region of the second light transmission path PEA2 can be the largest at the lower portion of the filling member RS ​​and the smallest at the upper portion of the substrate SUB.

[0117] According to an embodiment of the present invention, the lower layer BL may have optically transparent properties at a portion of the lower layer BL that defines the second light transmission path PEA2. Therefore, light passing through the transmission aperture PH can propagate through the second light transmission path PEA2 to reach the light incident surface ISU of the sensor SS.

[0118] According to an embodiment of the present invention, the second regions B1, B2, and B3 do not overlap with each other along the second light transmission path PEA2. When the second regions B1, B2, and B3 overlap, fingerprint detection may fail. For example, when the second regions B1, B2, and B3 overlap, the overlapping portion may redundantly contain fingerprints, and therefore, fingerprints may not be correctly identified. In this case, fingerprint authentication errors may occur. However, in the embodiment of the present invention, because the second regions B1, B2, and B3 do not overlap with each other along the second light transmission path PEA2, fingerprint detection can proceed normally.

[0119] Therefore, the sensor SS can detect the light incident on the fingerprint detection area FDA and can receive the user's fingerprint authentication information.

[0120] Figure 8 The diagram shows the incident light. Figure 6 A cross-sectional view of the path of light from the first zone to the second zone.

[0121] Reference Figure 8 Light LI can be incident on the first region A1 of the fingerprint detection area FDA of window WIN, and can reach the second region B1 of the light incident surface ISU of sensor SS. Light LI can be assumed to be incident on... Figure 6 The light on the outermost part of the first light transmission path PEA1 shown in the figure.

[0122] According to embodiments of the present invention, each layer of the display module DM (e.g., organic and inorganic layers) can have a refractive index substantially the same as that of glass. For example, each layer of the display module DM can have a refractive index of about 1.5. Therefore, light L1 can propagate substantially straight without refraction within the display module DM.

[0123] Light LI can be refracted at the first boundary surface BS1 between the substrate SUB and the first protective layer PF1. The first protective layer PF1 can have a first refractive index greater than that of glass (e.g., about 1.5). Therefore, at the first boundary surface BS1, the first angle θ1 (or incident angle) of light LI can be greater than the second angle θ2 (or refraction angle) of light LI.

[0124] Light LI can be refracted again at the second boundary surface BS2 between the first protective layer PF1 and the second protective layer PF2. The second protective layer PF2 can have a second refractive index greater than the first refractive index of the first protective layer PF1. Therefore, at the second boundary surface BS2, the second angle θ2 (or incident angle) of light LI can be greater than the third angle θ3 (or refraction angle) of light LI.

[0125] In this embodiment, the filling member RS ​​may have a refractive index substantially the same as the second refractive index of the second protective layer PF2. Therefore, light LI can propagate substantially straight without being refracted at the boundary between the second protective layer PF2 and the filling member RS. Light LI can pass through the filling member RS ​​to reach the second region B1.

[0126] When the refractive index of the protective layer PF beneath the display module DM is substantially equal to or less than the refractive index of the display module DM, the light LI incident on the first region A1 can reach the outside of the second region B1. In this case, the sensor SS may not detect the portion of the fingerprint information contained in the light LI, and therefore, a malfunction of the sensor SS may occur. The malfunction of the sensor SS may correspond to the aforementioned situation where the second regions B1, B2, and B3 overlap or partially overlap each other. Conversely, according to an embodiment of the present invention, the display device DD may include a protective layer PF disposed beneath the display module DM and having a refractive index greater than that of the display module DM. Therefore, according to an embodiment of the present invention, the light LI incident on the first region A1 can be controlled to have a stable path to the second region B1. Therefore, the reliability of the sensor SS can be increased. Normal operation of the sensor SS may correspond to the aforementioned situation where the second regions B1, B2, and B3 do not overlap each other.

[0127] Figure 9 and Figure 10 The figure shows a cross-sectional view of a display device according to an embodiment of the present invention.

[0128] Reference Figure 9 and Figure 10 For ease of explanation, further descriptions of the features and components described earlier can be omitted, and the main focus will be on their differences.

[0129] Reference Figure 9 The optical layer OPL-1 may further include a plurality of first lenses LE1. A single first lens LE1 may be arranged in each of the transmission apertures PH. A single first lens LE1 may include, for example, an upper lens LE1-U, a lower lens LE1-B, and an intermediate lens LE1-M.

[0130] The upper lens LE1-U can be disposed on the top surface of the optical layer OPL-1 adjacent to the transmission aperture PH. The upper lens LE1-U can have a convex shape on the third direction DR3.

[0131] The lower lens LE1-B can be positioned below the bottom surface of the optical layer OPL-1, adjacent to the transmission aperture PH. The lower lens LE1-B can have a convex shape on the third direction DR3.

[0132] The intermediate lens LE1-M can be positioned between the upper lens LE1-U and the lower lens LE1-B. The intermediate lens LE1-M can also be positioned within the transmission aperture PH.

[0133] The upper lens LE1-U, the lower lens LE1-B, and the middle lens LE1-M can be manufactured integrally or separately and then arranged.

[0134] However, the first lens LE1 is not limited to those described above. For example, in embodiments, one or both of the upper lens LE1-U, lower lens LE1-B, and intermediate lens LE1-M can be omitted from the first lens LE1. Additionally, the upper lens LE1-U and lower lens LE1-B can be concave lenses in the third direction DR3.

[0135] According to an embodiment of the present invention, as described above, the display device DD-1 may further include a first lens LE1 arranged in the transmission aperture PH, and thus the path of external light propagating toward the sensor SS can be effectively controlled.

[0136] The first lens LE1 can refract light toward the sensor SS. Because the first lens LE1 has a convex lens shape, light can be concentrated and provided to each of the second zones B1 to B9 without being widely dispersed.

[0137] Reference Figure 10 The protective layer PF-2 may include a plurality of second lenses LE2. Each of the plurality of second lenses LE2 may overlap with a corresponding transmission aperture PH. In an embodiment, the second lenses LE2 may be arranged on the first protective layer PF1-2.

[0138] The second lens LE2 may be defined by a recess RE formed on the first protective layer PF1-2. For example, the first protective layer PF1-2 may have a plurality of recesses RE on its bottom surface recessed in the third direction DR3. Each of the recesses RE may overlap with its corresponding transmission aperture PH. The first protective layer PF1-2 may have a concave shape in the third direction DR3 on its bottom surface where it overlaps with the recesses RE. Therefore, the first protective layer PF1-2 may function as a lens at the portion where it overlaps with the recesses RE (or the second lens LE2).

[0139] However, the second lens LE2 is not limited to those described above. For example, the second lens LE2 may be disposed on the top surface of the first protective layer PF1-2. Alternatively, the second lens LE2 may be disposed on the bottom or top surface of the second protective layer PF2.

[0140] According to an embodiment of the present invention, as described above, the display device DD-2 may further include a second lens LE2 disposed on the protective layer PF-2, and thus the path of external light propagating toward the sensor SS can be effectively controlled.

[0141] The second lens LE2 can refract light toward the sensor SS. Because the second lens LE2 has a convex lens shape, light can be concentrated and provided to each of the second zones B1 to B9 without being widely dispersed.

[0142] Figure 11 The figure shows a cross-sectional view of a display device according to an embodiment of the present invention.

[0143] Reference Figure 11 The support plate SP can have an opening OP that overlaps with the fingerprint detection area FDA. According to... Figure 11 In some embodiments, the display device DD-3 does not include the filling member RS. For example, in accordance with... Figure 11 In one embodiment, the opening OP does not include the filling member RS ​​disposed therein.

[0144] The sensor SS can be arranged in the opening OP. As described above, the first protective layer PF1 can have a first refractive index greater than that of glass (e.g., about 1.5), and the second protective layer PF2 can have a second refractive index greater than that of the first protective layer PF1. Therefore, as described above, the sensor SS can effectively receive light refracted at the first protective layer PF1 and the second protective layer PF2.

[0145] According to embodiments of the present invention, the display device may include a protective layer disposed below the display module and having a refractive index greater than that of the display module. Therefore, the path of light incident on the fingerprint detection area can be effectively controlled, thereby enabling the sensor to stably receive light. This increases the operational reliability of the sensor.

[0146] Although the invention has been specifically shown and described with reference to embodiments thereof, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A display device, comprising: A window, on which a fingerprint detection area is defined, and fingerprint information is detected in the fingerprint detection area; An optical layer is disposed below the window, and at least one transmission hole is defined in the optical layer that overlaps with the fingerprint detection area; A protective layer is disposed below the optical layer, wherein the refractive index of the protective layer is greater than the refractive index of the window; and The sensor is positioned beneath the protective layer and overlaps with the fingerprint detection area. Wherein, the distance from the optical layer to the window is less than the distance from the optical layer to the sensor, and The protective layer includes: A first protective layer having a first refractive index; and The second protective layer is disposed below the first protective layer and has a second refractive index greater than the first refractive index.

2. The display device according to claim 1, wherein, The at least one transmission hole is provided as a plurality of transmission holes, and When viewed in a plan view, the plurality of transmission holes are spaced apart from each other in a first direction or in a second direction intersecting the first direction.

3. The display device according to claim 2, wherein, When viewed in the plan view, the fingerprint detection area is divided into multiple first areas corresponding one-to-one with the plurality of transmission holes, and The multiple first regions partially overlap with each other.

4. The display device according to claim 2, wherein, The sensor includes a light incident surface that receives light incident from the fingerprint detection area. When viewed in the planar view, the light incident surface is divided into multiple regions corresponding to the plurality of transmission apertures. The multiple zones are spaced apart from each other.

5. The display device according to any one of claims 1 to 4, further comprising: The display module is located below the window. The display module includes: The optical layer; Multiple conductive patterns are arranged on the optical layer; and Organic and inorganic dielectric layers are disposed on the optical layer. The organic dielectric layer and the inorganic dielectric layer are optically transparent, and the refractive indices of the organic dielectric layer and the inorganic dielectric layer are the same as the refractive index of the window.

6. The display device according to claim 5, wherein, The display module further includes: A pixel layer is arranged below the window. The pixel layer includes a pixel defining layer and light-emitting elements disposed in pixel openings defined in the pixel defining layer. The transmission aperture overlaps with the pixel defining layer.

7. The display device according to claim 1, wherein, The optical layer includes: The first lens is arranged in the transmission aperture.

8. The display device according to claim 1, wherein, The protective layer includes: The lens overlaps with the transmission aperture.

9. The display device according to claim 1, wherein, The refractive index of the protective layer is greater than that of the glass.

10. The display device according to claim 1, wherein, The window includes glass.

11. The display device according to claim 5, wherein, The display module is foldable around a folding axis extending in one direction.

12. The display device according to claim 11, further comprising: A support plate is arranged between the protective layer and the sensor. The opening that overlaps with the sensor is defined within the support plate.

13. The display device according to claim 12, wherein, The support plate includes an optically transparent filling member disposed within the opening, and The sensor is positioned below the filling member.

14. The display device according to claim 12, wherein, The sensor is arranged in the opening.

15. A display device, comprising: The upper layer has a fingerprint detection area arranged on the top surface of the upper layer, wherein the fingerprint detection area receives light indicating fingerprint information; An optical layer is disposed below the upper layer and has multiple transmission holes, through which light penetrating the upper layer passes; A lower layer, disposed below the optical layer, wherein light passing through the plurality of transmission apertures is received on and passes through the lower layer, wherein the refractive index of the lower layer is greater than the refractive index of the upper layer; and The sensor is positioned below the lower layer and overlaps with the fingerprint detection area. The sensor receives the light that passes through the lower layer. Wherein, the thickness of the lower layer is greater than the thickness of the upper layer, and The lower layer includes a plurality of first lenses that overlap with the plurality of transmission holes.

16. The display device according to claim 15, wherein, The refractive index of the lower layer is greater than that of the glass.

17. The display device according to claim 15, wherein, The optical layer includes a plurality of second lenses arranged in the plurality of transmission apertures.

18. A display device, comprising: The display module includes a first non-foldable area, a second non-foldable area including a fingerprint detection area, and a foldable area arranged between the first non-foldable area and the second non-foldable area. Fingerprint information is detected in the fingerprint detection area, wherein the foldable area is foldable around a folding axis. A support plate is arranged below the display module, and an opening overlapping the fingerprint detection area is defined in the support plate; The sensor is arranged below the support plate and overlaps with the opening; and A protective layer is disposed between the display module and the support plate. The refractive index of the protective layer is greater than that of the display module, and The protective layer includes: A first protective layer having a first refractive index; and The second protective layer is disposed below the first protective layer and has a second refractive index greater than the first refractive index.

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