Display device

Abstract

This disclosure provides a display device, including a display panel, a light guide substrate, a light source, and an adhesive layer. The display panel includes a plurality of photosensitive elements. The light guide substrate is disposed on the display panel. The light source is disposed adjacent to the light guide substrate, and the plurality of photosensitive elements receive light emitted by the light source. The adhesive layer is disposed between the display panel and the light guide substrate, wherein the adhesive layer does not completely cover the display panel.

Description

Technical Field

[0001] This disclosure relates to a display device, and more particularly to a display device that can improve quality. Background Technology

[0002] Fingerprint recognition can be used for identity verification. Therefore, with the development of electronic device technology, the function of fingerprint recognition has been integrated into various electronic devices and is widely used. For example, in smartphones and other displays, users can manage electronic devices directly through fingerprint recognition without having to remember passwords. Furthermore, since the fingerprint recognition process is fast and difficult to forge, fingerprint recognition can provide good convenience or security.

[0003] Generally, electronic devices use optically clear adhesive (OCA) to bond the cover glass and display panel. However, if the cover glass and display panel are not bonded properly, the optical adhesive may reduce the performance of fingerprint sensing or recognition. Summary of the Invention

[0004] This disclosure provides a display device, the display device including a display panel including a plurality of light sensing elements; a light guide substrate disposed on the display panel; a light source disposed adjacent to the light guide substrate, and the plurality of light sensing elements receiving light emitted by the light source; and an adhesive layer disposed between the display panel and the light guide substrate, wherein the adhesive layer does not completely cover the display panel. Attached Figure Description

[0005] Figure 1 This is a top view schematic diagram of a display device in one embodiment of the present disclosure.

[0006] Figures 2 to 6 For along Figure 1 A schematic diagram of the cross section drawn along section line A-A'.

[0007] Explanation of reference numerals in the attached figures: 120 - Light source; 120-1, 160-1, 184-1, 360-1, 484-1, 560-1; 590-1, 690-1, PRR-1, R0-1, R1-1, SR-1 - Boundary; 140 - Light guide substrate; 186, 186-1 - Photosensitive element; 10, 30, 40, 50, 60 - Display device; 140S1, 140S2, 140S3 - Surface; 160, 360, 560 - Adhesive layer; 180, 480 - Display panel; 182a, 1 82b, 482a, 482b - Polarizing layer; 184, 188, 484, 488 - Substrate; 187, 487 - Masking layer; 590, 690 - Optical film; AA - Display area; B1, B2 - Invalid area; BJ - Object; D - Distance; DN - Normal direction; LL - Light; n0, n1, n4, n5 - Refractive index; PP - Peripheral area; PRR - Optical identification area; R0, R1, R2, R3 - Restriction area; SPT - Dirt; SR - Sensing element area; W0, W1, W2, W3 - Width; θc - Critical angle. Detailed Implementation

[0008] This disclosure has been specifically shown and described with reference to embodiments and their specific features. The embodiments set forth below should be considered illustrative rather than restrictive. It will be apparent to those skilled in the art that various changes and modifications in form and detail can be made without departing from the spirit and scope of this disclosure.

[0009] Before further describing the various embodiments, the following will explain the specific terms used throughout the text.

[0010] The meanings of the terms “on,” “above,” and “on top of” should be interpreted in the broadest sense, such that “on,” “above,” and “on top of” not only mean “directly on” something but also include the meaning of being on something with other intervening features or layers in between, and that “directly on,” “directly above,” and “directly on top of” not only mean “above” something but can also include the meaning of being “above” something without other intervening features or layers in between.

[0011] In addition, terms such as "bottom," "below," "above," and "top" are used to describe the relative positions of different components in the diagram. However, when the diagram is flipped upside down, the aforementioned "above" becomes "below." It should be understood that, in addition to the directions shown in the diagram, spatial relative terms are intended to cover different orientations of the equipment in use or operation.

[0012] The terms “forming” or “setting” are used below to describe the act of applying a material layer to a substrate. These terms are intended to describe any feasible layer forming techniques, including but not limited to thermal growth, sputtering, evaporation, chemical vapor deposition, epitaxial growth, electroplating, etc.

[0013] The use of ordinal numbers such as "first," "second," etc., in the specification and claims to modify elements of the claims does not in itself imply or represent any prior ordinal number of the claimed element, nor does it represent the order of one claimed element with another claimed element, or the order of manufacturing process. The use of these ordinal numbers is only to enable a claim element with a certain name to be clearly distinguished from another claim element with the same name.

[0014] It should be understood that although the terms first, second, etc., may be used herein to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms are used only to distinguish one element, component, region, layer, and / or part from another element, component, region, layer, and / or part. Therefore, without departing from the teachings of this disclosure, the first element, first component, first region, first layer, or first part discussed below may also be referred to as a second element, second component, second region, second layer, or second part.

[0015] In addition, phrases such as "within the range of the first value and the second value" or "within the range of the first value and the second value" indicate that the range includes the first value, the second value, and other values ​​in between.

[0016] It should be understood that the following examples illustrate different technical features, but these technical features may be used in combination or mixed in different ways without conflicting with each other.

[0017] Certain terms are used in the specification and claims to refer to specific elements. However, it should be understood by those skilled in the art that this disclosure pertains to that of the manufacturer that may use different terms to refer to the same element. Moreover, this specification and claims do not distinguish elements by differences in name, but by differences in the overall technology of the elements.

[0018] The term "comprising" as used throughout this specification and claims is an open-ended term and should be interpreted as "including but not limited to". When the terms "comprising" and / or "having" are used in this specification, they specify the presence of the stated features, areas, steps, operations and / or elements, but do not exclude the presence or addition of one or more other features, areas, steps, operations, elements and / or combinations thereof.

[0019] Furthermore, the term "coupled" here includes any direct and indirect means of connection. Therefore, if the text describes a first device coupled to a second device, it means that the first device can be directly connected to the second device, or can be indirectly connected to the second device through other devices or other means of connection.

[0020] To enable those skilled in the art to further understand this disclosure, embodiments of the disclosure are provided below, along with detailed descriptions of the disclosure's structure and intended effects in conjunction with the accompanying drawings. It should be noted that the drawings are simplified schematic diagrams; therefore, only elements and their combinations relevant to the disclosure are shown, with some elements omitted to provide a clearer description of the basic architecture or implementation method of the disclosure. The actual elements and layout may be more complex.

[0021] In addition, for ease of explanation, the components shown in the accompanying drawings are not drawn to scale according to the actual number, shape, and size of the components. The detailed scale can be adjusted according to the design requirements.

[0022] The electronic devices disclosed herein may include, for example, display devices, antenna devices, sensing devices, touch displays, curved displays, or free-shape displays, and may also be bendable or flexible splicing electronic devices, but are not limited thereto. Electronic devices may include, for example, light-emitting diodes (LEDs), liquid crystals, fluorescent, phosphorescent, quantum dot (QD) displays, other suitable display media, or combinations thereof, but are not limited thereto. Light-emitting diodes (LEDs) may include, for example, organic light-emitting diodes (OLEDs), inorganic light-emitting diodes, mini LEDs, micro LEDs, or quantum dot (QD) displays (e.g., QLEDs, QDLEDs), or other suitable materials or any arrangement and combination thereof, but are not limited thereto. Electronic devices may be, for example, liquid crystal antennas, but are not limited thereto. The electronic devices disclosed herein may be any arrangement and combination of the foregoing, but are not limited thereto. The electronic device can be rectangular, circular, polygonal, have curved edges, or other suitable shapes. It may include peripheral systems such as drive systems, control systems, light source systems, and shelving systems to support display devices or antenna devices. The electronic device disclosed herein can be used in electronic products capable of displaying images, such as laptops and smartphones, but is not limited thereto. The following will use a display device as an example.

[0023] Please refer to Figure 1 and Figure 2 , Figure 1 This is a top view schematic diagram of a display device 10 according to one embodiment of the present disclosure. Figure 2 For along Figure 1The diagram shows a cross-sectional view along line A-A'. The display device 10 has a display area AA, a peripheral area PP, and a sensing element area SR. The display device 10 includes a plurality of light sources 120, a light guide substrate 140, an adhesive layer 160, and a display panel 180. The light sources 120 are disposed adjacent to the light guide substrate 140, and the adhesive layer 160 is disposed between the light guide substrate 140 and the display panel 180. According to some embodiments, the light guide substrate 140 may be disposed on the display panel 180. The display panel 180 includes a polarizing layer 182a, a polarizing layer 182b, a substrate 184, a substrate 188, a plurality of photosensitive elements 186, and a shielding layer 187. The photosensitive elements 186 are used to receive light LL emitted by the light sources 120. In some embodiments, the substrate 188 may include a driving circuit, a display unit, a sensing circuit, or a sensing unit, which may be disposed in the display area AA. In some embodiments, the peripheral circuitry of the substrate 188 may be disposed in the peripheral area PP. The peripheral circuitry may include, for example, gate drive circuitry, data line drive circuitry, a demultiplexer (DeMux), or / and other functional circuitry. The display area AA may be considered an active area. The peripheral area PP may be considered a non-active area.

[0024] The substrate 188 can be a rigid substrate or a flexible substrate. Materials for the substrate 188 include, for example, glass, quartz, ceramic, sapphire, or plastic, but this disclosure is not limited thereto. In some embodiments, when the substrate 188 is a flexible substrate, it may include suitable flexible materials such as polycarbonate, polyimide, polypropylene, or polyethylene terephthalate, other suitable materials, or combinations thereof, but is not limited thereto. Furthermore, the light transmittance of the substrate 188 is not limited; that is, the substrate 188 can be a transparent substrate, a semi-transparent substrate, or an opaque substrate. The substrate 188 may include an active element layer, a passive element layer, other suitable film layers, or combinations thereof. The substrate 188 may, for example, include a thin film transistor (TFT) having a semiconductor material, such as amorphous silicon, low-temperature polycrystalline silicon (LTPS), or metal oxide. Thin-film transistors can be top-gate thin-film transistors, bottom-gate thin-film transistors, double-gate or dual-gate thin-film transistors, or combinations of the above materials, but are not limited thereto. In some embodiments, different thin-film transistors may have the different semiconductor materials described above.

[0025] In short, the adhesive layer 160 disposed between the light guide substrate 140 and the display panel 180 does not completely cover the display panel 180. As a result, when the light source 120 emits light LL to the light guide substrate 140, the light LL is transmitted within the light guide substrate 140 via total internal reflection, thereby reducing transmission loss or ensuring imaging contrast. The term "coverage" in this disclosure refers to the presence or absence of other layers between the light guide substrate 140 and the display panel 180.

[0026] The light guide substrate 140 may have a surface 140S1 (also referred to as a first surface), a surface 140S2 (also referred to as a second surface) disposed opposite to the surface 140S1, and a surface 140S3 adjacent to the surface 140S2 as an interface. In some embodiments, the light source 120 and a plurality of photosensitive elements 186 may be disposed adjacent to the surface 140S1 of the light guide substrate 140 to image an object BJ placed on the surface 140S2. Specifically, the light source 120 and the plurality of photosensitive elements 186 may face the surface 140S1 of the light guide substrate 140 to emit light LL to the light guide substrate 140. When the light LL is transmitted to the location of the object BJ (e.g., a human finger), the light LL may be reflected by the object BJ and received by the photosensitive elements 186, thereby detecting the object BJ or further performing fingerprint identification. In some embodiments, light LL can be incident on light guide substrate 140 along a normal direction DN, or light LL can be incident on light guide substrate 140 at an angle relative to the normal direction DN. In some embodiments, light source 120 can be used to provide a collimated beam or multiple collimated beams, such that light LL hardly diverges with distance. In some embodiments, the light LL provided by light source 120 is mainly distributed within a solid angle, making light source 120 a concentrated light source. In some embodiments, light source 120 may include a light-emitting diode or a laser (Light Amplification by Stimulated Emission of Radiation) light source. The wavelength of light LL emitted by light source 120 can be adjusted according to different design considerations; for example, light LL may be visible light, or light LL may be infrared light that is not perceptible to the human eye.

[0027] When light LL is incident on the light guide substrate 140, it can be reflected at the interface between the light guide substrate 140 and other media. Surface 140S3 is located at one edge of the light guide substrate 140. Surface 140S3 can be curved or inclined, thus forming an arc or bevel of the light guide substrate 140. The position of the light source 120 can correspond to the position of surface 140S3; for example, the light source 120 can partially overlap with surface 140S3. In this way, light LL can be incident on surface 140S3 and reflected, so that light LL can be tilted at an angle θ relative to the normal of surface 140S1 or surface 140S2, where the angle θ can be greater than zero.

[0028] The light guide substrate 140 can serve as a light guide element, for example, to allow light LL to be transmitted within the display device 10. When light LL is incident from the light guide substrate 140 onto a medium with a lower refractive index, and the incident angle θ (i.e., the angle between the light LL and the normal to surface 140S1 or surface 140S2) is greater than or equal to the critical angle θc, the light LL can undergo total internal reflection at the interface between the light guide substrate 140 and the medium with a lower refractive index. This allows most of the light LL to be reflected at the interface, and then reflected again at the opposite interface. Thus, most of the light LL can be confined within the light guide substrate 140 and transmitted within it, reducing transmission loss. In some embodiments, the refractive index (n1) of the light guide substrate 140 is greater than the refractive index (n0) of air; therefore, air can be used as a medium with a lower refractive index. In some embodiments, the refractive index of the light guide substrate 140 may be different from that of human skin (e.g., 1.39). For example, the refractive index of the light guide substrate 140 may be greater than that of human skin.

[0029] The light guide substrate 140 can be a rigid substrate or a flexible substrate. The material of the light guide substrate 140 includes, for example, glass, quartz, ceramic, sapphire, or plastic. For instance, the light guide substrate 140 can be formed from transparent tempered glass, allowing it to function as a cover glass, but this disclosure is not limited thereto. In some embodiments, when the light guide substrate 140 is a flexible substrate, it may include suitable flexible materials such as polycarbonate (PC), polyimide (PI), polypropylene (PP), or polyethylene terephthalate (PET), other suitable materials, or combinations thereof, but is not limited thereto. The light transmittance of the light guide substrate 140 is not limited; that is, the light guide substrate 140 can be a transparent substrate or a semi-transparent substrate.

[0030] After multiple reflections within the light guide substrate 140, light LL may be incident from the light guide substrate 140 onto the adhesive layer 160. In some embodiments, the refractive index of the adhesive layer 160 may be substantially equal to the refractive index of the light guide substrate 140, or the refractive index of the adhesive layer 160 may be close to the refractive index of the light guide substrate 140. In this way, light LL will not undergo total internal reflection at the interface between the light guide substrate 140 and the adhesive layer 160, allowing light LL to be incident from the light guide substrate 140 onto the adhesive layer 160. The adhesive layer 160 used to bond the light guide substrate 140 and the display panel 180 may include, but is not limited to, optically clear adhesive (OCA) or pressure-sensitive adhesive (PSA). The adhesive layer 160 may include photocurable adhesive or heat-curable adhesive, but is not limited to these.

[0031] Light LL may be incident from the adhesive layer 160 onto the polarizing layer 182a. In some embodiments, the refractive index of the polarizing layer 182a may be substantially equal to the refractive index of the adhesive layer 160, or the refractive index of the polarizing layer 182a may be close to the refractive index of the adhesive layer 160. In this way, the light LL will not undergo total internal reflection at the interface between the adhesive layer 160 and the polarizing layer 182a, and the light LL can be further transmitted from the adhesive layer 160 to the polarizing layer 182a of the display panel 180. The polarizing layer 182a may be disposed opposite to the polarizing layer 182b. The polarizing layer 182a or polarizing layer 182b can filter out light with a specific polarization direction from the light LL and block light with other polarization directions, thereby serving as an optical filter. The polarization direction of polarizing layer 182a may be the same as or different from the polarization direction of polarizing layer 182b. For example, the polarization direction of polarizing layer 182a may be parallel to or perpendicular to the polarization direction of polarizing layer 182b. Polarizing layer 182a or polarizing layer 182b may be glossy or matte. In some embodiments, display panel 180 may selectively remove polarizing layer 182a or polarizing layer 182b.

[0032] Light LL may be incident from polarizing layer 182a onto substrate 184. In some embodiments, the refractive index of substrate 184 may be substantially equal to the refractive index of polarizing layer 182a, or the refractive index of substrate 184 may be close to the refractive index of polarizing layer 182a. In this way, light LL will not undergo total internal reflection at the interface between polarizing layer 182a and substrate 184, and light LL can be further transmitted from polarizing layer 182a to substrate 184 of display panel 180. In some embodiments, substrate 184 may include a filter layer or other suitable film layer. In some embodiments, substrate 184 may serve as a color filter, and through the color resist of substrate 184, substrate 184 can be used to convert grayscale input into color output. Substrate 184 may be a rigid substrate or a flexible substrate. The material of substrate 184 includes, for example, glass, quartz, ceramic, sapphire, or plastic, but this disclosure is not limited thereto. In some embodiments, when the substrate 184 is a flexible substrate, it may include a suitable flexible material, such as polycarbonate, polyimide, polypropylene or polyethylene terephthalate, other suitable materials or combinations thereof, but is not limited thereto. Furthermore, the light transmittance of the substrate 184 is not limited; that is, the substrate 184 may be a light-transmitting substrate or a semi-light-transmitting substrate.

[0033] Light LL may be incident from substrate 184 onto photosensitive element 186, which receives the light LL emitted by light source 120 and can analyze the light LL. For example... Figure 2 As shown, the light source 120 and the photosensitive element 186 are disposed adjacently on surface 140S1 of the light guide substrate 140 for imaging a surface 140S2 disposed opposite to surface 140S1. In some embodiments, the photosensitive element 186 may include an optical sensor or other suitable type of sensor. In some embodiments, the photosensitive element 186 may include a photodiode or a PIN diode having an undoped intrinsic semiconductor region between p-type and n-type semiconductors. The photosensitive element 186 may be a transducer for photoelectric conversion. The photosensitive element 186 can be used for fingerprint recognition. The photosensitive elements 186 are distributed in the sensing element region SR. The photosensitive elements 186 may be arranged in an array in the sensing element region SR. In some embodiments, the sensing element region SR is located in the display area AA.

[0034] In some embodiments, an optical identification region (PRR) can be defined to ensure imaging contrast. That is, since light LL may not undergo total internal reflection at the interface between the light guide substrate 140 and the object BJ, the light LL incident from the light guide substrate 140 to the object BJ and then reflected or scattered back to the light guide substrate 140 may experience transmission loss or optical path offset. In this case, there may be a positional correlation between the optical identification region (PRR) touched by the object BJ and the sensing element region (SR) distributed by the photosensing element 186 to ensure image quality. For example, such as... Figure 2 As shown, the boundary PRR-1 of the optical identification region PRR furthest from the display area AA is located within a specific range, which ensures image quality. More specifically, the boundary SR-1 of the sensing element area SR closest to the light source 120 extends a distance D along a direction perpendicular to the normal of the display panel 180 (e.g., the negative Y direction). The area within this distance D is defined as the optical identification region PRR. That is, the boundary PRR-1 of the optical identification region PRR is located within the aforementioned distance D, which ensures image quality. The boundary SR-1 of the sensing element area SR can be defined as the edge of the plurality of photosensitive elements 186 in the sensing element area SR that is closest to the shielding layer 187, for example... Figure 2 The edge of the light sensing element 186-1 can be defined as boundary SR-1, and D = (H1 + H2 + H3) × tanθc, where θc is the critical angle corresponding to the interface between the light guide substrate 140 and air. The critical angle θc can be obtained by Snell's Law. H1 is the thickness of substrate 184. The total thickness H2 of adhesive layer 160 and polarizing layer 182a can be defined as the distance between the top surface of substrate 184 closest to polarizing layer 182a and the bottom surface of light guide substrate 140 closest to adhesive layer 160. That is, H2 is the sum of the thickness of adhesive layer 160 and the thickness of polarizing layer 182a of display panel 180. The thickness H3 of light guide substrate 140 can be defined as the distance between surface 140S1 and surface 140S2 of light guide substrate 140, and the thicknesses H1, H2, and H3 are all greater than zero. In some embodiments, the term "thickness" as used in this disclosure may refer to the maximum thickness in the z-direction, and the term "distance" as used in this disclosure may refer to the maximum distance in the y-direction, but are not limited thereto.

[0035] To ensure image contrast, such as Figure 2As shown, the edge 160-1 of the adhesive layer 160 closest to the light source 120 is located within the optical recognition region PRR. That is, the adhesive layer 160 disposed between the light guide substrate 140 and the display panel 180 does not completely cover the display panel 180, allowing the light guide substrate 140 to be surrounded or enclosed by a medium with a low refractive index. Even if the light LL may have been reflected multiple times on the light guide substrate 140 before passing through the object BJ, as long as the angle θ of the light LL reflection (i.e., the angle between the light LL and the normal to surface 140S1 or surface 140S2) is greater than or equal to the critical angle θc corresponding to the interface between the light guide substrate 140 and air, the light LL can undergo total internal reflection at the interface between the light guide substrate 140 and air, thereby confining the light LL to the light guide substrate 140. Since the light LL is transmitted within the light guide substrate 140 by total internal reflection before passing through the object BJ, it is beneficial to improve the imaging contrast of the light LL at the sensing element region SR, such as fingerprint imaging contrast, thereby ensuring imaging quality.

[0036] like Figure 2 As shown, in the embodiments disclosed herein, the sensing element region SR has a boundary SR-1, which can be the edge of the photosensitive element 186 in the sensing element region SR that is closest to the shielding layer 187. The light source 120 can have a boundary 120-1, which can be the edge of the light source 120 in the y-direction that is closest to the display panel 180. In some embodiments, the range from boundary SR-1 to boundary 120-1 can be divided into, for example, four restricted areas, such as... Figure 2The diagram shows a restricted area R0, a first restricted area R1, a second restricted area R2, and a third restricted area R3. Restricted area R0, the first restricted area R1, and the second restricted area R2 can be defined as an invalid area B1. In the disclosed embodiments, restricted area R0 may have a width W0, the first restricted area R1 may have a width W1, the second restricted area R2 may have a width W2, and the third restricted area R3 may have a width W3. Specifically, the width W0 of restricted area R0 can be defined by the thickness H1 of substrate 184 and the critical angle θc, i.e., W0 = H1 × tanθc, but is not limited thereto. Similarly, the width W1 of the first restricted area R1 can be defined by the total thickness H2 of the adhesive layer 160 and the polarizing layer 182a, the thickness H3 of the light guide substrate 140, and the critical angle θc, i.e., W1 = (H2 + 2 × H3) × tanθc, but is not limited thereto. The width W2 of the second restriction zone R2 can be defined as the maximum distance in the y-direction between the boundary R1-1 of the first restriction zone R1 furthest from the restriction zone R0 and the boundary 184-1 of the substrate 184. The width W3 of the third restriction zone R3 can be defined as the maximum distance in the y-direction between the boundary 184-1 of the substrate 184 and the boundary 120-1 of the light source 120. In some embodiments, the widths W0 and W1 are both greater than zero. In other embodiments, the ratio of width W1 to width W0 can be greater than or equal to 1 and less than or equal to 20. In some embodiments, the ratio of width W2 to width W1 can be greater than or equal to 0 and less than or equal to 60. The ratio of width W3 to width W1 can be greater than or equal to 0 and less than or equal to 10. According to some embodiments, the units of widths W0, W1, W2, and W3 can be millimeters (mm) or centimeters (cm), and the units of the critical angle θc can be angles or radians; this disclosure is not limited thereto.

[0037] In some embodiments, the distance between an edge of a substrate of the display panel 180 and a plurality of photosensitive elements 186 may be greater than or equal to W0+W1. For example, the distance between the edge 184-1 of the substrate 184 of the display panel 180 and the boundary SR-1 of the sensing element region SR may be greater than or equal to W0+W1.

[0038] In some embodiments disclosed herein, a boundary 160-1 of the adhesive layer 160 may be located within the confinement region R0. That is, the maximum distance in the y-direction from the boundary SR-1 to the boundary 160-1 of the adhesive layer 160 may be less than or equal to the width W0 of the confinement region R0. This is to ensure imaging contrast or to ensure that most of the light LL can be transmitted through the light guide substrate 140 to the sensing element region SR, allowing multiple photosensitive elements 186 to receive it. In other words, when the boundary 160-1 of the adhesive layer 160 is located within the confinement region R0, the first confinement region R1 may not have an interface between the adhesive layer 160 and the light guide substrate 140, allowing the light LL to undergo total internal reflection at the interface between the light guide substrate 140 and air. For example, in the first restricted region R1, the surface 140S1 of the light guide substrate 140 is the interface between air (refractive index n0) and the light guide substrate 140 (refractive index n1), where n1 is greater than n0. When the incident angle of light LL onto surface 140S1 is greater than the critical angle θc, light LL will undergo total internal reflection at this interface. Similarly, when light LL is incident onto surface 140S2 of the light guide substrate 140, total internal reflection will also occur at surface 140S2. After light LL is transmitted to the restricted region R0 through multiple total internal reflections, the surface 140S1 located in the restricted region R0 becomes the interface between the adhesive layer 160 and the light guide substrate 140. The refractive index of the adhesive layer 160 can be approximately the same as or not significantly different from the refractive index of the light guide substrate 140. When light LL is incident onto surface 140S1 located in the restricted region R0, total internal reflection is disrupted, allowing light LL to be incident into the restricted region R0 and the sensing element region SR, where multiple photosensitive elements 186 can receive it. By designing the boundary 160-1 of the adhesive layer 160 in the confinement area R0, the loss of light LL emitted by the light source 120 in the light guide substrate 140 can be reduced, and most of the light LL emitted by the light source 120 can be transmitted to the sensing element area SR, ensuring imaging contrast.

[0039] The above are merely embodiments of this disclosure, and those skilled in the art can make different changes and modifications accordingly. The following will describe different embodiments of this disclosure, and for the sake of simplicity, identical parts will not be repeated. Furthermore, identical elements in the various embodiments of this disclosure are labeled with the same reference numerals to facilitate comparison between the embodiments.

[0040] Figure 3 In another embodiment of this disclosure, along Figure 1 The cross-sectional view of a display device 30 drawn along line A-A' shows an architecture similar to... Figure 1 The architecture of the display device 10 shown is such that the same components are represented by the same symbols. For example... Figure 3As shown, an edge 360-1 of the adhesive layer 360 of the display device 30 is located in the first restricted area R1. That is, the distance between the edge 360-1 of the adhesive layer 360 and the boundary SR-1 of the sensing element area SR is greater than or equal to W0. The distance between the edge 360-1 of the adhesive layer 360 and the photosensitive element 186 is greater than or equal to W0. More specifically, a portion of the surface 140S1 of the light guide substrate 140 located in the first restricted area R1 is the interface between the light guide substrate 140 (refractive index n1) and air (refractive index n0), and another portion is the interface between the light guide substrate 140 and the adhesive layer 360. Therefore, a portion of the light LL can undergo total internal reflection at the interface between the light guide substrate 140 and air. By placing the edge 360-1 of the adhesive layer 360 within the first restricted area R1, a portion of the interface between the light guide substrate 140 and the air, and a portion of the interface between the light guide substrate 140 and the adhesive layer 360, can be present within the first restricted area R1. This can enhance the bonding between the light guide substrate 140 and the display panel 180, or improve reliability. In some embodiments, the distance between the edge 360-1 of the adhesive layer 360 and the boundary SR-1 of the sensing element area SR can be greater than or equal to (W0+H1+H2)×tanθc, but is not limited thereto. The boundary SR-1 of the sensing element area SR can be defined as the edge of the plurality of photosensitive elements 186 in the sensing element area SR that is closest to the shielding layer 187, for example... Figure 3 The edge of the marked photosensitive element 186-1 can be defined as boundary SR-1.

[0041] In some embodiments, the distance between the edge 360-1 of the adhesive layer 360 and the boundary SR-1 of the sensing element region SR may be greater than or equal to (W0+H1+H2)×tanθc, but is not limited thereto. In some embodiments, the location of the edge 360-1 of the adhesive layer 360 may be less than or equal to one-third of the first restriction region R1, that is, the distance between the edge 360-1 of the adhesive layer 360 and the boundary SR-1 of the sensing element region SR may be substantially equal to (W0+W1 / 3), but is not limited thereto.

[0042] Figure 4 In another embodiment of this disclosure, along Figure 1 The diagram shows a cross-sectional view of a display device 40 drawn along section line A-A'. Please refer to... Figure 4 The display device 40 may not have a restricted area W2; for example, the display device 40 may have a narrower peripheral area. Specifically, the area from boundary SR-1 to boundary 120-1 can be divided into, for example, three restricted areas. Figure 4The diagram shows a restricted area R0, a first restricted area R1, and a third restricted area R3. Restricted areas R0 and R1 can be defined as an invalid area B1. In the disclosed embodiments, restricted area R0 can have a width W0, first restricted area R1 can have a width W1, and third restricted area R3 can have a width W3. The width W0 of restricted area R0 can be defined by the thickness H1 of substrate 484 and the critical angle θc, i.e., W0 = H1 × tanθc, but is not limited thereto. Similarly, the width W1 of the first restricted area R1 can be defined as the maximum distance in the y-direction between the boundary R0-1 furthest from boundary SR-1 of restricted area R0 and the boundary 484-1 of substrate 484. The width W3 of the third restricted area R3 can be defined as the maximum distance in the y-direction between the boundary 484-1 of substrate 484 and the boundary 120-1 of light source 120, but is not limited thereto; the size of restricted area W3 can also be adjusted according to different requirements.

[0043] The position of the boundary 160-1 of the adhesive layer 160 of the display device 40 can also be adjusted according to the position of the boundary 360-1 of the adhesive layer 360 of the display device 30. That is, the boundary 160-1 of the adhesive layer 160 of the display device 40 can be set within the restricted area R0 or the sensing element area SR, so that the surface 140S1 located in the first restricted area R1 is the interface between the light guide substrate 140 and the air. This facilitates the transmission of light LL within the light guide substrate 140 by total internal reflection before passing through the object BJ, and improves the imaging contrast of light LL at the sensing element area SR, thereby ensuring imaging quality. Similarly, the boundary 160-1 of the adhesive layer 160 of the display device 40 can be set in the first restricted area R1, so that a part of the surface 140S1 located in the first restricted area R1 is the interface between the light guide substrate 140 and the air, and another part is the interface between the light guide substrate 140 and the adhesive layer 360, thereby enhancing the bonding between the light guide substrate 140 and the display panel 180 and improving reliability.

[0044] In some embodiments, the photosensing element 186 may be stacked on the substrate 488. The material of the substrate 488 and the components it contains are similar to those of the substrate 188, and can be referred to the foregoing description, so they will not be repeated here.

[0045] A shielding layer 487 is located between substrates 484 and 488, and is disposed adjacent to the photosensitive element 186. The shielding layer 487 may contain a black matrix or a black color resist, but is not limited thereto. The shielding layer 487 may be made of a material that is opaque or has a light transmittance of less than or equal to 5% to provide a shielding effect, such as shielding the peripheral circuitry of substrate 488.

[0046] The display device 40 may include a driving circuit, a display unit, a sensing circuit, or a sensing unit, which may be disposed in the display area AA. The optical identification area PRR may be adjacent to one edge of the display area AA. In some embodiments, one edge of the display area AA may overlap with the boundary SR-1 of the sensing element area SR. In other words, the distance between one edge of the display area AA and the boundary SR-1 of the sensing element area SR may be less than or equal to 0.5 cm. Please refer to... Figure 1 and Figure 4 The peripheral circuitry of the display device 40 may be disposed in the peripheral area PP, and at least part of the shielding layer 487 may be located in the peripheral area PP. The peripheral circuitry may include, for example, gate drive circuitry, data line drive circuitry, demultiplexer (DeMux) and / or other functional circuitry. The display area AA may be considered an active area, and the peripheral area PP may be considered a non-active area.

[0047] Please refer to Figure 5 , Figure 5 In another embodiment of this disclosure, along Figure 1 A cross-sectional schematic diagram of a display device 50 drawn along section line A-A'. Figure 5 The architecture of the display device 50 shown is similar to Figure 2 The display device 10 shown uses the same symbols for the same components. The display device 50 also includes a first optical film 590 disposed between the light guide substrate 140 and an adhesive layer 560 of the display device 50. In some embodiments, the first optical film 590 is disposed on the surface 140S1 of the light guide substrate 140. In some embodiments, the first optical film 590 can adjust the position of the optical recognition area PRR, so that fingerprint recognition can be performed at various locations in the display area AA, not limited to a specific location of the display device 50. For example, the center of the optical recognition area PRR can be approximately aligned with the center of the display area AA, or the optical recognition area PRR can be located between the center of the display area AA and the edge of the display area AA. For example, there can be a region NR between the optical recognition area PRR and the light source 120, this region NR being the display area and may not contain multiple photosensitive elements 186. In some embodiments, the optical recognition area PRR can at least partially overlap with the display area AA.

[0048] In some embodiments, the first optical film 590 may not overlap with the photosensing element 186. The distance between an edge 590-1 of the first optical film 590 away from the light source 120 and the boundary PRR-1 of the optical identification region PRR closest to the light source 120 may be less than or equal to 0.5 cm. Furthermore, the distance between the boundary SR-1 of the sensing element region SR and the boundary PRR-1 of the optical identification region PRR may be less than or equal to 0.5 cm.

[0049] To ensure imaging contrast, in some embodiments, the refractive index (n1) of the light guide substrate 140 is greater than the refractive index (n4) of the first optical film 590. In this way, when light LL is incident from the light guide substrate 140 onto the first optical film 590 with the lower refractive index, and the angle of incidence θ (i.e., the angle between the light LL and the normal to surface 140S1 or surface 140S2) is greater than or equal to the critical angle corresponding to the interface between the light guide substrate 140 and the optical film 590, the light LL can undergo total internal reflection at the interface between the light guide substrate 140 and the optical film 590 with the lower refractive index, causing most of the light LL to be reflected back and transmitted via total internal reflection, thereby reducing transmission loss or ensuring imaging contrast. In some embodiments, the refractive index (n0) of air is close to the refractive index (n4) of the optical film 590.

[0050] Furthermore, to ensure reliability, the edge 560-1 of the adhesive layer 560 of the display device 50 may be adjacent to the edge 184-1 of the substrate 184, for example, in the normal direction of the substrate 184, the polarizing layer 182a of the display panel 180 overlaps with the adhesive layer 560. Because the overlap between the adhesive layer 560 of the display device 50 and the display panel 180 is large (e.g., the overlap area), the bonding between the light guide substrate 140 and the display panel 180 is enhanced, thereby improving reliability.

[0051] Please refer to Figure 6 , Figure 6 In another embodiment of this disclosure, along Figure 1 A cross-sectional view of a display device 60 drawn along section line A-A'. Figure 6 The architecture of the display device 60 shown is similar to Figure 5 The display device 50 shown uses the same symbols for the same components. The display device 60 also includes a second optical film 690 disposed on the light guide substrate 140. In some embodiments, the second optical film 690 is disposed on the surface 140S2 of the light guide substrate 140. In some embodiments, the refractive index (n1) of the light guide substrate 140 is greater than the refractive index (n5) of the second optical film 690. In this way, when the light source 120 emits light LL to the light guide substrate 140, the light LL can be transmitted within the light guide substrate 140 by total internal reflection, thereby reducing transmission loss or ensuring imaging contrast.

[0052] Furthermore, the second optical film 690 can further improve image quality. The second optical film 690 can be used to isolate dirt, such as a dirt SPT. The refractive index of the dirt SPT may be greater than or equal to the refractive index of the light guide substrate 140. In this case, light LL may not undergo total internal reflection at the interface between the light guide substrate 140 and the dirt SPT. Using the second optical film 690, the dirt SPT can ensure that the total internal reflection of light LL at the interface between the light guide substrate 140 and the optical film 690 does not affect the total internal reflection, thus ensuring total internal reflection transmission.

[0053] In some embodiments, the second optical film 690 may not overlap with the photosensing element 186. The distance between an edge 690-1 of the second optical film 690 away from the light source 120 and the boundary PRR-1 of the optical identification region PRR closest to the light source 120 may be less than or equal to 0.5 cm.

[0054] In summary, by designing the location of the adhesive layer boundary or setting an optical film on the light guide substrate, the light emitted by the light source has a better total internal reflection path in the light guide substrate before entering the optical recognition area. In this way, most of the light emitted by the light source can be incident on the sensing element area and received by multiple photosensitive elements in the sensing element area, thereby reducing transmission loss or ensuring imaging contrast.

[0055] The above description is merely an embodiment of this disclosure and is not intended to limit the scope of this disclosure. Various modifications and variations can be made to this disclosure by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A display device having a display area and a peripheral area, characterized by comprising: The display device comprises: a display panel, the display panel comprising: a first substrate comprising a driving circuit; a second substrate disposed opposite to the first substrate and comprising a filter layer; and a plurality of light sensing elements, the plurality of light sensing elements being located between the first substrate and the second substrate and in the display area, the plurality of light sensing elements overlapping the first substrate and the second substrate in a first direction; a light guide substrate having a first surface extending in a second direction and an opposite second surface, and disposed on the display panel, wherein the first direction is perpendicular to the second direction, along the first direction, the second substrate is located between the light guide substrate and the first substrate and overlaps, and the first surface is located between the second surface and the second substrate; a light source disposed on the first surface of the light guide substrate, and the plurality of light sensing elements receive light emitted by the light source, wherein the light source does not overlap the display panel in the first direction; and an adhesive layer disposed between the display panel and the light guide substrate; wherein the adhesive layer does not completely cover the display panel.

2. The display device of claim 1, wherein The display device has a sensing element area, the display panel has a normal direction, at least one boundary of the sensing element area extends a distance perpendicular to the normal direction, and the area within the distance is defined as an optical recognition area, wherein an edge of the adhesive layer is located within the optical recognition area, and the distance is equal to (H1+H2+H3)×tanθc, H1 is the thickness of the second substrate of the display panel, H2 is the sum of the thickness of the adhesive layer and the thickness of a polarizing layer of the display panel, H3 is the thickness of the light guide substrate, and θc is the critical angle corresponding to the interface between the light guide substrate and air.

3. The display device of claim 2, wherein, The display device further comprises: a first optical film disposed between the adhesive layer and the light guide substrate, the adhesive layer overlapping the plurality of light sensing elements, and the adhesive layer being located in the display area.

4. The display device of claim 3, wherein, The refractive index of the light guide substrate is greater than the refractive index of the first optical film.

5. The display device according to claim 3, wherein The distance between an edge of the first optical film away from the light source and a boundary of the optical recognition area closest to the light source is less than or equal to 0.5 cm.

6. The display device of claim 2, wherein The display device further comprises: a second optical film disposed on the light guide substrate.

7. The display device of claim 6, wherein The refractive index of the light guide substrate is greater than the refractive index of the second optical film.

8. The display device of claim 6, wherein, The distance between an edge of the second optical film away from the light source and a boundary of the optical recognition area is less than or equal to 0.5 cm.

9. The display device of claim 1, wherein The plurality of light sensing elements face the first surface.

10. The display device of claim 1, wherein A distance between an edge of the second substrate of the display panel and the plurality of light sensing elements is greater than or equal to W0+W1, where W0=H1xtanθc, W1=(H2+2xH3)xtanθc, H1 is a thickness of the second substrate of the display panel, H2 is a sum of a thickness of the adhesive layer and a thickness of a polarizing layer of the display panel, H3 is a thickness of the light guide substrate, and θc is a critical angle corresponding to an interface between the light guide substrate and air.

11. The display device of claim 1, wherein A distance between an edge of the adhesive layer and the plurality of light sensing elements is greater than or equal to W0, where W0=H1xtanθc, H1 is a thickness of the second substrate of the display panel, and θc is a critical angle corresponding to an interface between the light guide substrate and air.

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