Display device

Abstract

This disclosure relates to a display device, and more specifically, to a display device comprising: a plurality of light sources; a resin layer configured to cover the plurality of light sources; and a display panel disposed on the resin layer, including a display area and a non-display area, wherein the resin layer includes: a first region configured to overlap with the display area; and a second region configured to overlap with the non-display area, wherein a plurality of micropores are provided in at least a portion of the second region. Therefore, decomposition materials generated from the decomposition of the backlight unit and components surrounding the backlight unit in high-temperature and high-humidity environments can be discharged through the micropores.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2021-0128624, filed on September 29, 2021, with the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. Technical Field

[0003] This disclosure relates to a display device, and more particularly, to a display device that provides high reliability by minimizing brightness degradation in high-temperature and high-humidity environments. Background Technology

[0004] Liquid crystal displays (LCDs) are lightweight, thin, and require low power consumption, making them widely used. LCDs display images by adjusting the transmittance of liquid crystals using an electric field. To do this, LCDs adjust the transmittance on the screen in response to image signals applied to liquid crystals arranged in a matrix and multiple control switches to display the desired image. Because LCDs are not self-emissive display devices, they are equipped with a backlight unit that provides light to the rear surface of the liquid crystal display panel on which the image is displayed.

[0005] Light-emitting diodes (LEDs) are widely used as the light source for backlight units, and LEDs have the advantages of small size, high reliability and low power consumption.

[0006] Based on the arrangement of the light sources, backlight units can be broadly classified into direct-lit backlight units and edge-lit backlight units. Direct-lit backlight units are configured to emit light from multiple light sources mounted directly below the LCD panel, while edge-lit backlight units are configured to transmit light to the LCD panel from multiple light sources mounted on the sidewalls of a light guide plate. Direct-lit backlight units can improve the uniformity and brightness of the light emitted onto the panel and achieve excellent contrast through dimming drive. Summary of the Invention

[0007] Among the components in and around the backlight unit, some components susceptible to heat or moisture may decompose in high-temperature, high-humidity environments. This leads to brightness degradation as these components decompose as described above. In particular, the increased heat generated from multiple light sources during actual use of the display device can accelerate brightness degradation.

[0008] Furthermore, a resin layer is formed through molding to cover multiple light sources, thereby protecting the multiple light sources disposed in the backlight unit and planarizing these light sources. The decomposition material formed by component disassembly denatures the resin layer, leading to corrosion of the light sources that cause luminescence defects and deterioration of brightness.

[0009] An object to be achieved by the present disclosure is to provide a display device capable of achieving excellent reliability by suppressing deterioration of brightness in a high-temperature and high-humidity environment.

[0010] Another object to be achieved by the present disclosure is to suppress the resin layer from being denatured by a material that decomposes in a high-temperature and high-humidity environment. Still another object to be achieved by the present disclosure is to solve the problem of defects in the display device caused by the decomposed material.

[0011] The objects of the present disclosure are not limited to the above-mentioned objects, and those skilled in the art can clearly understand other objects not mentioned above from the following description.

[0012] According to an aspect of the present disclosure, a display device includes: a plurality of light sources; a resin layer provided to cover the plurality of light sources; and a display panel provided on the resin layer and including a display area and a non-display area, wherein the resin layer includes: a first area configured to overlap with the display area; and a second area configured to overlap with the non-display area, and wherein a plurality of fine holes are provided in at least a part of the second area.

[0013] According to another aspect of the present disclosure, a display device includes: a backlight unit including a light source and a planarization resin layer covering the light source; and a display panel provided on the resin layer and including a display area and a non-display area, wherein the resin layer includes: a first area configured to overlap with the display area, and a second area configured to overlap with the non-display area, wherein a plurality of fine holes are provided in the second area.

[0014] Other details of the exemplary embodiments are included in the detailed description and the drawings.

[0015] Since a plurality of fine holes are provided in the second area of the resin layer corresponding to the non-display area, the present disclosure provides breathability. Therefore, the decomposed material generated by the decomposition of the backlight unit and the components around the backlight unit in a high-temperature and high-humidity environment can be discharged through the fine holes without remaining in the backlight unit. Therefore, additional denaturation and corrosion caused by the decomposed material can be suppressed, and an increase in yellowing or haze can be minimized, thereby providing a display device with excellent reliability.

[0016] The effects according to the present disclosure are not limited to the above-exemplified contents, and more various effects are included in this specification. BRIEF DESCRIPTION OF THE DRAWINGS <00神仙道0056>The above and other aspects, features, and other advantages of the present disclosure will be more clearly understood from the following detailed description in conjunction with the drawings, in which:

[0018] Figure 1is an exploded perspective view of a display device according to an embodiment of the present disclosure;

[0019] Figure 2 is an enlarged cross-sectional view of a display device according to an embodiment of the present disclosure;

[0020] Figure 3 is a top view of a resin layer according to an embodiment of the present disclosure;

[0021] Figure 4 is a top view of a resin layer according to another embodiment of the present disclosure;

[0022] Figure 5 is a top view of a resin layer according to still another embodiment of the present disclosure; and

[0023] Figure 6 is a top view of a resin layer according to yet another embodiment of the present disclosure. Detailed Description of the Embodiments

[0024] The advantages and features of the present disclosure and the methods for realizing the advantages and features will be clear by referring to the exemplary embodiments described in detail below together with the attached Figure 1 drawings. However, the present disclosure is not limited to the exemplary embodiments disclosed herein, but will be implemented in various forms. The exemplary embodiments are provided only by way of example so that those skilled in the art can fully understand the disclosure content of the present disclosure and the scope of the present disclosure. Therefore, the present disclosure will be defined only by the scope of the appended claims.

[0025] The shapes, sizes, ratios, angles, numbers, etc. shown in the drawings for describing the exemplary embodiments of the present disclosure are only examples, and the present disclosure is not limited thereto. Throughout the specification, like reference numerals generally denote like elements. In addition, in the following description of the present disclosure, detailed descriptions of known related technologies may be omitted to avoid unnecessarily obscuring the subject matter of the present disclosure. Terms such as "comprising", "having", and "including" used herein generally intend to allow the addition of other components, unless these terms are used together with the term "only". Any reference to the singular form may include the plural form, unless otherwise clearly stated.

[0026] Even if not explicitly stated, components are interpreted to include a normal error range.

[0027] When using terms such as "on", "above", "below", and "adjacent" to describe the positional relationship between two parts, one or more parts may be located between these two parts, unless these terms are used together with the term "immediately" or "directly".

[0028] When a component or layer is positioned "on" another component or layer, the other layer or other component can be directly inserted onto or between that other component.

[0029] Although the terms "first," "second," etc., are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from other components. Therefore, in the technical concept of this disclosure, the first component referred to below can be the second component.

[0030] Throughout the specification, similar reference numerals generally denote similar elements.

[0031] The dimensions and thicknesses of each component shown in the accompanying drawings are illustrated for ease of description, and this disclosure is not limited to the dimensions and thicknesses of the components shown.

[0032] Features of the various embodiments of this disclosure may be combined or integrated with each other in part or in whole, and may be interlocked and operated in technically different ways, and the embodiments may be performed independently or in association with each other.

[0033] Unless otherwise specified throughout this specification, porosity (in %) is a value calculated from the free volume of the sample by positron annihilation lifetime spectroscopy (PAL). First, a polydimethylsiloxane sample (1 mm thick) was prepared as a control sample, and its free volume was measured using a Na-22 source as the positron generation source. Next, the moisture absorption of the sample was measured under room temperature and atmospheric pressure conditions. The moisture absorption was calculated using the following equation.

[0034]

[0035] (In this equation, m1 represents the weight of the dried sample, and m2 represents the weight of the sample with the maximum water absorption.)

[0036] The moisture absorption rate of the comparative samples was measured under identical conditions. The free volume was calculated by comparing the moisture absorption rates of the control sample and the comparative sample, based on the free volume value of the control sample.

[0037] Unless otherwise specified throughout the instruction manual, the water vapor transmission rate (unit: gcm) is as follows: -1 s -1 cmHg -1The value is measured using a standard gravimetric method based on ASTM E96 at room temperature and atmospheric pressure under conditions of 50% relative humidity. Specifically, the measurement is performed as follows: First, a circular sample with a diameter of 10 cm and a thickness of 1 mm is prepared and then placed at room temperature and atmospheric pressure for four days under conditions of 50% relative humidity. Next, the water vapor transmission rate with respect to the moisture gradient of the sample is measured using a permeation cup containing silica gel.

[0038] Unless otherwise specified throughout the instruction manual, the water contact angle is a value measured at room temperature (20°C to 25°C).

[0039] The present disclosure will be described below with reference to the accompanying drawings.

[0040] Figure 1 This is an exploded perspective view of a display device according to an embodiment of the present disclosure. Figure 2 This is an enlarged cross-sectional view of a display device according to an embodiment of the present disclosure. Figure 3 This is a top view of the resin layer according to an embodiment of the present disclosure.

[0041] First, refer to Figure 1 and Figure 2 The display device 100 according to an embodiment of the present disclosure includes a display panel 110, a printed circuit board 121, a light source 122, an optional reflector 130, a resin layer 140, an optional protective film 150, an optional diffuser 160, an optional optical sheet 170, and an optional bottom cover 180. The printed circuit board 121 (which is not the focus of this disclosure), the light source 122, the optional reflector 130, the resin layer 140, and the optional diffuser 160 can be configured as a single component and referred to as a backlight unit. Figure 2 In this context, the X-axis, Y-axis, and Z-axis correspond to the width, length, and thickness directions of the display panel or resin layer, respectively.

[0042] Display panel 110 is a panel configured to display images. Display panel 110 has a display area DA and a non-display area NDA. The display area DA is an area in which multiple pixels are provided for displaying an image. Pixels, including light-emitting areas, for displaying images can be provided in the display area DA, and driving elements for operating the pixels can be provided in the display area DA. As an example, the non-display area NDA surrounds the periphery of the display area DA, but the arrangement of the non-display area is not limited to this; for example, the non-display area can be provided on one or more sides of the display area. The non-display area NDA is an area covered by a light-shielding member and therefore substantially does not display images. Various lines, driver ICs, etc., for operating the pixels and driving elements provided in the display area DA can be provided in the non-display area NDA.

[0043] For example, the display panel 110 may be a liquid crystal display panel, which displays an image by using light emitted from a backlight unit to the display panel 110 and by adjusting the light transmittance while changing the arrangement of the liquid crystals included in the liquid crystal layer of the display panel 110. The display panel 110 includes a lower substrate, a liquid crystal layer disposed on the lower substrate, and an upper substrate disposed on the liquid crystal layer.

[0044] A pixel is defined by the intersection of multiple gate lines and multiple data lines on the lower substrate. Thin-film transistors are disposed at each intersection point of each pixel and connected to the pixel electrode formed in each pixel.

[0045] The common electrode, together with the pixel electrode, forms an electric field and controls the liquid crystal. Depending on the method used to control the alignment of the liquid crystal on the liquid crystal layer, the common electrode is formed on either the lower or upper substrate. For example, when controlling the liquid crystal in twisted nematic (TN) mode, vertical alignment (VA) mode, etc., the common electrode is disposed on the upper substrate, and the pixel electrode and the common electrode form a vertical electric field, thereby controlling the liquid crystal. When controlling the liquid crystal in edge field switching (FFS) mode, in-plane switching (IPS) mode, etc., the common electrode is disposed on the lower substrate, and the pixel electrode and the common electrode form a horizontal electric field, thereby controlling the liquid crystal.

[0046] A color filter and a black matrix are disposed on the upper substrate. Light emitted from the backlight unit is converted into beams of various colors as it passes through the liquid crystal layer and color filter between the lower and upper substrates. Thus, a full-color image is displayed. The black matrix can cover gate lines, data lines, or thin-film transistors disposed on the lower substrate, making them invisible.

[0047] A liquid crystal layer is disposed between an upper substrate and a lower substrate. An alignment layer can be disposed on the upper and lower parts of the liquid crystal layer and determines the initial arrangement orientation of the liquid crystal molecules. In addition, to suppress leakage of the liquid crystal layer, a side sealant can be formed along the edges of the upper and lower substrates.

[0048] In addition, although in Figure 1 Polarizing plates may be provided on the front and rear surfaces of the display panel 110, though they are not shown in the diagram.

[0049] A driving section 112 for operating the display panel 110 is provided along one side of the display panel 110. The driving section 112 includes various ICs such as gate driver ICs or data driver ICs and various driving circuits. The driving section 112 operates the display panel 110 by applying signals to the gate lines and data lines. In this case, the driving section 112 is electrically connected to the display panel 110 via a connecting member 111. For example, the connecting member 111 may be a chip-on-film (COF), a tape-on-carrier package (TCP), etc.

[0050] Therefore, when the thin-film transistor connected to the gate line in the display panel 110 is turned on in response to an on / off signal transmitted through the gate line, the image signal of the data line is transmitted to the corresponding pixel electrode. Thus, the arrangement of the liquid crystal is changed by the electric field generated between the pixel electrode and the common electrode, causing a change in transmittance.

[0051] The backlight unit provides light to the display panel 110. The backlight unit includes multiple light sources 122, a printed circuit board 121, a reflector 130, a resin layer 140, and a diffuser 160. The backlight unit is a direct-lit backlight unit, and the multiple light sources 122 are disposed on the lower side of the display panel 110.

[0052] In the case of a direct-lit backlight unit, multiple light sources 122 are directed towards the display panel 110, resulting in a relatively large number of light sources 122 compared to an edge-lit backlight unit. Furthermore, in a direct-lit backlight unit, the multiple light sources 122 can operate independently. Therefore, a direct-lit backlight unit can achieve excellent contrast through local dimming. Additionally, a direct-lit backlight unit can achieve high-brightness dynamic images through high dynamic range (HDR) driving, which increases the contrast between the bright and dark screens by further increasing the brightness of the light sources 122 corresponding to the bright area of ​​the screen.

[0053] When a voltage is applied to the light source 122, the light source 122 emits light. For example, multiple light sources 122 can each be a light-emitting diode (LED). The light source 122 as an LED can be a mini-LED with a size of several hundred micrometers or a micro-LED with a size of tens of micrometers.

[0054] The light source 122 emits light beams of various colors depending on the type of light source. Specifically, the light source 122 includes a red light source configured to emit red light, a green light source configured to emit green light, a blue light source configured to emit blue light, and a white light source configured to emit white light.

[0055] Multiple light sources 122 are mounted on a printed circuit board 121. The printed circuit board 121 is electrically connected to the multiple light sources 122 and applies voltage to the light sources 122. When the light source 122 is an LED, the light source 122 mounted on the printed circuit board 121 emits light by combining electrons and positive holes supplied from the first electrode 123a and the second electrode 123b.

[0056] Solder resist (SR) can be formed on the front and rear surfaces of the printed circuit board 121. The solder resist protects the circuitry formed on the printed circuit board 121. During the manufacturing process of the backlight unit, the solder resist suppresses solder bridges between adjacent circuits. For example, an upper solder resist PSRa can be formed on the front surface of the printed circuit board 121, and a lower solder resist PSRb can be formed on the rear surface of the printed circuit board 121. In this case, the upper solder resist PSRa can be patterned to form only in areas other than the area where the light source 122 is to be located.

[0057] A reflector 130 is disposed on a printed circuit board 121. The reflector 130 completely reflects light from the light source 122. The reflector 130 includes a plurality of through holes 131 through which the plurality of light sources 122 can pass respectively. The reflector 130 can be patterned to the same shape as the upper solder resist PSRa. That is, the reflector 130 is configured to cover the entire upper solder resist PSRa except for the plurality of light sources 122. Therefore, light directed toward the rear or side surface of the light source 122 but not toward the front surface on which the optical sheet 170 is disposed is reflected toward the optical sheet 170, thereby increasing the brightness of the light entering the display panel 110. In addition, even if only some of the plurality of light sources 122 are turned on, the reflector 130 can also suppress light diffusion and diffused halo phenomena.

[0058] The reflector 130 can be attached to the upper solder resist PSRa via an adhesive component.

[0059] The height from the top surface of the printed circuit board 121 to the uppermost point of the light source 122 can be lower than the height from the top surface of the printed circuit board 121 to the uppermost point of the reflector 130. That is, the top surface of the light source 122 does not need to protrude beyond the reflector 130. If the light source 122 protrudes beyond the reflector 130, the directional angle of the light may increase, potentially leading to light leakage. Specifically, similar to local dimming or HDR driving, when only some of the multiple light sources 122 are operating, the light emitted from the light source 122 with a wide directional angle can even diffuse into another area. Therefore, a halo effect may occur. Therefore, the top surface of the light source 122 is formed to be lower than the top surface of the reflector 130, so that the light source 122 does not protrude beyond the reflector 130, thereby suppressing the halo effect.

[0060] A resin layer 140 is disposed on the reflector 130. The resin layer 140 is thicker than the light source 122 and the reflector 130 to cover them. Furthermore, the resin layer 140 planarizes the surface on which the plurality of light sources 122 and the reflector 130 are disposed. That is, the resin layer 140 is configured to cover the entire surface on which the plurality of light sources 122 and the reflector 130 are disposed. Therefore, the resin layer 140 can physically / chemically protect the plurality of light sources 122. Additionally, the resin layer 140 can suppress light loss by minimizing the refractive index gradient along the optical path.

[0061] Additionally, the resin layer 140 fixes multiple light sources 122 and supports the optical sheet 170 located above the light sources 122. Therefore, an optical gap can be defined between the light sources 122 and the optical sheet 170. The optical gap is the distance between the optical sheet 170 and the light source 122. The optical gap is the region where light beams emitted from adjacent light sources 122 overlap and mix. Without ensuring the optical gap, spot mura may occur. That is, as the optical gap decreases, the light emitted from the light source 122 concentrates in the upper center of the light source 122, and the light beams emitted from adjacent light sources 122 cannot overlap, thus forming a dark area. Therefore, the resin layer 140 needs to have sufficient thickness to ensure the optical gap. Thus, the point-like light sources 122 are not visible, and the light beams emitted from adjacent light sources 122 overlap and function as a planar light source.

[0062] A protective film 150 is disposed on the resin layer 140. That is, the resin layer 140 is formed to fill the space between the protective film 150 and the plurality of light sources 122. The protective film 150 protects the resin layer 140. The protective film 150 may be made of a material with high transparency so as not to degrade the brightness of the light emitted from the light source 122. For example, the protective film 150 may be a polyethylene terephthalate film. However, this disclosure is not limited thereto.

[0063] The resin layer 140 can be made of a transparent silicone-based resin to prevent degradation of the brightness of the light emitted from the light source 122. Silicone-based resins can be readily used to form the desired shape and their physical properties can be easily adjusted. Therefore, the silicone-based resin can protect multiple light sources 122 and easily support the optical sheet 170. Furthermore, the silicone-based resin has a high refractive index of 1 or higher, thereby maintaining high efficiency in extracting light emitted from the light source 122.

[0064] The resin layer 140 has a first region AR1 and a second region AR2. The first region AR1 overlaps with the display region DA of the display panel 110. The second region AR2 overlaps with the non-display region NDA of the display panel 110. Therefore, the second region AR2 is formed to surround the first region AR1 in the same or similar manner as the non-display region NDA. That is, the second region AR2 has a frame shape to surround the first region AR1.

[0065] The resin layer 140 includes a plurality of micropores 141 in at least a portion of the second region AR2. Some components surrounding the resin layer 140 may decompose in high-temperature, high-humidity environments. In particular, components such as the upper solder resist PSRa and the protective film 150 made of organic materials may decompose due to heat or moisture. Various decomposition materials (water vapor, alcohols, acids, etc.) generated by the decomposition of organic materials increase yellowing and haze, which degrades brightness and display quality. In addition, if the decomposition materials remain in the backlight unit and are not removed, they corrode the light source 122, printed circuit board 121, etc., leading to light emission defects. Furthermore, the decomposition materials denature the resin layer 140, upper solder resist PSRa, protective film 150, etc., which degrades the reliability of the display device. In particular, when the display device is actually used, the heat generated from components such as the light source 122 increases. Therefore, decomposition and the denaturation and corrosion caused by the decomposition materials are accelerated, which further degrades reliability.

[0066] The display device 100 according to an embodiment of the present disclosure includes a plurality of micropores 141 in a second region AR2 of the resin layer 140, such that decomposition materials can be discharged through the micropores 141 without remaining in the backlight unit. Therefore, the degradation and corrosion of components caused by decomposition materials can be minimized.

[0067] For example, the average diameter of the multiple apertures 141 can be from 1 nm to 10 μm or from 1 nm to 500 nm. When the average diameter of the apertures 141 is within this range, high light extraction efficiency can be maintained, resulting in excellent brightness and display quality, and facilitating the removal of decomposed materials. If the average diameter of the apertures 141 is large enough to be several hundred micrometers or larger, brightness and reliability may deteriorate.

[0068] The aperture 141 can be formed only in the second region AR2 that overlaps with the non-display region DA. As described above, the resin layer 140 is made of a silicone-based resin with a high refractive index to maintain high brightness. However, the portion with the aperture 141 has a low refractive index. The light extraction efficiency may deteriorate due to the difference in refractive index between the portion with the aperture 141 and the portion without the aperture. Therefore, if the aperture 141 is formed in the first region AR1 that overlaps with the display region DA, the brightness and display quality of the display device 100 may deteriorate. In the display device 100 according to an embodiment of the present disclosure, the aperture 141 is formed in the second region AR2 of the resin layer 140, so that high display quality can be maintained without deterioration of display quality.

[0069] Reference Figure 3 Multiple apertures 141 can be uniformly distributed throughout the second region AR2, which has a frame shape. However, this disclosure is not limited thereto. Multiple apertures 141 can be formed along at least one of the four sides defining the second region AR2.

[0070] Figures 4 to 6 This is a top view of a resin layer having a plurality of pores 141 according to various embodiments. Figure 3 Similarly, in Figures 4 to 6 In the diagram, the X-axis and Y-axis directions correspond to the width and length directions of the resin layer, respectively.

[0071] Figure 4 This is a top view of a resin layer according to another embodiment of the present disclosure. (Refer to...) Figure 4 Multiple pores 141 can be formed along a single edge of the second region AR2 of the defining resin layer 240 that extends in the Y-axis direction (or X-axis direction).

[0072] Figure 5 This is a top view of the resin layer according to yet another embodiment of the present disclosure. (Refer to...) Figure 5 Multiple pores 141 can be formed along two of the four sides of the second region AR2 that define the resin layer 340, which face each other and extend in the Y-axis direction (or X-axis direction).

[0073] Figure 6 This is a top view of a resin layer according to another embodiment of the present disclosure. (Refer to...) Figure 6 Multiple pores 141 can be formed along two of the four sides of the second region AR2 that defines the resin layer 440, which face each other and extend in the Y-axis direction (or X-axis direction), and a single side that is perpendicular to these two sides and extends in the X-axis direction (or Y-axis direction).

[0074] As the number of micropores 141 formed in the second region AR2 of resin layers 140, 240, 340, and 440 increases, air permeability improves. Therefore, decomposed materials generated in high-temperature, high-humidity environments can be smoothly discharged. That is, when in... Figures 3 to 6 In the resin layer shown, multiple micropores 141 are distributed in a large area, having Figure 3 When the resin layer 140 with the structure shown is applied, the occurrence of defects caused by decomposed materials and the degradation of brightness can be suppressed more effectively. In addition, when the volume occupied by the multiple pores 141 remains the same, and when the multiple pores 141 are uniformly distributed throughout the entire second region AR2, the decomposed materials can be discharged more smoothly.

[0075] For example, the volume fraction of the region occupied by the micropores 141 in the resin layer 140 can be from 0.2 vol% to 2.0 vol%. Specifically, for example, the volume fraction of the region occupied by the micropores 141 can be from 1.0 vol% to 2.0 vol%. In this case, a sufficient number of micropores 141 are formed, allowing the decomposed material to be discharged more quickly and easily. Therefore, the reliability of the display device 100 is superior.

[0076] Since multiple pores 141 are formed in the second region AR2 of the resin layer 140, the first region AR1 and the second region AR2 can have different physical properties.

[0077] For example, the porosity of the second region AR2, which has multiple pores 141, is greater than that of the first region AR1. Specifically, for example, the porosity of the first region AR1 may be 12 vol% to 20 vol%, and the porosity of the second region AR2 may be 18 vol% to 30 vol%. For reference, since the first region AR1 is made of silicone resin, although no multiple pores 141 are formed in the first region AR1, the first region AR1 also has a predetermined level of porosity due to the properties of silicone resin. When the first region AR1 and the second region AR2 are made of silicone resin material with the same curability, the porosity of the second region AR2, which has multiple pores 141, is greater than that of the first region AR1, which does not have pores 141.

[0078] For example, the water vapor transmission rate of the second region AR2 can be 1.5 to 20 times that of the first region AR1. Because the second region AR2, with its multiple pores 141, has a high porosity as described above, the second region AR2 has a higher water vapor transmission rate than the first region AR1. Specifically, for example, the water vapor transmission rate of the first region AR1 can be 1.0 × 10⁻⁶. -6 gcm -1 s -1 cmHg -1Up to 4.0×10 -6 gcm -1 s -1 cmHg -1 Furthermore, the water vapor transmittance of AR2 in the second region can be 5.0 × 10⁻⁶. -6 gcm -1 s -1 cmHg -1 Up to 5.0×10 -5 gcm -1 s -1 cmHg -1 However, this disclosure is not limited thereto.

[0079] For example, the modulus of the second region AR2 can be less than that of the first region AR1. Specifically, the modulus of the first region AR1 can be from 30,000 Pa to 90,000 Pa, and the modulus of the second region AR2 can be from 1,000 Pa to 10,000 Pa.

[0080] Table 1 below shows the results of evaluating the reliability of the display devices based on the modulus of the resin layer. The display device 100 according to Example 1 includes a first region AR1 and a second region AR2, and the second region AR2 includes a resin layer 140 having a plurality of pores 141. In this case, the modulus of the first region AR1 is 40,000 Pa, while the modulus of the second region AR2 is 9,000 Pa. The display device according to Comparative Example 1-1 is not divided into a first region and a second region. The display device according to Comparative Example 1-1 includes a resin layer with a modulus of 50,000 kPa and without a plurality of pores. The display device according to Comparative Example 1-2 is not divided into a first region and a second region. The display device according to Comparative Example 1-2 includes a resin layer with a modulus of 30,000 Pa and without a plurality of pores. The reliability of each display device was evaluated using a luminous flux measuring device with an integrating sphere under conditions of 85°C and 85% relative humidity. The luminous flux was measured before the display devices were stored under high temperature and high humidity conditions. Table 1 shows the luminous flux retention over time under high temperature and high humidity conditions.

[0081] [Table 1]

[0082]

[0083] Referring to Table 1, it can be seen that the display device according to Example 1, which has multiple fine holes 141 formed in the second region AR2, has a high light flux retention rate and therefore excellent reliability.

[0084] However, in Comparative Example 1-1, which includes a resin layer with a high modulus, the initial luminous flux retention rate is optimal, but the luminous flux fails to remain high and deteriorates significantly, resulting in the lowest luminous flux retention rate. Compared to Example 1 or Comparative Example 1-2, the resin layer with a high modulus according to Comparative Example 1-1 exhibits better heat resistance and lower water vapor transmittance. Therefore, the entry of decomposition materials generated by peripheral components into the resin layer is suppressed, resulting in high initial reliability. However, it can be seen that the luminous flux retention rate decreases rapidly after 500 hours. This may mean that decomposition materials remain in the backlight unit without being expelled, leading to poor reliability from a long-term perspective.

[0085] Additionally, Comparative Examples 1-2 include a resin layer with a modulus less than that of the first region AR1 in Example 1. Resin layers with lower modulus have higher water vapor permeability, thus facilitating the removal of decomposed materials introduced into the resin layer, but their reliability is lower than that of Example 1.

[0086] In other words, in order to improve the long-term reliability of the display device 100, it is necessary to maintain the modulus of the resin layer 140 at an appropriate level, and it is necessary to form fine pores 141 in the second region AR2 to facilitate the discharge of decomposed materials.

[0087] The method of forming a resin layer 140 comprising a plurality of pores 141 in the second region AR2 will be described below.

[0088] For example, the resin layer 140 can be formed by the following method. First, a plurality of light sources 122, an upper solder resist PSRa, and a reflector 130 are formed on a printed circuit board 121. Next, a curing composition comprising an alkyl-terminated polydimethylsiloxane resin, a curing catalyst, and a foaming agent is prepared. Next, the curing composition is applied to a second region AR2 and pre-cured by light irradiation. The curing composition can be applied by a dispenser. However, this disclosure is not limited thereto. For example, pre-curing can be performed by emitting UV rays using a 365nm LED emitter. However, this disclosure is not limited thereto. Light sources with various wavelengths, such as metal halide lamps, mercury lamps, and 405nm LED emitters, can be used depending on the catalyst used. Next, thermal curing is performed. In this case, when the alkyl-terminated polydimethylsiloxane resin is cured by heat, the foaming agent is simultaneously foamed, thereby forming a plurality of pores 141. Thus, the second region AR2 is formed. For example, the foaming agent can be a hydrocarbon. The foaming agent decomposes during the thermal curing step, releasing gas, which allows the pores 141 to be formed. Foaming agents that can foam within a thermosetting temperature range can be used as foaming agents. For example, the foaming temperature of a foaming agent can be from 80°C to 120°C.

[0089] Additionally, to induce uniform foaming and suppress foaming of the foaming agent prior to the thermosetting step, a foaming agent with a core-shell structure can be used. For example, a foaming agent with a core-shell structure comprises a core made of hydrocarbons and a shell configured to surround the core. For example, the shell can be made of one or more materials selected from acrylonitrile, epoxy resin, and amide compounds. As another example, a foaming agent with a hollow structure having an empty core portion can be used. Fine pores 141 can be formed by utilizing thermal expansion during the thermosetting step to expel air from the core portion. When using a foaming agent with a core-shell structure, the thermosetting step can be carried out at a high temperature of 150°C to 200°C to suppress shell thermal decomposition and retain it in the resin layer 140.

[0090] After the second region AR2 is first formed as described above, a curing composition comprising an alkyl-terminated polydimethylsiloxane resin and a curing catalyst is applied to the first region AR1 and cured to form the first region AR1. Therefore, a resin layer 140 comprising the first region AR1 and the second region AR2 having a plurality of pores 141 can be formed.

[0091] As another example, the resin layer 140 can be formed by the following method.

[0092] First, a curing composition comprising an alkyl-terminated polydimethylsiloxane resin, a hydroxyl-terminated polydimethylsiloxane resin, and a curing catalyst is applied to the second region AR2, and preliminary curing is performed by light irradiation. The application of the curing composition and preliminary curing can be performed in the same manner as described above. Next, the preliminary cured material is heat-cured. For example, when the cured material is heated at a temperature of 60°C to 100°C, hydrogen gas is released through a reaction as illustrated in the example below, allowing the formation of pores 141. Thus, the second region AR2 having pores 141 is formed.

[0093] [Reaction Example]

[0094]

[0095] After manufacturing the second region AR2 as described above, the first region AR1 is formed in the same manner as described above. The steps for forming the first region AR1 are the same as those described above. Therefore, repeated descriptions will be omitted.

[0096] As another example, a resin layer 140 can be formed by using a silicone-based resin with a water contact angle of 80° to 100° by the following method.

[0097] First, a hydrophilic surface is formed on the surface of the reflector 130 where the second region AR2 is to be formed. For example, the hydrophilic surface can be made of a hydrophilic material such as water, alcohol, glycerol, or ethylene glycol. A curing composition comprising a curing catalyst and a silicone-based resin with a water contact angle of 80° to 100° is applied to the hydrophilic surface. Next, the curing composition is irradiated with UV rays and then thermo-cured at a temperature of 60° to 80°C, thereby forming the second region AR2 comprising a plurality of micropores 141. When the display device is formed by the above method, the micropores 141 have a uniform size and are uniformly distributed.

[0098] The first region AR1 is formed in the same manner as described above. Therefore, repeated descriptions will be omitted.

[0099] The bottom cover 180 houses and supports the backlight unit. The reflector 130 and the printed circuit board 121 in which multiple light sources 122 are embedded are located in the lower surface of the bottom cover 180. In addition, the bottom cover 180 can dissipate heat generated from the light sources 122.

[0100] at the same time, Figure 2 The bottom cover 180 and the backlight unit are shown spaced apart from each other. However, additional components can be further provided between the bottom cover 180 and the backlight unit. These additional components may include adhesive tape, adhesive material, shock-absorbing pads, etc. Mechanisms for modularizing the bottom cover 180, the backlight unit, and the display panel 110 may also be provided.

[0101] Multiple optical sheets 170 diffuse or collect light emitted from multiple light sources 122, allowing light with a uniform surface shape to enter the display panel 110. The multiple optical sheets 170 may include diffusers, at least one light-collecting sheet, etc.

[0102] A diffuser plate 160 is disposed between a plurality of optical sheets 170 and a resin layer 140. The diffuser plate 160 diffuses light emitted from a plurality of light sources 122 and enables light to enter the plurality of optical sheets 170 with high efficiency.

[0103] As needed, an optical functional film can be selectively disposed between the diffuser plate 160 and the resin layer 140. For example, the optical functional film can be an anti-mura film. However, this disclosure is not limited thereto. The anti-mura film suppresses glare or scattering of light emitted from the light source 122 and suppresses the visibility of the reflector plate 130. Therefore, it is possible to improve light extraction efficiency and provide excellent display quality.

[0104] The effects of the present disclosure described above will be described in more detail below with reference to examples and comparative examples. However, the following examples are for illustrative purposes only, and the scope of the present disclosure is not limited to the following examples.

[0105] [Example 2-1]

[0106] A reflector is formed on a printed circuit board on which a miniature LED array is mounted, and then molded to form a reflector such as... Figure 3 The diagram shows a silicone resin layer (175 mm wide, 400 mm long, and 450 μm to 500 μm thick). When forming a second region (less than 1 mm wide) of the resin layer, fine pores are formed throughout the second region by foaming a foaming agent. A display device is manufactured by stacking a protective film, a diffuser plate, an optical sheet, and a display panel on the resin layer.

[0107] [Examples 2-2 to 2-8]

[0108] As shown in Table 2 below, the display devices according to Examples 2-2 to 2-8 were manufactured in the same manner as in Example 2-1, except that the area in which the pores are formed in the second region of the resin layer was changed.

[0109] For reference, in Table 2 below, "1X" means that a pore is formed along a single edge extending in the X-axis direction among the four edges of the second region defining the resin layer, "2X" means that a pore is formed along two edges extending in the X-axis direction, "1Y" means that a pore is formed along a single edge extending in the Y-axis direction, and "2Y" means that a pore is formed along two edges extending in the Y-axis direction.

[0110] [Comparative Example 2]

[0111] Except for omitting the step of forming fine pores by using a foaming agent in the resin layer formation step, a display device with the same components as those in Example 2-1 was manufactured.

[0112] [Experimental Example]

[0113] The reliability of the display devices according to Examples 2-1 to 2-8 and the display device according to Comparative Example 2 was evaluated. First, the initial luminous flux of each display device was measured using an integrating sphere and a luminous flux meter. Next, each display device was stored in a room with a temperature of 85°C and a relative humidity of 85%, and the luminous flux was measured at 100 hours, 500 hours, and 1000 hours using the same equipment. The initial luminous flux was set to 100%, and the luminous flux retention rate was calculated over time. The results are shown in Table 2 below.

[0114] [Table 2]

[0115]

[0116] Referring to Table 2, it can be seen that the display device of Comparative Example 2, which includes a resin layer without pores, has a good light flux retention rate before 100 hours, but the light flux retention rate drops rapidly, resulting in a lower reliability than Examples 2-1 to 2-8.

[0117] In contrast, the display devices of Examples 2-1 to 2-8, which include micropores in at least a portion of the second region of the resin layer, are superior to Comparative Example 2. Furthermore, referring to Table 2, it can be seen that the wider or larger the area where micropores are formed, the better the reliability. In particular, it can be seen that in the case of Example 2-1, where micropores are formed throughout the entire second region, even after the display device has been stored under high temperature and high humidity conditions for 1,000 hours, the luminous flux remains at a significantly high level without serious degradation.

[0118] However, it can be seen that Examples 2-5 and 2-6 do not conform to the trend. Specifically, Example 2-6 is an example of forming a pore along a single edge in the X-axis direction and a single edge in the Y-axis direction. Example 2-5 is an example of forming a pore along two parallel edges in the X-axis direction. Because in the resin layer, in the Y-axis direction ( Figures 3 to 6 The length of the perpendicular side is greater than that of the side along the X-axis. Figures 3 to 6 The length of the horizontal side is longer, so the area where the micro-holes are formed in Example 2-6 is larger than that in Example 2-5. However, it can be seen that the luminous flux retention rate of Example 2-5 is slightly higher. Therefore, it can be seen that forming multiple micro-holes, considering not only the formation rate of micro-holes in the second region, is effective in improving reliability, but also that uniformly distributing the micro-holes is effective in improving reliability. This can be estimated because the decomposition material is not only formed in specific areas, but also randomly formed in a high-temperature, high-humidity environment. That is, the decomposition material is randomly generated in the backlight unit. Therefore, it is necessary to uniformly distribute the micro-holes in the second region to facilitate the discharge of the decomposition material.

[0119] Exemplary embodiments of this disclosure can also be described as follows:

[0120] According to one aspect of this disclosure, a display device includes: an optional printed circuit board; a plurality of light sources (which may be disposed on the optional printed circuit board); an optional reflector disposed on the printed circuit board and having a plurality of through holes respectively penetrated by the plurality of light sources; a resin layer disposed to cover the plurality of light sources and optionally to cover the reflector and optionally configured to planarize the surface; and a display panel disposed on the resin layer and including a display area and a non-display area optionally configured to surround the display area, wherein the resin layer includes: a first area configured to overlap with the display area; and a second area configured to overlap with the non-display area, and wherein a plurality of micropores are provided in at least a portion of the second area.

[0121] The average diameter of the pores can range from 1 nm to 10 μm.

[0122] The porosity of the second region can be greater than that of the first region, where the porosity of the first region can be 12% to 20% by volume, and the porosity of the second region can be 18% to 30% by volume.

[0123] The water vapor transmission rate of the second zone can be 1.5 to 20 times that of the first zone.

[0124] The modulus of the first region can be from 30,000 Pa to 90,000 Pa, and the modulus of the second region can be from 1,000 Pa to 10,000 Pa.

[0125] The resin layer can be made of silicone-based resin.

[0126] The first region of the resin layer may be made of alkyl-terminated polydimethylsiloxane resin, and the second region of the resin layer may be made of alkyl-terminated polydimethylsiloxane resin and hydroxyl-terminated polydimethylsiloxane resin.

[0127] The first region of the resin layer may be made of alkyl-terminated polydimethylsiloxane resin, and the second region of the resin layer may be made of alkyl-terminated polydimethylsiloxane resin and a foaming agent.

[0128] The first region of the resin layer may be made of an alkyl-terminated polydimethylsiloxane resin, and the second region of the resin layer may be made of a silicone resin with a water contact angle of 80° to 100°.

[0129] The display device may also include: an optional optical sheet disposed between the resin layer and the display panel; and an optional protective film disposed between the resin layer and the optical sheet, wherein the resin layer may fill the space between a plurality of light sources and the protective film.

[0130] The height from the top of the printed circuit board to the light source can be lower than the height from the top of the printed circuit board to the reflector.

[0131] According to another aspect of this disclosure, the display device includes: a backlight unit including a light source and a planarized resin layer covering the light source; and a display panel disposed on the resin layer and including a display area and a non-display area, wherein the resin layer includes: a first area configured to overlap with the display area and a second area configured to overlap with the non-display area, wherein a plurality of micropores are provided in the second area.

[0132] Multiple pores can be evenly distributed throughout the second region.

[0133] Although exemplary embodiments of the present disclosure have been described in detail with reference to the accompanying drawings, the present disclosure is not limited thereto, and the present disclosure may be embodied in many different forms without departing from the technical concept of the present disclosure. Therefore, exemplary embodiments of the present disclosure are provided for illustrative purposes only and are not intended to limit the technical concept of the present disclosure. The scope of the technical concept of the present disclosure is not limited thereto. Therefore, it should be understood that the above exemplary embodiments are illustrative in all respects and do not limit the present disclosure. The scope of protection of the present disclosure should be interpreted based on the appended claims, and all technical concepts within the equivalent scope thereof should be construed as falling within the scope of the present disclosure.

Claims

1. A display device, comprising: Multiple light sources; A resin layer is configured to cover the plurality of light sources; as well as A display panel is disposed on the resin layer and includes a display area and a non-display area. The resin layer includes: A first region, which is configured to overlap with the display region; and The second region is configured to overlap with the non-display region, and In this configuration, at least a portion of the second region contains a plurality of fine pores, while the first region does not contain any fine pores. Wherein, the porosity of the second region is greater than that of the first region, and The water vapor transmission rate of the second region is greater than that of the first region.

2. The display device according to claim 1, wherein, The average diameter of the pores is 1 nm to 10 μm.

3. The display device according to claim 1, wherein, The porosity of the first region is 12% to 20% by volume, and the porosity of the second region is 18% to 30% by volume.

4. The display device according to claim 1, wherein, The water vapor transmission rate of the second region is 1.5 to 20 times that of the first region.

5. The display device according to claim 1, wherein, The modulus of the first region is from 30,000 Pa to 90,000 Pa, and the modulus of the second region is from 1,000 Pa to 10,000 Pa.

6. The display device according to claim 1, wherein, The resin layer is made of silicone-based resin.

7. The display device according to claim 6, wherein, The first region of the resin layer is made of alkyl-terminated polydimethylsiloxane resin, and the second region of the resin layer is made of alkyl-terminated polydimethylsiloxane resin and hydroxyl-terminated polydimethylsiloxane resin.

8. The display device according to claim 6, wherein, The first region of the resin layer is made of alkyl-terminated polydimethylsiloxane resin, and the second region of the resin layer is made of alkyl-terminated polydimethylsiloxane resin and a foaming agent.

9. The display device according to claim 6, wherein, The first region of the resin layer is made of alkyl-terminated polydimethylsiloxane resin, and the second region of the resin layer is made of silicone resin with a water contact angle of 80° to 100°.

10. The display device according to claim 1, further comprising: An optical element is disposed between the resin layer and the display panel; as well as A protective film is disposed between the resin layer and the optical sheet. The resin layer fills the space between the plurality of light sources and the protective film.

11. The display device according to claim 1, further comprising: A printed circuit board, wherein the plurality of light sources are disposed on the printed circuit board.

12. The display device according to claim 11, further comprising: A reflector is disposed on the printed circuit board and has a plurality of through holes through which the plurality of light sources penetrate.

13. The display device according to claim 12, wherein, The resin layer is configured to cover the plurality of light sources and the reflector, and is configured to flatten the surface.

14. The display device according to claim 12, wherein, The height from the printed circuit board to the top of the light source is lower than the height from the printed circuit board to the top of the reflector.

15. The display device according to claim 12, wherein, A solder resist is applied to the surface of the printed circuit board on which the plurality of light sources are disposed. The reflector covers the solder resist, and the reflector and the solder resist are patterned into the same shape.

16. The display device according to claim 1, wherein, The non-display area is configured to surround the display area.

17. A display device, comprising: A backlight unit includes: a light source, and a planarizing resin layer covering the light source; and A display panel is disposed on the resin layer and includes a display area and a non-display area. The resin layer includes: a first region configured to overlap with the display region; and a second region configured to overlap with the non-display region, wherein the second region has a plurality of micropores and the first region does not have micropores. Wherein, the porosity of the second region is greater than that of the first region, and The water vapor transmission rate of the second region is greater than that of the first region.

18. The display device according to claim 17, wherein in, The multiple pores are evenly distributed throughout the second region.

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