Display device

Abstract

The present invention discloses a display device comprising a first display panel, a second display panel, and a light-absorbing layer. The first display panel and the second display panel each comprise a circuit board, a plurality of light-emitting elements, and an optical film. The light-emitting elements are disposed between the circuit board and the optical film and are electrically connected to the circuit board. The first display panel and the second display panel have a joint. The light-absorbing layer covers the side edge of the optical film of one of the first display panel and the second display panel at the joint.

Description

Technical Field

[0001] The present invention relates to a display device, and in particular to a spliced ​​display device. Background Art

[0002] As the applications of display devices continue to diversify, large-scale billboards used to display public information or advertisements are becoming increasingly popular in exhibition halls and department stores. To reduce the installation and maintenance costs of large billboards, tiled displays, constructed by splicing multiple display panels, have become a common installation method for these large-scale billboards. Because LED panels have narrower bezels, image discontinuities (such as dark lines) at the spliced ​​joints are minimal, or even invisible, making them the mainstream choice for tiled panels.

[0003] In order to improve the dark-state performance of such spliced ​​display devices, a technology for attaching a blackened optical film to the LED panel has been proposed. In order to meet the size and appearance of different spliced ​​display devices, the display panels used for splicing need to be cut. However, during the cutting process, it is easy for such optical films to produce burrs at the cut points, affecting the overall visual effect of the spliced ​​display device, for example, in the dark state. In addition, when the spliced ​​display device needs to be reworked, the adhesive layer used to attach the optical film is prone to glue pulling with the adhesive layer of the adjacent optical film, increasing the difficulty of rework. Summary of the Invention

[0004] The present invention provides a display device having excellent image continuity at a splicing portion and excellent dark state performance.

[0005] The display device of the present invention includes a first display panel, a second display panel, and a light-absorbing layer. The first display panel and the second display panel each have a circuit board, a plurality of light-emitting elements, and an optical film. The light-emitting elements are disposed between the circuit board and the optical film and are electrically connected to the circuit board. The first display panel and the second display panel have a joint. The light-absorbing layer covers the side edge of the optical film of one of the first display panel and the second display panel at the joint.

[0006] Based on the above, in a display device according to one embodiment of the present invention, a light-absorbing layer is provided at the joint of two display panels. By covering the side edge of the optical film of one display panel at the joint, this light-absorbing layer can significantly reduce the visibility of the joint in the dark state, thereby improving the display quality of the joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a schematic top view of a display device according to a first embodiment of the present invention;

[0008] Figure 2 yes Figure 1 A schematic cross-sectional view of a display device;

[0009] Figure 3 yes Figure 2 A cross-sectional schematic diagram of another modified embodiment of a display device;

[0010] Figure 4 is a schematic cross-sectional view of a display panel and a light absorbing layer according to a second embodiment of the present invention;

[0011] Figure 5 is a schematic cross-sectional view of a display panel and a light absorbing layer according to a third embodiment of the present invention;

[0012] Figure 6 is a schematic cross-sectional view of a display panel and a light absorbing layer according to a fourth embodiment of the present invention;

[0013] Figure 7 is a schematic cross-sectional view of a display panel and a light absorbing layer according to a fifth embodiment of the present invention;

[0014] Figure 8 is a schematic cross-sectional view of a display panel and a light absorbing layer according to a sixth embodiment of the present invention;

[0015] Figure 9 is a schematic cross-sectional view of a display panel and a light absorbing layer according to a seventh embodiment of the present invention;

[0016] Figure 10 is a schematic cross-sectional view of a display panel and a light absorbing layer according to an eighth embodiment of the present invention;

[0017] Figure 11 FIG. 1 is a schematic cross-sectional view of a display panel and a light absorbing layer according to a ninth embodiment of the present invention.

[0018] Explanation of symbols

[0019] 10, 10A: Display device

[0020] 100: Circuit board

[0021] 100s, 220s, 260s: surface

[0022] 130, 130A, 130B: Adhesive layer

[0023] 130e, 310e, 320e, 130e", 310e", 320e", 260e, 150e, 100e: side edge

[0024] 135: Light-absorbing particles

[0025] 150:Reflective layer

[0026] 200: packaging structure

[0027] 200t: Upper surface

[0028] 205: Circuit substrate

[0029] 220: first encapsulation layer

[0030] 250, 250A, 250B, 250C, 250D, 250E, 250G, 250H: light-absorbing layer

[0031] 250p1, 250p1': Part 1

[0032] 250p2, 250p2”: Part 2

[0033] 260: Second encapsulation layer

[0034] 300, 310, 320, 310A, 320A: Optical film

[0035] DP, DP1, DP2, DP-A, DP-B, DP-C, DP-D, DP-E, DP-F, DP-G, DP-H: Display Panel

[0036] d1, d2: distance

[0037] LED1, LED2, LED3, LED1”, LED2”, LED3”: light-emitting elements

[0038] PU, PU-A: Pixel Unit

[0039] t, t': thickness

[0040] TP:Splicing

[0041] A-A': section line DETAILED DESCRIPTION

[0042] As used herein, "about," "approximately," "substantially," or "substantially" include the stated value and the mean value within an acceptable deviation range for the particular value as determined by one of ordinary skill in the art, taking into account the measurement in question and the particular amount of error associated with the measurement (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations of the stated value, or within, for example, ±30%, ±20%, ±15%, ±10%, ±5%. Furthermore, as used herein, "about," "approximately," "substantially," or "substantially" can be used to select a more acceptable range of deviations or standard deviations depending on the property being measured, cut, or other property, and may not apply to all properties without a single standard deviation.

[0043] In the accompanying drawings, the thickness of layers, films, panels, regions, etc. is exaggerated for clarity. It should be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "connected to" another element, it can be directly on or connected to the other element, or intermediate elements may also exist. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element, there are no intermediate elements. As used herein, "connected" can refer to physical and / or electrical connections. Furthermore, "electrical connection" can mean the presence of other elements between two elements.

[0044] Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals are used in the drawings and the description to refer to the same or like parts.

[0045] Figure 1 FIG. 1 is a schematic top view of a display device according to a first embodiment of the present invention. Figure 2 yes Figure 1 A schematic cross-sectional view of a display device. Figure 2 Corresponding to Figure 1 Section line A-A'. Figure 3 yes Figure 2 Please refer to the cross-sectional diagram of another variant embodiment of the display device. Figure 1 and Figure 2 The display device 10 may be formed by splicing a plurality of display panels DP. That is, the display device 10 is a spliced ​​display device. For example, in this embodiment, the display device 10 may be formed by splicing a first display panel DP1 and a second display panel DP2, and has a splicing point TP.

[0046] Each of the first display panel DP1 and the second display panel DP2 includes a circuit board 100, a plurality of pixel units PU, and an optical film 300. The pixel units PU are disposed on and electrically connected to the circuit board 100. The optical film 300 covers the pixel units PU. In other words, the pixel units PU are disposed between the circuit board 100 and the optical film 300.

[0047] In this embodiment, the circuit board 100 is, for example, a printed circuit board (PCB), but is not limited thereto. In other embodiments, the circuit board 100 may also be a combination of a glass substrate and a pixel circuit layer, wherein the pixel circuit layer is formed on the glass substrate using a semiconductor manufacturing process and may include active components (such as thin film transistors) and various signal lines (such as data lines, scan lines, or power lines), but is not limited thereto.

[0048] The display panel DP's circuit board 100 may be arrayed with a plurality of pixel units PU. Each pixel unit PU may be composed of a plurality of light-emitting elements, such as a first light-emitting element LED1, a second light-emitting element LED2, and a third light-emitting element LED3. For example, in this embodiment, these light-emitting elements may be bonded to a circuit substrate 205 and covered with a first encapsulating adhesive layer 220 to form a package structure 200, but this is not limiting. Preferably, the light transmittance of the first encapsulating adhesive layer 220 is greater than 50%.

[0049] The material of the first encapsulating adhesive layer 220 may include a transparent polymer or a translucent polymer, such as a soft gel, an elastomer, or a resin, wherein the resin may be epoxy resin, silicone, or an epoxy-silicone hybrid resin. Furthermore, in some embodiments, the first encapsulating adhesive layer 220 may be doped with an organic filler or an inorganic filler, wherein the filler material may be selected from the group consisting of silicon dioxide (SiO2), titanium dioxide (TiO2), aluminum oxide (Al2O3), yttrium oxide (Y2O3), carbon black, sintered diamond powder, asbestos, glass, and combinations thereof.

[0050] For example, the package structure 200 may be a plastic leaded chip carrier (PLCC) package structure, a surface mounted device (SMD), a molding package structure, or other suitable package structures.

[0051] In this embodiment, the circuit substrate 205 may be provided with a plurality of conductive pads (not shown) on a side surface facing the carrier 100, and all the light-emitting elements LED1 to LED3 arranged on the other side surface may be electrically connected to the plurality of conductive pads via the connecting circuits (not shown) within the circuit substrate 205. Correspondingly, a side surface of the circuit board 100 may be provided with a plurality of bonding pads (not shown) for bonding the package structure 200, and the plurality of conductive pads may be respectively bonded to these bonding pads on the circuit board 100. These bonding pads may be electrically connected to different parts of the driving circuit (not shown) on the circuit board 100 to perform individual electrical operations. That is, the package structure 200 can be electrically connected to the circuit board 100 via the bonding relationship between the conductive pads on the circuit substrate 205 and the bonding pads on the circuit board 100.

[0052] To increase the light energy utilization efficiency of the display panel DP, a reflective layer 150 is further provided on the circuit board 100. The reflective layer 150 can be disposed on the surface 100s of the circuit board 100 located between the plurality of package structures 200. That is, the reflective layer 150 does not overlap the package structures 200 along the normal direction of the surface 100s of the circuit board 100.

[0053] In this embodiment, the display panel DP is illustrated as having two optical films 300, namely, optical film 310 and optical film 320, but the present invention is not limited thereto. For example, the two optical films may be attached to the top surfaces 200t of the plurality of packaging structures 200 via an adhesive layer 130. The adhesive layer 130 may be made of, for example, optically clear adhesive (OCA), optically pressure-sensitive adhesive (PSA), silicone adhesive, polyurethane reactive (PUR) adhesive, polyurethane (PU) adhesive, or other suitable optical-grade adhesive materials.

[0054] The optical film 300 can be selected from an anti-glare (AG) film, an anti-reflection (AR) film, a circular polarizer, a quarter-wave plate, a microstructured film, or a combination thereof. For example, in this embodiment, the optical film 310 can be an AG film, and the optical film 320 can be a circular polarizer, but the present invention is not limited thereto.

[0055] Furthermore, the display device 10 also includes a light-absorbing layer 250 disposed at the joint TP between the first display panel DP1 and the second display panel DP2. Specifically, the optical film 310, the optical film 320, and the adhesive layer 130 of the display panel DP have side edges 310e, side edges 320e, and side edges 130e, respectively, at the joint TP, and these side edges are all covered with the light-absorbing layer 250. Since the side edges of the optical film 300 will generally produce burrs due to the cutting process, when the display device is operating in a dark state, these burrs can be easily perceived by the human eye, and the presence of the joint TP can be detected. Therefore, using the light-absorbing layer 250 to cover the side edges of the optical film produced by cutting can significantly reduce the visibility of the burrs in a dark state, thereby helping to improve the splicing display quality of the display device 10.

[0056] In this embodiment, the optical density (OD) of the light absorbing layer 250 may be greater than or equal to 0.1 to effectively reduce the visibility of the seam between two adjacent display panels DP. From another perspective, the optical density of the light absorbing layer 250 may be less than or equal to 2.7 to ensure the invisibility of the light absorbing layer 250 when the display device 10 is in the bright state. In a preferred embodiment, the optical density of the light absorbing layer 250 is greater than or equal to 0.7 and less than or equal to 2.5. Materials for the light absorbing layer 250 include, for example, epoxy resin, polymethacrylate (PMMA), carbon black-doped silicone, other suitable polymer materials, pure ink or paint, etc.

[0057] Notably, in this embodiment, the light-absorbing layer 250 extends to and covers the side edge 130e of the adhesive layer 130. This prevents the adhesive layer 130 of one display panel DP from contacting the adhesive layer 130 of another display panel DP during rework, thereby improving the reworkability of the display panels DP being spliced. Furthermore, the light-absorbing layer 250 serves as a buffer layer to prevent damage to the two display panels DP caused by side edge collision during splicing.

[0058] It is particularly noted that in this embodiment, the optical film 300 of the first display panel DP1 and the second display panel DP2 are both covered with a light absorbing layer 250 at the side edges of the joint TP. For example, the light absorbing layer 250 has a thickness t along a direction perpendicular to the side edge of the optical film, and the thickness t may be in the range of 1 micron to 50 microns. Preferably, the thickness t may be in the range of 10 microns to 30 microns. However, the present invention is not limited thereto. Please refer to Figure 3In another embodiment, the light absorbing layer 250A of the display device 10A may also only cover the side edge of the optical film layer of one of the display panels DP (e.g., the first display panel DP1) at the splicing point TP, while the optical film layer of the other display panel DP (e.g., the second display panel DP2) is at the splicing point TP. Therefore, the thickness t" of the light absorbing layer 250A can be relative to Figure 2 The thickness t of the light absorbing layer 250 is set to be thicker, but the present invention is not limited thereto.

[0059] Some other embodiments will be listed below to illustrate the present invention in detail, wherein the same components will be marked with the same symbols, and the description of the same technical content will be omitted. For the omitted parts, please refer to the above embodiments and will not be repeated below.

[0060] Figure 4 Schematic cross-sectional view of the display panel and the light absorbing layer according to the second embodiment of the present invention. Figure 4 , different from Figure 2 The display panel DP, in this embodiment, is used for the display panel DP-A of the splicing display device, and its optical film 310A, optical film 320A and adhesive layer 130A are respectively used for splicing side edges 310e", side edges 320e", and side edges 130e", which are surfaces inclined relative to the upper surface 200t of the packaging structure 200.

[0061] By using the light-absorbing layer 250 to cover the side edge 310e″ of the optical film 310A, the side edge 320e″ of the optical film 320A, and the side edge 130e″ of the adhesive layer 130A, it is possible not only to significantly reduce the visibility of the burrs of the optical film caused by cutting in the dark state, but also to prevent the adhesive layer 130A of the display panel DP-A from contacting the adhesive layer 130A of another part of the display panel DP-A during rework, thereby causing glue to be pulled. In other words, it helps to improve the splicing display quality of the display device and improve the reworkability of the splicing display panel DP-A.

[0062] Since the other components and relative configuration relationships of this embodiment are similar to Figure 2 For detailed description of the display device 10, please refer to the relevant paragraphs of the aforementioned embodiment, which will not be repeated here.

[0063] Figure 5 Schematic cross-sectional view of the display panel and the light absorbing layer according to the third embodiment of the present invention. Figure 5 , different from Figure 2In this embodiment, the display panel DP used for the tiled display device may optionally include a second encapsulating adhesive layer 260 disposed between the encapsulating structure 200 and the optical film 300. For example, the second encapsulating adhesive layer 260 may cover the surface 220s of the first encapsulating adhesive layer 220 and the reflective layer 150, and the optical film 300 is attached to the surface 260s of the second encapsulating adhesive layer 260 via the adhesive layer 130. Preferably, the light transmittance of the second encapsulating adhesive layer 260 is greater than 10%.

[0064] Specifically, in this embodiment, the distance d1 between the surface 220s (i.e., the first surface) of the first encapsulating adhesive layer 220 and the surface 100s (i.e., the third surface) of the circuit board 100 may be greater than the distance d2 between the surface 260s (i.e., the second surface) of the second encapsulating adhesive layer 260 and the surface 100s of the circuit board 100. In other words, the surface 260s of the second encapsulating adhesive layer 260 may be higher than the surface 220s of the first encapsulating adhesive layer 220 relative to the surface 100s of the circuit board 100. However, the present invention is not limited to this. According to other embodiments (not shown), the surface 260s of the second encapsulating adhesive layer 260 may also be aligned with the surface 220s of the first encapsulating adhesive layer 220 of the package structure 200. In other words, the aforementioned distance d1 may also be equal to the aforementioned distance d2.

[0065] It is particularly noteworthy that the light absorbing layer 250B of this embodiment does not extend to the side edge 130e of the adhesive layer 130. Using the light absorbing layer 250B to cover the side edge of the optical film produced by cutting can significantly reduce the visibility of the burrs in the dark state, which helps to improve the splicing display quality of the display device. Since the other components and relative configuration relationships of this embodiment are similar to Figure 2 For detailed description of the display device 10, please refer to the relevant paragraphs of the aforementioned embodiment, which will not be repeated here.

[0066] Figure 6 FIG is a cross-sectional view of a display panel and a light absorbing layer according to a fourth embodiment of the present invention. Figure 6 , different from Figure 5 In this embodiment, the light absorbing layer 250C further extends to and covers the side edge 130e of the adhesive layer 130 and part of the side edge 260e of the second encapsulating adhesive layer 260. Therefore, it can also prevent the adhesive layer 130 of the display panel DP-C from contacting with the adhesive layer 130 of another display panel DP-C during rework, thereby helping to improve the reworkability of the spliced ​​display panel DP-C. Since the other components and relative configuration relationships of this embodiment are similar to Figure 2 For detailed description of the display device 10, please refer to the relevant paragraphs of the aforementioned embodiment, which will not be repeated here.

[0067] Figure 7FIG is a cross-sectional view of a display panel and a light absorbing layer according to a fifth embodiment of the present invention. Figure 7 , different from Figure 6 In this embodiment, the light absorbing layer 250D further extends to and covers the side edge 150e of the reflective layer 150 and a portion of the side edge 100e of the circuit board 100.

[0068] By using the light absorbing layer 250D to cover the side edge 310e of the optical film 310, the side edge 320e of the optical film 320, and the side edge 130e of the adhesive layer 130, in addition to significantly reducing the visibility of the burrs of the optical film caused by cutting in the dark state, it can also prevent the adhesive layer 130 of the display panel DP-D from contacting the adhesive layer 130 of another display panel DP-D during rework, thereby causing glue to be pulled. In other words, it helps to improve the splicing display quality of the display device and improve the reworkability of the splicing display panel DP-D. Since the other components and relative configuration relationships of this embodiment are similar to Figure 2 For detailed description of the display device 10, please refer to the relevant paragraphs of the aforementioned embodiment, which will not be repeated here.

[0069] Figure 8 FIG is a cross-sectional view of a display panel and a light absorbing layer according to a sixth embodiment of the present invention. Figure 8 , different from Figure 5 In this embodiment, the display panel DP-E does not have Figure 5 The optical film 320 is formed by cutting the optical film 310, and the light absorbing layer 250E only covers the side edge 310e of the optical film 310 for splicing. Using the light absorbing layer 250E to cover the side edge 310e of the optical film 310 produced by cutting can significantly reduce the visibility of the burrs in the dark state, which helps to improve the splicing display quality of the display device.

[0070] On the other hand, in this embodiment, the adhesive layer 130B may be doped with a plurality of light-absorbing particles 135. These light-absorbing particles 135 are suitable for absorbing ambient light from the outside. The material of the light-absorbing particles 135 may include carbon black or a masterbatch pigment / dye. By doping the adhesive layer 130B with these light-absorbing particles 135, the design flexibility of the optical film 310 can be increased. Since the other components and relative configuration relationships of this embodiment are similar to Figure 2 For detailed description of the display device 10, please refer to the relevant paragraphs of the aforementioned embodiment, which will not be repeated here.

[0071] Figure 9 FIG is a cross-sectional view of a display panel and a light absorbing layer according to a seventh embodiment of the present invention. Figure 9 , different from Figure 2In this embodiment, the display panel DP-F for the spliced ​​display device, the first light-emitting element LED1", the second light-emitting element LED2" and the third light-emitting element LED3" constituting the pixel unit PU-A can be directly bonded to the bonding pad (not shown) of the circuit board 100 (chip on board, COB) and encapsulated by a packaging glue layer.

[0072] Since the other components and their relative configuration relationships of this embodiment are similar to Figure 2 For detailed description of the display device 10, please refer to the relevant paragraphs of the aforementioned embodiment, which will not be repeated here.

[0073] Figure 10 is a schematic cross-sectional view of a display panel and a light absorbing layer according to an eighth embodiment of the present invention. Figure 11 FIG is a cross-sectional view of a display panel and a light absorbing layer according to a ninth embodiment of the present invention. Figure 10 The display panel DP-G of this embodiment is Figure 7 The difference between the display panels DP-D is that the light absorbing layer 250G of this embodiment can be divided into a first portion 250p1 and a second portion 250p2 that are separated from each other, wherein the first portion 250p1 covers the side edge 310e of the optical film 310 and part of the side edge 320e of the optical film 320, and the second portion 250p2 covers the side edge 260e of the second encapsulation layer 260.

[0074] That is to say, the light absorbing layer 250G of this embodiment is not as Figure 6 The light absorbing layer 250C is not integrally extended from the side edge 310e of the optical film 310 to cover the side edge 260e of the second encapsulation layer 260, but is respectively covered in two sections, namely, the side edge 310e of the optical film 310 (or the side edge 320e of the optical film 320) and the side edge 260e of the second encapsulation layer 260.

[0075] However, the present invention is not limited thereto. Figure 11 In another embodiment, the first portion 250p1′ of the light absorbing layer 250H of the display panel DP-H also covers the side edge 310e of the optical film 310 and part of the side edge 320e of the optical film 320, but the second portion 250p2″ covers the side edge 100e of the circuit board 100. In other words, under the premise that the first portion of the light absorbing layer covers the side edge of the optical film, the second portion can be separated from the first portion and cover the side edges of other film layers.

[0076] In summary, in a display device according to one embodiment of the present invention, a light-absorbing layer is provided at the joint of two display panels. By covering the side edge of the optical film of one display panel at the joint, this light-absorbing layer can significantly reduce the visibility of the joint in the dark state, thereby improving the display quality of the joint.

Claims

1. A display device comprising: The first display panel and the second display panel each have a circuit board, a plurality of light-emitting elements, a plurality of circuit substrates, an adhesive layer, and an optical film. The light-emitting elements are disposed between the circuit board and the optical film and are electrically connected to the circuit board. The first display panel and the second display panel have a joint. a light absorbing layer covering the side edge of the optical film at the joint of one of the first display panel and the second display panel, The circuit substrates are disposed between the light-emitting elements and the circuit board. The light-emitting elements are disposed on the circuit substrates and electrically connected to the circuit board via the circuit substrates. A first encapsulation layer is disposed on each of the circuit substrates. The adhesive layer connects the first encapsulation layer and the optical film. The light-absorbing layer extends to the side edge of the adhesive layer at the joint of one of the first display panel and the second display panel and covers at least a portion of the side edge of the adhesive layer.

2. The display device according to claim 1, wherein each of the circuit substrates is further provided with a pixel unit composed of a portion of the light-emitting elements to form a packaging structure, the first packaging layer covers the pixel unit, and the light transmittance of the first packaging layer is greater than 50%. 3 . The display device as claimed in claim 2 , wherein the first display panel and the second display panel each further comprise a second encapsulation adhesive layer, and the second encapsulation adhesive layer is disposed between the plurality of encapsulation structures and the optical film. The display device as claimed in claim 3 , wherein the light transmittance of the second encapsulation adhesive layer is greater than 10%.

5. The display device as claimed in claim 3, wherein the first encapsulation layer, the second encapsulation layer, and the circuit board respectively have a first surface, a second surface, and a third surface facing the optical film, and a distance between the second surface of the second encapsulation layer and the third surface of the circuit board is greater than or equal to a distance between the first surface of the first encapsulation layer and the third surface of the circuit board. 6 . The display device as claimed in claim 3 , wherein the light absorbing layer extends to a side edge of the second encapsulating adhesive layer of one of the first display panel and the second display panel at the joint, and covers at least a portion of the side edge of the second encapsulating adhesive layer. 7 . The display device as claimed in claim 1 , wherein the optical film is an anti-glare film, an anti-reflection film, a circular polarizer, a quarter-wave plate or a microstructure film. 8 . The display device as claimed in claim 1 , wherein the light absorption layer has a thickness along a direction perpendicular to the side edge of the optical film, and the thickness is in a range of 1 μm to 50 μm. 9 . The display device as claimed in claim 8 , wherein the thickness is in a range from 10 μm to 30 μm. 10 . The display device as claimed in claim 1 , wherein an optical density of the light absorbing layer is in a range of 0.7 to 2.5.

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