Patent Publication Number: US-2022216448-A1

Title: Display device

Description:
FIELD OF INVENTION 
     The present disclosure relates to the technical field of display, and particularly to a display device. 
     BACKGROUND 
     Currently, a surface of a foldable product is covered with a reinforced ultra-thin glass (UTG). However, due to characteristics of the reinforced ultra-thin glass itself, edges of the reinforced ultra-thin glass are susceptible to impacts, causing cracks and breakage. 
     Accordingly, it is necessary to provide a new display device to cushion and protect edges of foldable products. 
     SUMMARY OF DISCLOSURE 
     The present disclosure provides a display device, wherein a glass layer is disposed between a first adhesive layer and a second adhesive layer, the glass layer is made of reinforced ultra-thin glass, peripheral edges of the glass layer are indented with respect to peripheral edges of the first adhesive layer and the second adhesive layer to form an indented region, and a buffer layer is disposed in the indented region. The buffer layer can prevent adhesion between the first adhesive layer and the second adhesive layer, and protect the edges of the glass layer, thereby preventing cracks, breakage, and other problems, and increasing buffer effect. 
     In a first aspect, the present disclosure provides a display device comprising: a cover plate; a first adhesive layer disposed on a side of the cover plate; a glass layer disposed on the first adhesive layer and made of reinforced ultra-thin glass; a second adhesive layer disposed on the glass layer, wherein peripheral edges of the glass layer are indented with respect to peripheral edges of the first adhesive layer and the second adhesive layer to form an indented region; and a buffer layer disposed in the indented region. 
     In the display device, the buffer layer is made of a polymer glue. 
     In the display device, the first adhesive layer and the second adhesive layer are made of an optically clear adhesive. 
     The display device has a main display area and an edge area and further comprises a light shielding layer disposed on a side of the cover plate close to the first adhesive layer in the edge area. 
     In the display device, an orthographic projection of the light shielding layer on the cover plate covers an orthographic projection of the indented region on the cover plate. 
     The display device further comprises a display module. The display module comprises a function control layer disposed on a side of the glass layer away from the cover plate, and a display layer disposed on a side of the function control layer away from the glass layer. 
     In the display device, the display layer is a flexible organic light-emitting diode (OLED) display panel, and the function control layer is a touch layer or a polarizer. 
     The display device further comprises a back plate layer disposed on a side of the display module away from the cover plate. 
     In a second aspect, the present disclosure provides a display device comprising: a cover plate; a first adhesive layer disposed on a side of the cover plate; a glass layer disposed on the first adhesive layer; a second adhesive layer disposed on the glass layer, wherein one or more edges of the glass layer are indented with respect to corresponding edges of the first adhesive layer and the second adhesive layer to form an indented region; and a buffer layer disposed in the indented region. 
     In the display device, the glass layer is made of reinforced ultra-thin glass. 
     In the display device, circumference of the glass layer is indented with respect to circumference of the first adhesive layer and the second adhesive layer by a distance greater than or equal to 0.25 mm. 
     In the display device, the buffer layer is made of a polymer glue. 
     In the display device, the first adhesive layer and the second adhesive layer are made of an optically clear adhesive. 
     The display device has a main display area and an edge area and further comprises a light shielding layer disposed on a side of the cover plate close to the first adhesive layer in the edge area. 
     In the display device, an orthographic projection of the light shielding layer on the cover plate covers an orthographic projection of the indented region on the cover plate. 
     The display device further comprises a display module. The display module comprises a function control layer disposed on a side of the glass layer away from the cover plate, and a display layer disposed on a side of the function control layer away from the glass layer. 
     In the display device, the display layer is a flexible organic light-emitting diode (OLED) display panel, and the function control layer is a touch layer or a polarizer. 
     The display device further comprises a back plate layer disposed on a side of the display module away from the cover plate. 
     In a display device provided by the present disclosure, a glass layer is disposed between a first adhesive layer and a second adhesive layer, the glass layer is made of reinforced ultra-thin glass, peripheral edges of the glass layer are indented with respect to peripheral edges of the first adhesive layer and the second adhesive layer to form an indented region, and a buffer layer is disposed in the indented region. Compared with the prior art, the buffer layer can prevent adhesion between the first adhesive layer and the second adhesive layer, and protect the edges of the glass layer, thereby preventing cracks, breakage, and other problems, and increasing buffer effect. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic structural diagram of a display device according to an embodiment of the present disclosure. 
         FIG. 2  is a schematic longitudinal cross-sectional view of a display device according to another embodiment of the present disclosure. 
       Element numerals are described as follows:  100 ,  110 : cover plate;  200 ,  210 : first adhesive layer;  300 ,  310 : glass layer;  400 ,  410 : second adhesive layer;  500 ,  510 : display module;  501 ,  511 : function control layer;  502 ,  512 : display layer;  1 ,  2 : indented region;  10 ,  11 : main display area;  20 ,  21 : edge area;  600 , 610 : buffer layer;  700 , 710 : light shielding layer; and  800 ,  810 : back plate layer. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure provides a display device. In order to make purposes, technical solutions, and effects of the present invention clearer and more definite, the present invention will be further described in detail below with reference to accompanying drawings and embodiments. It should be understood that specific embodiments described herein are only used to explain the present invention, not used to limit the present invention. 
     Please refer to  FIG. 1 , which is a schematic structural diagram of a display device according to an embodiment of the present disclosure. The present disclosure provides a display device having characteristics such as good foldability and bendability. As shown in  FIG. 1 , the display device comprises a cover plate  100 , a first adhesive layer  200 , a glass layer  300 , a second adhesive layer  400 , and a display module  500 . The glass layer  300  is disposed on a side of the cover plate  100 . The display module  500  is disposed on a side of the glass layer  300  away from the cover plate  100 . The first adhesive layer  200  is configured to fix the glass layer  300  to the cover plate  100 . The second adhesive layer  400  is configured to fix the glass layer  300  to the display module  500 . As shown in  FIG. 1 , one or more edges of the glass layer  300  are indented with respect to corresponding edges of the first adhesive layer  200  and the second adhesive layer  400  to form one or more indented regions  1 . 
     Preferably, peripheral edges of the glass layer  300  are indented with respect to the corresponding edges of the display module  500  by a distance greater than or equal to 0.25 mm to form the indented regions  1 . The glass layer  300  is configured to improve impact resistance of the entire display device. 
     More specifically,  FIG. 1  is only used as a preferred embodiment.  FIG. 1  is only a cross-sectional view of one of edges, which shows that the indented region  1  is formed only at a right edge of the glass layer  300 . In other embodiments, the indented region  1  may be formed only at a left edge of the glass layer  300 . The indented regions  1  may also be formed only at opposite sides (the right edge and the left edge) of the glass layer  300 . Alternatively, preferably, the indented regions  1  are formed at all edges around the glass layer  300 . The present disclosure does not limit a/an specific location, number, indented distance, or indented area of the indented regions  1 . These parameters can be changed according to an actual model structure of the display device, and main purpose is to improve impact resistance of the display module  500 . 
     In a preferred embodiment of the present disclosure, as shown in  FIG. 1 , the glass layer  300  is made of reinforced ultra-thin glass (UTG). 
     In this preferred embodiment, the reinforced ultra-thin glass has good foldability, good flexibility, smooth hand feel, good uniformity, high strength, high hardness, and good optical properties of glass. Therefore, the display module  500  provided with the reinforced ultra-thin glass has good impact resistance. When the glass layer  300  is broken by an impact, its fragments can be prevented from scattering, which is safer. The reinforced ultra-thin glass is suitable for foldable display devices. The display device may be a foldable mobile phone, a tablet computer, an electronic reader, an electronic photo album, an exhibition window, or the like. 
     In a manufacturing process of the reinforced ultra-thin glass, a common glass usually needs to be thinned by computer numeric control (CNC) edging or subsequent grinding and polishing processes to form ultra-thin glass, surfaces of the ultra-thin glass are chemically reinforced by ion exchange to obtain the reinforced ultra-thin glass, and strength of the reinforced ultra-thin glass is enhanced by laser processing. 
     In an embodiment of the present disclosure, the first adhesive layer  200  and the second adhesive layer  400  are preferably made of an optically clear adhesive (OCA). In other embodiments, the first adhesive layer  200  may be made of an optically clear adhesive tape, liquid optically clear adhesive (LOCA), optically clear resin (OCR), polyvinyl butyral, or ethylene-vinyl acetate copolymer. The second adhesive layer  400  may be made of an optically clear adhesive tape, liquid optically clear adhesive, optically clear resin, polyvinyl butyral, or ethylene-vinyl acetate copolymer. In some embodiments, the first adhesive layer  200  and the second adhesive layer  400  are both double-faced adhesive tape. The first adhesive layer  200  and the second adhesive layer  400  are configured to bond the cover plate  100  and the display module  500  to the glass layer  300 , respectively, and realize double-sided support, which is beneficial to improve a sealing degree between the display module  500 , the cover plate  100 , and the glass layer  300 . 
     As shown in  FIG. 1 , a buffer layer  600  is disposed in each of the indented regions  1 . In  FIG. 1 , the buffer layer  600  overlaps with the corresponding indented region  1 , and the buffer layer  600  is not shown with cross-section lines to ensure that the corresponding indented region  1  is clearly shown. 
     In this embodiment, the buffer layers  600  are disposed between the first adhesive layer  200  and the second adhesive layer  400 . That is, the buffer layers  600  are disposed on a same layer as the glass layer  300 , and are in contact with corresponding edges of the glass layer  300 . The buffer layers  600  are supported and fixed between the first adhesive layer  200  and the second adhesive layer  400 . This prevents the first adhesive layer  200  and the second adhesive layer  400  from adhering to each other in a natural state where the indented regions  1  are not filled. The buffer layers  600  are configured to indirectly protect the edges of the glass layer  300 , thereby increasing buffer effect. The buffer layers  600  are made of a polymer glue. Preferably, the buffer layers  600  are made of room temperature vulcanized silicone rubber, silicone glue, polyurethane glue, polyvinyl butyral, or ethylene-vinyl acetate copolymer. 
       FIG. 1  mainly shows a structure of an edge of the display device, and an overall structure of the display device is not limited by  FIG. 1 . For example, in an embodiment, the cover plate  100  is preferably a three-dimensional (3D) cover plate or another flexible cover plate. When the cover plate  100  is a  3 D cover plate, a surface of the cover plate  100  facing the display module  500  is concave, the cover plate  100  is configured to accommodate the display module  500 , and the cover plate  100  and the display module  500  are attached to each other to form the display device. In other embodiments, the cover plate  100  may also have a planar structure. 
     Continue to see  FIG. 1 . In this embodiment, the display device has a main display area  10  and one or more edge areas  20 . A light shielding layer  700  is disposed on a side of the cover plate  100  close to the first adhesive layer  200 . The light shielding layer  700  is made of an opaque material. The light shielding layer  700  is configured to shield light. The light shielding layer  700  is disposed in the edge areas  20 . As shown in  FIG. 1 , an orthographic projection of the light shielding layer  700  on the cover plate  100  covers an orthographic projection of each of the indented regions  1  on the cover plate  100 . 
     Continue to see  FIG. 1 . The display module  500  is flexible and comprises a plurality of functional layers that are stacked. As shown in  FIG. 1 , the display module  500  comprises a function control layer  501  and a display layer  502  that are stacked. The function control layer  501  is disposed on a side of the glass layer  300  away from the cover plate  100 . The display layer  502  is disposed on a side of the function control layer  501  away from the glass layer  300 . More specifically, in this embodiment, the display module  500  is disposed on a side of the second adhesive layer  400  away from the glass layer  300 . At this time, the function control layer  501  is disposed on the side of the second adhesive layer  400  away from the glass layer  300 , and the display layer  502  is disposed on a side of the function control layer  501  away from the second adhesive layer  400 . 
     It should be noted that, in this embodiment, the display layer  502  is a flexible organic light-emitting diode (OLED) display panel and comprises a thin film transistor array substrate. As a preferred embodiment, the function control layer  501  is a touch layer or a polarizer. 
     In other embodiments, the function control layer  501  may be, but is not limited to, a touch layer or a polarizer. The function control layer  501  may also be another functional layer to make performance of the display module  500  better. In an embodiment of the present disclosure, when the function control layer  501  is a touch layer, the touch layer may have an on-cell structure. The touch layer is disposed on the thin film transistor array substrate, and the touch control layer is connected to the thin film transistor array substrate. The thin film transistor array substrate sequentially comprises a thin film transistor array layer, an OLED light emitting layer, and a thin-film encapsulation layer. The OLED light emitting layer comprises an anode electrode, a hole injection layer, a hole transport layer, an organic light emitting layer, an electron transport layer, an electron injection layer, and a cathode electrode which are sequentially formed on the thin film transistor array substrate. The thin-film encapsulation layer covers the OLED light emitting layer. 
     In addition, in other embodiments, the touch layer may also have an in-cell structure. That is, the touch layer is changed to be built into the thin film transistor array substrate of the display layer  502 . 
     In this embodiment, the display layer  502  is equivalent to a flexible imaging device and is configured for image display. The touch layer is configured to collect sensing signals and to implement a touch function. The touch layer may also be a flexible thin-film capacitive touch panel. 
     In a preferred embodiment, the display layer  502  is an OLED display panel, and the function control layer  501  is a polarizer. Because OLED is self-luminous, theoretically OLED may not require a polarizer required for liquid crystal display (LCD). However, external light will be reflected by the cathode electrode, which will affect a viewing effect and contrast. In order to solve the above problem, a polarizer +a ¼λwave plate (i.e., circular polarizing filter) is used. When the external light passes through the polarizer first, a half of the external light cannot pass through. This half of the external light is deviated by  90  degrees from the original external light after being reflected by the ¼λ wave plate. The reflected light cannot pass through the polarizer, which solves the above problem. Therefore, when the function control layer  501  is a polarizer, it has an effect of preventing the external light from being reflected by the cathode electrode. 
     As shown in  FIG. 1 , the display device further comprises a back plate layer  800  disposed on a side of the display module  500  away from the cover plate  100 . More specifically, the back plate layer  800  is disposed on a side of the display layer  502  away from the cover plate  100 . In this embodiment, the back plate layer  800  supports the display module  500 . 
     Please refer to  FIG. 2 . In a preferred embodiment of the present disclosure, a display device comprises a cover plate  110 , a first adhesive layer  210 , a glass layer  310 , a second adhesive layer  410 , a display module  510 , and a back plate layer  810  stacked sequentially. The display module  510  comprises a function control layer  511  and a display layer  512  that are stacked. The function control layer  511  is disposed on a side of the glass layer  310  away from the cover plate  110 . The display layer  512  is disposed on a side of the function control layer  511  away from the glass layer  310 . 
     It should be particularly noted that, in this preferred embodiment, peripheral edges of the glass layer  310  are all indented with respect to peripheral edges of the display module  510  to form an indented region  2 . It can be understood from  FIG. 2  that  FIG. 2  only schematically shows that opposite edges of the glass layer  310  are indented with respect to the corresponding edges of the display module  510  to form the indented regions  2 . Although  FIG. 2  only shows that the glass layers  310  are formed at a right edge and a left edge of the glass layer  310 , in fact, in this preferred embodiment, the peripheral edges of the glass layer  310  are all actually indented with respect to the peripheral edges of the display module  510  to form the indented region  2 . 
     In other embodiments, the indented region  2  may be replaced by only indented regions formed at the opposite edges (the right edge and the left edge) of the glass layer. That is, the opposite edges of the glass layer are indented with respect to corresponding opposite edges of the display module (or the first adhesive layer and the second adhesive layer of the display device) to form the indented regions. That is, the indented regions are respectively formed on the opposite sides of the glass layer. 
     In the display device as shown in  FIG. 2 , a/an specific location, number, indented distance, or indented area of the indented region  2  are not limited. These parameters can be changed according to an actual model structure of the display device, and main purpose is to improve impact resistance of the display module  510 . 
     Furthermore, the display device has a main display area  11  and one or more edge areas  21 . A light shielding layer  710  is disposed on a side of the cover plate  110  close to the first adhesive layer  210 . The light shielding layer  710  is disposed in the edge areas  21 . As shown in  FIG. 2 , an orthographic projection of the light shielding layer  710  on the cover plate  110  covers an orthographic projection of the indented region  2  on the cover plate  110 . 
     Moreover, a buffer layer  610  is disposed in the indented region  2 . In this embodiment, the buffer layer  610  is disposed between the first adhesive layer  210  and the second adhesive layer  410 . That is, the buffer layer  610  is disposed on a same layer as the glass layer  310 , and is in contact with corresponding edges of the glass layer  310 . The buffer layer  610  is supported and fixed between the first adhesive layer  210  and the second adhesive layer  410 . This prevents the first adhesive layer  210  and the second adhesive layer  410  from adhering to each other in a natural state where the indented region  2  is not filled. The buffer layer  610  is configured to indirectly protect the edges of the glass layer  310 , thereby increasing buffer effect. 
     In the display device provided by the present disclosure, the one or more edges of the glass layer are indented with respect to the corresponding edges of the first adhesive layer and the second adhesive layer to form the one or more indented regions. Specifically, the peripheral edges of the glass layer may be indented with respect to the peripheral edges of the first adhesive layer and the second adhesive layer to form the indented regions. The opposite edges of the glass layer may be indented with respect to the corresponding opposite edges of the first adhesive layer and the second adhesive layer to form the indented regions. A buffer layer is disposed in each of the indented regions. The glass layer is made of reinforced ultra-thin glass. The buffer layers can prevent adhesion between the first adhesive layer and the second adhesive layer, and protect the edges of the glass layer, thereby preventing cracks, breakage, and other problems, and increasing buffer effect. 
     For specific implementation of each of the aforementioned operations, please refer to the previous embodiment, which will not be described in detail herein. 
     It should be understood that those skilled in the art may make equivalent replacements or changes based on the technical solutions and inventive concepts of the present application, and all such changes or replacements shall fall within the scope of the claims of the present application.