Patent Publication Number: US-2023165068-A1

Title: Display panel and display device

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application claims the priority of China Patent Application No. 201911372962.9, filed with the National Intellectual Property Administration on Dec. 27, 2019, titled “DISPLAY PANEL AND DISPLAY DEVICE”, which is incorporated by reference in the present application in its entirety. 
     FIELD OF DISCLOSURE 
     The present application relates to a field of display technology and in particular, to a display panel and a display device. 
     DESCRIPTION OF RELATED ART 
     In order to meet a growing demand for higher screen ratios, organic light-emitting diode (OLED) display panels with an under-screen camera have become one of the mainstream designs in the field of OLED display panels. Normally, a display panel with an under-screen camera is provided with a light transmissive region in a display region, and a through hole is formed by cutting off a corresponding portion in the light transmissive region to expose a camera assembly at the back of the OLED display panel, thereby forming the under-screen camera. When cutting out the through hole, a thin film encapsulation layer includes a CVD inorganic layer, and internal or external forces during cutting easily cause cracks at cutting edges, and the generated cracks can extend to the inside of the OLED display panel. 
     Therefore, a technical problem that needs to be solved at present is how to prevent the cracks, generated during the cutting of the through hole of the under-screen camera OLED display panel, from extending inwardly. 
     SUMMARY 
     The present application provides a display panel and a display device, which can solve a technical problem that cracks are generated and extended inwardly when an under-screen camera OLED display panel is cut to form a through hole. 
     Accordingly, the present application provides a technical solution as follows. The present application provides a display panel, comprising: 
     a display region, a light transmissive region, and a peripheral region, wherein the peripheral region surrounds the light transmissive region, and the display region surrounds the peripheral region; 
     an inorganic insulating layer, an organic insulating layer, and a thin film encapsulation layer which are stacked on a base substrate, wherein the thin film encapsulation layer comprises an inorganic layer and an organic layer stacked on each other; 
     wherein the organic insulating layer is disposed corresponding to the display region, the inorganic insulating layer and the thin film encapsulation layer are disposed corresponding to the display region, the peripheral region, and the light transmissive region, and a first through hole is defined in the display panel corresponding to the light transmissive region; 
     wherein at least one groove is defined in the inorganic insulating layer corresponding to the peripheral region, the organic layer is arranged at one side of the groove near the organic insulating layer, and a portion of the inorganic layer corresponding to the groove is in contact with the inorganic insulating layer at a side wall and a bottom of the groove. 
     In the display panel of the present application, in the peripheral region, a height difference is formed at the side wall of the groove and between a portion of the inorganic layer outside the groove and a portion of the inorganic layer corresponding to the bottom of the groove. 
     In the display panel of the present application, the at least one groove comprises a first groove formed in the light transmissive region and the peripheral region, and an orthographic projection of a bottom of the first groove projected on the display panel covers the light transmissive region. 
     In the display panel of the present application, the at least one groove further comprises a plurality of annular grooves formed in the peripheral region, and the annular grooves are located outside the first groove. 
     In the display panel of the present application, at least two annular grooves are arranged at intervals from a position close to the light transmissive region to a position away from the light transmissive region. 
     In the display panel of the present application, the inorganic insulating layer comprises a buffer layer, a gate insulating layer, and an interlayer insulating layer which are sequentially stacked, the organic insulating layer comprises a planarizing layer, a pixel definition layer, and a spacer layer which are stacked, and the at least one groove partially or entirely penetrates the inorganic insulating layer. 
     In the display panel of the present application, a rounded corner is formed between the side wall and the bottom of the groove, or an angle greater than or equal to 90° is formed between the side wall and the bottom of the groove. 
     In the display panel of the present application, the side wall of the groove is a flat surface, an arc surface, or a stepped structure. 
     The present application provides a display panel, comprising: 
     a display region, a light transmissive region, and a peripheral region, wherein the peripheral region surrounds the light transmissive region, and the display region surrounds the peripheral region; 
     an inorganic insulating layer, an organic insulating layer, and a thin film encapsulation layer which are stacked on a base substrate, wherein the thin film encapsulation layer comprises an inorganic layer and an organic layer stacked on each other; 
     wherein the organic insulating layer is disposed corresponding to the display region, the inorganic insulating layer and the thin film encapsulation layer are disposed corresponding to the display region, the peripheral region, and the light transmissive region, and a first through hole is defined in the display panel corresponding to the light transmissive region; 
     wherein at least one groove is defined in the inorganic insulating layer corresponding to the peripheral region, the organic layer is arranged at one side of the groove near the organic insulating layer, a portion of the inorganic layer corresponding to the groove is in contact with the inorganic insulating layer at a side wall and a bottom of the groove, and a boundary line of the groove is one or a combination of a straight line, an arc line, and a polyline. 
     In the display panel of the present application, in the peripheral region, a height difference is formed at the side wall of the groove and between a portion of the inorganic layer outside the groove and a portion of the inorganic layer corresponding to the bottom of the groove. 
     In the display panel of the present application, the at least one groove comprises a first groove arranged corresponding to the light transmissive region and the peripheral region, and an orthographic projection of the bottom of the first groove projected on the display panel covers the light transmissive region. 
     In the display panel of the present application, the at least one groove further comprises a plurality of annular grooves formed in the peripheral region, and the annular grooves are located outside the first groove. 
     In the display panel of the present application, at least two annular grooves are arranged at intervals from a position close to the light transmissive region to a position away from the light transmissive region. 
     In the display panel of the present application, the inorganic insulating layer comprises a buffer layer, a gate insulating layer, and an interlayer insulating layer which are sequentially stacked, the organic insulating layer comprises a planarizing layer, a pixel definition layer, and a spacer layer which are stacked, and the at least one groove partially or entirely penetrates the inorganic insulating layer. 
     In the display panel of the present application, a rounded corner is formed between the side wall and the bottom of the groove, or an angle greater than or equal to 90° is formed between the side wall and the bottom of the groove. 
     In the display panel of the present application, the side wall of the groove is a flat surface, an arc surface, or a stepped structure. 
     The present application provides a display device, comprising the display panel of claim  1  and a camera assembly, wherein the display panel comprises the display region, the light transmissive region, and the peripheral region, the peripheral region surrounds the light transmissive region, and the display region surrounds the peripheral region; 
     wherein a first through hole is defined in a portion of the display panel corresponding to the light transmissive region; 
     wherein the camera assembly is arranged on a back portion of the display panel and disposed corresponding to the first through hole, and the camera assembly is configured to photograph an object at one side of the display panel away from the camera assembly. 
     Advantages of the present application: 
     The present application provides the display panel and the display device. By forming the groove in the peripheral region outside the light transmissive region, the inorganic layer has the height difference at the groove in the peripheral region. That is, a portion of the inorganic layer forms a slope. Because the density of the inorganic insulating layer is greater than the density of the inorganic layer, the inorganic insulating layer located at the slope of the groove can stop cracks from extending inwardly during cutting, and the groove can stop cracks from extending inwardly during cutting. In addition, by providing multiple annular grooves in the peripheral region, cracks can be further prevented from extending inwardly. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Hereinafter, a description in conjunction with the accompanying figures is provided to more clearly illustrate the embodiments of the present disclosure, which will ease the understanding of the technical solutions and other beneficial effects of the present application. 
         FIG.  1    is a schematic structural view illustrating a display panel according to one embodiment of the present application. 
         FIG.  2    is a cross-sectional view taken along section line G-G′ in  FIG.  1   . 
         FIG.  3    is another cross-sectional view taken along the section line G-G′ in  FIG.  1   . 
         FIG.  4    is still another cross-sectional view taken along the section line G-G′ in  FIG.  1   . 
         FIG.  5    is a top view of a peripheral region and a light transmissive region in  FIG.  4   . 
         FIG.  6    is a schematic cross-sectional view illustrating a display device according to one embodiment of the present application. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     The following descriptions are provided with reference to the accompanying drawings to illustrate specific embodiments of the present application. The directional terms mentioned in the present application, such as “upper”, “lower”, “front”, “rear”, “left”, “right”, “inside”, “outside”, and “lateral”, are merely illustrative based on the accompanying drawings. Therefore, the directional terms are provided for ease of understanding the present application, are not used to limit the present application. In the figures, structurally similar elements are denoted by the same reference numerals. 
     The present application is directed to solving a technical problem of a conventional organic light-emitting diode (OLED) display panel with an under-screen camera. The problem is that cracks are generated and extended inwardly when a through hole is cut out in a light-transmissive region. The present application can solve this defect. 
     Please refer to  FIG.  1    illustrating a display panel according to one embodiment of the present application. For a higher screen ratio, the display panel  10  in the present application is an organic light-emitting diode (OLED) display panel with an under-screen camera. The OLED display panel comprises a display region A, a light transmissive region B, and a peripheral region C. The peripheral region C surrounds the light transmissive region B, and the display region A surrounds the peripheral region C. A portion of the display panel  10  corresponding to the light transmissive region B is cut to form a first through hole exposing the under-screen camera. 
       FIG.  2    is a cross-sectional view taken along section line G-G′ in  FIG.  1   . The display panel  10  comprises a base substrate  101 , a multi-layered inorganic insulating layer  102  disposed on the base substrate  101 , a multi-layered organic insulating layer  103  disposed on the inorganic insulating layers  102 , a multi-layered metal layer (not illustrated) disposed between the inorganic insulating layer  102  and the organic insulating layer  103 , a semiconductor layer (not illustrated) disposed in the multi-layered inorganic insulating layer  102 , a pixel electrode layer (not illustrated) disposed in the multi-layered organic insulating layer  103 , and a thin film encapsulation layer  104  disposed on the organic insulating layers  103 . The multi-layered inorganic insulating layer  102  comprises, but is not limited to, a buffer layer, a gate insulating layer, and an interlayer insulating layer. The organic insulating layer  103  comprises, but is not limited to, a planarizing layer  103   a , a pixel definition layer  103   b , and a spacer layer  103   c , and an organic light-emitting layer  103   d.    
     The first through hole entirely or partially penetrates one or more of the base substrate  101 , the inorganic insulating layer  102 , the organic insulating layer  103 , and the thin film encapsulation layer  104 . 
     The thin film encapsulation layer  104  is in direct contact with the inorganic insulating layer  102  in the light transmissive region B and the peripheral region C surrounding the light transmissive region B. The thin film encapsulation layer  104  comprises at least three layers which include an inorganic layer  104   a , an organic layer  104   b , and the inorganic layer  104   a  stacked on each other. A groove is defined in the inorganic insulating layer  102  in the peripheral region C, and the inorganic layer  104   a  forms a continuous thin film along the groove in the peripheral region C and the light transmissive region B. 
     Specifically, as shown in  FIG.  2   , the display panel  10  is provided with a first groove  11  formed in the peripheral region C and the light transmissive region B, and the first groove  11  is formed in the inorganic insulating layer  102 , and the first groove  11  partially penetrates or entirely penetrates the inorganic insulating layer  102 . 
     The organic layer  104   b  is located outside the first groove  11 . That is, the organic layer  104   b  is disconnected outside the first groove  11 . The inorganic layer  104   a  forms a continuous thin film in the light transmissive region B and the peripheral region C. A portion of the inorganic layer  104   a  corresponding to the first groove  11  is in close contact with the inorganic insulating layer  102  at a side wall  11   a  and a bottom  11   b  of the first groove  11 . An orthographic projection of the bottom  11   b  of the first groove  11  projected on the base substrate  101  covers the light transmissive region B. In the peripheral region C, a height difference is formed at the side wall  11   a  of the first groove  11  and between a portion of the inorganic layer  104   a  outside the first groove  11  and a portion of the inorganic layer  104   a  corresponding to the bottom  11   b  of the groove  11 . That is to say, in the peripheral region C, the inorganic layer  104   a  forms a climbing slope at the side wall  11   a  of the first groove  11  from one side close to the light transmissive region B toward one side away from the light transmissive region B. Moreover, process temperatures of the inorganic insulating layer  102  are about 370°, and the inorganic layer  104   a  is produced in a low-temperature process with process temperatures about 100°, so density of the inorganic insulating layer  102  is greater than density of the inorganic layer  104   a . Therefore, in cutting of a portion of the display panel corresponding to the light transmissive region B, cracks generated at cutting positions of the inorganic layer  104   a  stop at the slope, so the first groove  11  can stop the cracks from extending inwardly. 
     In the present embodiment, the first groove  11  is a circular groove, and the light transmissive region B is also of a circular shape. A diameter of the circular groove is 10 um to 100 um larger than a diameter of the light transmissive region B. In alternative embodiments, the light transmissive region B can have other shapes such as a rectangular shape or a U shape. Also, the shape of the first groove  11  is not limited to the above-mentioned shape, and the shape of the first groove  11  can be, for example, rectangular or polygonal, as long as the inorganic layer  104   a  can form a slope (a height difference) in the peripheral region C around the light transmissive region B. 
     According to one embodiment of the present invention, a boundary line of the first groove  11  is one or a combination of a straight line, an arc line, and a polyline. 
     In the present embodiment, an included angle between the side wall  11   a  and the bottom  11   b  of the first groove  11  is greater than or equal to 90°, so that the inorganic layer  104   a  can cover an entire surface of the first groove  11 . Therefore, continuous film formation of the inorganic layer  104   a  can be ensured. In alternative embodiment, a rounded corner is formed between the sidewall  11   a  and the bottom  11   b  of the first groove  11 , so that the inorganic layer  104   a  forms a continuous film at the corner between the sidewall  11   a  and the bottom  11   b  of the first groove  11 . Accordingly, the encapsulation effect of the thin film encapsulation layer  104  is ensured. 
     In the present embodiment, the side wall  11   a  of the first groove  11  can be a flat surface, an arc surface, or a stepped structure. If the side wall  11   a  is designed as a stepped structure, cracks have more paths to extend through from the bottom  11   b  to the outside of the first groove  11 , so that the cracks can be prevented from extending further inwardly in the display panel. 
     In another embodiment, a cross-sectional shape of the bottom  11   b  of the first groove  11  can also be a stepped structure, especially for a portion of the bottom  11   b  located in the peripheral region C. By using the stepped-structure design, cracks generated at a boundary of the light transmissive region B have more paths to extend through, thus preventing the cracks from extending further inwardly in the display panel. 
     As shown in  FIG.  3   , it is another cross-sectional view taken along the section line G-G′ in  FIG.  1   .  FIG.  3    is different from  FIG.  2    in that the display panel  10  of  FIG.  3    does not need to be provided with the first groove  11 , but instead forms at least one annular groove  12  in the peripheral region C. A diameter of the annular groove  12  is larger than a diameter of the light transmissive region B. The annular groove  12  is formed in the inorganic insulating layer  102 , and the annular groove  12  partially or entirely penetrates the inorganic insulating layer  102 . In the present embodiment, at least two annular grooves  12  are arranged at intervals from a position near the light transmissive region B to a position away from the light transmissive region B. In other words, multiple annular grooves  12  are formed in the peripheral region C. 
     The organic layer  104   b  is located outside the annular groove  12 , the inorganic layer  104   a  forms a continuous film in the light transmissive region B and the peripheral region C, and a portion of the inorganic layer  104   a  corresponding to the annular groove  12  is in close contact with the inorganic insulating layer  102  at the side wall  12   a  and the bottom  12   b  of the annular groove  12 . In the peripheral region C, a height difference is formed at the side wall  12   a  of the annular groove  12  and between a portion of the inorganic layer  104   a  outside the annular groove  12  and a portion of the inorganic layer  104   a  corresponding to the bottom  12   b  of the annular groove  12 . In other words, the inorganic layer  104   a  forms multiple slopes in the peripheral region C. Therefore, in cutting a portion of the display panel corresponding to the light transmissive region B, cracks generated at cutting positions of the inorganic layer  104   a  stop at the slopes, so the annular groove  12  can stop the cracks from extending further inwardly. 
     The at least two annular grooves  12  can have the same or different depths. In one embodiment, the depths of the annular grooves  12  gradually increase from one side near the light transmissive region B to one side away from the light transmissive region B, and thereby the annular grooves  12  can better avoid crack extension. 
     The side wall  12   a  and the bottom  12   b  of the annular groove  12  can have similar structures as those of the first groove  11 , so please refer to the above description of the first groove  11  for details about these structures. 
     Please refer to  FIG.  4   , which is still another cross-sectional view taken along the section line G-G′ in  FIG.  1   . Please also refer to  FIG.  5    together, which is a top view of the peripheral region and the light transmissive region in  FIG.  4   .  FIG.  4    is different from  FIG.  2    and  FIG.  3    in that, the display panel  10  in  FIG.  4    comprises both the first groove  11  and the annular groove  12 , and the annular groove  12  is located outside the first groove  11 . For more details about the structures of the first groove  11  and the annular groove  12 , please refer to the description in the above embodiments, and a detailed description thereof is omitted herein. Since the annular groove  12  is additionally arranged outside the first groove  11 , cracks can be prevented from extending inward to the maximum extent. 
     The present application also provides a display device. As shown in  FIGS.  1  and  6   , the display device comprises the display panel  10  and a camera assembly  20  as described above. The display panel  10  comprises the display region A, the light transmissive region B, and the peripheral region C. The peripheral region C surrounds the light transmissive region B, and the display region A surrounds the peripheral region C. By cutting, a first through hole  13  is formed penetrating through upper and lower surfaces of a portion of the display panel  10  corresponding to the light transmissive region B. The camera assembly  20  is arranged on a back portion of the display panel  10  corresponding to the first through hole  13 , and the camera assembly  20  is used to photograph an object at one side of the display panel  10  away from the camera assembly  20 . 
     For more details about the structure of the display panel  10 , please refer to the description in the above embodiment, and a detailed description thereof is repeated herein for brevity. 
     In summary, although the present application has been disclosed above with preferable embodiments, the above preferable embodiments are not intended to limit the present application. Those skilled in the art can make various modifications without departing from the spirit and scope of the present application. Therefore, the protection scope of the present application should be defined by the appended claims.