Patent Publication Number: US-2023165116-A1

Title: Display panel

Description:
FIELD OF INVENTION 
     The present disclosure relates to the field of display technologies, and more particularly, to a display panel. 
     BACKGROUND OF INVENTION 
     In the current market, narrow-border screens or border-less screens have become the main direction of small-sized mobile phones. Realizing a small-sized display panel with a narrow-border design to achieve a great screen-body ratio is a direction that the industry has been working hard. 
     A display panel includes generally a substrate, an array layer, a light-emitting device layer, an encapsulation layer, and a touch layer with a stacked arrangement. An upper border area of the display panel is generally provided with electronic components, such as a front camera. In order to reduce the upper border area, in this industry, the camera is disposed under the screen, and a light-transmitting hole is opened in the area placing the camera. That is, the light-shielding film layer in a camera area, such as the metal layer in the array layer, and the cathode layer in the light-emitting device layer, is removed to form the light-transmitting hole. However, when the light-transmitting hole is formed, cracks may be formed on the substrate near the edge of the light-transmitting hole. Generally, an optical adhesive layer is filled at the edge of the light-transmitting hole to prevent a touch layer from an uneven depth caused by the cracks formed on the substrate during the formation of the touch layer. 
     However, the optical adhesive layer has high light transmittance, and the area with the light-transmitting hole is prone to light leakage, thereby affecting the normal operation of organic light emitting diode (OLED) device. 
     Technical Problems 
     In the existing display panel, the adhesive layer is filled at the edge of the light-transmitting hole, and the optical adhesive layer has high light transmittance, thereby the area with the light-transmitting hole is prone to light leakage. 
     SUMMARY OF INVENTION 
     Technical Solutions 
     In a first aspect, the present disclosure provides a display panel, the display panel has a display area and an additional function area, the display area surrounds at least a portion of the additional function area, and the display panel includes: 
     a substrate; 
     an array layer disposed on the substrate; 
     a light-emitting device layer disposed on the array layer; 
     an encapsulation layer covering the light-emitting device layer; 
     a touch layer disposed on the encapsulation layer; 
     wherein an opening area surrounded by the additional function area is disposed at an edge position of the additional function area, an opening penetrating the array layer and extending to a surface of the substrate is disposed by the opening area, and the opening is filled with a light-blocking layer. 
     In some embodiments, the light-blocking layer is made of a black material. 
     In some embodiments, the black material comprises polyimide. 
     In some embodiments, an upper surface of the light-blocking layer is flush with an upper surface of a portion of the encapsulation layer located in the display area. 
     In some embodiments, a groove located in the opening area is defined by the substrate surrounding the additional function area. 
     In some embodiments, a width of a bottom portion of the groove is greater than a width of a top portion of the groove. 
     In some embodiments, a portion of the encapsulation layer is in the groove. 
     In some embodiments, a portion of the encapsulation layer in the opening area is covered by the light-blocking layer, and the groove is filled with the light-blocking layer. 
     In some embodiments, a plurality of grooves are provided and spaced from each other. 
     In some embodiments, a retaining wall located in the opening area is disposed on the substrate surrounding the additional function area. 
     In some embodiments, a plurality of grooves are defined respectively by an inner side of the retaining wall and an outer side of the retaining wall. 
     In a second aspect, the present disclosure further provides a display panel, the display panel has a display area and an additional function area, the display area surrounds at least a portion of the additional function area, and the display panel includes: 
     a substrate; 
     an array layer disposed on the substrate; 
     a light-emitting device layer disposed on the array layer; 
     an encapsulation layer covering the light-emitting device layer; and 
     a touch layer disposed on the encapsulation layer; 
     wherein an opening area surrounded by the additional function area is disposed at an edge position of the additional function area, an opening penetrating the array layer and extending to a surface of the substrate is defined by the opening area, and the opening is filled with a light-blocking layer, wherein the light-blocking layer is made of a black material, and an upper surface of the light-blocking layer is flush with an upper surface of a portion of the encapsulation layer located in the display area. 
     In some embodiments, the black material comprises polyimide. 
     In some embodiments, a groove located in the opening area is defined by the substrate surrounding the additional function area. 
     In some embodiments, a width of a bottom portion of the groove is greater than a width of a top portion of the groove. 
     In some embodiments, a portion of the encapsulation layer is in the groove. 
     In some embodiments, a portion of the encapsulation layer in the opening area is covered by the light-blocking layer, and the groove is filled with the light-blocking layer. 
     In some embodiments, a plurality of grooves are provided and spaced from each other. 
     In some embodiments, a retaining wall located in the opening area is disposed on the substrate surrounding the additional function area. 
     In some embodiments, a plurality of grooves are defined respectively by an inner side of the retaining wall and an outer side of the retaining wall. 
     Beneficial Effect: 
     The light-blocking layer is used to fill the cracks on the substrate and planarize the substrate to prevent the touch layer from an uneven depth caused by the cracks during the formation of the touch layer. In addition, the light-blocking layer is also used to prevent light leakage at the opening, thereby avoiding the light leakage affecting the performance of the OLED device. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG.  1    is a schematic diagram of a display panel according to one embodiment of the present disclosure. 
         FIG.  2    is a schematic structural diagram of a portion of a display panel according to one embodiment of the present disclosure. 
         FIG.  3    is a schematic structural diagram of a display panel according to one embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     In order to make the purpose, technical solutions, and effects of the present application clearer and clearer, the present application will be described in further detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application. 
     The present disclosure focus on the technical problems in the existing display panel that the adhesive layer is filled at the edge of the light-transmitting hole, and the optical adhesive layer has high light transmittance, thereby the area with the light-transmitting hole is prone to light leakage. 
     As shown in  FIG.  1    and  FIG.  2   , a display panel is provided. The display panel has a display area  81  and an additional function area  82 , the display area  81  surrounds at least a portion of the additional function area  82 . The display area  81  is used for displaying, and the additional function area  82  is used for correspondingly disposing optical devices such as cameras and optical sensors. A light-transmitting hole is defined by the additional function area  82 , and the light-transmitting hole is used to a light-transmitting channel for the optical devices. 
     Specifically, the display panel includes a substrate  10 , an array layer  20  disposed on the substrate  10 , a light-emitting device layer  30  disposed on the array layer  20 , an encapsulation layer  40  covering the light-emitting device layer  30 , and a touch layer  50  disposed on the encapsulation layer  40 . 
     In which, the light-transmitting hole may penetrate the substrate  10  and the array layer  20 . 
     In one embodiment, the substrate  10  includes a first basic layer  11 , a second basic layer  12 , and an isolation layer  13  between the first basic layer  11 . The material of the first basic layer  11  and the second basic layer  12  is light-transmitting polyimide. 
     Specifically, an opening area  83  surrounded by the additional function area  82  is disposed at an edge position of the additional function area  82 , and an opening  92  penetrating the array layer  20  and extending to a surface of the substrate  10  is defined by the opening area  83 . 
     It should be noted that the opening  92  that penetrates the array layer  20  and extends to the surface of the substrate  10  is formed by laser cutting or the like, after the array layer  20  is formed on the substrate  10 . 
     Specifically, the opening  92  is filled with a light-blocking layer  93 . 
     After the encapsulation layer  40  is formed on the light-emitting device layer  30 , the opening  92  is filled with a light-blocking material to form the light-blocking layer  93 . It should be noted that when the opening  92  is formed by cutting, cracks are easily formed on a portion of the substrate  10  located at the edge of the additional function area  82 . The light-blocking layer  93  is used to fill the cracks on the substrate  10  and planarize the substrate  10  to prevent the touch layer  50  from an uneven depth caused by the cracks during the formation of the touch layer  50 . In addition, the light-blocking layer  93  is also used to prevent light leakage at the opening  92 , thereby avoiding the light leakage affecting the performance of the OLED device. 
     Specifically, the light-blocking layer  93  is made of a black material. The black material has a strong absorption ability, therefore the light-blocking layer  93  has a high light-blocking ability. 
     In one embodiment, the material of the light-blocking layer  93  includes black polyimide. 
     It should be noted that the material of the substrate  10  includes polyimide. The light-blocking layer  93  is formed with the same material as substrate  10 , so that the light-blocking layer  93  can better fill the cracks  14  on substrate  10 , preventing water and oxygen from invading from the side surface of substrate  10 . 
     It should be noted that, in actual implementation, the material of the light-blocking layer  93  may also be black silicon nitride or silicon oxide, etc. 
     Specifically, a retaining wall  94  located in the opening area  83  is disposed on the substrate  10  surrounding the additional function area  82 . 
     The retaining wall  94  is used to prevent the organic material in the array layer  20  from flowing into the additional function area  82 , thereby preventing the organic material from affecting the light-capturing of photosensitive elements such as the camera. In addition, the retaining wall  94  also can prevent water and oxygen from invading from the side portion along with the organic material in array layer  20 . 
     In one embodiment, a gap is defined between the retaining wall  94  and an inner sidewall of the opening  92 . 
     It is known to the person skilled in the art that when the opening  92  is formed by cutting, cracks  14  are easily formed on the substrate  10  at the edge position of the opening  92 , and the cracks  14  is denser in a region where close to the inner wall of the opening  92 . By defining the gap between the retaining wall  94  and the inner sidewall of the opening  92 , the area with the dense cracks  14  is covered by a second inorganic layer  43 , thereby preventing water and oxygen from invading the OLED device through the cracks  14 . Specifically, the light-blocking layer  93  covers the retaining wall  94  and fills the gap. 
     In one embodiment, the retaining wall is covered by the encapsulation layer  40 , wherein the encapsulation layer  40  includes a first inorganic layer  41 , organic layer  42 , and the second inorganic layer  23  with a stacked arrangement. 
     It should be noted that, for the person skilled in the art, the organic material layer has a better flatness, and it is easy to form a flat film layer on the organic material layer. The inorganic material layer has a desirable water and oxygen barrier ability, which can prevent the water and oxygen from invading the display device. 
     Specifically, an upper surface of the light-blocking layer  93  is flush with an upper surface of a portion of the encapsulation layer  40  located in the display area  91 . 
     Further, the upper surface of the light-blocking layer  93  is flush with an upper surface of a portion of the second inorganic layer  43  located in the display area  91 , such that the touch layer  50  can be formed uniformly. 
     Specifically, a groove  14  located in the opening area  83  is defined by the substrate  10  surrounding the additional function area  82 . 
     When the organic layer  42  is formed, the groove  14  is used to prevent the organic layer  42  from extending toward the additional function area  82 , thereby preventing water and oxygen from invading the OLED device from the side surface. 
     Further, a width of a bottom portion of the groove  14  is greater than a width of a top portion of the groove  14 , such that a better partition effect is obtained. 
     Specifically, a portion of the encapsulation layer  14  is in the groove  14 . 
     The portion of the encapsulation layer  14  is used to fill a portion of the groove  14  to prevent water and oxygen from invading from the side portion of the groove  14 . 
     Further, a portion of the encapsulation layer  40  in the opening area  83  is covered by the light-blocking layer  93 , and the groove  14  is filled with the light-blocking layer  93 . 
     The encapsulation layer  40  is used to prevent water and oxygen from invading from the side, and to fill the groove  14  to prevent the touch layer from form an uneven depth caused during the formation of the touch layer. 
     Further, a plurality of grooves  14  are provided and spaced from each other. 
     Further, the plurality of grooves  14  are defined respectively by an inner side of the retaining wall  94  and an outer side of the retaining wall  94 . 
     It should be noted that  FIG.  2    only illustrates the case where one groove  14  is defined by the outer side the retaining wall  94 . In actual implementation, a plurality of grooves  14  may also be defined by the outer side of the retaining wall  94 . 
     In one embodiment, as shown in  FIG.  3   , the array layer  20  includes an active layer  21  disposed on the substrate  10 , a first gate insulating layer  22  covering the active layer  21 , a first gate electrode layer  23  disposed on the first gate insulating layer  22 , a second gate insulating layer  24  covering the first gate electrode layer  23 , a second gate electrode layer  25  disposed on the second gate insulating layer  24 , a interlayer dielectric layer  26  covering the second gate electrode layer  25 , a source/drain  27  disposed on the interlayer dielectric layer  26 , a planarization layer  28  covering the source/drain  27 , and a pixel definition layer  29  disposed on the planarization layer  28 . 
     Specifically, the light-emitting device layer  30  includes an anode metal layer  31  disposed on the planarization layer  28 , a light-emitting layer  32  disposed on the anode metal layer  31 , and a cathode metal layer  33  disposed on the pixel definition layer  29  and covering the light-emitting layer  32 , wherein the encapsulation layer  40  is disposed on the cathode metal layer  33 . 
     Specifically, the display panel further includes a polarizer  60  disposed on the touch layer  50 , and a package cover plate  70  disposed on the polarizer  60 . 
     The beneficial effects of the present disclosure are: the light-blocking layer  93  is used to fill the cracks  14  and the opening area  83  on the substrate  10 , and planarize the substrate  10  to prevent the touch layer  50  from an uneven depth caused by the cracks  14  during the formation of the touch layer  50 . In addition, the light-blocking layer  93  is also used to prevent light leakage at the opening  92 , thereby avoiding the light leakage affecting the normal operation of the optical elements such as cameras. 
     In view of the above, although the present invention has been disclosed by way of preferred embodiments, the above preferred embodiments are not intended to limit the present invention, and one of ordinary skill in the art, without departing from the spirit and scope of the invention, the scope of protection of the present invention is defined by the scope of the claims.