Patent Publication Number: US-2020287160-A1

Title: Display panel and display device

Description:
FIELD OF INVENTION 
     The present invention relates to a field of display, and, more particularly, to a display panel and a display device. 
     BACKGROUND OF INVENTION 
     To increase the screen-to-body ratio of an electric product, a non-display region on a display panel is compressed smaller and smaller. For instance, in a display panel of a mobile phone or a handheld terminal, functional devices of the handheld terminal, such as a front camera and an earphone, are disposed in a predetermined notch defined in a top side of a display region in order to compress the non-display region as much as possible. 
       FIG. 1  is a top plan view of a conventional display panel. As shown in  FIG. 1 , a frame  10  with a flat panel shape covers a display region  11 , wherein the frame  10  is a non-display region. A notch  12  is defined in a top portion of the display region  11 . Functional devices like a front camera (not shown) and an earphone (not shown) are disposed in the notch  12  in order to prevent the performance of the front camera and the earphone from being negatively influenced by the display region  11 . 
     A disadvantage of the above structure is that a display region needs to be set to a special shape to bypass a location on which the functional devices are disposed, which breaks the integrity of the display region and reduces the screen-to-body ratio of a display panel of a handheld device. 
     To sum up, how to maintain the integrity of the display region and further improve the screen-to-body ratio of the electric product is a technical problem that needs to be solved at present. 
     SUMMARY OF INVENTION 
     To solve the above technical problem, the present invention provides a display panel and a display device, which do not need to be set to a special shape to bypass a location on which functional devices are disposed, which is beneficial to increase the screen-to-body ratio and improve the user experience. 
     To solve the above problem, the present invention provides a display panel including: a light transmission region; a display region covering the light transmission region; a plurality of film layers, wherein at least one of the film layers has a film-free region, an orthographic projection of the film-free region overlaps with an orthographic projection of the light transmission region in a direction perpendicular to the display panel. The film layer having film-free region includes a thin film transistor layer; an organic light-emitting device layer disposed on the thin film transistor layer; and a thin film encapsulation layer covering the organic light-emitting device layer. 
     A width of the film-free region of the organic light-emitting device layer is larger than a width of the film-free region of the thin film encapsulation layer. 
     The width of the film-free region of the thin film encapsulation layer is larger than a width of the film-free region of the thin film transistor layer. 
     The display panel further includes a polarizer disposed on the film layers, wherein the polarizer has an opening. An orthographic projection of the opening of the polarizer overlaps with the orthographic projection of the light transmission region in the direction perpendicular to the display panel. A width of the opening of the polarizer is less than the width of the film-free region of the thin film transistor layer. 
     The display panel further includes a substrate, wherein the substrate has an opening. An orthographic projection of the opening of the substrate overlaps with the orthographic projection of the light transmission region in the direction perpendicular to the display panel. A width of the opening of the substrate is less than the width of the film-free region of the thin film transistor layer. 
     To solve the above problem, the present invention provides a display panel including: a light transmission region; a display region covering the light transmission region; a plurality of film layers, wherein at least one of the film layers has a film-free region. An orthographic projection of the film-free region overlaps with an orthographic projection of the light transmission region in a direction perpendicular to the display panel. 
     In one embodiment, the film layer having the film-free region is an organic light-emitting device layer. 
     In one embodiment, the film layers having the film-free region include an organic light-emitting device layer and a thin film encapsulation layer covering the organic light-emitting device layer. A width of the film-free region of the organic light-emitting device layer is larger than a width of the film-free region of the thin film encapsulation layer. 
     In one embodiment, the film layers having the film-free region include a thin film transistor layer; an organic light-emitting device layer disposed on the thin film transistor layer; and a thin film encapsulation layer covering the organic light-emitting device layer. A width of the film-free region of the organic light-emitting device layer is larger than a width of the film-free region of the thin film encapsulation layer. 
     In one embodiment, the width of the film-free region of the thin film encapsulation layer is larger than the width of the film-free region of the thin film transistor layer. 
     In one embodiment, the display panel further includes a polarizer disposed on the film layers, wherein the polarizer has an opening. An orthographic projection of the opening overlaps with the orthographic projection of the light transmission region in the direction perpendicular to the display panel. A width of the opening is less than the width of the film-free region of the thin film transistor layer. 
     In one embodiment, the display panel further includes a substrate with an opening, an orthographic projection of the opening overlaps with the orthographic projection of the light transmission region in the direction perpendicular to the display panel. A width of the opening is less than the width of the film-free region of the thin film transistor layer. 
     In one embodiment, the thin film transistor layer includes at least one metal layer. The metal layer bypasses a region corresponding to the light transmission region to form the film-free region of the thin film transistor layer. 
     In one embodiment, the display panel further includes a plate covering the film layers. 
     The present invention further provides a display device including the above display panel and a functional device disposed on a non-light-emitting side of the display panel. The functional device has a daylighting region at a side of the functional device toward the display panel. The orthographic projection of the light transmission region overlaps with an orthographic projection of the daylighting region in the direction perpendicular to the display panel. 
     Regarding the beneficial effect of the present invention, display panel and a display device are provided, which do not need to be set to a special shape to provide a notch, which is beneficial to increase the screen-to-body ratio and improve the user experience. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  is a top plan view of a conventional display panel. 
         FIG. 2  is a top plan view of the first embodiment according to the display panel of the present invention. 
         FIG. 3  is a sectional view along a C-C line in  FIG. 2 . 
         FIG. 4  is a sectional view of the second embodiment according to the display panel of the present invention. 
         FIG. 5  is a sectional view of the third embodiment according to the display panel of the present invention. 
         FIG. 6  is a schematic view according to the display panel of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The specific embodiments of the display panel and the display device provided by the present invention will be described in detail below with reference to the accompanying drawings. 
       FIG. 2  is a top plan view of the first embodiment according to the display panel of the present invention.  FIG. 3  is a sectional view of a C-C line in  FIG. 2 . As shown in  FIG. 2  and  FIG. 3 , a display panel  2  includes a display region  20  and a light transmission region  30 . The display region  20  is configured to display an image. The light transmission region  30  is configured to transmit visible light therethrough, that is, visible light can be transmitted from a light-emitting surface of the display panel  2  to a non-light-emitting surface of the display panel  2  in the light transmission region  30 . The display region  20  covers the light transmission region  30 , that is, an edge of the transmission layer  30  is isolated from an edge of the display region  20 . 
     The display panel  2  includes a plurality of film layers. At least one of the film layers has a film-free region. In the present embodiment, the display panel  2  includes a thin film transistor layer  21 ; an organic light-emitting device layer  22  disposed on the thin film transistor layer  21 ; and a thin film encapsulation layer  23  covering the organic light-emitting device layer  22 . The organic light-emitting device layer  22  has a film-free region  22 A. The film-free region  22 A is a region where the organic light-emitting device layer  22  does not form. Specifically, in the process of manufacturing the organic light-emitting device layer  22 , the film-free region  22 A is a predetermined region where the organic light-emitting device layer  22  does not form. 
     An orthographic projection of the film-free region  22 A overlaps with an orthographic projection of the light transmission region  30  in a direction perpendicular to the display panel  2 , in other words, the orthographic projection of the light transmission region  30  is within the orthographic projection of the film-free region  22 A, which can be divided into two cases. For the first case, the orthographic projection of the film-free region  22 A overlaps with the orthographic projection of the light transmission region  30  whereas for the second case, an edge of the orthographic projection of the film-free region  22 A protrudes from an edge of the orthographic projection of the light transmission region  30 . Specifically, according to the present invention, the orthographic projection of the film-free region  22 A overlaps with the orthographic projection of the light transmission region  30 , which means the orthographic projection of the film-free region  22 A overlaps with the orthographic projection of the light transmission region  30  in a Y direction, or means the edge of the orthographic projection of the film-free region  22 A protrudes from the edge of the orthographic projection of the light transmission region  30  in the Y direction. Since the organic light-emitting device layer  22  does not form in a region corresponding to the light transmission region  30 , visible light can be transmitted from the light-emitting surface of the display panel  2  to the non-light-emitting surface of the display panel  2  in the light transmission region  30 . Therefore, a functional device on the non-light-emitting surface of the display panel  2  can be irradiated by visible light. 
     Preferably, in the present embodiment, the display  2  further includes a polarizer  24  disposed on the film layers. Specifically, the polarizer  24  is disposed on the thin film encapsulation layer  23 . The polarizer  24  has an opening  24 A. The opening  24 A can be formed by laser cutting in the process of manufacturing the display  2 . In the direction perpendicular to the display panel  2 , an orthographic projection of the opening  24 A overlaps with the orthographic projection of the light transmission region  30 , which means the orthographic projection of the opening  24 A overlaps with the orthographic projection of the light transmission region  30  in the Y direction, or means an edge of the orthographic projection of the film-free region  24 A protrudes from the edge of the orthographic projection of the light transmission region  30  in the Y direction. Since the transmission  30  is not blocked by the polarizer  24 , visible light can pass through the opening  24 A of the polarizer  24 . 
     In the present embodiment, a width W 1  of the opening  24 A of the polarizer  24  is less than a width W 2  of the film-free region  22 A of the organic light-emitting device  22 , thereby further preventing the organic light-emitting device  22  from being blocked by the light transmission region  30 . 
     The display  2  further includes a substrate  25  and a plate  26 . The substrate  25  is disposed underneath the thin film transistor layer  21 , and the plate  26  covers the film layers. Specifically, in the present embodiment, the plate  26  covers the polarizer  24 . The substrate  25  is a regular substrate like a polyimide (PI) substrate. The plate  26  is a transparent plate like a glass substrate. 
     In the light transmission layer  30  according to the present invention, at least one of the film layers has a film-free region. Since the transmission layer  30  is not blocked by the film layer, visible light transmittance of the layer  30  is increased. Therefore, a functional device on the non-light-emitting surface of the display panel  2  can be irradiated by visible light. 
       FIG. 4  is a sectional view of the second embodiment according to the display panel of the present invention. As shown in  FIG. 4 , in the present embodiment, the display  2  includes a thin film transistor layer  21 ; an organic light-emitting device layer  22  disposed on the thin film transistor layer  21 ; and a thin film encapsulation layer  23  covering the organic light-emitting device layer  22 . The difference between the present embodiment and the first embodiment is that the organic light-emitting device layer  22  has a film-free region  22 A and the thin film encapsulation layer  23  has a film-free region  23 A. The organic light-emitting device layer  22  does not form in the film-free region  22 A, and the thin film encapsulation layer  23  does not form in the film-free region  23 A. 
     A width W 2  of the film-free region  22 A of the organic light-emitting device layer  22  is larger than a width W 4  of the film-free region  23 A of the thin film encapsulation layer  23 . Specifically, the thin film encapsulation layer  23  is configured to cover a surface of the organic light-emitting device layer  22  and an edge of the organic light-emitting device layer  22  toward the film-free region  22 A, thereby protecting a structure of the organic light-emitting device layer  22  from moisture and oxygen in the air. 
       FIG. 5  is a sectional view of the third embodiment according to the display panel of the present invention. As shown in  FIG. 5 , in the present embodiment, the display  2  includes a thin film transistor layer  21 ; an organic light-emitting device layer  22  disposed on the thin film transistor layer  21 ; and a thin film encapsulation layer  23  covering the organic light-emitting device layer  22 . The difference between the present embodiment and the first embodiment is that the organic light-emitting device layer  22  has a film-free region  22 A, the thin film encapsulation layer  23  has a film-free region  23 A, and the thin film transistor layer  21  has a film-free region  21 A. The organic light-emitting device layer  22  does not form in the film-free region  22 A, the thin film encapsulation layer  23  does not form in the film-free region  23 A, and the thin film transistor layer  21  does not form in the film-free region  21 A. 
     In the present invention, a width W 2  of the film-free region  22 A of the organic light-emitting device layer  22  is larger than a width W 4  of the film-free region  23 A of the thin film encapsulation layer  23 . The width W 4  of the film-free region  23 A of the thin film encapsulation layer  23  is larger than a width W 5  of the film-free region  21 A of the thin film transistor layer  21 . Therefore, a top surface, a bottom surface and an edge of the organic light-emitting device layer  22  are covered by the film layers, thereby protecting a structure of the organic light-emitting device layer  22  from moisture and oxygen in the air. 
     Selectively, in the present embodiment, the display  2  further includes a substrate  25  underneath the thin film transistor layer  21 . The substrate  25  has an opening  25 A. In a direction perpendicular to the display panel  2 , an orthographic projection of the opening  25 A overlaps with an orthographic projection of the light transmission region  30 , which means the orthographic projection of the opening  25  of the substrate  25  overlaps with the orthographic projection of the light transmission region  30  in a Y direction, or means an edge of the orthographic projection of the opening  25 A of the substrate  25  protrudes from the edge of the orthographic projection of the light transmission region  30  in the Y direction. Since the transmission  30  is not blocked by the substrate  25 , visible light can pass through the opening  25 A of the substrate  25 . 
     In the present embodiment, a width W 1  of an opening  24 A of the polarizer  35  is less than the width W 2  of the film-free region  22 A of the organic light-emitting device layer  22 , thereby further preventing the light transmission region  30  from being blocked by the organic light-emitting device layer  22 . A width W 3  of the opening  25 A of the substrate  25  is less than the width W 2  of the film-free region  22 A of the organic light-emitting device layer  22 , thereby further preventing the light transmission region  30  from being blocked by the organic light-emitting device layer  22 . The opening  25 A of the substrate  25  and the opening  24 A of the polarizer  24 A can be formed simultaneously by laser cutting in a process of manufacturing the display panel  2 . Therefore, the width W 3  of the opening  25 A of the substrate  25  is equal to the width W 1  of the opening  24 A of the polarizer  24 . 
     Selectively, in the present embodiment, the width W 1  of the opening  24 A of the polarizer  24  is less than a width W 5  of the film-free region  21 A of the thin film transistor layer  21 . The width W 3  of the opening  25 A of the substrate  25  is less than the width W 5  of the film-free region  21 A of the thin film transistor layer  21 . As a result, the transmission region  30  is not blocked by the film layers of the display panel  2 . 
     The thin film transistor layer  21  has a regular structure which can be formed by a combination of at least one metal layer (not shown) and at least one insulating layer (not shown). In the present embodiment, the metal layer bypasses a region corresponding to the light transmission region  30  to form the film-free region  21 A of the thin film transistor layer  21 . Since the insulating layer is made of transparent materials, visible light can pass through the insulating layer. Because visible light can&#39;t pass through the metal layer, the film-free region  21 A is not provided with the metal layer but the insulating layer to prevent visible light from being blocked by the metal layer. In another embodiment according to the present invention, neither the metal layer nor the insulating layer is provided by the film-free region  21 A, thereby further increasing visible light transmittance of the light transmission  30 . 
     The present invention further provides a display device.  FIG. 6  is a schematic view according to the display panel of the present invention. As shown in  FIG. 6 , the display device of the present invention includes the above display panel  2  and a functional device  3 . The functional device  3  is disposed on a non-light-emitting side of the display  2 . A daylighting region  3 A is located on a side of the functional device  3  toward the display  2 . In a direction perpendicular to the display panel  2 , an orthographic projection of the light transmission  30  overlaps with an orthographic projection of the daylighting region  3 A. Specifically, in the present embodiment, the functional device  3  is a camera component, and the daylighting region  30  is a lens of the camera component. An orthographic projection of the transmission  30  overlaps with an orthographic projection of the daylighting region  30 , thereby ensuring the intensity of visible light entering the lens. In other embodiment of the present invention, the functional device  3  can also be other structures that need visible light, which is not limited in the present invention. 
     The above description is only a preferred embodiment of the present invention, and it should be noted that those skilled in the art can also make several improvements and modifications without departing from the principles of the present invention. The improvements and the modifications should also be considered as the scope of the present invention. 
     The present invention can be manufactured and used in the industry, so it possesses industrial practicability.