Patent Publication Number: US-11657640-B2

Title: Display panel and display device having imaging aperture formed on color filter layer

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to a Chinese patent application No. CN202010142721.1, entitled “Display Panel And Display Device” and filed on Mar. 4, 2020, the content of which is incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     The present disclosure relates to the field of display technology, and in particular, to a display panel and a display device. 
     BACKGROUND 
     Everyone is characterized with fingerprints. With the development of science and technology, various display devices with fingerprint recognition functions, such as mobile phones, tablet computers and smart wearable devices, have appeared on the market. Before a user operates a display device with the fingerprint recognition function, the user can perform permission verification by simply touching the display device with a finger, so that the permission verification process is simplified. Moreover, with the gradual increase of the application scenarios of the fingerprint recognition function, the fingerprint recognition region gradually evolves from a partial region to a full screen. 
     In the related display device which is based on optical fingerprint recognition technology, an optical sensor is often formed on a semiconductor device in the display device. Fingerprint detection is implemented by using a feature that is when certain semiconductor device is exposed to light, the device may generate a leakage current. Specifically, after light generated by a fingerprint recognition light source is reflected on a surface where a finger touches the display device, the reflected light hits the optical sensor and the optical sensor detects the light intensity caused by the fluctuations of fingerprint valleys and peaks to generate a fingerprint image. However, the accuracy of fingerprint recognition in the related art needs to be further improved. 
     Therefore, how to improve the accuracy of fingerprint recognition on a display device needs to be solved. 
     SUMMARY 
     The present disclosure provides a display panel, including a substrate having a first surface and a second surface opposing the first surface, an array layer, a display layer, a color filter layer, a protective layer, first metal parts and an optical sensor layer. The array layer is disposed on the first surface of the substrate, and the display layer is disposed on a side of the array layer facing away from the substrate and includes light-emitting elements. The color filter layer is disposed on a side of the display layer facing away from the array layer. The color filter layer includes a light-blocking layer and color filters. The color filters are in correspondence with the light-emitting elements. The light-blocking layer includes first light-blocking portions, each forming an imaging aperture. The protective layer is disposed on the color filter layer. Each first metal part overlaps a respective first light-blocking portion of the light-blocking layer. The optical sensor layer is disposed on a side of the color filter layer facing away from the protective layer and configured to detect an image formed by the imaging aperture. The present disclosure further provides a display device including the display panel. 
     The benefit of the disclosed display device improves the imaging effect of the imaging aperture, enhances the quality of the imaging picture and increases the accuracy of the optical recognition. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a top view of a display panel according to an embodiment of the present disclosure; 
         FIG.  2    is a partial cross sectional view taken along A-A′ of  FIG.  1   ; 
         FIG.  3    is a top view of a color filter layer of a display panel according to an embodiment of the present disclosure; 
         FIG.  4    is a top view of another display panel according to an embodiment of the present disclosure; 
         FIG.  5    is a partial enlarged view of the display panel of  FIG.  4   ; 
         FIG.  6    is a cross sectional view taken along B-B′ of the display panel of  FIG.  5   ; 
         FIG.  7    is another partial enlarged view of the display panel of  FIG.  4   ; 
         FIG.  8    is another partial cross sectional view taken along A-A′ of  FIG.  1   ; 
         FIGS.  9 - 12    are cross sectional views of various display panels according to embodiments of the present disclosure; 
         FIG.  13    is a top view of another display panel according to an embodiment of the present disclosure; and 
         FIG.  14    is a structural diagram of a display device. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure will be further described in conjunction with drawings and embodiments. 
     It should be noted that in the following description, details are described to provide a thorough understanding of the present disclosure. The present disclosure can, however, be implemented in various other manners than those described herein and those skilled in the art may make similar generalizations without departing from the meaning of the present disclosure. Therefore, the present disclosure is not limited by the embodiments disclosed below. 
     The terminology used in embodiments of the present disclosure is for describing specific embodiments only and is not intended to limit the present disclosure. As used in the present disclosure and the appended claims, singular forms “a, an” and “the” are also intended to include plural forms unless the context clearly indicates other meanings. 
     It should be noted that directional terms such as “upper”, “lower”, “left” and “right” described in embodiments of the present disclosure are described at the angle shown in the drawings and should not be construed as limiting the present disclosure. Further, in the context, it should be understood that when an element is referred to be formed “on” or “under” another element, the element can be formed not only directly “on” or “under” another element, but the element is also possible to be formed indirectly “on” or “under” another element through an intermediate element. 
     Moreover, example embodiments can be implemented in various manners and should not be construed as being limited to the embodiments provided herein. Rather, these embodiments are provided so that the present disclosure is more thorough and complete and the concept of the example embodiments is fully conveyed to those skilled in the art. In the drawings, the same reference numerals denote the same or similar structures, and thus a repeated description of the same reference numerals will be omitted. Words denoting positions and orientations described in the present disclosure are illustrated by examples of drawings, but changes may be made as required, and the changes are contained within the scope of the present disclosure. The drawings of the present disclosure are only used for illustrating relative positional relationships, the layer thicknesses at certain locations have been drawn exaggeratedly to facilitate understanding, and the layer thicknesses in the drawings do not represent proportional relationships of the actual layer thicknesses. Moreover, if not in conflict, embodiments of the present disclosure and features thereof may be combined with each other. The drawings of embodiments of the present application have the same reference numerals. Further, similarities between the embodiments are not repeated here. 
       FIG.  1    is a top view of a display panel according to an embodiment of the present disclosure.  FIG.  2    is a partial cross sectional view taken along A-A′ of  FIG.  1   , and the cross section shows the device in a perpendicular view to the plane where the display panel is located. 
     In  FIG.  1   , the display panel  100  is divided into a display region AA and a non-display region NA surrounding the display region AA. It should be understood that a dotted box in  FIG.  1    is used for illustrating a boundary between the display region AA and the non-display region NA. The display region AA is a region of the display panel for displaying images. The display region AA typically includes pixel units arranged in an array. Each pixel unit includes a light-emitting element (for example, a diode) and a control element (for example, a thin-film transistor constituting a pixel driving circuit) corresponding to the pixel unit. The non-display region NA surrounds the display region AA and typically includes a peripheral drive element, peripheral wiring and a fan-out region. 
     The display panel  100  includes a substrate  110 . The substrate  110  (that is, the substrate base) may be flexible and thus extensible, collapsible, bendable or rollable, so that the flexible display panel may be extensible, collapsible, bendable or rollable. The substrate  110  may be formed by any suitable insulating material with flexibility. The substrate  110  is used for blocking oxygen and moisture, preventing diffusion of moisture or impurities through the flexible substrate, and providing a flat surface on an upper surface of the flexible substrate. For example, the substrate  110  may be formed by a polymer material such as polyimide (PI), polycarbonate (PC), polyether sulfone (PES), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyarylate (PAR) or glass fiber reinforced plastic (FRP). The substrate  110  may be transparent, translucent or opaque. In an embodiment, the display panel may further include a buffer layer (not shown) on the substrate  110 , and the buffer layer may cover the entire upper surface of the substrate  110 . 
     The display panel  100  further includes an array layer  200  located on the substrate  110 . The array layer  200  is located on a side of the substrate  110  facing toward a display surface or touch surface of the display panel  100 . The array layer  200  may include multiple thin film transistors (TFTs)  210  and a pixel circuit constituted by the TFTs. The pixel circuit is used for controlling light-emitting elements in the display layer. 
     This embodiment utilizes top-gate thin film transistors as an example to illustrate the structure. A thin film transistor layer  210  includes an active layer  211  located on the substrate  110 . The active layer  211  may include a material such as amorphous silicon, polysilicon or metal oxide. When the active layer  211  is the polysilicon material, it may be made by the technology of low temperature amorphous silicon, that is, the amorphous silicon material is melted by a laser and deposited to form the polysilicon material. Moreover, various methods such as a rapid thermal annealing (RTA) method, a solid phase crystallization (SPC) method, an excimer-laser annealing (ELA) method, a metal induced crystallization (MIC) method, a metal induced lateral crystallization (MILC) method or a sequential lateral solidification (SLS) method may be used. The active layer  211  further includes a source region and a drain region formed by doping N-type impurity ions or P-type impurity ions, and a channel region formed between the source region and the drain region. 
     The display panel  100  further includes a gate insulating layer  212  located on the active layer  211 . The gate insulating layer  212  includes an inorganic layer such as silicon oxide or silicon nitride, and may include a single layer or multiple layers. 
     The display panel  100  further includes gates  213  located on the gate insulating layer  212 . The gate  213  may include a single layer or multiple layers made from metal such as gold (Au), silver (Ag), copper (Cu), nickel (Ni), platinum (Pt), palladium (Pd), aluminum (Al), molybdenum (Mo) or chromium (Cr), or made from alloy such as aluminum (Al): neodymium (Nd) alloy and molybdenum (Mo): tungsten (W) alloy. 
     The display panel  100  further includes an interlayer insulating layer  214  located on the gates  213 . The interlayer insulating layer  214  may be formed by an inorganic insulating material such as silicon oxide or silicon nitride. Of course, in other embodiments of the present disclosure, the interlayer insulating layer  214  may be made from an organic insulating material. 
     The display panel  100  further includes source electrodes  2151  and drain electrodes  2152  located on the interlayer insulating layer  214 . The source electrode  2151  and drain electrode  2152  are electrically connected (or bonded) to the source region and the drain region respectively through contact holes, and the contact holes are formed by selectively removing the gate insulating layer  212  and the interlayer insulating layer  214 . 
     The array layer  200  may further include a passivation layer  220 . In an embodiment, the passivation layer  220  is located on the source electrodes  2151  and the drain electrodes  2152  of the thin film transistors  210 . The passivation layer  220  may be made from an inorganic material such as silicon oxide or silicon nitride, or may be made from an organic material. 
     The display panel  100  may further include a second planarization layer  230 . In an embodiment, the second planarization layer  230  is located on the passivation layer  220 . The second planarization layer  230  includes an organic material such as acryl, PI, or benzocyclobutene (BCB). The second planarization layer  230  has a planarization function. 
     The display panel  100  further includes a display layer  300  located on a side of the array layer  200  facing away from the substrate  110 . The display layer  300  includes light-emitting elements. In an embodiment, the display layer  300  is located on the second planarization layer  230 . The display layer  300  includes anode layers  310 , organic light-emitting materials  320 , and cathode layers  330  sequentially disposed in a direction facing away from the substrate  110 . The display layer  300  further includes a pixel definition layer  340  located on a side of the anode layers  310  facing away from the array layer  200 . The pixel definition layer  340  may be made from an organic material such as PI, polyamide, BCB, acryl resin or phenolic resin, or made from an inorganic material such as SiNx. 
     In an embodiment, the anode layer  310  includes multiple anode patterns in one-to-one correspondence with the pixels, and the anode pattern in the anode layer  310  is connected to the source electrode  2151  or the drain electrode  2152  of the thin film transistor  210  through a via in the second planarization layer  230 . The pixel definition layer  340  includes multiple openings exposing the anode layers  310 , and the pixel definition layer  340  covers the edge of the patterns of the anode layers  310 . The organic light-emitting material  320  at least partially fills the opening of the pixel definition layer  340  and contacts the anode layer  310 . 
     In  FIG.  2   , the anode layer  310 , the organic light-emitting material  320  and the cathode layer  330  defined by each opening of the pixel definition layer  340  constitute a light-emitting element  350  (that is shown in a dotted box), each light-emitting element  350  may emit light of different colors according to different organic light-emitting materials  320 . Each light-emitting element  350  constitutes a pixel (or each light-emitting element and a pixel circuit controlling the light-emitting element jointly constitute a pixel), and multiple pixels jointly display an image. 
     The organic light-emitting materials  320  may be formed in the openings of the pixel definition layer  340  by the way of inkjet printing, nozzle printing or evaporation. The cathode layer  330  may be formed on the film of the organic light-emitting material  320  by evaporation. In an embodiment, the cathode layer  330  may also integrally cover the organic light-emitting material  320  and the pixel definition layer  340 . 
     The display panel  100  further includes an encapsulation layer  400  located on the display layer  300  and the encapsulation layer  400  integrally covers the display layer  300  to seal the display layer  300 . It should be understood that “on” mentioned in this embodiment may be understood as being “on a side facing away from the substrate  110 ”. The he encapsulation layer  400  is a thin film encapsulation layer located on the cathode layers  330  and includes a first inorganic encapsulation layer, a first organic encapsulation layer and a second inorganic encapsulation layer sequentially arranged in the direction facing away from the substrate  110 . Of course, in other embodiments of the present disclosure, the encapsulation layer  400  may include any number of stacked organic and inorganic materials as required, but include at least one layer of organic material and at least one layer of inorganic material deposited alternately, and the lowermost layer and uppermost layer are made from inorganic materials. 
     The display panel  100  further includes a color filter layer  500  located on a side of the display layer  300  facing away from the array layer  200 . The color filter layer  500  includes a light-blocking layer  510  and color filters  520 . 
       FIG.  3    shows a top view of a color filter layer of the display panel according to the embodiment of the present disclosure. The region filled with dot patterns is the region covered by the light-blocking layer  510 , and the region encircled by the rounded rectangle is the region covered by the color filters  520 . 
     The light-blocking layer  510  is a black matrix (BM). The light-blocking layer  510  may be a grid structure, meshes of the grid are disposed in correspondence with the light-emitting elements  350 , and one mesh defines one color filter  520 . The color filters  520  with different colors are separated by the light-blocking layer  510 . The color filters  520  are in one-to-one correspondence with the light-emitting elements  350 . The color filters  520  include color filters with different colors, and the color filter  520  and the light-emitting element  350  corresponding to each other are in the same color. 
     It should be noted that the correspondence between two elements here may be understood as orthographic projections of the two elements overlapping on the substrate. 
     The display panel  100  may further include a protective layer  600  located on the color filter layer  500 . In an embodiment, the protective layer  600  is the outermost film of the display panel  100  and may be a protective cover or a cover film. The protective layer  600  may be adhered to an adjacent film inside the display panel  100  by an optically clear adhesive (OCA). 
     The light-blocking layer  510  includes first light-blocking portions  511  (the regions encircled by the dotted circle in  FIG.  2    and  FIG.  3   ), and the first light-blocking portion  511  forms an imaging aperture  502 . 
     The display panel  100  further includes first metal parts  700 , and the first metal part  700  overlaps at least the first light-blocking portion  511  of the light-blocking layer  510 . 
     In other words, the first metal part  700  overlaps at least the edge of the light-blocking layer  510  at the imaging aperture  502 , does not overlap the imaging aperture  502 , and does not cover the imaging aperture  502 . It should be understood that the overlapping described here may be a direct contact overlapping. 
     The display panel  100  further includes an optical sensor layer  800  located on a side of the color filter layer  500  facing away from the protective layer  600  and configured to detect an image formed by the imaging aperture  502 . 
     It should be understood that the case where one film is located on a side of another film includes the case where the two films are in contact and the case where the two films are in non-contact. The case of non-contact includes the case where the two films are spaced apart by a certain distance, and the case where other films are spaced apart between the two films. 
     The imaging effect of the imaging aperture  502  can be improved, the quality of imaging pictures can be enhanced, and the accuracy of the optical recognition can be increased. The imaging aperture  502  is formed through the first light-blocking portions  511  of the light-blocking layer  510  of the color filter layer  500 , so that an additional light-blocking layer for fingerprint recognition imaging does not need to be added, which is advantageous for thinning. Meanwhile, in combination with the design that the first metal part  700  overlaps at least the region of the light-blocking layer  510  surrounding the imaging aperture  502 , the blocking effect of the light-blocking layer  510  is consolidated to make the edge of the image presented by the imaging aperture  502  clearer and more definite. 
     The first metal part  700  is located on the lower side of the light-blocking layer  510 , so that the light reflection of the first metal part  700  and pattern visibility can be avoided while the definition and accuracy of pinhole imaging are increased. 
     The light-blocking layer  510  further includes a second light-blocking portion  512 , and the first light-blocking portion  511  is located between the second light-blocking portion  512  and the imaging aperture  502 . 
     The thickness of the second light-blocking portion  512  is greater than the thickness of first light-blocking portion  511 . It should be understood that the thickness described here is the dimension of the light-blocking layer  510  in a direction perpendicular to the substrate  110  (that is the Z-direction in  FIG.  2   ). 
     The light-blocking layer  510  is made from an organic material. The light-blocking layer  510  made from the organic material is easy to pattern, easy to manufacture, has a good film-forming effect, and has a wide selection of materials. 
     Moreover, to have a good light-blocking effect or an effect of separating the color filters, the thickness of the light-blocking layer  510  is large. The organic material is easier to make a light-blocking layer with a large thickness and a small stress. 
     Moreover, to ensure that the imaging aperture  502  penetrates through the light-blocking layer  510 , sufficient patterning is needed. Due to different patterning intensities of different depth positions of the light-blocking layer  510  (for example, taking time as an example, different depth positions have different exposure levels, etch rates and the like), the side wall of the imaging aperture  502  formed by the light-blocking layer  510  may be imaged to a slope. 
     The region covered by the slope is the region where the first light-blocking portion  511  is located. The thickness of the region is smaller than the thickness of the second light-blocking portion  512 . The thickness of the first light-blocking portion  511  is thin, so that the blocking performance is poor, and the edge of the image presented by the imaging aperture is blurred or interfered. 
     That is, only the aperture of the light-blocking layer  510  is used as the imaging aperture  502 . Because the light-blocking layer  510  is made from an organic material, has a small edge angle and an OD value of a large region may be low, a real image formed by the aperture actually has larger “halo”, and the imaging effect is influenced. 
     The imaging effect of the imaging aperture can be improved, the quality of the imaging picture can be enhanced, and the accuracy of the optical recognition can be increased. The imaging aperture  502  is formed through the first light-blocking portions  511  of the light-blocking layer  510  of the color filter layer  500 , so that an additional light-blocking layer for fingerprint recognition imaging does not need to be added, which is advantageous for thinning. Meanwhile, in combination with the design that the first metal part  700  overlaps at least the region of the light-blocking layer  510  surrounding the imaging aperture  502 , the blocking effect of the light-blocking layer is consolidated to make the edge of the image presented by the imaging aperture  502  clearer and more definite. Moreover, the light transmission at the edge of the imaging aperture caused by the thin light-blocking layer and insufficient blocking is improved, and the image quality is enhanced, while the performance of the light-blocking layer in the color filter layer and the manufacturing yield of the imaging aperture are ensured. 
     Referring to  FIG.  4    to  FIG.  6   .  FIG.  4    is a top view of another display panel according to an embodiment of the present disclosure.  FIG.  5    is a partial enlarged view of the display panel of  FIG.  4   .  FIG.  6    is a cross sectional view taken along B-B′ of the display panel of  FIG.  5   . The cross sectional view is perpendicular to the plane where the display panel is located. The similarities between this structure and the other above-mentioned structures will not be described in detail. 
     Differently, the display panel  100  further includes a touch functional layer  900  located between the display layer  300  and the light-blocking layer  510 . The first metal parts  700  are in the same layer with at least one film in the touch functional layer  900 . 
     The touch functional layer  900  is located on a side surface of the encapsulation layer  400  facing away from the display layer  300 , and the touch functional layer  900  may include a stacked touch electrode layer and an insulating layer. 
     The touch functional layer  900  includes a touch drive electrode and a touch sense electrode to form a mutual-capacitance touch functional layer. The touch electrode is directly formed by using the encapsulation layer  400  as a bearing substrate. The touch structure is on-cell. 
     The touch functional layer  900  includes a first touch electrode layer, an insulating layer and a second touch electrode layer sequentially stacked, so that the mutual-capacitance touch function may be implemented. The materials of the first touch electrode layer and the second touch electrode layer may be metal such as molybdenum, copper or nano-silver, or indium tin oxide (ITO). The insulating layer may include at least one organic insulating layer, at least one inorganic insulating layer, or a combination of at least one organic insulating layer and at least one inorganic insulating layer. The organic insulating layer may include a PET insulating layer, and the inorganic insulating layer may include a silicon nitride insulating layer, a silicon oxide insulating layer or a zirconium oxide insulating layer. The mutual-capacitance touch functional layer may be provided with electrodes in different directions on the two touch electrode layers, and the electrodes on the two touch electrode layers are perpendicular to each other. Because the electrodes on the two touch electrode layers are framed on different surfaces, a capacitor node is formed at an intersection of the two touch electrode layers. One touch electrode layer may be used as a driving layer, and the other touch electrode layer may be used as a sensing layer. When current flows through one wire in the driving layer, if a signal of capacitance change exists outside, the change of the capacitance node on the other wire is caused. The change of the detected capacitance value may be measured through the sensing layer and an electronic loop connected to the sensing layer, and touch positioning is carried out according to the measured sensing signal. A self-capacitance touch electrode may also be provided in embodiments of the present disclosure and will not be described here in detail. 
     The first metal parts  700  are in the same layer with at least one film in the touch functional layer  900 . That is, the first metal parts  700  and films also made from a metal material in the touch functional layer  900  are made from the same material and in the same layer. 
     The touch electrode layer is made from a metal material, and the first metal parts  700  and the touch electrode layer are made from the same material and in the same layer. 
     The touch functional layer  900  includes at least one touch electrode layer  910 , and the touch electrode layer  910  includes a touch electrode formed by a metal mesh. In an embodiment, meshes of the metal mesh correspond to the light-emitting elements. 
     The mesh lines of the metal mesh are located in a region covered by the light-blocking layer  510 . Therefore, the interference of light reflected by the metal mesh on the display can be avoided, and the electrode pattern can be avoided being visible. 
     In this structure, the edge definition of pinhole imaging is improved while the number of films and the manufacturing process are not increased. The imaging aperture  502  is formed through the first light-blocking portions  511  of the light-blocking layer  510  of the color filter layer  500 . The film in the first metal parts  700  and the film in the touch functional layer  900  which are made from the metal material are made from the same material and in the same layer. An additional light-blocking layer for fingerprint recognition imaging does not need to be added, and a metal layer does not need to be additionally added for providing the first metal parts, which is advantageous for implementing the thinning of the display panel. Moreover, the combination of the touch functional layer  900  and the color filter layer  500  provided by the present disclosure may also ensure that the first metal parts  700  and the touch electrode cannot reflect light, resulting in the damage of the display effect or the pattern visibility. 
       FIG.  7    is another partial enlarged view of the display panel of  FIG.  4   . The touch functional layer  900  includes at least one touch electrode layer  910 , and the touch electrode layer  910  includes a touch electrode formed by a metal mesh. In an embodiment, meshes of the metal mesh correspond to the light-emitting elements. 
     At least part of the touch electrode  910  is multiplexed as the first metal parts  700 . That is, the touch electrode  910  is integrally formed with the first metal parts  700 . Thus, the process can be simplified, the cost can be reduced, the touch electrode  910  can be integrated with the first metal parts  700 , and the space occupied by the first metal parts  700  can be reduced. 
       FIG.  8    is another partial cross sectional view taken along A-A′ of  FIG.  1    and the section is perpendicular to the plane where the display panel is located. 
     Different from the above mentioned examples, the display panel  100  includes a first planarization layer  620  between the first metal parts  700  and the light-blocking layer  510 . In an embodiment, after the touch functional layer  900  is fabricated, the first planarization layer  620  fabricated by an organic insulating material is covered. The color filter layer  500  is then fabricated on the first planarization layer  620 . The color filter layer  500  may be attached to the first planarization layer  620  after fabricated on other platforms. The first planarization layer  620  may provide a flat surface for the attachment to facilitate fabrication. 
     Moreover, the reliability of the first metal layer being multiplexed as the touch electrode can also be improved. Because the materials of the light-blocking layer are conductive, if the first metal layer is part of the touch electrode, short circuits may be caused between different touch electrodes through the light-blocking layer. The structure can avoid stringent requirements on the materials of the light-blocking layer, which will be easier to find. 
     In all above figures,  FIG.  2   ,  FIG.  6   ,  FIG.  8 - 12   , the cross sectional view is perpendicular to the plane where the display panel is located. 
     The first light-blocking portion  511  is in contact with and covers the first metal part  700 . That is, the first metal parts  700  are under the light-blocking layer  510 , and the two films are adjacent to each other and in direct contact with each other. Therefore, the situation that other films between the first metal part layer and the first light-blocking portions  511  need masks can be avoided, a mask can be saved, and the manufacturing process can be simplified. The pattern of the first metal part layer and the pattern of the first light-blocking portions are basically consistent, and a space can be provided for leading out signals on the display panel  100 . Moreover, the first light-blocking portion  511  is in contact with and covers the first metal part  700 , and no gap exists between the light-blocking portion  511  and the first metal part  700 , so that the blocking effect can be improved, and the accuracy of imaging of the imaging aperture can be refined. 
     In an embodiment, referring to  FIG.  9    or  FIG.  11   , an edge of the first light-blocking portion  511  where the imaging aperture  502  is located is terminated at the first metal part  700 . That is, the first metal part  700  forms a metal edge for the imaging aperture  502 . 
     When the first light-blocking portions  511  of the light-blocking layer  510  are formed, the first metal part  700  may form a dam-like structure to intercept and trap the material of the light-blocking layer  510 , causing the material of the light-blocking layer  510  around the imaging aperture  502  to be thickened. In addition, the first metal part  700  can also cushion the first light-blocking portion  511 , so that the thickness of the light-tight structure formed by the light-blocking layer  510  around the imaging aperture  502  can be indirectly increased, and the imaging effect of the imaging aperture can be improved. 
     As shown in any of  FIG.  10    to  FIG.  12   , the color filter  520  covers the imaging aperture  502 . In an embodiment, the color filter  520  at least partially overlaps the light-blocking layer  510  and overlaps the imaging aperture  502  formed by the first light-blocking portion  511  of the light-blocking layer  510 , causing the color filter  520  fills the imaging aperture  502 . It should be noted that to ensure that the light transmission of the imaging aperture  502 , one imaging aperture  502  is covered by only one color filter  520 . 
     In this structure, light can be ensured to pass through the imaging aperture  502 , and the pattern visibility caused by light reflection of the first metal part  700  can be avoided. Even if light reflected by the first metal part  700  from the side of the aperture can be blocked by the color filter  520 . 
     In  FIG.  12   , at least two imaging apertures  502  are respectively covered by color filters  520  with two different colors. Therefore, images imaged by different imaging apertures  502  are formed by lights of different colors, and interference among the lights transmitted by different imaging apertures  502  is avoided. 
     In an embodiment, the optical sensor layer  800  detects images presented by imaging apertures  502  covered by color filters  520  with different colors at different times. 
     In an embodiment, the optical sensor layer  800  includes multiple sensors arranged in an array and in one-to-one correspondence with the imaging apertures  502 . In an embodiment, the display panel  100  further includes a control unit (not shown), the control unit controls the light source to emit light of different colors at different times, and the control unit controls a detection unit in correspondence with the imaging aperture  502  filled by the color filter  520  with the color to detect the image presented by the imaging aperture  502 . For example, in the first time period, a red light source emits light, and a detection unit in correspondence with an imaging aperture  502  filled by a red color filter captures an image; in the second time period, a green light source emits light, and a detection unit in correspondence with an imaging aperture  502  filled by a green color filter captures an image. The accuracy of light sensing detection is thus increased. 
       FIG.  13    is a top view of another display panel according to another embodiment of the present disclosure. Every three light-emitting elements adjacent to each other in the display panel are arranged in a delta shape. The imaging aperture  502  is located in a middle of the delta shape formed by the three light-emitting elements. 
     The pixels in the display panel  100  are arranged in the delta shape. That is, the light-emitting elements in the display panel  100  are arranged along a first direction X to form pixel rows, and the pixel rows are arranged along a second direction Y to form a pixel array. Red, green and blue pixels are alternately arranged in the first direction X. Adjacent light-emitting elements (pixels) in the second direction Y are arranged in a staggered arrangement. That is, one light-emitting element is arranged at a position corresponding to the position between two light-emitting elements in the adjacent row of pixels and is different in color from the two pixels. Three adjacent pixels form one pixel unit (as indicted by the region encircled by the dotted box). The three pixels of the one pixel unit are arranged in the delta shape, and one pixel of the one pixel unit is equivalent to one corner of the delta shape. One imaging aperture  502  is located in the middle of the delta shape formed by the three light-emitting elements. That is, the imaging aperture  502  is surrounded by the three pixels of the pixel unit. 
     The aperture provided by the imaging aperture  502  can be enlarged, the blocking effect on the pixel light emission is relatively small, and the opening of the pixel cannot be compressed while the imaging aperture  502  is provided. 
     The area of the red pixel of the pixel unit is smaller than pixels with other colors, that is, the area of red color filter is smaller than the area of color filters with other colors. It is limited that the mesh of the red color filter in the light-blocking layer  510  is the smallest. 
     The red pixel is located at a position that is not adjacent to the other two pixels of the same pixel unit in the first direction X, that is, at a position of the upper “corner” of the delta shape. 
     Therefore, the space provided with the imaging aperture  502  can be further increased, and the display effect of the pixels can be improved. 
     Referring to  FIG.  13   , the imaging aperture  502  is in the shape of a triangle, and an orientation of a vertex angle of the triangle is opposite to the orientation of the delta shape. That is, the bottom side of the triangular imaging aperture  502  is parallel to the first direction X, and the bottom side is adjacent to the pixel of the upper “corner” of the delta shape. The vertex angle of the triangular imaging aperture  502  opposite to the bottom side points a position between two pixels adjacent in the first direction X in the pixel unit. 
     The pixel design is matched with the shape and position of the imaging aperture, so that the imaging effect and layout effect of the imaging aperture are improved. 
     It should be understood that the shape here is the shape presented by the top view of the display panel, that is, the shape of the orthographic projection of the component on the substrate. 
     Referring to  FIG.  5    or  FIG.  7   , the first metal part  700  is a closed pattern surrounding the imaging aperture  502 . Thus the light leakage in different directions can be effectively blocked. In addition, it is advantageous for the stability of the structure of the imaging aperture  502  and forming a structure similar to the edge of the imaging aperture  502 . In an embodiment, the first metal part  700  is a closed circle surrounding the imaging aperture  502 , which is advantageous for the stress release. 
     Moreover, for any of the above embodiments, the display panel may further include a fingerprint recognition device, and the fingerprint recognition device includes the optical sensor layer  800  described above. 
     The display panel  100  in the present disclosure may be an organic light-emitting display panel. The light-emitting elements may be multiplexed as the light source of the fingerprint recognition device (the optical sensor layer  800 ) to ensure that the display panel does not need to provide a separate light source for the fingerprint recognition device, the display panel has a simple structure and a simple layer relationship. Thus, the thin and light design of the display panel is easy to be implemented. Alternatively, the display panel provided by the embodiment of the present disclosure may further include a fingerprint recognition light source (not shown). The fingerprint recognition light source separately provides a light source for the optical sensor layer  800  to ensure that the fingerprint recognition device may have multiple functions. For example, the fingerprint recognition light source may be an infrared light source, to ensure that the fingerprint recognition device can not only recognize fingerprints, but also recognize blood flow conditions of human body and monitor human health. 
       FIG.  14    shows the outline  1000  of a mobile phone. It should be understood that the display device  1000  requires a display device  100  with a display function, such as a computer, a television or an in-vehicle display device, which is not limited in the present disclosure. The display device  1000  has the beneficial effects of the display panel  100  provided by the embodiment of the present disclosure. Reference may be made to the detailed description of the display panel  100  in the above embodiments, and these beneficial effects will not be repeated in this embodiment.