Patent Publication Number: US-2023152614-A1

Title: Display device

Description:
BACKGROUND OF INVENTION 
     Field of Invention 
     The present invention relates to a field of display technology, and more particularly, to a display device. 
     Description of Prior Art 
     Currently, liquid crystal displays (LCDs) are widely used in high-definition digital televisions, desktop computers, personal digital assistants (PDAs), notebook computers, digital cameras and other electronic devices. 
     Especially in a field of small and medium-sized liquid crystal displays, under-screen sensor technology and transparent display technology have become developed in the industry. 
     In under-screen sensor technology, a special design of backlight module is required. For example, a common backlight module is paired with a transparent backlight module, so that signal light can reach a sensor area under the screen through the transparent backlight module to realize corresponding recognition function. However, when the transparent backlight module is simply used to provide backlight for the sensor area under the screen, light diverges severely, which causes brightness of this area to be dark, resulting in uneven viewing angles. 
     Therefore, there is an urgent need to provide a display device to solve the above-mentioned technical problems. 
     SUMMARY OF INVENTION 
     A display device provided to solves the above-mentioned technical problems that the use of a transparent backlight module in a conventional display device easily causes uneven viewing angles when displaying images in the under-screen sensor technology. 
     A display device comprises: 
     a display panel including at least one display sensing area and a main display area surrounding the display sensing area; 
     a first backlight module including an optical element, and at least a part of the optical element completely faces the display sensing area, and the optical element is configured to switch between a fog state and a transparent state; 
     a second backlight module disposed corresponding to the main display area; 
     a light sensor disposed on a side of the first backlight module away from the display panel and corresponding to the display sensing area; and 
     a viewing angle adjusting component disposed between the display panel and the light sensor and corresponding to the display sensing area, and the viewing angle adjusting component comprises a dimming area and a light transmitting area that are alternately arranged at intervals; 
     when the optical element is in the fog state, the viewing angle adjusting component is configured to adjust the exit angle of the backlight passing through the viewing angle adjusting component; and when the optical element is in the transparent state, external light enters the light sensor through the viewing angle adjusting component and the first backlight module, and the light sensor functions. 
     In one embodiment, the viewing angle adjusting component comprises: 
     a first substrate;
 
a second substrate disposed opposite to the first substrate;
 
     a transparent medium layer disposed between the first substrate and the second substrate, and the transparent medium layer is provided with a plurality of first through holes at intervals, and the plurality of first through holes are filled with a liquid crystal dye layer to form a dimming structure, the liquid crystal dye layer comprises liquid crystal molecules and dye molecules; 
     a first electrode disposed on a side of the first substrate facing the second substrate; and 
     a second electrode disposed on a side of the second substrate facing the first substrate; 
     when the optical element is in the fog state, a longitudinal axis of the liquid crystal molecules in plurality of dimming structures are perpendicular to the first substrate; and when the optical element is in the transparent state, the longitudinal axis of the liquid crystal molecules in plurality of the dimming structures are parallel to the first substrate. 
     In one embodiment, the first electrode comprises a plurality of first sub-electrodes arranged at intervals, the second electrode comprises a plurality of second sub-electrodes arranged at intervals, and each of the first sub-electrodes is arranged corresponding to one of the second sub-electrodes, and a plurality of the first sub-electrodes and a plurality of the second sub-electrodes are disposed corresponding to a plurality of the dimming structures. 
     In one embodiment, the transparent medium layer further comprises a plurality of second through holes, each of the second through holes intersects and communicates with a plurality of the first through holes; a plurality of the first through holes and the second through holes are filled with the liquid crystal molecules and the dye molecules to form the dimming structure. 
     In one embodiment, an orthographic projection of each of the first through holes on the transparent medium layer is elongated and extends in a first direction, and an orthographic projection of each of the second through holes on the transparent medium layer is elongated and extends in a second direction; and the first direction and the second direction are perpendicular to each other. 
     In one embodiment, a shrinking viewing angle adjusted by the viewing angle adjusting component is θ=arctan[(p−w)/h], and w is a width of the first through hole, p is a period length of the first through hole, and h is a height of the first through hole. 
     In one embodiment, the liquid crystal molecules are positive liquid crystal molecules or negative liquid crystal molecules, and the dye molecules are positive dye molecules or negative dye molecules. 
     In one embodiment, the viewing angle adjusting component is located on a side of the optical element close to the display panel, and the optical element is located between the viewing angle adjusting component and the light sensor. 
     In one embodiment, the viewing angle adjusting component is located on a side of the optical element away from the display panel, and the viewing angle adjusting component is located between the optical element and the light sensor. 
     In one embodiment, the optical element is disposed corresponding to the main display area and the display sensing area. 
     A display device comprises: 
     a display panel including at least one display sensing area and a main display area surrounding the display sensing area; 
     a first backlight module including an optical element, and at least a part of the optical element completely faces the display sensing area, and the optical element is switched between a fog state and a transparent state; 
     a second backlight module disposed corresponding to the main display area; 
     a light sensor disposed on a side of the first backlight module away from the display panel and corresponding to the display sensing area; and 
     a viewing angle adjusting component disposed between the display panel and the light sensor and corresponding to the display sensing area; 
     when the optical element is in the fog state, the viewing angle adjusting component is configured to adjust the exit angle of the backlight passing through the viewing angle adjusting component; and when the optical element is in the transparent state, external light enters the light sensor through the viewing angle adjusting component and the first backlight module, and the light sensor functions. 
     In one embodiment, the viewing angle adjusting component comprises: 
     a first substrate; 
     a second substrate disposed opposite to the first substrate; 
     a transparent medium layer disposed between the first substrate and the second substrate, and the transparent medium layer is provided with a plurality of first through holes at intervals, and the plurality of first through holes are filled with a liquid crystal dye layer to form a dimming structure, the liquid crystal dye layer comprises liquid crystal molecules and dye molecules; 
     a first electrode disposed on a side of the first substrate facing the second substrate; and 
     a second electrode disposed on a side of the second substrate facing the first substrate; 
     when the optical element is in the fog state, a longitudinal axis of the liquid crystal molecules in plurality of dimming structures are perpendicular to the first substrate; and when the optical element is in the transparent state, the longitudinal axis of the liquid crystal molecules in plurality of the dimming structures are parallel to the first substrate. 
     In one embodiment, the first electrode comprises a plurality of first sub-electrodes arranged at intervals, the second electrode comprises a plurality of second sub-electrodes arranged at intervals, and each of the first sub-electrodes is arranged corresponding to one of the second sub-electrodes, and a plurality of the first sub-electrodes and a plurality of the second sub-electrodes are disposed corresponding to a plurality of the dimming structures. 
     In one embodiment, the transparent medium layer further comprises a plurality of second through holes, each of the second through holes intersects and communicates with a plurality of the first through holes; a plurality of the first through holes and the second through holes are filled with the liquid crystal molecules and the dye molecules to form the dimming structure. 
     In one embodiment, an orthographic projection of each of the first through holes on the transparent medium layer is elongated and extends in a first direction, and an orthographic projection of each of the second through holes on the transparent medium layer is elongated and extends in a second direction; and the first direction and the second direction are perpendicular to each other. 
     In one embodiment, a shrinking viewing angle adjusted by the viewing angle adjusting component is θ=arctan[(p−w)/h], and w is a width of the first through hole, p is a period length of the first through hole, and h is a height of the first through hole. 
     In one embodiment, the liquid crystal molecules are positive liquid crystal molecules or negative liquid crystal molecules, and the dye molecules are positive dye molecules or negative dye molecules. 
     In one embodiment, the viewing angle adjusting component is located on a side of the optical element close to the display panel, and the optical element is located between the viewing angle adjusting component and the light sensor. 
     In one embodiment, the viewing angle adjusting component is located on a side of the optical element away from the display panel, and the viewing angle adjusting component is located between the optical element and the light sensor. 
     In one embodiment, the optical element is disposed corresponding to the main display area and the display sensing area. 
     The viewing angle adjusting component comprises an optical element, which can switch between the fog state and the transparent state. When the optical element is in the fog state, the viewing angle adjusting component can reduce the exit angle of the backlight through the viewing angle adjusting component, which improves the uniformity of the backlight viewing angle of the first backlight module, so as to improve the display effect. When the optical element is in the transparent state, external light enters the light sensor through the viewing angle adjusting component and the first backlight module to perform the function of the light sensor. Without affecting the function of the light sensor, the uniformity of the backlight viewing angle of the first backlight module and the display effect are improved. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       In order to explain the technical solutions in the embodiments of the present invention more clearly, the following will briefly introduce the accompanying drawings needed in the description of the embodiments. Obviously, the accompanying drawings in the following description are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative work. 
         FIG.  1    is a schematic structural view of a first display device according to one embodiment of the present invention. 
         FIG.  2    is a simplified structural view of a viewing angle adjusting component when an optical element is in a fog state according to one embodiment of the present invention. 
         FIG.  3    is a schematic structural view of an optical element of a first viewing angle adjusting component in the fog state according to one embodiment of the present invention. 
         FIG.  4    is a schematic structural view of the optical element of the first viewing angle adjusting component in a transparent state according to one embodiment of the present invention. 
         FIG.  5    is a schematic structural view of an optical element of a second viewing angle adjusting component in the transparent state according to one embodiment of the present invention. 
         FIG.  6    is a schematic structural view of the optical element of the second viewing angle adjusting component in the fog state according to one embodiment of the present invention. 
         FIG.  7    is a first schematic structural top view of a transparent medium layer according to one embodiment of the present invention. 
         FIG.  8    is a second schematic structural top view of the transparent medium layer according to one embodiment of the present invention. 
         FIG.  9    is a schematic structural view of a second display device according to one embodiment of the present invention. 
         FIG.  10    is a schematic structural view of a third display device according to one embodiment of the present invention. 
         FIG.  11    is a schematic structural view of a fourth display device according to one embodiment of the present invention. 
         FIG.  12    is a schematic structural view of a fifth display device according to one embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The description of the following embodiments refers to the attached drawings to illustrate specific embodiments that can be implemented in the present application. The directional terms mentioned in this application, such as “top,” “down,” “front,” “back,” “left,” “right,” “inner,” “outer,” “side,” etc., are only for reference in the direction of the attached drawings. Therefore, the directional terms used are used to illustrate and understand the present application, rather than to limit the present application. In the drawings, units with similar structures are indicated by the same reference numerals. 
     Referring to  FIG.  1   , it is a schematic structural view of a first display device according to one embodiment of present invention. 
     A display device comprises a display panel  1 , a first backlight module  2 , a second backlight module  3 , a light sensor  4 , and a viewing angle adjusting component  5 . The display panel  1  comprises at least one display sensing area  101  and a main display area  102  surrounding the display sensing area  101 . The main display area  102  refers to an area mainly used to display images, and the display sensing area  101  refers to an area used to collect optical signals. The light sensor  4  may be a camera, a fingerprint recognition sensor, or other sensors, so that the display device can realize functions such as photographing and optical fingerprint recognition. 
     The first backlight module  2  comprises an optical element  21 . At least a part of the optical element  21  completely faces the display sensing area  101 , and the optical element  21  is configured to switch between a fog state and a transparent state. The optical element  21  may be a polymer dispersed liquid crystal (PDLC) dimming film or a polymer network liquid crystal (PNLC). The second backlight module  3  is disposed corresponding to the main display area  102 . When the optical element  21  is in the fog state, the viewing angle adjusting component  5  is configured to adjust the exit angle of the backlight passing through the viewing angle adjusting component  5 . When the optical element  21  is in the transparent state, external light enters the light sensor  4  through the viewing angle adjusting component  5  and the first backlight module  2 , and the light sensor  4  functions. 
     It can be understood that the first backlight module  2  further comprises a first light source  22 , and the second backlight module  3  comprises an optical film set  31  and a second light source  32 . When the display device performs normal display, the optical element  21  is configured to switch to the fog state, the first light source  22  and the second light source  32  are both turned on, so the optical element  21  functions as a light guide plate, and the backlight emitted by the first light source  22  sequentially passes through the optical element  21  and the viewing angle adjusting component  5 , and then injects into the display panel  1 . The light emitted by the second light source  32  enters the display panel  1  through the optical film set  31 . At this time, the display sensing area  101  and the main display area  102  both perform image display, which can realize full-screen display. 
     Referring to  FIG.  2   , it is a simplified structural view of the viewing angle adjusting component when the optical element is in the fog state according to one embodiment of the present invention. 
     The viewing angle adjusting component  5  comprises a dimming area  501  and a light transmitting area  502  that are alternately arranged at intervals. 
     When the optical element  21  is configured to switch to the fog state, the backlight emitted by the first light source  22  passes through the viewing angle adjusting component  5 , the dimming area  501  which is opaque, and the light transmitting area  502  which is transparent, so that the exit direction of the backlight can be reduced, and the output caused by the first backlight can be reduced. The large viewing angle light intensity caused by the first backlight module  2  is conducive to shrink the viewing angle, thereby forming a uniform backlight for normal display. 
     When the light sensor  4  is working, the optical element  21  is configured to switch to the transparent state, the first light source  22  is turned off, the second light source  32  is turned on, and the backlight emitted by the second light source  32  enters the display panel  1  through the optical film set  31 . When ambient light passes through the viewing angle adjusting component  5 , both the dimming area  501  and the light transmitting area  502  are transparent, and the ambient light can reach the light sensor  4  through the optical element  21  and the viewing angle adjusting component  5 . At this time, the main display area  102  performs image display, while the display sensing area  101  does not perform image display, and it can be used to realize functions such as taking pictures, so as to improve the uniformity of the backlight viewing angle of the first backlight module  2  without affecting the function of the light sensor  4 , thereby improving the display effect. 
     Referring to  FIG.  3    to  FIG.  6   , the viewing angle adjusting component  5  comprises a first substrate  51 , a second substrate  52 , a liquid crystal dye layer  53 , a first electrode  54 , a second electrode  55 , and a transparent medium layer  56 . The first substrate  51  and the second substrate  52  are disposed opposite to each other. The transparent medium layer  56  is disposed between the first substrate  51  and the second substrate  52 . The transparent medium layer  56  is provided with a plurality of first through holes  561  arranged at intervals. The first through holes  561  are filled with the liquid crystal dye layer  53  to form a dimming structure  562 , and the liquid crystal dye layer  53  comprises liquid crystal molecules  531  and dye molecules  532 . The first electrode  54  is disposed on a side of the first substrate  51  facing the second substrate  52 , and the second electrode  55  is disposed on a side of the second substrate  52  facing the first substrate  51 . 
     Specifically, the first substrate  51  and the second substrate  52  are both transparent substrates, such as transparent glass substrates. The first electrode  54  and the second electrode  55  are both transparent electrodes. For example, the material of the first electrode  54  and the second electrode  55  may be transparent conductive materials such as indium tin oxide and indium zinc oxide. 
     It should be noted that the liquid crystal molecules  531  may simply refer to general indicator liquid crystal molecules, or may refer to polymer liquid crystals with a low polymer concentration. The liquid crystal molecules  531  are positive liquid crystal molecules or negative liquid crystal molecules, and the dye molecules  532  are positive dye molecules or negative dye molecules, including the following combinations, for example, the combination of positive liquid crystal molecules and positive dye molecules, the combination of negative liquid crystal molecules and negative dye molecules, the combination of positive liquid crystal molecules and negative dye molecules, and the combination of negative liquid crystal molecules and positive dye molecules. The dye molecules  532  are dichroic dye molecules, which absorb visible light differently along the longitudinal axis and the short axis. For positive dye molecules, when polarization direction of visible light being parallel to the longitudinal axis direction of the dye molecules  532  is incident on the dye molecules  532 , the absorption rate of the dye molecules  532  for visible light reaches the maximum, and the light is almost completely absorbed. When polarization direction of the visible light being perpendicular to the longitudinal axis direction of the dye molecules  532  is incident on the dye molecules  532 , the dye molecules  532  have almost no impact on the visible light. 
     As for negative dye molecules, when polarization direction of visible light being parallel to the longitudinal axis direction of the dye molecules  532  is incident on the dye molecules  532 , the dye molecules  532  have almost no effect on the visible light. When polarization direction of the visible light being perpendicular to the longitudinal axis direction of the dye molecules  532  is incident on the dye molecules  532 , the absorption rate of the dye molecules  532  for visible light reaches the maximum, and the light is almost completely absorbed. 
     The liquid crystal dye layer  53  is filled with the liquid crystal molecules  531  and the dye molecules  532 , the dye molecules  532  and the liquid crystal molecules  531  are aligned in the same direction, and the longitudinal axis directions of the two are parallel to each other in the initial state. When the longitudinal axis direction of the liquid crystal molecules  531  rotates under an electric field, the longitudinal axis of the dye molecules  532  also rotates due to the guest-host effect. 
     The viewing angle adjusting component  5  provided by the embodiments of the present invention utilizes the above-mentioned properties of the liquid crystal molecules  531  and the dye molecules  532  to control the inversion of the liquid crystal molecules  531  through an electric field, and drive the dye molecules  532  to invert, so as to realize the dual-controllable state including a wide viewing angle mode and a narrow viewing angle mode, so that the normal display mode and the light sensor working mode do not interfere with each other. 
     Furthermore, the viewing angle adjusting component  5  further comprises a first alignment film and a second alignment film (not shown in the figure) for controlling the initial alignment direction of the liquid crystal molecules  531 . The first alignment film is disposed on a side of the first electrode  54  facing the second substrate  52 , and the second alignment film is disposed on a side of the second electrode  55  facing the first substrate  51 . The alignment directions of the first alignment film and the second alignment film are the same, and may be horizontal alignment or vertical alignment. When the first alignment film and the second alignment film are in a horizontal alignment, the initial alignment direction of the liquid crystal molecules  531  is the same as direction of the longitudinal axis of the liquid crystal molecules  531  which is parallel to the first substrate  51 . When the first alignment film and the second alignment film are vertically aligned, the initial alignment direction of the liquid crystal molecules  531  is such that the longitudinal axis of the liquid crystal molecules  531  is perpendicular to the first substrate  51 . 
     It should be noted that whether a voltage is applied to the first electrode  54  and the second electrode  55  to control the alignment direction of the liquid crystal molecules  531  depends on the alignment direction of the first alignment film and the second alignment film and the properties of the liquid crystal molecules  531 , and it can be a combination of the two, for example, the liquid crystal molecules  531  are positive liquid crystal molecules, and the first alignment film and the second alignment film are horizontally aligned; the liquid crystal molecules  531  are negative liquid crystal molecules, the first alignment film and the second alignment film are horizontally aligned; the liquid crystal molecules  531  are positive liquid crystal molecules, and the first alignment film and the second alignment film are vertically aligned; the liquid crystal molecules  531  are negative liquid crystal molecules, and the first alignment film and the second alignment film are vertically aligned. 
     For the convenience of description, the embodiment of the present invention adopts the liquid crystal molecules  531  as positive liquid crystal molecules, and the first alignment film and the second alignment film are horizontally aligned as an example for explanation. For the working principle of the viewing angle adjusting component adopting the other cases listed above, please refer to the specific description about this case, and the embodiments of the present invention will not be detailed one by one. 
     Referring to  FIG.  3    and  FIG.  5   , when the optical element  21  is in the fog state, a longitudinal axis of the liquid crystal molecules  531  in a plurality of the dimming structures  562  are perpendicular to the first substrate  51 . Due to the guest-host effect, the longitudinal axis of the dye molecules  532  in the plurality of the dimming structures  562  is perpendicular to the first substrate  51 , and a part of the backlight emitted by the first light source  22  will be absorbed by the dye molecules  532  in the dimming structures  562  and cannot pass through the viewing angle adjusting component  5 , and thus it can achieve the purpose of narrowing the viewing angle. At this time, the viewing angle adjusting component  5  is in the narrow viewing angle mode. 
     In the narrow viewing angle mode, first, the display sensing area  101  can display images, and a better viewing angle effect can be obtained. Next, when the viewer views from a side of the display panel  1 , the brightness of the screen is attenuated, and the screen becomes more blurred when viewed obliquely, and the display screen cannot be seen by the viewer, which can improve the anti-peeping effect. Furthermore, the viewing angle adjusting component  5  can absorb the backlight provided by the first backlight module  2  which enters the boundary between the main display area  102  and the display sensing area  101 , and overcomes the viewing angle mismatch between the second backlight module  3  and the viewing angle adjusting component  5 , which results in poor display effect, and thus the problem of the large viewing angle of the first backlight module  2  can be solved. 
     Referring to  FIG.  4    and  FIG.  6   , when the optical element  21  is in the transparent state, the longitudinal axis of the liquid crystal molecules  531  in plurality of the dimming structures  562  is parallel to the first substrate  51 . Due to the guest-host effect, the longitudinal axis of the dye molecules  532  in the plurality of the dimming structures  562  is parallel to the first substrate  51 , and the dye molecules  532  in the plurality of the dimming structures  562  do not affect the backlight emitted by the first light source  22 . At this time, the viewing angle adjusting component  5  is in the wide viewing angle mode. 
     In the wide viewing angle mode, the display sensing area  101  does not display images, which can effectively prevent the normal operation of the light sensor  4  from being affected. At this time, the viewing angle adjusting component  5  does not have any interference effect on the light sensor  4 . The viewing angle adjusting component  5  can further diverge the ambient light. For example, when the light sensor  4  is a camera, it can reduce the brightness of the light during shooting, so as to reduce the impact on the imaging. 
     It is understandable that the liquid crystal dye layer  53  is disposed in a partial area between the first substrate  51  and the second substrate  52 , and the first electrode  54  and the second electrode  55  of the present invention can be disposed in sections or on the entire surface. 
     In one embodiment, referring to  FIG.  3    and  FIG.  4   , the first electrode  54  is disposed on a side of the first substrate  51  facing the second substrate  52 , and the second electrode  54  is disposed on a side of the second substrate  52  facing the first substrate  51 . In this embodiment, the first electrode  54  and the second electrode  55  are disposed on the entire surface, which can reduce steps of manufacturing process. 
     Referring to  FIG.  3   , when the optical element  21  is in the fog state, the first electrode  54  and the second electrode  55  are energized, and a vertical electric field is formed between the first electrode  54  and the second electrode  55 . The liquid crystal molecules  531  in the plurality of the dimming structures  562  rotate under the vertical electric field, so that the longitudinal axis of the liquid crystal molecules  531  in the plurality of the dimming structures  562  is perpendicular to the first substrate  51 . Due to the guest-host effect, the dye molecules  532  in the plurality of the dimming structures  562  rotate accordingly, and finally the longitudinal axis of the dye molecules  532  in the plurality of the dimming structures  562  is perpendicular to the first substrate  51 . Therefore, part of the backlight emitted by the first light source  22  is absorbed by the dye molecules  532  in the dimming structures  562 , and cannot pass through the viewing angle adjusting component  5 , so that the objective of narrowing the viewing angle can be achieved. At this time, the viewing angle adjusting component  5  is in the narrow viewing angle mode. 
     Referring to  FIG.  4   , when the optical element  21  is in the transparent state, the first electrode  54  and the second electrode  55  are not energized, the longitudinal axis of the liquid crystal molecules  531  in the plurality of the dimming structures  562  is parallel to the first substrate  51 , and the longitudinal axis of the dye molecules  532  in the plurality of the dimming structures  562  is parallel to the first substrate  51 . Therefore, the dye molecules  532  in the plurality of the dimming structures  562  have no influence on the backlight emitted by the first light source  22 . At this time, the viewing angle adjusting component  5  is in the wide viewing angle mode. 
     In another embodiment, as shown in  FIG.  5    and  FIG.  6   ,  FIG.  5    and  FIG.  6    are different from  FIG.  3    and  FIG.  4    in that: the first electrode  54  in  FIG.  5    and  FIG.  6    is disposed in sections on a side of the first substrate  51  facing the second substrate  52 , and the second electrode  55  is disposed in sections on a side of the second substrate  52  facing the first substrate  51 , which can save material and save product cost. Specifically, the side of the first substrate  51  facing the second substrate  52  is provided with a first electrode  54 , and the side of the second substrate  52  facing the first substrate  51  is provided with a second electrode  55 . 
     The first electrode  54  comprises a plurality of first sub-electrodes  541  arranged at intervals, the second electrode  55  comprises a plurality of second sub-electrodes  551  arranged at intervals, and each of the first sub-electrodes  541  is arranged corresponding to one of the second sub-electrodes  551 , and the plurality of first sub-electrodes  541  and the plurality of second sub-electrodes  551  are disposed corresponding to the plurality of the dimming structures  562 . 
     Referring to  FIG.  5   , when the optical element  21  is in the fog state, the first electrode  54  and the second electrode  55  are energized, and an electric field is formed between the first electrode  54  and the second electrode  55 . The liquid crystal molecules  531  in the plurality of the dimming structures  562  rotate under the electric field, so that the longitudinal axis of the liquid crystal molecules  531  in the plurality of the dimming structures  562  is perpendicular to the first substrate  51 . Due to the guest-host effect, the dye molecules  532  in the plurality of the dimming structures  562  rotate accordingly, and finally the longitudinal axis of the dye molecules  532  in the plurality of the dimming structures  562  is perpendicular to the first substrate  51 . Therefore, part of the backlight emitted by the first light source  22  is absorbed by the dye molecules  532  in the dimming structures  562 , and cannot pass through the viewing angle adjusting component  5 , so that the objective of narrowing the viewing angle can be achieved. At this time, the viewing angle adjusting component  5  is in the narrow viewing angle mode. 
     Referring to  FIG.  6   , when the optical element  21  is in the transparent state, the first electrode  54  and the second electrode  55  are not energized, the longitudinal axis of the liquid crystal molecules  531  in the plurality of the dimming structures  562  is parallel to the first substrate  51 , and the longitudinal axis of the dye molecules  532  in the plurality of the dimming structures  562  is parallel to the first substrate  51 . Therefore, the dye molecules  532  in the plurality of the dimming structures  562  have no influence on the backlight emitted by the first light source  22 . At this time, the viewing angle adjusting component  5  is in the wide viewing angle mode. 
     Specifically, the display device shown in  FIG.  3    is taken as an example for description. The embodiment of the present invention can improve the viewing angle shrinkage of the viewing angle adjusting component  5  by designing different aspect ratios of the first through holes  561 . For example, define a width of the first through holes  561  as w, and a period length of the first through holes  561  is p, a height of the first through holes  561  is h, and an aspect ratio of the first through holes  561  is h/w, so the contraction viewing angle θ=arctan[(pw)/h], it can be seen that the shrinking viewing angle θ of the viewing angle adjusting component  5  depends on the aspect ratio of the first through holes  561 , and different aspect ratios can be designed according to actual needs. 
     Referring to  FIG.  7   , an orthographic projection of the first through holes  561  on the transparent medium layer  56  is elongated and extends along a first direction x. A cross-sectional shape of the first through holes  561  may be a rectangle. 
     Furthermore, referring to  FIG.  8   , the difference between  FIG.  8    and  FIG.  7    is that the transparent medium layer  56  further comprises a plurality of second through holes  563 , and each of the second through holes  563  crosses and communicates with a plurality of first through holes  561 . A cross-sectional shape of the second through holes  563  may be a rectangle. 
     The first through holes  561  and the second through holes  563  are filled with the liquid crystal molecules  531  and the dye molecules  532  to form the dimming structure  562 . When the optical element  21  is in the fog state, part of the backlight emitted by the first light source  22  will be absorbed by the dye molecules  532  in the dimming structure  562  corresponding to the first through holes  561  and the second through holes  563 , which can further reduce the viewing angle. 
     The display device also comprises an upper polarizer and a lower polarizer (not shown in the figure). The upper polarizer is disposed on a side of the display panel  1  away from the first backlight module  2 , and the lower polarizer is disposed on a side of the display panel  1  close to the first backlight module  2 . The lower polarizer is disposed between the display panel  1  and the viewing angle adjusting component  5 . In the transparent state, the longitudinal axis of the dye molecules  532  is parallel to a polarization direction of the lower polarizer, so the backlight absorption is not affected under large viewing angles. 
     There are many situations for the placement position of the viewing angle adjusting component  5 , which will be explained one by one below. 
     In one embodiment, referring to  FIG.  1   ,  FIG.  9   , and  FIG.  10   , the viewing angle adjusting component  5  is located on a side of the optical element  21  close to the display panel  1 , and the optical element  21  is located between the viewing angle adjusting component  5  and the light sensor  4 . In the fog state, the light emitted by the first light source  22  propagates inside the optical element  21 , then is adjusted by the viewing angle adjusting component  5 , and finally enters the display panel  1  to achieve image display. In the transparent state, the ambient light passes through the viewing angle adjusting component  5  and the optical element  21  in order, and then enters the light sensor  4 . 
     In one embodiment, referring to  FIG.  11    and  FIG.  12   , the viewing angle adjusting component  5  is located on a side of the optical element  21  away from the display panel  1 , and the viewing angle adjusting component  5  is located between the optical element  21  and the light sensor  4 . In the fog state, the light emitted by the first light source  22  is adjusted by the viewing angle adjusting component  5 , then enters the optical element  21  to propagate, and finally enters the display panel  1  to achieve image display. In the transparent state, the ambient light passes through the viewing angle adjusting component  5  and the optical element  21  in order, and then enters the light sensor  4 . 
     The first light source  22  may be an edge-lit backlight. For example, referring to  FIG.  1   , the first light source  22  is disposed on a side of the optical element  21 . For another example, referring to  FIG.  9   ,  FIG.  10   ,  FIG.  11   , and  FIG.  12   , the first light source  22  may also be a direct type backlight source, and the first light source  22  is disposed on a side of the optical element  21  away from the display panel  1 . 
     Furthermore, referring to  FIG.  10    and  FIG.  12   , the optical element  21  can be disposed corresponding to the main display area  102  and the display sensing area  101 . The orthographic projection of the optical element  21  on the display panel  1  overlaps with the orthographic projection of the optical film set  31  on the display panel  1 , which can make the viewing angle difference at the junction of the main display area  102  and the display sensing area  101  easier to handle, and thus it prevents other defects such as black spots on the screen. In this case, the first light source  22  may be a direct type backlight source to prevent affecting the normal display brightness of the main display area  102  during switching when an edge type backlight source is adopted. 
     The beneficial effect is that the display device provided by the embodiment of the present invention adopts the viewing angle adjusting component and first backlight module that can switch the viewing angle, and arranging the two in the display sensing area of the display panel, so as to solve the problem in the under-screen sensor technology that conventional display devices adopt a transparent backlight module, which easily causes uneven viewing angles when the picture is displayed. 
     The viewing angle adjusting component comprises an optical element, which can switch between the fog state and the transparent state. When the optical element is in the fog state, the viewing angle adjusting component can reduce the exit angle of the backlight through the viewing angle adjusting component, which improves the uniformity of the backlight viewing angle of the first backlight module, so as to improve the display effect. When the optical element is in the transparent state, external light enters the light sensor through the viewing angle adjusting component and the first backlight module to perform the function of the light sensor. Without affecting the function of the light sensor, the uniformity of the backlight viewing angle of the first backlight module and the display effect are improved. 
     In the above, the present application has been described in the above preferred embodiments, but the preferred embodiments are not intended to limit the scope of the invention, and a person skilled in the art may make various modifications without departing from the spirit and scope of the application. The scope of the present application is determined by claims.