Patent Publication Number: US-2023139981-A1

Title: Polarizer and display device

Description:
FIELD OF DISCLOSURE 
     The present application relates to the field of display technology, and in particular, to a polarizer and a display device. 
     DESCRIPTION OF RELATED ART 
     Polarizers in conventional display devices are mainly used to convert incident natural light into polarized light. However, with rapid development of optical technology, the polarizers are not limited to having a single function. At present, there is a demand on the market to use OLED displays in sunlight. Color temperatures of the OLED displays decrease after being exposed to sunlight. If the color temperatures decrease too much, the color temperatures of the OLED displays after exposure to ultraviolet light are yellowish. 
     Therefore, there is an urgent need to overcome the present shortcomings. 
     SUMMARY 
     It is an objective of the present application to provide a polarizer and a display device. The polarizer is used in the display device to effectively solve a problem that a color temperature of a display panel drops greatly after irradiation of light of a predetermined wavelength. 
     The present application provides a polarizer, comprising: a polarizing layer and at least one functional layer stacked on the polarizing layer, wherein a light absorber is added in the at least one functional layer to reduce transmittance of light of a predetermined wavelength. 
     Optionally, in some embodiments of the present application, the transmittance of the polarizer to the light of the predetermined wavelength is less than 15%. 
     Optionally, in some embodiments of the present application, the predetermined wavelength ranges from 200 nm to 480 nm. 
     Optionally, in some embodiments of the present application, the functional layer comprises: at least one adhesive layer disposed on one side of the polarizer and connected to a display panel; and at least one protective layer disposed on another side of the polarizer. 
     Optionally, in some embodiments of the present application, the functional layer further comprises a compensation layer; the functional layer comprises two adhesive layers, and the two adhesive layers are a first adhesive layer and a second adhesive layer; the protective layer is arranged on one side of the polarizing layer; the first adhesive layer is disposed on one side of the polarizing layer away from the protective layer; the compensation layer is arranged on one side of the first adhesive layer away from the polarizing layer; the second adhesive layer is disposed on one side of the compensation layer away from the first adhesive layer; and the polarizer is fixed to the display panel through the second adhesive layer. 
     Optionally, in some embodiments of the present application, the protective layer comprises a hardened layer, and the hardened layer is arranged on one side of the protective layer away from the polarizing layer. 
     Optionally, in some embodiments of the present application, the light absorber is added in the hardened layer. 
     Optionally, in some embodiments of the present application, the polarizer further comprises a release film layer, and the release film layer is disposed on one side of the adhesive layer away from the polarizing layer and is detachable to expose the at least one adhesive layer. 
     The present application further provides a display device comprising a display panel and a polarizer, wherein the polarizer is fixed on one side of the display panel, the polarizer comprises a polarizing layer and at least one functional layer stacked on the polarizing layer, and a light absorber is added in the functional layer to reduce transmittance of light of a predetermined wavelength. 
     Optionally, in some embodiments of the present application, the transmittance of the polarizer to the light of the predetermined wavelength is less than 15%. 
     Optionally, in some embodiments of the present application, the predetermined wavelength ranges from 200 nm to 480 nm. 
     Optionally, in some embodiments of the present application, the functional layer comprises: at least one adhesive layer disposed between the polarizer and the display panel; and at least one protective layer disposed on one side of the polarizer away from the display panel. 
     Optionally, in some embodiments of the present application, the functional layer further comprises a compensation layer; the functional layer comprises two adhesive layers, and the two adhesive layers are a first adhesive layer and a second adhesive layer; the protective layer is arranged on one side of the polarizing layer; the first adhesive layer is disposed on one side of the polarizing layer away from the protective layer; the compensation layer is arranged on one side of the first adhesive layer away from the polarizing layer; the second adhesive layer is disposed on one side of the compensation layer away from the first adhesive layer; and the polarizer is fixed to the display panel through the second adhesive layer. 
     Optionally, in some embodiments of the present application, the protective layer comprises a hardened layer, and the hardened layer is arranged on one side of the protective layer away from the polarizing layer. 
     Optionally, in some embodiments of the present application, the light absorber is added in the hardened layer. 
     Optionally, in some embodiments of the present application, a material of the polarizing layer comprises polyvinyl alcohol. 
     Optionally, in some embodiments of the present application, a material of the protective layer comprises at least one of triacetyl cellulose, polymethyl methacrylate, polyethylene terephthalate, or cyclic olefin polymer. 
     Optionally, in some embodiments of the present application, a material of the at least one adhesive layer comprises a pressure sensitive adhesive. 
     Optionally, in some embodiments of the present application, the display device further comprises: a cover plate fixed to one side of the polarizer away from the display panel through an optical adhesive layer, wherein at least one of the optical adhesive layer or the functional layer is added with a light absorber to reduce the transmittance of the light of the predetermined wavelength. 
     Optionally, in some embodiments of the present application, a proportion of the light absorber added in the optical adhesive layer is less than or equal to a proportion of the light absorber added in the functional layer. 
     ADVANTAGE OF THE PRESENT INVENTION 
     Compared with conventional techniques, the polarizer in the present application has the light absorber added in the functional layer to reduce the transmittance of the light of the predetermined wavelength. Specifically, at least one of the first adhesive layer, the second adhesive layer, the protective layer, or the optical adhesive layer is added with the light absorber to reduce the transmittance of light with a wavelength of 200 nm to 480 nm, thus reducing the transmittance to be less than 15%. By using the polarizer in the display device, it can effectively solve the problem that a luminescent material in the display panel changes after being irradiated by the light of the predetermined wavelength, which results in a significant decrease in a color temperature of the display panel. The present application also improves viewing angles as well as relieves a color shift problem and dark-state light leakage, thereby improving display performance of the display panel. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       In order to more clearly illustrate the embodiments of the present application, figures which will be described in the embodiments are briefly introduced hereinafter. It is obvious that the drawings are merely for the purposes of illustrating some embodiments of the present application, and a person having ordinary skill in this field can obtain other figures according to these figures without inventive work. 
         FIG.  1    is a schematic view illustrating a first structure of a display device according to one embodiment of the present application. 
         FIG.  2    is a schematic view illustrating a second structure of the display device according to one embodiment of the present application. 
         FIG.  3    is a schematic view illustrating a third structure of the display device according to one embodiment of the present application. 
         FIG.  4    is a schematic structural view of a polarizer according to one embodiment of the present application. 
         FIG.  5    is another schematic structural view of the polarizer according to one embodiment of the present application. 
         FIG.  6    is a schematic view illustrating a fourth structure of the display device according to one embodiment of the present application. 
     
    
    
     DESCRIPTION OF THE MAIN REFERENCE NUMERALS 
       10  display device;  1221  hardened layer 
       100  polarizer;  130  light absorber 
       110  polarizing layer;  140  compensation layer 
       120  functional layer;  150  release film layer 
       121  adhesive layer;  200  display panel 
       1211  first adhesive layer;  300  optical adhesive layer 
       1212  second adhesive layer;  400  cover plate 
       122  protective layer 
     DETAILED DESCRIPTION OF EMBODIMENTS 
     The technical solutions in embodiments of the present application are clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work shall fall within the protection scope of the present application. In addition, it should be noted that the specific embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In the present application, unless otherwise specified, directional terms such as “up”, “down”, “left”, and “right” can refer to the directions in which a device is actually used or the directions of the device&#39;s working state, or the directional terms can refer to the directions in the drawings, or the direction terms can refer to two opposite directions; and “inner” and “outer” refer to directions with respect to outlines of the device. 
     Specifically, referring to  FIG.  1   , the present application provides a display device  10 , comprising a display panel  200  and a polarizer  100 . The polarizer  100  is fixed on one side of the display panel  200 . The polarizer  100  comprises a polarizing layer  110  and at least one functional layer  120  stacked on the polarizing layer  110 . A light absorber  130  is added to the functional layer  120  to reduce transmittance of light of a predetermined wavelength. The functional layer  120  comprises at least one adhesive layer  121  and at least one protective layer  122 . The at least one adhesive layer  121  is disposed between the polarizer  100  and the display panel  200 . The protective layer  122  is disposed on one side of the polarizer  100  away from the display panel  200 . In the present application, the light absorber  130  is uniformly distributed in the functional layer  120 , which can ensure that the polarizer  100  absorbs the light of the predetermined wavelength uniformly, and improves light transmission uniformity of the polarizer  100 . 
     In the present application, one side of the adhesive layer  121  away from the polarizing layer  110  is used to bond the polarizer  100  to a bonding base. The bonding base can be any display panel or a display cover, etc., and the present embodiment is not limited in this regard. The polarizing layer  110  is a main part of the polarizer  100  that realizes a polarization function. 
     A material of the polarizing layer  110  comprises polyvinyl alcohol (PVA). A thickness of the polarizing layer  110  ranges from 10 um to 30 um, and is, for example, 15 um, 20 um, 25 um, etc. Since the polarizing layer has low strength, brittle and fragile characteristics, and high hydrophilicity, the protective layer  122  is disposed on one side of the polarizing layer to support and protect the polarizing layer  110 , and effectively prevents the polarizing layer  110  from shrinking, deforming, absorbing water, and fading under influence of an ambient environment. In the present embodiment, a surface of the protective layer  122  can also undergo anti-reflection treatment and anti-glare treatment to meet diversified requirements. Those skilled in the art can understand that at least one of the adhesive layer  121  or the protective layer  122  is added with the light absorber  130  to reduce the transmittance of the light of the predetermined wavelength. 
     The present invention mainly absorbs the light of the predetermined wavelength through the light absorber  130 , thereby reducing damage of the light of the predetermined wavelength to the polarizing layer  110  in the polarizer  100  and enhancing stability of the polarizing layer  110 . 
     The predetermined wavelength in the present application ranges from 200 nm to 480 nm. Specifically, the light of the predetermined wavelength comprises: ultraviolet light with a wavelength range of 200 nm to 380 nm and visible light with a wavelength range of 380 nm and 480 nm. For example: the ultraviolet light with a wavelength of 340 nm, the visible light with a wavelength of 400 nm, the visible light with a wavelength of 420 nm, etc. The light absorber  130  reduces transmittance of the ultraviolet light with the wavelength range of 200 nm to 380 nm and transmittance of the visible light with the wavelength range of 380 nm to 480 nm by absorbing the ultraviolet light with the wavelength range of 200 nm to 380 nm and the visible light with the wavelength range of 380 nm to 480 nm, thus further improving an absorption resistance ability of the polarizer  100  against ultraviolet light. The light absorber  130  can make the polarizer  100  have transmittance of less than 15% for the light of the predetermined wavelength. That is to say, for the ultraviolet light with the wavelength range of 200 nm to 380 nm and the visible light with the wavelength range of 380 nm to 480 nm, the transmittance is less than 15%. Preferably, the transmittance of the polarizer  100  to the light of the predetermined wavelength is less than 12%. 
     Those skilled in the art can understand that the specific range of the predetermined wavelength in the present embodiment and the range of the transmittance of the polarizer  100  to the light of the predetermined wavelength can also be used in any embodiment of the present application, and a detailed description is not repeated for brevity. 
     Referring to  FIG.  2   , in one embodiment of the present application, the functional layer  120  further comprises a compensation layer  140 , the functional layer  120  comprises the two adhesive layers  121 , and the two adhesive layers  121  are a first adhesive layer  1211  and a second adhesive layer  1212 . The first adhesive layer  1211  is disposed on one side of the polarizing layer  110 . The compensation layer  140  is disposed on one side of the first adhesive layer  1211  away from the polarizing layer  110 . The second adhesive layer  1212  is arranged on one side of the compensation layer  140  away from the first adhesive layer  1211 . The protective layer  122  is arranged on another side of the polarizing layer  110 . At least one of the first adhesive layer  1211 , the second adhesive layer  1212 , or the protective layer  122  is added with the light absorber  130  to reduce the transmission of the light of the predetermined wavelength. One side of the second adhesive layer  1212  away from the compensation layer  140  is used to bond the polarizer  100  to a bonding base. The bonding base can be any display panel or a display cover, and the present embodiment is not limited in this regard. The compensation layer  140  is configured to provide polarization compensation, which compensates or corrects a phase difference at different viewing angles to a certain extent, thereby improving display image quality through the polarizer  100 . The compensation layer  140  can also improve viewing angles as well as relieves color shift and dark-state light leakage. Those skilled in the art can understand that a position of adding the light absorber  130  in the present embodiment is not limited by  FIG.  2   . The light absorber  130  can also be added in the first adhesive layer  1211  and the protective layer  122 . Preferably, the compensation layer  140  is also integrated with a polarizing brightness enhancement film, which can effectively improve the transmittance of the polarizer  100  to the light of wavelengths other than the predetermined wavelength. 
     Referring to  FIG.  3   , the protective layer  122  in the present application comprises a hardened layer  1221 . The hardened layer  1221  is disposed on one side of the protective layer  122  away from the polarizing layer  110 . It should be noted that the hardened layer  1221  is part of the protective layer  122 . That is to say, the hardened layer  1221  is disposed inside the protective layer  122  and is arranged away from the polarizing layer  110 . Preferably, when the light absorber  130  is added in the protective layer  122 , the light absorber  130  is added in the hardened layer  1221 . The hardened layer  1221  can be disposed in the protective layer  122  in the foregoing embodiments. Specifically, the protective layer  122  can be disposed or can be not disposed with the hardened layer  1221 , and the present application is not limited in this regard. Those skilled in the art can understand that the position of adding the light absorber  130  is not limited by  FIG.  3   . The hardened layer  1221  can be disposed in the protective layer  122  of the polarizer  100  in any embodiment of the present application, and a configuration is not limited to a structure of the polarizer  100  shown in  FIG.  3   . The hardened layer  1221  can enhance hardness, abrasion resistance, and erosion resistance of the polarizer  100 . The hardness of the polarizer  100  provided with the hardened layer  1221  can reach 3H or higher. 
     Referring to  FIG.  4   , the polarizer  100  further comprises a release film layer  150 , and the release film layer  150  is disposed on one side of the adhesive layer  121  away from the polarizing layer  110 . Specifically, the release film layer  150  is disposed on one side of the first adhesive layer  1211  or the second adhesive layer  1212  away from the polarizing layer  110 , and a configuration is not limited to  FIG.  4   . Similarly, the release film layer  150  can be disposed in the polarizer  100  according to any embodiment of the present application, and a configuration is not limited to a structure of the polarizer  100  in  FIG.  4   . The release film layer  150  protects the polarizer  100  and is configured to protect the adhesive layer  121  and prevent the adhesive layer  121  from being exposed to a natural environment and losing its viscosity. A material of the release film layer  150  comprises polyethylene terephthalate (PET). It should be noted that when the polarizer  100  is attached to the display panel  200 , the release film layer  150  is peeled off. At this time, the polarizer  100  after the release film layer  150  is peeled off has the same structure as a structure shown in  FIG.  1   . 
     Referring to  FIG.  5   , in one embodiment of the present application, the functional layer  120  further comprises a compensation layer  140  and a release film layer  150 . The functional layer  120  comprises the two adhesive layers  121  and the protective layer  122 . The two adhesive layers  121  are the first adhesive layer  1211  and the second adhesive layer  1212 . The protective layer  122  is disposed on one side of the polarizing layer  110 . The protective layer  122  comprises a hardened layer  1221 , and the hardened layer  1221  is disposed on one side of the protective layer  122  away from the polarizing layer  110 . The first adhesive layer  1211  is disposed on one side of the polarizing layer  110  away from the protective layer  122 . The compensation layer  140  is disposed on one side of the first adhesive layer  1211  away from the polarizing layer  110 . The second adhesive layer  1212  is disposed on one side of the compensation layer  140  away from the first adhesive layer  1211 . The release film layer  150  is disposed on one side of the second adhesive layer  1212  away from the compensation layer  140 . The light absorber  130  is added in at least one of the first adhesive layer  1211 , the second adhesive layer  1212 , or the protective layer  122  to reduce the transmittance of the light of the predetermined wavelength. Those skilled in the art can understand that the position of adding the light absorber  130  in the present embodiment is not limited by  FIG.  5   . The light absorber  130  can also be added in the first adhesive layer  1211  and the protective layer  122 . As shown in  FIG.  5   , when the polarizer  100  is attached to the display panel  200 , the release film layer  150  is peeled off. After the release film layer  150  is peeled off, the polarizer  100  has the same structure as a structure shown in  FIG.  2   . 
     Please refer to  FIG.  6   . In some embodiments of the present application, the display device  10  further comprises a cover plate  400 . The cover plate  400  is fixed to one side of the polarizer  100  away from the display panel  200  by means of an optical adhesive layer  300 . The light absorber  130  is added in at least one of the optical adhesive layer  300  or the functional layer  120  to reduce the transmittance of the light of the predetermined wavelength. It should be noted that the cover plate  400  and the optical adhesive layer  300  can be disposed in the display device  10  described in any of the above embodiments, and a configuration is not limited to  FIG.  6   . As shown in  FIG.  6   , the light absorber  130  is added in the optical adhesive layer  300 . Those skilled in the art can understand that the position of adding the light absorber  130  in the present embodiment is not limited by  FIGS.  1  to  6   . The light absorber  130  can also be added in the protective layer  122  and the adhesive layer  121 . At least one of the adhesive layer  121 , the protective layer  122 , or the optical adhesive layer  300  is added with the light absorber  130 . Specifically, this relates to the following seven scenarios: the adhesive layer  121  is added with the light absorber  130 ; the protective layer  122  is added with the light absorber  130 ; the optical adhesive layer  300  is added with the light absorber  130 ; the adhesive layer  121  and the protective layer  122  are both added with the light absorber  130 ; the adhesive layer  121  and the optical adhesive layer  300  are both added with the light absorber  130 ; the protective layer  122  and the optical adhesive layer  300  are both added with the light absorber  130 ; and the adhesive layer  121 , the protective layer  122 , and the optical adhesive layer  300  are added with the light absorber  130  at the same time. For details about adding the light absorber  130  to at least one layer in other embodiments of the present application, please refer to the present embodiment, and a detailed description is omitted for brevity. 
     In one embodiment of the present application, the display panel  200  and the cover plate  400  can interchange their positions relative to the polarizer  100 . That is to say, the polarizer  100  is fixed to the cover plate  400  by means of the second adhesive layer  1212 , and the polarizer  100  is fixed to the display panel  200  by means of the optical adhesive layer  300 . In other words, the polarizer  100  only needs to be disposed between the display panel  200  and the cover plate  400 . 
     In one embodiment of the present application, adding the light absorber  130  in the optical adhesive layer  300  only needs to meet photocuring requirements of the optical adhesive layer  300 . Preferably, a proportion of the light absorber  130  added in the optical adhesive layer  300  is less than or equal to a proportion of the light absorber  130  added in the functional layer  120 . The display panel  200  is a conventional display panel in the art, and is preferably an OLED display panel. The optical adhesive layer  300  is a transparent material. The display device  10  is provided with the polarizer  100 , which can effectively solve a problem that a luminescent material in the display panel  200  changes after being irradiated by the light of the predetermined wavelength, resulting in a significant decrease in the color temperature of the display panel  200 . The present application also improves viewing angles as well as relieves color shift and dark-state light leakage, thereby improving display performance of the display panel. 
     In the present application, a material of the protective layer  122  comprises at least one of triacetyl cellulose (TAC), polymethyl methacrylate (PMMA, also known as acrylic), polyethylene terephthalate (PET), or cyclic olefin polymer (COP). The material of the protective layer  122  can also be no retardation TAC (NTR), which is more advantageous for alleviating the problem of dark-state light leakage. The above-mentioned materials all have high strength, heat sensitivity, and high permeability, which improves overall performance of the polarizer  100 . The material of the adhesive layer  121  comprises a pressure-sensitive adhesive, and those skilled in the art can understand that the adhesive layer  121  is a transparent material. 
     Further, the display device  10  can be any product or a device with a display function, such as a liquid crystal panel, a mobile phone, a tablet computer, a television, a monitor, a laptop, a digital photo frame, a navigator, and the like. Other indispensable components of the display device  10  are understood by those of ordinary skill in the art, so a detailed description thereof is omitted here and should not be used as a limitation to the present application. 
     In summary, compared with conventional techniques, the polarizer  100  in the present application has the light absorber  130  added in the functional layer  120  to reduce the transmittance of the light of the predetermined wavelength. Specifically, at least one of the first adhesive layer  1211 , the second adhesive layer  1212 , the protective layer  122 , or the optical adhesive layer  300  is added with the light absorber  130  to reduce the transmittance of the light with the wavelength of 200 nm to 480 nm, thus reducing the transmittance to be less than 15%. By using the polarizer  100  in the display device  10 , it can effectively solve the problem that the luminescent material in the display panel  200  changes after being irradiated by the light of the predetermined wavelength, which results in the significant decrease in the color temperature of the display panel  200 . Accordingly, the present application also improves the viewing angles as well as relieves the color shift and the dark-state light leakage, thereby improving the display performance of the display panel. 
     In the above-mentioned embodiments, the description of each embodiment has its own emphasis. For those that are not described in detail in one embodiment, reference may be made to related descriptions of other embodiments. 
     The above describes in detail the display device  10  of the present application. Specific examples are used in the present disclosure to describe the principles and the embodiments of the present application. The description of the above embodiments is only for ease of understanding the approach of the present application and its main ideas. According to the ideas of the present application, those skilled in the art can change the embodiments and their applications. In summary, the content of this specification should not be construed as a limitation to the present application.