Patent Publication Number: US-2021187912-A1

Title: Impact resistant glass screen protector

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates to transparent covers, overlays or protectors to overlay displays of portable electronic devices. 
     Background Art 
     Glass screen protectors have existed for displays. However, the protectors of the past have been used primarily for scratch protection and have not included structure to address impacts or prevent the release of the underlaying glass in the event of the display shattering. They are not typically designed to help absorb the impact energy associated with a drop event—glass is brittle and extremely inelastic, so during a collision impact energy will either be transferred through the glass protector to the display or absorbed by the glass of the protector, resulting in it shattering. If the impact is severe enough, the display of the device may also be harmed. 
     Laminated impact resistant screen protectors have also existed, but the screen protectors of the past have not included a glass layer exposed as the exterior layer for the user to interact with. Such an exposed layer gives the user a tactile feel and response similar to the original display of smart phones that utilize a glass exterior surface for the display. 
     SUMMARY OF THE INVENTION 
     The invention is a multi-layered screen protector. Such a screen protector may be considered a sacrificial protector to prevent damage to the electronic device. The invention includes layers of material and adhesives to provide suitable optical clarity, as well as impact and scratch resistance. The overlays protect the display screen from impacts by providing a cushion and in the case of an impact that is sever enough to break the glass, contains the glass. The layers of the laminate may include tempered glass, optically clear adhesive, thermoplastic polyurethane, UV printing, and double sided adhesives. The layers may be coextensive with each other, or they may overlie portions of the layers above or below. In most embodiments, it is preferred that the layer of tempered glass is dimensionally similar to the display glass of the display it protects, but such construction is not necessary for the invention. 
     The invention disclosed herein also reduces the likelihood of the device display glass shattering during a drop or other impact event. The invention is an improvement of the prior art by adding a TPU and anti-explosion glue or adhesive layer affixed to the rear of the screen protector display glass. These additional layers enhance the impact protection offered by the screen protector by providing a cushioning, shock absorbent layers. In the event of the glass failing/shattering, the broken components are safer to handle through improved containment of the fractured glass fragments, which remain bonded to the TPU and anti-explosion layers as opposed to separating/scattering. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a multi-layer screen protector applied to a phone display, the phone display removed from the phone for illustrative purposes. 
         FIG. 2  is a cross-sectional view of the screen protector of  FIG. 1 . 
         FIG. 1A  is a cross-sectional view of a screen protector applied to a phone with a curved display. 
         FIG. 3  is a perspective view of a screen protector having a glass layer, a TPU layer, and an adhesive layer applied to a display of a phone. 
         FIG. 4  is a cross-sectional view of the screen protector of  FIG. 3 . 
         FIG. 5  is a perspective view of a screen protector having a glass layer, an adhesive layer which may be an anti-explosion layer, and TPU layer, and an adhesive layer applied to a display of a phone. 
         FIG. 6  is a cross-sectional view of the screen protector of  FIG. 5 . 
         FIG. 7  is a perspective view of a screen protector having a glass layer, TPU layer, a UV printing layer, and an adhesive layer applied to a display of a phone. 
         FIG. 8  is a cross-sectional view of the screen protector of  FIG. 7 . 
         FIG. 9  is a perspective view of a screen protector having a glass layer, an optically clear adhesive layer, TPU layer, an anti-explosion adhesive layer, and a perimeter adhesive layer applied to a display of a phone. 
         FIG. 10  is a cross-sectional view of the screen protector of  FIG. 9 . 
         FIG. 11  is a perspective view of a screen protector having a glass layer, an optically clear adhesive layer or anti-explosion layer, a TPU layer, a UV printed layer, and a perimeter adhesive layer applied to a display of a phone. 
         FIG. 12  is a cross-sectional view of the screen protector of  FIG. 11 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to the figures, in one embodiment, the invention discloses a laminated screen protector  100  for a mobile electronic device  10  having a display  11 . The screen protector may be generally flat, or it may be curved as shown in  FIG. 1A . 
     The screen protector may include in some embodiments, an outwardly facing glass layer  110 . The glass layer  110  may be co-extensive or nearly coextensive with the display  11  of the mobile electronic device  10 . In the most preferred embodiment, the glass layer  110  is 0.33 mm thick, but the thickness may vary. 
     The glass layer  110  may be tempered glass, Sapphire, rigid clear polymers, or other materials that are optically clear. In other embodiments, the glass layer  110  may include exterior coatings that improve oleophobicity, hydrophobicity, glare resistance, privacy films, etc. to enhance or add properties of material. Structures such a polarization gratings or louvers may also be present. 
     The glass layer  110  may be curved to conform to a curve of the display  11  if a curve is present. It is preferred that the glass  110  is curved by heat bending. 
     The screen protector may include a layer of optically clear adhesive  115  disposed on the underside or inward facing surface  112  of the glass layer  110 . In the most preferred embodiment, the optically clear adhesive  115  is Kawin KN6050, but other adhesives may be used if they are optically clear. In the most preferred embodiment, the optically clear adhesive  115  is 0.05 mm thick, although the thickness may vary. 
     The optically clear adhesive  115  is generally coextensive with the underlying TPU layer  120 . However, in some embodiments, the optically clear adhesive  115  may be applied only to select portions of the inward facing surface  112  of the glass layer  110 , or to select portion of the TPU layer  120 . The optically clear adhesive  115  adheres the TPU layer  120  to the inward facing surface  112  of the glass layer. One skilled in the art will recognize that the TPU layer may be made of some plastic or polymer material other than TPU that have a low durometer when compared to the glass layer  110  or include a flexible elastomer. 
     In some embodiments, the TPU layer  120  may be formed on the glass layer  110  without the need for an adhesive. Similarly, the UV printed layer  140  may be printed directly on the TPU layer. 
     In some embodiments of the invention, the screen protector  100  includes a layer that will contain or adhere the glass fragments of the display  11  or the glass layer  110 . The layer is referred to as an anti-explosion adhesive  130 . The anti-explosion adhesive  130  is preferably 0.075 mm thick, but the thickness can vary. The anti-explosion adhesive  130  is preferably coextensive with the glass layer  110  or the display  11 . In some embodiments, the anti-explosion adhesive may be used in any place that an optically clear adhesive is needed. 
     In some embodiments, the lower surface  132  of the anti-explosion adhesive  130  does not have an adhesive property, so that it does not stick to the layer below it. This does not prevent the adherence of a UV printing layer  140 . 
     In some embodiments of the invention, a UV printing layer  140  is printed on the anti-explosion adhesive  130 . The UV printing layer may be composed of a field of dots or other structures to act as spacers to maintain a slight gap between the lower surface  132  of the anti-explosion adhesive layer  130  and the display  11 . In the most preferred embodiment, the spacers are a field of rigid hemispherical dots. 
     The UV printing layer  140  is preferably coextensive with the anti-explosion adhesive layer  130 , but need not be. The UV printing layer  140  is approximately 0.1 mm thick, but the thickness may vary. The purpose of the UV printing layer is to prevent or diminish Newton Rings or other optical distortions that may be created by two films in close proximity. In the most preferred embodiment, the UV printing layer  140  is formed with Kunyutong UV110. In some embodiments, the UV printing layer  140  includes 0.05 mm dots with 1 mm spacing between the dots. Other dots and variations of the field spacing may be used. 
     In some embodiments of the invention, the UV printing layer  140  is not printed at all, but is sprayed or dipped. 
     In some embodiments, the UV printing layer  140  is also known as an anti-newton ring layer  135 . 
     In some embodiments a double-sided adhesive layer  150  that is optically clear is used to attach the screen protector  100  including any of the previously described layers to the display  11 . The adhesive layer  150  is preferably 0.1 mm thick, but the thickness may vary. In the most preferred embodiment, the temporary adhesive layer is preferably temporary on the side that adheres to the display  11  so that the screen protector  100  can be removed. In the most preferred embodiment, the temporary adhesive layer is Julidatong DT011. Other adhesives such as Fancy FSA-842BD-3-A may be used. 
     The double-sided adhesive layer  150  is preferably applied to the perimeter of the screen protector  100  lamination. The double-sided adhesive layer  150  need not cover the central portion of the lamination. In an embodiment where the UV printing layer  140  or other spacing structure is omitted, it is preferable to have the double-sided adhesive layer is coextensive with the layer above it, such as the anti-explosion adhesive  130 . 
     In some embodiments, a release liner  160  is placed on the double-sided adhesive layer to prevent the adhesive form sticking to objects prior to the installation of the screen protector  100  onto a device with a display  11 . 
     One skilled in the art will recognize that the layers described herein may be laid-up in different combinations. It is also noted that the figures show materials for illustrative purposes and the folding back of a material, such as a glass layer, does not necessarily imply the material will bend or flex to the degree illustrated. 
     The foregoing disclosure of specific embodiments is intended to be illustrative of the broad concepts comprehended by the invention.