Patent Publication Number: US-2013236645-A1

Title: Method for locally forming smooth surface on frosted glass

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates to protective glass for screens of portable electronic devices, and more particularly, to frosted glass that has micro-roughness on its surface for preventing undesirable fingerprint transfer and light reflection and has a local area formed with a smooth surface through which a camera lens can capture images clearly. 
     2. Description of Related Art 
     The display screens, particularly the touch screens of portable electronic devices such as mobile phones, digital cameras, PDAs, tablet computers or notebook computers are typically protected by tempered glass from scratches or over-pressing damages. Considering that tempered glass with a smooth surface can accumulate fingerprints and desirably hinder users&#39; operating the devices by reflecting incident light, some manufacturers frost tempered glass by forming micro-roughness on the surface of the latter, so as to successfully solve the problems about fingerprints and light reflection. Most existing portable electronic devices, however, adopt an integrated structure for protecting the display screen and the camera lens, which is made by covering the display screen and the camera lens with a single piece of frosted glass. In this case, the micro-roughness on the surface of the frosted glass can scatter incident light and hinder the camera lens from taking clear images. 
     A conventional approach to allowing clear images, as shown in  FIG. 1  and  FIG. 2 , involves providing a through hole  2  on the frosted glass  1  so that the through hole  2  is aligned with and allows the camera lens  3  to capture clear image therethrough. However, since the tempered glass is hardened, the difficult work of forming the through hole on the glass can complicate the processing and increase the overall manufacturing costs. Additionally, as such a through hole is usually located near an edge of the glass, poor drilling can even make the glass crack and become defective. 
     SUMMARY OF THE INVENTION 
     According to the present invention, a method for locally forming a smooth surface on frosted glass primarily comprises the following steps: 
     a) preparing a piece of frosted glass; 
     b) locally coating the frosted glass with a sealant; and 
     c) such forming the sealant that has a smooth surface. 
     The primary objective of the present invention is to provide a method that locally forms the smooth surface on the frosted glass, which allows a video camera to capture clear images therethrough, so as to prevent blurred images caused by micro-roughness on a surface of the frosted glass. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention as well as a preferred mode of use, further objectives and advantages thereof will be best understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a perspective view of a conventional portable electronic device; 
         FIG. 2  is a partial, cross-sectional view of the conventional portable electronic device; 
         FIG. 3  is a perspective view of a portable electronic device made using the method of the present invention; 
         FIG. 4A  and  FIG. 4B  are schematic drawings illustrating the method of the present invention; 
         FIG. 4C  is a partial, cross-sectional view of the portable electronic device made using the method of the present invention; 
         FIG. 5  is a flowchart of the method of the present invention; and 
         FIG. 6  is a partial, cross-sectional view of a portable electronic device made using the method according to another embodiment of the present invention; 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 3  through  FIG. 5  illustrate a method for locally forming a smooth surface on frosted glass according to one embodiment of the present invention, which comprising the following steps: 
     a) preparing a piece of frosted glass  10 , wherein the frosted glass  10  is frosted because at least one surface thereof is formed with micro-roughness, as shown in  FIG. 4A ; 
     b) locally coating the frosted glass  10  with a sealant  20 , such that the sealant  20  fill in at least a part of depressed areas of the micro-roughness on the surface of the frosted glass  10 ; and 
     c) such forming the sealant  20  that provides a smooth surface  30  on the frosted glass  10 . 
     Therein, the sealant  20  may be transparent ink, transmitting glue, previous-to-light plastic or glass. For example, in the embodiment where the sealant  20  is transparent ink, the ink may be coated at where the smooth surface  30  is to be formed through printing and dried to provide a smooth surface  30 . 
     As shown in  FIG. 4C , when the frosted glass  10  is assembled to a portable electronic device, the smooth surface  30  is aligned with a camera lens  90 , so that incoming light is allowed to directly pass through the smooth surface  30  and reach the camera lens  90  without being scattered by the micro-roughness of the frosted glass  10 , and the camera lens  90  can take clear images. 
     In an embodiment where the present invention is applied to frosted glass  10  with both sides having micro-roughness, the sealant  20  may be applied to the both sides of the frosted glass  10  so as to form smooth surfaces  30  at the two sides of the frosted glass  10 . In an embodiment where the present invention is applied to frosted glass  10  with only one side having micro-roughness, only the side with the micro-roughness is coated with the sealant  20  and then has the local smooth surface  30 . 
     In other embodiments, the sealant  20  may be realized as plastic or glass in a melted phase, so that when the melt plastic or glass is cooled and cured, the smooth surface  30  is formed on the frosted glass  10 . Therein, the transparent ink, transmitting glue, previous-to-light plastic or glass may be selected to have its light penetration rate and refractive index identical or similar to those of the frosted glass  10 , so as to enhance the effects of locally leveling the micro-roughness on the frosted glass  10  and preventing blurred images, as provided by the present invention. 
     According to the present invention, by simply applying the sealant  20  to the surface of the frosted glass  10  through printing, coating or adhering, a local smooth surface can be provided, so the disclosed method is advantageous for it allows simple processing, low manufacturing costs and a good light-transmission effect. 
     Moreover, for further protecting the smooth surface  30  made of the sealant  20 , the step b) further comprises a step of providing a protection layer  40  over the sealant  20 . This protection layer  40  is configured to secure the sealant  20  from getting damaged or coming off upon application of excessive external forces. The protection layer  40  may be made of transmitting film, previous-to-light plastic or previous-to-light glass. 
     In addition, as shown in  FIG. 6 , the application of the sealant  20  and the formation of the protection layer  40  may be accomplished in a single step. In an embodiment where a transmitting film  50  is used, the transmitting film  50  includes an adhesive layer  51  that can attach the transmitting film  50  to the surface of the frosted glass  10 . The adhesive layer  51  itself may be previous to light, so that the adhesive layer  51  can function as the sealant  20 , and the transmitting film  50  can act as the protection layer  40 . When the transmitting film  50  is attached to the frosted glass  10 , the adhesive layer  51  can level up the micro-roughness thereon and prevent the micro-roughness from causing light scattering. 
     The present invention has been described with reference to the preferred embodiments and it is understood that the embodiments are not intended to limit the scope of the present invention. Moreover, as the contents disclosed herein should be readily understood and can be implemented by a person skilled in the art, all equivalent changes or modifications which do not depart from the concept of the present invention should be encompassed by the appended claims.