Patent Publication Number: US-2019196065-A1

Title: Anti-reflective lens and method for manufacturing the same

Description:
FIELD 
     The subject matter herein generally relates to an anti-reflective lens and a method for manufacturing the anti-reflective lens. 
     BACKGROUND 
     Optical products such as spectacle lenses can be strongly reflective. But ghosting and flaring can occur, failing to give clear visibility. To prevent such reflection, anti-reflection films should be generally formed on the spectacle lenses. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Implementations of the present technology will now be described, by way of example only, with reference to the attached figures. 
         FIG. 1  is a diagrammatic view of an exemplary embodiment of an anti-reflective lens. 
         FIG. 2  is a cross-sectional view of the anti-reflective lens taken along II-II line of  FIG. 1 . 
         FIG. 3  is a flowchart of an exemplary embodiment of a method for making an anti-reflective lens. 
         FIG. 4  is a cross-sectional view of a mold used to make the anti-reflective lens of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the embodiments described herein. The drawings are not necessarily to scale, and the proportions of certain parts may be exaggerated to illustrate details and features of the present disclosure better. The disclosure is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings, in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean “at least one.” 
     The term “comprising” when utilized, means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in the so-described combination, group, series, and the like. 
       FIG. 1  illustrates a first exemplary embodiment of an anti-reflective lens  1 . The anti-reflective lens  1  comprises a lens substrate  10  and an anti-reflective layer  30  coated on at least one surface of the lens substrate  10 . 
     The lens substrate  10  comprises an inner surface  11 , an outer surface  13  facing away from the inner surface  11 , and a sidewall  15  connected between the inner surface  11  and the outer surface  13 . 
     The lens substrate  10  may be made of glass, polycarbonate, polymethyl methacrylate, or other transparent materials used to make lenses. 
     Referring to  FIG. 2 , the anti-reflective layer  30  comprises a plurality of nano-structures  33 . The nano-structures  33  are spaced from each other. Each nano-structure  33  protrudes from at least one surface of the lens substrate  10 , to cause the nano-structures  33  to form a compound-eye array. Each nano-structure  33  can be a conical structure or a hemispherical structure. 
     In at least one exemplary embodiment, each nano-structure  33  has a width on the surface of the lens substrate  10  (labeled as “A 1 ”) of about 35 nm to about 555 nm, and a highest point of each nano-structure  33  has a height (labeled as “H 1 ”) of about 40 nm to about 550 nm. A distance between the highest points of two adjacent nano-structures  33  (labeled as “D 1 ”) is about 36 nm to about 650 nm. 
     In at least one exemplary embodiment, the nano-structures  33  are formed on the whole of outer surface  13 . In another exemplary embodiment, the nano-structures  33  may be formed on a part of the outer surface  13 . Also, the nano-structures  33  may be formed on the whole of inner surface  11  or a part of the inner surface  11 . 
     The nano-structures  33  are made by curing a sol-gel material. 
       FIG. 3  illustrates a flowchart of an embodiment of a method for manufacturing an anti-reflective lens  1  in accordance with an exemplary embodiment. The exemplary method is provided by way of example, as there are a variety of ways to carry out the method. Each block shown in  FIG. 3  represents one or more processes, methods, or subroutines, carried out in the exemplary method. Furthermore, the illustrated order of blocks is by example only, and the order of the blocks can change. Additional blocks may be added, or fewer blocks may be utilized, without departing from this disclosure. The exemplary method can begin at block  301 . 
     At block  301 , a sol-gel composition is provided. 
     The sol-gel composition comprises an organic component and an inorganic component. The organic component comprises an organic compound with silane group and an organic compound without silane group. The organic compound with silane group may be at least one of 3-(trimethoxusilyl)propyl methacrylate and methyl-trimethoxysilane. The organic compound without silane group may be at least one of methyl methacrylate and methacrylic acid. The inorganic component may be at least one of SiO2 and TiO2. 
     In at least one exemplary embodiment, the organic compound without silane group has a mass percentage of about 1.5% to about 62% of a total mass of the sol-gel composition. The organic compound without silane group has a mass percentage of about 16.8% to about 80.2% of a total mass of the sol-gel composition. The inorganic component has a mass percentage of about 18% to about 80% of a total mass of the sol-gel composition. 
     At block  302 , referring  FIGS. 1 and 4 , a lens substrate  10  and at least one template  50  are provided. The template  50  comprises a plurality of nano-patterns  51 . The nano-patterns  51  are spaced from each other. The template  50  corresponds to at least one surface of the lens substrate  10 . 
     The lens substrate  10  comprises an inner surface  11 , an outer surface  13  facing away from the inner surface  11 , and a sidewall  15  connected between the inner surface  11  and the outer surface  13 . 
     The lens substrate  10  may be made of glass, polycarbonate, polymethyl methacrylate, or other transparent materials used to make lenses. 
     The template  50  may be made of soft material or rigid material. In at least one exemplary embodiment, the template  50  corresponds to the outer surface  13  of the lens substrate  10 . 
     Each nano-pattern  51  is recessed from a surface of the template  50  facing the lens substrate  10 . Each nano-pattern  51  can be a conical groove or a hemispherical groove. 
     In at least exemplary embodiment, an opening of each nano-pattern  51  has a width (labeled as “A 2 ”) of about 35 nm to about 555 nm, and a lowest point of each nano-pattern  51  has a depth (labeled as “H 2 ”) of about 40 nm to about 550 nm. A distance between the lowest points of two adjacent nano-patterns  51  (labeled as “D 2 ”) is about 36 nm to about 650 nm. 
     At block  303 , the sol-gel composition is coated on at least one surface of the lens substrate  10 , and the template  50  is pressed on the sol-gel composition coated on lens substrate  10 , to cause the sol-gel composition to fully infill the nano-patterns  51 . 
     The sol-gel composition can be coated on the lens substrate  10  by dip coating or spin coating. 
     When the sol-gel composition is to be coated on the lens substrate  10  by dip coating, the lens substrate  10  is immersed in the sol-gel composition and taken out of the sol-gel composition at a rate of about 10 mm/min to about 350 mm/min. When the sol-gel composition is to be coated on the lens substrate  10  by spin coating, a rotation speed for the spin coating is kept between about 800 rpm and 5000 rpm. 
     In at least one exemplary embodiment, the sol-gel composition is coated on the whole of outer surface  13  of the lens substrate  10 , and the template  50  is pressed on the entire outer surface  13 . In another exemplary embodiment, the sol-gel composition is coated on a part of the outer surface  13 . Also, the sol-gel composition may be formed on the whole of inner surface  11  or a part of the inner surface  11 . 
     At block  304 , the sol-gel composition coated on the lens substrate  10  is heated and cured, thereby forming an anti-reflective layer  30 . The anti-reflective layer  30  is combined with the lens substrate  10 . An anti-reflective lens  1  is thus obtained. 
     The anti-reflective layer  30  comprises a plurality of nano-structures  33  corresponding to the nano-patterns  51 . The nano-structures  33  are spaced from each other. The plurality of nano-structure  33  protrudes from at least one surface of the lens substrate  10  to form a compound-eye array. Thereby, an anti-reflective property, a hydrophobic property, an anti-fouling effect, and an abrasion resistance to the anti-reflective lens  1  is achieved. Each nano-structure  33  can be a conical structure or a hemispherical structure. 
     In at least one exemplary embodiment, each nano-structure  33  has a width on the surface of the lens substrate  10  (labeled as “A 1 ”) of about 35 nm to about 555 nm, and a highest point of each nano-structure  33  has a height (labeled as “H 1 ”) of about 40 nm to about 550 nm. A distance between the highest points of two adjacent nano-structures  33  (labeled as “D 1 ”) is about 36 nm to about 650 nm. 
     In at least one exemplary embodiment, the lens substrate  10  with the sol-gel composition and the template  50  is heated to a temperature of about 55 degrees Celsius to about 140 degrees Celsius at a speed of 1° C./min. The final temperature is maintained for about 1 hour to about 12 hours. The sol-gel composition is thereby cured to form the anti-reflective layer  30 , and the anti-reflective layer  30  is combined with the lens substrate  10 . 
     At block  305 , the template  50  is removed. 
     In another exemplary embodiment, the block  301  and the block  302  can be reversed in order. 
     Depending on the embodiment, certain of the steps of methods described may be removed, others may be added, and the sequence of steps may be altered. It is also to be understood that the description and the claims drawn to a method may include some indication in reference to certain steps. However, the indication used is only to be viewed for identification purposes and not as a suggestion as to an order for the steps. 
     It is to be understood, even though information and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the present embodiments, the disclosure is illustrative only; changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the present embodiments to the full extent indicated by the plain meaning of the terms in which the appended claims are expressed.