Patent Publication Number: US-2011075022-A1

Title: Imaging device, electronic apparatus including the same, and method of manufacturing imaging device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2009-214986, filed on Sep. 16, 2009, the entire contents of which are incorporated herein by reference. 
     FIELD 
     The present invention relates to an imaging device, an electronic apparatus including the same, and a method of manufacturing an imaging device. 
     BACKGROUND 
     Electronic apparatuses including imaging devices are known. For example, Japanese Laid-open Patent Publications No. 2003-274234 and No. 2004-40365 each disclose a mobile apparatus including an imaging device. 
     An imaging device may include an imaging unit and a transparent panel facing the imaging unit. By providing a pattern on the panel, the decorativeness of the imaging device is improved. In some cases, anti-reflection (AR) coating is provided on a surface of the panel near the imaging unit. A possible method of forming a pattern on the AR-coated surface includes applying resin to the AR-coated surface, forming a pattern on the resin, and hardening the resin. However, the adhesion between the AR-coated surface and resin is not good. Therefore, in some cases, a resin layer may not successively be provided on the AR-coated surface. 
     SUMMARY 
     An imaging device includes an imaging unit, and a panel facing the imaging unit. The panel includes a panel body that has an anti-reflection-coated surface treated with anti-reflection coating and has a portion thereof overlapping an angle of view of the imaging unit, a sheet that is provided on a portion of the anti-reflection-coated surface outside of the angle of view, and a resin layer that has a pattern and is provided on a side of the sheet near the imaging unit. 
     The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A and 1B  illustrates a mobile phone according to an embodiment; 
         FIG. 2A  is an exploded perspective view of the mobile phone; 
         FIG. 2B  is an enlarged view of a part including a panel; 
         FIG. 3  is a cross-sectional view taken along line A-A in  FIG. 2B ; 
         FIGS. 4A ,  4 B,  4 C, and  4 D illustrates a method of manufacturing an imaging device; and 
         FIG. 5  illustrates a method of manufacturing a panel different from the panel according to the embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     A mobile phone, which is an example of an electronic apparatus, is described below. 
       FIGS. 1A and 1B  illustrate a mobile phone according to an embodiment. The mobile phone  1  includes casings  10  and  20 . The casings  10  and  20  include hinge sections  10   h  and  20   h , respectively, and are rotatably connected to each other with the hinge sections  10   h  and  20   h . Thus, the casings  10  and  20  are openably/closably connected to each other. The casings  10  and  20  house electronic components and a printed circuit board. The casing  10  includes a front panel  10 F and a rear panel  10 R. The casing  20  includes a front panel  20 F and a rear panel  20 R. The front panel  10 F is provided with a plurality of operation keys  12  for operating the mobile phone  1 . The front panel  20 F is provided with a display  20 D. Referring to  FIG. 1B , the rear panel  10 R is provided with a panel  50 . 
       FIG. 2A  is an exploded perspective view of the mobile phone  1 .  FIG. 2A  illustrates the mobile phone  1  in a closed state with the casing  10  disassembled. The casing  10  houses an imaging unit  35 . The imaging unit  35  includes a lens barrel made of synthetic resin and an imaging device housed in the lens barrel and configured to receive light from an object to be imaged. The casing  10  has in the outer surface thereof a recess  14  to which the panel  50  is fitted. The casing  10  also has an opening  15  allowing light to pass therethrough to reach the imaging unit  35 . 
       FIG. 2B  is an enlarged view of a part including the panel  50 . The panel  50  has a pattern including a plurality of circles concentric with respect to a specific position. The pattern is provided on the outside of the angle of view of the imaging unit  35 . 
       FIG. 3  is a cross-sectional view taken along line A-A in  FIG. 2B . Referring to  FIG. 3 , the imaging unit  35  is held in the casing  10 . The imaging unit  35  is electrically connected to a printed circuit board  39 , held in the casing  10 , with a flexible substrate  38  interposed therebetween. 
       FIGS. 4A ,  4 B,  4 C, and  4 D illustrate a method of manufacturing an imaging device. Referring to  FIG. 4A , a resin layer  56  is formed on one surface of a sheet  54 . The resin layer  56  is formed by applying pre-hardened resin to the one surface of the sheet  54  with a dispenser or the like. The sheet  54  is made of polyethylene terephthalate (PET), for example. The sheet  54  is optically transparent. A piece of double-sided adhesive tape  55  is provided on the surface of the sheet  54  opposite the surface of the sheet  54  on which resin layer  56  is provided. The piece of double-sided adhesive tape  55  may be substituted by an adhesive agent. 
     A die  60  is intended for forming a pattern on the resin layer  56 . The die  60  has a recess  65  and a transfer portion  63  around the recess  65 . For example, the recess  65  may be in the center of the die  60 . The transfer portion  63  is intended for pattern transfer onto the resin layer  56 . The pattern may include a plurality of circles concentric with respect to the recess  65 , for example. The transfer portion  63  is pressed against the resin layer  56  before the resin layer  56  is hardened, whereby the pattern of the transfer portion  63  is transferred to the resin layer  56 . After the transfer, the resin layer  56  is hardened. For example, ultraviolet rays may be applied to harden the resin layer  56 . 
     Referring to  FIG. 4B , an opening  54   h  is provided in a portion of the resin layer  56  not having the pattern by punching or the like. 
     Referring to  FIG. 4C , the surface of the sheet  54  having the piece of double-sided adhesive tape  55  is made to adhere to an AR-coated surface  52  of a panel body  51 . Thus, the panel  50  having the pattern shown in  FIG. 4D  is obtained. The panel body  51  is made of synthetic resin. The AR-coated surface  52  faces the imaging unit  35 . The AR-coated surface  52  has been treated with AR coating intended for prevention of reflection. The panel  50  is bonded to the recess  14  of the rear panel  10 R with an adhesive or the like. The rear panel  10 R and the front panel  10 F are assembled together. Thus, the panel  50  is positioned in such a manner as to face the imaging unit  35 . 
     Referring to  FIGS. 4C and 4D , the panel  50  includes the panel body  51 , the sheet  54 , the piece of double-sided adhesive tape  55 , and the resin layer  56 . The panel body  51  has the AR-coated surface  52  facing the imaging unit  35  and an opposite surface  53  facing the object to be imaged. The panel body  51  has a portion thereof overlapping the angle of view of the imaging unit  35 . The sheet  54  is provided on a portion of the AR-coated surface  52  on the outside of the angle of view. The resin layer  56  is provided on the side of the sheet  54  near the imaging unit  35  and has the pattern transferred thereto. When the panel body  51  is processed, the panel body  51  is held, with a jig or the like, at a portion thereof on which the sheet  54  is not to be provided. 
       FIG. 5  illustrates a method of manufacturing a panel different from the panel according to the embodiment. In a case illustrated in  FIG. 5 , resin is applied to the AR-coated surface  52  of a panel  50   x , a pattern on the die  60  is transferred onto the resin layer  56 , and the resin layer  56  is hardened. Since the AR-coated surface  52  is treated with AR coating, the resin layer  56  that has been hardened may peel off the AR-coated surface  52 . Such poor adhesion between the AR-coated surface  52  and the resin layer  56  is at least partly because of the following reason. In AR coating, an object is coated with a thin film of metal. The thin film, deposited on the AR-coated surface  52 , is metal. The molecular structures of resin and metal greatly differ from each other. Therefore, the adhesion between resin and metal is poor. In the case shown in  FIG. 5 , since the resin layer  56  has a portion thereof overlapping the angle of view, the image quality may be affected. 
     In the method according to the embodiment shown in  FIGS. 4A to 4D , however, the resin layer  56  is provided on one surface of the sheet  54 , a pattern is formed on the resin layer  56 , and the opposite surface of the sheet  54  is made to adhere to the AR-coated surface  52  of the panel  50 . In this method, since the resin layer  56  is not directly provided on the AR-coated surface  52  of the panel  50 , there is little possibility that the resin layer  56  that has been hardened peels off the sheet  54 . Thus, the resin layer  56  having a pattern is provided on the side of the panel body  51  having the AR-coated surface  52 . 
     The opening  54   h  prevents the sheet  54  from overlapping the angle of view of the imaging unit  35 . That is, the sheet  54 , the piece of double-sided adhesive tape  55 , and the resin layer  56  are provided outside of the angle of view of the imaging unit  35 . Therefore, deterioration of image quality of the imaging unit  35  due to the presences of the sheet  54 , the piece of double-sided adhesive tape  55 , and the resin layer  56  is prevented. 
     The sheet  54 , the piece of double-sided adhesive tape  55 , and the resin layer  56  are provided on the surface of the panel body  51  near the imaging unit  35 . In other words, the sheet  54  and the other foregoing elements are provided on the inner surface of the panel body  51 . That is, the sheet  54  and the other elements are housed in the casing  10 , thereby being prevented from peeling off the panel body  51 . 
     While a specific embodiment of the present invention has been described above, the present invention is not limited to such a specific embodiment, and various changes and modifications may be made to the embodiment within the scope of the present invention defined in the appended claims. 
     The electronic apparatus is not limited to mobile phones. For example, the electronic apparatus may be a personal digital assistant (PDA) or a notebook personal computer. The electronic apparatus may be either a mobile apparatus or a desktop apparatus. 
     It is also acceptable that, after the resin layer  56  having a pattern is provided on one surface of the sheet  54  and the opening  54   h  is provided, a piece of double-sided adhesive tape  55  is provided on the opposite surface of the sheet  54 . 
     According to the embodiment, there are provided an imaging device in which a resin layer having a pattern is provided on the side of a panel body having an AR-coated surface, an electronic apparatus including the same, and a method of manufacturing an imaging device enabling a resin layer having a pattern to be provided on the side of a panel body having an AR-coated surface. 
     All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the principles of the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiment of the present invention has been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.