Abstract:
A lens cover is slidably mounted to a lens, the lens cover comprises a main body, two guiding plated. The two guiding plates respectively protrude outwardly from two opposite side of the main body. Each guiding plate has a plurality of contacting portions. Each guiding plate has a plurality of contacting portions protruding from an surface thereof facing the lens, and each contacting portion includes a rolling ball mounted thereon.

Description:
[0001]    This application is related to co-pending U.S. Patent Applications (Attorney Docket No. US23726), entitled “LENS COVER AND PORTABLE ELECTRONIC DEVICE USING THE SAME”, by Bo Zhang et al. Such applications have the same assignee as the present application and have been concurrently filed herewith. The above-identified applications are incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The exemplary disclosure generally relates to lens covers, and particularly to lens covers used in portable electronic devices. 
         [0004]    2. Description of Related Art 
         [0005]    It is now common to find digital camera modules incorporated into many types of portable electronic devices. Such portable electronic devices tend to incorporate digital camera modules of increasing quality and functionality as various manufacturers compete with each other to provide improved funtionalities while maintaining portability of the device. 
         [0006]    Typically, as the quality of the camera assembly increases, the requirement for larger size and higher quality lenses increases. Larger lenses allow more light into the camera assembly, thereby improving image quality. To maintain the quality of the images, some kind of lens cover is slidably mounted on the lens, in order to protect the lens from scratches and containments. However, the friction factor between the lens and the lens cover is so large that the lens cover cannot slide smoothly relative to the lens. 
         [0007]    Therefore, there is room for improvement within the art. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    Many aspects of the exemplary embodiments can be better understood with references to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the exemplary lens cover and portable electronic device using lens cover. Moreover, in the drawings like reference numerals designate corresponding parts throughout the several views. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like elements of an exemplary embodiment. 
           [0009]      FIG. 1  is an exploded view of one exemplary embodiment of a lens cover used in a portable electronic device, the portable electronic device including a housing, a rear cover, a lens and a lens cover. 
           [0010]      FIG. 2  is similar to the  FIG. 1 , but showing the portable electronic device in another aspect. 
           [0011]      FIG. 3  is a partially enlarged and assembled view of the portable electronic device in an opened state. 
           [0012]      FIG. 4  is similar to the  FIG. 3 , but the lens cover is in a closed state. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    Referring to  FIGS. 1 and 2 , an exemplary embodiment of a lens cover  40  can be used on a portable electronic device  100 , such as a cellular phone or any electronic device where a lens is desirable. The portable electronic device  100  includes a housing  10 , a rear cover  20 , a lens  30 , a lens cover  40 , a plurality of rolling balls  80  and an elastic element  50 . The rear cover  20  is attached to the housing  10  to form an enclosure  60  (seen  FIG. 3 ) for accommodating the lens  30  and the lens cover  40 . The lens  30  is mounted to the housing  10  to protect digital camera (not shown) in the portable electronic device  100 . The lens cover  40  is slidably mounted between the lens  30  and the rear cover  20  so that the lens cover  40  can cover or expose the digital camera selectively. The elastic element  50  connects the lens cover  40  to the lens  30  to provide an elastic force for driving the lens cover  40  slid. The rolling balls are mounted between the lens cover  40  and the lens to decrease friction force between the lens  30  and the lens cover  40 . 
         [0014]    The housing  10  includes a mounting portion  12 . The mounting portion  12  includes a flat plate  121 , a camera hole  125 , a passage  127  and a plurality of retaining holes  1213 . The passage  127  is longitudinally defined through the flat plate  121 . The camera hole  125  are also defined through the flat plate  121  adjacent to the passage  127 . The camera hole  125  may accommodate a camera (not shown) of the portable electronic device  100  therein. The retaining holes  1213  are defined in the flat plate  121  surrounding the camera hole  125  and the passage  127 . The retaining holes  1213  are configured to mate with the rear cover  20 . 
         [0015]    The lens  30  may be made of glassy material or transparent plastic material. The lens  30  has a latching portion in the form of a trough  31  defined therethrough. The trough  31  is configured to latching one end of the elastic element  50  therein. The lens  30  further includes a notch  32  defined therethrough for mating with the lens cover  40 . 
         [0016]    The lens cover  40  includes a main body  41  substantially having the same shape as the camera hole  125  with a larger size than the camera hole  125 . Each side of main body  41  has at least one guiding plates  43  protruding therefrom. The guiding plates  43  are slidably mounted to a guiding groove in the form of a slit  70  (seen  FIG. 3 ) defined between the lens  30  and the rear cover  20 , so that the main body  41  of lens cover  40  can slide relative to the lens  30  to cover or expose the camera hole  125 . When the lens cover  40  is closed as shown in  FIG. 4 , the lens  30  aligned with the camera hole  125  is completely covered by the main body  41 , so that it is possible to prevent a stain from sticking to the lens  30  where is aligned with the camera hole  125 . 
         [0017]    The lens cover  40  further includes a plurality of contacting portions  432 , a trigger  45 , a projection  412  and a finger grip portion  414 . Each contacting portion  432  is a block protruding from a bottom surface of the guiding plates  43  facing the lens  30 . Each contacting portion  432  has an installing hole  4322  defined therein. The installing holes  4322  have the same shape and size as the rolling balls  80  for rotatably accommodating the rolling balls  80 . The function of rolling balls  80  in the contacting portions  432  is as follows: when the lens cover  40  is mounted on the lens  30 , the lens  30  can contact with the rolling balls  80  in the contacting portions  432  to prevent the bottom surface of the lens cover  40  from directly contacting the lens  30 , so as to decrease the frictional area between the lens  30  and the lens cover  40  and reduce the potential for scratching the lens from that of conventional designs. Additionally, when the lens cover  40  slides relative to the lens  30 , the rolling balls  80  will be rolled. Thus, friction force between the lens  30  and the lens cover  40  is decreased so as to facilitate moving the lens cover  40  relative to the lens  30 . 
         [0018]    The trigger  45  in the form of a rectangular plate protrudes from a distal end of one guiding plate  43  on the lens cover  40 . The trigger  45  is slidably accommodated in the passage  127  and partially inserted into the housing  10 . When the lens cover  40  slides relative to the lens  30 , the trigger  45  slides with the lens cover  40  to activate a switch (not shown) that turns on the digital camera(not shown). The projection  412  is a pole protruding from a surface of the main body  41  facing the lens  30 . The projection  412  is configured to engage with the elastic element  50 . The finger grip portion  414  is a rib transversely protruding from another surface of the main body  41  opposite to the projection  412 . The finger grip portion  414  facilitates sliding the lens cover  40  relative to the lens  30 . 
         [0019]    The rear cover  20  includes a bottom panel  19  and a peripheral panel  22  protruding from an edge of the bottom panel  19 . The rear cover  20  has a window  23  defined through the bottom panel  19 . The window  23  corresponds to the camera hole  125  and is configured to accommodate the lens cover  40 . The window  23  is defined by a first inner surface  231 , a second inner surface  232  opposite the first inner surface  231 , and two opposite third inner surfaces  233  connecting the first inner surface  231  with the second inner surface  232 . A length between the first inner surface  231  and the second inner surface  232  meets the length of the sliding distance of the lens cover  40 . A width between the third inner surfaces  233  meets the width of the main body  41  of the lens cover  40 . Thus, the main body  41  can slide in the window  322  steadily. The rear cover  20  further has a plurality of retaining poles  25  protruding from a distal end portion of the peripheral panel  22 . The retaining poles  25  are retained in the retaining holes  1213  to assemble the rear cover  20  to the housing  10 . 
         [0020]    The elastic element  50  is mounted between the lens cover  40  and the lens  30 , to provide an elastic force for driving the lens cover  40  slid. In this exemplary embodiment, the elastic element  50  is a coil spring including a ring-shaped portion  51  formed one end thereof and a hook  53  formed another end thereof. The elastic element  50  is mounted to the lens cover  40  in such a manner that the ring-shaped portion  51  of the elastic element  50  is inserted into the projection  412  of the lens cover  40 . The elastic element  50  is mounted to the lens  30  in such a manner that the hook  53  of the elastic element  50  is inserted to the trough  31  of the lens  30 . 
         [0021]    Referring to  FIGS. 1 to 3 , during assembling the portable electronic device  100 , firstly, the lens  30  is attached to the flat plate  121  to cover the camera hole  125 . Secondly, the ring-shaped portion  51  of the elastic element  50  is wound to the projection  412  of the lens cover  40 , so that one end of the elastic element  50  is mounted to the lens cover  40 . Then, the trigger  45  of the lens cover  40  is accommodated in the passage  127  through the flat plate  121 , the hook  53  of the elastic element  50  is inserted to the trough  31  of the lens  30 , so as to mount the lens cover  40  on the lens  30 . At this time, the rolling balls  80  are mounted on the lens  30  to support the lens cover  40  to the lens  30 , and the lens cover  40  covers the camera hole  125  of the housing  10 . After that, the retaining poles  25  of the rear cover  20  are secured into the retaining holes  1213  of the housing  10  so that the rear cover  20  is assembled to the housing  10 . At this time, the guiding plates  43  of the lens cover  40  are slidably mounted to the slit  70  defined between the lens  30  and the rear cover  20 , and the first inner surface  231  of the window  23  slightly biases the lens cover  40  so the elastic element  50  is slightly distorted to accumulate rebounding elastic force. Thereby, the lens cover  40  is firmly accommodated in the window  23 . 
         [0022]    Referring to  FIG. 4 , in use, the finger grip portion  414  is pushed toward the second inner surface  232  of the window  23 , to drive the guiding plate  43  of the lens cover  40  moved on the lens  30  toward the second inner surface  232 , and the rolling balls are rolled to decrease friction force between the guiding plate  43  and the lens  30 . At this time, the ring-shaped portion  51  of the elastic element  50  also moves toward the second inner surface  232  so that the elastic element  50  is distorted to accumulate elastic force. When the ring-shaped portion  51  is aligned with the hook  53 , the elastic element  50  is mostly distorted to accumulate maximum of the elastic force, i.e., the lens cover  40  is in an intermediate state. The finger grip portion  414  is continuously push toward the second inner surface  232  until the ring-shaped portion  51  is over the intermediate state, the elastic element  50  will expand under previously accumulated elastic force, which drives the lens cover  40  continuously moving to the second inner surface  232 . At this stage, the trigger  45  activates a switch (not shown) that turns on the digital camera (not shown), and the camera hole  125  is exposed, so the portable electronic device  100  is ready to take a photo. 
         [0023]    It is to be understood, however, that even though numerous characteristics and advantages of the exemplary disclosure have been set forth in the foregoing description, together with details of the structure and function of the disclosure, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.