Abstract:
An optical module ( 100 ) includes a lens barrel ( 10 ), a lens module ( 20 ), a filter ( 40 ) and a clip ( 50 ). The lens barrel defines a groove in an inner periphery thereof. The lens module is received in the lens barrel. The clip is received in the groove of the lens barrel, so as to fix the lens module in the lens barrel. The filter is received in the lens barrel, between the lens module and the clip.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This application is a continuation application of U.S. Ser. No. 11/437,196, filed May 18, 2006, the contents of which are hereby incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention generally relates to optical modules used in photography and imaging equipment and, more particularly, to an optical module for a digital camera.  
         [0004]     2. Description of Related Art  
         [0005]     Currently, digital camera modules are included as a feature in a wide variety of portable electronic devices and, of course, in stand-alone digital camera units. Most portable electronic devices are becoming progressively more miniaturized over time, and digital camera modules are correspondingly becoming smaller and smaller. Nevertheless, in spite of the small size of a contemporary digital camera module, consumers still demand excellent imaging.  
         [0006]     Optical modules used for digital camera modules typically include a barrel, a lens module, a spacer, and a filter. The lens module and the spacer are received in the barrel. The filter is fixedly mounted in the barrel by using, for example, a glue/adhesive, thereby preventing the lens module and the filter from falling out of the barrel. When the glue/adhesive used to adhere the filter to the barrel is dilute, it can seep into the lens module via capillary action, thus impairing imaging quality of the optical module.  
         [0007]     Therefore, a new optical module is desired in order to overcome the above-described shortcomings.  
       SUMMARY OF THE INVENTION  
       [0008]     In one embodiment thereof, an optical module includes a lens barrel, a lens module, a filter and a clip. The lens barrel defines a groove in an inner periphery thereof. The lens module is received in the lens barrel. The clip is received in the groove of the lens barrel so as to fix the lens module in the lens barrel. The filter is received in the lens barrel and between the lens module and the clip.  
         [0009]     Other novel features will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     Many aspects of the optical module can be better understood with reference 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 present optical module. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.  
         [0011]      FIG. 1  is an exploded, isometric view of an optical module in accordance with a first embodiment;  
         [0012]      FIG. 2  is an enlarged, assembled, isometric view of the optical module shown in  FIG. 1 ;  
         [0013]      FIG. 3  is an enlarged, cross-sectional view taken along line III-III of  FIG. 2 ; and  
         [0014]      FIG. 4  is a schematic, cross-sectional view of an optical module in accordance with a second embodiment. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0015]     Referring to  FIG. 1 , an optical module  100  according to a first embodiment of the present invention includes a lens barrel  10 , a lens module  20 , a spacer  30 , a filter  40 , and a clip  50 . Referring also to  FIG. 2 , the lens module  20 , the spacer  30 , the filter  40 , and the clip  50  are engagingly received in the lens barrel  10  one on top of the other in that order.  
         [0016]     Referring also to  FIG. 3 , the lens barrel  10  is substantially a hollow cylinder, having a partially-closed end and an open end on the opposite end to the partially-closed end. The lens barrel  10  includes a columned ladder-like cavity  101  therein. The cavity  101  has a small diameter cavity  102  adjacent to the partially-closed end, and a large diameter cavity  103  adjacent to the open end. The small diameter cavity  102  is configured for receiving the lens module  20  and the spacer  30 . The large diameter cavity  103  is configured for receiving the filter  40 . An annular groove  104  is defined in a surface of the large diameter cavity  103 , and is configured for receiving the clip  50 .  
         [0017]     The lens module  20  includes at least one lens. In the illustrated embodiment, the lens module  20  includes two lenses  201 . It is to be understood that lenses of any number and type could be used in the lens module  20 .  
         [0018]     The spacer  30  is substantially ring-shaped. The spacer  30  is engagingly received in the small diameter cavity  102  of the lens barrel  10 . The spacer  30  is configured for adjusting a distance between the lens module  20  and other optical elements (for example, the filter  40 ) of the optical module  100 .  
         [0019]     The filter  40  is substantially disk-shaped. The filter  40  is engagingly received in the large diameter cavity  103  of the lens barrel  10 . The filter  40  is used to selectively transmit light having certain properties, while blocking the remainder. The filter  40  can be selected, for example, from a group consisting of infrared-cut filters and low-pass filters.  
         [0020]     The clip  50  is substantially a C-shaped ring, and made of elastic material. The clip  50  has an outer diameter slightly greater than a diameter of the groove  104  of the lens barrel  10 , so that the clip  50  will be in a compressed state when the clip  50  is located in the groove  104  of the lens barrel  10 , and will fix the lens module  20 , the spacer  30 , and the filter  40  in the lens barrel  10 . In alternative embodiments, the clip  50  can be replaced by another fixation element, which can fix the lens module  20 , the spacer  30 , and the filter  40  in the lens barrel  10 .  
         [0021]     In assembly of the optical module  100 , the lens module  20 , the spacer  30 , and the filter  40  are received in the cavity  101  of the lens barrel  10  in that order, and the lens module  20  is adjacent to the partially-closed end of the lens barrel  10 . Then, the clip  50  aligns with the open end of the lens barrel  10 , and an operator exerts a force on the clip  50 , such that the clip  50  is deformed and located in the groove  104 . At this time, the lens module  20 , the spacer  30 , the filter  40 , and the clip  50  are all received in the cavity  101  of the lens barrel  10 . The spacer  30  is located between the lens module  20  and the filter  40 , with the spacer  30  abutting the lens module  20  and the filter  40 . The filter  40  is located between the spacer  30  and the clip  50 , with the filter  40  abutting the spacer  30  and the clip  50 . The clip  50  is in a compressed state, thereby preventing the lens module  20 , the spacer  30 , and the filter  40  from falling out of the lens barrel  10 , and fixing the lens module  20 , the spacer  30 , and the filter  40  in the lens barrel  10 . The optical module  100  is thus completely assembled.  
         [0022]     In the above-described assembly processes, the clip  50  can fix the lens module  20 , the spacer  30 , and the filter  40  in the lens barrel  10 . Therefore, there is no need to use a glue/adhesive, so the lens module  20  will not be polluted by the glue/adhesive. Imaging quality of the optical module  100  can thus be improved.  
         [0023]     Referring to  FIG. 4 , an optical module  200  according to a second embodiment of the present invention is shown. Most of the structure of the optical module  200  of the second embodiment is similar to that of the optical module  100  of the first embodiment, except that a cavity  601  of a lens barrel  60  has a diameter cavity (not labeled). A groove  602  is defined in a surface of the cavity  601  adjacent to an open end of the lens barrel  60 . A diameter of a clip  80  is slightly greater than a diameter of the groove  602 . The clip  80  is in a compressed state when the clip  80  is located in the groove  602  of the lens barrel  60 , thereby preventing a lens module  20 , a spacer  30 , and a filter  70  from falling out of the lens barrel  60 , and fixing the lens module  20 , the spacer  30 , and the filter  70  in the lens barrel  60 .  
         [0024]     In the above-described embodiments, the lens barrels  10 ,  60 , the cavities  101 , 601 , the spacer  30 , the filters  40 ,  70  are all round-shaped. In alternative embodiments, the lens barrels  10 ,  60 , the cavities  101 , 601 , the spacer  30 , and/or the filters  40 ,  70  could be of another suitable shape, for example, arc-shaped.  
         [0025]     In alternative embodiments, the spacer  30  could be omitted. Also, the filters  40 ,  70  could be omitted.  
         [0026]     It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.