Abstract:
A woofer module is used for outputting alow-frequency audio signal, and can be inserted into and removed from anexpansion slot of a portable computer. The woofer module has a housing, a speaker unit positioned inside the housing for generating the audio signal, a predetermined space positioned inside the housing for resonating the audio signal, and a bass reflex duct positioned inside the housing which is connected to an output vent of the predetermined space and an output vent of the housing for transmitting the audio signal from the output vent of the housing to an ambientenvironment.

Description:
BACKGROUND OF INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The invention relates to a woofer module, and more particularly, to a removable woofer module of a portable computer.  
           [0003]    2. Description of the Prior Art  
           [0004]    Recently, multimedia technology becomes so popular that a user can interact with a computer system to efficiently access variety of desired audio data and image data. Therefore, how to make a portable computer providing the user with amazing audio effects has become a key concern for computer manufacturers. Please refer to FIG. 1, which is a diagram of a first prior art portable computer  10 . The portable computer  10  has a housing  12  and a plurality of speakers  14   a ,  14   b ,  14   c . The speakers  14   a ,  14   b  respectively correspond to a left channel and a right channel for generating stereo sound. In addition, the speaker  14   c  is a woofer used to generate low-frequency signals. To make output signals generated by the speaker  14   c  to have lower frequencies, the portable computer  10  has to comprise a cavity for resonating the output signals generated from the speaker  14   c . Only the existing spare space inside the interior of the portable computer  10  can be utilized to install the speaker  14   c  in conjunction with the required resonating cavity. In addition, the speaker  14   c  is fixed in the portable computer  10  at a predetermined location, that is, the speaker  14   c  is not designed to be a removable module. When the speaker is in unused state, the occupied space cannot be freed for other purposes.  
           [0005]    Please refer to FIG. 2 in conjunction with FIG. 3. FIG. 2 is a diagram of a second prior art portable computer  20 . FIG. 3 is a diagram of a power module  26  shown in FIG. 2. The portable computer  20  has a housing  22 , two speakers  23   a ,  23   b , two expansion slots  24   a ,  24   b , a hard-disk drive  25 , and a power module  26  (batteries for example). The expansion slots  24   a ,  25   b  are respectively used to install expansion devices such as the hard-disk drive  25  and the power module  26 . Two speakers  23   a ,  23   b  respectively correspond to a left channel and a right channel for generating stereo sound. The power module  26  is installed in the expansion slot  24   b  and is removable from the expansion slot  24   b . The power module  26  not only provides the portable computer  20  with a predetermined voltage used to power the portable computer  20 , but also provides a function for outputting low-frequency signals. As shown in FIG. 3, the power module  26  includes a battery device  28  and a woofer  30 . The battery device  28  is used to output the predetermined voltage, and the woofer  30  is used to output the low-frequency signal. There is a cavity located inside the housing of the power module  26  for the purpose of resonating the low-frequency signals generated from the woofer  30 . Though the module design of woofer  30  couple with battery device  28  is efficient, but the power capacity provided by the battery device  28  is greatly reduced because of the additional woofer  30  in the power module  26 . In other words, the battery life of the portable computer  20  is shortened due to the reduced power capacity. In addition, the cavity for resonating the signals is too narrow to make the signals have lower frequencies. It is noteworthy that the low-frequency signals outputted from the woofer  30  would generate noticeable vibration. The prior art portable computer  20  does not provide any devices to lessen or isolate the vibrations. When a hard-disk drive or an optical disk drive accesses the data, the data access operation is prone to be influenced by the vibrations causing the access to be corrupted or stopped. In addition, the vibrations make a disturbing noise while the user is using the portable computer.  
         SUMMARY OF INVENTION  
         [0006]    It is therefore a primary objective of the claimed invention to provide a removable woofer module with shock-absorbing ability to solve the above-mentioned problem.  
           [0007]    According to the claimed invention, a portable computer comprises a first housing having an expansion slot and a woofer module installed in the expansion slot for generating a low-frequency signal. The woofer module is removable from the expansion slot, and the woofer module comprises a second housing, a speaker unit positioned in the second housing for generating the low-frequency signal, a predetermined room positioned in the second housing for resonating the low-frequency signal, and a bass reflex duct positioned in the second housing. The bass reflex duct is used to connect an output vent of the predetermined room and an output vent of the second housing so that the low-frequency signal is outputted from the output vent of the second housing.  
           [0008]    The claimed invention not only provides the portable computer with low-frequency signals, but also protects the portable computer from being disturbed by the vibration caused by the low-frequency signals.  
           [0009]    These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0010]    [0010]FIG. 1 is a diagram of a first prior art portable computer.  
         [0011]    [0011]FIG. 2 is a diagram of a second prior art portable computer. FIG. 3 is a diagram of a power module shown in FIG. 2.  
         [0012]    [0012]FIG. 4 is an exploded view of a first embodiment of a woofer module according to the present invention.  
         [0013]    [0013]FIG. 5 is a top view of the woofer module shown in FIG. 4.  
         [0014]    [0014]FIG. 6 is a bottom view of the woofer module shown in FIG. 4.  
         [0015]    [0015]FIG. 7 is an exploded view of a second embodiment of a woofer module according to the present invention.  
         [0016]    [0016]FIG. 8 is a top view of a woofer module shown in FIG. 7.  
         [0017]    [0017]FIG. 9 is a bottom view of the woofer module shown in FIG. 7. 
     
    
     DETAILED DESCRIPTION  
       [0018]    Please refer to FIG. 4, FIG. 5, and FIG. 6 in conjunction with FIG. 2. FIG. 4 is an exploded view of a first embodiment of a woofer module according to the present invention. FIG. 5 is a top view of the woofer module  40  shown in FIG. 4. FIG. 6 is a bottom view of the woofer module  40  shown in FIG. 4. The woofer module  40  has a housing  42 , a speaker unit  44 , and a bass reflex duct  46 . The housing  42  has a top cover  42   a  and a bottom cover  42   b , and a cavity is formed inside the housing  42 . When the speaker unit  44  generates a low-frequency signal, the low-frequency signal resonates in the predetermined cavity  48  between the speaker unit  44  and the bass reflex duct  46 . An air pressure surge is induced from the low-frequency signal to push the air inside the woofer module  40  and generates airflow so that the airflow enters the bass reflex duct  46  via an output vent  50  of the predetermined cavity  48 . In the end, the airflow is outputted from the woofer module  40  thru the output vent  52 . Based on the prior art of bass reflex principle, the low frequency extension of the woofer module  40  can be increased via bass reflex duct  46 . In addition, the woofer module  40  is installed onto a chassis  54 . The size of the chassis  54  corresponds to that of the expansion slot  24   a  or  24   b  shown in FIG. 2. The woofer module  40  installed on the chassis  54  is inserted into the expansion slot  24   a  or  24   b  so that the woofer module  40  is electrically connected to the portable computer  20 . As mentioned before, the vibrations and noise occur when the speaker unit  44  generates the low-frequency signals. If the vibrations are transferred to the portable computer  20 , some internal devices may not operate properly. The present embodiment, therefore, uses rubber rings  56   a ,  56   b  or other shock-absorbing materials to prevent the vibrations, which are generated from the woofer module  40 , from being transferred to the chassis  54 . Because the chassis  54  and the expansion slot  24   a  or  24   b  are connected and fixed through a screw  58  and a corresponding hole  59 , if the vibrations generated from the woofer module  40  transmit to the chassis  54 , the vibrations are further transmitted to the whole portable computer  20  through the screw  58  and the corresponding hole  59 . Therefore, when a screw  60  fastens the woofer module  40  and the chassis  54  together via a corresponding hole  61 , two enclosed rubber rings  56   a ,  56   b  are used to absorb vibrations generated from the woofer module  40 . The disturbance caused by the vibrations is filtered out by the rubber rings  56   a ,  56   b  without affecting the chassis  54 . In addition, the bass reflect duct  46  has a connector  62  compatible to the interface of expansion slot  24   a  or  24   b . For example, the portable computer  20  provides the speaker unit  44  with an appropriate voltage via a PCMCIA interface.  
         [0019]    Please refer to FIG. 7, FIG. 8, and FIG. 9. FIG. 7 is an exploded view of a second embodiment of a woofer module according to the present invention. FIG. 8 is a top view of a woofer module  70  shown in FIG. 7. FIG. 9 is a bottom view of the woofer module  70  shown in FIG. 7. The woofer module  70  has a housing  72 , a speaker unit  74 , and a bass reflect duct  76 . The housing  72  has a top cover  72   a  and a bottom cover  72   b , and a cavity is formed inside the housing  72 . A screw  73  is used to fasten the top cover  72   a  and the bottom cover  72   b . When the speaker unit  74  generates the low-frequency signals, the low-frequency signals resonate in a predetermined cavity  78  between the speaker unit  74  and the bass reflect conduct  76 . An air pressure surge is induced from the low-frequency signal to push the air inside the woofer module  70  and generates airflow so that the airflow enters the bass reflex duct  76  via an output vent  79  of the predetermined cavity  78 . In the end, the airflow is outputted from the woofer module  70  thru the output vent  80 . Based on the bass reflex principle, the low frequency extension of the woofer module  70  can be increased via bass reflex duct  76 . In addition, the woofer module  70  has a connector  82  compatible to the interface of expansion slot  24   a  or  24   b . The portable computer  20 , therefore, provides the speaker unit  74  with an appropriate voltage via the interface. As mentioned before, the chassis  54  and the expansion slot  24   a  or  24   b  are connected and fastened through a screw  58  and a corresponding hole  59 . In the present embodiment, the woofer module  70  is not installed onto a chassis  54  as shown in FIG. 4. In order to make the screw  84 , which pierces housing of the portable computer  20 , fasten the corresponding hole  86  located at the bottom cover  72   b  successfully, the housing  72  has a protruded portion  88  positioned under the bass reflect duct  76 , and the hole  86  is positioned on the protruded portion  88 . The screw  84 , therefore, is capable of fastening the woofer module  70  and the corresponding expansion slot  24   a  or  24   b  with the help of the protruded portion  88 . In other words, the protruded portion  88  takes the place of the chassis  54  shown in FIG. 4 to contact the expansion slot  24   a  or  24   b  so that the screw  84  works normally without the chassis  54 . Please note that the housing  72 , in the preferred embodiment, has a narrow portion corresponding a location where the bass reflect duct  76  is connected to the output vent  79  of the predetermined cavity  78 . It is obvious that the predetermined cavity  78  and the bass reflect ducts  76  are connected through part of the housing  72  surrounding the output vent  79 . Because a cross-section area of the narrow portion is inevitably small, and has a great flexibility accordingly, the vibrations generated from the speaker unit  74  are alleviated. As mentioned above, the hole  86  is positioned on the protruded portion  88 , and the protruded portion  88  is located under the bass reflect duct  76 . When the bass reflect duct  76  alleviates vibrations from the speaker unit  74 , the shocks, which pass through the screw  84  and the corresponding hole  86 , are simultaneously alleviated without disturbing the whole portable computer  20 .  
         [0020]    In contrast to the prior art, the claimed invention provides a removable woofer module that is compatible with an expansion slot positioned in a portable computer. The woofer module has a bass reflect duct used to increase the low frequency extension of the woofer module. In addition, the first embodiment of the claimed woofer module discloses a shock-absorbing apparatus such as a rubber ring for alleviating the vibrations transmitted to the expansion slot. The portable computer is protected against the shocks. As a result, the portable computer works properly. The second embodiment of the claimed woofer module discloses a flexible and narrow portion connecting the bass reflect duct and a resonance cavity so that the shocks are alleviated without affecting operation of the portable computer. To sum up, the claimed invention not only provides the portable computer with low-frequency signals, but also protects the portable computer from being disturbed by the vibrancies induced by the low-frequency signals. The claimed woofer module is capable of sharing the same expansion slot with other removable modules such as a floppy disk drive or a secondary hard-disk drive so that the utilization of limited spare space in the portable computer is more flexible.  
         [0021]    Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.