Abstract:
The present application discloses a housing for an electronic device ( 1 ), belongs to the technical field of electronic device. Said housing for an electronic device ( 1 ) comprising: a main casing assembly ( 6 ) for accommodating an electronic device ( 1 ) and an end cover assembly ( 7 ) working with the main casing assembly ( 6 ) to seal the main casing assembly ( 6 ); wherein the main casing assembly ( 6 ) comprises a main casing frame ( 8 ), a backplate ( 9 ), and a screen ( 10 ); the end cover assembly ( 7 ) comprises an end cover ( 12 ) and a sealing component ( 13 ) fixedly connected to the end cover ( 12 ). The end cover assembly and the main casing assembly are capable of being sealingly connected to each other, so as to fully achieve waterproof and dust-proof performance.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present application relates to a housing for an electronic device, and more particularly to a protective housing capable of protecting an electronic device inside and not affecting the use of the electronic device. 
         [0003]    2. Related Art 
         [0004]    Electronic devices, especially handheld portable electronic devices such as a communication device, a music or video player, a camera and so on, have become faithful companions of people that cannot be separated from in everyday life. However, use of the devices may face inconvenience. For example, humid environment or water, usage during exercise, or similar situations, might limit the usage of the device. Currently, although some electronic devices, such as a touch screen mobile phone, has a protective cover, usually the protective cover only has simple functions such as scratch-resistance, may severely affect operation and use of the mobile phone, and may bring much inconvenience during exercise, especially during mountain biking. 
         [0005]    In view of the gradual popularization of such devices and the increasing requirements of users on experience such as convenience, it is necessary to design a housing product which can better satisfy the user&#39;s needs. 
       SUMMARY 
       [0006]    In order to eliminate defects as listed above, the present application provides a housing for an electronic device, which does not reduce functions of a device, allows a user to fully use the device as if without the protective housing, and is dust-proof, antifouling, waterproof, protected against snow, shockproof, drop resistant, and protected against other environmental damage. The housing includes a main casing assembly for accommodating an electronic device and an end cover assembly working with the main casing assembly to seal the main casing assembly. The main casing assembly includes a main casing frame, a backplate, and a screen. The screen and the backplate are sealingly mounted on two opposite surfaces of the main casing frame respectively. A position, corresponding to a speaker or a microphone of the electronic device, on the main casing frame is provided with a hole, and a membrane capable of waterproof and sound transmission covers and is mounted on the hole. The end cover assembly includes an end cover and a sealing component fixedly connected to the end cover. A position, corresponding to the microphone or the speaker of the electronic device, of the sealing component is provided with a hole, and a membrane capable of waterproof and sound transmission covers and is mounted on the hole. When the main casing assembly and the end cover assembly are engaged with each other, a contact surface there between is further provided with a sealing ring. 
         [0007]    According to embodiments, the following preferred technical solutions may be adopted. 
         [0008]    The screen ( 10 ) is provided with geometry, the geometry is at least on the side which is facing the electronic device ( 1 ), to ensure a gap between the screen of the electronic device ( 1 ) and the screen ( 10 ). The geometry may be a arrangement of small bumps or lines, may also be realized as a frosted surface. 
         [0009]    The membrane capable of sound transmission is made of a plastic membrane or GORE-TEX membrane (material provided by U.S. Gore &amp; Associates. Inc.), and is provided with a slim groove for improving the quality of sound transmission. 
         [0010]    Positions, corresponding to function buttons of the electronic device, on the main casing frame are sealingly provided with corresponding function buttons respectively, and the function buttons include at least one of a home button, an on/off button, a volume button, and a mute switch button. 
         [0011]    The backplate is provided with a backplate over mold, the backplate includes a transparent PC material layer and a TPE rubber material layer acting as an optical reflection barrier, and positions, corresponding to a camera and a flash of the electronic device, on the TPE rubber material layer are provided with a camera lens and a flash lens capable of light transmission respectively. 
         [0012]    The end cover assembly further includes a foam sealing component for echo cancellation, and the foam sealing component is disposed on the sealing component. 
         [0013]    The end cover is further provided with a sound channel for guiding sound out of the housing, and the sound channel extends from a position, close to the sealing component, on the end cover to at least one end surface of the end cover. 
         [0014]    An embedded plug and an embedded jack connected to each other are disposed in the end cover, the embedded plug extends into the end cover and is connected to the electronic device in the end cover, and a jack of the embedded jack is exposed at a surface of the end cover. 
         [0015]    The end cover assembly further includes a locking/unlocking slide block, the main casing frame is correspondingly provided with a hook-shaped locking structure matching the locking/unlocking slide block, and the locking/unlocking slide block is disposed between the end cover and the sealing component and able to slide back and forth. 
         [0016]    The end cover is further provided with removable Plugs for sealing function interfaces on the end cover. 
         [0017]    The housing further includes an earphone extension cable capable of being removed and connected, a plug of the earphone extension cable is inserted in the end cover, a jack at the other end of the earphone extension cable extends out of the end cover. 
         [0018]    The locking/unlocking slide block holds the plug of the earphone extension cable for locking in a locked state, and releases the plug of the earphone extension cable for removal in an unlocked state. 
         [0019]    A nose is mounted on the earphone extension cable  4  and corresponding to the bump. 
         [0020]    The main casing assembly and a corresponding end portion of the end cover assembly are pivotal connected by a pivoting shaft and locked by a Strap, or a locking/unlocking slide block to lock the end cover assembly. 
         [0021]    Two sides of the main casing assembly  6  are provided with side rails respectively, and the main casing assembly  6  is further provided with a lanyard hole. 
         [0022]    Beneficial effects of the present embodiments are as follows. 
         [0023]    The end cover assembly and the main casing assembly are capable of being sealingly connected to each other, so as to fully achieve waterproof and dust-proof performance. The screen, the hole provided in the position corresponding to the speaker or the microphone of the electronic device, and the membrane covering the hole may at least ensure that basic operations and listening and speaking functions of the device are not affected. 
         [0024]    The plastic membrane or GORE-TEX membrane is not only waterproof, but also affects sound transmission as hardly as possible. The slim groove disposed on the membrane further optimizes or improves the effect of sound transmission. 
         [0025]    The function buttons and the camera lens and flash lens prevent the electronic device from being limited with respect to use, and all functions of the electronic device can be normally used. 
         [0026]    The foam sealing component for echo cancellation prevents echoes from occurring in the internal space of the housing, thereby ensuring the sound effect. 
         [0027]    The removable Plugs further improve the sealing effect, and are applicable to the regular harsh operating environment. 
         [0028]    The sound channel improves the sound effect of the product, thereby improving the using performance of the product. 
         [0029]    The embedded plug and the embedded jack connected to each other are disposed in the end cover, thereby making the use of an external earphone convenient. 
         [0030]    The locking/unlocking slide block prevents unexpected falling of the end cover from the main casing, and makes it convenient to remove the end cover when needed. 
         [0031]    The earphone extension cable makes it convenient to use an external earphone. 
         [0032]    The main casing assembly and a corresponding end portion of the end cover assembly are pivotal connected by a pivoting shaft, so that even if opened, the end cover assembly does not depart from the main casing assembly, thereby avoiding inconvenience caused by loss of the end cover assembly. 
         [0033]    The structural design of the side rails makes it convenient to fix the product to a specific accessory, thereby further facilitating usage. The lanyard may be tied to a hand or clothes through the lanyard hole on the main casing assembly  6 , thereby avoiding unexpected falling. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0034]    The present application will become more fully understood from the detailed description given herein below for illustration only, and thus are not limitative of the present application, and wherein: 
           [0035]      FIG. 1  is a schematic exploded view of an embodiment (including an electronic device, a protective housing, an earphone extension cable, and an auxiliary fixing accessory); 
           [0036]      FIG. 2  is a schematic exploded view of the protective housing  2  in  FIG. 1 ; 
           [0037]      FIG. 3  is a schematic exploded view of a main casing assembly; 
           [0038]      FIG. 4  is a schematic exploded view of an end cover assembly; 
           [0039]      FIG. 5  is a schematic enlarged view of a main casing frame  8 ; 
           [0040]      FIG. 6  is a schematic partially enlarged view (a front view) of one end of a main casing frame  8 ; 
           [0041]      FIG. 7  is a schematic view of a complete protective housing according to an embodiment; 
           [0042]      FIG. 8  is a schematic partially enlarged structural view of a backplate on which a backplate over mold is formed; 
           [0043]      FIG. 9  is a schematic structural view of another side surface of the backplate different from that in  FIG. 8 ; 
           [0044]      FIG. 10  is a schematic exploded view (a partial view) of assembly of an electronic device  1  and a protective housing  2 ; 
           [0045]      FIG. 11  is a schematic sectional view of an end cover assembly (secured with a Locking/unlocking slide block  14 ); 
           [0046]      FIG. 12  is a schematic structural view of a locking/unlocking slide block  14 ; 
           [0047]      FIG. 13  is a schematic structural view of an end cover provided with an embedded jack plug and an embedded jack; 
           [0048]      FIG. 14  is a schematic sectional view of  FIG. 13 ; 
           [0049]      FIG. 15  is a schematic structural view of a housing in which an end cover assembly and a main casing assembly are pivotal connected to each other by a pivoting shaft (the end cover assembly is opened at a certain angle); and secured with a Locking/unlocking slide block  14 ; 
           [0050]      FIG. 16  is a schematic sectional view of a partial structure when an earphone extension cable is inserted in a protective housing  2 . 
           [0051]      FIG. 17  is a schematic structural view of a housing in which an end cover assembly and a main casing assembly are pivotal connected to each other by a pivoting shaft (the end cover assembly is opened at a certain angle); and secured with a strap ( 38 ). 
           [0052]      FIG. 18  is a schematic view of screen  10  of an embodiment, displaying the setting of the pattern feature. 
           [0053]      FIG. 19  is a schematic partially enlarged view of  FIG. 18 . 
           [0054]      FIG. 20  is another schematic view of screen  10  of an embodiment, displaying another setting of the pattern feature. 
           [0055]      FIG. 21  is a schematic partially enlarged view of  FIG. 20 . 
       
    
    
       [0056]      
         [0000]    
       
         
               
             
               
               
               
               
               
             
           
               
                   
               
               
                 List of Reference Numerals: 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 1 
                 Electronic device 
                 41  
                 Nose 
               
               
                   
                 2 
                 Complete protective housing 
                 5 
                 Accessory 
               
               
                   
                 4 
                 Earphone extension cable 
                 6 
                 Main casing assembly 
               
               
                   
                 7 
                 End cover assembly 
                 21 
                 Home button 
               
               
                   
                 8 
                 Main casing frame 
                 22 
                 On/off button 
               
               
                   
                 9 
                 Backplate 
                 23 
                 Volume button 
               
               
                   
                 10 
                 Screen 
                 24 
                 Mute switch button 
               
               
                   
                 11 
                 Speaker membrane 
                 25 
                 Side rail 
               
               
                   
                 12 
                 End cover 
                 26 
                 Side rail locking feature 
               
               
                   
                 13 
                 Sealing component 
                 27 
                 Lanyard hole 
               
               
                   
                 131 
                 Sealing Component Groove 
                 28 
                 Backplate over mold 
               
               
                   
                 14  
                 Locking/unlocking slide block 
                 29 
                 Backplate camera lens 
               
               
                   
                 141 
                 Locking/unlocking button 
                 30 
                 Backplate flash lens 
               
               
                   
                 142 
                 bump 
                 31 
                 Noise-cancelling hole 
               
               
                   
                 143 
                 Locking Pin 
                 32 
                 Sound channel 
               
               
                   
                 144 
                 Retaining Hook 
                 34 
                 Embedded jack plug 
               
               
                   
                 15 
                 Plug 
                 35 
                 Embedded jack 
               
               
                   
                 16  
                 Sealing ring 
                 36 
                 Wire 
               
               
                   
                 17 
                 Microphone membrane 
                 37 
                 Pivoting shaft 
               
               
                   
                 18 
                 Foam sealing component 
                 38 
                 Strap 
               
               
                   
                 19 
                 Hook-shaped locking structure 
                 101 
                 samll bumps 
               
               
                   
                 20 
                 Sealing surface 
                 102 
                 lines 
               
               
                   
                   
               
             
          
         
       
     
       DETAILED DESCRIPTION 
       [0057]    The present application is further illustrated below in detail with reference to embodiments and the accompanying drawings. 
         [0058]    As shown in  FIG. 1  to  FIG. 4  and  FIG. 15 , a protective housing  2  for a electronic device  1  (for example, a touch screen mobile phone iPhone 5) includes a main casing assembly  6  for accommodating an iPhone 5 and an end cover assembly  7  working with the main casing assembly  6  to achieve sealed connection. The main casing assembly  6  includes a main casing frame  8 , a backplate  9 , and a screen  10 . The screen  10  and the backplate  9  are sealingly mounted on two opposite surfaces of the main casing frame  8  respectively. A position, corresponding to a speaker (or a microphone) of the electronic device, on the main casing frame  8  is provided with a hole. A speaker membrane  11  capable of waterproof and sound transmission covers and is mounted on the hole. The end cover assembly  7  includes an end cover  12  and a sealing component  13  fixedly connected to the end cover  12 . A position, corresponding to the microphone (or the speaker) of the electronic device, on the sealing component  13  is provided with a hole. A microphone membrane  17  capable of waterproof and sound transmission covers and is mounted on the hole. When the main casing assembly  6  and the end cover assembly  7  are engaged with each other, a contact surface therebetween is further provided with a sealing ring  16  for sealing. Further, an earphone extension cable  4  and a rail system facilitating fixing of the product on a fixing frame are included. 
         [0059]    The complete main casing assembly  6  includes the main casing frame  8 , which is integrally assembled with the backplate  9 , the screen  10  and the speaker membrane  11  in advance, and the neighboring components are mutually sealed, as shown in  FIG. 3 . The backplate  9  and the screen  10  may be assembled and fixed permanently by gluing, ultrasonic welding, laser welding or any other means, and are not to departed or removed from the main casing frame  8  by normal usage. The speaker membrane  11  may be assembled by using a double-sided adhesive, gluing, or ultrasonic welding. The complete main casing assembly  6  is provided with a step for assembling the screen  10 . The screen  10  is a transparent foil which is made of any proper material, such as PC, PET or PMMA for example, but not limited. The speaker membrane  11  may be made of a thin plastic membrane or other materials such as a Gore-Tex membrane or other membrane capable of venting and being waterproof, which allows sound transmission and ensures sealing performance in water. Further, the speaker membrane  11  may be in a special shape, such as a slim groove or other geometric shapes, so as to improve the sound quality. Geometric shapes such as the slim groove may be fabricated by compressing, deep drawing, or other methods. 
         [0060]    As shown in  FIG. 5 , the main casing frame  8  is formed in a mold with a slide block opening/closing manner at the top or the bottom (depending on that the housing is closed through the top or the bottom), so as to ensure that a sealing surface  20  of the main casing frame  8  from which the mold is stripped does not have any parting line. In this embodiment, the main casing frame  8  includes plastics of different hardness levels, for example, includes a layer of TPE (soft rubber) over mold and another layer of) hard plastic (for example PC), or two kinds of plastics formed through double component injection. The main casing frame  8  integrates functional buttons, such as a home button  21 , an on/off button  22 , a volume button  23 , and a mute switch button  24 , as shown in  FIG. 7 . When the iPhone 5 or electronic device is put in the complete protective housing  2 , a user is allowed to use all functional buttons of the electronic device  1 . The functional buttons are formed in the over mold material of the main casing frame  8 , so as to achieve flexibility and sealing performance. The mute switch button  24  enables the user to mute the electronic device  1  when the protective housing  2  is used. 
         [0061]    As shown in  FIG. 8 ,  FIG. 9 , and  FIG. 10 , the backplate over mold  28  of the backplate  9  ensures the integration of a camera lens  29  and a flash lens  30 . The camera lens  29  and the flash lens  30  may be integrally formed with the backplate  9  (over molding or dual-component injection), or may be independent members sealingly inserted into the backplate  9 . In this embodiment, the backplate  9  includes a transparent PC housing material layer and a TPE rubber material layer, backplate over mold  28 , so as to be able to act as an optical reflection barrier between a flash and a camera, so that when the flash is used, pictures taken are ensured to be clear. Further, the backplate over mold  28  has an integrated noise-cancelling feature  31 , which enables a noise-cancelling hole of the electronic device  1  to be sealed off against any sound, noise or water ingress. The noise-cancelling hole is located in the electronic device  1 , can reduce ambient noise during conversation, the backplate  9  and has three possible configuration manners: 1) The noise-cancelling hole is sealed opposite to the protective housing  2 , and no membrane for sound transmission exists therebetween, so as to achieve the optimal sound quality. 2) The noise-cancelling hole  31  is completely sealed opposite to the protective housing  2 , and no internal membrane exists. 3) No sealing is performed between the electronic device and the protective housing  2 , which results in poor sound quality. Specifically, in this embodiment the second configuration manner is adopted. The camera lens  29  and the flash lens  30  are sealingly inserted into the backplate  9  as independent members will not affect the photo-taking, even the backplate  9  is made out of colorful material. 
         [0062]    The screen  10  is a touch screen membrane, for example a thin transparent plastic membrane, which may be assembled by insert molding, over molding, gluing, ultrasonic welding, laser welding, or adhesive connecting. The touch screen membrane may have a special coating, so as to have improved performance on scratch-resistance, fog-resistance and glare reduction or other special functions. 
         [0063]    As shown in  FIG. 4 , the complete end cover assembly  7  mainly includes the end cover  12  and the sealing component  13 . The end cover  12  and the sealing component  13  may be assembled by gluing, ultrasonic welding, laser welding, or any other means capable of fixing the end cover  12  and the sealing component  13 . As shown in  FIG. 11 , a sound channel  32  for guiding sound out of the protective housing is further disposed between the end cover  12  and the sealing component  13 . The sound channel  32  is formed by the end cover  12  and the sealing component  13 , and extends from a position, close to the sealing component  13 , on the end cover  12  to at least one end surface of the end cover. 
         [0064]    The microphone membrane  17  disposed in the end cover  12  may be assembled by using a double-sided adhesive, gluing, and ultrasonic welding, and may be made of a thin plastic membrane or other materials such as a Gore-Tex membrane, which allows sound transmission and ensures sealing performance in water. Further, the microphone membrane  17  may be in a special shape, such as a slim groove or other geometric shapes, so as to improve the sound quality. Geometric shapes such as the slim groove may be fabricated by compressing, deep drawing, or other methods. 
         [0065]    The end cover assembly  7  includes a foam sealing component  18  for echo cancellation, which is disposed on the sealing component  13 , as shown in  FIG. 4 . The foam sealing component  18  may be assembled with the sealing component  13  in any manners, so as to ensure soundproofing between the electronic device  1  and the complete end cover assembly  7 . That is to say, the foam sealing component  18  ensures that sound from the electronic device is not transmitted into the microphone, so as to eliminate or minimize any echo effect. 
         [0066]    One end of the Plug  15  is fixed permanently by mounting it on the end cover  12  and the sealing component  13 , so that the other end of the plug  15  may be removed from the end cover  12 , so as to allow the earphone extension cable  4  with an extension plug to enter the housing to be connected to the electronic device  1  when needed, as shown in  FIG. 4  and  FIG. 16 . 
         [0067]    The sealing ring  16  between the main casing assembly  6  and the end cover assembly  7  may be an O-ring, which is on the sealing surface  20  of the complete main casing assembly  6 , so as to prevent water and dirt from entering the protective housing  2 . The sealing ring  16  is compressed in a radial direction by the end cover assembly  7 , so as to prevent any unexpected failing during use. The O-ring is preferably made of a material which is durable, environmentally friendly, and chemically stable, and the waterproof level shall be, at least IP68 or higher with a specified depth and time of immersion needed, so that underwater use and severe environment use is allowed. 
         [0068]    The end cover assembly  7  may be a completely independent component, or may be pivotal connected to the main casing frame  8  by using a rotary shaft  37  and a strap  38  or a locking/unlocking slide block  14 , to lock the end cover assembly to the main casing frame  8 . As shown in  FIG. 15 , in this embodiment, the rotary shaft  37  is used for pivot-connection, and the end cover assembly  7  may be opened at a certain angle. the lanyard hole should be on the main casing assembly  6 . As shown in  FIG. 7 , in this embodiment, the end cover assembly  7  has a locking/unlocking slide block  14 , which interacts with a hook-shaped locking structure  19  of the main casing frame  8 , so as to realize locking and unlocking therebetween, as shown in  FIG. 6 . Specifically, as shown in  FIG. 12 , by using the locking/unlocking button  141  the locking/unlocking slide block  14  can be moved in two directions for locking and unlocking. In a locked state, that is, when a two locking pins  143  are interlocked with the corresponding hook-shaped locking structure  19  of the main casing frame  8 , the end cover assembly  7  cannot be separated from the main casing assembly  6 , and meanwhile the earphone extension cable  4  cannot be pulled out, because the bump  142  disposed at the end of the locking/unlocking slide block  14  is pushed against the earphone extension cable And interlocks with the nose  41  of the extension cable. In an unlocked state, that is, when the locking pins  143  are disengaged from the hook-shaped locking structure  19  of the main casing frame  8  and the bump  142  is separated from the earphone extension cable  4 , the end cover assembly  7  may be removed from the main casing assembly  6 , and/or that the earphone extension cable  4  can be pulled out. According to the design, after the end cover  12  and the sealing component  13  are assembled, the locking/unlocking slide block  14  cannot be removed, and meanwhile the locking/unlocking slide block  14  locks the earphone extension cable  4 , so as to prevent any unexpected separation of the earphone extension cable  4  during use. Two retaining hooks  144  on the locking/unlocking slide block  14  which are interacting with two sealing component grooves  131  on the sealing component  13 , make sure that the locking/unlocking slide block  14  stays in the locked or unlocked position. As shown in  FIG. 1 ,  FIG. 12  and  FIG. 15 , preferred, a nose  41  is mounted on the earphone extension cable  4  and corresponding to the bump  142 , so as to improve the reliability assurance of locking the earphone extension cable  4 . 
         [0069]    As shown in  FIG. 13  and  FIG. 14 , the end cover assembly  7  of this embodiment may further be provided with a built-in earphone plug adapter, and the direction of the adapter may be straight or may face any side and be at any angle. The adapter includes an embedded jack plug  34  and an embedded jack  35  connected by a wire  36 . When the end cover assembly  7  is assembled to the main casing assembly  6 , the embedded jack plug  34  is reliably connected to the electronic device  1  in the protective housing. 
         [0070]    As shown in  FIG. 1 , The rail system mainly includes an auxiliary fixing component, e.g. accessory  5 , and the component has an integrated locking mechanism on the bottom, which is applicable to an extra fixing system, such as bicycle fixing, helmet fixing, screw fixing, a tripod, or any other support device. Meanwhile, two side rails  25  are disposed on two sides of the main casing frame  8 , and the side rails  25  may be engaged with two snapper rails on the inside of the accessory  5  to connect the complete protective housing  2  with the accessory  5  when needed. Two side rail locking feature  26  ensure a secure position in the accessory due to snapping interaction between accessory  5  and main casing frame  8 . 
         [0071]    As shown in  FIG. 17 , is a schematic structural view of another embodiment. In Comparison with  FIG. 15 , the locking/unlocking slide block  14  is replaced by the strap  38 . 
         [0072]    For a better user experience, the screen  10  can feature some sort of pattern such as small bumps, lines, or other geometries, such as crosses or any other shape. The pattern is at least on one side, where it touches the screen of the electronic device  1 . The distance between each of the single elevated features in the pattern can be of different length. The pattern may also be realized as a frosted surface, and therefore by irregular. The following is the detailed description. 
         [0073]    As shown in  FIGS. 18 and 19 , the screen  10  is provided with small bumps  101  on the side which is facing the the electronic device  1 . The small bumps  101  are uniform distribution (can also be nonuniform distribution) and touch the the screen of the electronic device  1 , be used for: A. To ensure a minimal gap between the screen of the electronic device and the screen  10 . The gap prevents the two surfaces (the screen of the electronic device  1  and the screen  10 ) to stick together through capillary force. B. Helps to release the device  1  out of the case  2 , when disassembling the main case and the electronic device  1 . Act as an extra protection to the screen of the electronic device by providing a small gap acting as an air cushion. 
         [0074]    The pattern may be made by embossing, stamping, UV printing or other printing method. 
         [0075]    As shown in  FIGS. 20 and 21 , the screen  10  is provided with geometries  102  which is featured by hot processing and uniform distribution. On the side which is facing the electronic device  1 , each geometry presents as convex surface, on the other side presents as concave surface. The foregoing several technical effects can surely be reached by this way. 
         [0076]    The foregoing content is detailed description of the present application with reference to the specific preferred embodiments, but it cannot be considered that the specific implementation of the present application is limited to the description. Several equal replacements or obvious variations with the same performance and usage made by persons of ordinary skill in the art without departing from the idea of the present application all should be construed as falling within the protection scope of the present application.