Patent Publication Number: US-7223127-B2

Title: Thin USB electronic device

Description:
This application is a Continuation-In-Part of application Ser. No. 11/138,381 filed on May 27, 2005, now U.S. Pat. No. 7,090,541, the entire contents of which are hereby incorporated by reference and for which priority is claimed under 35 U.S.C. 120. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention discloses a USB electronic device and specially relates to a thin USB electronic device. 
   2. Description of the Prior Art 
   With the progress in the information technology (IT) industry, portable electronic devices become more and more popular. Some of them, such as a flash drive or a small memory card, are capable of communicating with host (PC or notebook computer) through specific transmission interfaces, in which the universal serial bus (USB) is the most popular one. Because the USB is one of the most popular I/O interfaces in current personal computers, many electronic devices adopt USB as their transmission interface. The advantage of utilizing the USB is that it reduces the usage of a card reader for portable devices with different I/O interface. 
   Conventionally the connector for the USB electronic device is separated from the circuit board, and fabricated together by a weld. Because the USB connector&#39;s limitations, however, the USB electronic device will become too thick to be portable. Referring to  FIG. 1 , the housing  100  of the USB connector will influence and increase the volume and thickness of the electronic device. In order to reducing the thickness of all electronic elements among the electronic device as possible, the most regular solution is to improve the USB connector&#39;s structure, or to apply a connector-less design for thinning out the USB electronic device. Referring to  FIG. 2A  and  FIG. 2B , Taiwan patent number 570242 discloses a USB storage device, therein the connector  202  is extended from the circuit board and enclosed in an upper housing  200  and a lower housing  201 . By utilizing the contacts of a USB receptacle to touch the metal film  204  electroplated directly on the connector  202 , the USB storage device could establish a circuit loop with the host. However, most parts of the connector  202  are exposed from the device housing, making the contacts (formed of metal films) short circuit easier by external matter, which decrease the electronic device&#39;s life. 
     FIG. 3  illustrates the simplified structure of a small USB connector disclosed in Taiwan patent number 565026, therein connector  30  and circuit board  31  are manufactured whole in one and placed in the lower housing  38 . The upper housing  37  merely covers parts of the connector  30  and forms the device&#39;s housing with the lower housing  38 . In addition, four metal strips  33  are adhered on the connector  30  as the contacts for communicating with an USB receptacle (not shown). However, the connector  30  still reveals too much to outside environment. Further, because it&#39;s necessary to drill on the connector  30  before adhering the metal strips  33 , and a metal housing  39  shaped of U letter is also needed for protecting the connector  30 , the structure of the USB electronic device becomes more complicated and harder to fabricate, resulting in difficulties in reducing production costs. 
   According to the above descriptions, the foregoing two inventions may achieve the goal for a thin USB electronic device, but there are still some disadvantages to overcome. Therefore, there is need to further reduce the thickness of the USB connector and the thickness of the USB electronic device, to overcome the foregoing disadvantages, and provide more protection for the connector (especially contacts of USB electronic device). 
   SUMMARY OF THE INVENTION 
   As the shortcomings of conventional USB devices are discussed in the prior art, an objective of the invention is to provide a USB electronic device which having a thin structure. 
   A another objective of the invention is to provide an improved USB electronic device, in which the substrate and other electronic elements are substantially enclosed for preventing the connector and the contacts of the USB electronic device to become unnecessarily revealed, thereby gaining more protection. 
   A further objective of the invention is to provide an improved USB electronic device, in which every opening corresponds to a metal strip to make the improved USB electronic device functional for guiding each contact of an USB receptacle into the right position, and prevent mutual influences between the two metal strips or short circuit caused by external matter. 
   In accordance to the foregoing objectives of the invention a USB electronic device is disclosed, which comprises a substrate having a circuit board and a connector extending from the circuit board. Some metal strips adhere onto the connector, which is then electrically connected to the circuit board. At least one integrated circuit is mounted on the substrate, and a housing has openings, through which the corresponding metal strips are exposed and are electrically communicable with the contacts of a USB receptacle. 
   In another embodiment, the metal strips are replaced by metal film and the inner integrated circuit components are allocated centrally beneath the circuit board. Besides, a bulge section is formed upon the lower housing to sustain the substrate for increasing the structure&#39;s stability. 
   Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the following detailed description and the accompanying drawings, which are given by why of illustration only, and thus are not limitative of the present invention, and in which: 
       FIG. 1  illustrates a conventional USB connector; 
       FIG. 2A  and  FIG. 2B  respectively illustrates a USB connector&#39;s structure of the prior art and its explosion drawing; 
       FIG. 3  illustrates the explosion drawing of a USB connector of another prior art; 
       FIG. 4A  is the preferred embodiment of the invention; 
       FIG. 4B  is the explosion drawing of the preferred embodiment of the invention; 
       FIG. 4C  is the side view for substrate of the preferred embodiment; 
       FIG. 4D  shows the side view of the preferred embodiment of the invention and an USB receptacle; 
       FIG. 4E  shows the front view of the preferred embodiment of the invention and an USB receptacle; 
       FIG. 5A  illustrates an another embodiment of the present invention; and 
       FIG. 5B  illustrates the explosion drawing of the embodiment of  FIG. 5A . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   The preferred embodiment of the present invention is now described in great detail. Nevertheless, it should be recognized that the present invention can be practiced in a wide range of embodiments besides those explicitly described, and the scope of the present invention is expressly not limited except as specified in the accompanying claims. 
     FIG. 4A  illustrates a thin USB electronic device, which is the preferred embodiment of the invention, and specially the USB electronic device is an USB storage device. The arrow indicates the direction of the USB electronic device while inserting into an USB receptacle. The disclosed USB electronic device is enclosed with a housing  4 , which opens some openings  402  (four in this embodiment) for exposing inner metal strips  46  as the contact for communicating with the USB receptacle of a host. 
     FIG. 4B  is the explosion drawing of the preferred embodiment of the invention illustrating in  FIG. 4A . Referring to  FIG. 4B , the inner structure is distinctly revealed, therein every composing element of the USB electronic device are substantially enclosed in the upper housing  40  and lower housing  41 . The composing elements include a substrate  43 , which further comprises a circuit board  431  having an essential circuit layout, and a connector  432  extending from the circuit board  431 . The preferred material of substrate  43  in this embodiment is a printed circuit board (PCB). 
   Metal strips  46 , such as bronze strips, are adhered to a connector  432 , and electrically connecting to the layout of circuit board  431 . Means for fixing metal strip  46  on connector  432  are not limited, in which surface-mount technology (SMT) is preferred and applied in the embodiment. By reference to SMT, metal strips  46  directly adhere on connector  432  as the contacts for communicating with USB receptacle, advantaging of avoiding drilling on connector  432  which simplifies manufacture and reducing the costs. 
   A memory  44 , such as a FLASH RAM, is mounted beneath substrate  43  for storing data. Besides, the bottom of substrate  43  further comprises a USB controller  45  for transforming an incoming USB signal into data and storing in the memory  44 , or transforming the data stored in memory  44  into a USB signal to communicate with the host through metal strips  46 . 
   It is noted that other elements except memory  44  and USB controller  45  could be mounted on the substrate  43 . Furthermore, the memory  44  and USB controller  45  could be replaced by other type of integrated circuit. In other words, applications of the invention are not limited as a storage device, but applicable to the electronic devices of other purpose. 
   In order to achieve the goal for a thin USB electronic device, memory  44 , USB controller  45 , and metal strips  46  are designed as thin as possible. Besides, putting memory  44 , USB controller  45 , or other elements on the same side of substrate  43  (bottom in this embodiment) avoids increasing the thickness compared to putting them on both sides of the substrate  43 . Hence, referring to  FIG. 4C , in which memory  44  is mounted beneath the circuit board  431  and the USB controller  45  is mounted beneath the connector  432  for optimizing the usage of space. 
   In the preferred embodiment of the invention, openings  402  sets on the upper housing  40  are counted in four and strip-shaped, and certainly the width of each opening and the interval between two adjacent openings should be compatible with the USB standard. Through openings  402  only metal strips  46  are exposed from the upper housing  40 . In other words, each metal strip corresponds to an opening and partially exposed part of the upper housing  40  as contacts for electrically communicating with the USB receptacle. Because the height of the metal strips  46  is lower than the surface of the upper housing  40 , hence the thickness of the invention won&#39;t be increased, and a flatter structure for USB electronic devices will be achieved. In addition, the upper housing  40  near the front end of each openings  402  further forms a inclined plane which has the advantage of making the contacts of the USB receptacle more smooth to touch the metal strips  46 . 
   Comparing to the prior arts, the major difference is that there are pluralities of openings opened on the device housing to merely expose the metal strips excluding the other areas of the connector. The particular structure design for the device housing benefits in many ways. First, because every exposed metal strip is separated from each other by the upper housing  40 , it&#39;s more difficult to bring about short circuits between the two metal strips cause by external matter. Second, except for parts of metal strips  46 , the other areas of the connector  432  are totally enclosed in the housing  4 , hence it makes less of an exposed area of the connector of the invention than that of the prior art. Besides, the height of metal strips  46  are lower than the surface of the upper housing  40 , therefore the USB connector is harder to be stressed by foreign matter and thus obtains more protection. Furthermore the upper housing  40  isolates each metal strip with a relative higher surface, guiding the contacts of the USB receptacle to the corresponding metal strip, which prevents more than one contacts of the USB receptacle erroneously touching the same metal strip. 
   In addition, housing  4  may make some variations to the design to achieve more functions, for example, the upper housing  40  may further form a hole  408 .  FIG. 4D  shows the side view of the invention and the USB receptacle, in which the preferred embodiment of the invention is inserting into the USB receptacle from right to left. For USB receptacle  49  having a larger depth and inner volume, it&#39;s feasible to add a bolt  495  to lodge in hole  408 . As the preferred embodiment of the invention inserting into USB receptacle  49 , bolt  495  and contacts  492  slightly lift till the disclosed USB electronic device is in the right position. Among them through openings  402  contacts  492  touch the metal strips, and bolt  495  inserts in the hole  408  to fasten the electronic device, which achieves more robust connection with the USB receptacle  49 . 
   Furthermore, flanks of housing  4  may form incline  405 ,  406  as shown in  FIG. 4A , thereby resulting in asymmetry of the disclosed electronic device. For a USB receptacle shaped as shown in  FIG. 4E , if the electronic device is overturned, the triangular corner  497 ,  498  will block the bottom sides of electronic device ( 417 , 418 ). It means the incline  405 ,  406  provides a foolproof mechanism that insures reverse insertion is denied. It&#39;s stressed that, the incline  405 , 406  is not only limited to form on the top flanks of the housing  4 , but also the bottom, top and bottom of one flank, or only one incline  405  is permitted. With a compatible USB receptacle, the USB electronic device of the invention achieves a foolproof function. Besides, hole  408  and the incline  405 ,  406  are optional, the designer for the electronic device may decide by himself if applying the foregoing design is needed or not. 
     FIG. 5A  depicts the appearance look for a thin USB electronic device with an another embodiment of the present invention, and  FIG. 5B  is the explosion drawing of  FIG. 5A , which reveals the inner components and the structure of the USB electronic device. The original incline structure at the flanks of the housing are replaced with the various design (L-shaped structure  505   506 ) shown in  FIG. 5A , and also provides foolproof mechanism. There are still four openings  502  placed upon the upper housing  50 . Since the structure, shapes and functions of the four openings are the same to the previous embodiment, they will not be explained redundantly hereafter. 
   Similarly, the proposed electronic device may be divided into an upper housing  50 , a lower housing  51  and the intermediate substrate  53 . Also, the substrate  53  can be further divided into a circuit board  531  and an extended connector  532 . The same to the previous embodiment, the preferred material for the substrate  43  is the print circuit board. In this embodiment, one side of the connector  532  has several contacts (golden fingers), which are formed of rectangular electronic conductive metal film perpendicular for each another, to communicate with the USB receptacle, and the another side is electrically communicated to the layout upon the circuit board  531 . The substrate  53 , especially beneath the circuit board  531 , allocates several integrated circuit components, such as the memory  54  and the USB controller (not shown in the drawing), for storing inputted data. 
   The different points to the previous embodiment include, using metal film to form the contacts of USB electronic device and allocating most components centrally beneath the circuit board  531 . One advantage of using metal film is the cheaper unit cost (compare to metal strip); besides, the metal film  56  may be manufactured as the same time as laying the transmission line upon the circuit board  531  (In other words, the metal film  56  may be extended directly from the layout of the circuit board  531 ), thereby simplifying the manufacturing process. Furthermore, to allocate both the memory  54  and the USB controller beneath the circuit board  531  may reduce length of the transmission line upon the circuit board, which also reduces the manufacturing cost. 
   However, the connector  532  is unsupported and suspended in the housing  5 . Hence, in order to increase the structure&#39;s stability, a bulge section  512  is manufactured upon the inside face of the lower housing  51  to sustain the connector  532 . Thickness of the bulge section  512  is about the same to the height of the memory device  54  (or the USB controller), and shapes or numbers of bulge section  512  are not limited to the present embodiment. 
   For the above descriptions, the disclosed invention achieves several advantages such as: achieving the major goal of the invention for a thin USB electronic device; the particular design for openings through which merely exposes the essential metal strips/film results in providing the connector and adhered contacts more protection than the prior art; and furthermore, the structure/shape of the housing may design optionally with a hole over the housing for fastening the USB electronic device, or forms at least one incline as a foolproof mechanism. In another embodiment of the present invention, the contacts and the position of the inner components of the present USB device varies to acquire different advantages. Hence, obviously the disclosed USB electronic device of the invention is superior to the prior art, and the invention is novel and progressive. 
   The above-mentioned are only the preferred embodiments of the present invention, not intended to limit the scope thereof. It will be appreciated and carried out by those professions skilled in the art. Thus, many modifications of the embodiments that can be made without departing from the spirit of the present invention should be covered by the following claims.