Patent Publication Number: US-6991489-B2

Title: Connection device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application claims priority of Taiwan Patent Application Serial No. 092204277 entitled “Connection Device”, filed Mar. 19, 2003. 
   FIELD OF THE INVENTION 
   The present invention relates to a connection device. Particularly, the present invention relates to a connection device for connecting to a flat flex cable. 
   BACKGROUND OF THE INVENTION 
     FIG. 1  shows a prior art connection device for connecting a first electrical device  100  to a second electrical device  101 . As shown in  FIG. 1 , the connection device includes a dielectric housing  200 . The dielectric housing  200  has a slot  202  for plugging in the first electrical device  100 . The slot  202  defines a top surface  204  and a bottom surface  206 . A first bulge portion  301  extends downward from the top surface  204 , and a second bulge portion  303  extends upward form the bottom surface  206 . A conductive layer  300  is selectively formed on the surface of the first bulge portion  301 , and/or a conductive layer  400  is selectively formed on the surface of the second bulge portion  303 . The first bulge portion  301  corresponds to the second bulge portion  303  for electrically coupling to the first electrical device  100 . 
   As shown in  FIG. 1 , the first electrical device  100  has a single point of contact with the connection device. Thus, the first electrical device  100  tends to shift or rotate around the single point of contact when the first electrical device  100  moves relative to the second electrical device  101 . After extended use, the first electrical device  100  often becomes loose, resulting in poor contact, which in turn leads to low electrical connectivity and poor signal transmission. This phenomenon is especially common among optical pick-up head connection devices in optical disc drives. 
   Therefore, a new connection device is required to improve the connection between the first electrical device  100  and the second electrical device  101  so that poor contact or poor signal transmission does not occur when the second electrical device  101  moves or rotates relatively to the first electric device  100 . 
   SUMMARY OF THE INVENTION 
   It is one aspect of the present invention to provide a connection device for connecting a first electrical device to a second electrical device. 
   It is another aspect of the present invention to provide a connection device for preventing the first electrical device from shifting or rotating so that poor contact or poor signal transmission does not occur. 
   The connection device includes a dielectric housing having a slot formed therein to allow the electrical device to plug in. The slot includes a top surface and a bottom surface. A first bulge portion and a second bulge portion extend downward from the top surface. A third bulge portion and a fourth bulge portion extend upward from the bottom surface. The first bulge portion corresponds to the third bulge portion for clamping the electrical device. The second bulge portion corresponds to the fourth bulge portion for electrically coupling to the electrical device. The distance between the first bulge portion and the third bulge portion is larger than the distance between the second bulge portion and the fourth bulge portion. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a cross-sectional view of the prior art connection device; 
       FIG. 2  is a connection device in accordance with the present invention; 
       FIG. 3  is a cross-sectional view of a connection device of a first embodiment in accordance with the present invention; 
       FIG. 4  is a cross-sectional view of a connection device of a second embodiment in accordance with the present invention; 
       FIG. 5  is a cross-sectional view of a connection device of a third embodiment in accordance with the present invention; and 
       FIG. 6  is a cross-sectional view of a connection device of a fourth embodiment in accordance with the present invention. 
   

   DETAILED DESCRIPTION 
   As shown in  FIG. 2 , the present invention provides a connection device for connecting a first electrical device  100  to a second electrical device  101 . The first electrical device  100  can be a flat flex cable (FFC), a flexible printed circuit (FPC), a wire, a cable, a golden finger, a membrane circuit, or the like. The second electrical device  101  can be an optical pick-up head, a photo sensor, a motor, a speaker, an optical disc drive, or any other similar device. In this embodiment, the first electrical device  100  is a flat flex cable and the second electrical device  101  is an optical pick-up head. The optical pick-up head connects to the flat flex cable by the connection device in accordance with the present invention. 
     FIG. 3  is a cross-sectional view of a connection device of a first embodiment in accordance with the present invention. As shown in  FIG. 3 , the connection device includes a dielectric housing  200 . The dielectric housing  200  has a slot  202  for plugging in the first electrical device  100 . The slot  202  defines a top surface  204  and a bottom surface  206 . A first bulge portion  401  and a second bulge portion  403  extend downward from the top surface  204  of the slot  202 . A third bulge portion  405  and a fourth bulge portion  407  extend upward from the bottom surface  206  of the slot  202 . The first bulge portion  401  corresponds to the third bulge portion  405  for clamping the first electrical device  100 . The second bulge portion  403  corresponds to the fourth bulge portion  407 . Either the second bulge portion  403  selectively has a conductive layer  300  for electrically coupling to the first electrical device  100 , and/or the fourth bulge portion  407  selectively has a conductive layer  400  for electrically coupling to the first electrical device  100 . It should be noted that the conductive layer  300  of the second bulge portion  403  and the conductive layer  400  of the fourth bulge portion  407  may be concurrently applied. In addition, the first bulge portion  401  and the third bulge portion  405  may selectively have a conductive layer. 
   Furthermore, the first bulge portion  401  includes a first horizontal surface  410  and the third bulge portion  405  includes a second horizontal surface  420 . With larger contact areas between the first horizontal surface  410  and the first electric device  100 , and between the second horizontal surface  420  and the first electric device  100 , the present invention clamps the first electrical device  100  more firmly than the prior art. When an external force (e.g. shock, vibration, etc) accidentally acts on the first electrical device  100 , the clamping force between the first horizontal surface  410  and the second horizontal surface  420  prevents the first electrical device  100  from shifting or rotating. 
     FIG. 4  is a cross-sectional view of a connection device of a second embodiment in accordance with the present invention. As shown in  FIG. 4 , the second bulge portion  403  and the fourth bulge portion  407  each further includes a horizontal surface to provide additional clamping force. It should be noted that although the first horizontal surface  410  and the second horizontal surface  420  are shown in pairs in  FIG. 3  and  FIG. 4 , those skilled in the art could easily know that they may be applied independently. 
     FIG. 5  is a cross-sectional view of a connection device of a third embodiment in accordance with the present invention. As shown in  FIG. 5 , the distance between the first bulge portion  401  and the third bulge portion  405  is larger than the distance between the second bulge portion  403  and the fourth bulge portion  407 . The first bulge portion  401  and the third bulge portion  405  will compress the first electrical device  100  while clamping the first electrical device  100 . The smaller distance between the second bulge portion  403  and the fourth bulge portion  407  ensures good electrical contact with the first electrical device  100  even when the first electrical device  100  is compressed and becomes thinner. 
   As shown in  FIG. 3  to  FIG. 5 , it should be noted that the connection device clamps the first electrical device  100  by using the first bulge portion  401  in conjunction with the third bulge portion  405  and by using the second bulge portion  403  in conjunction with the fourth bulge portion  407 . These two pairs of clamping regions can provide better clamping force to hold the first electrical device  100  in place. When the external force accidentally acts on the first electrical device  100 , the first bulge portion  401  and the third bulge portion  405  serve as a buffer region to decrease the effect of the external force. Thus, the second bulge portion  403  and the fourth bulge portion  407  will not be affected by the external force and will keep good electrical connectivity with the first electrical device  100 , ensuring good electrical current and signal transmission. 
     FIG. 6  is a cross-sectional view of a connection device of a fourth embodiment in accordance with the present invention. As shown in  FIG. 6 , the second bulge portion  403  further includes a first sloping surface  510 , and the fourth bulge portion  407  further includes a second sloping surface  520 . When the first electrical device  100  is plugged into the slot  202 , the first sloping surface  510  and the second sloping surface  520  serve as guiding surfaces. In this embodiment, a first angle  511  between 30 and 60 degrees is formed between the first sloping surface  510  and the top surface of the first electrical device  100 , and a second angle  521  between 30 and 60 degrees is formed between the second sloping surface  520  and the bottom surface of the electrical device  100 . It should be noted that although the first sloping surface  510  and the second sloping surface  520  are shown in pairs in  FIG. 6 , those skilled in the art could easily know that they might be applied independently. 
   While the preferred embodiments and applications of the invention have been described, it is apparent to those skilled in the art that the objects and features of the present invention are only limited as set forth in the claims attached hereto.