Patent Publication Number: US-2006005210-A1

Title: Two-way disc clamping mechanisms and multiple disc read and write systems

Description:
BACKGROUND  
      The invention relates to two-way disc clamping mechanisms and multiple disc read and write systems.  
      Due to technology development and higher user requirements, disc drives for entertainment, such as home or automobile video disc drives, have developed from traditional single disc drives to multiple disc systems capable of storing 4, 6, or more discs.  
      As video resolution or audio quality increases, a greater number of discs are required for storage of movies, music, and the like. Thus, disc cabinets capable of storing several hundred discs have been developed. Typically, discs are placed vertically to simplify design. Vertical disc cabinets however occupy a large amount of space. Alternatively, discs are placed horizontally, thus reducing the required space but complicating disc clamper design.  
      Disc cabinets require disc changers to access and move discs between storage locations and read and write locations. Disc changers comprise disc clampers, typically with a semicircular shape, for clamping discs by their edges. Despite different disc thicknesses, the size of a conventional semicircular disc damper is typically about the size of a disc, thus consuming excessive space.  
     SUMMARY  
      A two-way disc clamping mechanism is provided. An exemplary embodiment of a two-way disc clamping mechanism comprises a frame, two parallel support components, two parallel clamp components, an L-shaped drive component, and a spring. The two parallel support components are rotatably hinged on the frame. Both ends of each clamp component are rotatably hinged on both parallel support components respectively. A clamping space exists between the two parallel clamp components. The L-shaped drive component is rotatably hinged on the frame. The L-shaped drive component comprises a contact end and a driving end. The contact end contacts one of the parallel clamp components. When the driving end receives an external force, the contact end generates a pushing force on a corresponding parallel clamp component by leverage. The spring is connected between the frame and one of the parallel clamp components. The spring exerts a preset first resilient force on one of the corresponding parallel clamp components. The clamping space is modified by adjusting the external force to clamp or release a disc. The two-way disc clamping mechanism allows the disc to enter the clamping space from a left side or a right side thereof.  
      A disc changing mechanism is also provided. An exemplary embodiment of a disc changing mechanism, for accessing a disc placed in a disc case, comprises a support stand, a bearing platform, a two-way disc clamping mechanism as described above, and a disc ejection mechanism. The bearing platform is upward and downward movably placed on the support stand. The two-way disc clamping mechanism is leftward and rightward movable and placed on the bearing platform by the frame thereof for clamping or releasing the disc at a first operating location corresponding to the disc case. The disc ejection mechanism comprises two disc ejection levers respectively fixed on a left side and a right side of the bearing platform for pushing the disc from the inside of the disc case to the clamping space of the two-way disc clamping mechanism. When the disc changing mechanism is in retrieval mode, the two-way disc clamping mechanism moves to the corresponding first operating location, the corresponding disc ejection lever pushes the disc from the inside of the disc case to the clamping space of the two-way disc clamping mechanism, and the two-way disc clamping mechanism clamps the disc removing it from the disc case. When the disc changing mechanism is in placement mode, the two-way disc clamping mechanism moves to the corresponding first operating location, moves the clamped disc to the inside of the disc case, and releases the disc.  
      A multiple disc read and write system is also provided. An exemplary embodiment of a multiple disc read and write system, capable of disc changing, comprises a base, two disc cabinets, a read and write mechanism, and a disc changing mechanism as described above. The two disc cabinets are respectively fixed on a left end and a right end of the base. Each disc cabinet comprises a plurality of disc cases stacked vertically for accommodating a plurality of discs horizontally. The read and write mechanism is fixed on the base for reading and writing data on the discs. The disc changing mechanism is fixed on the base by the support stand thereof. The two-way disc clamping mechanism moves to a plurality of first operating locations corresponding to the disc cases to clamp or release the discs. The two-way disc clamping mechanism moves to a second operating location corresponding to the read and write mechanism to clamp or release the discs. 
    
    
     DESCRIPTION OF THE DRAWINGS  
      Two-way disc clamping mechanisms and multiple disc read and write systems can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:  
       FIG. 1  is a 3-D diagram of an embodiment of a two-way disc clamping mechanism.  
       FIG. 2  is a cutaway view of the two-way disc clamping mechanism in  FIG. 1  from the left side.  
       FIG. 3  is a 3-D diagram of an embodiment of a disc changing mechanism.  
       FIG. 4  is a schematic diagram showing the disc changing mechanism in  FIG. 3  accessing a disc in a disc case.  
       FIG. 5  is a 3-D diagram of a return spring.  
       FIG. 6  is a schematic diagram showing a disc ejection mechanism pushing a disc from inside a disc case to a clamping space of the two-way disc clamping mechanism in  FIG. 1 .  
       FIG. 7  is a schematic diagram of an embodiment of a multiple disc read and write system.  
       FIG. 8  is a schematic diagram showing a chassis removed from a housing and a base rotated with an appropriate angle.  
    
    
     DETAILED DESCRIPTION  
       FIG. 1  is a 3-D diagram of an embodiment of a two-way disc clamping mechanism  101 .  FIG. 2  is a cutaway view of the two-way disc clamping mechanism  101  in  FIG. 1  from the left side, as indicated by the arrow  128 . The two-way disc clamping mechanism  101  comprises a frame  111 , parallel first and second support components  112  and  113 , parallel first and second clamp components  116  and  117 , an L-shaped drive component  123 , and a spring  127 . The first support component  112  is rotatably connected to a hinge  114  of the frame  111 , and the second support component  113  is rotatably connected to a hinge  115  of the frame  111 . Two ends of the first clamp component  116  are rotatably connected respectively to a hinge  118  of the first support component  112  and a hinge  119  of the second support component  113 . Similarly, two ends of the second clamp component  117  are rotatably connected respectively to a hinge  120  of the first support component  112  and a hinge  121  of the second support component  113 . The first support component  112 , the second support component  113 , the first clamp component  116 , and the second clamp component  117  comprise a rectangular four-bar linkage. Space between the first and second clamp components  116  and  117  comprises a clamping space  122 . The spring  127  is connected between the frame  111  and the second clamp component  117 . Because an appropriate preset force is exerted to the spring  127 , the spring  127  generates a first resilient force on the second clamp component  117 . As shown in  FIG. 2 , the first resilient force pushes the second clamp component  117  forward, so that the space between the first and second clamp components  116  and  117  is reduced reducing the clamping space  122  to its minimum. The two-way disc clamping mechanism  101  is thus closed and prevents disc insertion. The L-shaped drive component  123  is rotatably connected to a hinge  124  of the frame  111 . The L-shaped drive component  123  comprises a contact end  125  and a driving end  126 . The contact end  125  contacts a protrusion  130  of the first clamp component  116 . The driving end  126  is connected with a power source  102 , such as a motor or an electromagnetic valve, to receive an external force provided thereby. The external force pushes the driving end  126  downwards, so the contact end  125  generates a pushing force on the protrusion  130  by leverage. Thus, the first clamp component  116  is pushed forward, increasing the distance between the first and second clamp components  116  and  117  enlarging the clamping space  122 . The two-way disc clamping mechanism  101  is thus open. The two-way disc clamping mechanism  101  clamps the disc by the first and second clamp components  116  and  117  to tightly contact an upper surface and a lower surface of the disc respectively. The two-way disc clamping mechanism  101  clamps the disc along a vertical direction. Thus, the disc can be inserted when a height of the clamping space  122  is increased to larger than a thickness of the disc. Moreover, a lower surface of the first clamp component  116  and an upper surface of the second clamp component  117  are both covered with a smooth elastic material to protect the disc surface when clamped. The clamping space  122  is adjusted by varying the external force provided by the power source  102 , such as a motor or an electromagnetic valve, to clamp or release the disc. The distance between the first and second clamp components  116  and  117  increases enlarging the clamping space  122  as the external force increases. Thus, the two-way disc clamping mechanism  101  is opened. Conversely, the space between the first and second clamp components  116  and  117  is reduced reducing the clamping space  122  as the external force decreases, so the two-way disc clamping mechanism  101  is closed. Additionally, the two-way disc clamping mechanism  101  allows the disc to enter the clamping space  122  from a left side, as indicated by the arrow  128 , or a right side, as indicated by the arrow  129 .  
       FIG. 3  is a 3-D diagram of an embodiment of a disc changing mechanism  301 .  FIG. 4  is a schematic diagram showing the disc changing mechanism  301  in  FIG. 3  accessing a disc  319  in a disc case  318 .  FIG. 5  is a 3-D diagram of a return spring  320 . The disc changing mechanism  301  comprises a support stand  311 , a bearing platform  312 , the two-way disc clamping mechanism  101 , and a disc ejection mechanism  316 . The bearing platform  312  is placed on the support stand  311  and is able to move freely along an upward-downward direction  313 . The two-way disc clamping mechanism  101  is placed on the bearing platform  312  by the frame  111  thereof and can move freely along a leftward-rightward direction  314 . The disc ejection mechanism  316  comprises two disc ejection levers  317  respectively fixed on a left side and a right side of the bearing platform  312 . Each side of the disc case  318  comprises a return spring  320 , which is a two-way flat spring, as shown in  FIG. 5 . Because an appropriate preset force is exerted to the return spring  320 , the return spring  320  generates a second resilient force on the disc  319 .  
       FIG. 6  is a schematic diagram showing a disc ejection mechanism  316  pushing the disc  319  from inside of the disc case  318  to the clamping space  122  of the two-way disc clamping mechanism  101  in  FIG. 1 . When the disc changing mechanism  301  is in retrieval mode, a driving device (not shown) adjusts the location of the bearing platform  312  vertically and the location of the two-way disc clamping mechanism  101  horizontally, so the two-way disc clamping mechanism  101  is moved to a first operating location  315  corresponding to the disc case  318 . The power source  102 , such as a motor or an electromagnetic valve, exerts external force on the driving end  126  to open the two-way disc clamping mechanism  101 . The disc ejection lever  317  is then driven by a driving device (not shown) to push the disc  319  from the disc case  318  to a first intermediate location (not shown), i.e. the disc  319  is pushed to a pinnacle  321  of the return spring  320 . The second resilient force generated by the return spring  320  further pushes the disc  319  to the clamping space  122  of the two-way disc clamping mechanism  101 . Finally, the power source  102 , such as a motor or an electromagnetic valve, stops generating the external force on the driving end  126  to gradually close the two-way disc clamping mechanism  101 . The two-way disc clamping mechanism  101  thus clamps the disc  319  removing it from the disc case  318 . The dashed lines in  FIG. 6  indicate locations of the disc ejection lever  317   a  and the disc  319   a  after the disc ejection lever  317  pushes the disc  319  from inside the disc case  318  to the clamping space  122  of the two-way disc clamping mechanism  101 .  
      When the disc changing mechanism  301  is in placement mode, a driving device (not shown) adjusts the location of the bearing platform  312  vertically and the location of the two-way disc clamping mechanism  101  horizontally, so the two-way disc clamping mechanism  101  is moved to a first operating location  315  corresponding to the disc case  318 . The two-way disc clamping mechanism  101  moves the clamped disc  319  to a second intermediate location (not shown), i.e. the disc  319  is pushed to the pinnacle  321  of the return spring  320 , and then releases the disc  319 . The second resilient force generated by the return spring  320  further pushes the disc  319  into the disc case  318 . Thus, the disc  319  can be moved between any two disc cases by the disc changing mechanism  301 .  
       FIG. 7  is a schematic diagram of an embodiment of a multiple disc read and write system  701 . The multiple disc read and write system  701  is capable of changing discs and comprises a housing  718 , a chassis  716 , a base  711 , two disc cabinets  712 , a read and write mechanism  715 , and the disc changing mechanism  301 . The housing  718  covers and protects the entire system. The chassis  716  is rotatably fixed to the base  711  and comprises roll wheels  717  for bearing the chassis  716 . The two disc cabinets  712  are respectively fixed on a left end and a right end of the base  711 . Each disc cabinet  712  comprises three disc cases  713  stacked vertically for accommodating discs  714 . Each disc case  713  can accommodate 30 to 50 discs  714 . Each disc case  713  is designed based on a module capable of continuous vertical stacking. Each disc case  713  comprises V-shaped grooves for inserting the discs  714 . The discs  714  slide freely in the V-shaped grooves to a specific location where the discs  714  are securely held thereby. The V-shaped grooves also facilitate disc access by the two-way disc clamping mechanism  101 . Moreover, each side of the disc case  713  comprises the return spring  320 , which is a two-way flat spring, as shown in  FIG. 5 . Because the appropriate preset force is exerted to the return spring  320 , the return spring  320  generates the second resilient force on the discs  714 . The read and write mechanism  715  is fixed on the base  711  for reading and writing data on the discs  714 . The disc changing mechanism  301  is fixed on the base  711  by the support stand  311  thereof. The discs  714  can be moved between any two disc cases  713  by the disc changing mechanism  301 , as described above. Additionally, when the system is in read and write mode, the two-way disc clamping mechanism  101  moves to a second operating location (not shown) corresponding to the read and write mechanism  715  to clamp or release the discs  714 . Therefore, the read and write mechanism  715  can read or write data on the discs  714 .  
       FIG. 8  is a schematic diagram showing the chassis  716  removed out of the housing  718  and the base  711  rotated to an appropriate angle  719 . When a large amount of disc access is desired, the chassis  716  with the entire system thereon is removed from the housing  718 , and the base  711  is rotated by the appropriate angle  719  to facilitate disc access by hand.  
      In some embodiments of the multiple disc read and write system, the two-way disc clamping mechanism utilizes a rectangular four-bar linkage to clamp the rim of the disc to stably move the disc to the read and write mechanism or between two disc cases. Compared with the conventional semicircular disc clamper, the two-way disc clamping mechanism is more compact and allows two-way insertion of the disc, thus reducing space required by the entire system. Additionally, each side of the disc case comprises a return spring, which is a two-way flat spring. In retrieval or placement mode, the second resilient force of the return spring pushes the disc to the desired location if the disc has previously been pushed to the pinnacle of the return spring, thus potentially reducing disc motion and motor operation.  
      While the invention has been described by way of example and in terms of several embodiments, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art) . Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.