Abstract:
There is provided an optical recording media cartridge, which is provided with a case that accommodates the optical recording media and that has an opening, and a shutter that is attached to the case and that is movable between a first position at which the shutter covers the opening and a second position. The optical recording media cartridge is further provided with a shutter lock mechanism that locks the shutter while the shutter is positioned at the first position, and a shutter release mechanism that releases the shutter locked by the shutter lock mechanism by utilizing a magnetic force exerted thereon.

Description:
BACKGROUND OF THE INVENTION 
   The present invention relates to a cartridge for protecting an optical recording media accommodated therein. 
   Generally, the cartridge for protecting the optical recording media such as an MO (magneto-optic disc) has an opening from which the optical recording media is exposed and a shutter which covers the opening while the cartridge is detached from an optical disc drive. Since the opening is covered by the shutter, the MO in the cartridge can be protected against dust. 
   Further, the cartridge has a shutter lock mechanism which keeps the shutter closed while the cartridge is detached from the optical disc drive and a shutter release mechanism which release the shutter when the cartridge is inserted into the optical disc drive. 
     FIG. 9  shows a certain type of a conventional known cartridge  101  for a magneto-optic disc  109 . As shown in  FIG. 9 , the cartridge  101  has a case  102 , a shutter  103 , a reception member  104  attached to the shutter  103  by screws, a lock arm  105  rotatably attached to the case  102 , a torsion spring  107 , and the magneto-optic disc  109  accommodated in the case  102 . The case  102  has an opening  102   a  from which the disc  109  is exposed while the cartridge  101  is inserted in an optical disc drive (not shown). The shutter  103  is slidably attached to the case  102  and covers the opening  102   a  while the cartridge  101  is not used, i.e., while the cartridge is detached from the optical disc drive. 
   While the cartridge  101  is attached to the optical disc drive, a head provided in the optical disc drive is driven to record/reproduce information to/from the magneto-optic disc  109  through the opening  102   a.    
   In a situation shown in  FIG. 9 , i.e., while the cartridge  101  is not used, the shutter  103  is locked by engagement of the lock arm  105  and the reception member  104 . 
   The lock arm  105  has an arm portion  105   a , a hook portion  105   b  provided at one end of the arm portion  105   a , and a hole  105   c  formed on the other end of the arm portion  105   a . As shown in  FIG. 9 , a shaft  102   b  is formed on an inside wall of the case  102 . The lock arm  105  is rotatably attached to the shaft  102   b  at the hole  105   c  formed on the other end of the arm portion  105   a.    
   The torsion spring  107  is attached to a shaft  102   c  formed on the inside wall of the case  102 . One end of the torsion spring  107  contacts with the arm portion  105   a , and the other end of the torsion spring  107  contacts with an inside wall of the case  102 . Since the torsion spring  107  pushes the lock arm  105  upward on the  FIG. 9 , the hook portion  105   b  engages with the reception member  104 . Consequently, the shutter  103  is kept closed while the cartridge  101  is not used. 
   Although the above described configuration of the cartridge  101  enables the shutter  103  to be kept closed while the cartridge  101  is detached from the optical disc drive, the conventional cartridge  101  has a problem that the shutter  103  is relatively easily opened by pushing the lock arm  105  using a pin through an opening  102   e . The opening  102   e  is essential to mechanically release the shutter  103  when the cartridge  101  is attached to the optical disc drive. 
   SUMMARY OF THE INVENTION 
   The present invention is advantageous in that it provides an optical recording media cartridge which can reliably lock a shutter attached thereon while the optical recording media cartridge is detached from an optical recording media drive. 
   According to an aspect of the present invention, there is provided an optical recording media cartridge for protecting an optical recording media. The optical recording media cartridge is provided with a case that accommodates the optical recording media and that has an opening from which the optical recording media is exposed, and a shutter that is attached to the case and that is movable between a first position at which the shutter covers the opening and a second position. The optical recording media cartridge is further provided with a shutter lock mechanism that locks the shutter while the shutter is positioned at the first position, and a shutter release mechanism that releases the shutter locked by the shutter lock mechanism by utilizing a magnetic force exerted thereon. 
   Since a locked state of the shutter is released when the magnetic force is exerted on the shutter release mechanism, it is prevented that the shutter is accidentally opened, for example, by using a pin. 
   Optionally, the shutter lock mechanism and the shutter release mechanism may be mounted inside the case, and the optical recording media cartridge may substantially completely cover the optical recording media, the shutter lock mechanism and the shutter release mechanism when the shutter is positioned at the first position. 
   Still optionally, at least a portion of the optical recording media may be exposed when the shutter is positioned at the second position. 
   In a particular case, the shutter lock mechanism may include a lock member attached to the shutter. In this case, the lock member locks the shutter while the shutter is positioned at the first position. 
   Optionally, the lock member may have a hook that engages with a recess formed on the case while the shutter is positioned at the first position. In this case, the shutter is locked by engagement of the hook and the recess. 
   In a particular case, the shutter release mechanism may include a magnet attached to the lock member, and the engagement of the hook of the lock member and the recess of the case is released by the magnetic force exerted on the magnet attached to the lock member. 
   In a particular case, the magnetic force exerted on the magnet may be an attractive force. 
   In a particular case, the attractive force may act on the magnet when an external magnet approaches the magnet from outside the optical recording media cartridge. 
   In a particular case, the attractive force may act on the magnet when an external magnetic material approaches the magnet from outside the optical recording media cartridge. 
   In a particular case, the magnetic force exerted on the magnet may be a repulsive force. 
   In a particular case, the repulsive force may act on the magnet when an external magnet approaches the magnet from outside the optical recording media cartridge. 
   In a particular case, the shutter release mechanism may include a magnetic material attached to the lock member, and the engagement of the hook of the lock member and the recess of the case is released by the magnetic force exerted on the magnetic material attached to the lock member. 
   In a particular case, the magnetic force exerted on the magnetic material may be an attractive force. 
   In a particular case, the attractive force may act on the magnetic material when an external magnet approaches the magnetic material from outside the optical recording media cartridge. 
   In a particular case, the shutter lock mechanism may include a lock member attached to the case. In this case, the lock member locks the shutter while the shutter is positioned at the first position. 
   Optionally, the lock member may have a hook that engages with a recess formed on the shutter while the shutter is positioned at the first position. In this case, the shutter is locked by engagement of the hook and the recess. 
   In a particular case, the shutter release mechanism may include a magnet attached to the lock member, and the engagement of the hook of the lock member and the recess of the shutter is released by the magnetic force exerted on the magnet attached to the lock member. 
   In a particular case, the shutter release mechanism may include a magnetic material attached to the lock member, and the engagement of the hook of the lock member and the recess of the shutter is released by the magnetic force exerted on the magnetic material attached to the lock member. 
   In a particular case, the magnetic force exerted on the shutter release mechanism may be an attractive force. 
   In a particular case, the magnetic force exerted on the shutter release mechanism may be a repulsive force. 
   Optionally, the optical recording media may include an optical disc. 
   According to another aspect of the present invention, there is provided an optical recording media drive for recording/reproducing information to/from an optical recording media accommodated in a cartridge. The cartridge includes a case that accommodates the optical recording media and that has an opening from which the optical recording media is exposed, a shutter that is attached to the case and that is movable between a first position at which the shutter covers the opening and a second position, a shutter lock mechanism that locks the shutter while the shutter is positioned at the first position, and a shutter release mechanism that releases the shutter locked by the shutter lock mechanism by utilizing a magnetic force exerted thereon. The optical recording media drive includes a body, a magnet that exerts the magnetic force when the cartridge is attached to the optical recording media drive, and a shutter open member that moves the shutter of the cartridge from the first position to the second position when the cartridge is attached to the optical recording media drive. 
   Since a locked state of the shutter is released when the magnetic force is exerted on the shutter release mechanism, it is prevented that the shutter is accidentally opened, for example, by using a pin. 
   Optionally, the shutter open member may include an arm member rotatably attached to the body, the arm member having an end portion which engages with a notch formed on the cartridge. The end portion of the arm member moves when the cartridge is attached to the optical recording media drive so as to move the shutter of the cartridge from the first position to the second position. The magnet is attached to the end portion of the arm member. 
   Still optionally, the body may have a slot to which the cartridge is attached. 
   According to another aspect of the present invention, there is provided an optical recording media drive for recording/reproducing information to/from an optical recording media accommodated in a cartridge. The cartridge includes a case that accommodates the optical recording media and that has an opening from which the optical recording media is exposed, a shutter that is attached to the case and that is movable between a first position at which the shutter covers the opening and a second position, a shutter lock mechanism that locks the shutter while the shutter is positioned at the first position, and a shutter release mechanism that releases the shutter locked by the shutter lock mechanism by utilizing a magnetic force exerted thereon. The optical recording media drive includes a body, a magnetic material that exerts the magnetic force when the cartridge is attached to the optical recording media drive, and a shutter open member that moves the shutter of the cartridge from the first position to the second position when the cartridge is attached to the optical recording media drive. 
   Since a locked state of the shutter is released when the magnetic force is exerted on the shutter release mechanism, it is prevented that the shutter is accidentally opened, for example, by using a pin. 
   According to another aspect of the present invention, there is provided a system having an optical recording media cartridge and an optical recording media drive for recording/reproducing information to/from an optical recording media accommodated in the optical recording media cartridge. The optical recording media cartridge includes a case that accommodates the optical recording media and that has an opening from which the optical recording media is exposed, a shutter that is attached to the case and that is movable between a first position at which the shutter covers the opening and a second position, a shutter lock mechanism that locks the shutter while the shutter is positioned at the first position, and a shutter release mechanism that releases the shutter locked by the shutter lock mechanism by utilizing a magnetic force exerted thereon. The optical recording media drive includes a body, a magnet that exerts the magnetic force when the cartridge is attached to the optical recording media drive, and a shutter open member that moves the shutter of the optical recording media cartridge from the first position to the second position when the optical recording media cartridge is attached to the optical recording media drive. 
   Since a locked state of the shutter is released when the magnetic force is exerted on the shutter release mechanism, it is prevented that the shutter is accidentally opened, for example, by using a pin. 
   According to another aspect of the present invention, there is provided a system having an optical recording media cartridge and an optical recording media drive for recording/reproducing information to/from an optical recording media accommodated in the optical recording media cartridge. The optical recording media cartridge includes a case that accommodates the optical recording media and that has an opening from which the optical recording media is exposed, a shutter that is attached to the case and that is movable between a first position at which the shutter covers the opening and a second position, a shutter lock mechanism that locks the shutter while the shutter is positioned at the first position, and a shutter release mechanism that releases the shutter locked by the shutter lock mechanism by utilizing a magnetic force exerted thereon. The optical recording media drive includes a body, a magnetic material that exerts the magnetic force when the cartridge is attached to the optical recording media drive, and a shutter open member that moves the shutter of the optical recording media cartridge from the first position to the second position when the optical recording media cartridge is attached to the optical recording media drive. 
   Since a locked state of the shutter is released when the magnetic force is exerted on the shutter release mechanism, it is prevented that the shutter is accidentally opened, for example, by using a pin. 

   
     BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS 
       FIG. 1  shows an optical disc drive system according to a first embodiment of the present invention; 
       FIG. 2  shows the optical disc drive system in which an optical disc cartridge is fully inserted into a slot formed on an optical disc drive; 
       FIG. 3  is an enlarged view of the optical disc cartridge illustrating a situation where a magnet of a shutter open arm does not engage with a notch of a shutter; 
       FIG. 4  is an enlarged view of the optical disc cartridge illustrating a situation where the magnet of the shutter open arm engages with the notch of the shutter; 
       FIG. 5  shows an optical disc drive system according to a second embodiment of the present invention; 
       FIG. 6  shows the optical disc drive system, according to the second embodiment, in which an optical disc cartridge is fully inserted into a slot formed on an optical disc drive; 
       FIG. 7  is an enlarged view of the optical disc cartridge according to the second embodiment illustrating a situation where a magnet of a shutter open arm does not engage with a notch of a shutter; 
       FIG. 8  is an enlarged view of the optical disc cartridge according to the second embodiment illustrating a situation where the magnet of the shutter open arm engages with the notch of the shutter; and 
       FIG. 9  shows a certain type of a conventional cartridge for a magneto-optic disc. 
   

   DETAILED DESCRIPTION OF THE EMBODIMENTS 
   Hereinafter, embodiments according to the invention are described with reference to the accompanying drawings. 
   First Embodiment 
   Each of  FIGS. 1 and 2  shows an optical disc drive system  1  according to a first embodiment of the present invention. The optical disc drive system  1  has an optical disc cartridge  11  and an optical disc drive  21 . 
   In the optical disc drive  21 , various components such as an optical pick-up, a driving mechanism, and a signal processing system are accommodated. Since these components are well known in the art, detailed descriptions thereof are omitted. 
   As shown in  FIG. 1 , a body  21   a  of the optical disc drive  21  has a slot  22  in which the optical disc cartridge  11  is inserted. The body  21   a  further has a shutter open arm  23  having one end at which a hole  23   b  is formed and having the other end  23   d  to which a magnet  23   a  is attached. 
   The hole  23   b  of the shutter open arm  23  is attached to a shaft  26  formed on a bottom surface of the slot  22  so that the shutter open arm  23  is rotatable about the shaft  26 . 
   A torsion spring  24  is also attached to the shaft  26 . As shown in  FIG. 1 , one end of the torsion spring  24  contacts a side wall  22   a  of the slot  22 , and the other end of the torsion spring  24  is fixed to an arm portion  23   c  of the shutter open arm  23 . With this structure, the torsion spring  24  exerts a force on the shutter open arm  23  to turn the shutter open arm  23  counterclockwise. 
   A stopper  25  is attached to the bottom surface of the slot  22  so as to limit a range of a swing motion of the shutter open arm  23 . Therefore, the shutter open arm  23  is held at an initial position shown in FIG.  1 . 
   The optical disc cartridge  11  has a case  12 , a shutter  13  slidably attached to the case  12 , and an optical disc  19  accommodated in the case  12 . The case  12  has an opening  12   a  from which the optical disc  19  is exposed while the optical disc cartridge  11  is inserted into the slot  22 . The shutter  13  is slidable in a horizontal direction in FIG.  1 . 
   The shutter  13  covers the opening  12   a  while the optical disc cartridge  11  is not used so as to prevent the optical disc  19  from being exposed. As described in detail below, the optical disc cartridge  11  has a lock mechanism which locks the shutter  13  while the optical disc cartridge  11  is not used. The shutter  13  has a notch  13   a  which engages with the magnet  23   a  attached to the shutter open arm  23 . 
   When the optical disc cartridge  11  is inserted into the slot  22 , i.e., when the optical disc cartridge  11  is moved from a position shown in  FIG. 1  to a position shown in  FIG. 2 , the magnet  23   a  engages with the notch  13   a  of the shutter  13  and releases a locked state of the shutter  13  so that the shutter  13  becomes slidable on the case  12 . As the optical disc cartridge  11  moves toward the side wall  22   a  of the slot  22 , the shutter open arm  23  rotates clockwise and makes the shutter  13  slide to the left on FIG.  1 . 
   As shown in  FIG. 2 , when a tip portion of the optical disc cartridge  11  contacts stoppers  30  and  30  formed on the slot  22 , the shutter  13  is fully opened by the shutter open arm  23 . In a situation shown in  FIG. 2 , the optical disc cartridge  11  is fully inserted into the slot  22 . The shutter open arm  23  is now substantially parallel to the side wall  22   a  of the slot  22 . 
   Next, the lock mechanism for locking the shutter  13  while the optical disc cartridge  11  is detached from the slot  22 , and a shutter release mechanism which releases the locked state of the shutter  13  will be described in detail. 
     FIGS. 3 and 4  are enlarged views of an upper portion of the optical disc cartridge  11 .  FIG. 3  shows a situation where the magnet  23   a  of the shutter open arm  23  does not engage with the notch  13   a  of the shutter  13 .  FIG. 4  shows a situation where the magnet  23   a  of the shutter open arm  23  engages with the notch  13   a  of the shutter  13 . 
   As shown in  FIG. 3 , the optical disc cartridge  11  has a spacer  17  which is mounted inside the case  12  and which is fixed to the shutter  13 . The spacer  17  is guided by rails (not shown) formed on an inside surface of the case  12  and is slidable in a horizontal direction on FIG.  3 . 
   The optical disc cartridge  11  includes a lock arm  14  and a torsion spring  16 . The lock arm  14  has a shaft  14   c , a hook  14   a  formed at one end thereof, and a magnet  14   b  attached to the other end thereof. The shaft  14   c  of the lock arm  14  is inserted into a hole  13   b  (see  FIGS. 1 and 2 ) formed on the shutter  13  with the torsion spring  16  being hooked to the shaft  14   c.    
   As shown in  FIG. 3 , one end of the torsion spring  16  contacts with an inside surface of the shutter  13 , and the other end of the torsion spring  16  is fixed to the lock arm  14  at a position between the shaft  14   c  and the hook  14   a . With this structure, the torsion spring  16  exerts a force on the lock arm  14  to turn the lock arm  14  counterclockwise. 
   Since the hook  14   a  of the lock arm  14  is pushed downward in the  FIG. 3 , the hook  14   a  firmly engages with a recess  12   b  formed on the case  12  while the shutter  13  is positioned at a position shown in  FIG. 3 , i.e., while the shutter  13  completely covers the opening  12   a . Thus, the shutter  13  is locked by engagement of the hook  14   a  and the recess  12   b.    
   The magnet  14   b  attached to the other end of the lock arm  14  is adjacent to the notch  13   a . In addition, a surface of the magnet  14   b  nearest to the notch  13   a , and a surface of the magnet  23   a  nearest to the notch  13   a  have the same magnetic poles. Therefore, when the magnet  23   a  approaches the notch  13   a , repulsive forces are exerted on the magnet  23   a  and the magnet  14   b.    
   It should be noted that since the lock arm  14  is completely covered by the shutter  13  and the case  12  (see FIGS.  3  and  4 ), the lock arm  14  can not be moved by using, for example, a pin. 
   When the magnet  23   a  contacts with the notch  13   a  of the optical disc cartridge  11 , the lock arm  14  is rotated clockwise by the repulsive force exerted on the magnet  14   b . Consequently, the hook  14   a  is disengaged from the recess  12   b  as shown in  FIG. 4 , which releases the locked state of the shutter  13  and makes the shutter  13  slidable on the case  12 . As the optical disc cartridge  11  is inserted into the slot  22 , the shutter open arm  23  slides the shutter  13 . Finally, the shutter open arm  23  brings the shutter  13  to the position shown in FIG.  2 . 
   When the optical disc cartridge  11  is pulled out, the shutter open arm  23  slides the shutter  13  right and brings the shutter  13  to the position shown in  FIG. 1  because the torsion spring  26  exerts the force on the shutter open arm  23  to turn the shutter open arm  23  counterclockwise. 
   As described above, according to the first embodiment of the present invention, the shutter: 13  is locked reliably while the shutter covers the openings  12   a . The shutter  13  cannot be opened by using, for example, a pin. The locked state of the shutter  13  is released only when the optical disc cartridge  11  is inserted in the slot  22  of the optical disc drive  21 . Therefore, the optical disc  19  is protected reliably. 
   Second Embodiment 
   A second embodiment of the present invention will be described with reference to  FIGS. 5-8 . 
     FIGS. 5 and 6  show an optical disc drive system  201  according to the second embodiment of the present invention. The optical disc drive system  201  has an optical disc cartridge  211  and an optical disc drive  21 . The feature of the second embodiment is that a release mechanism for releasing a shutter  213  is actuated by an attractive force exerted on a lock arm  214  (see FIG.  7 ). Therefore, an explanation of the second embodiment will focus on a lock mechanism and the release mechanism for the shutter  213 . 
   In each of  FIGS. 5-8 , to elements which are similar to those in  FIGS. 1-4 , the same reference numbers are assigned, and the detailed description thereof will not be repeated. 
     FIG. 5  shows a situation where the optical disc cartridge  211  is not fully inserted into the slot  22  of the optical disc drive  21 .  FIG. 6  shows a situation where the optical disc cartridge  211  is fully inserted into the slot  22  of the optical disc drive  21 . 
   Each of  FIGS. 7 and 8  is an enlarged view of an upper portion of the optical disc cartridge  211 . As shown in  FIG. 7 , the optical disc cartridge  211  has the spacer  17  which is mounted inside the case  212  and which is fixed to the shutter  213 . The spacer  17  is guided by rails (not shown) formed on an inside surface of the case  212  and is slidable in a horizontal direction on FIG.  7 . 
   The optical disc cartridge  211  has the lock arm  214  and a torsion spring  216 . The lock arm  214  has a shaft  214   c  and a hook  214   a  formed at one end thereof. The shaft  214   c  of the lock arm  214  is inserted into the hole  13   b  (see  FIGS. 5 and 6 ) formed on the shutter  213  with the torsion spring  216  being hooked to the shaft  214   c.    
   One end of the torsion spring  216  contacts with an inside surface of the shutter  213 , and the other end of the torsion spring  216  is fixed to the lock arm  214  at a position between the shaft  214   c  and the other end  214   d  of the lock arm  214 . With this structure, the torsion spring  216  exerts a force on the lock arm  214  to turn the lock arm  214  clockwise. 
   Since the hook  214   a  of the lock arm  214  is pushed downward in  FIG. 7  by the torsion spring  216 , the hook  214   a  firmly engages with a recess  212   b  formed on the case  212  while the shutter  213  is positioned at a position shown in  FIG. 7 , i.e., while the shutter  213  completely covers the opening  212   a . Thus, the shutter  213  is locked by engagement of the hook  214   a  and the recess  212   b.    
   It should be noted that the lock arm  214  is completely covered by the shutter  213  and the case  212  (see FIGS.  7  and  8 ), the lock arm  214  can not be moved by using, for example, a pin. 
   To the one end of the lock arm  214 , a magnetic material  214   b  is also attached. Accordingly, as shown in  FIG. 8 , when the magnet  23   a  approaches the notch  213   a  of the shutter  213 , the magnetic material  214   b  (i.e., the one end of the lock arm  214 ) is attracted by the magnet  23   a  and therefore the lock arm  214  is rotated counterclockwise by the attractive force exerted on the magnetic material  214   b . Consequently, the hook  214   a  is disengaged from the recess  212   b , which releases the locked state of the shutter  213  and makes the shutter  213  slidable on the case  212 . 
   As the optical disc cartridge  211  is inserted to the slot  22 , the shutter open arm  23  slides the shutter  213 . Finally, the shutter open arm  23  brings the shutter  213  to the position shown in FIG.  6 . 
   When the optical disc cartridge  211  is pulled out, the shutter open arm  23  slides the shutter  213  right and brings the shutter  213  to the position shown in  FIG. 5  because the torsion spring  26  exerts the force on the shutter open arm  23  to turn the shutter open arm  23  counterclockwise. 
   Although the present invention has been described in considerable detail with reference to certain preferred embodiments thereof, other embodiments are possible. 
   For example, in the described embodiments, the shutter lock mechanism including the lock arm ( 14 , 214 ) and the torsion spring ( 16 , 216 ) is attached to the shutter ( 13 , 213 ), the shutter lock mechanism may be alternatively attached to the case ( 12 , 212 ) of the optical disc cartridge ( 11 , 211 ) so that the hook ( 14   a , 214   a ) of the lock arm engages with a recess form on the shutter. 
   Although, in the second embodiment, the magnetic material  214   a  is used to exert the attractive force on the lock arm  214 , a magnet may be alternatively attached to the lock arm  214  to exert an attractive force on the lock arm  214 . In this case, a magnetic pole of a notch  213   a  side surface of the magnet attached to the lock arm is opposite to a magnetic pole of a notch  213   a  side surface of the magnet  23   a  attached to the shutter open arm  23 . 
   If the magnet is attached to the lock arm  214 , the magnet  23   a  attached to the shutter open arm  23  may be replaced with a magnetic material to exert attractive forces between the magnetic material attached to the shutter open arm  23  and the magnet attached to the lock arm  214 . 
   As described above, in the case of the second embodiment, the magnetic material  214   b  attached to the lock arm  214  can be replaced with a magnet. However, to use the magnetic material  214   b  is advantageous in that a distance at which attractive forces start to exert on the lock arm and the shutter open arm can be shorten in comparison with the case where the magnet is attached to the lock arm  214 . 
   The present disclosure relates to the subject matters contained in Japanese Patent Applications No. 2002-251679, filed on Aug. 29, 2002, and No. 2002-251680, filed on Aug. 29, 2002, which are expressly incorporated herein by reference in their entireties.