Patent Publication Number: US-2007124744-A1

Title: Shutter opening/closing apparatus and information reproducing apparatus

Description:
FIELD OF THE INVENTION  
      The present invention relates to a technical field of a recording medium driving apparatus and an information reproducing apparatus provided with a shutter opening/closing mechanism provided for a cartridge, in which an information recording medium such as optical disk is accommodated, and configured to open and close a shutter which protects an optical disk or like.  
     BACKGROUND ART  
      A shutter opening/closing mechanism of a cartridge in which an information recording medium is accommodated exits conventionally. Such conventional shutter opening/closing mechanism will be explained hereunder with reference to FIGS.  1  to  4 .  
       FIG. 1  shows an information reproducing apparatus  30  which performs an information recording and/or reproducing operation with respect to an information recording medium. A shutter opening/closing mechanism for such information reproducing apparatus is automatically opened or closed by the loading or unloading of a cartridge  35 .  
      The information reproducing apparatus  30  has a case  31  having a front surface in which a cartridge insertion hole  31   a , through which the cartridge  35  is loaded or unloaded, is formed. A shutter is provided in the cartridge  35 , and a shutter opener  32  for opening or closing a shutter in accordance with a relative motion to the information reproducing apparatus  30  at the time of loading the cartridge to or unloading it from the information reproducing apparatus is formed to an inner wall section of one of side portions of the case  31 . The shutter is opened by rotating a wheel, not shown, in the cartridge  35  in accordance with a relative motion with respect to the shutter opener  32  at the time of loading the cartridge.  
      As shown in  FIG. 2 , the shutter opener  32  is provided with a rack  33  and protruded portions  34 ,  34  at both sides in the cartridge moving direction. The protruded portions  34  are always urged by a spring, not shown, toward a housing ( 36 ) side of the cartridge  35  as shown in  FIG. 3 .  
      With reference to  FIG. 3 , the operation of respective portions of the information reproducing apparatus  30  at the time of loading the cartridge  35  therein will be described hereunder.  
       FIG. 3  includes views (a) to (d), from the left side, which are sectional views showing cartridge loading sequence in this order, in which the cartridge  35 , is loaded from the lower side to the upper side. According to this loading operation of the cartridge  35  with respect to the shutter opener  32 , the shutter in the cartridge  35  is opened.  
      As shown in  FIG. 3 ( a ), when the cartridge  35  is loaded, one of the protruded portions  34  of the shutter opener  32  is engaged with one of two recessed portions  38  formed to an outer peripheral surface of a wheel  37 , and the wheel  37  is rotated in a counter-clockwise direction in  FIG. 3 ( a ).  
      Next, as shown in FIGS.  3 ( b ) and  3 ( c ), when the cartridge  35  is further moved, the wheel  37  is accordingly rotated, and the rack  33  formed to the shutter opener  32  is engaged with a rack  39  formed between the recessed portions  38  of the wheel  37  to thereby further rotate the wheel  37 .  
      Then, as shown in  FIG. 3 ( d ), the other one protruded portion  34  of the shutter opener  32  is engaged with the other one recessed portion  39  of the wheel  37 , and the other one protruded portion  34  is moved to the central portion of the cartridge  35 . According to these series of motions, the shutter opening operation has been completed.  
      On the other hand, at the time of unloading the cartridge  35 , operations reverse to those mentioned above will be performed to close the shutter opener  32 .  
      The information reproducing apparatus provided with the shutter opening/closing mechanism, which is opened at the cartridge loading time and closed at the cartridge unloading time, is disclosed in the following Patent Publications 1 and 2.  
      Patent Publication 1: Japanese Patent Unexamined Application (Laid-open) Publication No. 2003-109282  
      Patent Publication 2: Japanese Patent Unexamined Application (Laid-open) Publication No. 2003-115157  
     DISCLOSURE OF THE INVENTION  
     Problems to be Solved by the Invention  
      However, such conventional apparatus as mentioned above provides a problem such that the protruded portion  34  of the shutter opener  32  collides with the housing  36  of the cartridge  35  and strikes up the protruded portion  34 , which will generate an abnormal noise.  
      In addition, in a case where the cartridge  35  is largely shifted in its position because of play or like, the movement of the cartridge becomes impossible when the protruded portion  34  collides with the housing  36 , and hence, the mechanism for loading or unloading the cartridge may be entirely locked, also providing a problem.  
      Furthermore, at the cartridge loading or unloading time, since the protruded portion  34  always urges the side wall of the cartridge  35 , there is a fear of unstable loading or unloading of the cartridge  35 .  
      An object of the present invention is therefore to substantially eliminate defects or drawbacks encountered in the prior art mentioned above and to provide a shutter opening/closing mechanism capable of automatically opening or closing a shutter in accordance with the loading or unloading of a cartridge and being free from generation of abnormal noise and backlash without giving any influence to the cartridge loading or unloading operation.  
     Means for Solving the Problem  
      In order to solve the above problem, a shutter opening/closing apparatus of claim  1  comprises a follower member ( 18 ) configured to be engaged, at an opening ( 11 ) of a cartridge ( 10 ), with a portion of a drive member ( 13 ) driven in the cartridge ( 10 ) for opening or closing a shutter ( 15 ) provided for the cartridge, and a cam mechanism ( 7 ,  7   a ) limiting a movement of the follower member ( 18 ) so as to avoid a contact of the follower member ( 18 ) to the opening of the cartridge ( 10 ) at a time when the engagement between the follower member ( 18 ) and the portion of the drive member ( 13 ) is released.  
      A shutter opening/closing apparatus of claim  2  comprises a follower member ( 18 ) configured to be engaged, at an opening ( 11 ) of a cartridge ( 10 ), with a portion of a drive member ( 13 ) driven in the cartridge ( 10 ) for opening or closing a shutter ( 15 ) provided for the cartridge, and a cam mechanism ( 7 ,  7   a ) limiting a movement of the follower member ( 18 ) at a time when the cartridge ( 10 ) is loaded and disposed between the follower member ( 18 ) and the cartridge ( 10 ) at a position at which the follower member ( 18 ) does not engage with the portion of the drive member ( 13 ).  
      Further, in the present invention, the shutter opening/closing apparatus may further include urging means ( 17 ) for urging the follower member toward the cartridge. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      [ FIG. 1 ] is a perspective view showing an information reproducing apparatus and a cartridge having conventional structures.  
      [ FIG. 2 ] shows a perspective view of a shutter opener of conventional structure.  
      [ FIG. 3 ] includes (a) to (d) representing a series of shutter opening or closing operation according to the conventional structure.  
      [ FIG. 4 ] includes (a) and (b) representing an operation of the shutter opening or closing operation of at an essential portion of the cartridge in an enlarged scale.  
      [ FIG. 5 ] is a developed perspective view of a cartridge according to one embodiment of the present invention.  
      [ FIG. 6 ] is an illustrated perspective view of an information reproducing apparatus according to one embodiment of the present invention.  
      [ FIG. 7 ] includes (a) to (d) representing a series of shutter opening or closing operation of the shutter opening/closing mechanism according to one embodiment of the present invention.  
      [ FIG. 8 ] shows an operation of one example of a follower pin.  
      [ FIG. 9 ] shows one example in which the follower pin of  FIG. 8  is applied to a conventional structure.  
      [ FIG. 10 ] shows another one example in which the follower pin in  FIG. 8  is applied to a conventional structure.  
      [ FIG. 11 ] is an illustrated perspective view showing a relationship between the follower pin and the cartridge when an arm is applied for a plate spring. 
    
    
     REFERENCE NUMERALS  
       2 —information reproducing apparatus,  7 ,  7   a  —cam,  10 —cartridge,  11 —opening,  13 —wheel,  15 —shutter,  17 —plate spring,  18 —follower pin.  
     BEST MODE FOR EMBODYING THE INVENTION  
      Hereunder, a best mode of a preferred embodiment of the present invention will be described in detail with reference to FIGS.  5  to  10 .  
      Further, it is to be noted that the mode of embodiment described hereunder is an embodiment in which the present invention is applied to an information reproducing apparatus such as optical disk player. Further, in the present invention, although the “information reproducing apparatus” is explained as one example, the present invention is not limited to such apparatus as far as it includes a shutter opening/closing mechanism described herein later. That is, the present invention is not limited to an information reproducing apparatus which reproduces an information and is applicable to an information recording apparatus which records an information and an information recording/reproducing apparatus provided with information recording and reproducing functions.  
      Such information reproducing apparatus is one for performing reproduction of the information such as image, voice and the like while rotating an optical disk accommodated in a cartridge  10 , mentioned herein later, by a rotating and driving unit such as turn table and moving an optical pickup in a radial direction with respect to the optical disk. It is further noted that the “information reproducing apparatus” of the present invention includes an information recording/reproducing apparatus having an information recording function, which can record the information to the optical disk, in addition to such information reproducing function as mentioned above.  
      Furthermore, the optical disk in this case may include CD-ROM (Compact Disc-Read Only Memory), CD-DA (CD Digital Audio), CD-R (CD-Recordable), CD-RW (CD-Re Recordable), Video-CD, CD-G (CD-Extended Graphics), DVD-ROM (Digital Versatile Disc-ROM), DVD-Video, DVD-Audio, DVD-R, DVD-RW, DVD-RAM, Blue-ray Disc and the like.  
      First, with reference to  FIG. 5 , the structure of the cartridge itself will be described.  
      As shown in  FIG. 5 , the cartridge  10  according to the present invention includes a cartridge body  10   a  having an opening opened at its side surface, which will be described herein later. The cartridge body  10   a  is composed of a upper half cartridge body, not shown, and a lower half cartridge body  10   b.    
      Inside the cartridge body  10   a , there is provided a wheel  13  to be rotatable therein, and a portion of the wheel  13  in the circumferential direction is exposed outward from the cartridge body  10   a . This wheel  13  is one example of a drive or driving member of the present invention.  
      The lower cartridge body  10   b  is provided with a predetermined opening  10   c  in the radial direction for the access of a pickup element of the information reproducing apparatus for loading and unloading the cartridge  10  to the optical disk  12 . The wheel  13  is equipped with a shutter  15  through a connection member  14 . In addition, the wheel  13  is also provided with a predetermined opening  13   d  in the radial direction for the access of the pickup element of the information reproducing apparatus to the optical disk  12 . The optical disk  12  is mounted to the upper portion of the wheel  13 .  
      The shutter  15  is cooperated with the rotation of the wheel  13  and is opened or closed through the connection member  14 . At a portion in the circumferential direction of the wheel  13 , there is formed a rack  13   b  which is meshed with a rack  16  which will be mentioned herein later. Further, recessed portions  13   c ,  13   c  to be engaged with a follower or driven pin are formed at portions near both ends of the rack  13   b . This follower pin is an example of a “follower member” of the present invention and the recessed portion  13   c  is a portion of a “drive member” of the present invention.  
      That is, in the described embodiment, although the rack, the follower pin, the recessed portion, and so on prescribe the engaging condition between the information reproducing apparatus and the cartridge, the present invention is not limited to these arrangements as far as the like functions are attainable.  
      The cartridge  10  is loaded into or unloaded from an opening, through a tray.  5 , of the information reproducing apparatus as will be mentioned herein later. The cartridge  10  is accordingly moved relatively with respect to the rack, the follower pin and the like disposed inside the case.  
      The information reproducing apparatus of the present invention will be described hereunder with reference to FIGS.  6  to  10 .  
       FIG. 6  shows a structure of the information reproducing apparatus, and this information reproducing apparatus  2  is provided with a case  2   a  having a flat box-shaped structure. The case  2   a  is formed, in its front surface, with an opening  4  in form of slit extending horizontally through which the cartridge  10  including an optical disk passes at the cartridge loading or unloading time.  
      Inside the case  2   a , the tray  5  is arranged to be capable of being drawn into or drawn out of the case  2   a  through the opening  4 . The tray  5  can be drawn out to a position at which the cartridge  10  is placed thereon and drawn into the case  2   a  to a position at which recording or reproducing operation can be performed by means of optical pickup element.  
      A drive unit, not shown, is connected to the tray  5  and driving means such as motor is mounted to this drive unit. These drive unit and driving means are accommodated in the case  2   a . The tray  5  is hence drawn into or out of the case  2   a  by the operation of the drive unit.  
      Furthermore, the tray  5  is formed with a recessed portion at its central position so as to mount the cartridge  10  thereon and also formed with an opening for reading out information from the optical disk or writing information thereto.  
      The tray  5  is further provided, on one side portion thereof, with a cam mechanism including cams  7  and  7   a  for guiding the follower pin  18 . These cams  7  and  7   a  are arranged at positions near both end portions of the opening  11  formed to the cartridge body  10   a  so that front ends of the cams  7  and  7   a  face inside the opening  11 . According to such structure, the follower pin  10  can be prevented from contacting the cartridge body  10   a  at the cartridge loading or unloading time.  
      Surfaces of the cams  7  and  7   a  facing each other are formed so as to provide oblique shapes inclining toward the opening ( 11 ) side. According to the formation of such oblique surfaces of the cams  7  and  7   a , the follower pin  18  is moved closely to the cartridge  10  or apart therefrom. In addition, since the follower pin  18  can be smoothly and stably moved, the generation of abnormal noise can be prevented or reduced.  
      A support member  27  is firmly secured to the inner one side wall of the case  2   a  along the moving direction of the tray  5 , and the support member  27  is configured to support the follower pin  18  and the like so as to open or close the shutter  15  of the cartridge  10 . The support member  27  is provided with a rack  16  and the follower pins  18 ,  18  disposed to both ends of the rack  16  through plate springs  17 ,  17 .  
      Each of the follower pins  18 ,  18  is provided with a shaft  18   a  slid able to the cam  7  ( 7   a ) by the relative motion of the follower pin  18  with respect to the cartridge  10 , and a protruded portion  18   b  formed to one end of the shaft  18   a  so as to be engage able with the recessed portion  13   c  of the wheel  13 . On the other hand, each of the plate springs  17 ,  17  is attached so that the follower pin  18  is urged to the cartridge side. The protruded portions  18   b ,  18   b  are designed such that the central position of the shaft  18   a  of the follower pin  18  moving in accordance with the relative motion to the cartridge  10  is always positioned in a direction apart from the opening  11  of the cartridge  10  from the front end position of the cam  7  ( 7   a ). According to such structure, the follower pins  18 ,  18 , which are moved in a direction substantially perpendicular to the relative motion direction to the cartridge  10 , can be smoothly moved.  
      Various equipments or elements for performing recording and reproducing operations to the optical disk mounted in the cartridge  10  are accommodated in case  2   a.    
      With reference to  FIGS. 5 and 6 , the wheel  13  is one example of a drive member of the present invention, and the information reproducing apparatus is one example of an apparatus to which a cartridge is loaded according to the present invention. Furthermore, the follower pin  18  is one example of a follower member of the present invention and the cams  7 ,  7   a  are one example of a cam mechanism of the present invention. The plate spring  17  is also one example of urging means of the present invention.  
      A shutter opening/closing mechanism for opening or closing the shutter  15  of the cartridge  10  will be described hereunder with reference to  FIG. 7 , in which like reference numerals are added to members or elements corresponding to those shown in  FIGS. 5 and 6 .  
      First, as shown in  FIG. 7 ( a ), when the cartridge  10  is mounted on the tray  5  and the tray  5  starts to be loaded inside the information reproducing apparatus  2  by the drive member, not shown, the shaft  18   a  of the one follower pin  18 , which is disposed near the outside of the information reproducing apparatus  2 , slides along the surface of the cam  7   a  so as to face the one end of the opening  11  of the cartridge body  10   a . Then, the protruded portion  18   b  of this one follower pin  18  guided by the cam  7   a  is engaged with one of the recessed portions  13   c  of the wheel  13  exposed from the opening  11  and moved with respect to the cartridge  10  to thereby rotate the wheel  13 .  
      Thereafter, as shown in  FIG. 7 ( b ), the tray  5  is guided deeply inside the information reproducing apparatus  2  so as to be accommodated therein, the shaft  18   a  of the one follower pin  18  is guided by the other one cam  7 , the protruded portion  18   b  of this follower pin  18  is moved apart from the opening  11  of the cartridge body  10   a , and then, the rack  13   b  of the wheel  13  and the rack  16  disposed on the side of the information reproducing apparatus  2  are meshed with each other to thereby further rotate the wheel  13 .  
      Next, as shown in  FIG. 7 ( c ), the shaft  18   a  of the other one follower pin  18  is guided to the opening  11  of the cartridge body  10   a  by the cam  7   a.    
      Furthermore, when the tray  5  is accommodated deeply inside the information reproducing apparatus  2 , as shown in  FIG. 7 ( d ), the protruded portion  18   b  of the other one follower pin  18  is engaged with the exposed other one recessed portion  13   c  of the wheel  13 , which is then rotated to the predetermined position and stopped there. In association with the rotation of the wheel  13 , the shutter  15  is opened through the connection member  14 , and at this time, since the protruded portion  18   b  of the other one follower pin  18  is engaged with the recessed portion  13   c  of the wheel  13 , the wheel  13  can be prevented from rotating in the reverse direction, whereby the shutter  15  can be kept opened fully stably.  
      Further, at the time of unloading the cartridge  10 , when the tray starts to be drawn outward, as shown in  FIG. 7 ( d ), the shaft  18   a  of the other one follower pin  18  is guided by the cam  7   a , and while retiring from the opening  11  of the cartridge body  10   a , the rack  13   b  of the wheel  13  and the rack  16  provided for the information reproducing apparatus  2  are meshed with each other to thereby rotate the wheel  13 .  
      Next, when the tray  5  is further drawn out, as shown in  FIG. 7 ( b ), the shaft  18   a  of the one follower pin  18  is moved in the slid able fashion along the other one cam  7  so as to face a portion near the other end of the opening  11  of the cartridge body  10   a.    
      Thereafter, when the tray  5  is further drawn outward, as shown in  FIG. 7 ( a ), the protruded portion  18   b  of the one follower pin  18  is engaged with the exposed one recessed portion  13   c  of the wheel  13 , whereby the wheel  13  is rotated in the reverse direction and stopped to the predetermined position. In association with this reverse rotation of the wheel  13 , the shutter  15  is closed through the connection member  14 .  
      Furthermore, when the tray  5  is drawn completely outside to the draw-out position, the shaft  18   a  of the one follower pin  18  is guided to the one cam  7   a  and separated from the opening  11  of the cartridge body  10   a.    
      Incidentally, as shown in  FIG. 8 , the shaft  18   a  of the follower pin  18  may be provided, on its outer peripheral surface, with a rotating member  20  (such as roller or like). According to this arrangement, when the shaft  18   a  of the follower pin  18  is moved along the cams  7 ,  7   a  due to the relative movement of the cartridge  10  with respect to the case  2   a , the rotating member  20  slides, while rotating, along the cams  7 ,  7   a , so that the friction resistance is reduced and the smooth movement can be ensured.  
      If the like improvement would be effected to the conventional technology mentioned hereinbefore, as shown in  FIG. 9 , it may be considered that the front end portion of the protruded portion  23  of the shutter opener  22  is constituted by a shaft  24  and a rotating member  25 . However, in such arrangement, as shown in  FIG. 10 , when the recessed portion  13   c  formed to the wheel  13  of the cartridge  10  and the protruded portion  23  of the shutter opener  22  are engaged, there is a fear that the engagement may be made loosen and the wheel can not be rotated by a necessary amount. In addition, at the cartridge loading time, since the pickup member approaches the surface of the optical disk, it is always necessary for the shutter to be opened. For this reason, if the wheel  13  is incompletely rotated, the shutter  15  is not fully opened, and in the worst case, the pickup member may collide with the shutter and break it. Accordingly, it is considered to be impossible to apply the rotating member  25  to the conventional technology or structure.  
      Hereunder, with reference to  FIG. 11 , there is explained a case in which the plate spring  17  which urges the follower pin  18 , shown in  FIG. 6 , toward the cartridge  10  is eliminated.  
       FIG. 11  is a view showing a relationship between the follower pin and the cartridge in the case when an arm is utilized in place of the plate spring shown in  FIG. 6 . In  FIG. 11 , like reference numerals are added to portions or members in  FIG. 6  and the explanations thereof are omitted herein.  
      As shown in  FIG. 11 , a cam groove  41  for guiding the follower pin  18  is formed to one side portion of the tray  5 , and when the follower pin  18  moving along the cam groove  41  relative to the cartridge  10  faces the opening  11  formed to the cartridge body  10   a  and separates from the opening  11 , the cam groove  41  is formed so as to avoid the contacting to the opening  11  or cartridge body  10   a . Further, the cam groove  41  has curved portions  41   a ,  41   a  at portions near both ends of the opening  11  of the cartridge body  10   a . These curved portions  41   a ,  41   a  of the cam groove  41  serve to allow the follower pin  18  to approach or separate from the cartridge  10 . According to this structure, at the time of cartridge loading or unloading time, the follower pin  18  can be prevented from contacting the cartridge body  10   a.    
      Furthermore, an arm  43  is attached, through a rotational shaft  42 , to both end portions of the rack  16  of the support member  27  mounted to one inside wall of the case  2   a , and the follower pin  18  is attached to the front end of this arm  43 .  
      According to the structure mentioned above, by the relative motion to the cartridge  10 , the shaft  18   a  of the follower pin  18  slides along the cam groove  41 , and since the follower pin  18  is limited in its movement by the cam groove  41 , the follower pin  18  can be smoothly moved.  
      As mentioned above, it is not always necessary for the follower pin  18  to be urged on the cartridge side, and for example, the follower pin  18  is substituted for the plate spring  17  shown in  FIG. 6 , and the follower  18  is attached to the rack  16  through the arm  43  rotating around the rotational shaft  42  so that the follower pin  18  is movable along the cam groove  41  formed to the tray  5 .  
      According to the present embodiment, as mentioned above, the shutter apparatus as the shutter mechanism of the present invention includes the follower pin  18  engaging, at a portion of the opening  11  of the cartridge  10 , with a portion of the wheel  13  driven in the cartridge  10  so as to open or close the shutter  15  provided for the cartridge  10 , and also includes the cams  7 ,  7   a  limiting the movement of the follower pin  18  so as to avoid the contact of the follower pin  18  to the opening  11  of the cartridge  10  at the time of disengagement between the follower pin  18  and the portion of the wheel  13 . In other words, the shutter mechanism includes the follower pin  18  engaging, at the opening  11  of the cartridge  10 , with the portion of the wheel driven in the cartridge so as to open or close the shutter provided for the cartridge  10 , and also includes the cams  7 ,  7   a  limiting the movement of the follower pin  18  and positioned between the follower pin  18  and the cartridge  10  at the position at which the follower pin  18  and the portion of the wheel  13  are not engaged with each other.  
      According to such structure, the follower pin  18  does not contact the cartridge  10  and the generation of abnormal noise can be prevented. In addition, since the follower pin  18  is guided by the cams  7 ,  7   a , the follower pin  18  does not contact the cartridge  10 , and the loading or unloading operation of the cartridge can be stably done. Furthermore, since the follower pin  18  does not contact the cartridge  10 , even if the position of the cartridge  10  is largely shifted because of existence of backlash or like, the shutter mechanism is not locked.  
      More specifically, the cams  7 ,  7   a  have the inclining portions, and when the engagement between the follower pin  18  and the portion of the wheel  13  is released, the follower pin  18  is restricted so as to be moved along the inclining portion to be apart from the portion of the wheel  13 . Thus, the follower pin  18  can be surely and smoothly retired from the cartridge  10 .  
      Furthermore, the follower pin  18  has the shaft  18   a  sliding along the cams  7 ,  7   a  through the relative motion and the protruded portion  18   b  formed at both the ends of the shaft  18   a  and engaging with the portion of the wheel  13 . The shaft  18   a  may be provided with a roller so as to roll around the outer periphery of the shaft  18   a . According to this structure, the shaft  18   a  of the follower pin  18  moving through the relative motion of the cartridge  10  with respect to the information reproducing apparatus  2  can contribute to reduce the noise at the time of the sliding motion of the shaft  18   a  on the cams  7 ,  7   a . In addition, the frictional resistance at the sliding time of the shaft  18   a  on the cams  7 ,  7   a  can be reduced by utilizing the roller  20  (rotating member) as the shaft  18   a  of follower pin  18 , so that the noise at the sliding time can be reduced from generating.  
      Further, it is desirable that the center of the shaft  18   a  of the follower pin  18  is positioned in a direction apart from the opening  11  of the cartridge  10  from the position of the front end of the cam  7  ( 7   a ). According to this structure, the follower pin  18  does not directly contact the cartridge  10 , so that the follower pin  18  can be smoothly moved.  
      Furthermore, it is also desirable that the cams  7 ,  7   a  are formed to the portions near both the ends of the opening  11  of the cartridge  10 , and the cams  7 ,  7   a  are formed with the inclining portions for guiding the follower pin  18  in the direction apart from the portion of the wheel  13  when the engagement between the follower pin  18  and the portion of the wheel  13  is released. According to this structure, the follower pin  18  can be surely and smoothly retired from the cartridge  10 .  
      Still furthermore, the shutter mechanism and reproducing means for reproducing information of the optical disk  12  accommodated in the cartridge  10  may be provided. According to this structure, the shutter  15  of the cartridge  10  can be automatically opened or closed to thereby reproduce the optical disk  12 .  
      Furthermore, in the described embodiment, although the shutter mechanism is applied to the information reproducing apparatus  2  configured to load the cartridge  10  to the recording and reproducing position in the case of the information reproducing apparatus  2  and unload it to the drawn-out position for mounting the cartridge  10  on the tray  5 , the shutter mechanism may be applied to so-called a slot-in type information reproducing apparatus.