Abstract:
An information recording medium reproducing system has an insertion opening, a recording medium storing portion and a medium carrying device. Photodetectors are provided for detecting passing of the recording medium and for producing a passing signal when the medium passes. A controller is provided for controlling operation of the medium carrying device. The controller applies a discharge signal to the medium carrying device when the passing signal is not produced within a predetermined time, whereby the medium carrying device is actuated in discharge operation.

Description:
RELATED APPLICATIONS 
   This is a Continuation of application Ser. No. 10/412,575 filed Apr. 14, 2003, now abandoned which in turn is a Continuation Application of Parent application Ser. No. 09/427,588 filed Oct. 27, 1999, now U.S. Pat. No. 6,683,826. The disclosure of the prior applications is hereby incorporated by reference herein in its entirety. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to a system for reproducing information recorded on an information recording medium. 
   The applicant of this patent application has provided an information reproducing system disclosed in Japanese Patent Applications 10-107265 and 10-107266. 
   In the system, an opening is formed at a front panel of a housing for inserting and discharging an optical disc. In the housing, there is provided a plurality of trays for storing recording mediums, a clamp mechanism for positioning the recording medium, and a pickup for reading recorded information. 
   The trays are stacked and disposed adjacent the opening, and vertically moved so as to position a desired tray at the opening and the clamp mechanism. 
   When a user instructs a desired tray, the tray is automatically positioned at the opening. When the user inserts an information recorded medium in the opening, the information recorded medium is automatically stored on the tray. Thereafter the stack of trays is vertically moved to a waiting position. 
   When the user instructs a desired recording medium stored in a tray, the tray is moved to the clamp mechanism, and the information recorded on the recording medium is reproduced by the pickup and a reproducing device. 
   When the user instructs to discharge a recording medium, the tray storing the recording medium is moved to the opening and the recording medium is discharged from the opening. 
   If the user inserts a foreign object in the opening or a recording medium is stuck in the device, and the tray is moved in such a condition, the device may break. 
   SUMMARY OF THE INVENTION 
   An object of the present invention is to provide a system for reproducing information recorded on an information recording medium which may prevent the breakdown of the system caused by abnormal conditions. 
   According to the present invention, there is provided an information recording medium reproducing system having an insertion opening, a recording medium storing portion and a medium carrying device, the system comprising, instructing means for instructing insertion of the medium in the system, detecting means disposed between the insertion opening and the recording medium storing portion for detecting passing of the recording medium and for producing a passing signal when the medium passes, control means for controlling operation of the medium carrying device, the control means being provided for applying a discharge signal to the medium carrying device when the passing signal is not produced within a predetermined time after the insertion instruction, whereby the medium carrying device is actuated in discharge operation. 
   The control means is provided for generating a warning signal for giving a user warning of abnormality when the passing signal is not produced within the predetermined time. 
   The detecting means comprises a plurality of photodetectors. 
   The photodetectors are disposed for discriminating kinds of the recording mediums. 
   These and other objects and features of the present invention will become more apparent from the following detailed description with reference to the accompanying drawings. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
       FIG. 1  is a perspective view showing a fixed chassis; 
       FIG. 2  is a perspective view showing a movable chassis; 
       FIG. 3  is a side view of the pickup; 
       FIG. 4  is a plan view of the pickup and the clamp mechanism; 
       FIG. 5  is a plan view of a tray; 
       FIGS. 6   a  and  6   b  are plan views showing the tray and a CD; 
       FIG. 7   a  is a plan view of a disc carrying mechanism; 
       FIG. 7   b  is a front view thereof; 
       FIG. 8  is a diagram showing an arrangement of photodetectors; 
       FIG. 9  shows a block diagram of a control circuit; and 
       FIG. 10  shows a flowchart of a program in a controller. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to  FIG. 1 , the system of the present invention has a pair of disc carrying mechanisms  1  and  2 , a clamp mechanism  3 , a pickup  4 , a pair of shafts  6   a  and  6   b  mounted on a fixed chassis  5 . 
   Referring to  FIG. 2 , there is provided a vertically movable chassis  7 , a pair of driving plates  8  and  9  for moving the movable chassis  7 , sway members  10 ,  11 ,  12  and  13 . 
   A disc detecting switch HSW is provided at an end portion of the pickup  4 . 
   At lateral both sides with respect to the disc carrying direction X, vertical plates  14 ,  15 ,  16  and  17  having guide grooves  14   a ,  15   a ,  16   a  and  17   a  are extended from the fixed chassis  5 . Engaging pins  14   b  and  17   b  are provided on upper portions of the plates  14  and  17  at the outsides thereof, and engaging pins  15   b  and  16   b  are provided on lower portions of plates  15  and  16 . 
   On both sides of the movable chassis  7 , side plates  18  and  19  are formed to be slid on the plates  14 ,  15 ,  16  and  17 . Cam holes  18   a ,  18   b ,  19   a  and  19   b  are formed in the side plates  18  and  19 . Pins  18   c ,  18   d ,  19   c  and  19   d  are provided on the outside of the plates  18  and  19 . 
   In the driving plate  8 , a pair of stepwise cam holes  8   a  and  8   b  and a pair of guide holes  8   c  and  8   d  are formed. In the driving plate  9 , a pair of stepwise cam holes  9   a  and  9   b  and a pair of guide holes  9   c  and  9   d  are formed. The cam holes  8   a ,  8   b  and cam holes  9   a ,  9   b  are inclined in the opposite directions, and guide holes  8   c ,  8   d  and guide holes  9   c ,  9   d  are reversely disposed in height. 
   In the sway plates  10 ,  11 ,  12  and  13 , notches  10   a ,  11   a ,  12   a  and  13   a  are formed. On the sway plates  12 ,  13 , there is provided support pins  12   c ,  13   c  to be engaged with holes  19   e ,  19   f  of the side plates  19 , and engaging pins  12   b ,  13   b  to be engaged with cam holes  19   a ,  19   b  formed in the side plate  19 . Each of the sway plates  10 ,  11  has the same support pin and engaging pin as the sway plate  12 . 
   The sway plates  10 ,  11 ,  12  and  13  are rotatably mounted on the side plates  18 ,  19  so as to be swayed about the holes  18   e ,  18   f ,  19   e  and  19   f  by the cam holes  18   a ,  18   b ,  19   a  and  19   b.    
   Engaging pins  18   c ,  18   d ,  19   c  and  19   d  engage with guide grooves  14   a ,  15   a ,  16   a  and  17   a  so that the movable chassis  7  is vertically moved. Ends of the pins  18   c ,  18   d ,  19   c ,  19   d  extended from the guide grooves  14   a ,  15   a ,  16   a ,  17   a  are engaged with cam holes  8   a ,  8   b ,  9   a ,  9   b  of the driving plates  8 ,  9 , respectively. The pins  14   b ,  15   b ,  16   b  and  17   b  are slidably engaged with guide holes  8   c ,  8   d ,  9   c ,  9   d  of the driving plates  8 ,  9 . 
   The driving plates  8 ,  9  are horizontally move in the opposite directions by a driving device (not shown), so that the movable chassis  7  is vertically moved by the stepwise cams  8   a ,  8   b ,  9   a ,  9   b.    
   The sway places  10 ,  11 ,  12 ,  13  are swayed by the cam holes  18   a ,  18   b ,  19   a ,  19   b.    
   The pickup  4  is rotatably mounted on the movable chassis  7  by the engagement of a hole  21  with a shaft  20  on the chassis. 
   As shown in  FIG. 1 , a drive pin  24  is engaged with a guide hole  22  of the movable chassis  7  and with an elongated hole  23  of the pickup  4 . By moving the drive pin  24 , the pickup and the clamp mechanism  3  are rotated about the shaft  20 . 
     FIG. 3  is a side view of the pickup  4 , and  FIG. 4  is a plan view of the pickup and the clamp mechanism  3 . 
   As shown in  FIG. 3 , a drive motor  4   a  is provided in a case of the pickup  3 . On the rotating shaft of the motor  4   a , a turntable  4   b  is secured for mounting a CD. A carriage  4   c  is also provided in the case, on which a pickup body (not shown) is mounted. 
   The clamp mechanism  3  is pivotally mounted on the pickup  4  by a hinge  4   d  and has clamp portion  3   a  for clamping the CD on the turntable  4   b.    
   The clamp mechanism  3  is pivoted as shown by numeral  3 ′ in  FIG. 3  for loading the CD on the turntable  4   b . Further, the clamp mechanism  3  and pickup  4  are rotated as shown by dot-dash lines in  FIG. 4  for reproducing the CD. 
     FIG. 5  is a plan view of a tray, and FIGS,  6   a  and  6   b  are plan view showing the tray and the CD. 
   Referring to  FIG. 5 , a tray  25  has a disc supporting plate  25   a  having a V-shaped notch  25   h . On the both sides of the plate  25   a , there is provided a pair of holes  25   b ,  25   c  in which shafts  6   a ,  6   b  ( FIG. 1 ) are to be engaged, engaging pins  25   d ,  25   e ,  25   f  and  25   g  to which sway plates  10 ,  11 , 12 ,  13  ( FIG. 2 ) are engaged, and recesses  25   i ,  25   j  for preventing the carrying mechanisms  1 ,  2  from contacting with the tray  25 . 
   In the V-shaped notch  25   h , the pickup  4  and clamping mechanism  3  are to be positioned as shown by the dot-dash lines in  FIG. 4  at the reproduction of the CD. 
   In the present embodiment, six trays  25  are stacked and supported by the shaft  6   a ,  6   b  ( FIGS. 1 and 2 ). 
   An elevating mechanism (not shown) is provided to be engaged with side plates  25   de  and  25   fg  of a lowermost tray so as to elevate the stack of the trays along the shafts  6   a ,  6   b.    
   Referring to  FIGS. 6   a  and  6   b , in the recess  25   i ,  25   j  ( FIG. 5 ), the disc carrying mechanisms  1 ,  2  are disposed. The disc carrying mechanisms are positioned toward the tray in the operating state as shown in  FIG. 6   a , and retracted in the non-operating state as shown in  FIG. 6   b  when the trays are vertically moved. 
     FIG. 7   a  is a plan view of the disc carrying mechanism, and  FIG. 7   b  is a front view thereof. 
   The disc carrying mechanism  1  comprises a rotating shaft  1   b  having a roller  1   a  made of rubber, a support frame  1   c  for supporting the shaft  1   b , a driving shaft  1   d  rotatably mounted on the fixed chassis  5  and an engaging plate  1   f.    
   The shaft  1   d  is connected to the shaft  1   b  by a worm  1   h  and worm wheel  1   i , and connected to a rotating shaft of a motor  26  by a pulley  1   g  and a belt  27 . The shaft id is further connected to a pulley  2   g  ( FIG. 2 ) of the carrying mechanism  2  by a belt  28 . 
   The frame  1   c  is rotatably mounted on the shaft  1   d  and vertically swingably mounted at an end  1   j . The engaging plate if is urged by a spring  1   k  to the roller  1   a  so as to grip the CD together with the roller  1   a  to carry the disc. 
   Thus, the rollers  1   a ,  2   a  are rotated, and the engaging plates  1   c  and  2   c  are swung by the motor  26 , thereby carrying the CD inserted in the front opening to the turntable and discharging the disc. 
   Referring to  FIG. 8 , there is provided three photodetectors P 1 , P 2 , P 3  for detecting the size of the CD. The detectors P 1  and P 2  are disposed at a distance smaller than the diameter of the 8 cm disc CD 1 , and detectors P 1  and P 3  are disposed at a distance larger than the diameter of 8 cm disc CD 1  and smaller than the diameter of the 12 cm disc CD 2 . Thus, the discs CD 1  and CD 2  can be discriminated. 
     FIG. 9  shows a control circuit  29 . As shown in  FIG. 9 , each of the photodetectors P 1  to P 3  is composed by a light emitting diode and a photo-transistor connected between Vcc and the ground GND. 
   When the CD passes between the photodetectors P 1 –P 3 , voltages at resistors R 1 , R 2  and R 3  change to provide signals S 1 , S 2  and S 3  which are applied to a controller  30  so that the existence and the size of the CD are detected. 
   There is provided instruction switches  32   a – 32   f  for instructing the addresses of six trays  25 , a cancel switch  32   g  for canceling the address instruction, a driving circuit  33  for driving the motor  26  and a timer  31 . 
   The operation of the system is described with reference to  FIG. 10  showing a flowchart of a program in the controller  30 . 
   At a step  100 , it is determined whether the address number of the tray  25  is instructed by operating one of the switches  32   a – 32   f , and the instructed tray is positioned to the inserting opening by the elevator mechanism (step  101 ). At a step  102 , the door of the opening is opened and the program timer  31  is started (step  103 ). 
   At a step  104 , it is determined whether the signal S 1  of the first photo-detector P 1  becomes logic H which means a normal medium is inserted in the opening. If H, the program proceeds to a step  105 , if L, the program goes to a step  109 . At the step  105 , the motor  26  is operated to rotate the roller  1   a ,  2   a  in the feeding direction. 
   At a step  106 , it is determined whether there is an abnormal condition based on the signals S 1 –S 3 . If there is no abnormality, the disc is inserted (step  107 ). The completion of the disc insertion is detected by the switch HSW, and the motor  26  is stopped. The tray stack is vertically moved to position the desired disc at a waiting position or to reproduce the disc (step  108 ). 
   At the step  109 , it is determined whether a first set time, for example, 4 seconds, elapses. If the time elapses at the step  109 , or if there is abnormality at the step  106 , the rollers  1   a ,  2   a  are rotated in the reverse direction at a step  120 . If the set time does not elapse at the step  109 , it is determined whether the instructed address set at the step  100  is canceled by the cancel switch  32   g  of  FIG. 9  (step  133 ). If canceled, the rollers  1   a ,  2   a  are reversely rotated (step  120 ). 
   At a step  121 , it is determined whether all output signals S 1 –S 3  of the photodetectors P 1 –P 3  are logic L because of the reverse rotation of rollers  1   a ,  2   a . If it is the case, it is determined that a foreign object does not exist. Thereafter, a second time (500 msec) is set in the timer  31  at a step  122 , and it is determined whether the second time elapses at a step  123 . If not, a foreign object is reconfirmed at the step  121 . If yes, the rollers  1   a ,  2   a  are stopped (step  124 ) and the door closed (step  125 ). When the door is normally closed at a step  126 , the CD is positioned at the waiting position or reproduced (step  128 ). If the door is normally closed, the door is opened (step  127 ), and the program is returned to the step  120 . 
   When all signals S 1 , S 2  and S 3  are not logic L at the step  121 , the reverse rotation is continued (step  129 ) and then the rotation is stopped (step  130 ). 
   At a step  131 , the exist of a foreign object is reconfirmed. When a foreign object is confirmed, warning is displayed and/or alarm is emitted at a step  132 , and the operation of the device is stopped. 
   In accordance with the present invention, when insertion of a disc is not detected after the elapse of a predetermined time, disc carrying rollers are rotated in the reverse direction. In addition, after the elapse of the time, since the carrying rollers are reversely rotated, a disc and a foreign object cannot be inserted in the device. 
   While the invention has been described in conjunction with preferred specific embodiment thereof, it will be understood that this description is intended to illustrate and not limit the scope of the invention, which is defined by the following claims.