Abstract:
To provide a “disk device” that does not waste a power during waiting for disk insertion and thus can save power consumption. The disk device includes: a casing equipped with an insertion port to which a disk is inserted; a conveying mechanism for conveying a disk, which is provided inside the insertion port; a switching type detecting switch that is switched to a detection state in accordance with a movement force of a disk inserted from the insertion port in an insertion direction; and an optical detecting member that is switched to a detection state when a disk inserted from the insertion port blocks an optical path, wherein when the detecting switch is switched to a detection state, power supply to the optical detecting member is started.

Description:
RELATED APPLICATIONS 
     The present application claims priority to Japanese Patent Application Number 2008-159443, filed Jun. 18, 2008, the entirety of which is hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a disk device that can determine whether a normal disk is installed to a normal position by use of an optical detecting member and in addition, can save power consumption during waiting for disk insertion. 
     2. Description of the Related Art 
     A slot-in type disk device to be inserted from a slit-like insertion port formed in a casing is equipped with a detecting unit disposed inside the insertion port. If the detecting unit detects disk insertion, a conveying mechanism including a transport roller starts operating and transports the disk into the device. Here, it is necessary to determine whether the disk inserted from the insertion port and transported is a normal disk. For example, provided that a normal disk has a diameter of 12 cm, when a disk having a diameter of 8 cm, a disk that is not circular in outer shape, or a rectangular card is inserted, it is necessary to determine the disk or card as a foreign material, not a normal disk, and to immediately discharge the disk or card from the insertion port. 
     A disk device disclosed in Japanese Unexamined Patent Application Publication No. 2006-99833 is equipped with a pair of detecting members disposed inside an insertion port and sliding along an outer edge of an inserted disk. The pair of detecting members is biased to get close to each other by means of spring force. If it is detected that the detecting members has been pressed by the outer edge of a disk and moved by a predetermined distance, it is determined that any disk has been inserted from the insertion port. Then, a conveying mechanism starts operating. After that, during a period where the conveying mechanism transports the disk, the pair of detecting members slides along the outer edge of the disk, and a distance between the members is changed. By detecting the change in distance, whether a normal disk has been transported in a normal way is determined. 
     A disk device disclosed in Japanese Unexamined Patent Application Publication No. 2005-251329 employs plural optical detecting members as a detecting unit. In the disk device, if a disk blocks an optical path of each detecting member, it is determined that any disk has been inserted. Then, a conveying mechanism starts operating to convey the disk into the device. By monitoring a combination of detection outputs from the optical detecting members during conveyance of the disk into the device, it is determined whether a normal disk has been transported in a normal way. 
     The disk device disclosed in Japanese Unexamined Patent Application Publication No. 2006-99833 has the following problem: because the detecting members keep sliding along the outer edge of the disk during disk transport, a high resistance is applied when the disk is transported into the device and in addition, if the outer edge of the inserted disk is not round or a card or the like is inserted by mistake, such a disk or card is caught on the detecting members and then could not be taken out from the insertion port. 
     Further, the disk device designed to detect a disk with an optical detecting member as disclosed in Japanese Unexamined Patent Application Publication No. 2005-251329 involves the following defect: because the device needs to continuously supply a power to the optical detecting member during waiting for disk insertion so as to detect disk insertion when a disk is inserted, a large amount of power is consumed during waiting for disk insertion. For example, if the device is an in-vehicle disk device, a battery power is excessively consumed while a vehicle engine is stopped. 
     SUMMARY OF THE INVENTION 
     The present invention has been accomplished with a view to solving the problems involved in the related art and accordingly, it is an object of the present embodiments to provide a disk device that can reduce the number of detecting mechanisms that slide on a disk by operating a conveying mechanism or the like based on a detection operation of an optical detecting member and in addition, can save power consumption while waiting for disk insertion. 
     A disk device according to the present invention includes: a casing equipped with an insertion port to which a disk is inserted; a conveying mechanism for conveying a disk, which is provided inside the insertion port; a switching type detecting switch that is switched to a detection state in accordance with a movement force of a disk inserted from the insertion port in an insertion direction; and an optical detecting member that is switched to a detection state when a disk inserted from the insertion port blocks an optical path, wherein when the detecting switch is switched to a detection state, power supply to the optical detecting member is started. 
     The disk device of the present embodiments is equipped with an optical detecting member as a detecting unit for detecting a disk in the device. The detection of a disk with the optical detecting member triggers various kinds of operation control, making it possible to reduce the number of detecting mechanisms designed to detect a disk by direct contact therewith. Thus, if a foreign material not having a round outer shape, there rarely arises a problem that the material is caught on the detecting mechanisms. In addition, no power is supplied to the optical detecting member during waiting for disk insertion, and only when a detecting switch is switched to a detection state in response to an inserted disk, a power is supplied to the optical detecting member, with the result that a power consumed during waiting for disk insertion can be saved. 
     According to the present embodiments, when the optical detecting member is switched to a detection state, the conveying mechanism starts operating to allow disk conveyance. Further, the detecting switch and the optical detecting member are both provided between the insertion port and the conveying mechanism. 
     The detecting unit for activating the conveying mechanism is configured using the optical detecting member, thereby making it possible to avoid such a situation that the detecting unit used for activating the conveying mechanism obstructs disk conveyance after the conveying mechanism starts disk conveyance and in addition, avoid such a problem that a foreign material inserted from an insertion port is caught on the detecting unit used for activating the conveying mechanism. 
     According to the present embodiments, it is preferred that, when the detecting switch and the optical detecting member are both switched to a detection state, the conveying mechanism starts operating. 
     With this structure, although the detecting switch can be operated, the conveying mechanism is not operated when a foreign material having a shape that cannot block an optical path of the optical detecting member is inserted from an insertion port. Thus, it is possible to prevent the foreign material from being transported into the device. 
     Further, the disk device of the present embodiments can be configured as follows: it is determined whether an object being transported with the conveying mechanism is a disk of a normal size by monitoring detection output of the optical detecting member. 
     By detecting a shape of an inserted object with the optical detecting member, it is possible to avoid such a situation that the detecting mechanism for detecting the shape slides over a disk and increases a conveyance load of the disk or such a problem that a foreign material is caught on the detecting mechanism. 
     For example, according to the present embodiments, the optical detecting member is provided in such a position where a disk inserted from the insertion port blocks an optical path if the disk is a disk of a normal size and the member is kept in a detection state during a period from when the power supply to the member is started until when the disk reaches a normal installation position. 
     Further, according to the present embodiments, the optical detecting member is provided in a position on one side of a center line which a disk transported into the device passes, away from the center line and opposite to the inside of an outer edge of the disk on the insertion port side. 
     If the optical detecting member is disposed as above, in the case where a normal disk is transported, a transport operation can be continued until the disk reaches a normal installation position, while in the case where a foreign material is transported, the material is immediately determined as not normal one, and processing can be shifted to a discharge operation. 
     Further, the disk device of the present embodiments can be configured as follows: the optical detecting member is provided in two positions on one side of the center line which a disk transported into the device passes, away from the center line, and the two optical detecting members are disposed at the same distance from a center of the disk having reached the normal installation position, and the two optical detecting members are both kept in the detection state until when the power supply to the member is started until when the disk of a normal size reaches the normal installation position. 
     Detection outputs of the two optical detecting members are both monitored to thereby determine whether a normal disk is transported up to a normal installation position, making it possible to enhance an accuracy of determination as to whether a transported object is a normal disk. 
     Further, according to the present embodiments, if it is not detected that a disk reaches a installation end position in the casing within a predetermined period from when the optical detecting member is switched to a detection state, it is determined that the disk has not reached a normal installation position, and processing is shifted to an operation of discharging the disk. 
     Further, according to the present embodiments, it is preferred that the disk device further includes: a movable member that is moved toward a disk thickness direction by a disk inserted from the insertion port, wherein the movable member causes the detecting switch to operate and switch to a detection state. 
     With the above structure where the movable member designed to move in a disk thickness direction causes the detecting switch to operate, the mechanism for operating the detecting switch does not slide over the outer edge of a disk. Thus, if a disk having any outer shape other than a round shape or a card is inserted, the disk or card is rarely lodged inside the disk and can be smoothly discharged. 
     However, the detecting switch of the present embodiments may be operated by a mechanism designed to move while sliding over the outer edge of an inserted disk. In addition, an actuator of the detecting switch may be driven directly by a disk. 
     Further, the optical detecting member of the present embodiments may be used as a detecting unit for detecting that a normal disk is transported to an installation position or a detecting unit for detecting that a normal disk or other objects are discharged from a casing as well as the detecting unit for activating the conveying mechanism or the detecting unit for detecting whether an object being transported is a normal disk. 
     According to the disk device of the present embodiments, the detecting units other than the detecting switch for detecting that a disk is inserted from an insertion port may be configured using the optical detecting member. Hence, the detecting unit for activating the conveying mechanism and the detecting unit for determining a shape of a transported object may be disposed not to contact the disk being conveyed, an increase in disk conveyance load may be avoided, and the possibility that a foreign material is caught on the detecting unit in the device may be decreased. 
     Further, it may be unnecessary to supply a power to the optical detecting member during waiting for disk insertion. Accordingly, power consumption may be saved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing the overall structure of a disk device according to an exemplary embodiment; 
         FIG. 2  is a right side view of the device in  FIG. 1 ; 
         FIG. 3  is a plan view of the disk device just after a disk is inserted from an insertion port; 
         FIG. 4  is a plan view of the disk device, which shows how a disk is transported with a transport roller; 
         FIG. 5  is a plan view of the disk device, which shows how a disk transported with a transport roller reaches a transport end position; 
         FIG. 6  is a plan view of the disk device, which shows how a disk is clamped to a turntable; and 
         FIG. 7  is a flowchart of an operation from disk insertion to completion of disk transport. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  is a perspective view showing the overall structure of a disk device according to an exemplary embodiment.  FIG. 2  is a right side view of the device in  FIG. 1 . In  FIG. 2 , a right-sided slider  30   a  is not illustrated.  FIGS. 3 to 6  are plan views showing a change in operation state of the disk device. In  FIGS. 1 to 6 , an X 1  direction represents rightward, an X 2  direction represents leftward, a Y 1  direction represents forward, a Y 2  direction represents backward, a Z 1  direction represents upward, and a Z 2  direction represents downward. 
     The disk device of this embodiment allows installation of a disk D having a perfect circular shape with a diameter of 12 cm such as a DVD (digital versatile disk) or a CD (compact disk) as a normal disk. If any object other than a normal disk, for example, an irregular disk such as an 8 cm-diameter disk or an elliptical disk or a rectangular card C, is inserted, the disk device discharges the disk or card as a foreign material. 
     As shown in  FIGS. 3 to 6 , the disk device includes a casing  1  made of a metal plate. As for an in-vehicle disk device, the casing  1  has a size equal to, for example, 1 DIN size or ½ DIN size, and is embedded into an in-car installment panel. 
     As shown in  FIGS. 3 to 6 , the casing  1  includes a front panel  2  directed toward the Y 1  direction, a rear plate  2  directed toward the Y 2  direction, and side plates  4  and  5  directed toward the X 1  and X 2  directions. Further, the casing  1  includes a top plate and a bottom plate. In the front panel  2 , a thin insertion port (not shown) is formed in a lateral direction (X 1 -X 2  direction). A decorative panel made of a synthetic resin is attached to the front of the front panel  2  of the casing  1 , and various operation members and a display device are provided on the front of the decorative panel. The decorative panel has a panel portion insertion port communicating with the insertion port. The disk D is inserted into the casing  1  through the panel portion insertion port and the insertion port formed in the front panel  2 . 
     A mechanism unit  10  as shown in  FIG. 1  is accommodated in the casing  1 . The mechanism unit  10  includes a drive base  11  and a cramp base  12  at the bottom and the top thereof, respectively. The drive base  11  and the cramp base  12  are both formed by bending a metal plate. The drive base  11  is provided with a connecting shaft  13  extending in the X 1  and X 2  directions on the Y 2  side. One end of the cramp base  12  on the Y 2  side is rotatably supported to the connecting shaft  13 . 
     As shown in  FIGS. 1 ,  2 , and  3  to  6 , plural dampers ( 15   a ,  15   b , and  15   c ) that elastically support the drive base  11  are provided inside the casing  1 . The dampers  15   a ,  15   b , and  15   c  are obtained by filling oil into an elastic bag. The dampers  15   a ,  15   b , and  15   c  are fixed to the inner surface of the casing  1 . Support shafts fixed to the drive base  11  are supported by the dampers  15   a ,  15   b , and  15   c . After the disk D has been installed to the mechanism unit  10 , the disk D is rotated with the drive base  11  being elastically supported by the dampers  15   a ,  15   b , and  15   c.    
     As shown in  FIG. 2 , a rotating unit  20  is provided on the Y 1  side of the drive base  11 . The rotating unit  20  includes a spindle motor fixed onto the drive base  11 , and a synthetic resin-made turntable  23  fixed to a rotating shaft of the spindle motor. 
     As shown in  FIG. 1 , an optical head  25  is mounted to the drive base  11 . The optical head  25  is movably supported by a guide mechanism provided on the drive base  11  and in addition, equipped with a thread mechanism for reciprocating the optical head  25  along the guide mechanism. The optical head  25  is moved in a radius direction of the disk D by the thread mechanism along a recording surface of the disk D clamped to the turntable  23 . 
     As shown in  FIG. 1 , at the end of the clamp base  12  on the Y 1  side, a damper  27  made of a synthetic resin is rotatably supported and in addition, a leaf spring  26  that presses the rotating shaft of the damper  27  downward (Z 2  direction) is provided. 
     As shown in  FIGS. 1 and 2 , a projection  12   a  protruding in the X 1  direction is integrally formed at the end of the drive base  11  on the Y 2  side. A torsion coil spring  17  is attached to the projection  12   a . One arm of the torsion coil spring  17  is hung on the drive base  11  and the other arm is hung on the clamp base  12 . The clamp base  12  is kept biased toward a counterclockwise direction on the connecting shaft  13 . In other words, the clamp base  12  is kept biased to be turned and pressed against the turntable  23 . 
     As shown in  FIG. 2 , a lifting shaft  18  protruding in the X 1  direction is fixed to the end of the clamp base  12  on the Y 1  side. In the case of applying an upward force (Z 1  directional force) to the lifting shaft  18 , the cramp base  12  is turned clockwise against the biasing force of the torsion coil spring  17  and then, the damper  27  is lifted from the turntable  23 . 
     As shown in  FIG. 1  or  3 , a pair of stopper members  16   a  and  16   b  protruding downwardly is provided on both sides of the cramp base  12 . The stopper members are metal pins. The pins are adjusted such that the center of the disk D transported into the casing  1  is aligned with the center of the turntable  23  when the outer edge of the disk D abuts against the stopper members  16   a  and  16   b.    
     As shown in  FIGS. 1 and 3 , the driver base  11  is provided with the right-sided slider  30   a  on the X 1  side and with a left-sided slider  30   b  on the X 2  side. As shown in  FIG. 1 , a guide elongate hole  31  extending in a front-back direction (Y 1 -Y 2  direction) is formed in the right-sided slider  30   a , and a guide shaft  19  is fixed to the drive base  11 . The guide elongate hole  31  and the guide shaft  19  are paired, and one right-sided slider  30   a  includes the plural pairs. However, only one pair is illustrated in  FIG. 1 . The right-sided slider  30   a  can reciprocate in the Y 1 -Y 2  direction by the guide elongate hole  31  sliding over the guide shaft  19 . Likewise, the left-sided slider  30   b  is supported in the form of being movable to and fro on the X 2  side of the drive base  11 . 
     A motor M is provided behind the drive base  11  on the left side. A power of the motor M moves the left-sided slider  30   b  to and fro. As shown in  FIG. 4 , a link slider  46  is disposed on the Y 1  side at the bottom of the mechanism unit  10  in the form of being movable in the X 1 -X 2  direction. As shown in  FIGS. 4 and 6 , a reversing lever  47  is provided between the link slider  46  and the right-sided slider  30   a . The reversing lever  47  is supported rotatably on a support shaft  47   a . A connecting shaft  47   b  inserted to one arm of the reversion lever  47  is connected to the link slider  46 , and a transmitting shaft  47   c  inserted to the other arm is connected to the right-sided slider  30   a.    
     If the left-sided slider  30   b  is moved in the Y 1 -Y 2  direction by a power of the motor M, a movement force thereof is transmitted to the right-sided slider  30   a  through a link mechanism including the link slider  46  and the reversing lever  47 , and the right-sided slider  30   a  and the left-sided slider  30   b  are moved in the Y 1 -Y 2  direction in sync with each other. In a standby state as shown in  FIGS. 1 and 2 , the right-sided slider  30   a  and the left-sided slider  30   b  are both moved backward (Y 2  direction). 
     As shown in  FIGS. 3 to 6 , a trigger member  14  is provided on the Y 2  side of the mechanism unit  10 . The trigger member  14  includes an arm  14 B rotatably supported onto the drive base  11  and a detecting pin  14 A fixed to the arm  14 B in an opposite position to the outer edge of the transported disk D. 
     If the normal disk D having the diameter of 12 cm is transported and moved up to a position shown in  FIG. 5 , the detecting pin  14 A is pressed by the outer edge of the disk D and the arm  14 B is turned counterclockwise. At this time, a gear is engaged by a rotating force of the arm  14 B to thereby form a transmitting path of a power transmission mechanism. By forming the transmitting path of the power transmission mechanism, a power of the motor M is transmitted to the left-sided slider  30   b  as a linear movement force in the Y 1  direction, and the right-sided slider  30   a  and the left-sided slider  30   b  are moved in the Y 1  direction in sync with each other. 
     The following description is focused on the right-sided slider  30   a . The right-sided slider  30   a  and the left-sided slider  30   b  have the same functions, and a shape and structure of the left-sided slider  30   b  are similar to those of the right-sided slider  30   a.    
     As shown in  FIG. 1 , the right-sided slider  30   a  is equipped with a clamp control cam  32 . The clamp control cam  32  has a cam elongate hole  32   a  extending upwardly (Z 1  direction) toward the front side (Y 1  direction), and a clearance hole portion  32   b  having a large diameter and communicating with the cam elongate hole  32   a  on the Y 2  side. The lifting shaft  18  attached to the cramp base  12  is inserted so as to move inside the cam elongate hole  32   a  and the clearance hole portion  32   b.    
     In the standby state shown in  FIG. 1 , since the right-sided slider  30   a  is moved backward (Y 2  direction), the lifting shaft  18  is hitched up in the Z 1  direction in the cam elongate hole  32   a . At this time, the cramp base  12  is turned clockwise to set an unclamped state in which the damper  27  is lifted from the turntable  23 . When a center hole of the normal disk D is moved onto the turntable  23  and the motor M is driven to move the right-sided slider  30   a  forward (Y 1  direction), the lifting shaft  18  is moved to the clearance hole portion  32   b . At this time, the cramp base  12  is turned counterclockwise by means of an elastic force of the torsion coil spring  17 , and the damper  27  presses the center portion of the disk D against the turntable  23  to clamp the disk D to the turntable  23 . 
     As shown in  FIG. 1 , a locking cam portion  33  is provided to the right-sided slider  30   a . The locking cam portion  33  includes a lock elongate hole  33   a  extending in a back-to-forth direction and a clearance hole portion  33   b  having the large diameter and communicating with the Y 2  side of the lock elongate hole  33   a.    
     In the standby state shown in  FIG. 1 , if the right-sided slider  30   a  is moved in the Y 2  direction, a captive shaft (not shown) fixed to the inner surfaces of the right and left side plates  4  and  5  of the casing  1  is held in the lock elongate hole  33   a . At this time, the mechanism unit  10  is held not to move inside the casing  1 , and the disk D transported from the insertion port can easily move into a space between the turntable  23  and the damper  27  lifted from the turntable  23 . If the right-sided slider  30   a  is moved toward the Y 1  direction, the damper  27  moves down to clamp the center portion of the disk D and in addition, the captive shaft is unlocked from the lock elongate hole  33   a  and then moved to the clearance hole portion  33   b . At this time, the mechanism unit  10  is not locked in the casing  1  but elastically supported by the dampers  15   a ,  15   b , and  15   c . Thus, external vibrations can be easily absorbed by the dampers  15   a ,  15   b , and  15   c  while the disk D is rotated on the turntable  23 , making it possible to prevent the vibrations from directly influencing the mechanism unit  10 . 
     As shown in  FIGS. 1 and 2 , a conveying mechanism  40  is provided between the insertion port and the rotating unit. 
     The conveying mechanism  40  includes a transport roller  41  and a stationary guide unit  43  facing the Z 1  side of the transport roller  41 . 
     The stationary guide unit  43  is made of a synthetic resin material having a low friction coefficient and fixed to a lower surface of the top plate of the casing  1  in an unmovable form. As shown in  FIG. 2 , the stationary guide unit  43  has a lower surface  43   a  as a guide surface extending laterally in the Y 1 -Y 2  direction. 
     In this embodiment, the conveying mechanism  40  is composed of one transport roller  41  and the stationary guide unit  43 . However, the conveying mechanism  40  is not limited to this structure. For example, a driven roller opposite to the transport roller  41  may be adopted in place of the stationary guide unit  43 . 
     The transport roller  41  is formed into a cylindrical shape with a material having a high friction coefficient such as synthetic rubber, and attached around a metal-made roller shaft  42 . Right and left ends of the roller shaft  42  are supported to a roller bracket  44 . 
     The roller bracket  44  is made of a metal plate. As shown in  FIGS. 1 and 2 , the roller bracket  44  includes a right-sided support portion  44   a  formed on the X 1  side, a right-sided leading portion  44   b  extending upward from the tip end of the right-sided support portion  44   a  on the Y 1  side, and a left-sided support portion  44   c  formed on the X 2  side, and a left-sided leading portion  44   d  extending upward from the tip end of the left-sided support portion  44   c  on the Y 1  side. 
     A support hole  44   e  is formed in the right-sided leading portion  44   b , and a support hole  44   f  is formed in the left-sided leading portion  44   d . The support holes  44   e  and  44   f  are positioned along the axial line parallel to the X 1 -X 2  axis. A pair of short support shafts  45 ,  45  is fixed to the inner surfaces of the right and left side plates  4  and  5  of the casing  1 . The support holes  44   e  and  44   f  are supported by the support shafts  45 ,  45  and the roller bracket  44  is supported rotatably on the support shafts  45 ,  45 . A tension coil spring (not shown) is stretched between the roller bracket  44  and the bottom plate of the casing, and the roller bracket  44  is kept biased in a counterclockwise direction in  FIG. 2 . 
     As shown in  FIG. 2 , one retention hole  44   g  is formed at the end of the right-sided support portion  44   a  of the roller bracket  44  on the Y 2  side. Likewise, another retention hole  44   g  is formed at the end of the left-sided support portion  44   c  on the Y 2  side. Right and left ends of the roller shaft  42  are inserted to the retention holes  44   g ,  44   g . In the standby state shown in  FIG. 1 , the roller bracket  44  is biased counterclockwise by means of an elastic force of the tension coil spring, and the elastic force presses the roller shaft  42  against the stationary guide unit  43 . 
     As shown in  FIGS. 3 to 6 , a pinion gear  48  is fixed to the end of the roller shaft  42  on the X 2  side, and a driving gear  49  is provided inside the side plate  5  on the left side (X 2  side) of the casing  1  and applied with a torque of a transport motor (not shown). During a period from when the device waits for insertion of the disk D as shown in  FIGS. 1 and 2  until when the disk D is transported up to a predetermined installation end position as shown in  FIG. 5 , the roller bracket  44  is turned counterclockwise and thus, the pinion gear  48  is engaged with the driving gear  49 . During this period, a torque of the transport roller is transmitted to the pinion gear  48  from the driving gear  49 , and the roller shaft  42  is successively rotated in a direction in which the disk D is transported. 
     As shown in  FIG. 2 , the roller bracket  44  includes an opposing guide portion  44   h  connecting an upper edge of the right-sided support portion  44   a  and an upper edge of the left-sided support portion  44   c . More specifically, the right-sided support portion  44   a  is bent downwardly at right angle on the X 1  side of the opposing guide portion  44   h , and the left-sided support portion  44   c  is bent downwardly at right angle on the X 2  side of the opposing guide portion  44   h.    
     A guide surface  44   i  as an upper surface of the opposing guide portion  44   h  is flat. In the standby state shown in  FIG. 2 , the guide surface  44   i  is inclined upwardly (Z 1  direction) toward the back side (Y 2  direction). 
     A movable guide unit  50  as a movable member is provided between the conveying mechanism  40  and the front plate  2  having an insertion port. The movable guide unit  50  is made of a synthetic resin material having the same friction coefficient as the stationary guide unit  43 , and its lower surface forms a smooth guide surface  51 . The guide surface  51  is positioned opposite to and above the guide surface  44   i  of the opposing guide portion  44   h  of the roller bracket  44 . 
     Short support shafts  52 ,  52  protruding in the X 1  and X 2  directions are integrally attached to the tip end (Y 1  side) of the movable guide unit  50 . The support shafts  52 ,  52  are rotatably supported to bearings provided to both side plates of the casing. The movable guide unit  50  is biased and turned clockwise on the support shafts  52 ,  52  by means of a biasing force of a spring member (not shown) under its own weight. A stopper unit  53  is formed on the upper surface of the movable guide unit  50  in a position closer to the Y 1  side than the support shafts  52 ,  52 . The movable guide unit  50  is designed to stop rotating clockwise if the stopper portion  53  abuts against a lower surface of the top plate. Under such a condition that the movable guide unit  50  is inclined as shown in  FIG. 2 , the disk D inserted from the insertion port can easily abut against the guide surface  51 . 
     In the standby state as shown in  FIG. 2 , a distance between the guide surface  51  as a lower surface of the movable guide unit  50  and the guide surface  44   i  of the opposing guide portion  44   h , which are opposite to each other, is wide on the insertion port side and gradually reduces toward the transport roller  41 . 
     As shown in  FIG. 1 , a detecting switch S 1  incorporating a mechanical switching contact is fixed to almost the center of the front end of the stationary guide unit  43  in the X 1 -X 2  direction (end portion on the Y 1  side). An actuator Sa of the detecting switch S 1  protrudes in the Y 1  direction. Further, a recess  54  is formed at the top of the end portion of the movable guide unit  50  on the Y 2  side. When the movable guide unit  50  is turned counterclockwise against a biasing force of the spring member, the actuator Sa is pressed against the bottom surface of the recess  54  to switch an output of the detecting switch S 1  from OFF to ON. 
     Lifting projections  55 ,  55  protrude in the X 1  and X 2  directions at the rear end of the movable guide unit  50 . 
     As shown in  FIG. 1 , a roller control cam unit  34  is provided on the Y 1  side of the right-sided slider  30   a . The roller control cam unit  34  includes an upper guide portion  34   a  formed on an upper side, a lower restraint portion  34   b  formed in a position closer to the Y 2  side than the upper guide portion and lower than the upper guide portion, and an inclined guide hole  34   c  communicating with the upper guide portion  34   a  and the lower restraint portion  34   b . One end of the roller shaft  42  on the X 1  side is slidably inserted to the roller control cam  34 . 
     A guide control cam unit  35  is provided at the end of the right-sided slider  30   a  on the Y 1  side. The guide control cam unit  35  includes a lifting guide portion  35   a  on the Y 1  side, and a retention guide portion  35   b  extending to the Y 2  side. The lifting guide portion  35   a  is inclined upwardly toward the rear side (Y 2  direction). The retention guide portion  35   b  forms a flat surface extending along the Y 1 -Y 2  direction. The attitude of the lifting projection  55  formed on the movable guide unit  50  is controlled by the guide control cam unit  35 . 
     In the standby state shown in  FIG. 1 , the right-sided slider  30   a  is moved in the Y 2  direction and thus, the right end of the roller shaft  42  is positioned inside the upper guide portion  34   a  of the roller control cam unit  34 . An opening width in the vertical direction of the upper guide portion  34   a  is larger than the diameter of the roller shaft  42 . As shown in  FIG. 2 , the roller shaft  42  is pressed to the stationary guide unit  43  by means of biasing force of the roller bracket  44  turned counterclockwise by the tension coil spring. 
     Further, in the standby state shown in  FIG. 1 , the lifting guide portion  35   a  formed at the end of the right-sided slider  30   a  on the Y 1  side is moved toward the Y 2  direction away from the lifting projection  55 , and the movable guide unit  50  is turned clockwise. 
     If the normal disk D having the perfect circle shape with the diameter of 12 cm is transported and reaches a normal clamp-enabled position where the disk can be clamped, the motor M is driven, and the right-sided slider  30   a  and the left-sided slider  30   b  are moved toward the Y 1  direction in sync with each other. As described above, if the right-sided slider  30   a  is moved to the Y 1  direction, a clamping operation is performed to disengage the mechanism unit  10 . 
     Further, if the right-sided slider  30   a  and the left-sided slider  30   b  are moved toward the Y 1  direction, the right end of the roller shaft  42  is guided downwardly along the inclined guide hole  34   c  of the roller control cam unit  34  and retained in the lower restraint portion  34   b . As a result, the roller bracket  44  is turned clockwise, and the transport roller  41  is moved away from the stationary guide unit  43  and the disk D and in addition, the opposing guide portion  44   h  is also moved downwardly from the movable guide unit  50 . Moreover, the lifting projection  55  formed on the movable guide unit  50  is lifted by the lifting guide portion  35   a  and slides over the retention guide portion  35   b . At this time, the movable guide unit  50  takes substantially horizontal attitude. 
     As shown in  FIG. 3 , a circuit board  70  is attached to a lower surface of the top plate of the casing  1 . Optical detecting members  71 A and  71 B are provided on the lower surface of the circuit board  70 . The optical detecting members  71 A and  71 B are both light receiving elements for receiving detection light. On the other hand, a second circuit board (not shown) is attached also to the bottom plate of the casing  1 , and optical detecting members as light emitting elements for emitting detection light are provided opposite to the optical detecting members  71 A and  71 B in the Z direction. 
     Detection holes are formed in positions opposite to the optical detecting members  71 A and  71 B in the movable guide unit  50 . A detection light is emitted from the light emitting element upwardly through the detection hole and received by the light receiving element. If the disk D does not shield the detection light between the light emitting element and the light receiving element, the optical detecting members  71 A and  71 B send an H-level output signal as a non-detection output. If the disk D shields the detection light, the light receiving element cannot receive light, and the optical detecting members  71 A and  71 B send an L-level output signal as a detection output. Other level output signals may be used as non-detection and detection outputs. 
     Here, the above light emitting element and light receiving element may change their positions. In other words, it is possible to form the optical detecting members  71 A and  71 B on the circuit board  70  using light emitting elements and form the optical detecting members on the second circuit board using light receiving elements. 
     Further, the optical detecting members  71 A and  71 B may be reflection type optical detecting members integrally equipped with a light emitting element and a light receiving element. In this case, detection light emitting from the light emitting element is reflected by the surface of the disk D and guided to the light receiving element to thereby detect the disk D. Here, the second circuit board can be omitted. 
     As shown in  FIG. 3 , the optical detecting members  71 A and  71 B are both provided between the transport roller  41  and the front plate  2  having the insertion port, the optical detecting member  71 B as a first optical detecting member is disposed closer to the front plate  2  than the optical detecting member  71 A as a second optical detecting member. 
     Provided that a line passing the rotation center of the turntable  23  and extending along the Y 1 -Y 2  direction is a conveyance center line Oa-Oa, the optical detecting members  71 A and  71 B are arranged away from each other on the left side (X 2  side) of the conveyance center line Oa-Oa. In addition, the optical detecting members  71 A and  71 B are arranged not to face a center hole Da of the disk D and its surrounding ring-shaped transport portion during insertion of the normal disk D having the diameter of 12 cm along the Y 2  direction. 
     As shown in  FIG. 3 , the optical detecting members  71 A and  71 B are placed at the same distance r 0  from the rotation center of the turntable  23 . In addition, as shown in  FIG. 6 , when the normal disk D is clamped to the turntable  23 , the optical detecting members  71 A and  71 B are both positioned just inside of the outer edge of the disk D on the insertion port side as well as just inside of the ring-shaped transparent portion generally formed around the outer edge of the disk D. 
     Thus, during a period from when the normal disk D was inserted from the insertion port to thereby switch output levels of the optical detecting members  71 A and  71  to L level corresponding to a detection state until when the disk D is transported in a normal way and adjusted to a normal installation end position where the center of the disk D is aligned with the rotation center of the turntable  23 , output levels of the optical detecting members  71 A and  71 B are kept at L level. 
     As shown in  FIG. 6 , a circuit board is further provided on an upper surface of the bottom plate of the casing  1 . A limit switch S 2  is provided on the X 1  side of the circuit board. An actuator Sb of the limit switch S 2  protrudes in the X 1  direction. 
     A contact portion (not shown) is formed on a lower surface of the reversing lever  47  for transmitting a movement force of the left-sided slider  30   b  to the right-sided slider  30   a . When the reversing lever  47  is turned clockwise on the support shaft  47   a  to let the right-sided slider  30   a  move farthest to the Y 1  side, the contact portion comes into contact with the actuator Sb of the limit switch S 2  to switch an output of the limit switch S 2  from OFF to ON. At this time, it is detected that the right-sided slider  30   a  and the left-sided slider  30   b  move farthest to the Y 1  side. A not-shown control circuit determines that a series of operations for installing the disk D has been completed and stops the motor M. 
     Next, an operation for transporting the disk D into the disk device and an operation for discharging the disk D from the insertion port will be described. 
       FIG. 7  is a flowchart showing an operation executed during a period from disk insertion from the insertion port until transport up to a clamp-enabled position. 
     In the flowchart of  FIG. 7 , each step is denoted by “ST”. 
     (Waiting for Disk Insertion) 
     As shown in  FIGS. 1 and 2 , in a standby state where the device waits for insertion of the disk D, the right-sided slider  30   a  and the left-sided slider  30   b  are both moved in the Y 2  direction. The lifting shaft  18  is lifted along the cam elongate hole  32   a  of the clamp control cam unit  32  provided to the right-sided slider  30   a , and then the clamp base  12  is turned clockwise and the damper  27  is lifted from the turntable  23 . 
     Further, the right end of the roller shaft  42  is guided to the upper guide portion  34   a  of the roller control cam unit  34  provided to the right-sided slider  30   a , and the transport roller  41  is biased to the stationary guide unit  43  by means of elastic force applied to the roller bracket  44  from the tension coil spring. In addition, the lifting guide portion  35   a  at the end of the right-sided slider  30   a  on the Y 1  side is away from the lifting projection  55 , and the movable guide unit  50  is turned clockwise and inclined to come into contact therewith. 
     In the standby state shown in  FIGS. 1 and 2 , no power is supplied to the transport motor. Further, although a detection voltage is applied to the detecting switch S 1 , a contact of the detecting switch S 1  is broken in a non-contact state and thus, no current flows through the detecting switch S 1 . In addition, no power is applied to the optical detecting members as light emitting elements facing the optical detecting members  71 A and  71 B. At this point of time, no detection light is emitted from the light emitting elements. 
     (Transport Operation) 
     In the standby state shown in  FIGS. 1 and 2 , when the disk D is inserted from the insertion port toward the Y 2  direction (ST 1 ), an outer peripheral portion of the disk D on the Y 2  side is guided between the guide surface  51  of the movable guide unit  50  and the guide surface  44   i  of the opposing guide portion  44   h . In the standby state, a distance between the guide surface  51  of the movable guide unit  50  and the guide surface  44   i  of the opposing guide portion  44   h  decreases toward the Y 2  side. Therefore, if the disk D is inserted up to a position (i) or (ii) in  FIG. 3 , the upper surface of the disk D lifts the movable guide unit  50  and the actuator Sa is lifted by the bottom portion of the recess  54  of the movable guide unit  50  to thereby switch an output of the detecting switch S 1  from OFF to ON. 
     In ST 2 , if a not-shown control circuit (control unit) disposed in the casing  1  determines that the output of the detecting switch S 1  is kept OFF, the processing advances to ST 3  and the device remains in the standby state shown in  FIGS. 1 and 2 . The not-shown control circuit (control unit) may be a circuit board including plural electronic devices or one electronic device (microcomputer). 
     In ST 2 , when the output of the detecting switch S 1  is switched from OFF to ON, the control circuit starts power supply to the optical detecting members as light emitting elements facing the optical detecting members  71 A and  71 B. From then on, a current is continuously supplied to the light emitting elements or an intermittent-pulsed current is supplied thereto, with the result that detection light is emitted at regular intervals of several ms to several tens of ms. Other regular and irregular intervals may be used. 
     A current is supplied neither to the optical detecting members  71 A and  71 B nor the optical detecting members as light emitting elements facing the optical detecting members  71 A and  71 B until the output of the detecting switch S 1  was switched to ON. A current is supplied only after the output of the detecting switch S 1  was switched to ON in response to insertion of the disk D or the like from the insertion port. Thus, power consumed during waiting for disk insertion can be saved. 
     In ST 4 , it is determined whether an output signal of the optical detecting member  71 A is kept at H level and an output signal of the optical detecting member  71 B is changed from H level to L level. 
     If the normal disk D having a round outer shape, not an irregular disk not having a round outer shape or a card, has been inserted, and the disk D is transported from the position (i) to the position (ii) in  FIG. 3 , the end portion of the disk D on the Y 2  side first shields detection light of the optical detecting member  71 B. At this point of time, detection light of the optical detecting member  71 A is not yet shielded. Thus, an output signal of the optical detecting member  71 B is changed from H level to L level, and an output signal of the optical detecting member  71 A is kept at H level. At this time, the control circuit determines that the disk D allowed to transport has been inserted, and advances to ST 5  and then, drives the transport motor to rotate the roller shaft  42  in the disk transport direction. 
     Here, in the case where the normal disk D having the diameter of 12 cm is inserted, after the detecting switch S 1  was switched to ON in ST 2 , only the optical detecting member  71 B may be switched to L level corresponding to a detection state as in ST 4  some time later. Alternatively, the following structure may be adopted. That is, when the detecting switch S 1  is switched to ON in ST 2 , the detection light of the optical detecting member  71  is already shielded by the disk D. If the condition for YES is satisfied in ST 2 , the condition for YES in ST 4  is accordingly satisfied. At this time, it is determined that the normal disk D is inserted. 
     Here, after the detecting switch S 1  was turned ON, and a current was supplied to the optical detecting members  71 A and  71 B and the optical detecting members as light emitting elements facing the optical detecting members  71 A and  71 B, if the output signal of the optical detecting member  71 B is not switched to L level, a current is continuously supplied to the optical detecting members  71 A and  71 B and the light emitting elements without driving the transport motor nor rotating the roller shaft  42 . Then, if the detecting switch S 1  is turned OFF, it is determined that no object is inserted from the insertion port, and current supply to the optical detecting members  71 A and  71 B is stopped. 
     Further, in ST 4 , if the output signal of the optical detecting member  71 B is kept at H level corresponding to a non-detection state and only the output signal of the optical detecting member  71 A on the back side is switched to L level, the control circuit determines that an object inserted from the insertion port is not a round disk and does not advance to ST 5  and rotate the roller shaft  42 . At this time as well, the control circuit waits until the detecting switch S 1  is turned OFF, and power supply to the optical detecting members  71 A and  71 B and the light emitting elements is stopped. 
     In other words, a positional relationship among the transport roller  41  and the optical detecting members  71 A and  71 B is determined such that at the time when the normal disk D is inserted from the insertion port in a normal way, and the outer edge of the disk D on the Y 2  side abuts against the transport roller  41 , while the output signal of the optical detecting member  71 B is switched to L level corresponding to a detection state, the output signal of the optical detecting member  71 A is not switched to the L level corresponding to the detection state. As a result, if the normal disk D is inserted in a normal way, the roller shaft  42  can be rotated. If any other irregular disk or card is inserted, the roller shaft  42  is not rotated and the irregular disk or card can be prevented from being transported into the device with more reliability. 
     Further, the optical detecting members  71 A and  71 B are arranged only on the left side (one side) of the conveyance center line Oa-Oa away from the center line. A large area is secured on the right side of the optical detecting member  71 B on the insertion port side, not occupied by the optical detecting members. For example, if a credit card or a foreign material like a card with a similar size to the credit card is inserted into the insertion port at a position nearer the right side (X 1  side) to turn the detecting switch S 1  ON, the optical detecting member  71 B is rarely switched to a detection state. If such a foreign material is inserted, the roller shaft  42  is not rotated and the processing does not shift to a transport operation. 
       FIG. 4  shows a disk D with a small diameter of 8 cm. Even if the small-diameter disk D 1  is inserted from the insertion port at a position nearer the right side, the optical detecting member  71 B is not shifted to a detection state and the transport motor can be prevented from operating. 
     In ST 5 , if the transport motor is driven to rotate the roller shaft  42  in the transport direction, an outer edge of the disk D on the Y 2  side is guided to a space between the transport roller  41  and the stationary guide unit  43 . Since an elastic force of the tension coil spring acts on the roller shaft  42 , the disk D is held between the transport roller  41  and the lower surface  43   a  of the stationary guide unit  43  and transported into the casing  1  by means of rotational force of the transport roller  41 . 
     If the control circuit (control unit) determines that the output signal of the optical detecting member  71 B is changed from H level to L level in ST 4 , the circuit starts a measurement timer to start measuring an elapsed time from when the condition for YES in ST 4  is satisfied. 
     In ST 6 , it is determined whether the output signal of the optical detecting member  71 A is switched to L level corresponding to the detection state while the optical detecting member  71 B remains in the detection state after the optical detecting member  71 B was shifted to the detection state. If the optical detecting member  71 B is not switched to L level within a predetermined period from when the time measurement was started, the control unit determines that an object other than the normal disk D is transported and advances to ST 7 . Then, the unit rotates the transport motor and the roller shaft  42  in a reverse direction and shifts to a discharge operation. 
     On the other hand, in ST 6 , if the output signal of the optical detecting member  71 A is not switched to L level within a predetermined period from when the time measurement was started, the transport roller  41  keeps rotating for the transport operation, and the control unit advances to ST 8 . 
     In a subsequent transport operation, if the normal disk having the diameter of 12 cm is transported in a normal way by means of rotational force of the transport roller  41 , neither the center hole of the normal disk D nor its surrounding ring-shaped transparent portion passes through positions opposite to the optical detecting members  71 A and  71 B, and the ring-shaped transparent portion around the disk D does not pass through positions opposite to the optical detecting members  71 A and  71 B. As shown in  FIG. 5 , if the disk D is adjusted to a normal installation position where the center of the normal disk D is aligned with the center of the turntable  23 , the optical detecting members  71 A and  71 B face a portion just inside of the ring-shaped transparent portion around the normal disk D. 
     Thus, when the normal disk D is being transported, as shown in  FIG. 5 , the output signals of the optical detecting members  71 A and  71 B are both kept at L level until the position of the disk D is adjusted. If at least one of the detection signal of the optical detecting members  71 A and  71 B is switched to H level corresponding to the non-detection state, the control circuit (control unit) determines that an object other than the normal disk D is being transported and reversely rotates the transport roller  41  to discharge the transported object from the insertion port. 
     More specifically, the control unit monitors whether the output signal of the optical detecting member  71 B is kept at the L level corresponding to the detection state in ST 8  or whether the output signal of the optical detecting member  71 A is kept at L level corresponding to the detection state. Then, if the conditions for YES are satisfied in ST 8  and ST 9 , the control unit determines that the normal disk D is being transported in a normal way. If the condition for YES is not satisfied in at least one of ST 8  and ST 9 , the processing immediately shifts to ST 7  to start a discharge operation. 
     Further, a distance r 0  from the rotation center of the turntable  23  to the optical detecting members  71 A and  71 B in  FIG. 3  is set to 4 cm or more. As shown in  FIG. 4 , if the small-diameter disk D 1  having the diameter of 8 cm is inserted, the optical detecting members  71 A and  71 B are not both switched to the detection state, and it is more likely that the condition for YES is not satisfied in ST 6 . Even if the condition for YES is satisfied in ST 6 , at the time when the center of the small-diameter disk D 1  approaches the turntable  23 , at least one of the optical detecting members  71 A and  71 B is switched to the non-detection state. Thus, the control unit immediately advances to ST 7  to discharge the small-diameter disk D 1 . 
     Likewise, if an irregular disk or card not having a round outer shape other than the small-diameter disk D 1  is inserted, the control unit is more likely to shift to the discharge operation in ST 7 . 
     If the normal disk D is further transported to the Y 2  direction from the state shown in  FIG. 4  and reaches the position shown in  FIG. 5 , the outer edge of the disk D on the Y 2  side presses the detection pin  14 A constituting the trigger member  14  toward the Y 2  direction to turn the arm  14 B counterclockwise. At the same time, the outer edge of the normal disk D abuts against the pair of stopper members  16   a ,  16   b  and the disk D is adjusted to the normal transport end position as the clamp-enabled position. 
     If the arm  14 B of the trigger member  14  is turned counterclockwise, the motor M is driven and in addition, a gear of a not-shown power transmitting mechanism is engaged. The left-sided slider  30   b  is moved to the Y 1  direction by a power of the motor M. Here, the following structure may be adopted. That is, the motor M doubles as the transport motor, and in ST 5 , the motor M is driven to rotate the roller shaft  42  and then, the power transmitting mechanism operates based on the rotational force of the arm  14 B in the state of  FIG. 5 , and the power of the motor M is transmitted from the power transmitting mechanism to the left-sided slider  30   b.    
     After that, the right-sided slider  30   a  and the left-sided slider  30   b  move from the position of  FIG. 5  toward the Y 1  direction in sync with each other. In this process, the lifting shaft  18  is guided downwardly along the cam elongate hole  32   a  of the clamp control cam portion  32  formed on the right-sided slider  30   a  in  FIG. 1  and moved to the clearance hole portion  32   b . Thus, the clamp base  12  is turned counterclockwise on the connecting shafts  13 ,  13  by means of basing force of the torsion coil spring  17  to move the damper  27  down to the turntable  23 . 
     At almost the same time as when the clamp base  12  is turned counterclockwise, the right end of the roller shaft  42  is guided from the upper guide portion  34   a  of the roller control cam unit  34  provided on the right-sided slider  30   a  to the inclined guide hole  34   c  and further restrained in the lower restraint portion  34   b . As a result, the roller bracket  44  is turned clockwise to move the roller shaft  42  and the transport roller  41  downward. The normal disk D placed on the transport roller  41  is moved downward together with the transport roller  41 , and the center hole Da of the disk D is held between the turntable  23  and the damper  27  to clamp the disk D. 
     After the transport roller  41  was restrained in a lower position away from the disk D by the lower restraint portion  34   b  of the roller control cam unit  34 , the right-sided slider  30   a  is further moved toward the Y 1  direction, the lifting projection  55  is lifted by the lifting guide portion  35   a  of the guide control cam unit  35  provided at the end of the right-sided slider  30   a  on the Y 1  side and held on the retention guide portion  35   b . As a result, the movable guide unit  50  is turned counterclockwise, and the guide surface  51  as the lower surface of the movable guide unit  5  is in a longitudinal attitude and then, the clamped disk D is lifted. 
     If the right-sided slider  30   a  is moved farthest to the Y 1  side to complete the operation of clamping the normal disk D as above, as shown in  FIG. 6 , the contact portion of the reversing lever  47  for driving the right-sided slider  30   a  comes into contact with the actuator Sb of the limit switch S 2 , and an output of the limit switch S 2  is switched from OFF to ON (ST 10  in  FIG. 7 ). The limit switch S 2  functions as a disk installation completion detecting switch for detecting that the disk D is clamped to the turntable  23 . 
     In the flowchart of  FIG. 7 , in ST 10 , the control unit monitors whether the limit switch S 2  is turned ON within a predetermined period from when the time measurement with the timer was started in ST 4 . If it is determined that the switch is turned ON within the predetermined period in ST 10 , the control unit advances to ST 11  and determines that disk installation is completed. In the state shown in  FIG. 6 , the disk D clamped to the turntable  23  can be rotated. 
     On the other hand, if the processing is not shifted from ST 4  to ST 10  within a predetermined period, the control unit determines that the disk is not clamped in a normal way and thus shifts to ST 7  for the discharge operation. 
     (Discharge Operation) 
     In the case of discharging the normal disk D after being rotated, the right-sided slider  30   a  and the left-sided slider  30   b  are moved in the Y 2  direction by the motor M to unclamp the disk D. In addition, the disk D is held between the transport roller  41  and the stationary guide unit  43  and discharged from the insertion port. 
     At this time, the control unit monitors the output signals of the optical detecting members  71 A and  71 B and then, if the output signal of the optical detecting member  71 A is switched to H level corresponding to the non-detection state within a predetermined period from the discharge operation, the motor is stopped. At this time, the normal disk D is moved a little from the position as indicted by the solid line in  FIG. 4  toward the Y 1  side and stopped there, and the outer edge of the disk D on the Y 2  side is held between the stopped transport roller  41  and the stationary guide unit  43 . 
     After that, if the disk D is taken off, the output signals of the optical detecting members  71 A and  71 B are shifted to H level corresponding to the non-detection state. The control unit determines that the disk D is taken off from the insertion portion when the movable guide unit  50  is turned clockwise and the detecting switch S 1  is turned OFF as well as the optical detecting members  71 A and  71 B are shifted to the non-detection state. Then, when the detecting switch S 1  is turned OFF, the control unit stops power supply to the optical detecting members  71 A and  71 B and the light emitting elements. Alternatively, after the elapse of a predetermined period from when the detecting switch S 1  is turned OFF, the control unit stops power supply to the optical detecting members  71 A and  71 B and the light emitting elements. 
     Next, if the control unit determines that the normal disk is not transported in a normal way and shifts to the discharge operation as in ST 7  of  FIG. 7 , the unit determines that disk transport is completed when a target object for discharge is separated from the transport roller  41 , the movable guide unit  50  is turned clockwise, and the detecting switch S 1  is turned OFF regardless of change in output signals of the optical detecting members  71 A and  71 B. Then, the control unit stops power supply to the optical detecting members  71 A and  71 B and the light emitting elements. 
     In the above embodiment, the movable guide unit  50  is provided rotatably on the support shafts  52 ,  52  in the disk thickness direction, and the detecting switch S 1  is turned ON in response to the rotation of the movable guide unit  50 . However, the present invention is applicable to such a structure that when the disk D is inserted, an insertion detecting pin or detecting slider is moved by the outer edge of the disk D to operate the detecting switch. 
     While there has been illustrated and described what is at present contemplated to be preferred embodiments of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made, and equivalents may be substituted for elements thereof without departing from the true scope of the invention. In addition, many modifications may be made to adapt a particular situation to the teachings of the invention without departing from the central scope thereof. Therefore, it is intended that this invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.