Abstract:
A disk apparatus has a slider cam, disk tray, and reproducing assembly. The slider cam has a cam groove. The slider cam moves between a first position and a second position, to retract a disk tray into the apparatus and extend from the apparatus, respectively. The reproducing assembly has a cam follower guided in the cam groove to move between a reproducing position and a non-reproducing position. The cam groove has first, second, and third grooves. The third groove connects the first and second grooves together. The first groove has a groove wall that extends substantially perpendicularly to the axis. The cam follower moves along the first groove to collide against the wall when a shock is given to the apparatus during transportation, thereby preventing the disk tray from popping out of the apparatus inadvertently.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a disk apparatus that performs the recording information on and reproducing information from a disk such as a CD and a DVD, and more particularly to a disk-loading mechanism that performs the loading and unloading of a disk as well as clamping and unclamping the disk with respect to the reproducing unit.  
           [0003]    2. Description of the Related Art  
           [0004]    {Construction} 
           [0005]    [0005]FIG. 9 is an exploded perspective view of a disk mechanism of a conventional disk apparatus.  
           [0006]    [0006]FIGS. 11 and 12 are top views of the disk apparatus of FIG. 9.  
           [0007]    FIGS.  13 A- 13 C are illustrative diagrams, illustrating the operation of the apparatus.  
           [0008]    Referring to FIG. 9, a loader base  21  includes sidewalls  21   c  and  21   d  opposing each other with a top table  21   a  disposed therebetween. A disk damper  21   b  is disposed at a predetermined position of the top table  21   a . The sidewalls  21   c  and  21   d  have guide rails, not shown, on which a disk tray  22  is slidingly supported such that the disk tray  22  can move back and forth on a Y-axis. The disk tray  22  has a disk-shaped recess in which a disk  23  is received and an opening  22   b  through which a reproducing unit  30  upwardly faces the disk  23 .  
           [0009]    [0009]FIG. 10 is a perspective view of a pertinent portion of the disk apparatus of FIG. 9.  
           [0010]    A slider cam holder  21   e  supports a slider cam  24  such that the slider cam  24  can slide back and forth on an X-axis. The slider cam  24  has an upright boss  24   a , a gear assembly  26 , and a loading motor  25 . The gear assembly  26  includes a pinion gear  26   b  and a wheel gear  26   a . The wheel gear  26   a  and the pinion gear  26   b  are rotatable about a Z-axis that passes through the wheel gear  25   a  and the pinion gear  26   b . The wheel gear  26   a  is in mesh with a worm gear  25   a  connected to a shaft of the loading motor  25 , so that when the loading motor  25  runs, the worm gear  25   a  transmits the rotation of the loading motor to the wheel gear  26   a . A worm-gear drive has a worm gear and a wheel gear in mesh with the worm gear. Many worm-gear drives are of the construction that rotation is transmitted from a worm gear to a wheel gear but not from the wheel gear to the worm gear. The term “self-lock” is used to cover this construction in this specification. Some worm-gear drives are of the construction that rotation is transmitted from a worm gear to a wheel gear and from the wheel gear to the worm gear. Whether a worm-gear drive is of a self-lock type depends on the combination of the lead angle and friction coefficient between the worm gear and the wheel gear. The worm gear  25   a  and wheel gear  26   a  form a non-self-lock type worm-gear drive, i.e., rotation can be transmitted bidirectionally between the worm gear  25   a  and the wheel gear  26   a . The non-self-lock type worm-gear drive is employed so that the user place, for example, a CD into the tray at the tray-open position and then pushes the tray into the reproducing unit. The shaft of the loading motor  25  is free to rotate when the loading motor  25  is not switched on.  
           [0011]    The slider cam  24  has a cam groove  27  formed in a side wall  24   b  that lies in a plane in which the X-axis and Z-axis lie. The cam groove  27  includes an upper horizontal groove  27   a , a lower horizontal groove  27   b , and an inclined groove  27   c  through which the upper horizontal groove  27   a  communicates with the lower horizontal groove  27   b.    
           [0012]    A lift arm  28  (FIG. 9) has a pair of pins  28   a  and  28   b  that project from the lift arm  28  outward in opposite directions and is in line with each other. The pins  28   a  and  28   b  loosely extend into holes  21   g  and  21   f  formed in the wall  21   d  and  21   c  of the loader base  21 , respectively, so that the lift arm  28  is pivotal about the pins  28   a  and  28   b . The lift arm  28  has a projection  28   c  that loosely fits into the cam groove  27  formed in the slider cam  24 .  
           [0013]    Referring back to FIG. 9, the reproducing unit  30  has coupling portions or screws  30   a ,  30   b , and  30   c  by which the reproducing unit  30  is assembled to the loader base  21 . The screw  30   a  supported on a support portion  21   h  of the loader base  21  through a damper  30   d . The screws  30   b  and  30   c  are coupled to support portions  28   d  and  28   e  on the lift arm  28  through dampers  30   e  and  30   f , respectively, such that the reproducing unit  30  is suspended from the lift art  28 . The reproducing unit  30  has primarily a turntable  30   g  and an optical pickup  30   h . The turntable  30   g  cooperates with the disk clamper  21   b  so that a disk is sandwiched between the disk damper  21   b  and the turntable  30   g.    
           [0014]    [0014]FIG. 11 illustrates the disk apparatus as seen on the Z-axis toward the origin (i.e., when seen from above). Referring to FIG. 11, the disk apparatus illustrated in FIG. 9 have been assembled such that the disk tray  22  is at a loading position and the reproducing unit  31  is at a later described reproducing position.  
           [0015]    A rack gear  22   c  is formed on the underside of the disk tray  22  and includes three portions: a linear side portion  22   d  that extends on the Y-axis along the side of the disk tray, a linear front portion  22   e , and a curved portion  22   f  that connects the linear side portion  22   d  and the linear front portion  22   e . There is provided a guide groove  22   g , which extends along the rack gear  22   c  and has a home portion  22   h  that is parallel to the linear front portion  22   e.    
           [0016]    The slider cam  24  is held on the loader base  21  under the disk tray  22  and is slidable on the X-axis. The pinion gear  26   b  of the slider cam  24  is in mesh with the rack gear  22   c , and the upright boss  24   a  extends into the guide groove  22   g  to slide along it.  
           [0017]    {Tray-Ejecting Operation} 
           [0018]    A tray-ejecting operation is performed to eject the disk tray  22  both when a disk is loaded prior to the reproduction of information from the disk and when the disk is unloaded after the reproduction of information.  
           [0019]    Referring to FIG. 11, the slider cam  24  has moved completely on the X-axis away from the origin so that the boss  24   a  is at the home portion  22   h.    
           [0020]    [0020]FIG. 13A illustrates the cam groove  27  formed in the slider cam  24  and the projection  28   c  of the lift arm  28  when they are seen on the Y-axis toward the origin.  
           [0021]    Referring to FIG. 13A, the lift arm  28  is at a position where the projection  28   c  is in the upper horizontal grooves  27   a . The turntable  30   g  of the reproducing unit  30  and the disk damper  21   b  cooperate to hold a disk sandwiched therebetween. In the specification, this state is referred to as a standby state of the disk apparatus.  
           [0022]    When the loading motor  25  is switched on to drive the pinion gear  26   b  in a direction shown by arrow A (FIG. 11) about the Z-axis, the rotation of the pinion gear  26   b  causes the slider cam  24  to move on the X-axis toward the origin. Thus, as shown in FIG. 13B, the cam engagement between the projection  28   c  and groove  27  causes the projection  28   c  to move along the inclined groove  27   c  toward the lower horizontal groove  27   b , so that the lift arm  28  slowly pivots in a direction shown by arrow C about the X-axis to depress the coupling sections  30   b  and  30   c . Thus, the reproducing unit  30  is tilted downward. The inclination of the reproducing unit  30  causes the turntable  30   g  to tilt downward so that the turntable  30   g  leaves the disk damper  21   b  to release the disk from the sandwiched engagement with the turntable  30  and the damper  21   b.    
           [0023]    The pinion gear  26   b  continues to rotate in the direction shown by arrow A, so that the slider cam  24  moves on the X-axis toward the origin and finally reaches a position shown in FIG. 13C where the projection  28   c  is in the lower horizontal groove  27   b  and therefore the reproducing unit  30  is at its maximum inclination. The reproducing unit  30  is supported at three dampers  30   d ,  30   e , and  30   f  that allow the reproducing unit  30  to incline smoothly.  
           [0024]    The pinion gear  26   b  further continues to rotate, so that the projection  28   c  of the lift arm  28  moves from the right end of the lower horizontal groove  27   b  to the left end.  
           [0025]    Shortly after the projection  218   c  reaches the position of FIG. 13C, the pinion gear  26   b  starts to move into meshing engagement with the curved portion  22   f  (FIG. 11) of the rack gear  22   c  of the slider cam  24 . When the pinion gear  26   b  moves along the curved portion  22   f , the rotation of the pinion gear  26   b  causes the slider cam  24  to move on the X-axis toward the origin while also causing the disk tray  22  to gradually move on the Y-axis toward the origin. The pinion gear  26   b  finally reaches the end of the curved portion  22   f  so that the slider cam  24  reaches the end of its moving path. However, the pinion gear  26   b  still continues to rotate in the direction shown by arrow A to enter meshing engagement with the linear portion of the rack gear  22   c  of the but the slider cam  24  no longer moves on the X-axis. Instead, the disk tray  22  is caused to move faster on the Y-axis toward the origin, i.e., outwardly of the apparatus. When the disk tray  22  has reached a predetermined unloading position, the loading motor  25  stops.  
           [0026]    When a disk such as a CD, DVD or the like is played, the disk is first placed in the recess  22   a  in the disk tray  22  that is at the unloading position. Then, the loading motor  25  is switched on to run in a revere direction such that the pinion gear  26   b  rotates in a direction shown by arrow B. The disk tray  22  moves on the Y-axis away from the origin, initiating the loading operation in which the operation of the apparatus takes place in a reverse order to the previously described unloading operation. When the disk tray  22  reaches the loading position, the slider cam  24  slides on the X-axis away from the origin to eventually enter the standby state, passing the positions shown in FIGS.  13 C, FIG. 13B, and FIG. 13A in order.  
           [0027]    When the disk apparatus of the aforementioned construction is transported, the respective sections of the apparatus are set to the standby state shown in FIG. 11 but no disk is loaded.  
           [0028]    When a shock in a direction parallel to the X-axis is given to the disk apparatus, the slider cam  24  also receives a shock in the same direction. The shock causes the slider cam  24  to move on the X-axis. Because the motor  25  is not switched on, it is free to rotate so that the pinion gear  26   b  rotates as the slider cam  24  moves on the X-axis. As shown in FIG. 13B, the projection  28   c  of the lift arm  28  moves into engagement with the inclined groove  27   c  formed in the slider  24 . If shocks are applied repeatedly in the same direction, the projection  28   c  moves on the Z-axis due to the cam engagement with the inclined groove  27   c  and the weight of the reproducing unit  30 . As a result, the projection  28   c  eventually moves into engagement with the lower horizontal groove  27   b  as shown in FIG. 13C to finally abut the left end of the lower horizontal groove  27   b.    
           [0029]    As described above, the lift arm  28  rotates in the direction shown by arrow C, so that the reproducing unit  30  is inclined to cause the turntable  30   g  to leave the disk damper  21   b  downward. With this condition, when a shock is given in the direction of the Y-axis toward the origin, the disk tray  22  will move out of the loading position and the apparatus may be damaged during transportation.  
         SUMMARY OF THE INVENTION  
         [0030]    The present invention was made in view of the aforementioned drawbacks.  
           [0031]    An object of the invention is to provide a disk-apparatus in which-a disk tray is prevented from moving from a disk loading position to disk-unloading position, i.e., popping out of the apparatus during the transportation of the apparatus.  
           [0032]    A disk apparatus has a slider cam, a disk tray, and a reproducing assembly. The slider cam is movable on a first axis back and forth between a first position and a second position, said slider cam having a cam groove. The disk tray is movable on a second axis perpendicular to the first axis between a third position (disk-loading position) and a fourth position (disk-unloading position). The slider cam is at the third position when the disk tray is at the first position and at the fourth position when the disk tray is at the second position. The reproducing assembly has a cam follower. The cam follower is guided in the cam groove such that said reproducing assembly is at a reproducing position when said slider cam is at the first position and at a non-reproducing position when said slider cam is at the second position. The cam groove includes a first portion, a second portion, and a third portion. The first portion extends substantially parallel to the axis. The second portion extends substantially parallel to the axis. The third portion communicates with a first longitudinal end portion of the first portion and a second longitudinal end portion of the second portion to form a path of the cam follower at an obtuse angle with the first and second portions. The first longitudinal end portion has a groove wall that extends substantially perpendicularly to the axis.  
           [0033]    The first portion has a first longitudinal end and a second longitudinal end and the second portion has a third longitudinal end and a fourth longitudinal end. The third portion may communicates with the first portion between the first and second longitudinal ends and with the second portion between the third and fourth longitudinal ends to form a path of the cam follower at an obtuse angle with the first and second portions.  
           [0034]    The cam groove extends in a plane perpendicular to the second axis.  
           [0035]    The cam follower is in the first portion when said slider cam is at the first position and in the second portion when said slider cam is at the second position.  
           [0036]    Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0037]    The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limiting the present invention, and wherein:  
         [0038]    [0038]FIG. 1 is an exploded view illustrating a first embodiment of a disk apparatus according to the invention;  
         [0039]    [0039]FIG. 2 is a perspective view illustrating a pertinent portion of the disk apparatus;  
         [0040]    [0040]FIG. 3 is a top view of the disk apparatus;  
         [0041]    FIGS.  4 A- 4 C illustrate the operation of the disk apparatus;  
         [0042]    [0042]FIG. 5 illustrates a slider cam  5  according to the second embodiment;  
         [0043]    [0043]FIG. 6 is a top view of the disk apparatus as seen in a direction of the Z-axis when the apparatus is at the standby position;  
         [0044]    FIGS.  7 A- 7 D illustrate the projection  28   c  that moves along the cam groove  2 ;  
         [0045]    [0045]FIGS. 8A and 8B illustrate inclined upper horizontal grooves  2   a  and  6   a.    
         [0046]    [0046]FIG. 9 is an exploded perspective view of a disk-loading mechanism of a conventional disk apparatus;  
         [0047]    [0047]FIG. 10 is a perspective view of a pertinent portion of the disk apparatus of FIG. 9.  
         [0048]    [0048]FIGS. 11 and 12 are top views of the disk apparatus of FIG. 9; and  
         [0049]    FIGS.  13 A- 13 C are illustrative diagrams, illustrating the operation of the apparatus. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0050]    The present invention will be described in detail by way of example.  
         [0051]    First Embodiment  
         [0052]    [0052]FIG. 1 is an exploded view, illustrating a first embodiment of a disk apparatus according to the invention.  
         [0053]    [0053]FIG. 2 is a perspective view illustrating a pertinent portion of the disk apparatus. FIG. 3 is a top view of the disk apparatus.  
         [0054]    FIGS.  4 A- 4 C illustrate the operation of the disk apparatus.  
         [0055]    Structural elements similar to those in FIG. 9 have been given the same reference numerals and the description thereof is omitted. The following description will be focussed on only those different from FIG. 9.  
         [0056]    Throughout the figures, a disk tray  22  moves on a Y-axis and a disk  23  is placed in a plane in which an X-axis extends and is perpendicular to the Y-axis.  
         [0057]    Referring to FIG. 2, a slider cam  1  has a side wall  1   b  that lies in a plane in which the X-axis and Z-axis lie. The side wall  1   b  has a cam groove  2  formed therein. The cam groove  2  includes an upper horizontal groove  2   a , a lower horizontal groove  2   b , and an inclined groove  2   c . The inclines groove  2   c  is provided at an obtuse angle with the upper horizontal groove  2   a  and the lower horizontal groove  2   b  to form a path of a projection  28   c , and communicates with the upper horizontal groove  2   a  and the lower horizontal groove  2   b . The upper horizontal groove  2   a  has a collision section  2   d  at its one longitudinal end that connects to the incline groove  2   c . It is to be noted that the collision section  2   d  extends substantially perpendicular to the direction of the upper horizontal groove  2   a.    
         [0058]    When the disk apparatus is loaded with and the disk is unloaded from the disk apparatus, the disk apparatus operates in exactly the same way as the conventional disk apparatus of FIG. 9. However, the disk apparatus according to the first embodiment responds to shocks encountered during transportation in a way different from the conventional apparatus. Thus, the following description will be focussed on the manner in which the first embodiment responds to mechanical shocks.  
         [0059]    When the disk apparatus according to the first embodiment is transported, the respective sections of the apparatus are set to corresponding standby positions.  
         [0060]    [0060]FIG. 3 is a top view of the apparatus when it is seen in a direction of the Z-axis toward the origin, illustrating the positions of the respective sections of the apparatus at the standby positions.  
         [0061]    FIGS.  4 A- 4 C illustrate a projection  28   c  that moves along the cam groove  2 .  
         [0062]    [0062]FIG. 4A shows the disk apparatus when it is at the standby state.  
         [0063]    When a shock resulting from, for example, drop is applied to the apparatus in the direction of the Z-axis toward the origin, the slider cam  1  is caused to move in the same direction so that a pinion gear  26   b  in mesh with a rack gear  22   c  rotates.  
         [0064]    At this moment, a collision section  2   d  formed on the slider cam  1  collides against the projection  28   c  of a lift arm  28  as shown in FIG. 4B.  
         [0065]    Due to the fact that the slider cam  1  is moved by a shock, the collision section  2   d  collides against the projection  28   c  at a high speed as shown in FIG. 4B. As a result, the projection  28   c  repels the slider cam  1  toward the origin. In this manner, every time a shock is given to the apparatus in the direction of the X-axis, the projection  28   c  moves back and forth in the horizontal groove  2   a.    
         [0066]    The limited movement of the slider cam  1  allows the boss la of the slider cam  1  to stay within the home portion  22   h  of the guide groove  22   g  (FIG. 3). Thus, even when a shock is exerted on the slider cam in a direction of the Y-axis toward the origin, the disk tray  22  will not project outward beyond the loading position where the disk tray  22  remains in the apparatus.  
         [0067]    As described above, according to the first embodiment, the movement of the slider cam  1  due to external shocks during, for example, transportation is restricted so that the reproduction unit stays at the standby state.  
         [0068]    Second Embodiment  
         [0069]    A disk apparatus according to a second embodiment differs from that of the first embodiment in the shape of a cam groove formed in a slider cam.  
         [0070]    [0070]FIG. 5 illustrates a slider cam  5  according to the second embodiment. The second embodiment will now be described with reference to FIGS.  7 A- 7 D in terms of the structure and operation related to the slider cam  5  and the other parts of structure and operation are omitted.  
         [0071]    A vertical wall  5   b  of the slider cam  5  is formed with a cam groove  6  therein. The cam groove  6  includes an upper horizontal groove  6   a , a lower horizontal groove  6   b , and an inclined groove  6   c . The inclined groove  6   c  communicates with a mid way portion of the upper horizontal groove  6   a , thereby dividing the upper horizontal groove  6   a  into a normal guide portion  6   d  and a buffer guide portion  6   e.    
         [0072]    When a disk is loaded and unloaded, the disk apparatus operates in the same way as the conventional disk of FIG. 9 and therefore the description thereof is omitted. The second embodiment operates much the same way as first embodiment except when shocks are exerted on the apparatus during transportation. Thus, the description will be given of the operation of the second embodiment when shocks are exerted during transportation.  
         [0073]    [0073]FIG. 6 is a top view of the disk apparatus as seen in the direction of the Z-axis when the apparatus is at the standby position.  
         [0074]    When the disk apparatus according to the second embodiment is transported, the respective sections of the apparatus are set to their standby positions. When a shock is given to the disk apparatus in the direction of the X-axis toward the origin, the slider cam  25  is caused to move in the same direction so that the pinion gear  26   b  rotates.  
         [0075]    Thus, as shown in FIG. 7B, the slider cam  5  moves such that the projection  28   c  of the lift arm  28  moves into the buffer guide portion  6   e  of the upper horizontal groove  6   a . FIGS.  7 A- 7 D illustrate the projection  28   c  that moves along the cam groove  2 . FIG. 7A shows the disk apparatus when it is at the standby state.  
         [0076]    As shown in FIG. 7C, if shocks are applied repeatedly in the direction of the X-axis toward the origin, the end  6   f  of the buffer guide portion  6   e  of the upper horizontal groove  6   a  collides against the projection  28   c  of the lift arm  28 . The shock exerted on the slider cam  5  causes the end  6   f  to collide against the projection  28   c  at a high speed. The projection  28   c  repels the slider cam  5  in the direction of the X-axis away from the origin to the position of FIG. 7D where the projection  28   c  is again in the buffer guide portion  6   e . In this manner, every time a shock is exerted in the direction of the X-axis, the slider cam  5  moves back and forth such that the projection  28   c  reciprocates in the upper horizontal groove  6   a  relative to the slider cam  5 .  
         [0077]    As described above, according to the second embodiment, the movement of the slider cam  5  due to external shocks during, for example, transportation is restricted so that the reproduction unit remains held at the standby state.  
         [0078]    The limited movement of the slider cam  5  allows the boss la of the slider cam stays within the home portion  22   h  of the guide groove  22   g  (FIG. 6). Thus, even when a shock is exerted on the slider cam in the direction of the Y-axis toward the origin, the disk tray  22  will not project outward beyond the loading position where the disk tray  22  is retracted in the apparatus.  
         [0079]    The aforementioned embodiments have been described in terms of a cam groove formed in the slider cam and a projection that is provided on the lift arm and engages the cam groove. Instead, the cam groove may be formed in the lift arm and the projection may be formed on the slider cam and engage the cam groove.  
         [0080]    Modification of Cam Groove  
         [0081]    [0081]FIGS. 8A and 8B illustrate inclined upper horizontal grooves  2   a  and  6   a . In the aforementioned embodiments, the upper horizontal groove  2   a  and upper horizontal groove  6   a  extend in the direction of the X-axis. The upper horizontal groove  2   a  and upper horizontal groove  6   a  may be inclined slightly so that the projection  28   c  slides down away from the collision section  2   d  and the end  6   f  due to the weight of the reproducing unit  30 . Referring to FIGS. 8A and 8B, the upper horizontal groove  2   a  and upper horizontal groove  6   a  extend in a direction shown by arrow E that makes an angle  0  with a horizontal line H. This construction allows the projection  28   c  to stay at or return to an end portion opposite to the collision section  2   a  or the end  6   f.    
         [0082]    The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art intended to be included within the scope of the following claims.