Abstract:
An optical disk drive with anti-swing tray and method thereof. In order to reduce swing of the tray of the optical disk drive when the tray is opened, a first driving signal is applied to a driving module of the optical disk drive to move the tray from a first position to a second position. A calibrating signal is then applied over a predetermined time period to the driving module to correct the position of the tray.

Description:
BACKGROUND  
       [0001]     The invention relates to a short optical disk drive, and in particular to a short optical disk drive with a horizontal anti-swing tray.  
         [0002]      FIG. 1A  is a perspective view of a conventional optical disk drive. In  FIG. 1A , the conventional optical disk drive  10  has a main body  11  and a tray  12 . The tray  12  has a recess  13  for receiving optical disks. The main body  11  of the optical disk drive  10  has a carrier  14  and a driving module  17 . A spindle motor  15  and a pickup head  16  are disposed on the carrier  14 . The driving module  17  comprises a motor  171  and a gear assembly  172  to drive the tray  12 . After the driving module  17  moves the tray  12  holding an optical disk into the main body  11  and lifts the carrier  14 , the spindle motor  15  rotates the optical disk, and data is read therefrom or written thereto by the pickup head  16 .  
         [0003]      FIG. 1B  shows a conventional optical disk drive with the tray ejected. In  FIGS. 1A and 1B , the tray  11  of the optical disk drive  10  comprises a rack  121  on one side of the reverse surface. The motor  171  is capable of driving the tray  12  on one side through the gear assembly  172  and the rack  121 . The other side of the tray  12  is passively moved, such that sufficient gaps between the tray  12  and main body  11  are required to ensure the tray  12  can be moved smoothly.  
         [0004]     The left side of the tray  12  moves faster than the right side (passive side) because the tray  12  is driven by the driving module  17  on the left side (active side) when ejected. Thus, the tray  12  tilts rightward by a small angle as shown in  FIG. 2A  during ejection. When the motor  171  reverses to receive the tray  12 , the left side of the tray  12  is immediately inserted, but the right side of the tray  12  remains motionless. Thus, the tray  12  swings leftward by a small angle as shown in  FIG. 2B  when inserted.  
         [0005]     A sufficient portion of the tray  12  remains in the main body  11  when the tray  12  is open because the main body  11  and tray  12  of a conventional optical disk drive  10  are longer enough. The tilt angle of the tray  12  is very small, such that the horizontal swing problems described above are not apparent in conventional optical disk drives.  
         [0006]     Currently, optical disk drives are, however, shortened to reduce required space in device housings. Only a short portion of the tray remains in the main body when the tray is open because the main body and tray of a conventional short optical disk drive are shortened. Thus, the gap between the tray and main body at the passive side is magnified, causing the tray to tilt rightward by a relatively larger angle, increasing jitter and noise when closing the tray.  
       SUMMARY  
       [0007]     An embodiment of the invention provides a method for reducing the tray swing of a short optical disk drive when the tray is opened.  
         [0008]     Accordingly, in order to reduce swing of the tray of an optical disk drive when the tray is opened, a first driving signal is applied to a driving module of the optical disk drive to move the tray from a first position to a second position. A reverse second driving signal is then applied to the driving means over a predetermined time period to correct the position of the tray when the tray arrives in the second position.  
         [0009]     An optical disk drive of an embodiment of the invention comprises a tray, driving means, and control module. The driving means comprising a motor and a gear assembly moves the tray between a first position and a second position. The control module comprising a microprocessor  291  provides a first driving signal to the driving means to drive the tray from a first position to a second position, and provides a reverse second driving signal to the driving means over a predetermined time period to correct the position of the tray when the tray arrives in the second position.  
         [0010]     The optical disk drive further comprises a switch to determine the position of the tray. The tray is received in the optical disk drive when the tray is in the first position, and is opened when the tray is in the second position. The motor rotates in a first direction while the first driving signal is applied, and rotates in a reverse second direction while the calibrating signal is applied. The first driving signal is between 4 and 6V. The reverse second driving signal is between 3 and 5V. The predetermined time period is between 0.1 and 0.5 seconds. 
     
    
     BRIEF DESCRIPTION  
       [0011]     The present invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings which are given by way of illustration only, and thus are not limitation of the present invention, and wherein:  
         [0012]      FIG. 1A  is an exploded perspective view of a conventional optical disk drive;  
         [0013]      FIG. 1B  is a top view of a conventional optical disk drive when the tray is open;  
         [0014]      FIG. 2A  is a schematic view of the conventional optical disk drive when the tray is ejected;  
         [0015]      FIG. 2B  is a schematic view of the conventional optical disk drive when the tray is inserted;  
         [0016]      FIG. 3A  is an exploded perspective view of a short optical disk drive of an embodiment of the invention;  
         [0017]      FIG. 3B  is a top view of the tray of  FIG. 3A ; and  
         [0018]     FIGS.  4 A˜ 4 D shows the positions of the switch of the short optical disk drive when the tray is ejected. 
     
    
     DETAILED DESCRIPTION  
       [0019]      FIG. 3A  shows a short optical disk drive of an embodiment of the invention. In  FIG. 3A , the optical disk drive  20  has a main body  21  and a tray  22 . The length of the main body is between 160 and 190 mm, shorter than that of a conventional optical disk drive (190˜200 mm), to reduce required space. In  FIG. 3A , the tray  22  has a recess  23  for receiving optical disks. The main body  21  of the optical disk drive  20  has a carrier  24  and a driving module  27 . A spindle motor  25  and a pickup head  26  are disposed on the carrier  24 . The driving module  27  comprises a motor  271 , gear assembly  272 , and belt  273  to drive the tray  22 . After the driving module  27  moves the tray  22  holding an optical disk into the main body  21  and lifts the carrier  24 , the spindle motor  25  rotates the optical disk, and data is read therefrom or written thereto by the pickup head  26 .  
         [0020]      FIG. 3B  is a top view of the tray of  FIG. 3A . In  FIGS. 3A and 3B , the tray  21  of the optical disk drive  20  comprises a rack  221  on one side of the reverse surface. The motor  271  is capable of driving the tray  12  on one side through the gear assembly  272 , belt  273 , and rack  221 . A switch  28  is disposed on the front of the main body  21  and is capable of determining the relative position of the tray  22  with respect to the main body  21 . The tray  22  further comprises a track  222  on the reverse surface corresponding to the position of the switch  28 . The track  222  is utilized to pull a protrusion  281  of the switch  28  into different operating positions when the tray  22  is ejected or inserted. Thus, the position of tray  22  can be determined according to status of the switch  28 .  
         [0021]     FIGS.  4 A˜ 4 D shows the positions of the switch of the short optical disk drive when the tray is ejected. The optical disk drive further comprises a control module  29 . The control module  29  comprises a printed circuit board (PCB) and a microprocessor  291  disposed thereon. The switch  28  and motor  27  are separately connected to the PCB through wires or flexible printed circuit boards. The control module  29  of the optical disk drive can determine whether the tray  22  is in the first position, second position, or moving therebetween. The control module  29  also provides predetermined control signals of rotation direction, rotation rate, and duration to the motor  27 .  
         [0022]     In  FIGS. 3A and 4A , when the tray is received in the optical disk drive  20 , or the first position, and is going to be opened, the protrusion  281  of the switch  28  is restricted to a right position (first operating mode) by the track  222  of the tray  22 . The microprocessor  291  of the control module  29  provides a first driving signal, or a positive bias, to the motor  271 . The motor  271  rotates in a first direction V 1  and drives the tray  22  to open via the gear assembly  272  and rack  221 . In  FIG. 4B , as the tray  22  moving, the protrusion  281  of the switch  28  enters a middle section of the track  222  and restricted to a center position (second operating mode) The microprocessor  291  provides a larger first driving signal, or a larger positive bias, to the motor  271  according to the status of the switch  28 , maintaining movement of the tray  22 . The left side (active side) of the tray  22  moves faster than the right side (passive side) thereof because the tray  22  is only driven by the motor  271  on the left side. Thus, the tray  22  tilts rightward by a small angle as shown in  FIG. 4B .  
         [0023]     The microprocessor  291  stops the first driving signal when the tray  22  arrives at the second position as shown in  FIG. 4C . The motor  271 , however, still rotates for a short time period due to inertia, such that the protrusion  281  of the switch  28  will enter a third section of the track  222  and restricted to a left position (third operating mode). Simultaneously, the microprocessor  291  provides a calibrating signal, such as a reverse second driving signal, to the motor  271  and reverses the motor  271  for a predetermined time period. The left side of the tray  22  is inserted by a short distance during this reversing operation, and the tray  22  will swing leftward by a small correcting angle to the position as shown in  FIG. 4D .  
         [0024]     In some embodiments of the invention, the motor  271  rotates in a first direction V 1  while the first driving signal is applied, and rotates in a reverse second direction V 2  while the calibrating signal is applied. The first driving signal is between 4 and 6V. The reverse second driving signal is between 3 and 5V. The predetermined time period is between 0.1 and 0.5 second.  
         [0025]     The control module  29  of the short optical disk drive  20  provides a calibrating signal when the tray  22  is opened to correct the horizontal tilt angle thereof. The horizontal swing problem is not apparent in the short optical disk drive  20  because the correcting operation proceeds immediately after ejection of the tray  22 , and the swing angle is reduced when the tray  22  is inserted.  
         [0026]     While the invention has been described by way of example and in terms of the preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.