Patent Publication Number: US-2006020952-A1

Title: Optical control apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
      This application claims the priority benefit of Taiwan application serial no. 93121703, filed Jul. 21, 2004.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to an optical control apparatus and disc selecting method. More particularly, the present invention relates to an optical control apparatus and disc selecting method for a disc drive.  
      2. Description of the Related Art  
      Optical disc is a storage medium that has many advantages over the conventional magnetic storage medium. Optical discs have a high storage capacity and are easy to handle, and the data recorded in optical discs can be safely stored for a long time. Most important of all, the optical discs are relatively cheap to manufacture. In the past, each disc drive is designed to accommodate a single optical disc only. Thus, if a user needs to reproduce data from another optical disc, the disc inside the disc drive has to be manually replaced. To minimize the amount of manual disc swapping, disc drives that can hold numerous optical discs at the same time have been developed.  
       FIG. 1  is a diagram showing the layout of components inside a conventional multi-disc drive. To simplify the explanations, the major components inside the multi-disc drive are shown in block format. As shown in  FIG. 1 , a conventional disc drive  100  comprises a disc cassette  110 , an optical pick-up module  120 , a disc selecting mechanism  130  and a detecting unit  140 . The disc selecting mechanism  130  is adapted to operate within an operating space. The disc cassette  110  and the optical pick-up module  120  are disposed within the operating space of the disc selecting mechanism  130 . The disc cassette  110  is designed to accommodate a plurality of optical discs. The disc selecting mechanism  130  is designed to transfer an optical disc from the disc cassette  110  to the optical pick-up module  120  or return the optical disc inside the optical pick-up module  120  back to the disc cassette  110 . It should be noted that the disc selecting mechanism  130  must be raised or lowered to a suitable height level in the disc selection process before a required optical disc can be grasped. The disc selecting mechanism  130  is controlled by an output of the detecting unit  140  when moving to a predetermined height level.  
       FIG. 2A  is a perspective view showing a portion of the structure of a conventional disc drive. As shown in  FIGS. 1 and 2 A, a conventional disc drive  100  has a control module  150 , a driving motor  162  and a gear set  164  designed for moving the disc selecting mechanism  130  to a predetermined height level so that a particular optical disc can be grasped. The driving motor  162  drives the disc selecting mechanism  130  and an optical meter  144  through the gear set  164  simultaneously. The control module  150  is used for controlling the driving motor  162 .  
       FIG. 2B  is a perspective view showing the structure of a detecting unit inside a conventional disc drive. As shown in  FIG. 2B , the detecting unit  140  mainly comprises an optical sensor  142  and an optical meter  144 . The optical meter  144  has a plurality of indentations  144   a  that facilitate the optical sensor  142  to detect any movement in the optical meter  144 . It should be noted that the height of the disc selecting mechanism  130  could be derived from the amount of movement in the optical meter  144  because the driving motor  162  drives the disc selecting mechanism  130  and the optical meter  144  simultaneously through the gear set  164 . In the following, the structure and function of the detecting unit  140  is explained in more detail.  
       FIG. 3A  is a diagram showing an optical meter in a position to block a light beam emitted from an optical sensor.  FIG. 3B  is a diagram showing an optical meter in a position to allow the passage of a light beam emitted from an optical sensor. As shown in  FIGS. 3A and 3B , the optical sensor  142  comprises a light-emitting portion  142   a  and a light-detecting portion  142   b . The light-emitting portion  142   a  is adapted to emit a beam of light  142   c  to the light-detecting portion  142   b . The optical meter  144  is disposed between the light-emitting portion  142   a  and the light-detecting portion  142   b . As shown in  FIG. 3A , when the optical meter  144  blocks the light beam  142   c  emitted from the light-emitting portion  142   a , the light-detecting portion  142   b  detects the absence of the light beam  142   c . Hence, the driving motor  162  continues to drive the disc selecting mechanism  130  (shown in  FIG. 1 ). When the optical meter  144  moves to a position where the light beam  142   c  is able to pass through an indentation  144   a  and reach the light-detecting portion  142   b  as shown in  FIG. 3B , the optical sensor  142  outputs an electrical signal to the control module  136 . According to the electrical signal generated by the optical sensor  142 , the control module  150  is able to stop the driving motor  162  so that the disc selecting mechanism  130  is stationed at a suitable height level.  
      The number of indentations  144   a  in the optical meter  144  typically corresponds with the number of optical discs that can be stored inside the disc cassette  130 . In other words, the number of indentations  144   a  and the length of the optical meter  144  are directly proportional to the disc storage capacity of the disc cassette  110 . However, a long optical meter severely limits the reduction of size of the disc drive. Furthermore, if the number of optical discs designed to store inside the disc cassette  110  is changed, a different optical meter  144  is required to provide a correct disc selection. Therefore, disc drives designed to hold a different number of optical discs cannot use standardized optical meters  44  having a common configuration.  
     SUMMARY OF THE INVENTION  
      Accordingly, the present invention is directed to provide an optical control apparatus for controlling the operation of a disc selecting mechanism so that the optical control apparatus requires a smaller operating space.  
      As embodied and broadly described herein, the invention provides an optical control apparatus for a disc driver. The disc driver comprises a disc selecting mechanism, a driving module, a control module, a disc cassette and a data processing module. The disc selecting mechanism is suitable to operate in an operating space. The disc cassette and the data processing module are disposed within the operating space. The control module controls the driving module, and the driving module drives the disc selecting mechanism. The optical control apparatus comprises an optical sensor and a plate. The optical sensor is electrically connected to the control module. The optical sensor is designed to emit a light beam and detect the light beam. In addition, the plate and the disc selecting mechanism are driven by the driving module simultaneously, and the plate is driven by the control module to rotate. At least a portion of the plate is disposed on the optical path of the light beam produced by the optical sensor. The plate has at least one detecting region. After the plate has rotated a predetermined angle, the optical sensor is able to detect the detecting region.  
      According to one embodiment of the present invention, the angle of rotation of the plate can be 360°, 180°, 120°, 90°, 72° or 60°, for example.  
      According to one embodiment of the present invention, the optical sensor comprises a light-emitting portion and a light-detecting portion disposed at each side of the plate and the detecting region is a transparent region, for example. Furthermore, the transparent region comprises at least a through hole. In another embodiment, the detecting region is an opaque region. In yet anther embodiment, the plate further comprises a non-detecting region and the detecting region is a protrusion from the edge of the non-detecting region.  
      According to one embodiment of the present invention, the optical sensor comprises a light-emitting portion and a light-detecting portion disposed at the same side of the plate and the detecting region is a reflecting region, for example. In another embodiment, the detecting region is a non-reflecting region. In yet anther embodiment, the plate further comprises a non-detecting region and the detecting region is a protrusion from the edge of the non-detecting region.  
      According to one embodiment of the present invention, the driving module comprises a gear set and a driving motor. The driving motor drives the plate and the disc selecting mechanism simultaneously through the gear set, and the control module controls the driving motor.  
      The present invention provides an alternative optical control apparatus for a disc drive. The disc drive comprises a disc selecting mechanism, a driving module, a control module, a disc cassette and a data processing module. The disc selecting mechanism is suitable to operate in an operating space. The disc cassette and the data processing module are disposed within the operating space of the disc selecting mechanism. The control module controls the driving module and the driving module drives the disc selecting mechanism. The optical control apparatus comprises an optical sensor and a light-blocking element. The optical sensor is electrically connected to the control module. The optical sensor is designed to emit a light beam and detect a returning light beam. In addition, the light-blocking element and the disc selecting mechanism are driven by the driving module simultaneously. The light-blocking element is driven by the driving module to rotate around a spin axle. The optical sensor is disposed on the moving path of the light-blocking element such that the light-blocking element can pass the optical path of the light beam produced by the optical sensor. The light-blocking element has a detecting region such that the optical sensor can detect the detecting region.  
      According to one embodiment of the present invention, the optical sensor comprises a light-emitting portion and a light-detecting portion. The detecting region of the light-blocking element is permitted to pass through a space between the light-emitting portion and the light-detecting portion of the optical sensor. In addition, the detecting region is an opaque region, for example.  
      According to one embodiment of the present invention, the optical sensor comprises a light-emitting portion and a light-detecting portion. Furthermore, the detecting region comprises a reflecting region for reflecting the light beam back to the light-detecting portion.  
      In brief, the present provides an optical control apparatus having a plate and an optical sensor or a light-blocking element and an optical sensor. Since the optical control apparatus occupies a small operating space and does not depend on the number of optical discs that can be stored inside the disc cassette, an identical size plate or light-blocking element can be used in any disc drive with a disc cassette having whatever disc storage capacity.  
      It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.  
       FIG. 1  is a diagram showing the layout of components inside a conventional multi-disc drive.  
       FIG. 2A  is a perspective view showing a portion of the structure of a conventional disc drive.  
       FIG. 2B  is a perspective view showing the structure of a detecting unit inside a conventional disc drive.  
       FIG. 3A  is a diagram showing an optical meter in a position to block a light beam from an optical sensor.  
       FIG. 3B  is a diagram showing an optical meter in a position to allow the passage of a light beam from an optical sensor.  
       FIG. 4A  is a diagram showing the layout of components inside a multi-disc drive according to a first embodiment of the present invention.  
       FIG. 4B  is a diagram showing the disc selecting mechanism according to one embodiment of the present invention.  
       FIG. 5A  is a perspective view showing the optical control apparatus according to the first embodiment of the present invention.  
       FIG. 5B  is a diagram showing a plate blocking the light beam emitted from an optical sensor according to the present invention.  
       FIG. 5C  is a diagram showing a plate permitting the passage of a light beam emitted from an optical sensor according to the present invention.  
       FIG. 6  is a top view of an optical control apparatus according to a second embodiment of the present invention.  
       FIG. 7  is a perspective view of an optical control apparatus according to a third embodiment of the present invention.  
       FIG. 8  is a top view of an optical control apparatus according to a fourth embodiment of the present invention. 
    
    
     DESCRIPTION OF THE EMBODIMENTS  
      Reference will now be made in detail to the present embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.  
       FIG. 4A  is a diagram showing the layout of components inside a multi-disc drive according to a first embodiment of the present invention.  FIG. 4B  is a diagram showing the disc selecting mechanism according to one embodiment of the present invention. As shown in  FIGS. 4A and 4B , the optical control apparatus  300  is inside a disc drive  200  that comprises at least a disc selecting mechanism  210 , a driving module  220 , a control module  230 , an optical disc storage cassette  240 , and a data processing module  250 . The disc selecting mechanism  210  is suitable to operate in an operating space. The optical disc storage cassette  240  and the data processing module  250  are disposed within the operating space of the disc selecting mechanism  210 . The driving module  220  drives the disc selecting mechanism  210  to swap optical discs, and the control module  230  controls the driving module  210 . In addition, the driving module  220  comprises a driving motor  222  and a gear set  224 . The driving motor  222  drives the disc selecting mechanism  220  through the gear set  224  to perform an optical disc changing operation. It should be noted that the present invention does not limit the driving module  220  to a system with a driving motor  222  and a gear set  224 . The driving module  220  may comprises a set of levers, transmission belt or other mechanisms capable of driving the disc selecting mechanism  210  to perform an optical disc changing operation.  
      The optical control apparatus  300  mainly comprises a plate  310  and an optical sensor  320 . The optical sensor  320  is electrically connected to the control module  230 . The plate  310  rotates when driven by the control module  220  via the driving motor  222  and the gear set  224 . In addition, the disc selecting mechanism  210  and the plate  310  are driven by the driving module simultaneously. In other words, the height of the disc selecting mechanism  210  can be estimated through the angle of rotation of the plate  310 .  
       FIG. 5A  is a perspective view showing the optical control apparatus according to the first embodiment of the present invention. As shown in  FIG. 5A , the optical sensor  320  comprises a light-emitting portion  322   a  and a light-detecting portion  322   b  disposed at each side of the plate  310 . The light-emitting portion  322   a  emits a light beam  322   c  toward the light-detecting portion  322   b . At least a portion of the plate is disposed on the optical path of the light beam  322   c . It should be noted that the plate  310  has at least a detecting region  312  and a non-detecting region  314 . After rotating the plate  310  by a predetermined angle, the optical sensor  320  is able to detect the detecting region  312 .  
      According to the first embodiment of the present invention, the detecting region  312  is a transparent region and the non-detecting region  314  is an opaque region, for example. When the detecting region (the transparent region)  312  is located between the light-emitting portion  322   a  and the light-detecting portion  322   b , the light beam  322   c  emitted from the light-emitting portion  322   a  reaches the light-detecting portion  322   b  unhindered. On the contrary, when the non-detecting region (the opaque region)  314  is located between the light-emitting portion  322   a  and the light-detecting portion  322   b , the light beam  322   c  from the light-emitting portion  322   a  is prevented from reaching the light-detecting portion  322   b . The operation of the optical control apparatus is explained in more detail in the following.  
       FIG. 5B  is a diagram showing a plate blocking the light beam emitted from an optical sensor according to the present invention.  FIG. 5C  is a diagram showing a plate permitting the passage of a light beam emitted from an optical sensor according to the present invention. As shown in  FIGS. 5B and 5C , the driving module  220  drives the disc selecting mechanism  210  as well as the plate  310  simultaneously. Thus, the disc selecting mechanism  210  and the plate  310  operate simultaneously. When the non-detecting region (the opaque region)  314  of the plate  310  is located between the light-emitting portion  322   a  and the light-detecting portion  322   b , the light-detecting portion  322   b  is prevented from receiving the light beam  322   c  sent from the light-emitting portion  322   a  (as shown in  FIG. 5B ). Hence, the driving module  220  will continue to drive the disc selecting mechanism  210 . However, as the plate  310  is rotated to an angle such that the detecting region (the transparent region)  312  is located between the light-emitting portion  322   a  and the light-detecting portion  322   b , the light beam  322   c  is able to reach the light-detecting portion  322   b  (as shown in  FIG. 5C ). In this case, the optical sensor  320  outputs an electrical signal to the control module  230 . According to the electrical signal, the control module  230  instructs the driving module  220  to stop the operation so that the disc selecting mechanism  210  can stop at the required height level. It should be noted that the detecting region (the transparent region)  312  comprises one or more than one through holes or a transparent region fabricated using any transparent material and the non-detecting region  314  is an opaque region fabricated using any opaque substrate. In another embodiment, the detecting region  312  is an opaque region while the non-detecting region  314  is a transparent region, for example.  
      Assume the disc selecting mechanism  210  is used with a disc cassette capable for holding ten optical discs. And the plate  310  is designed to complete one revolution when the disc selecting mechanism  210  moves from a height level corresponding to the first optical disc to the second optical disc. Meanwhile, the light beam  322   c  is blocked and then the optical sensor  320  again detects the light beam  322   c  from the light-emitting portion  322   a  exactly once. In other words, when the disc selecting mechanism  210  moves from a height level corresponding to the first optical disc to the tenth optical disc, the plate  310  has completed exactly ten revolutions and the optical sensor  320  has detected the light beam  322   c  exactly nine times. As the number of optical disc stored inside the disc cassette is increased, there is no need to modify the plate  310  or any accessory components. The only difference between a disc drive holding a different number of optical discs is the number of rotations of the plate  310  when the disc selecting mechanism moves from the first to the last optical disc.  
      It should be noted that the number of detecting region  312  in the plate  310  is not limited to one. The plate  310  can have a multiple of detecting regions  312 . If the plate  310  only one detecting region  312 , the control module  220  will drive the plate  310  to rotate 360° and simultaneously drives the disc selecting mechanism  300  to move a unit distance (the difference in height between two neighboring discs). Similarly, if the plate  310  has 2, 3, 4, 5 or 6 detecting regions  312 , the control module  220  will drive the plate  310  to rotate 1 80°, 1 20°, 90°, 72° or 60° and simultaneously drives the disc selecting mechanism  300  to move a unit distance. In other words, if the number of detecting regions  312  in the plate  310  is a positive integer n, the plate  310  will rotate (360/n) degrees when the driving module  220  drives the disc selecting mechanism  300  to move a unit distance. In addition, the detecting region  312  in the plate  310  is not limited to a transparent region or a non-transparent region. Other types of designs can be applied to the plate  310  as well.  
       FIG. 6  is a top view of an optical control apparatus according to a second embodiment of the present invention. In the second embodiment, components identical or similar to the components in the first embodiment are labeled identically. As shown in  FIG. 6 , one major difference from the first embodiment is that the detecting region  414  of the plate  410  in the optical control apparatus  400  is a protruding section from a non-detecting region  412  of the plate  410 . The detecting region  414  is an opaque region and the non-detecting region  412  can be fabricated from any substance. When the plate  410  revolves once, the detecting region (the opaque region)  414  blocks the light beam  322   c  from the optical sensor  320  as shown in  FIG. 5B . Thereafter, the optical sensor  320  outputs an electrical signal to the control module  230  so that the control module  230  is able to control the driving module  220  as shown in  FIG. 5B . In addition, the number of detecting regions  414  in the plate  410  is not limited to one. The plate  410  can have a multiple of detecting regions  414 . It should be noted that the disposition of the light-emitting portion  322   a  and the light-detecting portion  322   b  of the optical sensor  320  in the first and the second embodiment are not limited to the respective sides of the plate  310  or  410 . The light-emitting portion  322   a  and the light-detecting portion  322   b  can be disposed at the same side of the plate  310  or  410  as described in the following.  
       FIG. 7  is a perspective view of an optical control apparatus according to a third embodiment of the present invention. As shown in  FIG. 7 , the third embodiment is similar to the first embodiment. One major difference from the first embodiment is that the light-emitting portion  522   a  and the light-detecting portion  522   b  of the optical sensor  520  are disposed at the same side of the plate  510 . In other words, the optical sensor  520  in the optical control apparatus  500  can be disposed above or below the plate  510 . Furthermore, the plate  510  comprises a detecting region  512  (for example, a reflecting region) and a non-detecting region  514  (for example, a non-reflecting region). The optical sensor  520  is designed to detect the detecting region  512 . In another embodiment, the detecting region  512  is a non-reflecting region while the non-detecting region  514  is a reflecting region. In addition, the number of detecting regions  512  in the plate  510  is not limited to one. The plate  510  can have a plurality of detecting regions  512 .  
       FIG. 8  is a top view of an optical control apparatus according to a fourth embodiment of the present invention. As shown in  FIG. 8 , the fourth embodiment is similar to the first embodiment. One major difference from the first embodiment is that the light-blocking element  610  can be indirectly driven to rotate around a central axle R through a driving module such as a set of levers or a gear set (not shown). In addition, the light-blocking element  610  has a detecting region  612  such as a reflecting region. The optical sensor  520  is designed to detect the detecting region  612  in the light-blocking element  610  and disposed on the moving path of the light-blocking element  610  such that the light-blocking element  610  can pass the optical path of the light beam emitted from the optical sensor  520 . It should be noted that the present invention does not limit the light-blocking element  610  to rotate around a central axle R. In fact, the light-blocking element  610  may move in a closed loop such as a circular path, a rectangular path or other types of regular paths. The closed loop can even be an irregular path.  
      It should be noted that the contents disclosed in the first, the second, the third and the fourth embodiment of the present invention can be combined in various ways.  
      In summary, major advantages of the optical control apparatus of the present invention includes: 
          1. The same plate or light-blocking element and optical sensor can still be used as the number of optical disc stored inside a disc cassette is increased. Only the number of rotations of the plate or the light-blocking element is altered. Since there is no need to modify the plate or the light-blocking element and the optical sensor, the optical control apparatus is unaffected by the storage capacity of the disc cassette.     2. The optical control apparatus can be directly used in different disc drives (having a capacity to hold a different number of optical discs) without any modification.        

      It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.